* [PATCH v5 5/5] tty/serial: Add Spreadtrum sc9836-uart driver support
@ 2015-01-16 10:00 ` Chunyan Zhang
0 siblings, 0 replies; 81+ messages in thread
From: Chunyan Zhang @ 2015-01-16 10:00 UTC (permalink / raw)
To: linux-arm-kernel
Add a full sc9836-uart driver for SC9836 SoC which is based on the
spreadtrum sharkl64 platform.
This driver also support earlycon.
This patch also replaced the spaces between the macros and their
values with the tabs in serial_core.h
Signed-off-by: Chunyan Zhang <chunyan.zhang@spreadtrum.com>
Signed-off-by: Orson Zhai <orson.zhai@spreadtrum.com>
Originally-by: Lanqing Liu <lanqing.liu@spreadtrum.com>
---
drivers/tty/serial/Kconfig | 18 +
drivers/tty/serial/Makefile | 1 +
drivers/tty/serial/sprd_serial.c | 772 ++++++++++++++++++++++++++++++++++++++
include/uapi/linux/serial_core.h | 3 +
4 files changed, 794 insertions(+)
create mode 100644 drivers/tty/serial/sprd_serial.c
diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
index c79b43c..969d3cd 100644
--- a/drivers/tty/serial/Kconfig
+++ b/drivers/tty/serial/Kconfig
@@ -1577,6 +1577,24 @@ config SERIAL_MEN_Z135
This driver can also be build as a module. If so, the module will be called
men_z135_uart.ko
+config SERIAL_SPRD
+ tristate "Support for SPRD serial"
+ depends on ARCH_SPRD
+ select SERIAL_CORE
+ help
+ This enables the driver for the Spreadtrum's serial.
+
+config SERIAL_SPRD_CONSOLE
+ bool "SPRD UART console support"
+ depends on SERIAL_SPRD=y
+ select SERIAL_CORE_CONSOLE
+ select SERIAL_EARLYCON
+ help
+ Support for early debug console using Spreadtrum's serial. This enables
+ the console before standard serial driver is probed. This is enabled
+ with "earlycon" on the kernel command line. The console is
+ enabled when early_param is processed.
+
endmenu
config SERIAL_MCTRL_GPIO
diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile
index 9a548ac..4801aca 100644
--- a/drivers/tty/serial/Makefile
+++ b/drivers/tty/serial/Makefile
@@ -93,6 +93,7 @@ obj-$(CONFIG_SERIAL_ARC) += arc_uart.o
obj-$(CONFIG_SERIAL_RP2) += rp2.o
obj-$(CONFIG_SERIAL_FSL_LPUART) += fsl_lpuart.o
obj-$(CONFIG_SERIAL_MEN_Z135) += men_z135_uart.o
+obj-$(CONFIG_SERIAL_SPRD) += sprd_serial.o
# GPIOLIB helpers for modem control lines
obj-$(CONFIG_SERIAL_MCTRL_GPIO) += serial_mctrl_gpio.o
diff --git a/drivers/tty/serial/sprd_serial.c b/drivers/tty/serial/sprd_serial.c
new file mode 100644
index 0000000..81839e4
--- /dev/null
+++ b/drivers/tty/serial/sprd_serial.c
@@ -0,0 +1,772 @@
+/*
+ * Copyright (C) 2012 Spreadtrum Communications Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/clk.h>
+#include <linux/console.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/serial_core.h>
+#include <linux/serial.h>
+#include <linux/slab.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+
+/* device name */
+#define UART_NR_MAX 8
+#define SPRD_TTY_NAME "ttySPX"
+#define SPRD_FIFO_SIZE 128
+#define SPRD_DEF_RATE 26000000
+#define SPRD_TIMEOUT 2048
+
+/* the offset of serial registers and BITs for them */
+/* data registers */
+#define SPRD_TXD 0x0000
+#define SPRD_RXD 0x0004
+
+/* line status register and its BITs */
+#define SPRD_LSR 0x0008
+#define SPRD_LSR_OE BIT(4)
+#define SPRD_LSR_FE BIT(3)
+#define SPRD_LSR_PE BIT(2)
+#define SPRD_LSR_BI BIT(7)
+#define SPRD_LSR_TX_OVER BIT(15)
+
+/* data number in TX and RX fifo */
+#define SPRD_STS1 0x000C
+
+/* interrupt enable register and its BITs */
+#define SPRD_IEN 0x0010
+#define SPRD_IEN_RX_FULL BIT(0)
+#define SPRD_IEN_TX_EMPTY BIT(1)
+#define SPRD_IEN_BREAK_DETECT BIT(7)
+#define SPRD_IEN_TIMEOUT BIT(13)
+
+/* interrupt clear register */
+#define SPRD_ICLR 0x0014
+
+/* line control register */
+#define SPRD_LCR 0x0018
+#define SPRD_LCR_STOP_1BIT 0x10
+#define SPRD_LCR_STOP_2BIT 0x30
+#define SPRD_LCR_DATA_LEN (BIT(2) | BIT(3))
+#define SPRD_LCR_DATA_LEN5 0x0
+#define SPRD_LCR_DATA_LEN6 0x4
+#define SPRD_LCR_DATA_LEN7 0x8
+#define SPRD_LCR_DATA_LEN8 0xc
+#define SPRD_LCR_PARITY (BIT(0) | BIT(1))
+#define SPRD_LCR_PARITY_EN 0x2
+#define SPRD_LCR_EVEN_PAR 0x0
+#define SPRD_LCR_ODD_PAR 0x1
+
+/* control register 1 */
+#define SPRD_CTL1 0x001C
+#define RX_HW_FLOW_CTL_THLD BIT(6)
+#define RX_HW_FLOW_CTL_EN BIT(7)
+#define TX_HW_FLOW_CTL_EN BIT(8)
+
+/* fifo threshold register */
+#define SPRD_CTL2 0x0020
+#define THLD_TX_EMPTY 0x40
+#define THLD_RX_FULL 0x40
+
+/* config baud rate register */
+#define SPRD_CLKD0 0x0024
+#define SPRD_CLKD1 0x0028
+
+/* interrupt mask status register */
+#define SPRD_IMSR 0x002C
+#define SPRD_IMSR_RX_FIFO_FULL BIT(0)
+#define SPRD_IMSR_TX_FIFO_EMPTY BIT(1)
+#define SPRD_IMSR_BREAK_DETECT BIT(7)
+#define SPRD_IMSR_TIMEOUT BIT(13)
+
+struct reg_backup {
+ uint32_t ien;
+ uint32_t ctrl0;
+ uint32_t ctrl1;
+ uint32_t ctrl2;
+ uint32_t clkd0;
+ uint32_t clkd1;
+ uint32_t dspwait;
+};
+
+struct sprd_uart_port {
+ struct uart_port port;
+ struct reg_backup reg_bak;
+ char name[16];
+};
+
+static struct sprd_uart_port *sprd_port[UART_NR_MAX] = { NULL };
+
+static inline unsigned int serial_in(struct uart_port *port, int offset)
+{
+ return readl_relaxed(port->membase + offset);
+}
+
+static inline void serial_out(struct uart_port *port, int offset, int value)
+{
+ writel_relaxed(value, port->membase + offset);
+}
+
+static unsigned int sprd_tx_empty(struct uart_port *port)
+{
+ if (serial_in(port, SPRD_STS1) & 0xff00)
+ return 0;
+ else
+ return TIOCSER_TEMT;
+}
+
+static unsigned int sprd_get_mctrl(struct uart_port *port)
+{
+ return TIOCM_DSR | TIOCM_CTS;
+}
+
+static void sprd_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+ /* nothing to do */
+}
+
+static void sprd_stop_tx(struct uart_port *port)
+{
+ unsigned int ien, iclr;
+
+ iclr = serial_in(port, SPRD_ICLR);
+ ien = serial_in(port, SPRD_IEN);
+
+ iclr |= SPRD_IEN_TX_EMPTY;
+ ien &= ~SPRD_IEN_TX_EMPTY;
+
+ serial_out(port, SPRD_ICLR, iclr);
+ serial_out(port, SPRD_IEN, ien);
+}
+
+static void sprd_start_tx(struct uart_port *port)
+{
+ unsigned int ien;
+
+ ien = serial_in(port, SPRD_IEN);
+ if (!(ien & SPRD_IEN_TX_EMPTY)) {
+ ien |= SPRD_IEN_TX_EMPTY;
+ serial_out(port, SPRD_IEN, ien);
+ }
+}
+
+static void sprd_stop_rx(struct uart_port *port)
+{
+ unsigned int ien, iclr;
+
+ iclr = serial_in(port, SPRD_ICLR);
+ ien = serial_in(port, SPRD_IEN);
+
+ ien &= ~(SPRD_IEN_RX_FULL | SPRD_IEN_BREAK_DETECT);
+ iclr |= SPRD_IEN_RX_FULL | SPRD_IEN_BREAK_DETECT;
+
+ serial_out(port, SPRD_IEN, ien);
+ serial_out(port, SPRD_ICLR, iclr);
+}
+
+/* The Sprd serial does not support this function. */
+static void sprd_break_ctl(struct uart_port *port, int break_state)
+{
+ /* nothing to do */
+}
+
+static inline int handle_lsr_errors(struct uart_port *port,
+ unsigned int *flag,
+ unsigned int *lsr)
+{
+ int ret = 0;
+
+ /* statistics */
+ if (*lsr & SPRD_LSR_BI) {
+ *lsr &= ~(SPRD_LSR_FE | SPRD_LSR_PE);
+ port->icount.brk++;
+ ret = uart_handle_break(port);
+ if (ret)
+ return ret;
+ } else if (*lsr & SPRD_LSR_PE)
+ port->icount.parity++;
+ else if (*lsr & SPRD_LSR_FE)
+ port->icount.frame++;
+ if (*lsr & SPRD_LSR_OE)
+ port->icount.overrun++;
+
+ /* mask off conditions which should be ignored */
+ *lsr &= port->read_status_mask;
+ if (*lsr & SPRD_LSR_BI)
+ *flag = TTY_BREAK;
+ else if (*lsr & SPRD_LSR_PE)
+ *flag = TTY_PARITY;
+ else if (*lsr & SPRD_LSR_FE)
+ *flag = TTY_FRAME;
+
+ return ret;
+}
+
+static inline void sprd_rx(int irq, void *dev_id)
+{
+ struct uart_port *port = dev_id;
+ struct tty_port *tty = &port->state->port;
+ unsigned int ch, flag, lsr, max_count = SPRD_TIMEOUT;
+
+ while ((serial_in(port, SPRD_STS1) & 0x00ff) && max_count--) {
+ lsr = serial_in(port, SPRD_LSR);
+ ch = serial_in(port, SPRD_RXD);
+ flag = TTY_NORMAL;
+ port->icount.rx++;
+
+ if (lsr & (SPRD_LSR_BI | SPRD_LSR_PE
+ | SPRD_LSR_FE | SPRD_LSR_OE))
+ if (handle_lsr_errors(port, &lsr, &flag))
+ continue;
+ if (uart_handle_sysrq_char(port, ch))
+ continue;
+
+ uart_insert_char(port, lsr, SPRD_LSR_OE, ch, flag);
+ }
+
+ tty_flip_buffer_push(tty);
+}
+
+static inline void sprd_tx(int irq, void *dev_id)
+{
+ struct uart_port *port = dev_id;
+ struct circ_buf *xmit = &port->state->xmit;
+ int count;
+
+ if (port->x_char) {
+ serial_out(port, SPRD_TXD, port->x_char);
+ port->icount.tx++;
+ port->x_char = 0;
+ return;
+ }
+
+ if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
+ sprd_stop_tx(port);
+ return;
+ }
+
+ count = THLD_TX_EMPTY;
+ do {
+ serial_out(port, SPRD_TXD, xmit->buf[xmit->tail]);
+ xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
+ port->icount.tx++;
+ if (uart_circ_empty(xmit))
+ break;
+ } while (--count > 0);
+
+ if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+ uart_write_wakeup(port);
+
+ if (uart_circ_empty(xmit))
+ sprd_stop_tx(port);
+}
+
+/* this handles the interrupt from one port */
+static irqreturn_t sprd_handle_irq(int irq, void *dev_id)
+{
+ struct uart_port *port = (struct uart_port *)dev_id;
+ unsigned int ims;
+
+ ims = serial_in(port, SPRD_IMSR);
+
+ if (!ims)
+ return IRQ_NONE;
+
+ serial_out(port, SPRD_ICLR, ~0);
+
+ if (ims & (SPRD_IMSR_RX_FIFO_FULL |
+ SPRD_IMSR_BREAK_DETECT | SPRD_IMSR_TIMEOUT))
+ sprd_rx(irq, port);
+
+ if (ims & SPRD_IMSR_TX_FIFO_EMPTY)
+ sprd_tx(irq, port);
+
+ return IRQ_HANDLED;
+}
+
+static int sprd_startup(struct uart_port *port)
+{
+ int ret = 0;
+ unsigned int ien, ctrl1;
+ unsigned int timeout;
+ struct sprd_uart_port *sp;
+
+ serial_out(port, SPRD_CTL2, ((THLD_TX_EMPTY << 8) | THLD_RX_FULL));
+
+ /* clear rx fifo */
+ timeout = SPRD_TIMEOUT;
+ while (timeout-- && serial_in(port, SPRD_STS1) & 0x00ff)
+ serial_in(port, SPRD_RXD);
+
+ /* clear tx fifo */
+ timeout = SPRD_TIMEOUT;
+ while (timeout-- && serial_in(port, SPRD_STS1) & 0xff00)
+ cpu_relax();
+
+ /* clear interrupt */
+ serial_out(port, SPRD_IEN, 0x0);
+ serial_out(port, SPRD_ICLR, ~0);
+
+ /* allocate irq */
+ sp = container_of(port, struct sprd_uart_port, port);
+ snprintf(sp->name, sizeof(sp->name), "sprd_serial%d", port->line);
+ ret = devm_request_irq(port->dev, port->irq, sprd_handle_irq,
+ IRQF_SHARED, sp->name, port);
+ if (ret) {
+ dev_err(port->dev, "fail to request serial irq %d, ret=%d\n",
+ port->irq, ret);
+ return ret;
+ }
+ ctrl1 = serial_in(port, SPRD_CTL1);
+ ctrl1 |= 0x3e00 | THLD_RX_FULL;
+ serial_out(port, SPRD_CTL1, ctrl1);
+
+ /* enable interrupt */
+ spin_lock(&port->lock);
+ ien = serial_in(port, SPRD_IEN);
+ ien |= SPRD_IEN_RX_FULL | SPRD_IEN_BREAK_DETECT | SPRD_IEN_TIMEOUT;
+ serial_out(port, SPRD_IEN, ien);
+ spin_unlock(&port->lock);
+
+ return 0;
+}
+
+static void sprd_shutdown(struct uart_port *port)
+{
+ serial_out(port, SPRD_IEN, 0x0);
+ serial_out(port, SPRD_ICLR, ~0);
+ devm_free_irq(port->dev, port->irq, port);
+}
+
+static void sprd_set_termios(struct uart_port *port,
+ struct ktermios *termios,
+ struct ktermios *old)
+{
+ unsigned int baud, quot;
+ unsigned int lcr, fc;
+
+ /* ask the core to calculate the divisor for us */
+ baud = uart_get_baud_rate(port, termios, old, 1200, 3000000);
+
+ quot = (unsigned int)((port->uartclk + baud / 2) / baud);
+
+ /* set data length */
+ lcr = serial_in(port, SPRD_LCR);
+ lcr &= ~SPRD_LCR_DATA_LEN;
+ switch (termios->c_cflag & CSIZE) {
+ case CS5:
+ lcr |= SPRD_LCR_DATA_LEN5;
+ break;
+ case CS6:
+ lcr |= SPRD_LCR_DATA_LEN6;
+ break;
+ case CS7:
+ lcr |= SPRD_LCR_DATA_LEN7;
+ break;
+ case CS8:
+ default:
+ lcr |= SPRD_LCR_DATA_LEN8;
+ break;
+ }
+
+ /* calculate stop bits */
+ lcr &= ~(SPRD_LCR_STOP_1BIT | SPRD_LCR_STOP_2BIT);
+ if (termios->c_cflag & CSTOPB)
+ lcr |= SPRD_LCR_STOP_2BIT;
+ else
+ lcr |= SPRD_LCR_STOP_1BIT;
+
+ /* calculate parity */
+ lcr &= ~SPRD_LCR_PARITY;
+ termios->c_cflag &= ~CMSPAR; /* no support mark/space */
+ if (termios->c_cflag & PARENB) {
+ lcr |= SPRD_LCR_PARITY_EN;
+ if (termios->c_cflag & PARODD)
+ lcr |= SPRD_LCR_ODD_PAR;
+ else
+ lcr |= SPRD_LCR_EVEN_PAR;
+ }
+
+ /* change the port state. */
+ /* update the per-port timeout */
+ uart_update_timeout(port, termios->c_cflag, baud);
+
+ port->read_status_mask = SPRD_LSR_OE;
+ if (termios->c_iflag & INPCK)
+ port->read_status_mask |= SPRD_LSR_FE | SPRD_LSR_PE;
+ if (termios->c_iflag & (BRKINT | PARMRK))
+ port->read_status_mask |= SPRD_LSR_BI;
+
+ /* characters to ignore */
+ port->ignore_status_mask = 0;
+ if (termios->c_iflag & IGNPAR)
+ port->ignore_status_mask |= SPRD_LSR_PE | SPRD_LSR_FE;
+ if (termios->c_iflag & IGNBRK) {
+ port->ignore_status_mask |= SPRD_LSR_BI;
+ /*
+ * If we're ignoring parity and break indicators,
+ * ignore overruns too (for real raw support).
+ */
+ if (termios->c_iflag & IGNPAR)
+ port->ignore_status_mask |= SPRD_LSR_OE;
+ }
+
+ /* flow control */
+ fc = serial_in(port, SPRD_CTL1);
+ fc &= ~(RX_HW_FLOW_CTL_THLD | RX_HW_FLOW_CTL_EN | TX_HW_FLOW_CTL_EN);
+ if (termios->c_cflag & CRTSCTS) {
+ fc |= RX_HW_FLOW_CTL_THLD;
+ fc |= RX_HW_FLOW_CTL_EN;
+ fc |= TX_HW_FLOW_CTL_EN;
+ }
+
+ /* clock divider bit0~bit15 */
+ serial_out(port, SPRD_CLKD0, quot & 0xffff);
+
+ /* clock divider bit16~bit20 */
+ serial_out(port, SPRD_CLKD1, (quot & 0x1f0000) >> 16);
+ serial_out(port, SPRD_LCR, lcr);
+ fc |= 0x3e00 | THLD_RX_FULL;
+ serial_out(port, SPRD_CTL1, fc);
+
+ /* Don't rewrite B0 */
+ if (tty_termios_baud_rate(termios))
+ tty_termios_encode_baud_rate(termios, baud, baud);
+}
+
+static const char *sprd_type(struct uart_port *port)
+{
+ return "SPX";
+}
+
+static void sprd_release_port(struct uart_port *port)
+{
+ /* nothing to do */
+}
+
+static int sprd_request_port(struct uart_port *port)
+{
+ return 0;
+}
+
+static void sprd_config_port(struct uart_port *port, int flags)
+{
+ if (flags & UART_CONFIG_TYPE)
+ port->type = PORT_SPRD;
+}
+
+static int sprd_verify_port(struct uart_port *port,
+ struct serial_struct *ser)
+{
+ if (ser->type != PORT_SPRD)
+ return -EINVAL;
+ if (port->irq != ser->irq)
+ return -EINVAL;
+ return 0;
+}
+
+static struct uart_ops serial_sprd_ops = {
+ .tx_empty = sprd_tx_empty,
+ .get_mctrl = sprd_get_mctrl,
+ .set_mctrl = sprd_set_mctrl,
+ .stop_tx = sprd_stop_tx,
+ .start_tx = sprd_start_tx,
+ .stop_rx = sprd_stop_rx,
+ .break_ctl = sprd_break_ctl,
+ .startup = sprd_startup,
+ .shutdown = sprd_shutdown,
+ .set_termios = sprd_set_termios,
+ .type = sprd_type,
+ .release_port = sprd_release_port,
+ .request_port = sprd_request_port,
+ .config_port = sprd_config_port,
+ .verify_port = sprd_verify_port,
+};
+
+#ifdef CONFIG_SERIAL_SPRD_CONSOLE
+static inline void wait_for_xmitr(struct uart_port *port)
+{
+ unsigned int status, tmout = 10000;
+
+ /* wait up to 10ms for the character(s) to be sent */
+ do {
+ status = serial_in(port, SPRD_STS1);
+ if (--tmout == 0)
+ break;
+ udelay(1);
+ } while (status & 0xff00);
+}
+
+static void sprd_console_putchar(struct uart_port *port, int ch)
+{
+ wait_for_xmitr(port);
+ serial_out(port, SPRD_TXD, ch);
+}
+
+static void sprd_console_write(struct console *co, const char *s,
+ unsigned int count)
+{
+ struct uart_port *port = &sprd_port[co->index]->port;
+ int ien;
+ int locked = 1;
+
+ if (oops_in_progress)
+ locked = spin_trylock(&port->lock);
+ else
+ spin_lock(&port->lock);
+ /* save the IEN then disable the interrupts */
+ ien = serial_in(port, SPRD_IEN);
+ serial_out(port, SPRD_IEN, 0x0);
+
+ uart_console_write(port, s, count, sprd_console_putchar);
+
+ /* wait for transmitter to become empty and restore the IEN */
+ wait_for_xmitr(port);
+ serial_out(port, SPRD_IEN, ien);
+ if (locked)
+ spin_unlock(&port->lock);
+}
+
+static int __init sprd_console_setup(struct console *co, char *options)
+{
+ struct uart_port *port;
+ int baud = 115200;
+ int bits = 8;
+ int parity = 'n';
+ int flow = 'n';
+
+ if (co->index >= UART_NR_MAX || co->index < 0)
+ co->index = 0;
+
+ port = &sprd_port[co->index]->port;
+ if (port == NULL) {
+ pr_info("serial port %d not yet initialized\n", co->index);
+ return -ENODEV;
+ }
+ if (options)
+ uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+ return uart_set_options(port, co, baud, parity, bits, flow);
+}
+
+static struct uart_driver sprd_uart_driver;
+static struct console sprd_console = {
+ .name = SPRD_TTY_NAME,
+ .write = sprd_console_write,
+ .device = uart_console_device,
+ .setup = sprd_console_setup,
+ .flags = CON_PRINTBUFFER,
+ .index = -1,
+ .data = &sprd_uart_driver,
+};
+
+#define SPRD_CONSOLE (&sprd_console)
+
+/* Support for earlycon */
+static void sprd_putc(struct uart_port *port, int c)
+{
+ unsigned int timeout = SPRD_TIMEOUT;
+
+ while (timeout-- &&
+ !(readl(port->membase + SPRD_LSR) & SPRD_LSR_TX_OVER))
+ cpu_relax();
+
+ writeb(c, port->membase + SPRD_TXD);
+}
+
+static void sprd_early_write(struct console *con, const char *s,
+ unsigned n)
+{
+ struct earlycon_device *dev = con->data;
+
+ uart_console_write(&dev->port, s, n, sprd_putc);
+}
+
+static int __init sprd_early_console_setup(
+ struct earlycon_device *device,
+ const char *opt)
+{
+ if (!device->port.membase)
+ return -ENODEV;
+
+ device->con->write = sprd_early_write;
+ return 0;
+}
+
+EARLYCON_DECLARE(sprd_serial, sprd_early_console_setup);
+OF_EARLYCON_DECLARE(sprd_serial, "sprd,sc9836-uart",
+ sprd_early_console_setup);
+
+#else /* !CONFIG_SERIAL_SPRD_CONSOLE */
+#define SPRD_CONSOLE NULL
+#endif
+
+static struct uart_driver sprd_uart_driver = {
+ .owner = THIS_MODULE,
+ .driver_name = "sprd_serial",
+ .dev_name = SPRD_TTY_NAME,
+ .major = 0,
+ .minor = 0,
+ .nr = UART_NR_MAX,
+ .cons = SPRD_CONSOLE,
+};
+
+static int sprd_probe(struct platform_device *pdev)
+{
+ struct resource *res;
+ struct device_node *np = pdev->dev.of_node;
+ struct uart_port *up;
+ struct clk *clk;
+ int irq;
+
+ if (np)
+ pdev->id = of_alias_get_id(np, "serial");
+
+ if (pdev->id < 0 || pdev->id >= UART_NR_MAX) {
+ dev_err(&pdev->dev, "does not support id %d\n", pdev->id);
+ return -ENXIO;
+ }
+
+ sprd_port[pdev->id] = devm_kzalloc(&pdev->dev,
+ sizeof(*sprd_port[pdev->id]), GFP_KERNEL);
+ if (!sprd_port[pdev->id])
+ return -ENOMEM;
+
+ up = &sprd_port[pdev->id]->port;
+ up->dev = &pdev->dev;
+ up->line = pdev->id;
+ up->type = PORT_SPRD;
+ up->iotype = SERIAL_IO_PORT;
+ up->uartclk = SPRD_DEF_RATE;
+ up->fifosize = SPRD_FIFO_SIZE;
+ up->ops = &serial_sprd_ops;
+ up->flags = ASYNC_BOOT_AUTOCONF;
+
+ clk = devm_clk_get(&pdev->dev, NULL);
+ if (!IS_ERR(clk))
+ up->uartclk = clk_get_rate(clk);
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res) {
+ dev_err(&pdev->dev, "not provide mem resource\n");
+ return -ENODEV;
+ }
+ up->mapbase = res->start;
+ up->membase = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(up->membase))
+ return PTR_ERR(up->membase);
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0) {
+ dev_err(&pdev->dev, "not provide irq resource\n");
+ return -ENODEV;
+ }
+ up->irq = irq;
+
+ platform_set_drvdata(pdev, up);
+
+ return uart_add_one_port(&sprd_uart_driver, up);
+}
+
+static int sprd_remove(struct platform_device *dev)
+{
+ struct uart_port *up = platform_get_drvdata(dev);
+
+ return uart_remove_one_port(&sprd_uart_driver, up);
+}
+
+static int sprd_suspend(struct device *dev)
+{
+ int id = to_platform_device(dev)->id;
+ struct uart_port *port = &sprd_port[id]->port;
+ struct reg_backup *reg_bak = &sprd_port[id]->reg_bak;
+
+ reg_bak->ien = serial_in(port, SPRD_IEN);
+ reg_bak->ctrl0 = serial_in(port, SPRD_LCR);
+ reg_bak->ctrl1 = serial_in(port, SPRD_CTL1);
+ reg_bak->ctrl2 = serial_in(port, SPRD_CTL2);
+ reg_bak->clkd0 = serial_in(port, SPRD_CLKD0);
+ reg_bak->clkd1 = serial_in(port, SPRD_CLKD1);
+
+ uart_suspend_port(&sprd_uart_driver, port);
+
+ return 0;
+}
+
+static int sprd_resume(struct device *dev)
+{
+ int id = to_platform_device(dev)->id;
+ struct uart_port *port = &sprd_port[id]->port;
+ struct reg_backup *reg_bak = &sprd_port[id]->reg_bak;
+
+ serial_out(port, SPRD_LCR, reg_bak->ctrl0);
+ serial_out(port, SPRD_CTL1, reg_bak->ctrl1);
+ serial_out(port, SPRD_CTL2, reg_bak->ctrl2);
+ serial_out(port, SPRD_CLKD0, reg_bak->clkd0);
+ serial_out(port, SPRD_CLKD1, reg_bak->clkd1);
+ serial_out(port, SPRD_IEN, reg_bak->ien);
+
+ uart_resume_port(&sprd_uart_driver, port);
+
+ return 0;
+}
+
+static const struct of_device_id serial_ids[] = {
+ {.compatible = "sprd,sc9836-uart",},
+ {}
+};
+
+static SIMPLE_DEV_PM_OPS(sprd_pm_ops, sprd_suspend, sprd_resume);
+
+static struct platform_driver sprd_platform_driver = {
+ .probe = sprd_probe,
+ .remove = sprd_remove,
+ .driver = {
+ .name = "sprd_serial",
+ .of_match_table = of_match_ptr(serial_ids),
+ .pm = &sprd_pm_ops,
+ },
+};
+
+static int __init sprd_serial_init(void)
+{
+ int ret = 0;
+
+ ret = uart_register_driver(&sprd_uart_driver);
+ if (ret)
+ return ret;
+
+ ret = platform_driver_register(&sprd_platform_driver);
+ if (ret)
+ uart_unregister_driver(&sprd_uart_driver);
+
+ return ret;
+}
+
+static void __exit sprd_serial_exit(void)
+{
+ platform_driver_unregister(&sprd_platform_driver);
+ uart_unregister_driver(&sprd_uart_driver);
+}
+
+module_init(sprd_serial_init);
+module_exit(sprd_serial_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Spreadtrum SoC serial driver series");
diff --git a/include/uapi/linux/serial_core.h b/include/uapi/linux/serial_core.h
index c172180..7e6eb39 100644
--- a/include/uapi/linux/serial_core.h
+++ b/include/uapi/linux/serial_core.h
@@ -248,4 +248,7 @@
/* MESON */
#define PORT_MESON 109
+/* SPRD SERIAL */
+#define PORT_SPRD 110
+
#endif /* _UAPILINUX_SERIAL_CORE_H */
--
1.7.9.5
^ permalink raw reply related [flat|nested] 81+ messages in thread* [PATCH v5 5/5] tty/serial: Add Spreadtrum sc9836-uart driver support
@ 2015-01-16 10:00 ` Chunyan Zhang
0 siblings, 0 replies; 81+ messages in thread
From: Chunyan Zhang @ 2015-01-16 10:00 UTC (permalink / raw)
To: gregkh, mark.rutland, arnd, gnomes, broonie, robh+dt, pawel.moll,
ijc+devicetree, galak, will.deacon, catalin.marinas, jslaby,
jason, heiko, florian.vaussard, andrew, rrichter, hytszk,
grant.likely, antonynpavlov, Joel.Schopp, Suravee.Suthikulpanit,
shawn.guo, lea.yan, jorge.ramirez-ortiz, lee.jones, orsonzhai,
geng.ren, zhizhou.zhang, lanqing.liu, zhang.lyra, wei.qiao
Cc: devicetree, linux-api, linux-kernel, linux-arm-kernel, linux-serial
Add a full sc9836-uart driver for SC9836 SoC which is based on the
spreadtrum sharkl64 platform.
This driver also support earlycon.
This patch also replaced the spaces between the macros and their
values with the tabs in serial_core.h
Signed-off-by: Chunyan Zhang <chunyan.zhang@spreadtrum.com>
Signed-off-by: Orson Zhai <orson.zhai@spreadtrum.com>
Originally-by: Lanqing Liu <lanqing.liu@spreadtrum.com>
---
drivers/tty/serial/Kconfig | 18 +
drivers/tty/serial/Makefile | 1 +
drivers/tty/serial/sprd_serial.c | 772 ++++++++++++++++++++++++++++++++++++++
include/uapi/linux/serial_core.h | 3 +
4 files changed, 794 insertions(+)
create mode 100644 drivers/tty/serial/sprd_serial.c
diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
index c79b43c..969d3cd 100644
--- a/drivers/tty/serial/Kconfig
+++ b/drivers/tty/serial/Kconfig
@@ -1577,6 +1577,24 @@ config SERIAL_MEN_Z135
This driver can also be build as a module. If so, the module will be called
men_z135_uart.ko
+config SERIAL_SPRD
+ tristate "Support for SPRD serial"
+ depends on ARCH_SPRD
+ select SERIAL_CORE
+ help
+ This enables the driver for the Spreadtrum's serial.
+
+config SERIAL_SPRD_CONSOLE
+ bool "SPRD UART console support"
+ depends on SERIAL_SPRD=y
+ select SERIAL_CORE_CONSOLE
+ select SERIAL_EARLYCON
+ help
+ Support for early debug console using Spreadtrum's serial. This enables
+ the console before standard serial driver is probed. This is enabled
+ with "earlycon" on the kernel command line. The console is
+ enabled when early_param is processed.
+
endmenu
config SERIAL_MCTRL_GPIO
diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile
index 9a548ac..4801aca 100644
--- a/drivers/tty/serial/Makefile
+++ b/drivers/tty/serial/Makefile
@@ -93,6 +93,7 @@ obj-$(CONFIG_SERIAL_ARC) += arc_uart.o
obj-$(CONFIG_SERIAL_RP2) += rp2.o
obj-$(CONFIG_SERIAL_FSL_LPUART) += fsl_lpuart.o
obj-$(CONFIG_SERIAL_MEN_Z135) += men_z135_uart.o
+obj-$(CONFIG_SERIAL_SPRD) += sprd_serial.o
# GPIOLIB helpers for modem control lines
obj-$(CONFIG_SERIAL_MCTRL_GPIO) += serial_mctrl_gpio.o
diff --git a/drivers/tty/serial/sprd_serial.c b/drivers/tty/serial/sprd_serial.c
new file mode 100644
index 0000000..81839e4
--- /dev/null
+++ b/drivers/tty/serial/sprd_serial.c
@@ -0,0 +1,772 @@
+/*
+ * Copyright (C) 2012 Spreadtrum Communications Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/clk.h>
+#include <linux/console.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/serial_core.h>
+#include <linux/serial.h>
+#include <linux/slab.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+
+/* device name */
+#define UART_NR_MAX 8
+#define SPRD_TTY_NAME "ttySPX"
+#define SPRD_FIFO_SIZE 128
+#define SPRD_DEF_RATE 26000000
+#define SPRD_TIMEOUT 2048
+
+/* the offset of serial registers and BITs for them */
+/* data registers */
+#define SPRD_TXD 0x0000
+#define SPRD_RXD 0x0004
+
+/* line status register and its BITs */
+#define SPRD_LSR 0x0008
+#define SPRD_LSR_OE BIT(4)
+#define SPRD_LSR_FE BIT(3)
+#define SPRD_LSR_PE BIT(2)
+#define SPRD_LSR_BI BIT(7)
+#define SPRD_LSR_TX_OVER BIT(15)
+
+/* data number in TX and RX fifo */
+#define SPRD_STS1 0x000C
+
+/* interrupt enable register and its BITs */
+#define SPRD_IEN 0x0010
+#define SPRD_IEN_RX_FULL BIT(0)
+#define SPRD_IEN_TX_EMPTY BIT(1)
+#define SPRD_IEN_BREAK_DETECT BIT(7)
+#define SPRD_IEN_TIMEOUT BIT(13)
+
+/* interrupt clear register */
+#define SPRD_ICLR 0x0014
+
+/* line control register */
+#define SPRD_LCR 0x0018
+#define SPRD_LCR_STOP_1BIT 0x10
+#define SPRD_LCR_STOP_2BIT 0x30
+#define SPRD_LCR_DATA_LEN (BIT(2) | BIT(3))
+#define SPRD_LCR_DATA_LEN5 0x0
+#define SPRD_LCR_DATA_LEN6 0x4
+#define SPRD_LCR_DATA_LEN7 0x8
+#define SPRD_LCR_DATA_LEN8 0xc
+#define SPRD_LCR_PARITY (BIT(0) | BIT(1))
+#define SPRD_LCR_PARITY_EN 0x2
+#define SPRD_LCR_EVEN_PAR 0x0
+#define SPRD_LCR_ODD_PAR 0x1
+
+/* control register 1 */
+#define SPRD_CTL1 0x001C
+#define RX_HW_FLOW_CTL_THLD BIT(6)
+#define RX_HW_FLOW_CTL_EN BIT(7)
+#define TX_HW_FLOW_CTL_EN BIT(8)
+
+/* fifo threshold register */
+#define SPRD_CTL2 0x0020
+#define THLD_TX_EMPTY 0x40
+#define THLD_RX_FULL 0x40
+
+/* config baud rate register */
+#define SPRD_CLKD0 0x0024
+#define SPRD_CLKD1 0x0028
+
+/* interrupt mask status register */
+#define SPRD_IMSR 0x002C
+#define SPRD_IMSR_RX_FIFO_FULL BIT(0)
+#define SPRD_IMSR_TX_FIFO_EMPTY BIT(1)
+#define SPRD_IMSR_BREAK_DETECT BIT(7)
+#define SPRD_IMSR_TIMEOUT BIT(13)
+
+struct reg_backup {
+ uint32_t ien;
+ uint32_t ctrl0;
+ uint32_t ctrl1;
+ uint32_t ctrl2;
+ uint32_t clkd0;
+ uint32_t clkd1;
+ uint32_t dspwait;
+};
+
+struct sprd_uart_port {
+ struct uart_port port;
+ struct reg_backup reg_bak;
+ char name[16];
+};
+
+static struct sprd_uart_port *sprd_port[UART_NR_MAX] = { NULL };
+
+static inline unsigned int serial_in(struct uart_port *port, int offset)
+{
+ return readl_relaxed(port->membase + offset);
+}
+
+static inline void serial_out(struct uart_port *port, int offset, int value)
+{
+ writel_relaxed(value, port->membase + offset);
+}
+
+static unsigned int sprd_tx_empty(struct uart_port *port)
+{
+ if (serial_in(port, SPRD_STS1) & 0xff00)
+ return 0;
+ else
+ return TIOCSER_TEMT;
+}
+
+static unsigned int sprd_get_mctrl(struct uart_port *port)
+{
+ return TIOCM_DSR | TIOCM_CTS;
+}
+
+static void sprd_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+ /* nothing to do */
+}
+
+static void sprd_stop_tx(struct uart_port *port)
+{
+ unsigned int ien, iclr;
+
+ iclr = serial_in(port, SPRD_ICLR);
+ ien = serial_in(port, SPRD_IEN);
+
+ iclr |= SPRD_IEN_TX_EMPTY;
+ ien &= ~SPRD_IEN_TX_EMPTY;
+
+ serial_out(port, SPRD_ICLR, iclr);
+ serial_out(port, SPRD_IEN, ien);
+}
+
+static void sprd_start_tx(struct uart_port *port)
+{
+ unsigned int ien;
+
+ ien = serial_in(port, SPRD_IEN);
+ if (!(ien & SPRD_IEN_TX_EMPTY)) {
+ ien |= SPRD_IEN_TX_EMPTY;
+ serial_out(port, SPRD_IEN, ien);
+ }
+}
+
+static void sprd_stop_rx(struct uart_port *port)
+{
+ unsigned int ien, iclr;
+
+ iclr = serial_in(port, SPRD_ICLR);
+ ien = serial_in(port, SPRD_IEN);
+
+ ien &= ~(SPRD_IEN_RX_FULL | SPRD_IEN_BREAK_DETECT);
+ iclr |= SPRD_IEN_RX_FULL | SPRD_IEN_BREAK_DETECT;
+
+ serial_out(port, SPRD_IEN, ien);
+ serial_out(port, SPRD_ICLR, iclr);
+}
+
+/* The Sprd serial does not support this function. */
+static void sprd_break_ctl(struct uart_port *port, int break_state)
+{
+ /* nothing to do */
+}
+
+static inline int handle_lsr_errors(struct uart_port *port,
+ unsigned int *flag,
+ unsigned int *lsr)
+{
+ int ret = 0;
+
+ /* statistics */
+ if (*lsr & SPRD_LSR_BI) {
+ *lsr &= ~(SPRD_LSR_FE | SPRD_LSR_PE);
+ port->icount.brk++;
+ ret = uart_handle_break(port);
+ if (ret)
+ return ret;
+ } else if (*lsr & SPRD_LSR_PE)
+ port->icount.parity++;
+ else if (*lsr & SPRD_LSR_FE)
+ port->icount.frame++;
+ if (*lsr & SPRD_LSR_OE)
+ port->icount.overrun++;
+
+ /* mask off conditions which should be ignored */
+ *lsr &= port->read_status_mask;
+ if (*lsr & SPRD_LSR_BI)
+ *flag = TTY_BREAK;
+ else if (*lsr & SPRD_LSR_PE)
+ *flag = TTY_PARITY;
+ else if (*lsr & SPRD_LSR_FE)
+ *flag = TTY_FRAME;
+
+ return ret;
+}
+
+static inline void sprd_rx(int irq, void *dev_id)
+{
+ struct uart_port *port = dev_id;
+ struct tty_port *tty = &port->state->port;
+ unsigned int ch, flag, lsr, max_count = SPRD_TIMEOUT;
+
+ while ((serial_in(port, SPRD_STS1) & 0x00ff) && max_count--) {
+ lsr = serial_in(port, SPRD_LSR);
+ ch = serial_in(port, SPRD_RXD);
+ flag = TTY_NORMAL;
+ port->icount.rx++;
+
+ if (lsr & (SPRD_LSR_BI | SPRD_LSR_PE
+ | SPRD_LSR_FE | SPRD_LSR_OE))
+ if (handle_lsr_errors(port, &lsr, &flag))
+ continue;
+ if (uart_handle_sysrq_char(port, ch))
+ continue;
+
+ uart_insert_char(port, lsr, SPRD_LSR_OE, ch, flag);
+ }
+
+ tty_flip_buffer_push(tty);
+}
+
+static inline void sprd_tx(int irq, void *dev_id)
+{
+ struct uart_port *port = dev_id;
+ struct circ_buf *xmit = &port->state->xmit;
+ int count;
+
+ if (port->x_char) {
+ serial_out(port, SPRD_TXD, port->x_char);
+ port->icount.tx++;
+ port->x_char = 0;
+ return;
+ }
+
+ if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
+ sprd_stop_tx(port);
+ return;
+ }
+
+ count = THLD_TX_EMPTY;
+ do {
+ serial_out(port, SPRD_TXD, xmit->buf[xmit->tail]);
+ xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
+ port->icount.tx++;
+ if (uart_circ_empty(xmit))
+ break;
+ } while (--count > 0);
+
+ if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+ uart_write_wakeup(port);
+
+ if (uart_circ_empty(xmit))
+ sprd_stop_tx(port);
+}
+
+/* this handles the interrupt from one port */
+static irqreturn_t sprd_handle_irq(int irq, void *dev_id)
+{
+ struct uart_port *port = (struct uart_port *)dev_id;
+ unsigned int ims;
+
+ ims = serial_in(port, SPRD_IMSR);
+
+ if (!ims)
+ return IRQ_NONE;
+
+ serial_out(port, SPRD_ICLR, ~0);
+
+ if (ims & (SPRD_IMSR_RX_FIFO_FULL |
+ SPRD_IMSR_BREAK_DETECT | SPRD_IMSR_TIMEOUT))
+ sprd_rx(irq, port);
+
+ if (ims & SPRD_IMSR_TX_FIFO_EMPTY)
+ sprd_tx(irq, port);
+
+ return IRQ_HANDLED;
+}
+
+static int sprd_startup(struct uart_port *port)
+{
+ int ret = 0;
+ unsigned int ien, ctrl1;
+ unsigned int timeout;
+ struct sprd_uart_port *sp;
+
+ serial_out(port, SPRD_CTL2, ((THLD_TX_EMPTY << 8) | THLD_RX_FULL));
+
+ /* clear rx fifo */
+ timeout = SPRD_TIMEOUT;
+ while (timeout-- && serial_in(port, SPRD_STS1) & 0x00ff)
+ serial_in(port, SPRD_RXD);
+
+ /* clear tx fifo */
+ timeout = SPRD_TIMEOUT;
+ while (timeout-- && serial_in(port, SPRD_STS1) & 0xff00)
+ cpu_relax();
+
+ /* clear interrupt */
+ serial_out(port, SPRD_IEN, 0x0);
+ serial_out(port, SPRD_ICLR, ~0);
+
+ /* allocate irq */
+ sp = container_of(port, struct sprd_uart_port, port);
+ snprintf(sp->name, sizeof(sp->name), "sprd_serial%d", port->line);
+ ret = devm_request_irq(port->dev, port->irq, sprd_handle_irq,
+ IRQF_SHARED, sp->name, port);
+ if (ret) {
+ dev_err(port->dev, "fail to request serial irq %d, ret=%d\n",
+ port->irq, ret);
+ return ret;
+ }
+ ctrl1 = serial_in(port, SPRD_CTL1);
+ ctrl1 |= 0x3e00 | THLD_RX_FULL;
+ serial_out(port, SPRD_CTL1, ctrl1);
+
+ /* enable interrupt */
+ spin_lock(&port->lock);
+ ien = serial_in(port, SPRD_IEN);
+ ien |= SPRD_IEN_RX_FULL | SPRD_IEN_BREAK_DETECT | SPRD_IEN_TIMEOUT;
+ serial_out(port, SPRD_IEN, ien);
+ spin_unlock(&port->lock);
+
+ return 0;
+}
+
+static void sprd_shutdown(struct uart_port *port)
+{
+ serial_out(port, SPRD_IEN, 0x0);
+ serial_out(port, SPRD_ICLR, ~0);
+ devm_free_irq(port->dev, port->irq, port);
+}
+
+static void sprd_set_termios(struct uart_port *port,
+ struct ktermios *termios,
+ struct ktermios *old)
+{
+ unsigned int baud, quot;
+ unsigned int lcr, fc;
+
+ /* ask the core to calculate the divisor for us */
+ baud = uart_get_baud_rate(port, termios, old, 1200, 3000000);
+
+ quot = (unsigned int)((port->uartclk + baud / 2) / baud);
+
+ /* set data length */
+ lcr = serial_in(port, SPRD_LCR);
+ lcr &= ~SPRD_LCR_DATA_LEN;
+ switch (termios->c_cflag & CSIZE) {
+ case CS5:
+ lcr |= SPRD_LCR_DATA_LEN5;
+ break;
+ case CS6:
+ lcr |= SPRD_LCR_DATA_LEN6;
+ break;
+ case CS7:
+ lcr |= SPRD_LCR_DATA_LEN7;
+ break;
+ case CS8:
+ default:
+ lcr |= SPRD_LCR_DATA_LEN8;
+ break;
+ }
+
+ /* calculate stop bits */
+ lcr &= ~(SPRD_LCR_STOP_1BIT | SPRD_LCR_STOP_2BIT);
+ if (termios->c_cflag & CSTOPB)
+ lcr |= SPRD_LCR_STOP_2BIT;
+ else
+ lcr |= SPRD_LCR_STOP_1BIT;
+
+ /* calculate parity */
+ lcr &= ~SPRD_LCR_PARITY;
+ termios->c_cflag &= ~CMSPAR; /* no support mark/space */
+ if (termios->c_cflag & PARENB) {
+ lcr |= SPRD_LCR_PARITY_EN;
+ if (termios->c_cflag & PARODD)
+ lcr |= SPRD_LCR_ODD_PAR;
+ else
+ lcr |= SPRD_LCR_EVEN_PAR;
+ }
+
+ /* change the port state. */
+ /* update the per-port timeout */
+ uart_update_timeout(port, termios->c_cflag, baud);
+
+ port->read_status_mask = SPRD_LSR_OE;
+ if (termios->c_iflag & INPCK)
+ port->read_status_mask |= SPRD_LSR_FE | SPRD_LSR_PE;
+ if (termios->c_iflag & (BRKINT | PARMRK))
+ port->read_status_mask |= SPRD_LSR_BI;
+
+ /* characters to ignore */
+ port->ignore_status_mask = 0;
+ if (termios->c_iflag & IGNPAR)
+ port->ignore_status_mask |= SPRD_LSR_PE | SPRD_LSR_FE;
+ if (termios->c_iflag & IGNBRK) {
+ port->ignore_status_mask |= SPRD_LSR_BI;
+ /*
+ * If we're ignoring parity and break indicators,
+ * ignore overruns too (for real raw support).
