From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751818Ab0CWKb4 (ORCPT ); Tue, 23 Mar 2010 06:31:56 -0400 Received: from qw-out-2122.google.com ([74.125.92.24]:40493 "EHLO qw-out-2122.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751567Ab0CWKbx (ORCPT ); Tue, 23 Mar 2010 06:31:53 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=sender:from:to:cc:subject:date:message-id:x-mailer:in-reply-to :references; b=fZ7ggIezygqIuAUSzKyyprtLQp3+bPCBl168q72X3d6cdfjDtb0oGecfa464POcFao zPDrMpTD504tF4XCGv/ovVUTxTE4PHy/Hg1Oj9u259rfW9XRrli5SRJL9n1rXZ5LshYr YEJ6T/Bsv70Y8tvBX5ITYQNpnHl17FIgsHsXs= From: Christian Pellegrin To: feng.tang@intel.com, akpm@linux-foundation.org, greg@kroah.com, david-b@pacbell.net, grant.likely@secretlab.ca, alan@lxorguk.ukuu.org.uk, spi-devel-general@lists.sourceforge.net, linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Christian Pellegrin Subject: [PATCH v1 3/4] max3100: adds console support for MAX3100 Date: Tue, 23 Mar 2010 11:29:30 +0100 Message-Id: <1269340170-6558-1-git-send-email-chripell@fsfe.org> X-Mailer: git-send-email 1.5.6.5 In-Reply-To: <1269340105-6503-1-git-send-email-chripell@fsfe.org> References: <1269340105-6503-1-git-send-email-chripell@fsfe.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch adds console support for the MAX3100 UART (console=ttyMAX0,11500). The SPI subsystem and an suitable SPI master driver have to be compiled in the kernel. Signed-off-by: Christian Pellegrin --- drivers/serial/Kconfig | 7 ++ drivers/serial/max3100.c | 217 +++++++++++++++++++++++++++++++++++++--- include/linux/serial_max3100.h | 4 + 3 files changed, 212 insertions(+), 16 deletions(-) diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig index 9ff47db..acd758c 100644 --- a/drivers/serial/Kconfig +++ b/drivers/serial/Kconfig @@ -547,6 +547,13 @@ config SERIAL_MAX3100 help MAX3100 chip support +config SERIAL_MAX3100_CONSOLE + bool "Support console on MAX3100" + depends on SERIAL_MAX3100=y + select SERIAL_CORE_CONSOLE + help + Console on MAX3100 + config SERIAL_DZ bool "DECstation DZ serial driver" depends on MACH_DECSTATION && 32BIT diff --git a/drivers/serial/max3100.c b/drivers/serial/max3100.c index 0c972c6..ec3e13a 100644 --- a/drivers/serial/max3100.c +++ b/drivers/serial/max3100.c @@ -48,6 +48,7 @@ #include #include #include +#include #include @@ -131,6 +132,22 @@ struct max3100_port { int poll_time; /* and its timer */ struct timer_list timer; + + int console_flags; + /* is this port a console? */ +#define MAX3100_IS_CONSOLE (1 << 0) + /* are we in suspend/resume? */ +#define MAX3100_SUSPENDING (1 << 1) +#ifdef CONFIG_SERIAL_MAX3100_CONSOLE + /* console buffer */ +#define CONSOLE_BUF_SIZE 4096 + char *console_buf; + int console_head, console_tail; + /* delayed console work because we may have to sleep */ + struct work_struct console_work; + /* char tx timeout */ + int console_tout; +#endif }; static struct max3100_port *max3100s[MAX_MAX3100]; /* the chips */ @@ -175,7 +192,9 @@ static void max3100_resume_work(struct work_struct *w) struct max3100_port *s = container_of(w, struct max3100_port, resume_work); - raise_threaded_irq(s->irq); + if (s->irq) + raise_threaded_irq(s->irq); + s->console_flags &= ~MAX3100_SUSPENDING; } static void max3100_timeout(unsigned long data) @@ -552,14 +571,16 @@ static void max3100_shutdown(struct uart_port *port) if (s->irq) free_irq(s->irq, s); - /* set shutdown mode to save power */ - if (s->max3100_hw_suspend) - s->max3100_hw_suspend(1); - else { - u16 tx, rx; + if (!