+ */
+ if (termios->c_iflag & IGNPAR)
+ port->ignore_status_mask |= SPRD_LSR_OE;
+ }
+
+ /* flow control */
+ fc = serial_in(port, SPRD_CTL1);
+ fc &= ~(RX_HW_FLOW_CTL_THLD | RX_HW_FLOW_CTL_EN | TX_HW_FLOW_CTL_EN);
+ if (termios->c_cflag & CRTSCTS) {
+ fc |= RX_HW_FLOW_CTL_THLD;
+ fc |= RX_HW_FLOW_CTL_EN;
+ fc |= TX_HW_FLOW_CTL_EN;
+ }
+
+ /* clock divider bit0~bit15 */
+ serial_out(port, SPRD_CLKD0, quot & 0xffff);
+
+ /* clock divider bit16~bit20 */
+ serial_out(port, SPRD_CLKD1, (quot & 0x1f0000) >> 16);
+ serial_out(port, SPRD_LCR, lcr);
+ fc |= 0x3e00 | THLD_RX_FULL;
+ serial_out(port, SPRD_CTL1, fc);
+
+ /* Don't rewrite B0 */
+ if (tty_termios_baud_rate(termios))
+ tty_termios_encode_baud_rate(termios, baud, baud);
+}
+
+static const char *sprd_type(struct uart_port *port)
+{
+ return "SPX";
+}
+
+static void sprd_release_port(struct uart_port *port)
+{
+ /* nothing to do */
+}
+
+static int sprd_request_port(struct uart_port *port)
+{
+ return 0;
+}
+
+static void sprd_config_port(struct uart_port *port, int flags)
+{
+ if (flags & UART_CONFIG_TYPE)
+ port->type = PORT_SPRD;
+}
+
+static int sprd_verify_port(struct uart_port *port,
+ struct serial_struct *ser)
+{
+ if (ser->type != PORT_SPRD)
+ return -EINVAL;
+ if (port->irq != ser->irq)
+ return -EINVAL;
+ return 0;
+}
+
+static struct uart_ops serial_sprd_ops = {
+ .tx_empty = sprd_tx_empty,
+ .get_mctrl = sprd_get_mctrl,
+ .set_mctrl = sprd_set_mctrl,
+ .stop_tx = sprd_stop_tx,
+ .start_tx = sprd_start_tx,
+ .stop_rx = sprd_stop_rx,
+ .break_ctl = sprd_break_ctl,
+ .startup = sprd_startup,
+ .shutdown = sprd_shutdown,
+ .set_termios = sprd_set_termios,
+ .type = sprd_type,
+ .release_port = sprd_release_port,
+ .request_port = sprd_request_port,
+ .config_port = sprd_config_port,
+ .verify_port = sprd_verify_port,
+};
+
+#ifdef CONFIG_SERIAL_SPRD_CONSOLE
+static inline void wait_for_xmitr(struct uart_port *port)
+{
+ unsigned int status, tmout = 10000;
+
+ /* wait up to 10ms for the character(s) to be sent */
+ do {
+ status = serial_in(port, SPRD_STS1);
+ if (--tmout == 0)
+ break;
+ udelay(1);
+ } while (status & 0xff00);
+}
+
+static void sprd_console_putchar(struct uart_port *port, int ch)
+{
+ wait_for_xmitr(port);
+ serial_out(port, SPRD_TXD, ch);
+}
+
+static void sprd_console_write(struct console *co, const char *s,
+ unsigned int count)
+{
+ struct uart_port *port = &sprd_port[co->index]->port;
+ int ien;
+ int locked = 1;
+
+ if (oops_in_progress)
+ locked = spin_trylock(&port->lock);
+ else
+ spin_lock(&port->lock);
+ /* save the IEN then disable the interrupts */
+ ien = serial_in(port, SPRD_IEN);
+ serial_out(port, SPRD_IEN, 0x0);
+
+ uart_console_write(port, s, count, sprd_console_putchar);
+
+ /* wait for transmitter to become empty and restore the IEN */
+ wait_for_xmitr(port);
+ serial_out(port, SPRD_IEN, ien);
+ if (locked)
+ spin_unlock(&port->lock);
+}
+
+static int __init sprd_console_setup(struct console *co, char *options)
+{
+ struct uart_port *port;
+ int baud = 115200;
+ int bits = 8;
+ int parity = 'n';
+ int flow = 'n';
+
+ if (co->index >= UART_NR_MAX || co->index < 0)
+ co->index = 0;
+
+ port = &sprd_port[co->index]->port;
+ if (port == NULL) {
+ pr_info("serial port %d not yet initialized\n", co->index);
+ return -ENODEV;
+ }
+ if (options)
+ uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+ return uart_set_options(port, co, baud, parity, bits, flow);
+}
+
+static struct uart_driver sprd_uart_driver;
+static struct console sprd_console = {
+ .name = SPRD_TTY_NAME,
+ .write = sprd_console_write,
+ .device = uart_console_device,
+ .setup = sprd_console_setup,
+ .flags = CON_PRINTBUFFER,
+ .index = -1,
+ .data = &sprd_uart_driver,
+};
+
+#define SPRD_CONSOLE (&sprd_console)
+
+/* Support for earlycon */
+static void sprd_putc(struct uart_port *port, int c)
+{
+ unsigned int timeout = SPRD_TIMEOUT;
+
+ while (timeout-- &&
+ !(readl(port->membase + SPRD_LSR) & SPRD_LSR_TX_OVER))
+ cpu_relax();
+
+ writeb(c, port->membase + SPRD_TXD);
+}
+
+static void sprd_early_write(struct console *con, const char *s,
+ unsigned n)
+{
+ struct earlycon_device *dev = con->data;
+
+ uart_console_write(&dev->port, s, n, sprd_putc);
+}
+
+static int __init sprd_early_console_setup(
+ struct earlycon_device *device,
+ const char *opt)
+{
+ if (!device->port.membase)
+ return -ENODEV;
+
+ device->con->write = sprd_early_write;
+ return 0;
+}
+
+EARLYCON_DECLARE(sprd_serial, sprd_early_console_setup);
+OF_EARLYCON_DECLARE(sprd_serial, "sprd,sc9836-uart",
+ sprd_early_console_setup);
+
+#else /* !CONFIG_SERIAL_SPRD_CONSOLE */
+#define SPRD_CONSOLE NULL
+#endif
+
+static struct uart_driver sprd_uart_driver = {
+ .owner = THIS_MODULE,
+ .driver_name = "sprd_serial",
+ .dev_name = SPRD_TTY_NAME,
+ .major = 0,
+ .minor = 0,
+ .nr = UART_NR_MAX,
+ .cons = SPRD_CONSOLE,
+};
+
+static int sprd_probe(struct platform_device *pdev)
+{
+ struct resource *res;
+ struct device_node *np = pdev->dev.of_node;
+ struct uart_port *up;
+ struct clk *clk;
+ int irq;
+
+ if (np)
+ pdev->id = of_alias_get_id(np, "serial");
+
+ if (pdev->id < 0 || pdev->id >= UART_NR_MAX) {
+ dev_err(&pdev->dev, "does not support id %d\n", pdev->id);
+ return -ENXIO;
+ }
+
+ sprd_port[pdev->id] = devm_kzalloc(&pdev->dev,
+ sizeof(*sprd_port[pdev->id]), GFP_KERNEL);
+ if (!sprd_port[pdev->id])
+ return -ENOMEM;
+
+ up = &sprd_port[pdev->id]->port;
+ up->dev = &pdev->dev;
+ up->line = pdev->id;
+ up->type = PORT_SPRD;
+ up->iotype = SERIAL_IO_PORT;
+ up->uartclk = SPRD_DEF_RATE;
+ up->fifosize = SPRD_FIFO_SIZE;
+ up->ops = &serial_sprd_ops;
+ up->flags = ASYNC_BOOT_AUTOCONF;
+
+ clk = devm_clk_get(&pdev->dev, NULL);
+ if (!IS_ERR(clk))
+ up->uartclk = clk_get_rate(clk);
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res) {
+ dev_err(&pdev->dev, "not provide mem resource\n");
+ return -ENODEV;
+ }
+ up->mapbase = res->start;
+ up->membase = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(up->membase))
+ return PTR_ERR(up->membase);
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0) {
+ dev_err(&pdev->dev, "not provide irq resource\n");
+ return -ENODEV;
+ }
+ up->irq = irq;
+
+ platform_set_drvdata(pdev, up);
+
+ return uart_add_one_port(&sprd_uart_driver, up);
+}
+
+static int sprd_remove(struct platform_device *dev)
+{
+ struct uart_port *up = platform_get_drvdata(dev);
+
+ return uart_remove_one_port(&sprd_uart_driver, up);
+}
+
+static int sprd_suspend(struct device *dev)
+{
+ int id = to_platform_device(dev)->id;
+ struct uart_port *port = &sprd_port[id]->port;
+ struct reg_backup *reg_bak = &sprd_port[id]->reg_bak;
+
+ reg_bak->ien = serial_in(port, SPRD_IEN);
+ reg_bak->ctrl0 = serial_in(port, SPRD_LCR);
+ reg_bak->ctrl1 = serial_in(port, SPRD_CTL1);
+ reg_bak->ctrl2 = serial_in(port, SPRD_CTL2);
+ reg_bak->clkd0 = serial_in(port, SPRD_CLKD0);
+ reg_bak->clkd1 = serial_in(port, SPRD_CLKD1);
+
+ uart_suspend_port(&sprd_uart_driver, port);
+
+ return 0;
+}
+
+static int sprd_resume(struct device *dev)
+{
+ int id = to_platform_device(dev)->id;
+ struct uart_port *port = &sprd_port[id]->port;
+ struct reg_backup *reg_bak = &sprd_port[id]->reg_bak;
+
+ serial_out(port, SPRD_LCR, reg_bak->ctrl0);
+ serial_out(port, SPRD_CTL1, reg_bak->ctrl1);
+ serial_out(port, SPRD_CTL2, reg_bak->ctrl2);
+ serial_out(port, SPRD_CLKD0, reg_bak->clkd0);
+ serial_out(port, SPRD_CLKD1, reg_bak->clkd1);
+ serial_out(port, SPRD_IEN, reg_bak->ien);
+
+ uart_resume_port(&sprd_uart_driver, port);
+
+ return 0;
+}
+
+static const struct of_device_id serial_ids[] = {
+ {.compatible = "sprd,sc9836-uart",},
+ {}
+};
+
+static SIMPLE_DEV_PM_OPS(sprd_pm_ops, sprd_suspend, sprd_resume);
+
+static struct platform_driver sprd_platform_driver = {
+ .probe = sprd_probe,
+ .remove = sprd_remove,
+ .driver = {
+ .name = "sprd_serial",
+ .of_match_table = of_match_ptr(serial_ids),
+ .pm = &sprd_pm_ops,
+ },
+};
+
+static int __init sprd_serial_init(void)
+{
+ int ret = 0;
+
+ ret = uart_register_driver(&sprd_uart_driver);
+ if (ret)
+ return ret;
+
+ ret = platform_driver_register(&sprd_platform_driver);
+ if (ret)
+ uart_unregister_driver(&sprd_uart_driver);
+
+ return ret;
+}
+
+static void __exit sprd_serial_exit(void)
+{
+ platform_driver_unregister(&sprd_platform_driver);
+ uart_unregister_driver(&sprd_uart_driver);
+}
+
+module_init(sprd_serial_init);
+module_exit(sprd_serial_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Spreadtrum SoC serial driver series");
diff --git a/include/uapi/linux/serial_core.h b/include/uapi/linux/serial_core.h
index c172180..7e6eb39 100644
--- a/include/uapi/linux/serial_core.h
+++ b/include/uapi/linux/serial_core.h
@@ -248,4 +248,7 @@
/* MESON */
#define PORT_MESON 109
+/* SPRD SERIAL */
+#define PORT_SPRD 110
+
#endif /* _UAPILINUX_SERIAL_CORE_H */
--
1.7.9.5
^ permalink raw reply related [flat|nested] 81+ messages in thread* Re: [PATCH v5 5/5] tty/serial: Add Spreadtrum sc9836-uart driver support
2015-01-16 10:00 ` Chunyan Zhang
@ 2015-01-16 10:26 ` Arnd Bergmann
-1 siblings, 0 replies; 81+ messages in thread
From: Arnd Bergmann @ 2015-01-16 10:26 UTC (permalink / raw)
To: Chunyan Zhang
Cc: gregkh, mark.rutland, gnomes, broonie, robh+dt, pawel.moll,
ijc+devicetree, galak, will.deacon, catalin.marinas, jslaby,
jason, heiko, florian.vaussard, andrew, rrichter, hytszk,
grant.likely, antonynpavlov, Joel.Schopp, Suravee.Suthikulpanit,
shawn.guo, lea.yan, jorge.ramirez-ortiz, lee.jones, orsonzhai,
geng.ren, zhizhou.zhang, lanqing.liu, zhang.lyra, wei.qiao,
devicetree, linux-arm-kernel, linux-kernel, linux-serial,
linux-api
On Friday 16 January 2015 18:00:11 Chunyan Zhang wrote:
> Add a full sc9836-uart driver for SC9836 SoC which is based on the
> spreadtrum sharkl64 platform.
> This driver also support earlycon.
> This patch also replaced the spaces between the macros and their
> values with the tabs in serial_core.h
>
> Signed-off-by: Chunyan Zhang <chunyan.zhang@spreadtrum.com>
> Signed-off-by: Orson Zhai <orson.zhai@spreadtrum.com>
> Originally-by: Lanqing Liu <lanqing.liu@spreadtrum.com>
>
I see nothing wrong with the patch contents, but a few things regarding
the submission process:
- The 'Signed-off-by' lines are in the wrong order. As the person
sending it, your S-o-b should be the last one in the list
- You have too many people on 'To'. Please send the patch only to
the person you expect to apply it, and put the other people that
may be interested on Cc. A lot of the people who got this mail
are probably not interested and you can drop them completely.
- Now that everything is reviewed, split the series according to
subsystem maintainers and send it separately: patches 1,2 and 5
should go to GregKH as one series, the rest should go to
'arm@kernel.org'.
- For some reason I did not get patch 4. Can you check if that
made it to the mailing list?
Feel free to add my 'Acked-by: Arnd Bergmann <arnd@arndb.de>' to
the patches you send to Greg.
Arnd
^ permalink raw reply [flat|nested] 81+ messages in thread
* [PATCH v5 5/5] tty/serial: Add Spreadtrum sc9836-uart driver support
@ 2015-01-16 10:26 ` Arnd Bergmann
0 siblings, 0 replies; 81+ messages in thread
From: Arnd Bergmann @ 2015-01-16 10:26 UTC (permalink / raw)
To: linux-arm-kernel
On Friday 16 January 2015 18:00:11 Chunyan Zhang wrote:
> Add a full sc9836-uart driver for SC9836 SoC which is based on the
> spreadtrum sharkl64 platform.
> This driver also support earlycon.
> This patch also replaced the spaces between the macros and their
> values with the tabs in serial_core.h
>
> Signed-off-by: Chunyan Zhang <chunyan.zhang@spreadtrum.com>
> Signed-off-by: Orson Zhai <orson.zhai@spreadtrum.com>
> Originally-by: Lanqing Liu <lanqing.liu@spreadtrum.com>
>
I see nothing wrong with the patch contents, but a few things regarding
the submission process:
- The 'Signed-off-by' lines are in the wrong order. As the person
sending it, your S-o-b should be the last one in the list
- You have too many people on 'To'. Please send the patch only to
the person you expect to apply it, and put the other people that
may be interested on Cc. A lot of the people who got this mail
are probably not interested and you can drop them completely.
- Now that everything is reviewed, split the series according to
subsystem maintainers and send it separately: patches 1,2 and 5
should go to GregKH as one series, the rest should go to
'arm at kernel.org'.
- For some reason I did not get patch 4. Can you check if that
made it to the mailing list?
Feel free to add my 'Acked-by: Arnd Bergmann <arnd@arndb.de>' to
the patches you send to Greg.
Arnd
^ permalink raw reply [flat|nested] 81+ messages in thread
* Re: [PATCH v5 5/5] tty/serial: Add Spreadtrum sc9836-uart driver support
@ 2015-01-16 11:02 ` Baruch Siach
0 siblings, 0 replies; 81+ messages in thread
From: Baruch Siach @ 2015-01-16 11:02 UTC (permalink / raw)
To: Chunyan Zhang
Cc: gregkh, mark.rutland, arnd, gnomes, broonie, robh+dt, pawel.moll,
ijc+devicetree, galak, will.deacon, catalin.marinas, jslaby,
jason, heiko, florian.vaussard, andrew, rrichter, hytszk,
grant.likely, antonynpavlov, Joel.Schopp, Suravee.Suthikulpanit,
shawn.guo, lea.yan, jorge.ramirez-ortiz, lee.jones, orsonzhai,
geng.ren, zhizhou.zhang, lanqing.liu, zhang.lyra, wei.qiao,
devicetree, linux-api, linux-kernel, linux-arm-kernel,
linux-serial
Hi Chunyan Zhang,
On Fri, Jan 16, 2015 at 06:00:11PM +0800, Chunyan Zhang wrote:
> + if (uart_handle_sysrq_char(port, ch))
> + continue;
You don't define SUPPORT_SYSRQ, so uart_handle_sysrq_char has no effect. See
include/linux/serial_core.h.
baruch
--
http://baruch.siach.name/blog/ ~. .~ Tk Open Systems
=}------------------------------------------------ooO--U--Ooo------------{=
- baruch@tkos.co.il - tel: +972.2.679.5364, http://www.tkos.co.il -
^ permalink raw reply [flat|nested] 81+ messages in thread* [PATCH v5 5/5] tty/serial: Add Spreadtrum sc9836-uart driver support
@ 2015-01-16 11:02 ` Baruch Siach
0 siblings, 0 replies; 81+ messages in thread
From: Baruch Siach @ 2015-01-16 11:02 UTC (permalink / raw)
To: linux-arm-kernel
Hi Chunyan Zhang,
On Fri, Jan 16, 2015 at 06:00:11PM +0800, Chunyan Zhang wrote:
> + if (uart_handle_sysrq_char(port, ch))
> + continue;
You don't define SUPPORT_SYSRQ, so uart_handle_sysrq_char has no effect. See
include/linux/serial_core.h.
baruch
--
http://baruch.siach.name/blog/ ~. .~ Tk Open Systems
=}------------------------------------------------ooO--U--Ooo------------{=
- baruch at tkos.co.il - tel: +972.2.679.5364, http://www.tkos.co.il -
^ permalink raw reply [flat|nested] 81+ messages in thread* Re: [PATCH v5 5/5] tty/serial: Add Spreadtrum sc9836-uart driver support
@ 2015-01-16 11:02 ` Baruch Siach
0 siblings, 0 replies; 81+ messages in thread
From: Baruch Siach @ 2015-01-16 11:02 UTC (permalink / raw)
To: Chunyan Zhang
Cc: gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r,
mark.rutland-5wv7dgnIgG8, arnd-r2nGTMty4D4,
gnomes-qBU/x9rampVanCEyBjwyrvXRex20P6io,
broonie-DgEjT+Ai2ygdnm+yROfE0A, robh+dt-DgEjT+Ai2ygdnm+yROfE0A,
pawel.moll-5wv7dgnIgG8, ijc+devicetree-KcIKpvwj1kUDXYZnReoRVg,
galak-sgV2jX0FEOL9JmXXK+q4OQ, will.deacon-5wv7dgnIgG8,
catalin.marinas-5wv7dgnIgG8, jslaby-AlSwsSmVLrQ,
jason-NLaQJdtUoK4Be96aLqz0jA, heiko-4mtYJXux2i+zQB+pC5nmwQ,
florian.vaussard-p8DiymsW2f8, andrew-g2DYL2Zd6BY,
rrichter-YGCgFSpz5w/QT0dZR+AlfA, hytszk-Re5JQEeQqe8AvxtiuMwx3w,
grant.likely-QSEj5FYQhm4dnm+yROfE0A,
antonynpavlov-Re5JQEeQqe8AvxtiuMwx3w, Joel.Schopp-5C7GfCeVMHo,
Suravee.Suthikulpanit-5C7GfCeVMHo,
shawn.guo-QSEj5FYQhm4dnm+yROfE0A, lea.yan-QSEj5FYQhm4dnm+yROfE0A,
jorge.ramirez-ortiz-QSEj5FYQhm4dnm+yROfE0A,
lee.jones-QSEj5FYQhm4dnm+yROfE0A,
orsonzhai-Re5JQEeQqe8AvxtiuMwx3w,
geng.ren-lxIno14LUO0EEoCn2XhGlw,
zhizhou.zhang-lxIno14LUO0EEoCn2XhGlw,
lanqing.liu-lxIno14LUO0EEoCn2XhGlw,
zhang.lyra-Re5JQEeQqe8AvxtiuMwx3w,
wei.qiao-lxIno14LUO0EEoCn2XhGlw,
devicetree-u79uwXL29TY76Z2rM5mHXA,
linux-api-u79uwXL29TY76Z2rM5mHXA,
linux-kernel-u79uwXL29TY76Z2rM5mHXA,
linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r,
linux-serial-u79uwXL29TY
Hi Chunyan Zhang,
On Fri, Jan 16, 2015 at 06:00:11PM +0800, Chunyan Zhang wrote:
> + if (uart_handle_sysrq_char(port, ch))
> + continue;
You don't define SUPPORT_SYSRQ, so uart_handle_sysrq_char has no effect. See
include/linux/serial_core.h.
baruch
--
http://baruch.siach.name/blog/ ~. .~ Tk Open Systems
=}------------------------------------------------ooO--U--Ooo------------{=
- baruch-NswTu9S1W3P6gbPvEgmw2w@public.gmane.org - tel: +972.2.679.5364, http://www.tkos.co.il -
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
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More majordomo info at http://vger.kernel.org/majordomo-info.html
^ permalink raw reply [flat|nested] 81+ messages in thread
* Re: [PATCH v5 5/5] tty/serial: Add Spreadtrum sc9836-uart driver support
@ 2015-01-16 15:20 ` Peter Hurley
0 siblings, 0 replies; 81+ messages in thread
From: Peter Hurley @ 2015-01-16 15:20 UTC (permalink / raw)
To: Chunyan Zhang
Cc: gregkh, mark.rutland, arnd, gnomes, broonie, robh+dt, pawel.moll,
ijc+devicetree, galak, will.deacon, catalin.marinas, jslaby,
jason, heiko, florian.vaussard, andrew, rrichter, hytszk,
grant.likely, antonynpavlov, Joel.Schopp, Suravee.Suthikulpanit,
shawn.guo, lea.yan, jorge.ramirez-ortiz, lee.jones, orsonzhai,
geng.ren, zhizhou.zhang, lanqing.liu, zhang.lyra, wei.qiao,
devicetree, linux-api, linux-kernel, linux-arm-kernel,
linux-serial
On 01/16/2015 05:00 AM, Chunyan Zhang wrote:
> Add a full sc9836-uart driver for SC9836 SoC which is based on the
> spreadtrum sharkl64 platform.
> This driver also support earlycon.
> This patch also replaced the spaces between the macros and their
> values with the tabs in serial_core.h
The locking doesn't look correct. Specific notations below.
> Signed-off-by: Chunyan Zhang <chunyan.zhang@spreadtrum.com>
> Signed-off-by: Orson Zhai <orson.zhai@spreadtrum.com>
> Originally-by: Lanqing Liu <lanqing.liu@spreadtrum.com>
> ---
> drivers/tty/serial/Kconfig | 18 +
> drivers/tty/serial/Makefile | 1 +
> drivers/tty/serial/sprd_serial.c | 772 ++++++++++++++++++++++++++++++++++++++
> include/uapi/linux/serial_core.h | 3 +
> 4 files changed, 794 insertions(+)
> create mode 100644 drivers/tty/serial/sprd_serial.c
>
> diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
> index c79b43c..969d3cd 100644
> --- a/drivers/tty/serial/Kconfig
> +++ b/drivers/tty/serial/Kconfig
> @@ -1577,6 +1577,24 @@ config SERIAL_MEN_Z135
> This driver can also be build as a module. If so, the module will be called
> men_z135_uart.ko
>
> +config SERIAL_SPRD
> + tristate "Support for SPRD serial"
> + depends on ARCH_SPRD
> + select SERIAL_CORE
> + help
> + This enables the driver for the Spreadtrum's serial.
> +
> +config SERIAL_SPRD_CONSOLE
> + bool "SPRD UART console support"
> + depends on SERIAL_SPRD=y
> + select SERIAL_CORE_CONSOLE
> + select SERIAL_EARLYCON
> + help
> + Support for early debug console using Spreadtrum's serial. This enables
> + the console before standard serial driver is probed. This is enabled
> + with "earlycon" on the kernel command line. The console is
> + enabled when early_param is processed.
> +
> endmenu
>
> config SERIAL_MCTRL_GPIO
> diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile
> index 9a548ac..4801aca 100644
> --- a/drivers/tty/serial/Makefile
> +++ b/drivers/tty/serial/Makefile
> @@ -93,6 +93,7 @@ obj-$(CONFIG_SERIAL_ARC) += arc_uart.o
> obj-$(CONFIG_SERIAL_RP2) += rp2.o
> obj-$(CONFIG_SERIAL_FSL_LPUART) += fsl_lpuart.o
> obj-$(CONFIG_SERIAL_MEN_Z135) += men_z135_uart.o
> +obj-$(CONFIG_SERIAL_SPRD) += sprd_serial.o
>
> # GPIOLIB helpers for modem control lines
> obj-$(CONFIG_SERIAL_MCTRL_GPIO) += serial_mctrl_gpio.o
> diff --git a/drivers/tty/serial/sprd_serial.c b/drivers/tty/serial/sprd_serial.c
> new file mode 100644
> index 0000000..81839e4
> --- /dev/null
> +++ b/drivers/tty/serial/sprd_serial.c
> @@ -0,0 +1,772 @@
> +/*
> + * Copyright (C) 2012 Spreadtrum Communications Inc.
> + *
> + * This software is licensed under the terms of the GNU General Public
> + * License version 2, as published by the Free Software Foundation, and
> + * may be copied, distributed, and modified under those terms.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/console.h>
> +#include <linux/delay.h>
> +#include <linux/io.h>
> +#include <linux/ioport.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/serial_core.h>
> +#include <linux/serial.h>
> +#include <linux/slab.h>
> +#include <linux/tty.h>
> +#include <linux/tty_flip.h>
> +
> +/* device name */
> +#define UART_NR_MAX 8
> +#define SPRD_TTY_NAME "ttySPX"
> +#define SPRD_FIFO_SIZE 128
> +#define SPRD_DEF_RATE 26000000
> +#define SPRD_TIMEOUT 2048
> +
> +/* the offset of serial registers and BITs for them */
> +/* data registers */
> +#define SPRD_TXD 0x0000
> +#define SPRD_RXD 0x0004
> +
> +/* line status register and its BITs */
> +#define SPRD_LSR 0x0008
> +#define SPRD_LSR_OE BIT(4)
> +#define SPRD_LSR_FE BIT(3)
> +#define SPRD_LSR_PE BIT(2)
> +#define SPRD_LSR_BI BIT(7)
> +#define SPRD_LSR_TX_OVER BIT(15)
> +
> +/* data number in TX and RX fifo */
> +#define SPRD_STS1 0x000C
> +
> +/* interrupt enable register and its BITs */
> +#define SPRD_IEN 0x0010
> +#define SPRD_IEN_RX_FULL BIT(0)
> +#define SPRD_IEN_TX_EMPTY BIT(1)
> +#define SPRD_IEN_BREAK_DETECT BIT(7)
> +#define SPRD_IEN_TIMEOUT BIT(13)
> +
> +/* interrupt clear register */
> +#define SPRD_ICLR 0x0014
> +
> +/* line control register */
> +#define SPRD_LCR 0x0018
> +#define SPRD_LCR_STOP_1BIT 0x10
> +#define SPRD_LCR_STOP_2BIT 0x30
> +#define SPRD_LCR_DATA_LEN (BIT(2) | BIT(3))
> +#define SPRD_LCR_DATA_LEN5 0x0
> +#define SPRD_LCR_DATA_LEN6 0x4
> +#define SPRD_LCR_DATA_LEN7 0x8
> +#define SPRD_LCR_DATA_LEN8 0xc
> +#define SPRD_LCR_PARITY (BIT(0) | BIT(1))
> +#define SPRD_LCR_PARITY_EN 0x2
> +#define SPRD_LCR_EVEN_PAR 0x0
> +#define SPRD_LCR_ODD_PAR 0x1
> +
> +/* control register 1 */
> +#define SPRD_CTL1 0x001C
> +#define RX_HW_FLOW_CTL_THLD BIT(6)
> +#define RX_HW_FLOW_CTL_EN BIT(7)
> +#define TX_HW_FLOW_CTL_EN BIT(8)
> +
> +/* fifo threshold register */
> +#define SPRD_CTL2 0x0020
> +#define THLD_TX_EMPTY 0x40
> +#define THLD_RX_FULL 0x40
> +
> +/* config baud rate register */
> +#define SPRD_CLKD0 0x0024
> +#define SPRD_CLKD1 0x0028
> +
> +/* interrupt mask status register */
> +#define SPRD_IMSR 0x002C
> +#define SPRD_IMSR_RX_FIFO_FULL BIT(0)
> +#define SPRD_IMSR_TX_FIFO_EMPTY BIT(1)
> +#define SPRD_IMSR_BREAK_DETECT BIT(7)
> +#define SPRD_IMSR_TIMEOUT BIT(13)
> +
> +struct reg_backup {
> + uint32_t ien;
> + uint32_t ctrl0;
> + uint32_t ctrl1;
> + uint32_t ctrl2;
> + uint32_t clkd0;
> + uint32_t clkd1;
> + uint32_t dspwait;
> +};
> +
> +struct sprd_uart_port {
> + struct uart_port port;
> + struct reg_backup reg_bak;
> + char name[16];
> +};
> +
> +static struct sprd_uart_port *sprd_port[UART_NR_MAX] = { NULL };
> +
> +static inline unsigned int serial_in(struct uart_port *port, int offset)
> +{
> + return readl_relaxed(port->membase + offset);
> +}
> +
> +static inline void serial_out(struct uart_port *port, int offset, int value)
> +{
> + writel_relaxed(value, port->membase + offset);
> +}
> +
> +static unsigned int sprd_tx_empty(struct uart_port *port)
> +{
> + if (serial_in(port, SPRD_STS1) & 0xff00)
> + return 0;
> + else
> + return TIOCSER_TEMT;
> +}
> +
> +static unsigned int sprd_get_mctrl(struct uart_port *port)
> +{
> + return TIOCM_DSR | TIOCM_CTS;
> +}
> +
> +static void sprd_set_mctrl(struct uart_port *port, unsigned int mctrl)
> +{
> + /* nothing to do */
> +}
> +
> +static void sprd_stop_tx(struct uart_port *port)
> +{
> + unsigned int ien, iclr;
> +
> + iclr = serial_in(port, SPRD_ICLR);
> + ien = serial_in(port, SPRD_IEN);
> +
> + iclr |= SPRD_IEN_TX_EMPTY;
> + ien &= ~SPRD_IEN_TX_EMPTY;
> +
> + serial_out(port, SPRD_ICLR, iclr);
> + serial_out(port, SPRD_IEN, ien);
> +}
> +
> +static void sprd_start_tx(struct uart_port *port)
> +{
> + unsigned int ien;
> +
> + ien = serial_in(port, SPRD_IEN);
> + if (!(ien & SPRD_IEN_TX_EMPTY)) {
> + ien |= SPRD_IEN_TX_EMPTY;
> + serial_out(port, SPRD_IEN, ien);
> + }
> +}
> +
> +static void sprd_stop_rx(struct uart_port *port)
> +{
> + unsigned int ien, iclr;
> +
> + iclr = serial_in(port, SPRD_ICLR);
> + ien = serial_in(port, SPRD_IEN);
> +
> + ien &= ~(SPRD_IEN_RX_FULL | SPRD_IEN_BREAK_DETECT);
> + iclr |= SPRD_IEN_RX_FULL | SPRD_IEN_BREAK_DETECT;
> +
> + serial_out(port, SPRD_IEN, ien);
> + serial_out(port, SPRD_ICLR, iclr);
> +}
> +
> +/* The Sprd serial does not support this function. */
> +static void sprd_break_ctl(struct uart_port *port, int break_state)
> +{
> + /* nothing to do */
> +}
> +
> +static inline int handle_lsr_errors(struct uart_port *port,
> + unsigned int *flag,
> + unsigned int *lsr)
> +{
> + int ret = 0;
> +
> + /* statistics */
> + if (*lsr & SPRD_LSR_BI) {
> + *lsr &= ~(SPRD_LSR_FE | SPRD_LSR_PE);
> + port->icount.brk++;
> + ret = uart_handle_break(port);
> + if (ret)
> + return ret;
> + } else if (*lsr & SPRD_LSR_PE)
> + port->icount.parity++;
> + else if (*lsr & SPRD_LSR_FE)
> + port->icount.frame++;
> + if (*lsr & SPRD_LSR_OE)
> + port->icount.overrun++;
> +
> + /* mask off conditions which should be ignored */
> + *lsr &= port->read_status_mask;
> + if (*lsr & SPRD_LSR_BI)
> + *flag = TTY_BREAK;
> + else if (*lsr & SPRD_LSR_PE)
> + *flag = TTY_PARITY;
> + else if (*lsr & SPRD_LSR_FE)
> + *flag = TTY_FRAME;
> +
> + return ret;
> +}
> +
> +static inline void sprd_rx(int irq, void *dev_id)
> +{
> + struct uart_port *port = dev_id;
> + struct tty_port *tty = &port->state->port;
> + unsigned int ch, flag, lsr, max_count = SPRD_TIMEOUT;
> +
> + while ((serial_in(port, SPRD_STS1) & 0x00ff) && max_count--) {
> + lsr = serial_in(port, SPRD_LSR);
> + ch = serial_in(port, SPRD_RXD);
> + flag = TTY_NORMAL;
> + port->icount.rx++;
> +
> + if (lsr & (SPRD_LSR_BI | SPRD_LSR_PE
> + | SPRD_LSR_FE | SPRD_LSR_OE))
> + if (handle_lsr_errors(port, &lsr, &flag))
> + continue;
> + if (uart_handle_sysrq_char(port, ch))
> + continue;
> +
> + uart_insert_char(port, lsr, SPRD_LSR_OE, ch, flag);
> + }
> +
> + tty_flip_buffer_push(tty);
> +}
> +
> +static inline void sprd_tx(int irq, void *dev_id)
> +{
> + struct uart_port *port = dev_id;
> + struct circ_buf *xmit = &port->state->xmit;
> + int count;
> +
> + if (port->x_char) {
> + serial_out(port, SPRD_TXD, port->x_char);
> + port->icount.tx++;
> + port->x_char = 0;
> + return;
> + }
> +
> + if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
> + sprd_stop_tx(port);
> + return;
> + }
> +
> + count = THLD_TX_EMPTY;
> + do {
> + serial_out(port, SPRD_TXD, xmit->buf[xmit->tail]);
> + xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
> + port->icount.tx++;
> + if (uart_circ_empty(xmit))
> + break;
> + } while (--count > 0);
> +
> + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
> + uart_write_wakeup(port);
> +
> + if (uart_circ_empty(xmit))
> + sprd_stop_tx(port);
> +}
> +
> +/* this handles the interrupt from one port */
> +static irqreturn_t sprd_handle_irq(int irq, void *dev_id)
> +{
> + struct uart_port *port = (struct uart_port *)dev_id;
> + unsigned int ims;
Why does your isr not have to take port->lock ?
> + ims = serial_in(port, SPRD_IMSR);
> +
> + if (!ims)
> + return IRQ_NONE;
> +
> + serial_out(port, SPRD_ICLR, ~0);
> +
> + if (ims & (SPRD_IMSR_RX_FIFO_FULL |
> + SPRD_IMSR_BREAK_DETECT | SPRD_IMSR_TIMEOUT))
> + sprd_rx(irq, port);
> +
> + if (ims & SPRD_IMSR_TX_FIFO_EMPTY)
> + sprd_tx(irq, port);
> +
> + return IRQ_HANDLED;
> +}
> +
> +static int sprd_startup(struct uart_port *port)
> +{
> + int ret = 0;
> + unsigned int ien, ctrl1;
> + unsigned int timeout;
> + struct sprd_uart_port *sp;
> +
> + serial_out(port, SPRD_CTL2, ((THLD_TX_EMPTY << 8) | THLD_RX_FULL));
> +
> + /* clear rx fifo */
> + timeout = SPRD_TIMEOUT;
> + while (timeout-- && serial_in(port, SPRD_STS1) & 0x00ff)
> + serial_in(port, SPRD_RXD);
> +
> + /* clear tx fifo */
> + timeout = SPRD_TIMEOUT;
> + while (timeout-- && serial_in(port, SPRD_STS1) & 0xff00)
> + cpu_relax();
> +
> + /* clear interrupt */
> + serial_out(port, SPRD_IEN, 0x0);
> + serial_out(port, SPRD_ICLR, ~0);
> +
> + /* allocate irq */
> + sp = container_of(port, struct sprd_uart_port, port);
> + snprintf(sp->name, sizeof(sp->name), "sprd_serial%d", port->line);
> + ret = devm_request_irq(port->dev, port->irq, sprd_handle_irq,
> + IRQF_SHARED, sp->name, port);
> + if (ret) {
> + dev_err(port->dev, "fail to request serial irq %d, ret=%d\n",
> + port->irq, ret);
> + return ret;
> + }
> + ctrl1 = serial_in(port, SPRD_CTL1);
> + ctrl1 |= 0x3e00 | THLD_RX_FULL;
> + serial_out(port, SPRD_CTL1, ctrl1);
> +
> + /* enable interrupt */
> + spin_lock(&port->lock);
> + ien = serial_in(port, SPRD_IEN);
> + ien |= SPRD_IEN_RX_FULL | SPRD_IEN_BREAK_DETECT | SPRD_IEN_TIMEOUT;
> + serial_out(port, SPRD_IEN, ien);
> + spin_unlock(&port->lock);
> +
> + return 0;
> +}
> +
> +static void sprd_shutdown(struct uart_port *port)
> +{
> + serial_out(port, SPRD_IEN, 0x0);
> + serial_out(port, SPRD_ICLR, ~0);
> + devm_free_irq(port->dev, port->irq, port);
> +}
> +
> +static void sprd_set_termios(struct uart_port *port,
> + struct ktermios *termios,
> + struct ktermios *old)
> +{
> + unsigned int baud, quot;
> + unsigned int lcr, fc;
> +
> + /* ask the core to calculate the divisor for us */
> + baud = uart_get_baud_rate(port, termios, old, 1200, 3000000);
> +
> + quot = (unsigned int)((port->uartclk + baud / 2) / baud);
> +
> + /* set data length */
> + lcr = serial_in(port, SPRD_LCR);
> + lcr &= ~SPRD_LCR_DATA_LEN;
> + switch (termios->c_cflag & CSIZE) {
> + case CS5:
> + lcr |= SPRD_LCR_DATA_LEN5;
> + break;
> + case CS6:
> + lcr |= SPRD_LCR_DATA_LEN6;
> + break;
> + case CS7:
> + lcr |= SPRD_LCR_DATA_LEN7;
> + break;
> + case CS8:
> + default:
> + lcr |= SPRD_LCR_DATA_LEN8;
> + break;
> + }
> +
> + /* calculate stop bits */
> + lcr &= ~(SPRD_LCR_STOP_1BIT | SPRD_LCR_STOP_2BIT);
> + if (termios->c_cflag & CSTOPB)
> + lcr |= SPRD_LCR_STOP_2BIT;
> + else
> + lcr |= SPRD_LCR_STOP_1BIT;
> +
> + /* calculate parity */
> + lcr &= ~SPRD_LCR_PARITY;
> + termios->c_cflag &= ~CMSPAR; /* no support mark/space */
> + if (termios->c_cflag & PARENB) {
> + lcr |= SPRD_LCR_PARITY_EN;
> + if (termios->c_cflag & PARODD)
> + lcr |= SPRD_LCR_ODD_PAR;
> + else
> + lcr |= SPRD_LCR_EVEN_PAR;
> + }
> +
> + /* change the port state. */
^^^^^^^^^^^^^^^^^^^^^^
This means you should be taking the port->lock here... (and disabling
local interrupts if your isr takes the port->lock)
> + /* update the per-port timeout */
> + uart_update_timeout(port, termios->c_cflag, baud);
> +
> + port->read_status_mask = SPRD_LSR_OE;
> + if (termios->c_iflag & INPCK)
> + port->read_status_mask |= SPRD_LSR_FE | SPRD_LSR_PE;
> + if (termios->c_iflag & (BRKINT | PARMRK))
> + port->read_status_mask |= SPRD_LSR_BI;
> +
> + /* characters to ignore */
> + port->ignore_status_mask = 0;
> + if (termios->c_iflag & IGNPAR)
> + port->ignore_status_mask |= SPRD_LSR_PE | SPRD_LSR_FE;
> + if (termios->c_iflag & IGNBRK) {
> + port->ignore_status_mask |= SPRD_LSR_BI;
> + /*
> + * If we're ignoring parity and break indicators,
> + * ignore overruns too (for real raw support).
> + */
> + if (termios->c_iflag & IGNPAR)
> + port->ignore_status_mask |= SPRD_LSR_OE;
> + }
> +
> + /* flow control */
> + fc = serial_in(port, SPRD_CTL1);
> + fc &= ~(RX_HW_FLOW_CTL_THLD | RX_HW_FLOW_CTL_EN | TX_HW_FLOW_CTL_EN);
> + if (termios->c_cflag & CRTSCTS) {
> + fc |= RX_HW_FLOW_CTL_THLD;
> + fc |= RX_HW_FLOW_CTL_EN;
> + fc |= TX_HW_FLOW_CTL_EN;
> + }
> +
> + /* clock divider bit0~bit15 */
> + serial_out(port, SPRD_CLKD0, quot & 0xffff);
> +
> + /* clock divider bit16~bit20 */
> + serial_out(port, SPRD_CLKD1, (quot & 0x1f0000) >> 16);
> + serial_out(port, SPRD_LCR, lcr);
> + fc |= 0x3e00 | THLD_RX_FULL;
> + serial_out(port, SPRD_CTL1, fc);
and dropping it here.
> + /* Don't rewrite B0 */
> + if (tty_termios_baud_rate(termios))
> + tty_termios_encode_baud_rate(termios, baud, baud);
> +}
> +
> +static const char *sprd_type(struct uart_port *port)
> +{
> + return "SPX";
> +}
> +
> +static void sprd_release_port(struct uart_port *port)
> +{
> + /* nothing to do */
> +}
> +
> +static int sprd_request_port(struct uart_port *port)
> +{
> + return 0;
> +}
> +
> +static void sprd_config_port(struct uart_port *port, int flags)
> +{
> + if (flags & UART_CONFIG_TYPE)
> + port->type = PORT_SPRD;
> +}
> +
> +static int sprd_verify_port(struct uart_port *port,
> + struct serial_struct *ser)
> +{
> + if (ser->type != PORT_SPRD)
> + return -EINVAL;
> + if (port->irq != ser->irq)
> + return -EINVAL;
> + return 0;
> +}
> +
> +static struct uart_ops serial_sprd_ops = {
> + .tx_empty = sprd_tx_empty,
> + .get_mctrl = sprd_get_mctrl,
> + .set_mctrl = sprd_set_mctrl,
> + .stop_tx = sprd_stop_tx,
> + .start_tx = sprd_start_tx,
> + .stop_rx = sprd_stop_rx,
> + .break_ctl = sprd_break_ctl,
> + .startup = sprd_startup,
> + .shutdown = sprd_shutdown,
> + .set_termios = sprd_set_termios,
> + .type = sprd_type,
> + .release_port = sprd_release_port,
> + .request_port = sprd_request_port,
> + .config_port = sprd_config_port,
> + .verify_port = sprd_verify_port,
> +};
> +
> +#ifdef CONFIG_SERIAL_SPRD_CONSOLE
> +static inline void wait_for_xmitr(struct uart_port *port)
> +{
> + unsigned int status, tmout = 10000;
> +
> + /* wait up to 10ms for the character(s) to be sent */
> + do {
> + status = serial_in(port, SPRD_STS1);
> + if (--tmout == 0)
> + break;
> + udelay(1);
> + } while (status & 0xff00);
> +}
> +
> +static void sprd_console_putchar(struct uart_port *port, int ch)
> +{
> + wait_for_xmitr(port);
> + serial_out(port, SPRD_TXD, ch);
> +}
> +
> +static void sprd_console_write(struct console *co, const char *s,
> + unsigned int count)
> +{
> + struct uart_port *port = &sprd_port[co->index]->port;
> + int ien;
> + int locked = 1;
> +
> + if (oops_in_progress)
> + locked = spin_trylock(&port->lock);
> + else
> + spin_lock(&port->lock);
If you do need to take the port->lock in your isr, then you need to
disable local irq here.
> + /* save the IEN then disable the interrupts */
> + ien = serial_in(port, SPRD_IEN);
> + serial_out(port, SPRD_IEN, 0x0);
> +
> + uart_console_write(port, s, count, sprd_console_putchar);
> +
> + /* wait for transmitter to become empty and restore the IEN */
> + wait_for_xmitr(port);
> + serial_out(port, SPRD_IEN, ien);
> + if (locked)
> + spin_unlock(&port->lock);
> +}
> +
> +static int __init sprd_console_setup(struct console *co, char *options)
> +{
> + struct uart_port *port;
> + int baud = 115200;
> + int bits = 8;
> + int parity = 'n';
> + int flow = 'n';
> +
> + if (co->index >= UART_NR_MAX || co->index < 0)
> + co->index = 0;
> +
> + port = &sprd_port[co->index]->port;
> + if (port == NULL) {
> + pr_info("serial port %d not yet initialized\n", co->index);
> + return -ENODEV;
> + }
> + if (options)
> + uart_parse_options(options, &baud, &parity, &bits, &flow);
> +
> + return uart_set_options(port, co, baud, parity, bits, flow);
> +}
> +
> +static struct uart_driver sprd_uart_driver;
> +static struct console sprd_console = {
> + .name = SPRD_TTY_NAME,
> + .write = sprd_console_write,
> + .device = uart_console_device,
> + .setup = sprd_console_setup,
> + .flags = CON_PRINTBUFFER,
> + .index = -1,
> + .data = &sprd_uart_driver,
> +};
> +
> +#define SPRD_CONSOLE (&sprd_console)
> +
> +/* Support for earlycon */
> +static void sprd_putc(struct uart_port *port, int c)
> +{
> + unsigned int timeout = SPRD_TIMEOUT;
> +
> + while (timeout-- &&
> + !(readl(port->membase + SPRD_LSR) & SPRD_LSR_TX_OVER))
> + cpu_relax();
> +
> + writeb(c, port->membase + SPRD_TXD);
> +}
> +
> +static void sprd_early_write(struct console *con, const char *s,
> + unsigned n)
> +{
> + struct earlycon_device *dev = con->data;
> +
> + uart_console_write(&dev->port, s, n, sprd_putc);
> +}
> +
> +static int __init sprd_early_console_setup(
> + struct earlycon_device *device,
> + const char *opt)
> +{
> + if (!device->port.membase)
> + return -ENODEV;
> +
> + device->con->write = sprd_early_write;
> + return 0;
> +}
> +
> +EARLYCON_DECLARE(sprd_serial, sprd_early_console_setup);
> +OF_EARLYCON_DECLARE(sprd_serial, "sprd,sc9836-uart",
> + sprd_early_console_setup);
> +
> +#else /* !CONFIG_SERIAL_SPRD_CONSOLE */
> +#define SPRD_CONSOLE NULL
> +#endif
> +
> +static struct uart_driver sprd_uart_driver = {
> + .owner = THIS_MODULE,
> + .driver_name = "sprd_serial",
> + .dev_name = SPRD_TTY_NAME,
> + .major = 0,
> + .minor = 0,
> + .nr = UART_NR_MAX,
> + .cons = SPRD_CONSOLE,
> +};
> +
> +static int sprd_probe(struct platform_device *pdev)
> +{
> + struct resource *res;
> + struct device_node *np = pdev->dev.of_node;
> + struct uart_port *up;
> + struct clk *clk;
> + int irq;
> +
> + if (np)
> + pdev->id = of_alias_get_id(np, "serial");
> +
> + if (pdev->id < 0 || pdev->id >= UART_NR_MAX) {
> + dev_err(&pdev->dev, "does not support id %d\n", pdev->id);
> + return -ENXIO;
> + }
> +
> + sprd_port[pdev->id] = devm_kzalloc(&pdev->dev,
> + sizeof(*sprd_port[pdev->id]), GFP_KERNEL);
> + if (!sprd_port[pdev->id])
> + return -ENOMEM;
> +
> + up = &sprd_port[pdev->id]->port;
> + up->dev = &pdev->dev;
> + up->line = pdev->id;
> + up->type = PORT_SPRD;
> + up->iotype = SERIAL_IO_PORT;
> + up->uartclk = SPRD_DEF_RATE;
> + up->fifosize = SPRD_FIFO_SIZE;
> + up->ops = &serial_sprd_ops;
> + up->flags = ASYNC_BOOT_AUTOCONF;
> +
> + clk = devm_clk_get(&pdev->dev, NULL);
> + if (!IS_ERR(clk))
> + up->uartclk = clk_get_rate(clk);
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + if (!res) {
> + dev_err(&pdev->dev, "not provide mem resource\n");
> + return -ENODEV;
> + }
> + up->mapbase = res->start;
> + up->membase = devm_ioremap_resource(&pdev->dev, res);
> + if (IS_ERR(up->membase))
> + return PTR_ERR(up->membase);
> +
> + irq = platform_get_irq(pdev, 0);
> + if (irq < 0) {
> + dev_err(&pdev->dev, "not provide irq resource\n");
> + return -ENODEV;
> + }
> + up->irq = irq;
> +
> + platform_set_drvdata(pdev, up);
> +
> + return uart_add_one_port(&sprd_uart_driver, up);
> +}
> +
> +static int sprd_remove(struct platform_device *dev)
> +{
> + struct uart_port *up = platform_get_drvdata(dev);
> +
> + return uart_remove_one_port(&sprd_uart_driver, up);
> +}
> +
> +static int sprd_suspend(struct device *dev)
> +{
> + int id = to_platform_device(dev)->id;
> + struct uart_port *port = &sprd_port[id]->port;
> + struct reg_backup *reg_bak = &sprd_port[id]->reg_bak;
> +
> + reg_bak->ien = serial_in(port, SPRD_IEN);
> + reg_bak->ctrl0 = serial_in(port, SPRD_LCR);
> + reg_bak->ctrl1 = serial_in(port, SPRD_CTL1);
> + reg_bak->ctrl2 = serial_in(port, SPRD_CTL2);
> + reg_bak->clkd0 = serial_in(port, SPRD_CLKD0);
> + reg_bak->clkd1 = serial_in(port, SPRD_CLKD1);
Why are you saving and restoring these register states
across suspend/resume?
The serial core calls your set_termios() handler upon
resume (either for the console or if a tty is open)
so you should be reprogramming the hardware there
based on the termios settings.
Regards,
Peter Hurley
> +
> + uart_suspend_port(&sprd_uart_driver, port);
> +
> + return 0;
> +}
> +
> +static int sprd_resume(struct device *dev)
> +{
> + int id = to_platform_device(dev)->id;
> + struct uart_port *port = &sprd_port[id]->port;
> + struct reg_backup *reg_bak = &sprd_port[id]->reg_bak;
> +
> + serial_out(port, SPRD_LCR, reg_bak->ctrl0);
> + serial_out(port, SPRD_CTL1, reg_bak->ctrl1);
> + serial_out(port, SPRD_CTL2, reg_bak->ctrl2);
> + serial_out(port, SPRD_CLKD0, reg_bak->clkd0);
> + serial_out(port, SPRD_CLKD1, reg_bak->clkd1);
> + serial_out(port, SPRD_IEN, reg_bak->ien);
> +
> + uart_resume_port(&sprd_uart_driver, port);
> +
> + return 0;
> +}
> +
> +static const struct of_device_id serial_ids[] = {
> + {.compatible = "sprd,sc9836-uart",},
> + {}
> +};
> +
> +static SIMPLE_DEV_PM_OPS(sprd_pm_ops, sprd_suspend, sprd_resume);
> +
> +static struct platform_driver sprd_platform_driver = {
> + .probe = sprd_probe,
> + .remove = sprd_remove,
> + .driver = {
> + .name = "sprd_serial",
> + .of_match_table = of_match_ptr(serial_ids),
> + .pm = &sprd_pm_ops,
> + },
> +};
> +
> +static int __init sprd_serial_init(void)
> +{
> + int ret = 0;
> +
> + ret = uart_register_driver(&sprd_uart_driver);
> + if (ret)
> + return ret;
> +
> + ret = platform_driver_register(&sprd_platform_driver);
> + if (ret)
> + uart_unregister_driver(&sprd_uart_driver);
> +
> + return ret;
> +}
> +
> +static void __exit sprd_serial_exit(void)
> +{
> + platform_driver_unregister(&sprd_platform_driver);
> + uart_unregister_driver(&sprd_uart_driver);
> +}
> +
> +module_init(sprd_serial_init);
> +module_exit(sprd_serial_exit);
> +
> +MODULE_LICENSE("GPL v2");
> +MODULE_DESCRIPTION("Spreadtrum SoC serial driver series");
> diff --git a/include/uapi/linux/serial_core.h b/include/uapi/linux/serial_core.h
> index c172180..7e6eb39 100644
> --- a/include/uapi/linux/serial_core.h
> +++ b/include/uapi/linux/serial_core.h
> @@ -248,4 +248,7 @@
> /* MESON */
> #define PORT_MESON 109
>
> +/* SPRD SERIAL */
> +#define PORT_SPRD 110
> +
> #endif /* _UAPILINUX_SERIAL_CORE_H */
>
^ permalink raw reply [flat|nested] 81+ messages in thread* [PATCH v5 5/5] tty/serial: Add Spreadtrum sc9836-uart driver support
@ 2015-01-16 15:20 ` Peter Hurley
0 siblings, 0 replies; 81+ messages in thread
From: Peter Hurley @ 2015-01-16 15:20 UTC (permalink / raw)
To: linux-arm-kernel
On 01/16/2015 05:00 AM, Chunyan Zhang wrote:
> Add a full sc9836-uart driver for SC9836 SoC which is based on the
> spreadtrum sharkl64 platform.
> This driver also support earlycon.
> This patch also replaced the spaces between the macros and their
> values with the tabs in serial_core.h
The locking doesn't look correct. Specific notations below.
> Signed-off-by: Chunyan Zhang <chunyan.zhang@spreadtrum.com>
> Signed-off-by: Orson Zhai <orson.zhai@spreadtrum.com>
> Originally-by: Lanqing Liu <lanqing.liu@spreadtrum.com>
> ---
> drivers/tty/serial/Kconfig | 18 +
> drivers/tty/serial/Makefile | 1 +
> drivers/tty/serial/sprd_serial.c | 772 ++++++++++++++++++++++++++++++++++++++
> include/uapi/linux/serial_core.h | 3 +
> 4 files changed, 794 insertions(+)
> create mode 100644 drivers/tty/serial/sprd_serial.c
>
> diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
> index c79b43c..969d3cd 100644
> --- a/drivers/tty/serial/Kconfig
> +++ b/drivers/tty/serial/Kconfig
> @@ -1577,6 +1577,24 @@ config SERIAL_MEN_Z135
> This driver can also be build as a module. If so, the module will be called
> men_z135_uart.ko
>
> +config SERIAL_SPRD
> + tristate "Support for SPRD serial"
> + depends on ARCH_SPRD
> + select SERIAL_CORE
> + help
> + This enables the driver for the Spreadtrum's serial.
> +
> +config SERIAL_SPRD_CONSOLE
> + bool "SPRD UART console support"
> + depends on SERIAL_SPRD=y
> + select SERIAL_CORE_CONSOLE
> + select SERIAL_EARLYCON
> + help
> + Support for early debug console using Spreadtrum's serial. This enables
> + the console before standard serial driver is probed. This is enabled
> + with "earlycon" on the kernel command line. The console is
> + enabled when early_param is processed.
> +
> endmenu
>
> config SERIAL_MCTRL_GPIO
> diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile
> index 9a548ac..4801aca 100644
> --- a/drivers/tty/serial/Makefile
> +++ b/drivers/tty/serial/Makefile
> @@ -93,6 +93,7 @@ obj-$(CONFIG_SERIAL_ARC) += arc_uart.o
> obj-$(CONFIG_SERIAL_RP2) += rp2.o
> obj-$(CONFIG_SERIAL_FSL_LPUART) += fsl_lpuart.o
> obj-$(CONFIG_SERIAL_MEN_Z135) += men_z135_uart.o
> +obj-$(CONFIG_SERIAL_SPRD) += sprd_serial.o
>
> # GPIOLIB helpers for modem control lines
> obj-$(CONFIG_SERIAL_MCTRL_GPIO) += serial_mctrl_gpio.o
> diff --git a/drivers/tty/serial/sprd_serial.c b/drivers/tty/serial/sprd_serial.c
> new file mode 100644
> index 0000000..81839e4
> --- /dev/null
> +++ b/drivers/tty/serial/sprd_serial.c
> @@ -0,0 +1,772 @@
> +/*
> + * Copyright (C) 2012 Spreadtrum Communications Inc.
> + *
> + * This software is licensed under the terms of the GNU General Public
> + * License version 2, as published by the Free Software Foundation, and
> + * may be copied, distributed, and modified under those terms.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/console.h>
> +#include <linux/delay.h>
> +#include <linux/io.h>
> +#include <linux/ioport.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/serial_core.h>
> +#include <linux/serial.h>
> +#include <linux/slab.h>
> +#include <linux/tty.h>
> +#include <linux/tty_flip.h>
> +
> +/* device name */
> +#define UART_NR_MAX 8
> +#define SPRD_TTY_NAME "ttySPX"
> +#define SPRD_FIFO_SIZE 128
> +#define SPRD_DEF_RATE 26000000
> +#define SPRD_TIMEOUT 2048
> +
> +/* the offset of serial registers and BITs for them */
> +/* data registers */
> +#define SPRD_TXD 0x0000
> +#define SPRD_RXD 0x0004
> +
> +/* line status register and its BITs */
> +#define SPRD_LSR 0x0008
> +#define SPRD_LSR_OE BIT(4)
> +#define SPRD_LSR_FE BIT(3)
> +#define SPRD_LSR_PE BIT(2)
> +#define SPRD_LSR_BI BIT(7)
> +#define SPRD_LSR_TX_OVER BIT(15)
> +
> +/* data number in TX and RX fifo */
> +#define SPRD_STS1 0x000C
> +
> +/* interrupt enable register and its BITs */
> +#define SPRD_IEN 0x0010
> +#define SPRD_IEN_RX_FULL BIT(0)
> +#define SPRD_IEN_TX_EMPTY BIT(1)
> +#define SPRD_IEN_BREAK_DETECT BIT(7)
> +#define SPRD_IEN_TIMEOUT BIT(13)
> +
> +/* interrupt clear register */
> +#define SPRD_ICLR 0x0014
> +
> +/* line control register */
> +#define SPRD_LCR 0x0018
> +#define SPRD_LCR_STOP_1BIT 0x10
> +#define SPRD_LCR_STOP_2BIT 0x30
> +#define SPRD_LCR_DATA_LEN (BIT(2) | BIT(3))
> +#define SPRD_LCR_DATA_LEN5 0x0
> +#define SPRD_LCR_DATA_LEN6 0x4
> +#define SPRD_LCR_DATA_LEN7 0x8
> +#define SPRD_LCR_DATA_LEN8 0xc
> +#define SPRD_LCR_PARITY (BIT(0) | BIT(1))
> +#define SPRD_LCR_PARITY_EN 0x2
> +#define SPRD_LCR_EVEN_PAR 0x0
> +#define SPRD_LCR_ODD_PAR 0x1
> +
> +/* control register 1 */
> +#define SPRD_CTL1 0x001C
> +#define RX_HW_FLOW_CTL_THLD BIT(6)
> +#define RX_HW_FLOW_CTL_EN BIT(7)
> +#define TX_HW_FLOW_CTL_EN BIT(8)
> +
> +/* fifo threshold register */
> +#define SPRD_CTL2 0x0020
> +#define THLD_TX_EMPTY 0x40
> +#define THLD_RX_FULL 0x40
> +
> +/* config baud rate register */
> +#define SPRD_CLKD0 0x0024
> +#define SPRD_CLKD1 0x0028
> +
> +/* interrupt mask status register */
> +#define SPRD_IMSR 0x002C
> +#define SPRD_IMSR_RX_FIFO_FULL BIT(0)
> +#define SPRD_IMSR_TX_FIFO_EMPTY BIT(1)
> +#define SPRD_IMSR_BREAK_DETECT BIT(7)
> +#define SPRD_IMSR_TIMEOUT BIT(13)
> +
> +struct reg_backup {
> + uint32_t ien;
> + uint32_t ctrl0;
> + uint32_t ctrl1;
> + uint32_t ctrl2;
> + uint32_t clkd0;
> + uint32_t clkd1;
> + uint32_t dspwait;
> +};
> +
> +struct sprd_uart_port {
> + struct uart_port port;
> + struct reg_backup reg_bak;
> + char name[16];
> +};
> +
> +static struct sprd_uart_port *sprd_port[UART_NR_MAX] = { NULL };
> +
> +static inline unsigned int serial_in(struct uart_port *port, int offset)
> +{
> + return readl_relaxed(port->membase + offset);
> +}
> +
> +static inline void serial_out(struct uart_port *port, int offset, int value)
> +{
> + writel_relaxed(value, port->membase + offset);
> +}
> +
> +static unsigned int sprd_tx_empty(struct uart_port *port)
> +{
> + if (serial_in(port, SPRD_STS1) & 0xff00)
> + return 0;
> + else
> + return TIOCSER_TEMT;
> +}
> +
> +static unsigned int sprd_get_mctrl(struct uart_port *port)
> +{
> + return TIOCM_DSR | TIOCM_CTS;
> +}
> +
> +static void sprd_set_mctrl(struct uart_port *port, unsigned int mctrl)
> +{
> + /* nothing to do */
> +}
> +
> +static void sprd_stop_tx(struct uart_port *port)
> +{
> + unsigned int ien, iclr;
> +
> + iclr = serial_in(port, SPRD_ICLR);
> + ien = serial_in(port, SPRD_IEN);
> +
> + iclr |= SPRD_IEN_TX_EMPTY;
> + ien &= ~SPRD_IEN_TX_EMPTY;
> +
> + serial_out(port, SPRD_ICLR, iclr);
> + serial_out(port, SPRD_IEN, ien);
> +}
> +
> +static void sprd_start_tx(struct uart_port *port)
> +{
> + unsigned int ien;
> +
> + ien = serial_in(port, SPRD_IEN);
> + if (!(ien & SPRD_IEN_TX_EMPTY)) {
> + ien |= SPRD_IEN_TX_EMPTY;
> + serial_out(port, SPRD_IEN, ien);
> + }
> +}
> +
> +static void sprd_stop_rx(struct uart_port *port)
> +{
> + unsigned int ien, iclr;
> +
> + iclr = serial_in(port, SPRD_ICLR);
> + ien = serial_in(port, SPRD_IEN);
> +
> + ien &= ~(SPRD_IEN_RX_FULL | SPRD_IEN_BREAK_DETECT);
> + iclr |= SPRD_IEN_RX_FULL | SPRD_IEN_BREAK_DETECT;
> +
> + serial_out(port, SPRD_IEN, ien);
> + serial_out(port, SPRD_ICLR, iclr);
> +}
> +
> +/* The Sprd serial does not support this function. */
> +static void sprd_break_ctl(struct uart_port *port, int break_state)
> +{
> + /* nothing to do */
> +}
> +
> +static inline int handle_lsr_errors(struct uart_port *port,
> + unsigned int *flag,
> + unsigned int *lsr)
> +{
> + int ret = 0;
> +
> + /* statistics */
> + if (*lsr & SPRD_LSR_BI) {
> + *lsr &= ~(SPRD_LSR_FE | SPRD_LSR_PE);
> + port->icount.brk++;
> + ret = uart_handle_break(port);
> + if (ret)
> + return ret;
> + } else if (*lsr & SPRD_LSR_PE)
> + port->icount.parity++;
> + else if (*lsr & SPRD_LSR_FE)
> + port->icount.frame++;
> + if (*lsr & SPRD_LSR_OE)
> + port->icount.overrun++;
> +
> + /* mask off conditions which should be ignored */
> + *lsr &= port->read_status_mask;
> + if (*lsr & SPRD_LSR_BI)
> + *flag = TTY_BREAK;
> + else if (*lsr & SPRD_LSR_PE)
> + *flag = TTY_PARITY;
> + else if (*lsr & SPRD_LSR_FE)
> + *flag = TTY_FRAME;
> +
> + return ret;
> +}
> +
> +static inline void sprd_rx(int irq, void *dev_id)
> +{
> + struct uart_port *port = dev_id;
> + struct tty_port *tty = &port->state->port;
> + unsigned int ch, flag, lsr, max_count = SPRD_TIMEOUT;
> +
> + while ((serial_in(port, SPRD_STS1) & 0x00ff) && max_count--) {
> + lsr = serial_in(port, SPRD_LSR);
> + ch = serial_in(port, SPRD_RXD);
> + flag = TTY_NORMAL;
> + port->icount.rx++;
> +
> + if (lsr & (SPRD_LSR_BI | SPRD_LSR_PE
> + | SPRD_LSR_FE | SPRD_LSR_OE))
> + if (handle_lsr_errors(port, &lsr, &flag))
> + continue;
> + if (uart_handle_sysrq_char(port, ch))
> + continue;
> +
> + uart_insert_char(port, lsr, SPRD_LSR_OE, ch, flag);
> + }
> +
> + tty_flip_buffer_push(tty);
> +}
> +
> +static inline void sprd_tx(int irq, void *dev_id)
> +{
> + struct uart_port *port = dev_id;
> + struct circ_buf *xmit = &port->state->xmit;
> + int count;
> +
> + if (port->x_char) {
> + serial_out(port, SPRD_TXD, port->x_char);
> + port->icount.tx++;
> + port->x_char = 0;
> + return;
> + }
> +
> + if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
> + sprd_stop_tx(port);
> + return;
> + }
> +
> + count = THLD_TX_EMPTY;
> + do {
> + serial_out(port, SPRD_TXD, xmit->buf[xmit->tail]);
> + xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
> + port->icount.tx++;
> + if (uart_circ_empty(xmit))
> + break;
> + } while (--count > 0);
> +
> + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
> + uart_write_wakeup(port);
> +
> + if (uart_circ_empty(xmit))
> + sprd_stop_tx(port);
> +}
> +
> +/* this handles the interrupt from one port */
> +static irqreturn_t sprd_handle_irq(int irq, void *dev_id)
> +{
> + struct uart_port *port = (struct uart_port *)dev_id;
> + unsigned int ims;
Why does your isr not have to take port->lock ?
> + ims = serial_in(port, SPRD_IMSR);
> +
> + if (!ims)
> + return IRQ_NONE;
> +
> + serial_out(port, SPRD_ICLR, ~0);
> +
> + if (ims & (SPRD_IMSR_RX_FIFO_FULL |
> + SPRD_IMSR_BREAK_DETECT | SPRD_IMSR_TIMEOUT))
> + sprd_rx(irq, port);
> +
> + if (ims & SPRD_IMSR_TX_FIFO_EMPTY)
> + sprd_tx(irq, port);
> +
> + return IRQ_HANDLED;
> +}
> +
> +static int sprd_startup(struct uart_port *port)
> +{
> + int ret = 0;
> + unsigned int ien, ctrl1;
> + unsigned int timeout;
> + struct sprd_uart_port *sp;
> +
> + serial_out(port, SPRD_CTL2, ((THLD_TX_EMPTY << 8) | THLD_RX_FULL));
> +
> + /* clear rx fifo */
> + timeout = SPRD_TIMEOUT;
> + while (timeout-- && serial_in(port, SPRD_STS1) & 0x00ff)
> + serial_in(port, SPRD_RXD);
> +
> + /* clear tx fifo */
> + timeout = SPRD_TIMEOUT;
> + while (timeout-- && serial_in(port, SPRD_STS1) & 0xff00)
> + cpu_relax();
> +
> + /* clear interrupt */
> + serial_out(port, SPRD_IEN, 0x0);
> + serial_out(port, SPRD_ICLR, ~0);
> +
> + /* allocate irq */
> + sp = container_of(port, struct sprd_uart_port, port);
> + snprintf(sp->name, sizeof(sp->name), "sprd_serial%d", port->line);
> + ret = devm_request_irq(port->dev, port->irq, sprd_handle_irq,
> + IRQF_SHARED, sp->name, port);
> + if (ret) {
> + dev_err(port->dev, "fail to request serial irq %d, ret=%d\n",
> + port->irq, ret);
> + return ret;
> + }
> + ctrl1 = serial_in(port, SPRD_CTL1);
> + ctrl1 |= 0x3e00 | THLD_RX_FULL;
> + serial_out(port, SPRD_CTL1, ctrl1);
> +
> + /* enable interrupt */
> + spin_lock(&port->lock);
> + ien = serial_in(port, SPRD_IEN);
> + ien |= SPRD_IEN_RX_FULL | SPRD_IEN_BREAK_DETECT | SPRD_IEN_TIMEOUT;
> + serial_out(port, SPRD_IEN, ien);
> + spin_unlock(&port->lock);
> +
> + return 0;
> +}
> +
> +static void sprd_shutdown(struct uart_port *port)
> +{
> + serial_out(port, SPRD_IEN, 0x0);
> + serial_out(port, SPRD_ICLR, ~0);
> + devm_free_irq(port->dev, port->irq, port);
> +}
> +
> +static void sprd_set_termios(struct uart_port *port,
> + struct ktermios *termios,
> + struct ktermios *old)
> +{
> + unsigned int baud, quot;
> + unsigned int lcr, fc;
> +
> + /* ask the core to calculate the divisor for us */
> + baud = uart_get_baud_rate(port, termios, old, 1200, 3000000);
> +
> + quot = (unsigned int)((port->uartclk + baud / 2) / baud);
> +
> + /* set data length */
> + lcr = serial_in(port, SPRD_LCR);
> + lcr &= ~SPRD_LCR_DATA_LEN;
> + switch (termios->c_cflag & CSIZE) {
> + case CS5:
> + lcr |= SPRD_LCR_DATA_LEN5;
> + break;
> + case CS6:
> + lcr |= SPRD_LCR_DATA_LEN6;
> + break;
> + case CS7:
> + lcr |= SPRD_LCR_DATA_LEN7;
> + break;
> + case CS8:
> + default:
> + lcr |= SPRD_LCR_DATA_LEN8;
> + break;
> + }
> +
> + /* calculate stop bits */
> + lcr &= ~(SPRD_LCR_STOP_1BIT | SPRD_LCR_STOP_2BIT);
> + if (termios->c_cflag & CSTOPB)
> + lcr |= SPRD_LCR_STOP_2BIT;
> + else
> + lcr |= SPRD_LCR_STOP_1BIT;
> +
> + /* calculate parity */
> + lcr &= ~SPRD_LCR_PARITY;
> + termios->c_cflag &= ~CMSPAR; /* no support mark/space */
> + if (termios->c_cflag & PARENB) {
> + lcr |= SPRD_LCR_PARITY_EN;
> + if (termios->c_cflag & PARODD)
> + lcr |= SPRD_LCR_ODD_PAR;
> + else
> + lcr |= SPRD_LCR_EVEN_PAR;
> + }
> +
> + /* change the port state. */
^^^^^^^^^^^^^^^^^^^^^^
This means you should be taking the port->lock here... (and disabling
local interrupts if your isr takes the port->lock)
> + /* update the per-port timeout */
> + uart_update_timeout(port, termios->c_cflag, baud);
> +
> + port->read_status_mask = SPRD_LSR_OE;
> + if (termios->c_iflag & INPCK)
> + port->read_status_mask |= SPRD_LSR_FE | SPRD_LSR_PE;
> + if (termios->c_iflag & (BRKINT | PARMRK))
> + port->read_status_mask |= SPRD_LSR_BI;
> +
> + /* characters to ignore */
> + port->ignore_status_mask = 0;
> + if (termios->c_iflag & IGNPAR)
> + port->ignore_status_mask |= SPRD_LSR_PE | SPRD_LSR_FE;
> + if (termios->c_iflag & IGNBRK) {
> + port->ignore_status_mask |= SPRD_LSR_BI;
> + /*
> + * If we're ignoring parity and break indicators,
> + * ignore overruns too (for real raw support).
> + */
> + if (termios->c_iflag & IGNPAR)
> + port->ignore_status_mask |= SPRD_LSR_OE;
> + }
> +
> + /* flow control */
> + fc = serial_in(port, SPRD_CTL1);
> + fc &= ~(RX_HW_FLOW_CTL_THLD | RX_HW_FLOW_CTL_EN | TX_HW_FLOW_CTL_EN);
> + if (termios->c_cflag & CRTSCTS) {
> + fc |= RX_HW_FLOW_CTL_THLD;
> + fc |= RX_HW_FLOW_CTL_EN;
> + fc |= TX_HW_FLOW_CTL_EN;
> + }
> +
> + /* clock divider bit0~bit15 */
> + serial_out(port, SPRD_CLKD0, quot & 0xffff);
> +
> + /* clock divider bit16~bit20 */
> + serial_out(port, SPRD_CLKD1, (quot & 0x1f0000) >> 16);
> + serial_out(port, SPRD_LCR, lcr);
> + fc |= 0x3e00 | THLD_RX_FULL;
> + serial_out(port, SPRD_CTL1, fc);
and dropping it here.
> + /* Don't rewrite B0 */
> + if (tty_termios_baud_rate(termios))
> + tty_termios_encode_baud_rate(termios, baud, baud);
> +}
> +
> +static const char *sprd_type(struct uart_port *port)
> +{
> + return "SPX";
> +}
> +
> +static void sprd_release_port(struct uart_port *port)
> +{
> + /* nothing to do */
> +}
> +
> +static int sprd_request_port(struct uart_port *port)
> +{
> + return 0;
> +}
> +
> +static void sprd_config_port(struct uart_port *port, int flags)
> +{
> + if (flags & UART_CONFIG_TYPE)
> + port->type = PORT_SPRD;
> +}
> +
> +static int sprd_verify_port(struct uart_port *port,
> + struct serial_struct *ser)
> +{
> + if (ser->type != PORT_SPRD)
> + return -EINVAL;
> + if (port->irq != ser->irq)
> + return -EINVAL;
> + return 0;
> +}
> +
> +static struct uart_ops serial_sprd_ops = {
> + .tx_empty = sprd_tx_empty,
> + .get_mctrl = sprd_get_mctrl,
> + .set_mctrl = sprd_set_mctrl,
> + .stop_tx = sprd_stop_tx,
> + .start_tx = sprd_start_tx,
> + .stop_rx = sprd_stop_rx,
> + .break_ctl = sprd_break_ctl,
> + .startup = sprd_startup,
> + .shutdown = sprd_shutdown,
> + .set_termios = sprd_set_termios,
> + .type = sprd_type,
> + .release_port = sprd_release_port,
> + .request_port = sprd_request_port,
> + .config_port = sprd_config_port,
> + .verify_port = sprd_verify_port,
> +};
> +
> +#ifdef CONFIG_SERIAL_SPRD_CONSOLE
> +static inline void wait_for_xmitr(struct uart_port *port)
> +{
> + unsigned int status, tmout = 10000;
> +
> + /* wait up to 10ms for the character(s) to be sent */
> + do {
> + status = serial_in(port, SPRD_STS1);
> + if (--tmout == 0)
> + break;
> + udelay(1);
> + } while (status & 0xff00);
> +}
> +
> +static void sprd_console_putchar(struct uart_port *port, int ch)
> +{
> + wait_for_xmitr(port);
> + serial_out(port, SPRD_TXD, ch);
> +}
> +
> +static void sprd_console_write(struct console *co, const char *s,
> + unsigned int count)
> +{
> + struct uart_port *port = &sprd_port[co->index]->port;
> + int ien;
> + int locked = 1;
> +
> + if (oops_in_progress)
> + locked = spin_trylock(&port->lock);
> + else
> + spin_lock(&port->lock);
If you do need to take the port->lock in your isr, then you need to
disable local irq here.