(s->console_flags & MAX3100_IS_CONSOLE)) { + /* set shutdown mode to save power */ + if (s->max3100_hw_suspend) { + s->max3100_hw_suspend(1); + } else { + u16 tx, rx; - tx = MAX3100_WC | MAX3100_SHDN; - max3100_sr(s, tx, &rx); + tx = MAX3100_WC | MAX3100_SHDN; + max3100_sr(s, tx, &rx); + } } } @@ -578,8 +599,6 @@ static int max3100_startup(struct uart_port *port) s->parity = 0; s->rts = 0; - INIT_WORK(&s->resume_work, max3100_resume_work); - if (request_threaded_irq(s->irq, NULL, max3100_ist, IRQF_TRIGGER_FALLING, "max3100", s) < 0) { dev_err(&s->spi->dev, "cannot allocate irq %d\n", s->irq); @@ -699,6 +718,147 @@ static struct uart_ops max3100_ops = { .verify_port = max3100_verify_port, }; +#ifdef CONFIG_SERIAL_MAX3100_CONSOLE + +static void max3100_console_work(struct work_struct *w) +{ + struct max3100_port *s = container_of(w, struct max3100_port, + console_work); + unsigned long start; + u16 tx, rx; + + while (s->console_head != s->console_tail && + (s->console_flags & MAX3100_SUSPENDING) == 0) { + start = jiffies; + do { + tx = MAX3100_RC; + max3100_sr(s, tx, &rx); + } while ((rx & MAX3100_T) == 0 && + !time_after(jiffies, start + s->console_tout)); + tx = s->console_buf[s->console_tail]; + max3100_calc_parity(s, &tx); + tx |= MAX3100_WD | MAX3100_RTS; + max3100_sr(s, tx, &rx); + s->console_tail = (s->console_tail + 1) % CONSOLE_BUF_SIZE; + } +} + +static void max3100_console_putchar(struct uart_port *port, int ch) +{ + struct max3100_port *s = to_max3100_port(port); + int next = (s->console_head + 1) % CONSOLE_BUF_SIZE; + + if (next != s->console_tail) { + s->console_buf[next] = ch; + s->console_head = next; + } +} + +static void max3100_console_write(struct console *co, + const char *str, unsigned int count) +{ + struct max3100_port *s = max3100s[co->index];; + + uart_console_write(&s->port, str, count, max3100_console_putchar); + schedule_work(&s->console_work); +} + +static int max3100_console_setup(struct console *co, char *options) +{ + struct max3100_port *s; + int baud = 115200; + int bits = 8; + int parity = 'n'; + int flow = 'n'; + int ret; + u16 tx, rx; + + if (co->index == -1 || co->index >= MAX_MAX3100) + co->index = 0; + s = max3100s[co->index]; + if (!s) + return -ENOENT; + + s->console_buf = kmalloc(CONSOLE_BUF_SIZE, GFP_KERNEL); + if (!s->console_buf) + return -ENOMEM; + INIT_WORK(&s->console_work, max3100_console_work); + s->console_flags |= MAX3100_IS_CONSOLE; + + if (options) + uart_parse_options(options, &baud, &parity, &bits, &flow); + ret = uart_set_options(&s->port, co, baud, parity, bits, flow); + + tx = 0; + switch (baud) { + case 300: + tx = 15; + break; + case 600: + tx = 14 + s->crystal; + break; + case 1200: + tx = 13 + s->crystal; + break; + case 2400: + tx = 12 + s->crystal; + break; + case 4800: + tx = 11 + s->crystal; + break; + case 9600: + tx = 10 + s->crystal; + break; + case 19200: + tx = 9 + s->crystal; + break; + case 38400: + tx = 8 + s->crystal; + break; + case 57600: + tx = 1 + s->crystal; + break; + case 115200: + tx = 0 + s->crystal; + break; + case 230400: + tx = 0; + break; + } + if (bits == 7) { + tx |= MAX3100_L; + s->parity |= MAX3100_7BIT; + } + if (parity == 'o' || parity == 'e') { + tx |= MAX3100_PE; + s->parity |= MAX3100_PARITY_ON; + } + if (parity == 'o') + s->parity |= MAX3100_PARITY_ODD; + s->console_tout = 1 + (20 * HZ) / baud; /* jiffies to send 20 bits */ + + tx |= MAX3100_WC; + max3100_sr(s, tx, &rx); + + /* wait for oscilator to stabilize. Data sheet says 25ms, + * apply "multiply by two" engineer's rule */ + msleep(50); + return ret; +} + +static struct uart_driver max3100_uart_driver; +static struct console max3100_console = { + .name = "ttyMAX", + .write = max3100_console_write, + .device = uart_console_device, + .setup = max3100_console_setup, + .flags = CON_PRINTBUFFER, + .index = -1, + .data = &max3100_uart_driver, +}; +static int max3100_console_registered; +#endif + static struct uart_driver max3100_uart_driver = { .owner = THIS_MODULE, .driver_name = "ttyMAX", @@ -706,6 +866,9 @@ static struct uart_driver max3100_uart_driver = { .major = MAX3100_MAJOR, .minor = MAX3100_MINOR, .nr = MAX_MAX3100, +#ifdef CONFIG_SERIAL_MAX3100_CONSOLE + .cons = &max3100_console, +#endif }; static int uart_driver_registered; @@ -768,18 +931,27 @@ static int __devinit max3100_probe(struct spi_device *spi) max3100s[i]->port.line = i; max3100s[i]->port.type = PORT_MAX3100; max3100s[i]->port.dev = &spi->dev; + INIT_WORK(&max3100s[i]->resume_work, max3100_resume_work); retval = uart_add_one_port(&max3100_uart_driver, &max3100s[i]->port); if (retval < 0) dev_warn(&spi->dev, "uart_add_one_port failed for line %d with error %d\n", i, retval); - /* set shutdown mode to save power. Will be woken-up on open */ - if (max3100s[i]->max3100_hw_suspend) - max3100s[i]->max3100_hw_suspend(1); - else { - tx = MAX3100_WC | MAX3100_SHDN; - max3100_sr(max3100s[i], tx, &rx); +#ifdef CONFIG_SERIAL_MAX3100_CONSOLE + if (pdata->console && !max3100_console_registered) { + register_console(&max3100_console); + max3100_console_registered = 1; + } +#endif + if (!(max3100s[i]->console_flags & MAX3100_IS_CONSOLE)) { + /* set shutdown mode to save power. Will be woken-up on open */ + if (max3100s[i]->max3100_hw_suspend) { + max3100s[i]->max3100_hw_suspend(1); + } else { + tx = MAX3100_WC | MAX3100_SHDN; + max3100_sr(max3100s[i], tx, &rx); + } } mutex_unlock(&max3100s_lock); return 0; @@ -792,12 +964,24 @@ static int __devexit max3100_remove(struct spi_device *spi) mutex_lock(&max3100s_lock); +#ifdef CONFIG_SERIAL_MAX3100_CONSOLE + if (max3100_console_registered) { + unregister_console(&max3100_console); + max3100_console_registered = 0; + } +#endif /* find out the index for the chip we are removing */ for (i = 0; i < MAX_MAX3100; i++) if (max3100s[i] == s) break; dev_dbg(&spi->dev, "%s: removing port %d\n", __func__, i); +#ifdef CONFIG_SERIAL_MAX3100_CONSOLE + if (s->console_buf) { + flush_work(&s->console_work); + kfree(s->console_buf); + } +#endif uart_remove_one_port(&max3100_uart_driver, &max3100s[i]->port); kfree(max3100s[i]); max3100s[i] = NULL; @@ -823,6 +1007,7 @@ static int max3100_suspend(struct spi_device *spi, pm_message_t state) dev_dbg(&s->spi->dev, "%s\n", __func__); + s->console_flags |= MAX3100_SUSPENDING; disable_irq(s->irq); if (s->max3100_hw_suspend) diff --git a/include/linux/serial_max3100.h b/include/linux/serial_max3100.h index 4976bef..71fb862 100644 --- a/include/linux/serial_max3100.h +++ b/include/linux/serial_max3100.h @@ -21,6 +21,9 @@ * called on suspend and resume to activate it. * @poll_time: poll time for CTS signal in ms, 0 disables (so no hw * flow ctrl is possible but you have less CPU usage) + * @console: 1 if this MAX3100 is the last one on the system + * (in the order of spi_board_info enumeration) that + * can act as a console. * * You should use this structure in your machine description to specify * how the MAX3100 is connected. Example: @@ -47,6 +50,7 @@ struct plat_max3100 { int crystal; void (*max3100_hw_suspend) (int suspend); int poll_time; + int console; }; #endif -- 1.5.6.5