> + /* save the IEN then disable the interrupts */
> + ien = serial_in(port, SPRD_IEN);
> + serial_out(port, SPRD_IEN, 0x0);
> +
> + uart_console_write(port, s, count, sprd_console_putchar);
> +
> + /* wait for transmitter to become empty and restore the IEN */
> + wait_for_xmitr(port);
> + serial_out(port, SPRD_IEN, ien);
> + if (locked)
> + spin_unlock(&port->lock);
> +}
> +
> +static int __init sprd_console_setup(struct console *co, char *options)
> +{
> + struct uart_port *port;
> + int baud = 115200;
> + int bits = 8;
> + int parity = 'n';
> + int flow = 'n';
> +
> + if (co->index >= UART_NR_MAX || co->index < 0)
> + co->index = 0;
> +
> + port = &sprd_port[co->index]->port;
> + if (port == NULL) {
> + pr_info("serial port %d not yet initialized\n", co->index);
> + return -ENODEV;
> + }
> + if (options)
> + uart_parse_options(options, &baud, &parity, &bits, &flow);
> +
> + return uart_set_options(port, co, baud, parity, bits, flow);
> +}
> +
> +static struct uart_driver sprd_uart_driver;
> +static struct console sprd_console = {
> + .name = SPRD_TTY_NAME,
> + .write = sprd_console_write,
> + .device = uart_console_device,
> + .setup = sprd_console_setup,
> + .flags = CON_PRINTBUFFER,
> + .index = -1,
> + .data = &sprd_uart_driver,
> +};
> +
> +#define SPRD_CONSOLE (&sprd_console)
> +
> +/* Support for earlycon */
> +static void sprd_putc(struct uart_port *port, int c)
> +{
> + unsigned int timeout = SPRD_TIMEOUT;
> +
> + while (timeout-- &&
> + !(readl(port->membase + SPRD_LSR) & SPRD_LSR_TX_OVER))
> + cpu_relax();
> +
> + writeb(c, port->membase + SPRD_TXD);
> +}
> +
> +static void sprd_early_write(struct console *con, const char *s,
> + unsigned n)
> +{
> + struct earlycon_device *dev = con->data;
> +
> + uart_console_write(&dev->port, s, n, sprd_putc);
> +}
> +
> +static int __init sprd_early_console_setup(
> + struct earlycon_device *device,
> + const char *opt)
> +{
> + if (!device->port.membase)
> + return -ENODEV;
> +
> + device->con->write = sprd_early_write;
> + return 0;
> +}
> +
> +EARLYCON_DECLARE(sprd_serial, sprd_early_console_setup);
> +OF_EARLYCON_DECLARE(sprd_serial, "sprd,sc9836-uart",
> + sprd_early_console_setup);
> +
> +#else /* !CONFIG_SERIAL_SPRD_CONSOLE */
> +#define SPRD_CONSOLE NULL
> +#endif
> +
> +static struct uart_driver sprd_uart_driver = {
> + .owner = THIS_MODULE,
> + .driver_name = "sprd_serial",
> + .dev_name = SPRD_TTY_NAME,
> + .major = 0,
> + .minor = 0,
> + .nr = UART_NR_MAX,
> + .cons = SPRD_CONSOLE,
> +};
> +
> +static int sprd_probe(struct platform_device *pdev)
> +{
> + struct resource *res;
> + struct device_node *np = pdev->dev.of_node;
> + struct uart_port *up;
> + struct clk *clk;
> + int irq;
> +
> + if (np)
> + pdev->id = of_alias_get_id(np, "serial");
> +
> + if (pdev->id < 0 || pdev->id >= UART_NR_MAX) {
> + dev_err(&pdev->dev, "does not support id %d\n", pdev->id);
> + return -ENXIO;
> + }
> +
> + sprd_port[pdev->id] = devm_kzalloc(&pdev->dev,
> + sizeof(*sprd_port[pdev->id]), GFP_KERNEL);
> + if (!sprd_port[pdev->id])
> + return -ENOMEM;
> +
> + up = &sprd_port[pdev->id]->port;
> + up->dev = &pdev->dev;
> + up->line = pdev->id;
> + up->type = PORT_SPRD;
> + up->iotype = SERIAL_IO_PORT;
> + up->uartclk = SPRD_DEF_RATE;
> + up->fifosize = SPRD_FIFO_SIZE;
> + up->ops = &serial_sprd_ops;
> + up->flags = ASYNC_BOOT_AUTOCONF;
> +
> + clk = devm_clk_get(&pdev->dev, NULL);
> + if (!IS_ERR(clk))
> + up->uartclk = clk_get_rate(clk);
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + if (!res) {
> + dev_err(&pdev->dev, "not provide mem resource\n");
> + return -ENODEV;
> + }
> + up->mapbase = res->start;
> + up->membase = devm_ioremap_resource(&pdev->dev, res);
> + if (IS_ERR(up->membase))
> + return PTR_ERR(up->membase);
> +
> + irq = platform_get_irq(pdev, 0);
> + if (irq < 0) {
> + dev_err(&pdev->dev, "not provide irq resource\n");
> + return -ENODEV;
> + }
> + up->irq = irq;
> +
> + platform_set_drvdata(pdev, up);
> +
> + return uart_add_one_port(&sprd_uart_driver, up);
> +}
> +
> +static int sprd_remove(struct platform_device *dev)
> +{
> + struct uart_port *up = platform_get_drvdata(dev);
> +
> + return uart_remove_one_port(&sprd_uart_driver, up);
> +}
> +
> +static int sprd_suspend(struct device *dev)
> +{
> + int id = to_platform_device(dev)->id;
> + struct uart_port *port = &sprd_port[id]->port;
> + struct reg_backup *reg_bak = &sprd_port[id]->reg_bak;
> +
> + reg_bak->ien = serial_in(port, SPRD_IEN);
> + reg_bak->ctrl0 = serial_in(port, SPRD_LCR);
> + reg_bak->ctrl1 = serial_in(port, SPRD_CTL1);
> + reg_bak->ctrl2 = serial_in(port, SPRD_CTL2);
> + reg_bak->clkd0 = serial_in(port, SPRD_CLKD0);
> + reg_bak->clkd1 = serial_in(port, SPRD_CLKD1);
Why are you saving and restoring these register states
across suspend/resume?
The serial core calls your set_termios() handler upon
resume (either for the console or if a tty is open)
so you should be reprogramming the hardware there
based on the termios settings.
Regards,
Peter Hurley
> +
> + uart_suspend_port(&sprd_uart_driver, port);
> +
> + return 0;
> +}
> +
> +static int sprd_resume(struct device *dev)
> +{
> + int id = to_platform_device(dev)->id;
> + struct uart_port *port = &sprd_port[id]->port;
> + struct reg_backup *reg_bak = &sprd_port[id]->reg_bak;
> +
> + serial_out(port, SPRD_LCR, reg_bak->ctrl0);
> + serial_out(port, SPRD_CTL1, reg_bak->ctrl1);
> + serial_out(port, SPRD_CTL2, reg_bak->ctrl2);
> + serial_out(port, SPRD_CLKD0, reg_bak->clkd0);
> + serial_out(port, SPRD_CLKD1, reg_bak->clkd1);
> + serial_out(port, SPRD_IEN, reg_bak->ien);
> +
> + uart_resume_port(&sprd_uart_driver, port);
> +
> + return 0;
> +}
> +
> +static const struct of_device_id serial_ids[] = {
> + {.compatible = "sprd,sc9836-uart",},
> + {}
> +};
> +
> +static SIMPLE_DEV_PM_OPS(sprd_pm_ops, sprd_suspend, sprd_resume);
> +
> +static struct platform_driver sprd_platform_driver = {
> + .probe = sprd_probe,
> + .remove = sprd_remove,
> + .driver = {
> + .name = "sprd_serial",
> + .of_match_table = of_match_ptr(serial_ids),
> + .pm = &sprd_pm_ops,
> + },
> +};
> +
> +static int __init sprd_serial_init(void)
> +{
> + int ret = 0;
> +
> + ret = uart_register_driver(&sprd_uart_driver);
> + if (ret)
> + return ret;
> +
> + ret = platform_driver_register(&sprd_platform_driver);
> + if (ret)
> + uart_unregister_driver(&sprd_uart_driver);
> +
> + return ret;
> +}
> +
> +static void __exit sprd_serial_exit(void)
> +{
> + platform_driver_unregister(&sprd_platform_driver);
> + uart_unregister_driver(&sprd_uart_driver);
> +}
> +
> +module_init(sprd_serial_init);
> +module_exit(sprd_serial_exit);
> +
> +MODULE_LICENSE("GPL v2");
> +MODULE_DESCRIPTION("Spreadtrum SoC serial driver series");
> diff --git a/include/uapi/linux/serial_core.h b/include/uapi/linux/serial_core.h
> index c172180..7e6eb39 100644
> --- a/include/uapi/linux/serial_core.h
> +++ b/include/uapi/linux/serial_core.h
> @@ -248,4 +248,7 @@
> /* MESON */
> #define PORT_MESON 109
>
> +/* SPRD SERIAL */
> +#define PORT_SPRD 110
> +
> #endif /* _UAPILINUX_SERIAL_CORE_H */
>
^ permalink raw reply [flat|nested] 81+ messages in thread* Re: [PATCH v5 5/5] tty/serial: Add Spreadtrum sc9836-uart driver support
@ 2015-01-16 15:20 ` Peter Hurley
0 siblings, 0 replies; 81+ messages in thread
From: Peter Hurley @ 2015-01-16 15:20 UTC (permalink / raw)
To: Chunyan Zhang
Cc: gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r,
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pawel.moll-5wv7dgnIgG8, ijc+devicetree-KcIKpvwj1kUDXYZnReoRVg,
galak-sgV2jX0FEOL9JmXXK+q4OQ, will.deacon-5wv7dgnIgG8,
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florian.vaussard-p8DiymsW2f8, andrew-g2DYL2Zd6BY,
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lanqing.liu-lxIno14LUO0EEoCn2XhGlw,
zhang.lyra-Re5JQEeQqe8AvxtiuMwx3w,
wei.qiao-lxIno14LUO0EEoCn2XhGlw,
devicetree-u79uwXL29TY76Z2rM5mHXA,
linux-api-u79uwXL29TY76Z2rM5mHXA,
linux-kernel-u79uwXL29TY76Z2rM5mHXA,
linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r,
linux-serial-u79uwXL29TY
On 01/16/2015 05:00 AM, Chunyan Zhang wrote:
> Add a full sc9836-uart driver for SC9836 SoC which is based on the
> spreadtrum sharkl64 platform.
> This driver also support earlycon.
> This patch also replaced the spaces between the macros and their
> values with the tabs in serial_core.h
The locking doesn't look correct. Specific notations below.
> Signed-off-by: Chunyan Zhang <chunyan.zhang-lxIno14LUO0EEoCn2XhGlw@public.gmane.org>
> Signed-off-by: Orson Zhai <orson.zhai-lxIno14LUO0EEoCn2XhGlw@public.gmane.org>
> Originally-by: Lanqing Liu <lanqing.liu-lxIno14LUO0EEoCn2XhGlw@public.gmane.org>
> ---
> drivers/tty/serial/Kconfig | 18 +
> drivers/tty/serial/Makefile | 1 +
> drivers/tty/serial/sprd_serial.c | 772 ++++++++++++++++++++++++++++++++++++++
> include/uapi/linux/serial_core.h | 3 +
> 4 files changed, 794 insertions(+)
> create mode 100644 drivers/tty/serial/sprd_serial.c
>
> diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
> index c79b43c..969d3cd 100644
> --- a/drivers/tty/serial/Kconfig
> +++ b/drivers/tty/serial/Kconfig
> @@ -1577,6 +1577,24 @@ config SERIAL_MEN_Z135
> This driver can also be build as a module. If so, the module will be called
> men_z135_uart.ko
>
> +config SERIAL_SPRD
> + tristate "Support for SPRD serial"
> + depends on ARCH_SPRD
> + select SERIAL_CORE
> + help
> + This enables the driver for the Spreadtrum's serial.
> +
> +config SERIAL_SPRD_CONSOLE
> + bool "SPRD UART console support"
> + depends on SERIAL_SPRD=y
> + select SERIAL_CORE_CONSOLE
> + select SERIAL_EARLYCON
> + help
> + Support for early debug console using Spreadtrum's serial. This enables
> + the console before standard serial driver is probed. This is enabled
> + with "earlycon" on the kernel command line. The console is
> + enabled when early_param is processed.
> +
> endmenu
>
> config SERIAL_MCTRL_GPIO
> diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile
> index 9a548ac..4801aca 100644
> --- a/drivers/tty/serial/Makefile
> +++ b/drivers/tty/serial/Makefile
> @@ -93,6 +93,7 @@ obj-$(CONFIG_SERIAL_ARC) += arc_uart.o
> obj-$(CONFIG_SERIAL_RP2) += rp2.o
> obj-$(CONFIG_SERIAL_FSL_LPUART) += fsl_lpuart.o
> obj-$(CONFIG_SERIAL_MEN_Z135) += men_z135_uart.o
> +obj-$(CONFIG_SERIAL_SPRD) += sprd_serial.o
>
> # GPIOLIB helpers for modem control lines
> obj-$(CONFIG_SERIAL_MCTRL_GPIO) += serial_mctrl_gpio.o
> diff --git a/drivers/tty/serial/sprd_serial.c b/drivers/tty/serial/sprd_serial.c
> new file mode 100644
> index 0000000..81839e4
> --- /dev/null
> +++ b/drivers/tty/serial/sprd_serial.c
> @@ -0,0 +1,772 @@
> +/*
> + * Copyright (C) 2012 Spreadtrum Communications Inc.
> + *
> + * This software is licensed under the terms of the GNU General Public
> + * License version 2, as published by the Free Software Foundation, and
> + * may be copied, distributed, and modified under those terms.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/console.h>
> +#include <linux/delay.h>
> +#include <linux/io.h>
> +#include <linux/ioport.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/serial_core.h>
> +#include <linux/serial.h>
> +#include <linux/slab.h>
> +#include <linux/tty.h>
> +#include <linux/tty_flip.h>
> +
> +/* device name */
> +#define UART_NR_MAX 8
> +#define SPRD_TTY_NAME "ttySPX"
> +#define SPRD_FIFO_SIZE 128
> +#define SPRD_DEF_RATE 26000000
> +#define SPRD_TIMEOUT 2048
> +
> +/* the offset of serial registers and BITs for them */
> +/* data registers */
> +#define SPRD_TXD 0x0000
> +#define SPRD_RXD 0x0004
> +
> +/* line status register and its BITs */
> +#define SPRD_LSR 0x0008
> +#define SPRD_LSR_OE BIT(4)
> +#define SPRD_LSR_FE BIT(3)
> +#define SPRD_LSR_PE BIT(2)
> +#define SPRD_LSR_BI BIT(7)
> +#define SPRD_LSR_TX_OVER BIT(15)
> +
> +/* data number in TX and RX fifo */
> +#define SPRD_STS1 0x000C
> +
> +/* interrupt enable register and its BITs */
> +#define SPRD_IEN 0x0010
> +#define SPRD_IEN_RX_FULL BIT(0)
> +#define SPRD_IEN_TX_EMPTY BIT(1)
> +#define SPRD_IEN_BREAK_DETECT BIT(7)
> +#define SPRD_IEN_TIMEOUT BIT(13)
> +
> +/* interrupt clear register */
> +#define SPRD_ICLR 0x0014
> +
> +/* line control register */
> +#define SPRD_LCR 0x0018
> +#define SPRD_LCR_STOP_1BIT 0x10
> +#define SPRD_LCR_STOP_2BIT 0x30
> +#define SPRD_LCR_DATA_LEN (BIT(2) | BIT(3))
> +#define SPRD_LCR_DATA_LEN5 0x0
> +#define SPRD_LCR_DATA_LEN6 0x4
> +#define SPRD_LCR_DATA_LEN7 0x8
> +#define SPRD_LCR_DATA_LEN8 0xc
> +#define SPRD_LCR_PARITY (BIT(0) | BIT(1))
> +#define SPRD_LCR_PARITY_EN 0x2
> +#define SPRD_LCR_EVEN_PAR 0x0
> +#define SPRD_LCR_ODD_PAR 0x1
> +
> +/* control register 1 */
> +#define SPRD_CTL1 0x001C
> +#define RX_HW_FLOW_CTL_THLD BIT(6)
> +#define RX_HW_FLOW_CTL_EN BIT(7)
> +#define TX_HW_FLOW_CTL_EN BIT(8)
> +
> +/* fifo threshold register */
> +#define SPRD_CTL2 0x0020
> +#define THLD_TX_EMPTY 0x40
> +#define THLD_RX_FULL 0x40
> +
> +/* config baud rate register */
> +#define SPRD_CLKD0 0x0024
> +#define SPRD_CLKD1 0x0028
> +
> +/* interrupt mask status register */
> +#define SPRD_IMSR 0x002C
> +#define SPRD_IMSR_RX_FIFO_FULL BIT(0)
> +#define SPRD_IMSR_TX_FIFO_EMPTY BIT(1)
> +#define SPRD_IMSR_BREAK_DETECT BIT(7)
> +#define SPRD_IMSR_TIMEOUT BIT(13)
> +
> +struct reg_backup {
> + uint32_t ien;
> + uint32_t ctrl0;
> + uint32_t ctrl1;
> + uint32_t ctrl2;
> + uint32_t clkd0;
> + uint32_t clkd1;
> + uint32_t dspwait;
> +};
> +
> +struct sprd_uart_port {
> + struct uart_port port;
> + struct reg_backup reg_bak;
> + char name[16];
> +};
> +
> +static struct sprd_uart_port *sprd_port[UART_NR_MAX] = { NULL };
> +
> +static inline unsigned int serial_in(struct uart_port *port, int offset)
> +{
> + return readl_relaxed(port->membase + offset);
> +}
> +
> +static inline void serial_out(struct uart_port *port, int offset, int value)
> +{
> + writel_relaxed(value, port->membase + offset);
> +}
> +
> +static unsigned int sprd_tx_empty(struct uart_port *port)
> +{
> + if (serial_in(port, SPRD_STS1) & 0xff00)
> + return 0;
> + else
> + return TIOCSER_TEMT;
> +}
> +
> +static unsigned int sprd_get_mctrl(struct uart_port *port)
> +{
> + return TIOCM_DSR | TIOCM_CTS;
> +}
> +
> +static void sprd_set_mctrl(struct uart_port *port, unsigned int mctrl)
> +{
> + /* nothing to do */
> +}
> +
> +static void sprd_stop_tx(struct uart_port *port)
> +{
> + unsigned int ien, iclr;
> +
> + iclr = serial_in(port, SPRD_ICLR);
> + ien = serial_in(port, SPRD_IEN);
> +
> + iclr |= SPRD_IEN_TX_EMPTY;
> + ien &= ~SPRD_IEN_TX_EMPTY;
> +
> + serial_out(port, SPRD_ICLR, iclr);
> + serial_out(port, SPRD_IEN, ien);
> +}
> +
> +static void sprd_start_tx(struct uart_port *port)
> +{
> + unsigned int ien;
> +
> + ien = serial_in(port, SPRD_IEN);
> + if (!(ien & SPRD_IEN_TX_EMPTY)) {
> + ien |= SPRD_IEN_TX_EMPTY;
> + serial_out(port, SPRD_IEN, ien);
> + }
> +}
> +
> +static void sprd_stop_rx(struct uart_port *port)
> +{
> + unsigned int ien, iclr;
> +
> + iclr = serial_in(port, SPRD_ICLR);
> + ien = serial_in(port, SPRD_IEN);
> +
> + ien &= ~(SPRD_IEN_RX_FULL | SPRD_IEN_BREAK_DETECT);
> + iclr |= SPRD_IEN_RX_FULL | SPRD_IEN_BREAK_DETECT;
> +
> + serial_out(port, SPRD_IEN, ien);
> + serial_out(port, SPRD_ICLR, iclr);
> +}
> +
> +/* The Sprd serial does not support this function. */
> +static void sprd_break_ctl(struct uart_port *port, int break_state)
> +{
> + /* nothing to do */
> +}
> +
> +static inline int handle_lsr_errors(struct uart_port *port,
> + unsigned int *flag,
> + unsigned int *lsr)
> +{
> + int ret = 0;
> +
> + /* statistics */
> + if (*lsr & SPRD_LSR_BI) {
> + *lsr &= ~(SPRD_LSR_FE | SPRD_LSR_PE);
> + port->icount.brk++;
> + ret = uart_handle_break(port);
> + if (ret)
> + return ret;
> + } else if (*lsr & SPRD_LSR_PE)
> + port->icount.parity++;
> + else if (*lsr & SPRD_LSR_FE)
> + port->icount.frame++;
> + if (*lsr & SPRD_LSR_OE)
> + port->icount.overrun++;
> +
> + /* mask off conditions which should be ignored */
> + *lsr &= port->read_status_mask;
> + if (*lsr & SPRD_LSR_BI)
> + *flag = TTY_BREAK;
> + else if (*lsr & SPRD_LSR_PE)
> + *flag = TTY_PARITY;
> + else if (*lsr & SPRD_LSR_FE)
> + *flag = TTY_FRAME;
> +
> + return ret;
> +}
> +
> +static inline void sprd_rx(int irq, void *dev_id)
> +{
> + struct uart_port *port = dev_id;
> + struct tty_port *tty = &port->state->port;
> + unsigned int ch, flag, lsr, max_count = SPRD_TIMEOUT;
> +
> + while ((serial_in(port, SPRD_STS1) & 0x00ff) && max_count--) {
> + lsr = serial_in(port, SPRD_LSR);
> + ch = serial_in(port, SPRD_RXD);
> + flag = TTY_NORMAL;
> + port->icount.rx++;
> +
> + if (lsr & (SPRD_LSR_BI | SPRD_LSR_PE
> + | SPRD_LSR_FE | SPRD_LSR_OE))
> + if (handle_lsr_errors(port, &lsr, &flag))
> + continue;
> + if (uart_handle_sysrq_char(port, ch))
> + continue;
> +
> + uart_insert_char(port, lsr, SPRD_LSR_OE, ch, flag);
> + }
> +
> + tty_flip_buffer_push(tty);
> +}
> +
> +static inline void sprd_tx(int irq, void *dev_id)
> +{
> + struct uart_port *port = dev_id;
> + struct circ_buf *xmit = &port->state->xmit;
> + int count;
> +
> + if (port->x_char) {
> + serial_out(port, SPRD_TXD, port->x_char);
> + port->icount.tx++;
> + port->x_char = 0;
> + return;
> + }
> +
> + if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
> + sprd_stop_tx(port);
> + return;
> + }
> +
> + count = THLD_TX_EMPTY;
> + do {
> + serial_out(port, SPRD_TXD, xmit->buf[xmit->tail]);
> + xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
> + port->icount.tx++;
> + if (uart_circ_empty(xmit))
> + break;
> + } while (--count > 0);
> +
> + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
> + uart_write_wakeup(port);
> +
> + if (uart_circ_empty(xmit))
> + sprd_stop_tx(port);
> +}
> +
> +/* this handles the interrupt from one port */
> +static irqreturn_t sprd_handle_irq(int irq, void *dev_id)
> +{
> + struct uart_port *port = (struct uart_port *)dev_id;
> + unsigned int ims;
Why does your isr not have to take port->lock ?
> + ims = serial_in(port, SPRD_IMSR);
> +
> + if (!ims)
> + return IRQ_NONE;
> +
> + serial_out(port, SPRD_ICLR, ~0);
> +
> + if (ims & (SPRD_IMSR_RX_FIFO_FULL |
> + SPRD_IMSR_BREAK_DETECT | SPRD_IMSR_TIMEOUT))
> + sprd_rx(irq, port);
> +
> + if (ims & SPRD_IMSR_TX_FIFO_EMPTY)
> + sprd_tx(irq, port);
> +
> + return IRQ_HANDLED;
> +}
> +
> +static int sprd_startup(struct uart_port *port)
> +{
> + int ret = 0;
> + unsigned int ien, ctrl1;
> + unsigned int timeout;
> + struct sprd_uart_port *sp;
> +
> + serial_out(port, SPRD_CTL2, ((THLD_TX_EMPTY << 8) | THLD_RX_FULL));
> +
> + /* clear rx fifo */
> + timeout = SPRD_TIMEOUT;
> + while (timeout-- && serial_in(port, SPRD_STS1) & 0x00ff)
> + serial_in(port, SPRD_RXD);
> +
> + /* clear tx fifo */
> + timeout = SPRD_TIMEOUT;
> + while (timeout-- && serial_in(port, SPRD_STS1) & 0xff00)
> + cpu_relax();
> +
> + /* clear interrupt */
> + serial_out(port, SPRD_IEN, 0x0);
> + serial_out(port, SPRD_ICLR, ~0);
> +
> + /* allocate irq */
> + sp = container_of(port, struct sprd_uart_port, port);
> + snprintf(sp->name, sizeof(sp->name), "sprd_serial%d", port->line);
> + ret = devm_request_irq(port->dev, port->irq, sprd_handle_irq,
> + IRQF_SHARED, sp->name, port);
> + if (ret) {
> + dev_err(port->dev, "fail to request serial irq %d, ret=%d\n",
> + port->irq, ret);
> + return ret;
> + }
> + ctrl1 = serial_in(port, SPRD_CTL1);
> + ctrl1 |= 0x3e00 | THLD_RX_FULL;
> + serial_out(port, SPRD_CTL1, ctrl1);
> +
> + /* enable interrupt */
> + spin_lock(&port->lock);
> + ien = serial_in(port, SPRD_IEN);
> + ien |= SPRD_IEN_RX_FULL | SPRD_IEN_BREAK_DETECT | SPRD_IEN_TIMEOUT;
> + serial_out(port, SPRD_IEN, ien);
> + spin_unlock(&port->lock);
> +
> + return 0;
> +}
> +
> +static void sprd_shutdown(struct uart_port *port)
> +{
> + serial_out(port, SPRD_IEN, 0x0);
> + serial_out(port, SPRD_ICLR, ~0);
> + devm_free_irq(port->dev, port->irq, port);
> +}
> +
> +static void sprd_set_termios(struct uart_port *port,
> + struct ktermios *termios,
> + struct ktermios *old)
> +{
> + unsigned int baud, quot;
> + unsigned int lcr, fc;
> +
> + /* ask the core to calculate the divisor for us */
> + baud = uart_get_baud_rate(port, termios, old, 1200, 3000000);
> +
> + quot = (unsigned int)((port->uartclk + baud / 2) / baud);
> +
> + /* set data length */
> + lcr = serial_in(port, SPRD_LCR);
> + lcr &= ~SPRD_LCR_DATA_LEN;
> + switch (termios->c_cflag & CSIZE) {
> + case CS5:
> + lcr |= SPRD_LCR_DATA_LEN5;
> + break;
> + case CS6:
> + lcr |= SPRD_LCR_DATA_LEN6;
> + break;
> + case CS7:
> + lcr |= SPRD_LCR_DATA_LEN7;
> + break;
> + case CS8:
> + default:
> + lcr |= SPRD_LCR_DATA_LEN8;
> + break;
> + }
> +
> + /* calculate stop bits */
> + lcr &= ~(SPRD_LCR_STOP_1BIT | SPRD_LCR_STOP_2BIT);
> + if (termios->c_cflag & CSTOPB)
> + lcr |= SPRD_LCR_STOP_2BIT;
> + else
> + lcr |= SPRD_LCR_STOP_1BIT;
> +
> + /* calculate parity */
> + lcr &= ~SPRD_LCR_PARITY;
> + termios->c_cflag &= ~CMSPAR; /* no support mark/space */
> + if (termios->c_cflag & PARENB) {
> + lcr |= SPRD_LCR_PARITY_EN;
> + if (termios->c_cflag & PARODD)
> + lcr |= SPRD_LCR_ODD_PAR;
> + else
> + lcr |= SPRD_LCR_EVEN_PAR;
> + }
> +
> + /* change the port state. */
^^^^^^^^^^^^^^^^^^^^^^
This means you should be taking the port->lock here... (and disabling
local interrupts if your isr takes the port->lock)
> + /* update the per-port timeout */
> + uart_update_timeout(port, termios->c_cflag, baud);
> +
> + port->read_status_mask = SPRD_LSR_OE;
> + if (termios->c_iflag & INPCK)
> + port->read_status_mask |= SPRD_LSR_FE | SPRD_LSR_PE;
> + if (termios->c_iflag & (BRKINT | PARMRK))
> + port->read_status_mask |= SPRD_LSR_BI;
> +
> + /* characters to ignore */
> + port->ignore_status_mask = 0;
> + if (termios->c_iflag & IGNPAR)
> + port->ignore_status_mask |= SPRD_LSR_PE | SPRD_LSR_FE;
> + if (termios->c_iflag & IGNBRK) {
> + port->ignore_status_mask |= SPRD_LSR_BI;
> + /*
> + * If we're ignoring parity and break indicators,
> + * ignore overruns too (for real raw support).
> + */
> + if (termios->c_iflag & IGNPAR)
> + port->ignore_status_mask |= SPRD_LSR_OE;
> + }
> +
> + /* flow control */
> + fc = serial_in(port, SPRD_CTL1);
> + fc &= ~(RX_HW_FLOW_CTL_THLD | RX_HW_FLOW_CTL_EN | TX_HW_FLOW_CTL_EN);
> + if (termios->c_cflag & CRTSCTS) {
> + fc |= RX_HW_FLOW_CTL_THLD;
> + fc |= RX_HW_FLOW_CTL_EN;
> + fc |= TX_HW_FLOW_CTL_EN;
> + }
> +
> + /* clock divider bit0~bit15 */
> + serial_out(port, SPRD_CLKD0, quot & 0xffff);
> +
> + /* clock divider bit16~bit20 */
> + serial_out(port, SPRD_CLKD1, (quot & 0x1f0000) >> 16);
> + serial_out(port, SPRD_LCR, lcr);
> + fc |= 0x3e00 | THLD_RX_FULL;
> + serial_out(port, SPRD_CTL1, fc);
and dropping it here.
> + /* Don't rewrite B0 */
> + if (tty_termios_baud_rate(termios))
> + tty_termios_encode_baud_rate(termios, baud, baud);
> +}
> +
> +static const char *sprd_type(struct uart_port *port)
> +{
> + return "SPX";
> +}
> +
> +static void sprd_release_port(struct uart_port *port)
> +{
> + /* nothing to do */
> +}
> +
> +static int sprd_request_port(struct uart_port *port)
> +{
> + return 0;
> +}
> +
> +static void sprd_config_port(struct uart_port *port, int flags)
> +{
> + if (flags & UART_CONFIG_TYPE)
> + port->type = PORT_SPRD;
> +}
> +
> +static int sprd_verify_port(struct uart_port *port,
> + struct serial_struct *ser)
> +{
> + if (ser->type != PORT_SPRD)
> + return -EINVAL;
> + if (port->irq != ser->irq)
> + return -EINVAL;
> + return 0;
> +}
> +
> +static struct uart_ops serial_sprd_ops = {
> + .tx_empty = sprd_tx_empty,
> + .get_mctrl = sprd_get_mctrl,
> + .set_mctrl = sprd_set_mctrl,
> + .stop_tx = sprd_stop_tx,
> + .start_tx = sprd_start_tx,
> + .stop_rx = sprd_stop_rx,
> + .break_ctl = sprd_break_ctl,
> + .startup = sprd_startup,
> + .shutdown = sprd_shutdown,
> + .set_termios = sprd_set_termios,
> + .type = sprd_type,
> + .release_port = sprd_release_port,
> + .request_port = sprd_request_port,
> + .config_port = sprd_config_port,
> + .verify_port = sprd_verify_port,
> +};
> +
> +#ifdef CONFIG_SERIAL_SPRD_CONSOLE
> +static inline void wait_for_xmitr(struct uart_port *port)
> +{
> + unsigned int status, tmout = 10000;
> +
> + /* wait up to 10ms for the character(s) to be sent */
> + do {
> + status = serial_in(port, SPRD_STS1);
> + if (--tmout == 0)
> + break;
> + udelay(1);
> + } while (status & 0xff00);
> +}
> +
> +static void sprd_console_putchar(struct uart_port *port, int ch)
> +{
> + wait_for_xmitr(port);
> + serial_out(port, SPRD_TXD, ch);
> +}
> +
> +static void sprd_console_write(struct console *co, const char *s,
> + unsigned int count)
> +{
> + struct uart_port *port = &sprd_port[co->index]->port;
> + int ien;
> + int locked = 1;
> +
> + if (oops_in_progress)
> + locked = spin_trylock(&port->lock);
> + else
> + spin_lock(&port->lock);
If you do need to take the port->lock in your isr, then you need to
disable local irq here.
> + /* save the IEN then disable the interrupts */
> + ien = serial_in(port, SPRD_IEN);
> + serial_out(port, SPRD_IEN, 0x0);
> +
> + uart_console_write(port, s, count, sprd_console_putchar);
> +
> + /* wait for transmitter to become empty and restore the IEN */
> + wait_for_xmitr(port);
> + serial_out(port, SPRD_IEN, ien);
> + if (locked)
> + spin_unlock(&port->lock);
> +}
> +
> +static int __init sprd_console_setup(struct console *co, char *options)
> +{
> + struct uart_port *port;
> + int baud = 115200;
> + int bits = 8;
> + int parity = 'n';
> + int flow = 'n';
> +
> + if (co->index >= UART_NR_MAX || co->index < 0)
> + co->index = 0;
> +
> + port = &sprd_port[co->index]->port;
> + if (port == NULL) {
> + pr_info("serial port %d not yet initialized\n", co->index);
> + return -ENODEV;
> + }
> + if (options)
> + uart_parse_options(options, &baud, &parity, &bits, &flow);
> +
> + return uart_set_options(port, co, baud, parity, bits, flow);
> +}
> +
> +static struct uart_driver sprd_uart_driver;
> +static struct console sprd_console = {
> + .name = SPRD_TTY_NAME,
> + .write = sprd_console_write,
> + .device = uart_console_device,
> + .setup = sprd_console_setup,
> + .flags = CON_PRINTBUFFER,
> + .index = -1,
> + .data = &sprd_uart_driver,
> +};
> +
> +#define SPRD_CONSOLE (&sprd_console)
> +
> +/* Support for earlycon */
> +static void sprd_putc(struct uart_port *port, int c)
> +{
> + unsigned int timeout = SPRD_TIMEOUT;
> +
> + while (timeout-- &&
> + !(readl(port->membase + SPRD_LSR) & SPRD_LSR_TX_OVER))
> + cpu_relax();
> +
> + writeb(c, port->membase + SPRD_TXD);
> +}
> +
> +static void sprd_early_write(struct console *con, const char *s,
> + unsigned n)
> +{
> + struct earlycon_device *dev = con->data;
> +
> + uart_console_write(&dev->port, s, n, sprd_putc);
> +}
> +
> +static int __init sprd_early_console_setup(
> + struct earlycon_device *device,
> + const char *opt)
> +{
> + if (!device->port.membase)
> + return -ENODEV;
> +
> + device->con->write = sprd_early_write;
> + return 0;
> +}
> +
> +EARLYCON_DECLARE(sprd_serial, sprd_early_console_setup);
> +OF_EARLYCON_DECLARE(sprd_serial, "sprd,sc9836-uart",
> + sprd_early_console_setup);
> +
> +#else /* !CONFIG_SERIAL_SPRD_CONSOLE */
> +#define SPRD_CONSOLE NULL
> +#endif
> +
> +static struct uart_driver sprd_uart_driver = {
> + .owner = THIS_MODULE,
> + .driver_name = "sprd_serial",
> + .dev_name = SPRD_TTY_NAME,
> + .major = 0,
> + .minor = 0,
> + .nr = UART_NR_MAX,
> + .cons = SPRD_CONSOLE,
> +};
> +
> +static int sprd_probe(struct platform_device *pdev)
> +{
> + struct resource *res;
> + struct device_node *np = pdev->dev.of_node;
> + struct uart_port *up;
> + struct clk *clk;
> + int irq;
> +
> + if (np)
> + pdev->id = of_alias_get_id(np, "serial");
> +
> + if (pdev->id < 0 || pdev->id >= UART_NR_MAX) {
> + dev_err(&pdev->dev, "does not support id %d\n", pdev->id);
> + return -ENXIO;
> + }
> +
> + sprd_port[pdev->id] = devm_kzalloc(&pdev->dev,
> + sizeof(*sprd_port[pdev->id]), GFP_KERNEL);
> + if (!sprd_port[pdev->id])
> + return -ENOMEM;
> +
> + up = &sprd_port[pdev->id]->port;
> + up->dev = &pdev->dev;
> + up->line = pdev->id;
> + up->type = PORT_SPRD;
> + up->iotype = SERIAL_IO_PORT;
> + up->uartclk = SPRD_DEF_RATE;
> + up->fifosize = SPRD_FIFO_SIZE;
> + up->ops = &serial_sprd_ops;
> + up->flags = ASYNC_BOOT_AUTOCONF;
> +
> + clk = devm_clk_get(&pdev->dev, NULL);
> + if (!IS_ERR(clk))
> + up->uartclk = clk_get_rate(clk);
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + if (!res) {
> + dev_err(&pdev->dev, "not provide mem resource\n");
> + return -ENODEV;
> + }
> + up->mapbase = res->start;
> + up->membase = devm_ioremap_resource(&pdev->dev, res);
> + if (IS_ERR(up->membase))
> + return PTR_ERR(up->membase);
> +
> + irq = platform_get_irq(pdev, 0);
> + if (irq < 0) {
> + dev_err(&pdev->dev, "not provide irq resource\n");
> + return -ENODEV;
> + }
> + up->irq = irq;
> +
> + platform_set_drvdata(pdev, up);
> +
> + return uart_add_one_port(&sprd_uart_driver, up);
> +}
> +
> +static int sprd_remove(struct platform_device *dev)
> +{
> + struct uart_port *up = platform_get_drvdata(dev);
> +
> + return uart_remove_one_port(&sprd_uart_driver, up);
> +}
> +
> +static int sprd_suspend(struct device *dev)
> +{
> + int id = to_platform_device(dev)->id;
> + struct uart_port *port = &sprd_port[id]->port;
> + struct reg_backup *reg_bak = &sprd_port[id]->reg_bak;
> +
> + reg_bak->ien = serial_in(port, SPRD_IEN);
> + reg_bak->ctrl0 = serial_in(port, SPRD_LCR);
> + reg_bak->ctrl1 = serial_in(port, SPRD_CTL1);
> + reg_bak->ctrl2 = serial_in(port, SPRD_CTL2);
> + reg_bak->clkd0 = serial_in(port, SPRD_CLKD0);
> + reg_bak->clkd1 = serial_in(port, SPRD_CLKD1);
Why are you saving and restoring these register states
across suspend/resume?
The serial core calls your set_termios() handler upon
resume (either for the console or if a tty is open)
so you should be reprogramming the hardware there
based on the termios settings.
Regards,
Peter Hurley
> +
> + uart_suspend_port(&sprd_uart_driver, port);
> +
> + return 0;
> +}
> +
> +static int sprd_resume(struct device *dev)
> +{
> + int id = to_platform_device(dev)->id;
> + struct uart_port *port = &sprd_port[id]->port;
> + struct reg_backup *reg_bak = &sprd_port[id]->reg_bak;
> +
> + serial_out(port, SPRD_LCR, reg_bak->ctrl0);
> + serial_out(port, SPRD_CTL1, reg_bak->ctrl1);
> + serial_out(port, SPRD_CTL2, reg_bak->ctrl2);
> + serial_out(port, SPRD_CLKD0, reg_bak->clkd0);
> + serial_out(port, SPRD_CLKD1, reg_bak->clkd1);
> + serial_out(port, SPRD_IEN, reg_bak->ien);
> +
> + uart_resume_port(&sprd_uart_driver, port);
> +
> + return 0;
> +}
> +
> +static const struct of_device_id serial_ids[] = {
> + {.compatible = "sprd,sc9836-uart",},
> + {}
> +};
> +
> +static SIMPLE_DEV_PM_OPS(sprd_pm_ops, sprd_suspend, sprd_resume);
> +
> +static struct platform_driver sprd_platform_driver = {
> + .probe = sprd_probe,
> + .remove = sprd_remove,
> + .driver = {
> + .name = "sprd_serial",
> + .of_match_table = of_match_ptr(serial_ids),
> + .pm = &sprd_pm_ops,
> + },
> +};
> +
> +static int __init sprd_serial_init(void)
> +{
> + int ret = 0;
> +
> + ret = uart_register_driver(&sprd_uart_driver);
> + if (ret)
> + return ret;
> +
> + ret = platform_driver_register(&sprd_platform_driver);
> + if (ret)
> + uart_unregister_driver(&sprd_uart_driver);
> +
> + return ret;
> +}
> +
> +static void __exit sprd_serial_exit(void)
> +{
> + platform_driver_unregister(&sprd_platform_driver);
> + uart_unregister_driver(&sprd_uart_driver);
> +}
> +
> +module_init(sprd_serial_init);
> +module_exit(sprd_serial_exit);
> +
> +MODULE_LICENSE("GPL v2");
> +MODULE_DESCRIPTION("Spreadtrum SoC serial driver series");
> diff --git a/include/uapi/linux/serial_core.h b/include/uapi/linux/serial_core.h
> index c172180..7e6eb39 100644
> --- a/include/uapi/linux/serial_core.h
> +++ b/include/uapi/linux/serial_core.h
> @@ -248,4 +248,7 @@
> /* MESON */
> #define PORT_MESON 109
>
> +/* SPRD SERIAL */
> +#define PORT_SPRD 110
> +
> #endif /* _UAPILINUX_SERIAL_CORE_H */
>
^ permalink raw reply [flat|nested] 81+ messages in thread* Re: [PATCH v5 5/5] tty/serial: Add Spreadtrum sc9836-uart driver support
2015-01-16 15:20 ` Peter Hurley
@ 2015-01-20 12:11 ` Orson Zhai
-1 siblings, 0 replies; 81+ messages in thread
From: Orson Zhai @ 2015-01-20 12:11 UTC (permalink / raw)
To: Peter Hurley, Chunyan Zhang
Cc: gregkh, mark.rutland, arnd, gnomes, broonie, robh+dt, pawel.moll,
ijc+devicetree, galak, will.deacon, catalin.marinas, jslaby,
jason, heiko, florian.vaussard, andrew, rrichter, hytszk,
grant.likely, antonynpavlov, Joel.Schopp, Suravee.Suthikulpanit,
shawn.guo, lea.yan, jorge.ramirez-ortiz, lee.jones, geng.ren,
zhizhou.zhang, lanqing.liu, zhang.lyra, wei.qiao, linux-kernel,
linux-arm-kernel, linux-serial
Hi, Peter,
Thank you for reviewing our code!
Some discussion below.
On 2015年01月16日 23:20, Peter Hurley wrote:
> On 01/16/2015 05:00 AM, Chunyan Zhang wrote:
>> Add a full sc9836-uart driver for SC9836 SoC which is based on the
>> spreadtrum sharkl64 platform.
>> This driver also support earlycon.
>> This patch also replaced the spaces between the macros and their
>> values with the tabs in serial_core.h
> The locking doesn't look correct. Specific notations below.
>
>> Signed-off-by: Chunyan Zhang <chunyan.zhang@spreadtrum.com>
>> Signed-off-by: Orson Zhai <orson.zhai@spreadtrum.com>
>> Originally-by: Lanqing Liu <lanqing.liu@spreadtrum.com>
>> ---
>> drivers/tty/serial/Kconfig | 18 +
>> drivers/tty/serial/Makefile | 1 +
>> drivers/tty/serial/sprd_serial.c | 772 ++++++++++++++++++++++++++++++++++++++
>> include/uapi/linux/serial_core.h | 3 +
>> 4 files changed, 794 insertions(+)
>> create mode 100644 drivers/tty/serial/sprd_serial.c
>>
>> diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
>> index c79b43c..969d3cd 100644
>> --- a/drivers/tty/serial/Kconfig
>> +++ b/drivers/tty/serial/Kconfig
>> @@ -1577,6 +1577,24 @@ config SERIAL_MEN_Z135
>> This driver can also be build as a module. If so, the module will be called
>> men_z135_uart.ko
>>
>> +config SERIAL_SPRD
>> + tristate "Support for SPRD serial"
>> + depends on ARCH_SPRD
>> + select SERIAL_CORE
>> + help
>> + This enables the driver for the Spreadtrum's serial.
>> +
>> +config SERIAL_SPRD_CONSOLE
>> + bool "SPRD UART console support"
>> + depends on SERIAL_SPRD=y
>> + select SERIAL_CORE_CONSOLE
>> + select SERIAL_EARLYCON
>> + help
>> + Support for early debug console using Spreadtrum's serial. This enables
>> + the console before standard serial driver is probed. This is enabled
>> + with "earlycon" on the kernel command line. The console is
>> + enabled when early_param is processed.
>> +
>> endmenu
>>
>> config SERIAL_MCTRL_GPIO
>> diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile
>> index 9a548ac..4801aca 100644
>> --- a/drivers/tty/serial/Makefile
>> +++ b/drivers/tty/serial/Makefile
>> @@ -93,6 +93,7 @@ obj-$(CONFIG_SERIAL_ARC) += arc_uart.o
>> obj-$(CONFIG_SERIAL_RP2) += rp2.o
>> obj-$(CONFIG_SERIAL_FSL_LPUART) += fsl_lpuart.o
>> obj-$(CONFIG_SERIAL_MEN_Z135) += men_z135_uart.o
>> +obj-$(CONFIG_SERIAL_SPRD) += sprd_serial.o
>>
>> # GPIOLIB helpers for modem control lines
>> obj-$(CONFIG_SERIAL_MCTRL_GPIO) += serial_mctrl_gpio.o
>> diff --git a/drivers/tty/serial/sprd_serial.c b/drivers/tty/serial/sprd_serial.c
>> new file mode 100644
>> index 0000000..81839e4
>> --- /dev/null
>> +++ b/drivers/tty/serial/sprd_serial.c
>> @@ -0,0 +1,772 @@
>> +/*
>> + * Copyright (C) 2012 Spreadtrum Communications Inc.
>> + *
>> + * This software is licensed under the terms of the GNU General Public
>> + * License version 2, as published by the Free Software Foundation, and
>> + * may be copied, distributed, and modified under those terms.
>> + *
>> + * This program is distributed in the hope that it will be useful,
>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
>> + * GNU General Public License for more details.
>> + */
>> +
>> +#include <linux/clk.h>
>> +#include <linux/console.h>
>> +#include <linux/delay.h>
>> +#include <linux/io.h>
>> +#include <linux/ioport.h>
>> +#include <linux/kernel.h>
>> +#include <linux/module.h>
>> +#include <linux/of.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/serial_core.h>
>> +#include <linux/serial.h>
>> +#include <linux/slab.h>
>> +#include <linux/tty.h>
>> +#include <linux/tty_flip.h>
>> +
>> +/* device name */
>> +#define UART_NR_MAX 8
>> +#define SPRD_TTY_NAME "ttySPX"
>> +#define SPRD_FIFO_SIZE 128
>> +#define SPRD_DEF_RATE 26000000
>> +#define SPRD_TIMEOUT 2048
>> +
>> +/* the offset of serial registers and BITs for them */
>> +/* data registers */
>> +#define SPRD_TXD 0x0000
>> +#define SPRD_RXD 0x0004
>> +
>> +/* line status register and its BITs */
>> +#define SPRD_LSR 0x0008
>> +#define SPRD_LSR_OE BIT(4)
>> +#define SPRD_LSR_FE BIT(3)
>> +#define SPRD_LSR_PE BIT(2)
>> +#define SPRD_LSR_BI BIT(7)
>> +#define SPRD_LSR_TX_OVER BIT(15)
>> +
>> +/* data number in TX and RX fifo */
>> +#define SPRD_STS1 0x000C
>> +
>> +/* interrupt enable register and its BITs */
>> +#define SPRD_IEN 0x0010
>> +#define SPRD_IEN_RX_FULL BIT(0)
>> +#define SPRD_IEN_TX_EMPTY BIT(1)
>> +#define SPRD_IEN_BREAK_DETECT BIT(7)
>> +#define SPRD_IEN_TIMEOUT BIT(13)
>> +
>> +/* interrupt clear register */
>> +#define SPRD_ICLR 0x0014
>> +
>> +/* line control register */
>> +#define SPRD_LCR 0x0018
>> +#define SPRD_LCR_STOP_1BIT 0x10
>> +#define SPRD_LCR_STOP_2BIT 0x30
>> +#define SPRD_LCR_DATA_LEN (BIT(2) | BIT(3))
>> +#define SPRD_LCR_DATA_LEN5 0x0
>> +#define SPRD_LCR_DATA_LEN6 0x4
>> +#define SPRD_LCR_DATA_LEN7 0x8
>> +#define SPRD_LCR_DATA_LEN8 0xc
>> +#define SPRD_LCR_PARITY (BIT(0) | BIT(1))
>> +#define SPRD_LCR_PARITY_EN 0x2
>> +#define SPRD_LCR_EVEN_PAR 0x0
>> +#define SPRD_LCR_ODD_PAR 0x1
>> +
>> +/* control register 1 */
>> +#define SPRD_CTL1 0x001C
>> +#define RX_HW_FLOW_CTL_THLD BIT(6)
>> +#define RX_HW_FLOW_CTL_EN BIT(7)
>> +#define TX_HW_FLOW_CTL_EN BIT(8)
>> +
>> +/* fifo threshold register */
>> +#define SPRD_CTL2 0x0020
>> +#define THLD_TX_EMPTY 0x40
>> +#define THLD_RX_FULL 0x40
>> +
>> +/* config baud rate register */
>> +#define SPRD_CLKD0 0x0024
>> +#define SPRD_CLKD1 0x0028
>> +
>> +/* interrupt mask status register */
>> +#define SPRD_IMSR 0x002C
>> +#define SPRD_IMSR_RX_FIFO_FULL BIT(0)
>> +#define SPRD_IMSR_TX_FIFO_EMPTY BIT(1)
>> +#define SPRD_IMSR_BREAK_DETECT BIT(7)
>> +#define SPRD_IMSR_TIMEOUT BIT(13)
>> +
>> +struct reg_backup {
>> + uint32_t ien;
>> + uint32_t ctrl0;
>> + uint32_t ctrl1;
>> + uint32_t ctrl2;
>> + uint32_t clkd0;
>> + uint32_t clkd1;
>> + uint32_t dspwait;
>> +};
>> +
>> +struct sprd_uart_port {
>> + struct uart_port port;
>> + struct reg_backup reg_bak;
>> + char name[16];
>> +};
>> +
>> +static struct sprd_uart_port *sprd_port[UART_NR_MAX] = { NULL };
>> +
>> +static inline unsigned int serial_in(struct uart_port *port, int offset)
>> +{
>> + return readl_relaxed(port->membase + offset);
>> +}
>> +
>> +static inline void serial_out(struct uart_port *port, int offset, int value)
>> +{
>> + writel_relaxed(value, port->membase + offset);
>> +}
>> +
>> +static unsigned int sprd_tx_empty(struct uart_port *port)
>> +{
>> + if (serial_in(port, SPRD_STS1) & 0xff00)
>> + return 0;
>> + else
>> + return TIOCSER_TEMT;
>> +}
>> +
>> +static unsigned int sprd_get_mctrl(struct uart_port *port)
>> +{
>> + return TIOCM_DSR | TIOCM_CTS;
>> +}
>> +
>> +static void sprd_set_mctrl(struct uart_port *port, unsigned int mctrl)
>> +{
>> + /* nothing to do */
>> +}
>> +
>> +static void sprd_stop_tx(struct uart_port *port)
>> +{
>> + unsigned int ien, iclr;
>> +
>> + iclr = serial_in(port, SPRD_ICLR);
>> + ien = serial_in(port, SPRD_IEN);
>> +
>> + iclr |= SPRD_IEN_TX_EMPTY;
>> + ien &= ~SPRD_IEN_TX_EMPTY;
>> +
>> + serial_out(port, SPRD_ICLR, iclr);
>> + serial_out(port, SPRD_IEN, ien);
>> +}
>> +
>> +static void sprd_start_tx(struct uart_port *port)
>> +{
>> + unsigned int ien;
>> +
>> + ien = serial_in(port, SPRD_IEN);
>> + if (!(ien & SPRD_IEN_TX_EMPTY)) {
>> + ien |= SPRD_IEN_TX_EMPTY;
>> + serial_out(port, SPRD_IEN, ien);
>> + }
>> +}
>> +
>> +static void sprd_stop_rx(struct uart_port *port)
>> +{
>> + unsigned int ien, iclr;
>> +
>> + iclr = serial_in(port, SPRD_ICLR);
>> + ien = serial_in(port, SPRD_IEN);
>> +
>> + ien &= ~(SPRD_IEN_RX_FULL | SPRD_IEN_BREAK_DETECT);
>> + iclr |= SPRD_IEN_RX_FULL | SPRD_IEN_BREAK_DETECT;
>> +
>> + serial_out(port, SPRD_IEN, ien);
>> + serial_out(port, SPRD_ICLR, iclr);
>> +}
>> +
>> +/* The Sprd serial does not support this function. */
>> +static void sprd_break_ctl(struct uart_port *port, int break_state)
>> +{
>> + /* nothing to do */
>> +}
>> +
>> +static inline int handle_lsr_errors(struct uart_port *port,
>> + unsigned int *flag,
>> + unsigned int *lsr)
>> +{
>> + int ret = 0;
>> +
>> + /* statistics */
>> + if (*lsr & SPRD_LSR_BI) {
>> + *lsr &= ~(SPRD_LSR_FE | SPRD_LSR_PE);
>> + port->icount.brk++;
>> + ret = uart_handle_break(port);
>> + if (ret)
>> + return ret;
>> + } else if (*lsr & SPRD_LSR_PE)
>> + port->icount.parity++;
>> + else if (*lsr & SPRD_LSR_FE)
>> + port->icount.frame++;
>> + if (*lsr & SPRD_LSR_OE)
>> + port->icount.overrun++;
>> +
>> + /* mask off conditions which should be ignored */
>> + *lsr &= port->read_status_mask;
>> + if (*lsr & SPRD_LSR_BI)
>> + *flag = TTY_BREAK;
>> + else if (*lsr & SPRD_LSR_PE)
>> + *flag = TTY_PARITY;
>> + else if (*lsr & SPRD_LSR_FE)
>> + *flag = TTY_FRAME;
>> +
>> + return ret;
>> +}
>> +
>> +static inline void sprd_rx(int irq, void *dev_id)
>> +{
>> + struct uart_port *port = dev_id;
>> + struct tty_port *tty = &port->state->port;
>> + unsigned int ch, flag, lsr, max_count = SPRD_TIMEOUT;
>> +
>> + while ((serial_in(port, SPRD_STS1) & 0x00ff) && max_count--) {
>> + lsr = serial_in(port, SPRD_LSR);
>> + ch = serial_in(port, SPRD_RXD);
>> + flag = TTY_NORMAL;
>> + port->icount.rx++;
>> +
>> + if (lsr & (SPRD_LSR_BI | SPRD_LSR_PE
>> + | SPRD_LSR_FE | SPRD_LSR_OE))
>> + if (handle_lsr_errors(port, &lsr, &flag))
>> + continue;
>> + if (uart_handle_sysrq_char(port, ch))
>> + continue;
>> +
>> + uart_insert_char(port, lsr, SPRD_LSR_OE, ch, flag);
>> + }
>> +
>> + tty_flip_buffer_push(tty);
>> +}
>> +
>> +static inline void sprd_tx(int irq, void *dev_id)
>> +{
>> + struct uart_port *port = dev_id;
>> + struct circ_buf *xmit = &port->state->xmit;
>> + int count;
>> +
>> + if (port->x_char) {
>> + serial_out(port, SPRD_TXD, port->x_char);
>> + port->icount.tx++;
>> + port->x_char = 0;
>> + return;
>> + }
>> +
>> + if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
>> + sprd_stop_tx(port);
>> + return;
>> + }
>> +
>> + count = THLD_TX_EMPTY;
>> + do {
>> + serial_out(port, SPRD_TXD, xmit->buf[xmit->tail]);
>> + xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
>> + port->icount.tx++;
>> + if (uart_circ_empty(xmit))
>> + break;
>> + } while (--count > 0);
>> +
>> + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
>> + uart_write_wakeup(port);
>> +
>> + if (uart_circ_empty(xmit))
>> + sprd_stop_tx(port);
>> +}
>> +
>> +/* this handles the interrupt from one port */
>> +static irqreturn_t sprd_handle_irq(int irq, void *dev_id)
>> +{
>> + struct uart_port *port = (struct uart_port *)dev_id;
>> + unsigned int ims;
> Why does your isr not have to take port->lock ?
The original consideration is the registers are accessed by isr only.
Interrupt will not be nested because of gic chip driver protection.
So there is not other thread will race on it.
Does this make sense?
>
>> + ims = serial_in(port, SPRD_IMSR);
>> +
>> + if (!ims)
>> + return IRQ_NONE;
>> +
>> + serial_out(port, SPRD_ICLR, ~0);
>> +
>> + if (ims & (SPRD_IMSR_RX_FIFO_FULL |
>> + SPRD_IMSR_BREAK_DETECT | SPRD_IMSR_TIMEOUT))
>> + sprd_rx(irq, port);
>> +
>> + if (ims & SPRD_IMSR_TX_FIFO_EMPTY)
>> + sprd_tx(irq, port);
>> +
>> + return IRQ_HANDLED;
>> +}
>> +
>> +static int sprd_startup(struct uart_port *port)
>> +{
>> + int ret = 0;
>> + unsigned int ien, ctrl1;
>> + unsigned int timeout;
>> + struct sprd_uart_port *sp;
>> +
>> + serial_out(port, SPRD_CTL2, ((THLD_TX_EMPTY << 8) | THLD_RX_FULL));
>> +
>> + /* clear rx fifo */
>> + timeout = SPRD_TIMEOUT;
>> + while (timeout-- && serial_in(port, SPRD_STS1) & 0x00ff)
>> + serial_in(port, SPRD_RXD);
>> +
>> + /* clear tx fifo */
>> + timeout = SPRD_TIMEOUT;
>> + while (timeout-- && serial_in(port, SPRD_STS1) & 0xff00)
>> + cpu_relax();
>> +
>> + /* clear interrupt */
>> + serial_out(port, SPRD_IEN, 0x0);
>> + serial_out(port, SPRD_ICLR, ~0);
>> +
>> + /* allocate irq */
>> + sp = container_of(port, struct sprd_uart_port, port);
>> + snprintf(sp->name, sizeof(sp->name), "sprd_serial%d", port->line);
>> + ret = devm_request_irq(port->dev, port->irq, sprd_handle_irq,
>> + IRQF_SHARED, sp->name, port);
>> + if (ret) {
>> + dev_err(port->dev, "fail to request serial irq %d, ret=%d\n",
>> + port->irq, ret);
>> + return ret;
>> + }
>> + ctrl1 = serial_in(port, SPRD_CTL1);
>> + ctrl1 |= 0x3e00 | THLD_RX_FULL;
>> + serial_out(port, SPRD_CTL1, ctrl1);
>> +
>> + /* enable interrupt */
>> + spin_lock(&port->lock);
>> + ien = serial_in(port, SPRD_IEN);
>> + ien |= SPRD_IEN_RX_FULL | SPRD_IEN_BREAK_DETECT | SPRD_IEN_TIMEOUT;
>> + serial_out(port, SPRD_IEN, ien);
>> + spin_unlock(&port->lock);
>> +
>> + return 0;
>> +}
>> +
>> +static void sprd_shutdown(struct uart_port *port)
>> +{
>> + serial_out(port, SPRD_IEN, 0x0);
>> + serial_out(port, SPRD_ICLR, ~0);
>> + devm_free_irq(port->dev, port->irq, port);
>> +}
>> +
>> +static void sprd_set_termios(struct uart_port *port,
>> + struct ktermios *termios,
>> + struct ktermios *old)
>> +{
>> + unsigned int baud, quot;
>> + unsigned int lcr, fc;
>> +
>> + /* ask the core to calculate the divisor for us */
>> + baud = uart_get_baud_rate(port, termios, old, 1200, 3000000);
>> +
>> + quot = (unsigned int)((port->uartclk + baud / 2) / baud);
>> +
>> + /* set data length */
>> + lcr = serial_in(port, SPRD_LCR);
>> + lcr &= ~SPRD_LCR_DATA_LEN;
>> + switch (termios->c_cflag & CSIZE) {
>> + case CS5:
>> + lcr |= SPRD_LCR_DATA_LEN5;
>> + break;
>> + case CS6:
>> + lcr |= SPRD_LCR_DATA_LEN6;
>> + break;
>> + case CS7:
>> + lcr |= SPRD_LCR_DATA_LEN7;
>> + break;
>> + case CS8:
>> + default:
>> + lcr |= SPRD_LCR_DATA_LEN8;
>> + break;
>> + }
>> +
>> + /* calculate stop bits */
>> + lcr &= ~(SPRD_LCR_STOP_1BIT | SPRD_LCR_STOP_2BIT);
>> + if (termios->c_cflag & CSTOPB)
>> + lcr |= SPRD_LCR_STOP_2BIT;
>> + else
>> + lcr |= SPRD_LCR_STOP_1BIT;
>> +
>> + /* calculate parity */
>> + lcr &= ~SPRD_LCR_PARITY;
>> + termios->c_cflag &= ~CMSPAR; /* no support mark/space */
>> + if (termios->c_cflag & PARENB) {
>> + lcr |= SPRD_LCR_PARITY_EN;
>> + if (termios->c_cflag & PARODD)
>> + lcr |= SPRD_LCR_ODD_PAR;
>> + else
>> + lcr |= SPRD_LCR_EVEN_PAR;
>> + }
>> +
>> + /* change the port state. */
> ^^^^^^^^^^^^^^^^^^^^^^
>
> This means you should be taking the port->lock here... (and disabling
> local interrupts if your isr takes the port->lock)
Yes, I think you are right.
>
>> + /* update the per-port timeout */
>> + uart_update_timeout(port, termios->c_cflag, baud);
>> +
>> + port->read_status_mask = SPRD_LSR_OE;
>> + if (termios->c_iflag & INPCK)
>> + port->read_status_mask |= SPRD_LSR_FE | SPRD_LSR_PE;
>> + if (termios->c_iflag & (BRKINT | PARMRK))
>> + port->read_status_mask |= SPRD_LSR_BI;
>> +
>> + /* characters to ignore */
>> + port->ignore_status_mask = 0;
>> + if (termios->c_iflag & IGNPAR)
>> + port->ignore_status_mask |= SPRD_LSR_PE | SPRD_LSR_FE;
>> + if (termios->c_iflag & IGNBRK) {
>> + port->ignore_status_mask |= SPRD_LSR_BI;
>> + /*
>> + * If we're ignoring parity and break indicators,
>> + * ignore overruns too (for real raw support).
>> + */
>> + if (termios->c_iflag & IGNPAR)
>> + port->ignore_status_mask |= SPRD_LSR_OE;
>> + }
>> +
>> + /* flow control */
>> + fc = serial_in(port, SPRD_CTL1);
>> + fc &= ~(RX_HW_FLOW_CTL_THLD | RX_HW_FLOW_CTL_EN | TX_HW_FLOW_CTL_EN);
>> + if (termios->c_cflag & CRTSCTS) {
>> + fc |= RX_HW_FLOW_CTL_THLD;
>> + fc |= RX_HW_FLOW_CTL_EN;
>> + fc |= TX_HW_FLOW_CTL_EN;
>> + }
>> +
>> + /* clock divider bit0~bit15 */
>> + serial_out(port, SPRD_CLKD0, quot & 0xffff);
>> +
>> + /* clock divider bit16~bit20 */
>> + serial_out(port, SPRD_CLKD1, (quot & 0x1f0000) >> 16);
>> + serial_out(port, SPRD_LCR, lcr);
>> + fc |= 0x3e00 | THLD_RX_FULL;
>> + serial_out(port, SPRD_CTL1, fc);
> and dropping it here.
>
>> + /* Don't rewrite B0 */
>> + if (tty_termios_baud_rate(termios))
>> + tty_termios_encode_baud_rate(termios, baud, baud);
>> +}
>> +
>> +static const char *sprd_type(struct uart_port *port)
>> +{
>> + return "SPX";
>> +}
>> +
>> +static void sprd_release_port(struct uart_port *port)
>> +{
>> + /* nothing to do */
>> +}
>> +
>> +static int sprd_request_port(struct uart_port *port)
>> +{
>> + return 0;
>> +}
>> +
>> +static void sprd_config_port(struct uart_port *port, int flags)
>> +{
>> + if (flags & UART_CONFIG_TYPE)
>> + port->type = PORT_SPRD;
>> +}
>> +
>> +static int sprd_verify_port(struct uart_port *port,
>> + struct serial_struct *ser)
>> +{
>> + if (ser->type != PORT_SPRD)
>> + return -EINVAL;
>> + if (port->irq != ser->irq)
>> + return -EINVAL;
>> + return 0;
>> +}
>> +
>> +static struct uart_ops serial_sprd_ops = {
>> + .tx_empty = sprd_tx_empty,
>> + .get_mctrl = sprd_get_mctrl,
>> + .set_mctrl = sprd_set_mctrl,
>> + .stop_tx = sprd_stop_tx,
>> + .start_tx = sprd_start_tx,
>> + .stop_rx = sprd_stop_rx,
>> + .break_ctl = sprd_break_ctl,
>> + .startup = sprd_startup,
>> + .shutdown = sprd_shutdown,
>> + .set_termios = sprd_set_termios,
>> + .type = sprd_type,
>> + .release_port = sprd_release_port,
>> + .request_port = sprd_request_port,
>> + .config_port = sprd_config_port,
>> + .verify_port = sprd_verify_port,
>> +};
>> +
>> +#ifdef CONFIG_SERIAL_SPRD_CONSOLE
>> +static inline void wait_for_xmitr(struct uart_port *port)
>> +{
>> + unsigned int status, tmout = 10000;
>> +
>> + /* wait up to 10ms for the character(s) to be sent */
>> + do {
>> + status = serial_in(port, SPRD_STS1);
>> + if (--tmout == 0)
>> + break;
>> + udelay(1);
>> + } while (status & 0xff00);
>> +}
>> +
>> +static void sprd_console_putchar(struct uart_port *port, int ch)
>> +{
>> + wait_for_xmitr(port);
>> + serial_out(port, SPRD_TXD, ch);
>> +}
>> +
>> +static void sprd_console_write(struct console *co, const char *s,
>> + unsigned int count)
>> +{
>> + struct uart_port *port = &sprd_port[co->index]->port;
>> + int ien;
>> + int locked = 1;
>> +
>> + if (oops_in_progress)
>> + locked = spin_trylock(&port->lock);
>> + else
>> + spin_lock(&port->lock);
> If you do need to take the port->lock in your isr, then you need to
> disable local irq here.
You mean to use spin_lock_irqsave()?
We do disable irq below....
>
>> + /* save the IEN then disable the interrupts */
>> + ien = serial_in(port, SPRD_IEN);
>> + serial_out(port, SPRD_IEN, 0x0);
Here, we disable port IEN register.
>> +
>> + uart_console_write(port, s, count, sprd_console_putchar);
>> +
>> + /* wait for transmitter to become empty and restore the IEN */
>> + wait_for_xmitr(port);
>> + serial_out(port, SPRD_IEN, ien);
>> + if (locked)
>> + spin_unlock(&port->lock);
>> +}
>> +
>> +static int __init sprd_console_setup(struct console *co, char *options)
>> +{
>> + struct uart_port *port;
>> + int baud = 115200;
>> + int bits = 8;
>> + int parity = 'n';
>> + int flow = 'n';
>> +
>> + if (co->index >= UART_NR_MAX || co->index < 0)
>> + co->index = 0;
>> +
>> + port = &sprd_port[co->index]->port;
>> + if (port == NULL) {
>> + pr_info("serial port %d not yet initialized\n", co->index);
>> + return -ENODEV;
>> + }
>> + if (options)
>> + uart_parse_options(options, &baud, &parity, &bits, &flow);
>> +
>> + return uart_set_options(port, co, baud, parity, bits, flow);
>> +}
>> +
>> +static struct uart_driver sprd_uart_driver;
>> +static struct console sprd_console = {
>> + .name = SPRD_TTY_NAME,
>> + .write = sprd_console_write,
>> + .device = uart_console_device,
>> + .setup = sprd_console_setup,
>> + .flags = CON_PRINTBUFFER,
>> + .index = -1,
>> + .data = &sprd_uart_driver,
>> +};
>> +
>> +#define SPRD_CONSOLE (&sprd_console)
>> +
>> +/* Support for earlycon */
>> +static void sprd_putc(struct uart_port *port, int c)
>> +{
>> + unsigned int timeout = SPRD_TIMEOUT;
>> +
>> + while (timeout-- &&
>> + !(readl(port->membase + SPRD_LSR) & SPRD_LSR_TX_OVER))
>> + cpu_relax();
>> +
>> + writeb(c, port->membase + SPRD_TXD);
>> +}
>> +
>> +static void sprd_early_write(struct console *con, const char *s,
>> + unsigned n)
>> +{
>> + struct earlycon_device *dev = con->data;
>> +
>> + uart_console_write(&dev->port, s, n, sprd_putc);
>> +}
>> +
>> +static int __init sprd_early_console_setup(
>> + struct earlycon_device *device,
>> + const char *opt)
>> +{
>> + if (!device->port.membase)
>> + return -ENODEV;
>> +
>> + device->con->write = sprd_early_write;
>> + return 0;
>> +}
>> +
>> +EARLYCON_DECLARE(sprd_serial, sprd_early_console_setup);
>> +OF_EARLYCON_DECLARE(sprd_serial, "sprd,sc9836-uart",
>> + sprd_early_console_setup);
>> +
>> +#else /* !CONFIG_SERIAL_SPRD_CONSOLE */
>> +#define SPRD_CONSOLE NULL
>> +#endif
>> +
>> +static struct uart_driver sprd_uart_driver = {
>> + .owner = THIS_MODULE,
>> + .driver_name = "sprd_serial",
>> + .dev_name = SPRD_TTY_NAME,
>> + .major = 0,
>> + .minor = 0,
>> + .nr = UART_NR_MAX,
>> + .cons = SPRD_CONSOLE,
>> +};
>> +
>> +static int sprd_probe(struct platform_device *pdev)
>> +{
>> + struct resource *res;
>> + struct device_node *np = pdev->dev.of_node;
>> + struct uart_port *up;
>> + struct clk *clk;
>> + int irq;
>> +
>> + if (np)
>> + pdev->id = of_alias_get_id(np, "serial");
>> +
>> + if (pdev->id < 0 || pdev->id >= UART_NR_MAX) {
>> + dev_err(&pdev->dev, "does not support id %d\n", pdev->id);
>> + return -ENXIO;
>> + }
>> +
>> + sprd_port[pdev->id] = devm_kzalloc(&pdev->dev,
>> + sizeof(*sprd_port[pdev->id]), GFP_KERNEL);
>> + if (!sprd_port[pdev->id])
>> + return -ENOMEM;
>> +
>> + up = &sprd_port[pdev->id]->port;
>> + up->dev = &pdev->dev;
>> + up->line = pdev->id;
>> + up->type = PORT_SPRD;
>> + up->iotype = SERIAL_IO_PORT;
>> + up->uartclk = SPRD_DEF_RATE;
>> + up->fifosize = SPRD_FIFO_SIZE;
>> + up->ops = &serial_sprd_ops;
>> + up->flags = ASYNC_BOOT_AUTOCONF;
>> +
>> + clk = devm_clk_get(&pdev->dev, NULL);
>> + if (!IS_ERR(clk))
>> + up->uartclk = clk_get_rate(clk);
>> +
>> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> + if (!res) {
>> + dev_err(&pdev->dev, "not provide mem resource\n");
>> + return -ENODEV;
>> + }
>> + up->mapbase = res->start;
>> + up->membase = devm_ioremap_resource(&pdev->dev, res);
>> + if (IS_ERR(up->membase))
>> + return PTR_ERR(up->membase);
>> +
>> + irq = platform_get_irq(pdev, 0);
>> + if (irq < 0) {
>> + dev_err(&pdev->dev, "not provide irq resource\n");
>> + return -ENODEV;
>> + }
>> + up->irq = irq;
>> +
>> + platform_set_drvdata(pdev, up);
>> +
>> + return uart_add_one_port(&sprd_uart_driver, up);
>> +}
>> +
>> +static int sprd_remove(struct platform_device *dev)
>> +{
>> + struct uart_port *up = platform_get_drvdata(dev);
>> +
>> + return uart_remove_one_port(&sprd_uart_driver, up);
>> +}
>> +
>> +static int sprd_suspend(struct device *dev)
>> +{
>> + int id = to_platform_device(dev)->id;
>> + struct uart_port *port = &sprd_port[id]->port;
>> + struct reg_backup *reg_bak = &sprd_port[id]->reg_bak;
>> +
>> + reg_bak->ien = serial_in(port, SPRD_IEN);
>> + reg_bak->ctrl0 = serial_in(port, SPRD_LCR);
>> + reg_bak->ctrl1 = serial_in(port, SPRD_CTL1);
>> + reg_bak->ctrl2 = serial_in(port, SPRD_CTL2);
>> + reg_bak->clkd0 = serial_in(port, SPRD_CLKD0);
>> + reg_bak->clkd1 = serial_in(port, SPRD_CLKD1);
> Why are you saving and restoring these register states
> across suspend/resume?
>
> The serial core calls your set_termios() handler upon
> resume (either for the console or if a tty is open)
> so you should be reprogramming the hardware there
> based on the termios settings.
We'll try to address it in V6.
Thanks,
Orson
>
> Regards,
> Peter Hurley
>> +
>> + uart_suspend_port(&sprd_uart_driver, port);
>> +
>> + return 0;
>> +}
>> +
>> +static int sprd_resume(struct device *dev)
>> +{
>> + int id = to_platform_device(dev)->id;
>> + struct uart_port *port = &sprd_port[id]->port;
>> + struct reg_backup *reg_bak = &sprd_port[id]->reg_bak;
>> +
>> + serial_out(port, SPRD_LCR, reg_bak->ctrl0);
>> + serial_out(port, SPRD_CTL1, reg_bak->ctrl1);
>> + serial_out(port, SPRD_CTL2, reg_bak->ctrl2);
>> + serial_out(port, SPRD_CLKD0, reg_bak->clkd0);
>> + serial_out(port, SPRD_CLKD1, reg_bak->clkd1);
>> + serial_out(port, SPRD_IEN, reg_bak->ien);
>> +
>> + uart_resume_port(&sprd_uart_driver, port);
>> +
>> + return 0;
>> +}
>> +
>> +static const struct of_device_id serial_ids[] = {
>> + {.compatible = "sprd,sc9836-uart",},
>> + {}
>> +};
>> +
>> +static SIMPLE_DEV_PM_OPS(sprd_pm_ops, sprd_suspend, sprd_resume);
>> +
>> +static struct platform_driver sprd_platform_driver = {
>> + .probe = sprd_probe,
>> + .remove = sprd_remove,
>> + .driver = {
>> + .name = "sprd_serial",
>> + .of_match_table = of_match_ptr(serial_ids),
>> + .pm = &sprd_pm_ops,
>> + },
>> +};
>> +
>> +static int __init sprd_serial_init(void)
>> +{
>> + int ret = 0;
>> +
>> + ret = uart_register_driver(&sprd_uart_driver);
>> + if (ret)
>> + return ret;
>> +
>> + ret = platform_driver_register(&sprd_platform_driver);
>> + if (ret)
>> + uart_unregister_driver(&sprd_uart_driver);
>> +
>> + return ret;
>> +}
>> +
>> +static void __exit sprd_serial_exit(void)
>> +{
>> + platform_driver_unregister(&sprd_platform_driver);
>> + uart_unregister_driver(&sprd_uart_driver);
>> +}
>> +
>> +module_init(sprd_serial_init);
>> +module_exit(sprd_serial_exit);
>> +
>> +MODULE_LICENSE("GPL v2");
>> +MODULE_DESCRIPTION("Spreadtrum SoC serial driver series");
>> diff --git a/include/uapi/linux/serial_core.h b/include/uapi/linux/serial_core.h
>> index c172180..7e6eb39 100644
>> --- a/include/uapi/linux/serial_core.h
>> +++ b/include/uapi/linux/serial_core.h
>> @@ -248,4 +248,7 @@
>> /* MESON */
>> #define PORT_MESON 109
>>
>> +/* SPRD SERIAL */
>> +#define PORT_SPRD 110
>> +
>> #endif /* _UAPILINUX_SERIAL_CORE_H */
>>
^ permalink raw reply [flat|nested] 81+ messages in thread* [PATCH v5 5/5] tty/serial: Add Spreadtrum sc9836-uart driver support
@ 2015-01-20 12:11 ` Orson Zhai
0 siblings, 0 replies; 81+ messages in thread
From: Orson Zhai @ 2015-01-20 12:11 UTC (permalink / raw)
To: linux-arm-kernel
Hi, Peter,
Thank you for reviewing our code!
Some discussion below.
On 2015?01?16? 23:20, Peter Hurley wrote:
> On 01/16/2015 05:00 AM, Chunyan Zhang wrote:
>> Add a full sc9836-uart driver for SC9836 SoC which is based on the
>> spreadtrum sharkl64 platform.
>> This driver also support earlycon.
>> This patch also replaced the spaces between the macros and their
>> values with the tabs in serial_core.h
> The locking doesn't look correct. Specific notations below.
>
>> Signed-off-by: Chunyan Zhang <chunyan.zhang@spreadtrum.com>
>> Signed-off-by: Orson Zhai <orson.zhai@spreadtrum.com>
>> Originally-by: Lanqing Liu <lanqing.liu@spreadtrum.com>
>> ---
>> drivers/tty/serial/Kconfig | 18 +
>> drivers/tty/serial/Makefile | 1 +
>> drivers/tty/serial/sprd_serial.c | 772 ++++++++++++++++++++++++++++++++++++++
>> include/uapi/linux/serial_core.h | 3 +
>> 4 files changed, 794 insertions(+)
>> create mode 100644 drivers/tty/serial/sprd_serial.c
>>
>> diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
>> index c79b43c..969d3cd 100644
>> --- a/drivers/tty/serial/Kconfig
>> +++ b/drivers/tty/serial/Kconfig
>> @@ -1577,6 +1577,24 @@ config SERIAL_MEN_Z135
>> This driver can also be build as a module. If so, the module will be called
>> men_z135_uart.ko
>>
>> +config SERIAL_SPRD
>> + tristate "Support for SPRD serial"
>> + depends on ARCH_SPRD
>> + select SERIAL_CORE
>> + help
>> + This enables the driver for the Spreadtrum's serial.
>> +
>> +config SERIAL_SPRD_CONSOLE
>> + bool "SPRD UART console support"
>> + depends on SERIAL_SPRD=y
>> + select SERIAL_CORE_CONSOLE
>> + select SERIAL_EARLYCON
>> + help
>> + Support for early debug console using Spreadtrum's serial. This enables
>> + the console before standard serial driver is probed. This is enabled
>> + with "earlycon" on the kernel command line. The console is
>> + enabled when early_param is processed.
>> +
>> endmenu
>>
>> config SERIAL_MCTRL_GPIO
>> diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile
>> index 9a548ac..4801aca 100644
>> --- a/drivers/tty/serial/Makefile
>> +++ b/drivers/tty/serial/Makefile
>> @@ -93,6 +93,7 @@ obj-$(CONFIG_SERIAL_ARC) += arc_uart.o
>> obj-$(CONFIG_SERIAL_RP2) += rp2.o
>> obj-$(CONFIG_SERIAL_FSL_LPUART) += fsl_lpuart.o
>> obj-$(CONFIG_SERIAL_MEN_Z135) += men_z135_uart.o
>> +obj-$(CONFIG_SERIAL_SPRD) += sprd_serial.o
>>
>> # GPIOLIB helpers for modem control lines
>> obj-$(CONFIG_SERIAL_MCTRL_GPIO) += serial_mctrl_gpio.o
>> diff --git a/drivers/tty/serial/sprd_serial.c b/drivers/tty/serial/sprd_serial.c
>> new file mode 100644
>> index 0000000..81839e4
>> --- /dev/null
>> +++ b/drivers/tty/serial/sprd_serial.c
>> @@ -0,0 +1,772 @@
>> +/*
>> + * Copyright (C) 2012 Spreadtrum Communications Inc.
>> + *
>> + * This software is licensed under the terms of the GNU General Public
>> + * License version 2, as published by the Free Software Foundation, and
>> + * may be copied, distributed, and modified under those terms.
>> + *
>> + * This program is distributed in the hope that it will be useful,
>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
>> + * GNU General Public License for more details.
>> + */
>> +
>> +#include <linux/clk.h>
>> +#include <linux/console.h>
>> +#include <linux/delay.h>
>> +#include <linux/io.h>
>> +#include <linux/ioport.h>
>> +#include <linux/kernel.h>
>> +#include <linux/module.h>
>> +#include <linux/of.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/serial_core.h>
>> +#include <linux/serial.h>
>> +#include <linux/slab.h>
>> +#include <linux/tty.h>
>> +#include <linux/tty_flip.h>
>> +
>> +/* device name */
>> +#define UART_NR_MAX 8
>> +#define SPRD_TTY_NAME "ttySPX"
>> +#define SPRD_FIFO_SIZE 128
>> +#define SPRD_DEF_RATE 26000000
>> +#define SPRD_TIMEOUT 2048
>> +
>> +/* the offset of serial registers and BITs for them */
>> +/* data registers */
>> +#define SPRD_TXD 0x0000
>> +#define SPRD_RXD 0x0004
>> +
>> +/* line status register and its BITs */
>> +#define SPRD_LSR 0x0008
>> +#define SPRD_LSR_OE BIT(4)
>> +#define SPRD_LSR_FE BIT(3)
>> +#define SPRD_LSR_PE BIT(2)
>> +#define SPRD_LSR_BI BIT(7)
>> +#define SPRD_LSR_TX_OVER BIT(15)
>> +
>> +/* data number in TX and RX fifo */
>> +#define SPRD_STS1 0x000C
>> +
>> +/* interrupt enable register and its BITs */
>> +#define SPRD_IEN 0x0010
>> +#define SPRD_IEN_RX_FULL BIT(0)
>> +#define SPRD_IEN_TX_EMPTY BIT(1)
>> +#define SPRD_IEN_BREAK_DETECT BIT(7)
>> +#define SPRD_IEN_TIMEOUT BIT(13)
>> +
>> +/* interrupt clear register */
>> +#define SPRD_ICLR 0x0014
>> +
>> +/* line control register */
>> +#define SPRD_LCR 0x0018
>> +#define SPRD_LCR_STOP_1BIT 0x10
>> +#define SPRD_LCR_STOP_2BIT 0x30
>> +#define SPRD_LCR_DATA_LEN (BIT(2) | BIT(3))
>> +#define SPRD_LCR_DATA_LEN5 0x0
>> +#define SPRD_LCR_DATA_LEN6 0x4
>> +#define SPRD_LCR_DATA_LEN7 0x8
>> +#define SPRD_LCR_DATA_LEN8 0xc
>> +#define SPRD_LCR_PARITY (BIT(0) | BIT(1))
>> +#define SPRD_LCR_PARITY_EN 0x2
>> +#define SPRD_LCR_EVEN_PAR 0x0
>> +#define SPRD_LCR_ODD_PAR 0x1
>> +
>> +/* control register 1 */
>> +#define SPRD_CTL1 0x001C
>> +#define RX_HW_FLOW_CTL_THLD BIT(6)
>> +#define RX_HW_FLOW_CTL_EN BIT(7)
>> +#define TX_HW_FLOW_CTL_EN BIT(8)
>> +
>> +/* fifo threshold register */
>> +#define SPRD_CTL2 0x0020
>> +#define THLD_TX_EMPTY 0x40
>> +#define THLD_RX_FULL 0x40
>> +
>> +/* config baud rate register */
>> +#define SPRD_CLKD0 0x0024
>> +#define SPRD_CLKD1 0x0028
>> +
>> +/* interrupt mask status register */
>> +#define SPRD_IMSR 0x002C
>> +#define SPRD_IMSR_RX_FIFO_FULL BIT(0)
>> +#define SPRD_IMSR_TX_FIFO_EMPTY BIT(1)
>> +#define SPRD_IMSR_BREAK_DETECT BIT(7)
>> +#define SPRD_IMSR_TIMEOUT BIT(13)
>> +
>> +struct reg_backup {
>> + uint32_t ien;
>> + uint32_t ctrl0;
>> + uint32_t ctrl1;
>> + uint32_t ctrl2;
>> + uint32_t clkd0;
>> + uint32_t clkd1;
>> + uint32_t dspwait;
>> +};
>> +
>> +struct sprd_uart_port {
>> + struct uart_port port;
>> + struct reg_backup reg_bak;
>> + char name[16];
>> +};
>> +
>> +static struct sprd_uart_port *sprd_port[UART_NR_MAX] = { NULL };
>> +
>> +static inline unsigned int serial_in(struct uart_port *port, int offset)
>> +{
>> + return readl_relaxed(port->membase + offset);
>> +}
>> +
>> +static inline void serial_out(struct uart_port *port, int offset, int value)
>> +{
>> + writel_relaxed(value, port->membase + offset);
>> +}
>> +
>> +static unsigned int sprd_tx_empty(struct uart_port *port)
>> +{
>> + if (serial_in(port, SPRD_STS1) & 0xff00)
>> + return 0;
>> + else
>> + return TIOCSER_TEMT;
>> +}
>> +
>> +static unsigned int sprd_get_mctrl(struct uart_port *port)
>> +{
>> + return TIOCM_DSR | TIOCM_CTS;
>> +}
>> +
>> +static void sprd_set_mctrl(struct uart_port *port, unsigned int mctrl)
>> +{
>> + /* nothing to do */
>> +}
>> +
>> +static void sprd_stop_tx(struct uart_port *port)
>> +{
>> + unsigned int ien, iclr;
>> +
>> + iclr = serial_in(port, SPRD_ICLR);
>> + ien = serial_in(port, SPRD_IEN);
>> +
>> + iclr |= SPRD_IEN_TX_EMPTY;
>> + ien &= ~SPRD_IEN_TX_EMPTY;
>> +
>> + serial_out(port, SPRD_ICLR, iclr);
>> + serial_out(port, SPRD_IEN, ien);
>> +}
>> +
>> +static void sprd_start_tx(struct uart_port *port)
>> +{
>> + unsigned int ien;
>> +
>> + ien = serial_in(port, SPRD_IEN);
>> + if (!(ien & SPRD_IEN_TX_EMPTY)) {
>> + ien |= SPRD_IEN_TX_EMPTY;
>> + serial_out(port, SPRD_IEN, ien);
>> + }
>> +}
>> +
>> +static void sprd_stop_rx(struct uart_port *port)
>> +{
>> + unsigned int ien, iclr;
>> +
>> + iclr = serial_in(port, SPRD_ICLR);
>> + ien = serial_in(port, SPRD_IEN);
>> +
>> + ien &= ~(SPRD_IEN_RX_FULL | SPRD_IEN_BREAK_DETECT);
>> + iclr |= SPRD_IEN_RX_FULL | SPRD_IEN_BREAK_DETECT;
>> +
>> + serial_out(port, SPRD_IEN, ien);
>> + serial_out(port, SPRD_ICLR, iclr);
>> +}
>> +
>> +/* The Sprd serial does not support this function. */
>> +static void sprd_break_ctl(struct uart_port *port, int break_state)
>> +{
>> + /* nothing to do */
>> +}
>> +
>> +static inline int handle_lsr_errors(struct uart_port *port,
>> + unsigned int *flag,
>> + unsigned int *lsr)
>> +{
>> + int ret = 0;
>> +
>> + /* statistics */
>> + if (*lsr & SPRD_LSR_BI) {
>> + *lsr &= ~(SPRD_LSR_FE | SPRD_LSR_PE);
>> + port->icount.brk++;
>> + ret = uart_handle_break(port);
>> + if (ret)
>> + return ret;
>> + } else if (*lsr & SPRD_LSR_PE)
>> + port->icount.parity++;
>> + else if (*lsr & SPRD_LSR_FE)
>> + port->icount.frame++;
>> + if (*lsr & SPRD_LSR_OE)
>> + port->icount.overrun++;
>> +
>> + /* mask off conditions which should be ignored */
>> + *lsr &= port->read_status_mask;
>> + if (*lsr & SPRD_LSR_BI)
>> + *flag = TTY_BREAK;
>> + else if (*lsr & SPRD_LSR_PE)
>> + *flag = TTY_PARITY;
>> + else if (*lsr & SPRD_LSR_FE)
>> + *flag = TTY_FRAME;
>> +
>> + return ret;
>> +}
>> +
>> +static inline void sprd_rx(int irq, void *dev_id)
>> +{
>> + struct uart_port *port = dev_id;
>> + struct tty_port *tty = &port->state->port;
>> + unsigned int ch, flag, lsr, max_count = SPRD_TIMEOUT;
>> +
>> + while ((serial_in(port, SPRD_STS1) & 0x00ff) && max_count--) {
>> + lsr = serial_in(port, SPRD_LSR);
>> + ch = serial_in(port, SPRD_RXD);
>> + flag = TTY_NORMAL;
>> + port->icount.rx++;
>> +
>> + if (lsr & (SPRD_LSR_BI | SPRD_LSR_PE
>> + | SPRD_LSR_FE | SPRD_LSR_OE))
>> + if (handle_lsr_errors(port, &lsr, &flag))
>> + continue;
>> + if (uart_handle_sysrq_char(port, ch))
>> + continue;
>> +
>> + uart_insert_char(port, lsr, SPRD_LSR_OE, ch, flag);
>> + }
>> +
>> + tty_flip_buffer_push(tty);
>> +}
>> +
>> +static inline void sprd_tx(int irq, void *dev_id)
>> +{
>> + struct uart_port *port = dev_id;
>> + struct circ_buf *xmit = &port->state->xmit;
>> + int count;
>> +
>> + if (port->x_char) {
>> + serial_out(port, SPRD_TXD, port->x_char);
>> + port->icount.tx++;
>> + port->x_char = 0;
>> + return;
>> + }
>> +
>> + if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
>> + sprd_stop_tx(port);
>> + return;
>> + }
>> +
>> + count = THLD_TX_EMPTY;
>> + do {
>> + serial_out(port, SPRD_TXD, xmit->buf[xmit->tail]);
>> + xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
>> + port->icount.tx++;
>> + if (uart_circ_empty(xmit))
>> + break;
>> + } while (--count > 0);
>> +
>> + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
>> + uart_write_wakeup(port);
>> +
>> + if (uart_circ_empty(xmit))
>> + sprd_stop_tx(port);
>> +}
>> +
>> +/* this handles the interrupt from one port */
>> +static irqreturn_t sprd_handle_irq(int irq, void *dev_id)
>> +{
>> + struct uart_port *port = (struct uart_port *)dev_id;
>> + unsigned int ims;
> Why does your isr not have to take port->lock ?
The original consideration is the registers are accessed by isr only.
Interrupt will not be nested because of gic chip driver protection.
So there is not other thread will race on it.
Does this make sense?
>
>> + ims = serial_in(port, SPRD_IMSR);
>> +
>> + if (!ims)
>> + return IRQ_NONE;
>> +
>> + serial_out(port, SPRD_ICLR, ~0);
>> +
>> + if (ims & (SPRD_IMSR_RX_FIFO_FULL |
>> + SPRD_IMSR_BREAK_DETECT | SPRD_IMSR_TIMEOUT))
>> + sprd_rx(irq, port);
>> +
>> + if (ims & SPRD_IMSR_TX_FIFO_EMPTY)
>> + sprd_tx(irq, port);
>> +
>> + return IRQ_HANDLED;
>> +}
>> +
>> +static int sprd_startup(struct uart_port *port)
>> +{
>> + int ret = 0;
>> + unsigned int ien, ctrl1;
>> + unsigned int timeout;
>> + struct sprd_uart_port *sp;
>> +
>> + serial_out(port, SPRD_CTL2, ((THLD_TX_EMPTY << 8) | THLD_RX_FULL));
>> +
>> + /* clear rx fifo */
>> + timeout = SPRD_TIMEOUT;
>> + while (timeout-- && serial_in(port, SPRD_STS1) & 0x00ff)
>> + serial_in(port, SPRD_RXD);
>> +
>> + /* clear tx fifo */
>> + timeout = SPRD_TIMEOUT;
>> + while (timeout-- && serial_in(port, SPRD_STS1) & 0xff00)
>> + cpu_relax();
>> +
>> + /* clear interrupt */
>> + serial_out(port, SPRD_IEN, 0x0);
>> + serial_out(port, SPRD_ICLR, ~0);
>> +
>> + /* allocate irq */
>> + sp = container_of(port, struct sprd_uart_port, port);
>> + snprintf(sp->name, sizeof(sp->name), "sprd_serial%d", port->line);
>> + ret = devm_request_irq(port->dev, port->irq, sprd_handle_irq,
>> + IRQF_SHARED, sp->name, port);
>> + if (ret) {
>> + dev_err(port->dev, "fail to request serial irq %d, ret=%d\n",
>> + port->irq, ret);
>> + return ret;
>> + }
>> + ctrl1 = serial_in(port, SPRD_CTL1);
>> + ctrl1 |= 0x3e00 | THLD_RX_FULL;
>> + serial_out(port, SPRD_CTL1, ctrl1);
>> +
>> + /* enable interrupt */
>> + spin_lock(&port->lock);
>> + ien = serial_in(port, SPRD_IEN);
>> + ien |= SPRD_IEN_RX_FULL | SPRD_IEN_BREAK_DETECT | SPRD_IEN_TIMEOUT;
>> + serial_out(port, SPRD_IEN, ien);
>> + spin_unlock(&port->lock);
>> +
>> + return 0;
>> +}
>> +
>> +static void sprd_shutdown(struct uart_port *port)
>> +{
>> + serial_out(port, SPRD_IEN, 0x0);
>> + serial_out(port, SPRD_ICLR, ~0);
>> + devm_free_irq(port->dev, port->irq, port);
>> +}
>> +
>> +static void sprd_set_termios(struct uart_port *port,
>> + struct ktermios *termios,
>> + struct ktermios *old)
>> +{
>> + unsigned int baud, quot;
>> + unsigned int lcr, fc;
>> +
>> + /* ask the core to calculate the divisor for us */
>> + baud = uart_get_baud_rate(port, termios, old, 1200, 3000000);
>> +
>> + quot = (unsigned int)((port->uartclk + baud / 2) / baud);
>> +
>> + /* set data length */
>> + lcr = serial_in(port, SPRD_LCR);
>> + lcr &= ~SPRD_LCR_DATA_LEN;
>> + switch (termios->c_cflag & CSIZE) {
>> + case CS5:
>> + lcr |= SPRD_LCR_DATA_LEN5;
>> + break;
>> + case CS6:
>> + lcr |= SPRD_LCR_DATA_LEN6;
>> + break;
>> + case CS7:
>> + lcr |= SPRD_LCR_DATA_LEN7;
>> + break;
>> + case CS8:
>> + default:
>> + lcr |= SPRD_LCR_DATA_LEN8;
>> + break;
>> + }
>> +
>> + /* calculate stop bits */
>> + lcr &= ~(SPRD_LCR_STOP_1BIT | SPRD_LCR_STOP_2BIT);
>> + if (termios->c_cflag & CSTOPB)
>> + lcr |= SPRD_LCR_STOP_2BIT;
>> + else
>> + lcr |= SPRD_LCR_STOP_1BIT;
>> +
>> + /* calculate parity */
>> + lcr &= ~SPRD_LCR_PARITY;
>> + termios->c_cflag &= ~CMSPAR; /* no support mark/space */
>> + if (termios->c_cflag & PARENB) {
>> + lcr |= SPRD_LCR_PARITY_EN;
>> + if (termios->c_cflag & PARODD)
>> + lcr |= SPRD_LCR_ODD_PAR;
>> + else
>> + lcr |= SPRD_LCR_EVEN_PAR;
>> + }
>> +
>> + /* change the port state. */
> ^^^^^^^^^^^^^^^^^^^^^^
>
> This means you should be taking the port->lock here... (and disabling
> local interrupts if your isr takes the port->lock)
Yes, I think you are right.
>
>> + /* update the per-port timeout */
>> + uart_update_timeout(port, termios->c_cflag, baud);
>> +
>> + port->read_status_mask = SPRD_LSR_OE;
>> + if (termios->c_iflag & INPCK)
>> + port->read_status_mask |= SPRD_LSR_FE | SPRD_LSR_PE;
>> + if (termios->c_iflag & (BRKINT | PARMRK))
>> + port->read_status_mask |= SPRD_LSR_BI;
>> +
>> + /* characters to ignore */
>> + port->ignore_status_mask = 0;
>> + if (termios->c_iflag & IGNPAR)
>> + port->ignore_status_mask |= SPRD_LSR_PE | SPRD_LSR_FE;
>> + if (termios->c_iflag & IGNBRK) {
>> + port->ignore_status_mask |= SPRD_LSR_BI;
>> + /*
>> + * If we're ignoring parity and break indicators,
>> + * ignore overruns too (for real raw support).
>> + */
>> + if (termios->c_iflag & IGNPAR)
>> + port->ignore_status_mask |= SPRD_LSR_OE;
>> + }
>> +
>> + /* flow control */
>> + fc = serial_in(port, SPRD_CTL1);
>> + fc &= ~(RX_HW_FLOW_CTL_THLD | RX_HW_FLOW_CTL_EN | TX_HW_FLOW_CTL_EN);
>> + if (termios->c_cflag & CRTSCTS) {
>> + fc |= RX_HW_FLOW_CTL_THLD;
>> + fc |= RX_HW_FLOW_CTL_EN;
>> + fc |= TX_HW_FLOW_CTL_EN;
>> + }
>> +
>> + /* clock divider bit0~bit15 */
>> + serial_out(port, SPRD_CLKD0, quot & 0xffff);
>> +
>> + /* clock divider bit16~bit20 */
>> + serial_out(port, SPRD_CLKD1, (quot & 0x1f0000) >> 16);
>> + serial_out(port, SPRD_LCR, lcr);
>> + fc |= 0x3e00 | THLD_RX_FULL;
>> + serial_out(port, SPRD_CTL1, fc);
> and dropping it here.
>
>> + /* Don't rewrite B0 */
>> + if (tty_termios_baud_rate(termios))
>> + tty_termios_encode_baud_rate(termios, baud, baud);
>> +}
>> +
>> +static const char *sprd_type(struct uart_port *port)
>> +{
>> + return "SPX";
>> +}
>> +
>> +static void sprd_release_port(struct uart_port *port)
>> +{
>> + /* nothing to do */
>> +}
>> +
>> +static int sprd_request_port(struct uart_port *port)
>> +{
>> + return 0;
>> +}
>> +
>> +static void sprd_config_port(struct uart_port *port, int flags)
>> +{
>> + if (flags & UART_CONFIG_TYPE)
>> + port->type = PORT_SPRD;
>> +}
>> +
>> +static int sprd_verify_port(struct uart_port *port,
>> + struct serial_struct *ser)
>> +{
>> + if (ser->type != PORT_SPRD)
>> + return -EINVAL;
>> + if (port->irq != ser->irq)
>> + return -EINVAL;
>> + return 0;
>> +}
>> +
>> +static struct uart_ops serial_sprd_ops = {
>> + .tx_empty = sprd_tx_empty,
>> + .get_mctrl = sprd_get_mctrl,
>> + .set_mctrl = sprd_set_mctrl,
>> + .stop_tx = sprd_stop_tx,
>> + .start_tx = sprd_start_tx,
>> + .stop_rx = sprd_stop_rx,
>> + .break_ctl = sprd_break_ctl,
>> + .startup = sprd_startup,
>> + .shutdown = sprd_shutdown,
>> + .set_termios = sprd_set_termios,
>> + .type = sprd_type,
>> + .release_port = sprd_release_port,
>> + .request_port = sprd_request_port,
>> + .config_port = sprd_config_port,
>> + .verify_port = sprd_verify_port,
>> +};
>> +
>> +#ifdef CONFIG_SERIAL_SPRD_CONSOLE
>> +static inline void wait_for_xmitr(struct uart_port *port)
>> +{
>> + unsigned int status, tmout = 10000;
>> +
>> + /* wait up to 10ms for the character(s) to be sent */
>> + do {
>> + status = serial_in(port, SPRD_STS1);
>> + if (--tmout == 0)
>> + break;
>> + udelay(1);
>> + } while (status & 0xff00);
>> +}
>> +
>> +static void sprd_console_putchar(struct uart_port *port, int ch)
>> +{
>> + wait_for_xmitr(port);
>> + serial_out(port, SPRD_TXD, ch);
>> +}
>> +
>> +static void sprd_console_write(struct console *co, const char *s,
>> + unsigned int count)
>> +{
>> + struct uart_port *port = &sprd_port[co->index]->port;
>> + int ien;
>> + int locked = 1;
>> +
>> + if (oops_in_progress)
>> + locked = spin_trylock(&port->lock);
>> + else
>> + spin_lock(&port->lock);
> If you do need to take the port->lock in your isr, then you need to
> disable local irq here.
You mean to use spin_lock_irqsave()?
We do disable irq below....
>
>> + /* save the IEN then disable the interrupts */
>> + ien = serial_in(port, SPRD_IEN);
>> + serial_out(port, SPRD_IEN, 0x0);
Here, we disable port IEN register.
>> +
>> + uart_console_write(port, s, count, sprd_console_putchar);
>> +
>> + /* wait for transmitter to become empty and restore the IEN */
>> + wait_for_xmitr(port);
>> + serial_out(port, SPRD_IEN, ien);
>> + if (locked)
>> + spin_unlock(&port->lock);
>> +}
>> +
>> +static int __init sprd_console_setup(struct console *co, char *options)
>> +{
>> + struct uart_port *port;
>> + int baud = 115200;
>> + int bits = 8;
>> + int parity = 'n';
>> + int flow = 'n';
>> +
>> + if (co->index >= UART_NR_MAX || co->index < 0)
>> + co->index = 0;
>> +
>> + port = &sprd_port[co->index]->port;
>> + if (port == NULL) {
>> + pr_info("serial port %d not yet initialized\n", co->index);
>> + return -ENODEV;
>> + }
>> + if (options)
>> + uart_parse_options(options, &baud, &parity, &bits, &flow);
>> +
>> + return uart_set_options(port, co, baud, parity, bits, flow);
>> +}
>> +
>> +static struct uart_driver sprd_uart_driver;
>> +static struct console sprd_console = {
>> + .name = SPRD_TTY_NAME,
>> + .write = sprd_console_write,
>> + .device = uart_console_device,
>> + .setup = sprd_console_setup,
>> + .flags = CON_PRINTBUFFER,
>> + .index = -1,
>> + .data = &sprd_uart_driver,
>> +};
>> +
>> +#define SPRD_CONSOLE (&sprd_console)
>> +
>> +/* Support for earlycon */
>> +static void sprd_putc(struct uart_port *port, int c)
>> +{
>> + unsigned int timeout = SPRD_TIMEOUT;
>> +
>> + while (timeout-- &&
>> + !(readl(port->membase + SPRD_LSR) & SPRD_LSR_TX_OVER))
>> + cpu_relax();
>> +
>> + writeb(c, port->membase + SPRD_TXD);
>> +}
>> +
>> +static void sprd_early_write(struct console *con, const char *s,
>> + unsigned n)
>> +{
>> + struct earlycon_device *dev = con->data;
>> +
>> + uart_console_write(&dev->port, s, n, sprd_putc);
>> +}
>> +
>> +static int __init sprd_early_console_setup(
>> + struct earlycon_device *device,
>> + const char *opt)
>> +{
>> + if (!device->port.membase)
>> + return -ENODEV;
>> +
>> + device->con->write = sprd_early_write;
>> + return 0;
>> +}
>> +
>> +EARLYCON_DECLARE(sprd_serial, sprd_early_console_setup);
>> +OF_EARLYCON_DECLARE(sprd_serial, "sprd,sc9836-uart",
>> + sprd_early_console_setup);
>> +
>> +#else /* !CONFIG_SERIAL_SPRD_CONSOLE */
>> +#define SPRD_CONSOLE NULL
>> +#endif
>> +
>> +static struct uart_driver sprd_uart_driver = {
>> + .owner = THIS_MODULE,
>> + .driver_name = "sprd_serial",
>> + .dev_name = SPRD_TTY_NAME,
>> + .major = 0,
>> + .minor = 0,
>> + .nr = UART_NR_MAX,
>> + .cons = SPRD_CONSOLE,
>> +};
>> +
>> +static int sprd_probe(struct platform_device *pdev)
>> +{
>> + struct resource *res;
>> + struct device_node *np = pdev->dev.of_node;
>> + struct uart_port *up;
>> + struct clk *clk;
>> + int irq;
>> +
>> + if (np)
>> + pdev->id = of_alias_get_id(np, "serial");
>> +
>> + if (pdev->id < 0 || pdev->id >= UART_NR_MAX) {
>> + dev_err(&pdev->dev, "does not support id %d\n", pdev->id);
>> + return -ENXIO;
>> + }
>> +
>> + sprd_port[pdev->id] = devm_kzalloc(&pdev->dev,
>> + sizeof(*sprd_port[pdev->id]), GFP_KERNEL);
>> + if (!sprd_port[pdev->id])
>> + return -ENOMEM;
>> +
>> + up = &sprd_port[pdev->id]->port;
>> + up->dev = &pdev->dev;
>> + up->line = pdev->id;
>> + up->type = PORT_SPRD;
>> + up->iotype = SERIAL_IO_PORT;
>> + up->uartclk = SPRD_DEF_RATE;
>> + up->fifosize = SPRD_FIFO_SIZE;
>> + up->ops = &serial_sprd_ops;
>> + up->flags = ASYNC_BOOT_AUTOCONF;
>> +
>> + clk = devm_clk_get(&pdev->dev, NULL);
>> + if (!IS_ERR(clk))
>> + up->uartclk = clk_get_rate(clk);
>> +
>> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> + if (!res) {
>> + dev_err(&pdev->dev, "not provide mem resource\n");
>> + return -ENODEV;
>> + }
>> + up->mapbase = res->start;
>> + up->membase = devm_ioremap_resource(&pdev->dev, res);
>> + if (IS_ERR(up->membase))
>> + return PTR_ERR(up->membase);
>> +
>> + irq = platform_get_irq(pdev, 0);
>> + if (irq < 0) {
>> + dev_err(&pdev->dev, "not provide irq resource\n");
>> + return -ENODEV;
>> + }
>> + up->irq = irq;
>> +
>> + platform_set_drvdata(pdev, up);
>> +
>> + return uart_add_one_port(&sprd_uart_driver, up);
>> +}
>> +
>> +static int sprd_remove(struct platform_device *dev)
>> +{
>> + struct uart_port *up = platform_get_drvdata(dev);
>> +
>> + return uart_remove_one_port(&sprd_uart_driver, up);
>> +}
>> +
>> +static int sprd_suspend(struct device *dev)
>> +{
>> + int id = to_platform_device(dev)->id;
>> + struct uart_port *port = &sprd_port[id]->port;
>> + struct reg_backup *reg_bak = &sprd_port[id]->reg_bak;
>> +
>> + reg_bak->ien = serial_in(port, SPRD_IEN);
>> + reg_bak->ctrl0 = serial_in(port, SPRD_LCR);
>> + reg_bak->ctrl1 = serial_in(port, SPRD_CTL1);
>> + reg_bak->ctrl2 = serial_in(port, SPRD_CTL2);
>> + reg_bak->clkd0 = serial_in(port, SPRD_CLKD0);
>> + reg_bak->clkd1 = serial_in(port, SPRD_CLKD1);
> Why are you saving and restoring these register states
> across suspend/resume?
>
> The serial core calls your set_termios() handler upon
> resume (either for the console or if a tty is open)
> so you should be reprogramming the hardware there
> based on the termios settings.
We'll try to address it in V6.
Thanks,
Orson
>
> Regards,
> Peter Hurley
>> +
>> + uart_suspend_port(&sprd_uart_driver, port);
>> +
>> + return 0;
>> +}
>> +
>> +static int sprd_resume(struct device *dev)
>> +{
>> + int id = to_platform_device(dev)->id;
>> + struct uart_port *port = &sprd_port[id]->port;
>> + struct reg_backup *reg_bak = &sprd_port[id]->reg_bak;
>> +
>> + serial_out(port, SPRD_LCR, reg_bak->ctrl0);
>> + serial_out(port, SPRD_CTL1, reg_bak->ctrl1);
>> + serial_out(port, SPRD_CTL2, reg_bak->ctrl2);
>> + serial_out(port, SPRD_CLKD0, reg_bak->clkd0);
>> + serial_out(port, SPRD_CLKD1, reg_bak->clkd1);
>> + serial_out(port, SPRD_IEN, reg_bak->ien);
>> +
>> + uart_resume_port(&sprd_uart_driver, port);
>> +
>> + return 0;
>> +}
>> +
>> +static const struct of_device_id serial_ids[] = {
>> + {.compatible = "sprd,sc9836-uart",},
>> + {}
>> +};
>> +
>> +static SIMPLE_DEV_PM_OPS(sprd_pm_ops, sprd_suspend, sprd_resume);
>> +
>> +static struct platform_driver sprd_platform_driver = {
>> + .probe = sprd_probe,
>> + .remove = sprd_remove,
>> + .driver = {
>> + .name = "sprd_serial",
>> + .of_match_table = of_match_ptr(serial_ids),
>> + .pm = &sprd_pm_ops,
>> + },
>> +};
>> +
>> +static int __init sprd_serial_init(void)
>> +{
>> + int ret = 0;
>> +
>> + ret = uart_register_driver(&sprd_uart_driver);
>> + if (ret)
>> + return ret;
>> +
>> + ret = platform_driver_register(&sprd_platform_driver);
>> + if (ret)
>> + uart_unregister_driver(&sprd_uart_driver);
>> +
>> + return ret;
>> +}
>> +
>> +static void __exit sprd_serial_exit(void)
>> +{
>> + platform_driver_unregister(&sprd_platform_driver);
>> + uart_unregister_driver(&sprd_uart_driver);
>> +}
>> +
>> +module_init(sprd_serial_init);
>> +module_exit(sprd_serial_exit);
>> +
>> +MODULE_LICENSE("GPL v2");
>> +MODULE_DESCRIPTION("Spreadtrum SoC serial driver series");
>> diff --git a/include/uapi/linux/serial_core.h b/include/uapi/linux/serial_core.h
>> index c172180..7e6eb39 100644
>> --- a/include/uapi/linux/serial_core.h
>> +++ b/include/uapi/linux/serial_core.h
>> @@ -248,4 +248,7 @@
>> /* MESON */
>> #define PORT_MESON 109
>>
>> +/* SPRD SERIAL */
>> +#define PORT_SPRD 110
>> +
>> #endif /* _UAPILINUX_SERIAL_CORE_H */
>>
^ permalink raw reply [flat|nested] 81+ messages in thread* Re: [PATCH v5 5/5] tty/serial: Add Spreadtrum sc9836-uart driver support
2015-01-20 12:11 ` Orson Zhai
@ 2015-01-20 13:39 ` Peter Hurley
-1 siblings, 0 replies; 81+ messages in thread
From: Peter Hurley @ 2015-01-20 13:39 UTC (permalink / raw)
To: Orson Zhai, Chunyan Zhang
Cc: gregkh, mark.rutland, arnd, gnomes, broonie, robh+dt, pawel.moll,
ijc+devicetree, galak, will.deacon, catalin.marinas, jslaby,
jason, heiko, florian.vaussard, andrew, rrichter, hytszk,
grant.likely, antonynpavlov, Joel.Schopp, Suravee.Suthikulpanit,
shawn.guo, lea.yan, jorge.ramirez-ortiz, lee.jones, geng.ren,
zhizhou.zhang, lanqing.liu, zhang.lyra, wei.qiao, linux-kernel,
linux-arm-kernel, linux-serial
On 01/20/2015 07:11 AM, Orson Zhai wrote:
> Hi, Peter,
>
> Thank you for reviewing our code!
> Some discussion below.
>
> On 2015年01月16日 23:20, Peter Hurley wrote:
>> On 01/16/2015 05:00 AM, Chunyan Zhang wrote:
>>> Add a full sc9836-uart driver for SC9836 SoC which is based on the
>>> spreadtrum sharkl64 platform.
>>> This driver also support earlycon.
>>> This patch also replaced the spaces between the macros and their
>>> values with the tabs in serial_core.h
>> The locking doesn't look correct. Specific notations below.
>>> +static inline void sprd_tx(int irq, void *dev_id)
>>> +{
>>> + struct uart_port *port = dev_id;
>>> + struct circ_buf *xmit = &port->state->xmit;
>>> + int count;
>>> +
>>> + if (port->x_char) {
>>> + serial_out(port, SPRD_TXD, port->x_char);
>>> + port->icount.tx++;
>>> + port->x_char = 0;
>>> + return;
>>> + }
>>> +
>>> + if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
>>> + sprd_stop_tx(port);
>>> + return;
>>> + }
>>> +
>>> + count = THLD_TX_EMPTY;
>>> + do {
>>> + serial_out(port, SPRD_TXD, xmit->buf[xmit->tail]);
>>> + xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
>>> + port->icount.tx++;
>>> + if (uart_circ_empty(xmit))
>>> + break;
>>> + } while (--count > 0);
>>> +
>>> + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
>>> + uart_write_wakeup(port);
>>> +
>>> + if (uart_circ_empty(xmit))
>>> + sprd_stop_tx(port);
>>> +}
>>> +
>>> +/* this handles the interrupt from one port */
>>> +static irqreturn_t sprd_handle_irq(int irq, void *dev_id)
>>> +{
>>> + struct uart_port *port = (struct uart_port *)dev_id;
>>> + unsigned int ims;
>> Why does your isr not have to take port->lock ?
>
> The original consideration is the registers are accessed by isr only.
> Interrupt will not be nested because of gic chip driver protection.
> So there is not other thread will race on it.
> Does this make sense?
The xmit->buf[] and its indexes could be accessed concurrently.
For example,
CPU 0 | CPU 1
|
sprd_handle_irq | uart_flush_buffer
sprd_tx | spin_lock_irqsave
... |
count = 64 |
do { | xmit->tail = 0
serial_out(xmit->buf[xmit->tail]) |
whoops - what byte did this just output?
I'm sure there's many more possible races, perhaps with worse
outcomes than just 1 bad byte output.
>>
>>> + ims = serial_in(port, SPRD_IMSR);
>>> +
>>> + if (!ims)
>>> + return IRQ_NONE;
>>> +
>>> + serial_out(port, SPRD_ICLR, ~0);
>>> +
>>> + if (ims & (SPRD_IMSR_RX_FIFO_FULL |
>>> + SPRD_IMSR_BREAK_DETECT | SPRD_IMSR_TIMEOUT))
>>> + sprd_rx(irq, port);
>>> +
>>> + if (ims & SPRD_IMSR_TX_FIFO_EMPTY)
>>> + sprd_tx(irq, port);
>>> +
>>> + return IRQ_HANDLED;
>>> +}
[...]
>>> +static void sprd_console_putchar(struct uart_port *port, int ch)
>>> +{
>>> + wait_for_xmitr(port);
>>> + serial_out(port, SPRD_TXD, ch);
>>> +}
>>> +
>>> +static void sprd_console_write(struct console *co, const char *s,
>>> + unsigned int count)
>>> +{
>>> + struct uart_port *port = &sprd_port[co->index]->port;
>>> + int ien;
>>> + int locked = 1;
>>> +
>>> + if (oops_in_progress)
>>> + locked = spin_trylock(&port->lock);
>>> + else
>>> + spin_lock(&port->lock);
>> If you do need to take the port->lock in your isr, then you need to
>> disable local irq here.
>
> You mean to use spin_lock_irqsave()?
>
> We do disable irq below....
But not before an irq could happen with the spin_lock already taken.
printk
...
sprd_console_write
spin_lock
<IRQ>
sprd_handle_irq
spin_lock
** DEADLOCK **
[
Note: some drivers assume that console->write() will always be
called with local interrupts disabled. This is a bad idea and I
have warned those driver authors when this has come up before.
]
Also, since you handle sysrq in your isr the above needs to check
for non-zero port->sysrq and _not_ attempt the spinlock because
the isr will already have it; for example,
<IRQ>
sprd_handle_irq
spin_lock
sprd_rx
...
uart_handle_syrq_char
handle_sysrq
__handle_sysrq
printk
...
sprd_console_write
spin_lock
** DEADLOCK **
Regards,
Peter Hurley
>>
>>> + /* save the IEN then disable the interrupts */
>>> + ien = serial_in(port, SPRD_IEN);
>>> + serial_out(port, SPRD_IEN, 0x0);
>
> Here, we disable port IEN register.
>
>>> +
>>> + uart_console_write(port, s, count, sprd_console_putchar);
>>> +
>>> + /* wait for transmitter to become empty and restore the IEN */
>>> + wait_for_xmitr(port);
>>> + serial_out(port, SPRD_IEN, ien);
>>> + if (locked)
>>> + spin_unlock(&port->lock);
>>> +}
^ permalink raw reply [flat|nested] 81+ messages in thread* [PATCH v5 5/5] tty/serial: Add Spreadtrum sc9836-uart driver support
@ 2015-01-20 13:39 ` Peter Hurley
0 siblings, 0 replies; 81+ messages in thread
From: Peter Hurley @ 2015-01-20 13:39 UTC (permalink / raw)
To: linux-arm-kernel
On 01/20/2015 07:11 AM, Orson Zhai wrote:
> Hi, Peter,
>
> Thank you for reviewing our code!
> Some discussion below.
>
> On 2015?01?16? 23:20, Peter Hurley wrote:
>> On 01/16/2015 05:00 AM, Chunyan Zhang wrote:
>>> Add a full sc9836-uart driver for SC9836 SoC which is based on the
>>> spreadtrum sharkl64 platform.
>>> This driver also support earlycon.
>>> This patch also replaced the spaces between the macros and their
>>> values with the tabs in serial_core.h
>> The locking doesn't look correct. Specific notations below.
>>> +static inline void sprd_tx(int irq, void *dev_id)
>>> +{
>>> + struct uart_port *port = dev_id;
>>> + struct circ_buf *xmit = &port->state->xmit;
>>> + int count;
>>> +
>>> + if (port->x_char) {
>>> + serial_out(port, SPRD_TXD, port->x_char);
>>> + port->icount.tx++;
>>> + port->x_char = 0;
>>> + return;
>>> + }
>>> +
>>> + if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
>>> + sprd_stop_tx(port);
>>> + return;
>>> + }
>>> +
>>> + count = THLD_TX_EMPTY;
>>> + do {
>>> + serial_out(port, SPRD_TXD, xmit->buf[xmit->tail]);
>>> + xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
>>> + port->icount.tx++;
>>> + if (uart_circ_empty(xmit))
>>> + break;
>>> + } while (--count > 0);
>>> +
>>> + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
>>> + uart_write_wakeup(port);
>>> +
>>> + if (uart_circ_empty(xmit))
>>> + sprd_stop_tx(port);
>>> +}
>>> +
>>> +/* this handles the interrupt from one port */
>>> +static irqreturn_t sprd_handle_irq(int irq, void *dev_id)
>>> +{
>>> + struct uart_port *port = (struct uart_port *)dev_id;
>>> + unsigned int ims;
>> Why does your isr not have to take port->lock ?
>
> The original consideration is the registers are accessed by isr only.
> Interrupt will not be nested because of gic chip driver protection.
> So there is not other thread will race on it.
> Does this make sense?
The xmit->buf[] and its indexes could be accessed concurrently.
For example,
CPU 0 | CPU 1
|
sprd_handle_irq | uart_flush_buffer
sprd_tx | spin_lock_irqsave
... |
count = 64 |
do { | xmit->tail = 0
serial_out(xmit->buf[xmit->tail]) |
whoops - what byte did this just output?
I'm sure there's many more possible races, perhaps with worse
outcomes than just 1 bad byte output.
>>
>>> + ims = serial_in(port, SPRD_IMSR);
>>> +
>>> + if (!ims)
>>> + return IRQ_NONE;
>>> +
>>> + serial_out(port, SPRD_ICLR, ~0);
>>> +
>>> + if (ims & (SPRD_IMSR_RX_FIFO_FULL |
>>> + SPRD_IMSR_BREAK_DETECT | SPRD_IMSR_TIMEOUT))
>>> + sprd_rx(irq, port);
>>> +
>>> + if (ims & SPRD_IMSR_TX_FIFO_EMPTY)
>>> + sprd_tx(irq, port);
>>> +
>>> + return IRQ_HANDLED;
>>> +}
[...]
>>> +static void sprd_console_putchar(struct uart_port *port, int ch)
>>> +{
>>> + wait_for_xmitr(port);
>>> + serial_out(port, SPRD_TXD, ch);
>>> +}
>>> +
>>> +static void sprd_console_write(struct console *co, const char *s,
>>> + unsigned int count)
>>> +{
>>> + struct uart_port *port = &sprd_port[co->index]->port;
>>> + int ien;
>>> + int locked = 1;
>>> +
>>> + if (oops_in_progress)
>>> + locked = spin_trylock(&port->lock);
>>> + else
>>> + spin_lock(&port->lock);
>> If you do need to take the port->lock in your isr, then you need to
>> disable local irq here.
>
> You mean to use spin_lock_irqsave()?
>
> We do disable irq below....
But not before an irq could happen with the spin_lock already taken.
printk
...
sprd_console_write
spin_lock
<IRQ>
sprd_handle_irq
spin_lock
** DEADLOCK **
[
Note: some drivers assume that console->write() will always be
called with local interrupts disabled. This is a bad idea and I
have warned those driver authors when this has come up before.
]
Also, since you handle sysrq in your isr the above needs to check
for non-zero port->sysrq and _not_ attempt the spinlock because
the isr will already have it; for example,
<IRQ>
sprd_handle_irq
spin_lock
sprd_rx
...
uart_handle_syrq_char
handle_sysrq
__handle_sysrq
printk
...
sprd_console_write
spin_lock
** DEADLOCK **
Regards,
Peter Hurley
>>
>>> + /* save the IEN then disable the interrupts */
>>> + ien = serial_in(port, SPRD_IEN);
>>> + serial_out(port, SPRD_IEN, 0x0);
>
> Here, we disable port IEN register.
>
>>> +
>>> + uart_console_write(port, s, count, sprd_console_putchar);
>>> +
>>> + /* wait for transmitter to become empty and restore the IEN */
>>> + wait_for_xmitr(port);
>>> + serial_out(port, SPRD_IEN, ien);
>>> + if (locked)
>>> + spin_unlock(&port->lock);
>>> +}
^ permalink raw reply [flat|nested] 81+ messages in thread
* Re: [PATCH v5 5/5] tty/serial: Add Spreadtrum sc9836-uart driver support
@ 2015-01-16 16:41 ` Rob Herring
0 siblings, 0 replies; 81+ messages in thread
From: Rob Herring @ 2015-01-16 16:41 UTC (permalink / raw)
To: Chunyan Zhang
Cc: Greg Kroah-Hartman, Mark Rutland, Arnd Bergmann,
One Thousand Gnomes, Mark Brown, Rob Herring, Pawel Moll,
Ian Campbell, Kumar Gala, Will Deacon, Catalin Marinas,
Jiri Slaby, Jason Cooper, Heiko Stübner, Florian Vaussard,
Andrew Lunn, Robert Richter, Hayato Suzuki, Grant Likely,
Antony Pavlov, Joel Schopp, Suravee Suthikulanit, Shawn Guo,
lea.yan, jorge.ramirez-ortiz, Lee Jones, Orson Zhai, geng.ren,
zhizhou.zhang, lanqing.liu, Lyra Zhang, wei.qiao, devicetree,
linux-api, linux-kernel, linux-arm-kernel, linux-serial
On Fri, Jan 16, 2015 at 4:00 AM, Chunyan Zhang
<chunyan.zhang@spreadtrum.com> wrote:
> Add a full sc9836-uart driver for SC9836 SoC which is based on the
> spreadtrum sharkl64 platform.
> This driver also support earlycon.
> This patch also replaced the spaces between the macros and their
> values with the tabs in serial_core.h
>
> Signed-off-by: Chunyan Zhang <chunyan.zhang@spreadtrum.com>
> Signed-off-by: Orson Zhai <orson.zhai@spreadtrum.com>
> Originally-by: Lanqing Liu <lanqing.liu@spreadtrum.com>
> ---
> drivers/tty/serial/Kconfig | 18 +
> drivers/tty/serial/Makefile | 1 +
> drivers/tty/serial/sprd_serial.c | 772 ++++++++++++++++++++++++++++++++++++++
> include/uapi/linux/serial_core.h | 3 +
> 4 files changed, 794 insertions(+)
> create mode 100644 drivers/tty/serial/sprd_serial.c
>
> diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
> index c79b43c..969d3cd 100644
> --- a/drivers/tty/serial/Kconfig
> +++ b/drivers/tty/serial/Kconfig
> @@ -1577,6 +1577,24 @@ config SERIAL_MEN_Z135
> This driver can also be build as a module. If so, the module will be called
> men_z135_uart.ko
>
> +config SERIAL_SPRD
> + tristate "Support for SPRD serial"
Can the menu text spell out Spreadtrum. What SPRD means is not obvious.
> + depends on ARCH_SPRD
> + select SERIAL_CORE
> + help
> + This enables the driver for the Spreadtrum's serial.
> +
> +config SERIAL_SPRD_CONSOLE
> + bool "SPRD UART console support"
Same here.
> + depends on SERIAL_SPRD=y
> + select SERIAL_CORE_CONSOLE
> + select SERIAL_EARLYCON
> + help
> + Support for early debug console using Spreadtrum's serial. This enables
> + the console before standard serial driver is probed. This is enabled
> + with "earlycon" on the kernel command line. The console is
> + enabled when early_param is processed.
> +
> endmenu
>
> config SERIAL_MCTRL_GPIO
> diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile
> index 9a548ac..4801aca 100644
> --- a/drivers/tty/serial/Makefile
> +++ b/drivers/tty/serial/Makefile
> @@ -93,6 +93,7 @@ obj-$(CONFIG_SERIAL_ARC) += arc_uart.o
> obj-$(CONFIG_SERIAL_RP2) += rp2.o
> obj-$(CONFIG_SERIAL_FSL_LPUART) += fsl_lpuart.o
> obj-$(CONFIG_SERIAL_MEN_Z135) += men_z135_uart.o
> +obj-$(CONFIG_SERIAL_SPRD) += sprd_serial.o
>
> # GPIOLIB helpers for modem control lines
> obj-$(CONFIG_SERIAL_MCTRL_GPIO) += serial_mctrl_gpio.o
> diff --git a/drivers/tty/serial/sprd_serial.c b/drivers/tty/serial/sprd_serial.c
> new file mode 100644
> index 0000000..81839e4
> --- /dev/null
> +++ b/drivers/tty/serial/sprd_serial.c
> @@ -0,0 +1,772 @@
> +/*
> + * Copyright (C) 2012 Spreadtrum Communications Inc.
This is unchanged in 3 years?
> + *
> + * This software is licensed under the terms of the GNU General Public
> + * License version 2, as published by the Free Software Foundation, and
> + * may be copied, distributed, and modified under those terms.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/console.h>
> +#include <linux/delay.h>
> +#include <linux/io.h>
> +#include <linux/ioport.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/serial_core.h>
> +#include <linux/serial.h>
> +#include <linux/slab.h>
> +#include <linux/tty.h>
> +#include <linux/tty_flip.h>
> +
> +/* device name */
> +#define UART_NR_MAX 8
> +#define SPRD_TTY_NAME "ttySPX"
We really want to get away from per SOC serial names and use ttyS for
serial port /dev names. There's issues switching existing drivers
because this creates an ABI, so we can only have new drivers follow
this.
[...]
> +static struct platform_driver sprd_platform_driver = {
> + .probe = sprd_probe,
> + .remove = sprd_remove,
> + .driver = {
> + .name = "sprd_serial",
> + .of_match_table = of_match_ptr(serial_ids),
> + .pm = &sprd_pm_ops,
> + },
> +};
> +
> +static int __init sprd_serial_init(void)
> +{
> + int ret = 0;
> +
> + ret = uart_register_driver(&sprd_uart_driver);
This can be done in probe now. Then you can use module_platform_driver().
Rob
^ permalink raw reply [flat|nested] 81+ messages in thread* [PATCH v5 5/5] tty/serial: Add Spreadtrum sc9836-uart driver support
@ 2015-01-16 16:41 ` Rob Herring
0 siblings, 0 replies; 81+ messages in thread
From: Rob Herring @ 2015-01-16 16:41 UTC (permalink / raw)
To: linux-arm-kernel
On Fri, Jan 16, 2015 at 4:00 AM, Chunyan Zhang
<chunyan.zhang@spreadtrum.com> wrote:
> Add a full sc9836-uart driver for SC9836 SoC which is based on the
> spreadtrum sharkl64 platform.
> This driver also support earlycon.
> This patch also replaced the spaces between the macros and their
> values with the tabs in serial_core.h
>
> Signed-off-by: Chunyan Zhang <chunyan.zhang@spreadtrum.com>
> Signed-off-by: Orson Zhai <orson.zhai@spreadtrum.com>
> Originally-by: Lanqing Liu <lanqing.liu@spreadtrum.com>
> ---
> drivers/tty/serial/Kconfig | 18 +
> drivers/tty/serial/Makefile | 1 +
> drivers/tty/serial/sprd_serial.c | 772 ++++++++++++++++++++++++++++++++++++++
> include/uapi/linux/serial_core.h | 3 +
> 4 files changed, 794 insertions(+)
> create mode 100644 drivers/tty/serial/sprd_serial.c
>
> diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
> index c79b43c..969d3cd 100644
> --- a/drivers/tty/serial/Kconfig
> +++ b/drivers/tty/serial/Kconfig
> @@ -1577,6 +1577,24 @@ config SERIAL_MEN_Z135
> This driver can also be build as a module. If so, the module will be called
> men_z135_uart.ko
>
> +config SERIAL_SPRD
> + tristate "Support for SPRD serial"
Can the menu text spell out Spreadtrum. What SPRD means is not obvious.
> + depends on ARCH_SPRD
> + select SERIAL_CORE
> + help
> + This enables the driver for the Spreadtrum's serial.
> +
> +config SERIAL_SPRD_CONSOLE
> + bool "SPRD UART console support"
Same here.
> + depends on SERIAL_SPRD=y
> + select SERIAL_CORE_CONSOLE
> + select SERIAL_EARLYCON
> + help
> + Support for early debug console using Spreadtrum's serial. This enables
> + the console before standard serial driver is probed. This is enabled
> + with "earlycon" on the kernel command line. The console is
> + enabled when early_param is processed.
> +
> endmenu
>
> config SERIAL_MCTRL_GPIO
> diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile
> index 9a548ac..4801aca 100644
> --- a/drivers/tty/serial/Makefile
> +++ b/drivers/tty/serial/Makefile
> @@ -93,6 +93,7 @@ obj-$(CONFIG_SERIAL_ARC) += arc_uart.o
> obj-$(CONFIG_SERIAL_RP2) += rp2.o
> obj-$(CONFIG_SERIAL_FSL_LPUART) += fsl_lpuart.o
> obj-$(CONFIG_SERIAL_MEN_Z135) += men_z135_uart.o
> +obj-$(CONFIG_SERIAL_SPRD) += sprd_serial.o
>
> # GPIOLIB helpers for modem control lines
> obj-$(CONFIG_SERIAL_MCTRL_GPIO) += serial_mctrl_gpio.o
> diff --git a/drivers/tty/serial/sprd_serial.c b/drivers/tty/serial/sprd_serial.c
> new file mode 100644
> index 0000000..81839e4
> --- /dev/null
> +++ b/drivers/tty/serial/sprd_serial.c
> @@ -0,0 +1,772 @@
> +/*
> + * Copyright (C) 2012 Spreadtrum Communications Inc.
This is unchanged in 3 years?
> + *
> + * This software is licensed under the terms of the GNU General Public
> + * License version 2, as published by the Free Software Foundation, and
> + * may be copied, distributed, and modified under those terms.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/console.h>
> +#include <linux/delay.h>
> +#include <linux/io.h>
> +#include <linux/ioport.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/serial_core.h>
> +#include <linux/serial.h>
> +#include <linux/slab.h>
> +#include <linux/tty.h>
> +#include <linux/tty_flip.h>
> +
> +/* device name */
> +#define UART_NR_MAX 8
> +#define SPRD_TTY_NAME "ttySPX"
We really want to get away from per SOC serial names and use ttyS for
serial port /dev names. There's issues switching existing drivers
because this creates an ABI, so we can only have new drivers follow
this.
[...]
> +static struct platform_driver sprd_platform_driver = {
> + .probe = sprd_probe,
> + .remove = sprd_remove,
> + .driver = {
> + .name = "sprd_serial",
> + .of_match_table = of_match_ptr(serial_ids),
> + .pm = &sprd_pm_ops,
> + },
> +};
> +
> +static int __init sprd_serial_init(void)
> +{
> + int ret = 0;
> +
> + ret = uart_register_driver(&sprd_uart_driver);
This can be done in probe now. Then you can use module_platform_driver().
Rob
^ permalink raw reply [flat|nested] 81+ messages in thread* Re: [PATCH v5 5/5] tty/serial: Add Spreadtrum sc9836-uart driver support
@ 2015-01-16 16:41 ` Rob Herring
0 siblings, 0 replies; 81+ messages in thread
From: Rob Herring @ 2015-01-16 16:41 UTC (permalink / raw)
To: Chunyan Zhang
Cc: Greg Kroah-Hartman, Mark Rutland, Arnd Bergmann,
One Thousand Gnomes, Mark Brown, Rob Herring, Pawel Moll,
Ian Campbell, Kumar Gala, Will Deacon, Catalin Marinas,
Jiri Slaby, Jason Cooper, Heiko Stübner, Florian Vaussard,
Andrew Lunn, Robert Richter, Hayato Suzuki, Grant Likely,
Antony Pavlov, Joel Schopp, Suravee Suthikulanit
On Fri, Jan 16, 2015 at 4:00 AM, Chunyan Zhang
<chunyan.zhang-lxIno14LUO0EEoCn2XhGlw@public.gmane.org> wrote:
> Add a full sc9836-uart driver for SC9836 SoC which is based on the
> spreadtrum sharkl64 platform.
> This driver also support earlycon.
> This patch also replaced the spaces between the macros and their
> values with the tabs in serial_core.h
>
> Signed-off-by: Chunyan Zhang <chunyan.zhang-lxIno14LUO0EEoCn2XhGlw@public.gmane.org>
> Signed-off-by: Orson Zhai <orson.zhai-lxIno14LUO0EEoCn2XhGlw@public.gmane.org>
> Originally-by: Lanqing Liu <lanqing.liu-lxIno14LUO0EEoCn2XhGlw@public.gmane.org>
> ---
> drivers/tty/serial/Kconfig | 18 +
> drivers/tty/serial/Makefile | 1 +
> drivers/tty/serial/sprd_serial.c | 772 ++++++++++++++++++++++++++++++++++++++
> include/uapi/linux/serial_core.h | 3 +
> 4 files changed, 794 insertions(+)
> create mode 100644 drivers/tty/serial/sprd_serial.c
>
> diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
> index c79b43c..969d3cd 100644
> --- a/drivers/tty/serial/Kconfig
> +++ b/drivers/tty/serial/Kconfig
> @@ -1577,6 +1577,24 @@ config SERIAL_MEN_Z135
> This driver can also be build as a module. If so, the module will be called
> men_z135_uart.ko
>
> +config SERIAL_SPRD
> + tristate "Support for SPRD serial"
Can the menu text spell out Spreadtrum. What SPRD means is not obvious.
> + depends on ARCH_SPRD
> + select SERIAL_CORE
> + help
> + This enables the driver for the Spreadtrum's serial.
> +
> +config SERIAL_SPRD_CONSOLE
> + bool "SPRD UART console support"
Same here.
> + depends on SERIAL_SPRD=y
> + select SERIAL_CORE_CONSOLE
> + select SERIAL_EARLYCON
> + help
> + Support for early debug console using Spreadtrum's serial. This enables
> + the console before standard serial driver is probed. This is enabled
> + with "earlycon" on the kernel command line. The console is
> + enabled when early_param is processed.
> +
> endmenu
>
> config SERIAL_MCTRL_GPIO
> diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile
> index 9a548ac..4801aca 100644
> --- a/drivers/tty/serial/Makefile
> +++ b/drivers/tty/serial/Makefile
> @@ -93,6 +93,7 @@ obj-$(CONFIG_SERIAL_ARC) += arc_uart.o
> obj-$(CONFIG_SERIAL_RP2) += rp2.o
> obj-$(CONFIG_SERIAL_FSL_LPUART) += fsl_lpuart.o
> obj-$(CONFIG_SERIAL_MEN_Z135) += men_z135_uart.o
> +obj-$(CONFIG_SERIAL_SPRD) += sprd_serial.o
>
> # GPIOLIB helpers for modem control lines
> obj-$(CONFIG_SERIAL_MCTRL_GPIO) += serial_mctrl_gpio.o
> diff --git a/drivers/tty/serial/sprd_serial.c b/drivers/tty/serial/sprd_serial.c
> new file mode 100644
> index 0000000..81839e4
> --- /dev/null
> +++ b/drivers/tty/serial/sprd_serial.c
> @@ -0,0 +1,772 @@
> +/*
> + * Copyright (C) 2012 Spreadtrum Communications Inc.
This is unchanged in 3 years?
> + *
> + * This software is licensed under the terms of the GNU General Public
> + * License version 2, as published by the Free Software Foundation, and
> + * may be copied, distributed, and modified under those terms.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/console.h>
> +#include <linux/delay.h>
> +#include <linux/io.h>
> +#include <linux/ioport.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/serial_core.h>
> +#include <linux/serial.h>
> +#include <linux/slab.h>
> +#include <linux/tty.h>
> +#include <linux/tty_flip.h>
> +
> +/* device name */
> +#define UART_NR_MAX 8
> +#define SPRD_TTY_NAME "ttySPX"
We really want to get away from per SOC serial names and use ttyS for
serial port /dev names. There's issues switching existing drivers
because this creates an ABI, so we can only have new drivers follow
this.
[...]
> +static struct platform_driver sprd_platform_driver = {
> + .probe = sprd_probe,
> + .remove = sprd_remove,
> + .driver = {
> + .name = "sprd_serial",
> + .of_match_table = of_match_ptr(serial_ids),
> + .pm = &sprd_pm_ops,
> + },
> +};
> +
> +static int __init sprd_serial_init(void)
> +{
> + int ret = 0;
> +
> + ret = uart_register_driver(&sprd_uart_driver);
This can be done in probe now. Then you can use module_platform_driver().
Rob
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^ permalink raw reply [flat|nested] 81+ messages in thread* Re: [PATCH v5 5/5] tty/serial: Add Spreadtrum sc9836-uart driver support
@ 2015-01-19 9:55 ` Lyra Zhang
0 siblings, 0 replies; 81+ messages in thread
From: Lyra Zhang @ 2015-01-19 9:55 UTC (permalink / raw)
To: Rob Herring
Cc: Chunyan Zhang, Greg Kroah-Hartman, Mark Rutland, Arnd Bergmann,
One Thousand Gnomes, Mark Brown, Rob Herring, Pawel Moll,
Ian Campbell, Kumar Gala, Will Deacon, Catalin Marinas,
Jiri Slaby, Jason Cooper, Heiko Stübner, Florian Vaussard,
Andrew Lunn, Robert Richter, Hayato Suzuki, Grant Likely,
Antony Pavlov, Joel Schopp, Suravee Suthikulanit, Shawn Guo,
lea.yan, Jorge Ramirez-Ortiz, Lee Jones, Orson Zhai, geng.ren,
zhizhou.zhang, lanqing.liu, Wei Qiao (乔伟),
devicetree, linux-api, linux-kernel, linux-arm-kernel,
linux-serial
On Sat, Jan 17, 2015 at 12:41 AM, Rob Herring <robherring2@gmail.com> wrote:
> On Fri, Jan 16, 2015 at 4:00 AM, Chunyan Zhang
> <chunyan.zhang@spreadtrum.com> wrote:
>> Add a full sc9836-uart driver for SC9836 SoC which is based on the
>> spreadtrum sharkl64 platform.
>> This driver also support earlycon.
>> This patch also replaced the spaces between the macros and their
>> values with the tabs in serial_core.h
>>
>> Signed-off-by: Chunyan Zhang <chunyan.zhang@spreadtrum.com>
>> Signed-off-by: Orson Zhai <orson.zhai@spreadtrum.com>
>> Originally-by: Lanqing Liu <lanqing.liu@spreadtrum.com>
>> ---
>> drivers/tty/serial/Kconfig | 18 +
>> drivers/tty/serial/Makefile | 1 +
>> drivers/tty/serial/sprd_serial.c | 772 ++++++++++++++++++++++++++++++++++++++
>> include/uapi/linux/serial_core.h | 3 +
>> 4 files changed, 794 insertions(+)
>> create mode 100644 drivers/tty/serial/sprd_serial.c
>>
>> diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
>> index c79b43c..969d3cd 100644
>> --- a/drivers/tty/serial/Kconfig
>> +++ b/drivers/tty/serial/Kconfig
>> @@ -1577,6 +1577,24 @@ config SERIAL_MEN_Z135
>> This driver can also be build as a module. If so, the module will be called
>> men_z135_uart.ko
>>
>> +config SERIAL_SPRD
>> + tristate "Support for SPRD serial"
>
> Can the menu text spell out Spreadtrum. What SPRD means is not obvious.
>
Ok, I'll address it.
>> + depends on ARCH_SPRD
>> + select SERIAL_CORE
>> + help
>> + This enables the driver for the Spreadtrum's serial.
>> +
>> +config SERIAL_SPRD_CONSOLE
>> + bool "SPRD UART console support"
>
> Same here.
>
>> + depends on SERIAL_SPRD=y
>> + select SERIAL_CORE_CONSOLE
>> + select SERIAL_EARLYCON
>> + help
>> + Support for early debug console using Spreadtrum's serial. This enables
>> + the console before standard serial driver is probed. This is enabled
>> + with "earlycon" on the kernel command line. The console is
>> + enabled when early_param is processed.
>> +
>> endmenu
>>
>> config SERIAL_MCTRL_GPIO
>> diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile
>> index 9a548ac..4801aca 100644
>> --- a/drivers/tty/serial/Makefile
>> +++ b/drivers/tty/serial/Makefile
>> @@ -93,6 +93,7 @@ obj-$(CONFIG_SERIAL_ARC) += arc_uart.o
>> obj-$(CONFIG_SERIAL_RP2) += rp2.o
>> obj-$(CONFIG_SERIAL_FSL_LPUART) += fsl_lpuart.o
>> obj-$(CONFIG_SERIAL_MEN_Z135) += men_z135_uart.o
>> +obj-$(CONFIG_SERIAL_SPRD) += sprd_serial.o
>>
>> # GPIOLIB helpers for modem control lines
>> obj-$(CONFIG_SERIAL_MCTRL_GPIO) += serial_mctrl_gpio.o
>> diff --git a/drivers/tty/serial/sprd_serial.c b/drivers/tty/serial/sprd_serial.c
>> new file mode 100644
>> index 0000000..81839e4
>> --- /dev/null
>> +++ b/drivers/tty/serial/sprd_serial.c
>> @@ -0,0 +1,772 @@
>> +/*
>> + * Copyright (C) 2012 Spreadtrum Communications Inc.
>
> This is unchanged in 3 years?
>
ok, I'll change it to 2012-2015.
>> + *
>> + * This software is licensed under the terms of the GNU General Public
>> + * License version 2, as published by the Free Software Foundation, and
>> + * may be copied, distributed, and modified under those terms.
>> + *
>> + * This program is distributed in the hope that it will be useful,
>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
>> + * GNU General Public License for more details.
>> + */
>> +
>> +#include <linux/clk.h>
>> +#include <linux/console.h>
>> +#include <linux/delay.h>
>> +#include <linux/io.h>
>> +#include <linux/ioport.h>
>> +#include <linux/kernel.h>
>> +#include <linux/module.h>
>> +#include <linux/of.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/serial_core.h>
>> +#include <linux/serial.h>
>> +#include <linux/slab.h>
>> +#include <linux/tty.h>
>> +#include <linux/tty_flip.h>
>> +
>> +/* device name */
>> +#define UART_NR_MAX 8
>> +#define SPRD_TTY_NAME "ttySPX"
>
> We really want to get away from per SOC serial names and use ttyS for
> serial port /dev names. There's issues switching existing drivers
> because this creates an ABI, so we can only have new drivers follow
> this.
>
ok. i see. I'll convert it to ttyS in the next version.
> [...]
>
>> +static struct platform_driver sprd_platform_driver = {
>> + .probe = sprd_probe,
>> + .remove = sprd_remove,
>> + .driver = {
>> + .name = "sprd_serial",
>> + .of_match_table = of_match_ptr(serial_ids),
>> + .pm = &sprd_pm_ops,
>> + },
>> +};
>> +
>> +static int __init sprd_serial_init(void)
>> +{
>> + int ret = 0;
>> +
>> + ret = uart_register_driver(&sprd_uart_driver);
>
> This can be done in probe now. Then you can use module_platform_driver().
>
Question:
1. there are 4 uart ports configured in dt for sprd_serial, so probe
will be called 4 times, but uart_register_driver only needs to be
called one time, so can we use uart_driver.state to check if
uart_register_driver has already been called ?
2. if I use module_platform_driver() instead of
module_init(sprd_serial_init) and module_exit(sprd_serial_exit) , I
must move uart_unregister_driver() which is now processed in
sprd_serial_exit() to sprd_remove(), there is a similar problem with
probe(), sprd_remove() will also be called 4 times, and actually it
should be called only one time. How can we deal with this case?
3. for the second question, we can check the platform_device->id, if
it is equal to the index of last port (e.g. 4 for this case), then
uart_unregister_driver() can be called. Does it work correctly? since
for this case, we must keep the order of releasing ports.
Thanks,
Chunyan
> Rob
^ permalink raw reply [flat|nested] 81+ messages in thread* [PATCH v5 5/5] tty/serial: Add Spreadtrum sc9836-uart driver support
@ 2015-01-19 9:55 ` Lyra Zhang
0 siblings, 0 replies; 81+ messages in thread
From: Lyra Zhang @ 2015-01-19 9:55 UTC (permalink / raw)
To: linux-arm-kernel
On Sat, Jan 17, 2015 at 12:41 AM, Rob Herring <robherring2@gmail.com> wrote:
> On Fri, Jan 16, 2015 at 4:00 AM, Chunyan Zhang
> <chunyan.zhang@spreadtrum.com> wrote:
>> Add a full sc9836-uart driver for SC9836 SoC which is based on the
>> spreadtrum sharkl64 platform.
>> This driver also support earlycon.
>> This patch also replaced the spaces between the macros and their
>> values with the tabs in serial_core.h
>>
>> Signed-off-by: Chunyan Zhang <chunyan.zhang@spreadtrum.com>
>> Signed-off-by: Orson Zhai <orson.zhai@spreadtrum.com>
>> Originally-by: Lanqing Liu <lanqing.liu@spreadtrum.com>
>> ---
>> drivers/tty/serial/Kconfig | 18 +
>> drivers/tty/serial/Makefile | 1 +
>> drivers/tty/serial/sprd_serial.c | 772 ++++++++++++++++++++++++++++++++++++++
>> include/uapi/linux/serial_core.h | 3 +
>> 4 files changed, 794 insertions(+)
>> create mode 100644 drivers/tty/serial/sprd_serial.c
>>
>> diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
>> index c79b43c..969d3cd 100644
>> --- a/drivers/tty/serial/Kconfig
>> +++ b/drivers/tty/serial/Kconfig
>> @@ -1577,6 +1577,24 @@ config SERIAL_MEN_Z135
>> This driver can also be build as a module. If so, the module will be called
>> men_z135_uart.ko
>>
>> +config SERIAL_SPRD
>> + tristate "Support for SPRD serial"
>
> Can the menu text spell out Spreadtrum. What SPRD means is not obvious.
>
Ok, I'll address it.
>> + depends on ARCH_SPRD
>> + select SERIAL_CORE
>> + help
>> + This enables the driver for the Spreadtrum's serial.
>> +
>> +config SERIAL_SPRD_CONSOLE
>> + bool "SPRD UART console support"
>
> Same here.
>
>> + depends on SERIAL_SPRD=y
>> + select SERIAL_CORE_CONSOLE
>> + select SERIAL_EARLYCON
>> + help
>> + Support for early debug console using Spreadtrum's serial. This enables
>> + the console before standard serial driver is probed. This is enabled
>> + with "earlycon" on the kernel command line. The console is
>> + enabled when early_param is processed.
>> +
>> endmenu
>>
>> config SERIAL_MCTRL_GPIO
>> diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile
>> index 9a548ac..4801aca 100644
>> --- a/drivers/tty/serial/Makefile
>> +++ b/drivers/tty/serial/Makefile
>> @@ -93,6 +93,7 @@ obj-$(CONFIG_SERIAL_ARC) += arc_uart.o
>> obj-$(CONFIG_SERIAL_RP2) += rp2.o
>> obj-$(CONFIG_SERIAL_FSL_LPUART) += fsl_lpuart.o
>> obj-$(CONFIG_SERIAL_MEN_Z135) += men_z135_uart.o
>> +obj-$(CONFIG_SERIAL_SPRD) += sprd_serial.o
>>
>> # GPIOLIB helpers for modem control lines
>> obj-$(CONFIG_SERIAL_MCTRL_GPIO) += serial_mctrl_gpio.o
>> diff --git a/drivers/tty/serial/sprd_serial.c b/drivers/tty/serial/sprd_serial.c
>> new file mode 100644
>> index 0000000..81839e4
>> --- /dev/null
>> +++ b/drivers/tty/serial/sprd_serial.c
>> @@ -0,0 +1,772 @@
>> +/*
>> + * Copyright (C) 2012 Spreadtrum Communications Inc.
>
> This is unchanged in 3 years?
>
ok, I'll change it to 2012-2015.
>> + *
>> + * This software is licensed under the terms of the GNU General Public
>> + * License version 2, as published by the Free Software Foundation, and
>> + * may be copied, distributed, and modified under those terms.
>> + *
>> + * This program is distributed in the hope that it will be useful,
>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
>> + * GNU General Public License for more details.
>> + */
>> +
>> +#include <linux/clk.h>
>> +#include <linux/console.h>
>> +#include <linux/delay.h>
>> +#include <linux/io.h>
>> +#include <linux/ioport.h>
>> +#include <linux/kernel.h>
>> +#include <linux/module.h>
>> +#include <linux/of.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/serial_core.h>
>> +#include <linux/serial.h>
>> +#include <linux/slab.h>
>> +#include <linux/tty.h>
>> +#include <linux/tty_flip.h>
>> +
>> +/* device name */
>> +#define UART_NR_MAX 8
>> +#define SPRD_TTY_NAME "ttySPX"
>
> We really want to get away from per SOC serial names and use ttyS for
> serial port /dev names. There's issues switching existing drivers
> because this creates an ABI, so we can only have new drivers follow
> this.
>
ok. i see. I'll convert it to ttyS in the next version.
> [...]
>
>> +static struct platform_driver sprd_platform_driver = {
>> + .probe = sprd_probe,
>> + .remove = sprd_remove,
>> + .driver = {
>> + .name = "sprd_serial",
>> + .of_match_table = of_match_ptr(serial_ids),
>> + .pm = &sprd_pm_ops,
>> + },
>> +};
>> +
>> +static int __init sprd_serial_init(void)
>> +{
>> + int ret = 0;
>> +
>> + ret = uart_register_driver(&sprd_uart_driver);
>
> This can be done in probe now. Then you can use module_platform_driver().
>
Question:
1. there are 4 uart ports configured in dt for sprd_serial, so probe
will be called 4 times, but uart_register_driver only needs to be
called one time, so can we use uart_driver.state to check if
uart_register_driver has already been called ?
2. if I use module_platform_driver() instead of
module_init(sprd_serial_init) and module_exit(sprd_serial_exit) , I
must move uart_unregister_driver() which is now processed in
sprd_serial_exit() to sprd_remove(), there is a similar problem with
probe(), sprd_remove() will also be called 4 times, and actually it
should be called only one time. How can we deal with this case?
3. for the second question, we can check the platform_device->id, if
it is equal to the index of last port (e.g. 4 for this case), then
uart_unregister_driver() can be called. Does it work correctly? since
for this case, we must keep the order of releasing ports.
Thanks,
Chunyan
> Rob
^ permalink raw reply [flat|nested] 81+ messages in thread* Re: [PATCH v5 5/5] tty/serial: Add Spreadtrum sc9836-uart driver support
@ 2015-01-19 9:55 ` Lyra Zhang
0 siblings, 0 replies; 81+ messages in thread
From: Lyra Zhang @ 2015-01-19 9:55 UTC (permalink / raw)
To: Rob Herring
Cc: Chunyan Zhang, Greg Kroah-Hartman, Mark Rutland, Arnd Bergmann,
One Thousand Gnomes, Mark Brown, Rob Herring, Pawel Moll,
Ian Campbell, Kumar Gala, Will Deacon, Catalin Marinas,
Jiri Slaby, Jason Cooper, Heiko Stübner, Florian Vaussard,
Andrew Lunn, Robert Richter, Hayato Suzuki, Grant Likely,
Antony Pavlov, Joel Schopp
On Sat, Jan 17, 2015 at 12:41 AM, Rob Herring <robherring2-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
> On Fri, Jan 16, 2015 at 4:00 AM, Chunyan Zhang
> <chunyan.zhang-lxIno14LUO0EEoCn2XhGlw@public.gmane.org> wrote:
>> Add a full sc9836-uart driver for SC9836 SoC which is based on the
>> spreadtrum sharkl64 platform.
>> This driver also support earlycon.
>> This patch also replaced the spaces between the macros and their
>> values with the tabs in serial_core.h
>>
>> Signed-off-by: Chunyan Zhang <chunyan.zhang-lxIno14LUO0EEoCn2XhGlw@public.gmane.org>
>> Signed-off-by: Orson Zhai <orson.zhai-lxIno14LUO0EEoCn2XhGlw@public.gmane.org>
>> Originally-by: Lanqing Liu <lanqing.liu-lxIno14LUO0EEoCn2XhGlw@public.gmane.org>
>> ---
>> drivers/tty/serial/Kconfig | 18 +
>> drivers/tty/serial/Makefile | 1 +
>> drivers/tty/serial/sprd_serial.c | 772 ++++++++++++++++++++++++++++++++++++++
>> include/uapi/linux/serial_core.h | 3 +
>> 4 files changed, 794 insertions(+)
>> create mode 100644 drivers/tty/serial/sprd_serial.c
>>
>> diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
>> index c79b43c..969d3cd 100644
>> --- a/drivers/tty/serial/Kconfig
>> +++ b/drivers/tty/serial/Kconfig
>> @@ -1577,6 +1577,24 @@ config SERIAL_MEN_Z135
>> This driver can also be build as a module. If so, the module will be called
>> men_z135_uart.ko
>>
>> +config SERIAL_SPRD
>> + tristate "Support for SPRD serial"
>
> Can the menu text spell out Spreadtrum. What SPRD means is not obvious.
>
Ok, I'll address it.
>> + depends on ARCH_SPRD
>> + select SERIAL_CORE
>> + help
>> + This enables the driver for the Spreadtrum's serial.
>> +
>> +config SERIAL_SPRD_CONSOLE
>> + bool "SPRD UART console support"
>
> Same here.
>
>> + depends on SERIAL_SPRD=y
>> + select SERIAL_CORE_CONSOLE
>> + select SERIAL_EARLYCON
>> + help
>> + Support for early debug console using Spreadtrum's serial. This enables
>> + the console before standard serial driver is probed. This is enabled
>> + with "earlycon" on the kernel command line. The console is
>> + enabled when early_param is processed.
>> +
>> endmenu
>>
>> config SERIAL_MCTRL_GPIO
>> diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile
>> index 9a548ac..4801aca 100644
>> --- a/drivers/tty/serial/Makefile
>> +++ b/drivers/tty/serial/Makefile
>> @@ -93,6 +93,7 @@ obj-$(CONFIG_SERIAL_ARC) += arc_uart.o
>> obj-$(CONFIG_SERIAL_RP2) += rp2.o
>> obj-$(CONFIG_SERIAL_FSL_LPUART) += fsl_lpuart.o
>> obj-$(CONFIG_SERIAL_MEN_Z135) += men_z135_uart.o
>> +obj-$(CONFIG_SERIAL_SPRD) += sprd_serial.o
>>
>> # GPIOLIB helpers for modem control lines
>> obj-$(CONFIG_SERIAL_MCTRL_GPIO) += serial_mctrl_gpio.o
>> diff --git a/drivers/tty/serial/sprd_serial.c b/drivers/tty/serial/sprd_serial.c
>> new file mode 100644
>> index 0000000..81839e4
>> --- /dev/null
>> +++ b/drivers/tty/serial/sprd_serial.c
>> @@ -0,0 +1,772 @@
>> +/*
>> + * Copyright (C) 2012 Spreadtrum Communications Inc.
>
> This is unchanged in 3 years?
>
ok, I'll change it to 2012-2015.
>> + *
>> + * This software is licensed under the terms of the GNU General Public
>> + * License version 2, as published by the Free Software Foundation, and
>> + * may be copied, distributed, and modified under those terms.
>> + *
>> + * This program is distributed in the hope that it will be useful,
>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
>> + * GNU General Public License for more details.
>> + */
>> +
>> +#include <linux/clk.h>
>> +#include <linux/console.h>
>> +#include <linux/delay.h>
>> +#include <linux/io.h>
>> +#include <linux/ioport.h>
>> +#include <linux/kernel.h>
>> +#include <linux/module.h>
>> +#include <linux/of.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/serial_core.h>
>> +#include <linux/serial.h>
>> +#include <linux/slab.h>
>> +#include <linux/tty.h>
>> +#include <linux/tty_flip.h>
>> +
>> +/* device name */
>> +#define UART_NR_MAX 8
>> +#define SPRD_TTY_NAME "ttySPX"
>
> We really want to get away from per SOC serial names and use ttyS for
> serial port /dev names. There's issues switching existing drivers
> because this creates an ABI, so we can only have new drivers follow
> this.
>
ok. i see. I'll convert it to ttyS in the next version.
> [...]
>
>> +static struct platform_driver sprd_platform_driver = {
>> + .probe = sprd_probe,
>> + .remove = sprd_remove,
>> + .driver = {
>> + .name = "sprd_serial",
>> + .of_match_table = of_match_ptr(serial_ids),
>> + .pm = &sprd_pm_ops,
>> + },
>> +};
>> +
>> +static int __init sprd_serial_init(void)
>> +{
>> + int ret = 0;
>> +
>> + ret = uart_register_driver(&sprd_uart_driver);
>
> This can be done in probe now. Then you can use module_platform_driver().
>
Question:
1. there are 4 uart ports configured in dt for sprd_serial, so probe
will be called 4 times, but uart_register_driver only needs to be
called one time, so can we use uart_driver.state to check if
uart_register_driver has already been called ?
2. if I use module_platform_driver() instead of
module_init(sprd_serial_init) and module_exit(sprd_serial_exit) , I
must move uart_unregister_driver() which is now processed in
sprd_serial_exit() to sprd_remove(), there is a similar problem with
probe(), sprd_remove() will also be called 4 times, and actually it
should be called only one time. How can we deal with this case?
3. for the second question, we can check the platform_device->id, if
it is equal to the index of last port (e.g. 4 for this case), then
uart_unregister_driver() can be called. Does it work correctly? since
for this case, we must keep the order of releasing ports.
Thanks,
Chunyan
> Rob
^ permalink raw reply [flat|nested] 81+ messages in thread* Re: [PATCH v5 5/5] tty/serial: Add Spreadtrum sc9836-uart driver support
2015-01-19 9:55 ` Lyra Zhang
(?)
@ 2015-01-19 14:11 ` Rob Herring
-1 siblings, 0 replies; 81+ messages in thread
From: Rob Herring @ 2015-01-19 14:11 UTC (permalink / raw)
To: Lyra Zhang
Cc: Chunyan Zhang, Greg Kroah-Hartman, Mark Rutland, Arnd Bergmann,
One Thousand Gnomes, Mark Brown, Rob Herring, Pawel Moll,
Ian Campbell, Kumar Gala, Will Deacon, Catalin Marinas,
Jiri Slaby, Jason Cooper, Heiko Stübner, Florian Vaussard,
Andrew Lunn, Robert Richter, Hayato Suzuki, Grant Likely,
Antony Pavlov, Joel Schopp, Suravee Suthikulanit, Shawn Guo,
lea.yan, Jorge Ramirez-Ortiz, Lee Jones, Orson Zhai, geng.ren,
zhizhou.zhang, lanqing.liu, Wei Qiao (乔伟),
devicetree, linux-api, linux-kernel, linux-arm-kernel,
linux-serial
On Mon, Jan 19, 2015 at 3:55 AM, Lyra Zhang <zhang.lyra@gmail.com> wrote:
> On Sat, Jan 17, 2015 at 12:41 AM, Rob Herring <robherring2@gmail.com> wrote:
>> On Fri, Jan 16, 2015 at 4:00 AM, Chunyan Zhang
>> <chunyan.zhang@spreadtrum.com> wrote:
>>> Add a full sc9836-uart driver for SC9836 SoC which is based on the
>>> spreadtrum sharkl64 platform.
>>> This driver also support earlycon.
>>> This patch also replaced the spaces between the macros and their
>>> values with the tabs in serial_core.h
[...]
>>> +static int __init sprd_serial_init(void)
>>> +{
>>> + int ret = 0;
>>> +
>>> + ret = uart_register_driver(&sprd_uart_driver);
>>
>> This can be done in probe now. Then you can use module_platform_driver().
>>
>
> Question:
> 1. there are 4 uart ports configured in dt for sprd_serial, so probe
> will be called 4 times, but uart_register_driver only needs to be
> called one time, so can we use uart_driver.state to check if
> uart_register_driver has already been called ?
Yes.
> 2. if I use module_platform_driver() instead of
> module_init(sprd_serial_init) and module_exit(sprd_serial_exit) , I
> must move uart_unregister_driver() which is now processed in
> sprd_serial_exit() to sprd_remove(), there is a similar problem with
> probe(), sprd_remove() will also be called 4 times, and actually it
> should be called only one time. How can we deal with this case?
Look at pl01x or Samsung UART drivers which have done this conversion.
> 3. for the second question, we can check the platform_device->id, if
> it is equal to the index of last port (e.g. 4 for this case), then
> uart_unregister_driver() can be called. Does it work correctly? since
> for this case, we must keep the order of releasing ports.
The id will not be the line index in the DT case. I don't think you
can guarantee the order either.
It would be better to make uart_{un}register_driver deal with being
called multiple times so drivers don't have to deal with getting this
correct. I'm not sure if that is feasible though.
Rob
^ permalink raw reply [flat|nested] 81+ messages in thread* [PATCH v5 5/5] tty/serial: Add Spreadtrum sc9836-uart driver support
@ 2015-01-19 14:11 ` Rob Herring
0 siblings, 0 replies; 81+ messages in thread
From: Rob Herring @ 2015-01-19 14:11 UTC (permalink / raw)
To: linux-arm-kernel
On Mon, Jan 19, 2015 at 3:55 AM, Lyra Zhang <zhang.lyra@gmail.com> wrote:
> On Sat, Jan 17, 2015 at 12:41 AM, Rob Herring <robherring2@gmail.com> wrote:
>> On Fri, Jan 16, 2015 at 4:00 AM, Chunyan Zhang
>> <chunyan.zhang@spreadtrum.com> wrote:
>>> Add a full sc9836-uart driver for SC9836 SoC which is based on the
>>> spreadtrum sharkl64 platform.
>>> This driver also support earlycon.
>>> This patch also replaced the spaces between the macros and their
>>> values with the tabs in serial_core.h
[...]
>>> +static int __init sprd_serial_init(void)
>>> +{
>>> + int ret = 0;
>>> +
>>> + ret = uart_register_driver(&sprd_uart_driver);
>>
>> This can be done in probe now. Then you can use module_platform_driver().
>>
>
> Question:
> 1. there are 4 uart ports configured in dt for sprd_serial, so probe
> will be called 4 times, but uart_register_driver only needs to be
> called one time, so can we use uart_driver.state to check if
> uart_register_driver has already been called ?
Yes.
> 2. if I use module_platform_driver() instead of
> module_init(sprd_serial_init) and module_exit(sprd_serial_exit) , I
> must move uart_unregister_driver() which is now processed in
> sprd_serial_exit() to sprd_remove(), there is a similar problem with
> probe(), sprd_remove() will also be called 4 times, and actually it
> should be called only one time. How can we deal with this case?
Look at pl01x or Samsung UART drivers which have done this conversion.
> 3. for the second question, we can check the platform_device->id, if
> it is equal to the index of last port (e.g. 4 for this case), then
> uart_unregister_driver() can be called. Does it work correctly? since
> for this case, we must keep the order of releasing ports.
The id will not be the line index in the DT case. I don't think you
can guarantee the order either.
It would be better to make uart_{un}register_driver deal with being
called multiple times so drivers don't have to deal with getting this
correct. I'm not sure if that is feasible though.
Rob
^ permalink raw reply [flat|nested] 81+ messages in thread* Re: [PATCH v5 5/5] tty/serial: Add Spreadtrum sc9836-uart driver support
@ 2015-01-19 14:11 ` Rob Herring
0 siblings, 0 replies; 81+ messages in thread
From: Rob Herring @ 2015-01-19 14:11 UTC (permalink / raw)
To: Lyra Zhang
Cc: Chunyan Zhang, Greg Kroah-Hartman, Mark Rutland, Arnd Bergmann,
One Thousand Gnomes, Mark Brown, Rob Herring, Pawel Moll,
Ian Campbell, Kumar Gala, Will Deacon, Catalin Marinas,
Jiri Slaby, Jason Cooper, Heiko Stübner, Florian Vaussard,
Andrew Lunn, Robert Richter, Hayato Suzuki, Grant Likely,
Antony Pavlov, Joel Schopp
On Mon, Jan 19, 2015 at 3:55 AM, Lyra Zhang <zhang.lyra@gmail.com> wrote:
> On Sat, Jan 17, 2015 at 12:41 AM, Rob Herring <robherring2@gmail.com> wrote:
>> On Fri, Jan 16, 2015 at 4:00 AM, Chunyan Zhang
>> <chunyan.zhang@spreadtrum.com> wrote:
>>> Add a full sc9836-uart driver for SC9836 SoC which is based on the
>>> spreadtrum sharkl64 platform.
>>> This driver also support earlycon.
>>> This patch also replaced the spaces between the macros and their
>>> values with the tabs in serial_core.h
[...]
>>> +static int __init sprd_serial_init(void)
>>> +{
>>> + int ret = 0;
>>> +
>>> + ret = uart_register_driver(&sprd_uart_driver);
>>
>> This can be done in probe now. Then you can use module_platform_driver().
>>
>
> Question:
> 1. there are 4 uart ports configured in dt for sprd_serial, so probe
> will be called 4 times, but uart_register_driver only needs to be
> called one time, so can we use uart_driver.state to check if
> uart_register_driver has already been called ?
Yes.
> 2. if I use module_platform_driver() instead of
> module_init(sprd_serial_init) and module_exit(sprd_serial_exit) , I
> must move uart_unregister_driver() which is now processed in
> sprd_serial_exit() to sprd_remove(), there is a similar problem with
> probe(), sprd_remove() will also be called 4 times, and actually it
> should be called only one time. How can we deal with this case?
Look at pl01x or Samsung UART drivers which have done this conversion.
> 3. for the second question, we can check the platform_device->id, if
> it is equal to the index of last port (e.g. 4 for this case), then
> uart_unregister_driver() can be called. Does it work correctly? since
> for this case, we must keep the order of releasing ports.
The id will not be the line index in the DT case. I don't think you
can guarantee the order either.
It would be better to make uart_{un}register_driver deal with being
called multiple times so drivers don't have to deal with getting this
correct. I'm not sure if that is feasible though.
Rob
^ permalink raw reply [flat|nested] 81+ messages in thread* Re: [PATCH v5 5/5] tty/serial: Add Spreadtrum sc9836-uart driver support
2015-01-19 14:11 ` Rob Herring
(?)
@ 2015-01-20 7:37 ` Lyra Zhang
-1 siblings, 0 replies; 81+ messages in thread
From: Lyra Zhang @ 2015-01-20 7:37 UTC (permalink / raw)
To: Rob Herring
Cc: Chunyan Zhang, Greg Kroah-Hartman, Mark Rutland, Arnd Bergmann,
One Thousand Gnomes, Mark Brown, Rob Herring, Pawel Moll,
Ian Campbell, Kumar Gala, Will Deacon, Catalin Marinas,
Jiri Slaby, Jason Cooper, Heiko Stübner, Florian Vaussard,
Andrew Lunn, Robert Richter, Hayato Suzuki, Grant Likely,
Antony Pavlov, Joel Schopp, Suravee Suthikulanit, Shawn Guo,
lea.yan, Jorge Ramirez-Ortiz, Orson Zhai, geng.ren,
zhizhou.zhang, lanqing.liu, Wei Qiao (乔伟),
devicetree, linux-api, linux-kernel, linux-arm-kernel,
linux-serial, Lee Jones
Hi, Rob
I still have a question to be conform, specific describes below:
On Mon, Jan 19, 2015 at 10:11 PM, Rob Herring <robherring2@gmail.com> wrote:
> On Mon, Jan 19, 2015 at 3:55 AM, Lyra Zhang <zhang.lyra@gmail.com> wrote:
>> On Sat, Jan 17, 2015 at 12:41 AM, Rob Herring <robherring2@gmail.com> wrote:
>>> On Fri, Jan 16, 2015 at 4:00 AM, Chunyan Zhang
>>> <chunyan.zhang@spreadtrum.com> wrote:
>>>> Add a full sc9836-uart driver for SC9836 SoC which is based on the
>>>> spreadtrum sharkl64 platform.
>>>> This driver also support earlycon.
>>>> This patch also replaced the spaces between the macros and their
>>>> values with the tabs in serial_core.h
>
> [...]
>
>>>> +static int __init sprd_serial_init(void)
>>>> +{
>>>> + int ret = 0;
>>>> +
>>>> + ret = uart_register_driver(&sprd_uart_driver);
>>>
>>> This can be done in probe now. Then you can use module_platform_driver().
>>>
>>
>> Question:
>> 1. there are 4 uart ports configured in dt for sprd_serial, so probe
>> will be called 4 times, but uart_register_driver only needs to be
>> called one time, so can we use uart_driver.state to check if
>> uart_register_driver has already been called ?
>
> Yes.
>
>> 2. if I use module_platform_driver() instead of
>> module_init(sprd_serial_init) and module_exit(sprd_serial_exit) , I
>> must move uart_unregister_driver() which is now processed in
>> sprd_serial_exit() to sprd_remove(), there is a similar problem with
>> probe(), sprd_remove() will also be called 4 times, and actually it
>> should be called only one time. How can we deal with this case?
>
> Look at pl01x or Samsung UART drivers which have done this conversion.
Samsung UART does use module_platform_driver, but pl010/pl011 doesn't.
In the Samsung UART driver, uart_unregister_driver is processed in
remove(), like below:
static int s3c24xx_serial_remove(struct platform_device *dev)
{
struct uart_port *port = s3c24xx_dev_to_port(&dev->dev);
if (port) {
s3c24xx_serial_cpufreq_deregister(to_ourport(port));
uart_remove_one_port(&s3c24xx_uart_drv, port);
}
uart_unregister_driver(&s3c24xx_uart_drv);
}
if this serial has more than one ports, uart_unregister_driver() must
be called multiple times when the device need to be removed.
I think there may be a problem because that uart_unregister_driver()
will do kfree(drv->state) every time when it's called.
Thanks,
Chunyan
>
>> 3. for the second question, we can check the platform_device->id, if
>> it is equal to the index of last port (e.g. 4 for this case), then
>> uart_unregister_driver() can be called. Does it work correctly? since
>> for this case, we must keep the order of releasing ports.
>
> The id will not be the line index in the DT case. I don't think you
> can guarantee the order either.
>
> It would be better to make uart_{un}register_driver deal with being
> called multiple times so drivers don't have to deal with getting this
> correct. I'm not sure if that is feasible though.
>
> Rob
^ permalink raw reply [flat|nested] 81+ messages in thread* [PATCH v5 5/5] tty/serial: Add Spreadtrum sc9836-uart driver support
@ 2015-01-20 7:37 ` Lyra Zhang
0 siblings, 0 replies; 81+ messages in thread
From: Lyra Zhang @ 2015-01-20 7:37 UTC (permalink / raw)
To: linux-arm-kernel
Hi, Rob
I still have a question to be conform, specific describes below:
On Mon, Jan 19, 2015 at 10:11 PM, Rob Herring <robherring2@gmail.com> wrote:
> On Mon, Jan 19, 2015 at 3:55 AM, Lyra Zhang <zhang.lyra@gmail.com> wrote:
>> On Sat, Jan 17, 2015 at 12:41 AM, Rob Herring <robherring2@gmail.com> wrote:
>>> On Fri, Jan 16, 2015 at 4:00 AM, Chunyan Zhang
>>> <chunyan.zhang@spreadtrum.com> wrote:
>>>> Add a full sc9836-uart driver for SC9836 SoC which is based on the
>>>> spreadtrum sharkl64 platform.
>>>> This driver also support earlycon.
>>>> This patch also replaced the spaces between the macros and their
>>>> values with the tabs in serial_core.h
>
> [...]
>
>>>> +static int __init sprd_serial_init(void)
>>>> +{
>>>> + int ret = 0;
>>>> +
>>>> + ret = uart_register_driver(&sprd_uart_driver);
>>>
>>> This can be done in probe now. Then you can use module_platform_driver().
>>>
>>
>> Question:
>> 1. there are 4 uart ports configured in dt for sprd_serial, so probe
>> will be called 4 times, but uart_register_driver only needs to be
>> called one time, so can we use uart_driver.state to check if
>> uart_register_driver has already been called ?
>
> Yes.
>
>> 2. if I use module_platform_driver() instead of
>> module_init(sprd_serial_init) and module_exit(sprd_serial_exit) , I
>> must move uart_unregister_driver() which is now processed in
>> sprd_serial_exit() to sprd_remove(), there is a similar problem with
>> probe(), sprd_remove() will also be called 4 times, and actually it
>> should be called only one time. How can we deal with this case?
>
> Look at pl01x or Samsung UART drivers which have done this conversion.
Samsung UART does use module_platform_driver, but pl010/pl011 doesn't.
In the Samsung UART driver, uart_unregister_driver is processed in
remove(), like below:
static int s3c24xx_serial_remove(struct platform_device *dev)
{
struct uart_port *port = s3c24xx_dev_to_port(&dev->dev);
if (port) {
s3c24xx_serial_cpufreq_deregister(to_ourport(port));
uart_remove_one_port(&s3c24xx_uart_drv, port);
}
uart_unregister_driver(&s3c24xx_uart_drv);
}
if this serial has more than one ports, uart_unregister_driver() must
be called multiple times when the device need to be removed.
I think there may be a problem because that uart_unregister_driver()
will do kfree(drv->state) every time when it's called.
Thanks,
Chunyan
>
>> 3. for the second question, we can check the platform_device->id, if
>> it is equal to the index of last port (e.g. 4 for this case), then
>> uart_unregister_driver() can be called. Does it work correctly? since
>> for this case, we must keep the order of releasing ports.
>
> The id will not be the line index in the DT case. I don't think you
> can guarantee the order either.
>
> It would be better to make uart_{un}register_driver deal with being
> called multiple times so drivers don't have to deal with getting this
> correct. I'm not sure if that is feasible though.
>
> Rob
^ permalink raw reply [flat|nested] 81+ messages in thread* Re: [PATCH v5 5/5] tty/serial: Add Spreadtrum sc9836-uart driver support
@ 2015-01-20 7:37 ` Lyra Zhang
0 siblings, 0 replies; 81+ messages in thread
From: Lyra Zhang @ 2015-01-20 7:37 UTC (permalink / raw)
To: Rob Herring
Cc: Chunyan Zhang, Greg Kroah-Hartman, Mark Rutland, Arnd Bergmann,
One Thousand Gnomes, Mark Brown, Rob Herring, Pawel Moll,
Ian Campbell, Kumar Gala, Will Deacon, Catalin Marinas,
Jiri Slaby, Jason Cooper, Heiko Stübner, Florian Vaussard,
Andrew Lunn, Robert Richter, Hayato Suzuki, Grant Likely,
Antony Pavlov, Joel Schopp
Hi, Rob
I still have a question to be conform, specific describes below:
On Mon, Jan 19, 2015 at 10:11 PM, Rob Herring <robherring2@gmail.com> wrote:
> On Mon, Jan 19, 2015 at 3:55 AM, Lyra Zhang <zhang.lyra@gmail.com> wrote:
>> On Sat, Jan 17, 2015 at 12:41 AM, Rob Herring <robherring2@gmail.com> wrote:
>>> On Fri, Jan 16, 2015 at 4:00 AM, Chunyan Zhang
>>> <chunyan.zhang@spreadtrum.com> wrote:
>>>> Add a full sc9836-uart driver for SC9836 SoC which is based on the
>>>> spreadtrum sharkl64 platform.
>>>> This driver also support earlycon.
>>>> This patch also replaced the spaces between the macros and their
>>>> values with the tabs in serial_core.h
>
> [...]
>
>>>> +static int __init sprd_serial_init(void)
>>>> +{
>>>> + int ret = 0;
>>>> +
>>>> + ret = uart_register_driver(&sprd_uart_driver);
>>>
>>> This can be done in probe now. Then you can use module_platform_driver().
>>>
>>
>> Question:
>> 1. there are 4 uart ports configured in dt for sprd_serial, so probe
>> will be called 4 times, but uart_register_driver only needs to be
>> called one time, so can we use uart_driver.state to check if
>> uart_register_driver has already been called ?
>
> Yes.
>
>> 2. if I use module_platform_driver() instead of
>> module_init(sprd_serial_init) and module_exit(sprd_serial_exit) , I
>> must move uart_unregister_driver() which is now processed in
>> sprd_serial_exit() to sprd_remove(), there is a similar problem with
>> probe(), sprd_remove() will also be called 4 times, and actually it
>> should be called only one time. How can we deal with this case?
>
> Look at pl01x or Samsung UART drivers which have done this conversion.
Samsung UART does use module_platform_driver, but pl010/pl011 doesn't.
In the Samsung UART driver, uart_unregister_driver is processed in
remove(), like below:
static int s3c24xx_serial_remove(struct platform_device *dev)
{
struct uart_port *port = s3c24xx_dev_to_port(&dev->dev);
if (port) {
s3c24xx_serial_cpufreq_deregister(to_ourport(port));
uart_remove_one_port(&s3c24xx_uart_drv, port);
}
uart_unregister_driver(&s3c24xx_uart_drv);
}
if this serial has more than one ports, uart_unregister_driver() must
be called multiple times when the device need to be removed.
I think there may be a problem because that uart_unregister_driver()
will do kfree(drv->state) every time when it's called.
Thanks,
Chunyan
>
>> 3. for the second question, we can check the platform_device->id, if
>> it is equal to the index of last port (e.g. 4 for this case), then
>> uart_unregister_driver() can be called. Does it work correctly? since
>> for this case, we must keep the order of releasing ports.
>
> The id will not be the line index in the DT case. I don't think you
> can guarantee the order either.
>
> It would be better to make uart_{un}register_driver deal with being
> called multiple times so drivers don't have to deal with getting this
> correct. I'm not sure if that is feasible though.
>
> Rob
^ permalink raw reply [flat|nested] 81+ messages in thread* Re: [PATCH v5 5/5] tty/serial: Add Spreadtrum sc9836-uart driver support
@ 2015-01-20 8:41 ` Orson Zhai
0 siblings, 0 replies; 81+ messages in thread
From: Orson Zhai @ 2015-01-20 8:41 UTC (permalink / raw)
To: Lyra Zhang
Cc: Rob Herring, Chunyan Zhang, Greg Kroah-Hartman, Mark Rutland,
Arnd Bergmann, One Thousand Gnomes, Mark Brown, Rob Herring,
Pawel Moll, Ian Campbell, Kumar Gala, Will Deacon,
Catalin Marinas, Jiri Slaby, Jason Cooper, Heiko Stübner,
Florian Vaussard, Andrew Lunn, Robert Richter, Hayato Suzuki,
Grant Likely, Antony Pavlov, Joel Schopp, Suravee Suthikulanit,
Shawn Guo, lea.yan, Jorge Ramirez-Ortiz, geng.ren, zhizhou.zhang,
lanqing.liu, Wei Qiao (乔伟),
devicetree, linux-api, linux-kernel, linux-arm-kernel,
linux-serial, Lee Jones
On Tue, Jan 20, 2015 at 3:37 PM, Lyra Zhang <zhang.lyra@gmail.com> wrote:
> Hi, Rob
>
> I still have a question to be conform, specific describes below:
>
> On Mon, Jan 19, 2015 at 10:11 PM, Rob Herring <robherring2@gmail.com> wrote:
>> On Mon, Jan 19, 2015 at 3:55 AM, Lyra Zhang <zhang.lyra@gmail.com> wrote:
>>> On Sat, Jan 17, 2015 at 12:41 AM, Rob Herring <robherring2@gmail.com> wrote:
>>>> On Fri, Jan 16, 2015 at 4:00 AM, Chunyan Zhang
>>>> <chunyan.zhang@spreadtrum.com> wrote:
>>>>> Add a full sc9836-uart driver for SC9836 SoC which is based on the
>>>>> spreadtrum sharkl64 platform.
>>>>> This driver also support earlycon.
>>>>> This patch also replaced the spaces between the macros and their
>>>>> values with the tabs in serial_core.h
>>
>> [...]
>>
>>>>> +static int __init sprd_serial_init(void)
>>>>> +{
>>>>> + int ret = 0;
>>>>> +
>>>>> + ret = uart_register_driver(&sprd_uart_driver);
>>>>
>>>> This can be done in probe now. Then you can use module_platform_driver().
>>>>
>>>
>>> Question:
>>> 1. there are 4 uart ports configured in dt for sprd_serial, so probe
>>> will be called 4 times, but uart_register_driver only needs to be
>>> called one time, so can we use uart_driver.state to check if
>>> uart_register_driver has already been called ?
>>
>> Yes.
>>
>>> 2. if I use module_platform_driver() instead of
>>> module_init(sprd_serial_init) and module_exit(sprd_serial_exit) , I
>>> must move uart_unregister_driver() which is now processed in
>>> sprd_serial_exit() to sprd_remove(), there is a similar problem with
>>> probe(), sprd_remove() will also be called 4 times, and actually it
>>> should be called only one time. How can we deal with this case?
>>
>> Look at pl01x or Samsung UART drivers which have done this conversion.
>
> Samsung UART does use module_platform_driver, but pl010/pl011 doesn't.
> In the Samsung UART driver, uart_unregister_driver is processed in
> remove(), like below:
>
> static int s3c24xx_serial_remove(struct platform_device *dev)
> {
> struct uart_port *port = s3c24xx_dev_to_port(&dev->dev);
>
> if (port) {
> s3c24xx_serial_cpufreq_deregister(to_ourport(port));
> uart_remove_one_port(&s3c24xx_uart_drv, port);
> }
>
> uart_unregister_driver(&s3c24xx_uart_drv);
> }
>
> if this serial has more than one ports, uart_unregister_driver() must
> be called multiple times when the device need to be removed.
> I think there may be a problem because that uart_unregister_driver()
> will do kfree(drv->state) every time when it's called.
I think it is no appropriate to call uart_unregister_driver() at first
port removing.
The drv->state buffer was shared with all uart ports.
If there are some cases that only 1 port is needed to be removed, that
will destroy all others, isn't it?
Regards,
Orson
>
> Thanks,
> Chunyan
>
>>
>>> 3. for the second question, we can check the platform_device->id, if
>>> it is equal to the index of last port (e.g. 4 for this case), then
>>> uart_unregister_driver() can be called. Does it work correctly? since
>>> for this case, we must keep the order of releasing ports.
>>
>> The id will not be the line index in the DT case. I don't think you
>> can guarantee the order either.
>>
>> It would be better to make uart_{un}register_driver deal with being
>> called multiple times so drivers don't have to deal with getting this
>> correct. I'm not sure if that is feasible though.
>>
>> Rob
^ permalink raw reply [flat|nested] 81+ messages in thread* [PATCH v5 5/5] tty/serial: Add Spreadtrum sc9836-uart driver support
@ 2015-01-20 8:41 ` Orson Zhai
0 siblings, 0 replies; 81+ messages in thread
From: Orson Zhai @ 2015-01-20 8:41 UTC (permalink / raw)
To: linux-arm-kernel
On Tue, Jan 20, 2015 at 3:37 PM, Lyra Zhang <zhang.lyra@gmail.com> wrote:
> Hi, Rob
>
> I still have a question to be conform, specific describes below:
>
> On Mon, Jan 19, 2015 at 10:11 PM, Rob Herring <robherring2@gmail.com> wrote:
>> On Mon, Jan 19, 2015 at 3:55 AM, Lyra Zhang <zhang.lyra@gmail.com> wrote:
>>> On Sat, Jan 17, 2015 at 12:41 AM, Rob Herring <robherring2@gmail.com> wrote:
>>>> On Fri, Jan 16, 2015 at 4:00 AM, Chunyan Zhang
>>>> <chunyan.zhang@spreadtrum.com> wrote:
>>>>> Add a full sc9836-uart driver for SC9836 SoC which is based on the
>>>>> spreadtrum sharkl64 platform.
>>>>> This driver also support earlycon.
>>>>> This patch also replaced the spaces between the macros and their
>>>>> values with the tabs in serial_core.h
>>
>> [...]
>>
>>>>> +static int __init sprd_serial_init(void)
>>>>> +{
>>>>> + int ret = 0;
>>>>> +
>>>>> + ret = uart_register_driver(&sprd_uart_driver);
>>>>
>>>> This can be done in probe now. Then you can use module_platform_driver().
>>>>
>>>
>>> Question:
>>> 1. there are 4 uart ports configured in dt for sprd_serial, so probe
>>> will be called 4 times, but uart_register_driver only needs to be
>>> called one time, so can we use uart_driver.state to check if
>>> uart_register_driver has already been called ?
>>
>> Yes.
>>
>>> 2. if I use module_platform_driver() instead of
>>> module_init(sprd_serial_init) and module_exit(sprd_serial_exit) , I
>>> must move uart_unregister_driver() which is now processed in
>>> sprd_serial_exit() to sprd_remove(), there is a similar problem with
>>> probe(), sprd_remove() will also be called 4 times, and actually it
>>> should be called only one time. How can we deal with this case?
>>
>> Look at pl01x or Samsung UART drivers which have done this conversion.
>
> Samsung UART does use module_platform_driver, but pl010/pl011 doesn't.
> In the Samsung UART driver, uart_unregister_driver is processed in
> remove(), like below:
>
> static int s3c24xx_serial_remove(struct platform_device *dev)
> {
> struct uart_port *port = s3c24xx_dev_to_port(&dev->dev);
>
> if (port) {
> s3c24xx_serial_cpufreq_deregister(to_ourport(port));
> uart_remove_one_port(&s3c24xx_uart_drv, port);
> }
>
> uart_unregister_driver(&s3c24xx_uart_drv);
> }
>
> if this serial has more than one ports, uart_unregister_driver() must
> be called multiple times when the device need to be removed.
> I think there may be a problem because that uart_unregister_driver()
> will do kfree(drv->state) every time when it's called.
I think it is no appropriate to call uart_unregister_driver() at first
port removing.
The drv->state buffer was shared with all uart ports.
If there are some cases that only 1 port is needed to be removed, that
will destroy all others, isn't it?
Regards,
Orson
>
> Thanks,
> Chunyan
>
>>
>>> 3. for the second question, we can check the platform_device->id, if
>>> it is equal to the index of last port (e.g. 4 for this case), then
>>> uart_unregister_driver() can be called. Does it work correctly? since
>>> for this case, we must keep the order of releasing ports.
>>
>> The id will not be the line index in the DT case. I don't think you
>> can guarantee the order either.
>>
>> It would be better to make uart_{un}register_driver deal with being
>> called multiple times so drivers don't have to deal with getting this
>> correct. I'm not sure if that is feasible though.
>>
>> Rob
^ permalink raw reply [flat|nested] 81+ messages in thread* Re: [PATCH v5 5/5] tty/serial: Add Spreadtrum sc9836-uart driver support
@ 2015-01-20 8:41 ` Orson Zhai
0 siblings, 0 replies; 81+ messages in thread
From: Orson Zhai @ 2015-01-20 8:41 UTC (permalink / raw)
To: Lyra Zhang
Cc: Rob Herring, Chunyan Zhang, Greg Kroah-Hartman, Mark Rutland,
Arnd Bergmann, One Thousand Gnomes, Mark Brown, Rob Herring,
Pawel Moll, Ian Campbell, Kumar Gala, Will Deacon,
Catalin Marinas, Jiri Slaby, Jason Cooper, Heiko Stübner,
Florian Vaussard, Andrew Lunn, Robert Richter, Hayato Suzuki,
Grant Likely, Antony Pavlov
On Tue, Jan 20, 2015 at 3:37 PM, Lyra Zhang <zhang.lyra-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
> Hi, Rob
>
> I still have a question to be conform, specific describes below:
>
> On Mon, Jan 19, 2015 at 10:11 PM, Rob Herring <robherring2-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
>> On Mon, Jan 19, 2015 at 3:55 AM, Lyra Zhang <zhang.lyra-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
>>> On Sat, Jan 17, 2015 at 12:41 AM, Rob Herring <robherring2-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
>>>> On Fri, Jan 16, 2015 at 4:00 AM, Chunyan Zhang
>>>> <chunyan.zhang-lxIno14LUO0EEoCn2XhGlw@public.gmane.org> wrote:
>>>>> Add a full sc9836-uart driver for SC9836 SoC which is based on the
>>>>> spreadtrum sharkl64 platform.
>>>>> This driver also support earlycon.
>>>>> This patch also replaced the spaces between the macros and their
>>>>> values with the tabs in serial_core.h
>>
>> [...]
>>
>>>>> +static int __init sprd_serial_init(void)
>>>>> +{
>>>>> + int ret = 0;
>>>>> +
>>>>> + ret = uart_register_driver(&sprd_uart_driver);
>>>>
>>>> This can be done in probe now. Then you can use module_platform_driver().
>>>>
>>>
>>> Question:
>>> 1. there are 4 uart ports configured in dt for sprd_serial, so probe
>>> will be called 4 times, but uart_register_driver only needs to be
>>> called one time, so can we use uart_driver.state to check if
>>> uart_register_driver has already been called ?
>>
>> Yes.
>>
>>> 2. if I use module_platform_driver() instead of
>>> module_init(sprd_serial_init) and module_exit(sprd_serial_exit) , I
>>> must move uart_unregister_driver() which is now processed in
>>> sprd_serial_exit() to sprd_remove(), there is a similar problem with
>>> probe(), sprd_remove() will also be called 4 times, and actually it
>>> should be called only one time. How can we deal with this case?
>>
>> Look at pl01x or Samsung UART drivers which have done this conversion.
>
> Samsung UART does use module_platform_driver, but pl010/pl011 doesn't.
> In the Samsung UART driver, uart_unregister_driver is processed in
> remove(), like below:
>
> static int s3c24xx_serial_remove(struct platform_device *dev)
> {
> struct uart_port *port = s3c24xx_dev_to_port(&dev->dev);
>
> if (port) {
> s3c24xx_serial_cpufreq_deregister(to_ourport(port));
> uart_remove_one_port(&s3c24xx_uart_drv, port);
> }
>
> uart_unregister_driver(&s3c24xx_uart_drv);
> }
>
> if this serial has more than one ports, uart_unregister_driver() must
> be called multiple times when the device need to be removed.
> I think there may be a problem because that uart_unregister_driver()
> will do kfree(drv->state) every time when it's called.
I think it is no appropriate to call uart_unregister_driver() at first
port removing.
The drv->state buffer was shared with all uart ports.
If there are some cases that only 1 port is needed to be removed, that
will destroy all others, isn't it?
Regards,
Orson
>
> Thanks,
> Chunyan
>
>>
>>> 3. for the second question, we can check the platform_device->id, if
>>> it is equal to the index of last port (e.g. 4 for this case), then
>>> uart_unregister_driver() can be called. Does it work correctly? since
>>> for this case, we must keep the order of releasing ports.
>>
>> The id will not be the line index in the DT case. I don't think you
>> can guarantee the order either.
>>
>> It would be better to make uart_{un}register_driver deal with being
>> called multiple times so drivers don't have to deal with getting this
>> correct. I'm not sure if that is feasible though.
>>
>> Rob
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^ permalink raw reply [flat|nested] 81+ messages in thread
* Re: [PATCH v5 5/5] tty/serial: Add Spreadtrum sc9836-uart driver support
@ 2015-01-20 20:17 ` Rob Herring
0 siblings, 0 replies; 81+ messages in thread
From: Rob Herring @ 2015-01-20 20:17 UTC (permalink / raw)
To: Lyra Zhang
Cc: Chunyan Zhang, Greg Kroah-Hartman, Mark Rutland, Arnd Bergmann,
One Thousand Gnomes, Mark Brown, Rob Herring, Pawel Moll,
Ian Campbell, Kumar Gala, Will Deacon, Catalin Marinas,
Jiri Slaby, Jason Cooper, Heiko Stübner, Florian Vaussard,
Andrew Lunn, Robert Richter, Hayato Suzuki, Grant Likely,
Antony Pavlov, Joel Schopp, Suravee Suthikulanit, Shawn Guo,
lea.yan, Jorge Ramirez-Ortiz, Orson Zhai, geng.ren,
zhizhou.zhang, lanqing.liu, Wei Qiao (乔伟),
devicetree, linux-api, linux-kernel, linux-arm-kernel,
linux-serial, Lee Jones
On Tue, Jan 20, 2015 at 1:37 AM, Lyra Zhang <zhang.lyra@gmail.com> wrote:
> Hi, Rob
>
> I still have a question to be conform, specific describes below:
>
> On Mon, Jan 19, 2015 at 10:11 PM, Rob Herring <robherring2@gmail.com> wrote:
>> On Mon, Jan 19, 2015 at 3:55 AM, Lyra Zhang <zhang.lyra@gmail.com> wrote:
>>> On Sat, Jan 17, 2015 at 12:41 AM, Rob Herring <robherring2@gmail.com> wrote:
>>>> On Fri, Jan 16, 2015 at 4:00 AM, Chunyan Zhang
>>>> <chunyan.zhang@spreadtrum.com> wrote:
>>>>> Add a full sc9836-uart driver for SC9836 SoC which is based on the
>>>>> spreadtrum sharkl64 platform.
>>>>> This driver also support earlycon.
>>>>> This patch also replaced the spaces between the macros and their
>>>>> values with the tabs in serial_core.h
>>
>> [...]
>>
>>>>> +static int __init sprd_serial_init(void)
>>>>> +{
>>>>> + int ret = 0;
>>>>> +
>>>>> + ret = uart_register_driver(&sprd_uart_driver);
>>>>
>>>> This can be done in probe now. Then you can use module_platform_driver().
>>>>
>>>
>>> Question:
>>> 1. there are 4 uart ports configured in dt for sprd_serial, so probe
>>> will be called 4 times, but uart_register_driver only needs to be
>>> called one time, so can we use uart_driver.state to check if
>>> uart_register_driver has already been called ?
>>
>> Yes.
>>
>>> 2. if I use module_platform_driver() instead of
>>> module_init(sprd_serial_init) and module_exit(sprd_serial_exit) , I
>>> must move uart_unregister_driver() which is now processed in
>>> sprd_serial_exit() to sprd_remove(), there is a similar problem with
>>> probe(), sprd_remove() will also be called 4 times, and actually it
>>> should be called only one time. How can we deal with this case?
>>
>> Look at pl01x or Samsung UART drivers which have done this conversion.
>
> Samsung UART does use module_platform_driver, but pl010/pl011 doesn't.
That is because pl011 is an amba_device rather than a platform_device
and there is not an equivalent macro for this boilerplate (although I
think one has been posted recently).
> In the Samsung UART driver, uart_unregister_driver is processed in
> remove(), like below:
>
> static int s3c24xx_serial_remove(struct platform_device *dev)
> {
> struct uart_port *port = s3c24xx_dev_to_port(&dev->dev);
>
> if (port) {
> s3c24xx_serial_cpufreq_deregister(to_ourport(port));
> uart_remove_one_port(&s3c24xx_uart_drv, port);
> }
>
> uart_unregister_driver(&s3c24xx_uart_drv);
> }
>
> if this serial has more than one ports, uart_unregister_driver() must
> be called multiple times when the device need to be removed.
> I think there may be a problem because that uart_unregister_driver()
> will do kfree(drv->state) every time when it's called.
Yes. Looks like a bug still in the Samsung driver. So follow what the
pl01x driver does. It had the same problem, but there is a follow-up
commit to fix it.
Rob
^ permalink raw reply [flat|nested] 81+ messages in thread* [PATCH v5 5/5] tty/serial: Add Spreadtrum sc9836-uart driver support
@ 2015-01-20 20:17 ` Rob Herring
0 siblings, 0 replies; 81+ messages in thread
From: Rob Herring @ 2015-01-20 20:17 UTC (permalink / raw)
To: linux-arm-kernel
On Tue, Jan 20, 2015 at 1:37 AM, Lyra Zhang <zhang.lyra@gmail.com> wrote:
> Hi, Rob
>
> I still have a question to be conform, specific describes below:
>
> On Mon, Jan 19, 2015 at 10:11 PM, Rob Herring <robherring2@gmail.com> wrote:
>> On Mon, Jan 19, 2015 at 3:55 AM, Lyra Zhang <zhang.lyra@gmail.com> wrote:
>>> On Sat, Jan 17, 2015 at 12:41 AM, Rob Herring <robherring2@gmail.com> wrote:
>>>> On Fri, Jan 16, 2015 at 4:00 AM, Chunyan Zhang
>>>> <chunyan.zhang@spreadtrum.com> wrote:
>>>>> Add a full sc9836-uart driver for SC9836 SoC which is based on the
>>>>> spreadtrum sharkl64 platform.
>>>>> This driver also support earlycon.
>>>>> This patch also replaced the spaces between the macros and their
>>>>> values with the tabs in serial_core.h
>>
>> [...]
>>
>>>>> +static int __init sprd_serial_init(void)
>>>>> +{
>>>>> + int ret = 0;
>>>>> +
>>>>> + ret = uart_register_driver(&sprd_uart_driver);
>>>>
>>>> This can be done in probe now. Then you can use module_platform_driver().
>>>>
>>>
>>> Question:
>>> 1. there are 4 uart ports configured in dt for sprd_serial, so probe
>>> will be called 4 times, but uart_register_driver only needs to be
>>> called one time, so can we use uart_driver.state to check if
>>> uart_register_driver has already been called ?
>>
>> Yes.
>>
>>> 2. if I use module_platform_driver() instead of
>>> module_init(sprd_serial_init) and module_exit(sprd_serial_exit) , I
>>> must move uart_unregister_driver() which is now processed in
>>> sprd_serial_exit() to sprd_remove(), there is a similar problem with
>>> probe(), sprd_remove() will also be called 4 times, and actually it
>>> should be called only one time. How can we deal with this case?
>>
>> Look at pl01x or Samsung UART drivers which have done this conversion.
>
> Samsung UART does use module_platform_driver, but pl010/pl011 doesn't.
That is because pl011 is an amba_device rather than a platform_device
and there is not an equivalent macro for this boilerplate (although I
think one has been posted recently).
> In the Samsung UART driver, uart_unregister_driver is processed in
> remove(), like below:
>
> static int s3c24xx_serial_remove(struct platform_device *dev)
> {
> struct uart_port *port = s3c24xx_dev_to_port(&dev->dev);
>
> if (port) {
> s3c24xx_serial_cpufreq_deregister(to_ourport(port));
> uart_remove_one_port(&s3c24xx_uart_drv, port);
> }
>
> uart_unregister_driver(&s3c24xx_uart_drv);
> }
>
> if this serial has more than one ports, uart_unregister_driver() must
> be called multiple times when the device need to be removed.
> I think there may be a problem because that uart_unregister_driver()
> will do kfree(drv->state) every time when it's called.
Yes. Looks like a bug still in the Samsung driver. So follow what the
pl01x driver does. It had the same problem, but there is a follow-up
commit to fix it.
Rob
^ permalink raw reply [flat|nested] 81+ messages in thread* Re: [PATCH v5 5/5] tty/serial: Add Spreadtrum sc9836-uart driver support
@ 2015-01-20 20:17 ` Rob Herring
0 siblings, 0 replies; 81+ messages in thread
From: Rob Herring @ 2015-01-20 20:17 UTC (permalink / raw)
To: Lyra Zhang
Cc: Chunyan Zhang, Greg Kroah-Hartman, Mark Rutland, Arnd Bergmann,
One Thousand Gnomes, Mark Brown, Rob Herring, Pawel Moll,
Ian Campbell, Kumar Gala, Will Deacon, Catalin Marinas,
Jiri Slaby, Jason Cooper, Heiko Stübner, Florian Vaussard,
Andrew Lunn, Robert Richter, Hayato Suzuki, Grant Likely,
Antony Pavlov, Joel Schopp
On Tue, Jan 20, 2015 at 1:37 AM, Lyra Zhang <zhang.lyra-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
> Hi, Rob
>
> I still have a question to be conform, specific describes below:
>
> On Mon, Jan 19, 2015 at 10:11 PM, Rob Herring <robherring2-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
>> On Mon, Jan 19, 2015 at 3:55 AM, Lyra Zhang <zhang.lyra-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
>>> On Sat, Jan 17, 2015 at 12:41 AM, Rob Herring <robherring2-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
>>>> On Fri, Jan 16, 2015 at 4:00 AM, Chunyan Zhang
>>>> <chunyan.zhang-lxIno14LUO0EEoCn2XhGlw@public.gmane.org> wrote:
>>>>> Add a full sc9836-uart driver for SC9836 SoC which is based on the
>>>>> spreadtrum sharkl64 platform.
>>>>> This driver also support earlycon.
>>>>> This patch also replaced the spaces between the macros and their
>>>>> values with the tabs in serial_core.h
>>
>> [...]
>>
>>>>> +static int __init sprd_serial_init(void)
>>>>> +{
>>>>> + int ret = 0;
>>>>> +
>>>>> + ret = uart_register_driver(&sprd_uart_driver);
>>>>
>>>> This can be done in probe now. Then you can use module_platform_driver().
>>>>
>>>
>>> Question:
>>> 1. there are 4 uart ports configured in dt for sprd_serial, so probe
>>> will be called 4 times, but uart_register_driver only needs to be
>>> called one time, so can we use uart_driver.state to check if
>>> uart_register_driver has already been called ?
>>
>> Yes.
>>
>>> 2. if I use module_platform_driver() instead of
>>> module_init(sprd_serial_init) and module_exit(sprd_serial_exit) , I
>>> must move uart_unregister_driver() which is now processed in
>>> sprd_serial_exit() to sprd_remove(), there is a similar problem with
>>> probe(), sprd_remove() will also be called 4 times, and actually it
>>> should be called only one time. How can we deal with this case?
>>
>> Look at pl01x or Samsung UART drivers which have done this conversion.
>
> Samsung UART does use module_platform_driver, but pl010/pl011 doesn't.
That is because pl011 is an amba_device rather than a platform_device
and there is not an equivalent macro for this boilerplate (although I
think one has been posted recently).
> In the Samsung UART driver, uart_unregister_driver is processed in
> remove(), like below:
>
> static int s3c24xx_serial_remove(struct platform_device *dev)
> {
> struct uart_port *port = s3c24xx_dev_to_port(&dev->dev);
>
> if (port) {
> s3c24xx_serial_cpufreq_deregister(to_ourport(port));
> uart_remove_one_port(&s3c24xx_uart_drv, port);
> }
>
> uart_unregister_driver(&s3c24xx_uart_drv);
> }
>
> if this serial has more than one ports, uart_unregister_driver() must
> be called multiple times when the device need to be removed.
> I think there may be a problem because that uart_unregister_driver()
> will do kfree(drv->state) every time when it's called.
Yes. Looks like a bug still in the Samsung driver. So follow what the
pl01x driver does. It had the same problem, but there is a follow-up
commit to fix it.
Rob
^ permalink raw reply [flat|nested] 81+ messages in thread