* [PATCH 1/3 v3]spi: controller driver for Designware SPI core
@ 2009-10-12 6:19 Feng Tang
2009-10-12 22:23 ` Andrew Morton
0 siblings, 1 reply; 2+ messages in thread
From: Feng Tang @ 2009-10-12 6:19 UTC (permalink / raw)
To: David Brownell, Andrew Morton, spi-devel-list
>From 2945f4eab344742d878ea10a774285fe770e6b10 Mon Sep 17 00:00:00 2001
From: Feng Tang <feng.tang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Date: Sat, 10 Oct 2009 14:55:48 +0800
Subject: [PATCH 1/3] spi: controller driver for Designware SPI core
Driver for the Designware SPI core, it supports multipul interfaces
like PCI/APB etc. User can use "dw_apb_ssi_db.pdf" from Synopsys as
HW datasheet.
Signed-off-by: Feng Tang <feng.tang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
---
drivers/spi/Kconfig | 6 +
drivers/spi/Makefile | 1 +
drivers/spi/dw_spi.c | 941 ++++++++++++++++++++++++++++++++++++++++++++
include/linux/spi/dw_spi.h | 212 ++++++++++
4 files changed, 1160 insertions(+), 0 deletions(-)
create mode 100644 drivers/spi/dw_spi.c
create mode 100644 include/linux/spi/dw_spi.h
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 4b6f7cb..6eb9621 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -244,6 +244,12 @@ config SPI_XILINX
See the "OPB Serial Peripheral Interface (SPI) (v1.00e)"
Product Specification document (DS464) for hardware details.
+config SPI_DESIGNWARE
+ bool "DesignWare SPI controller core support"
+ depends on SPI_MASTER
+ help
+ general driver for SPI controller core from DesignWare
+
#
# Add new SPI master controllers in alphabetical order above this line
#
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 21a1182..5cc4e19 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -33,6 +33,7 @@ obj-$(CONFIG_SPI_TXX9) += spi_txx9.o
obj-$(CONFIG_SPI_XILINX) += xilinx_spi.o
obj-$(CONFIG_SPI_SH_SCI) += spi_sh_sci.o
obj-$(CONFIG_SPI_STMP3XXX) += spi_stmp.o
+obj-$(CONFIG_SPI_DESIGNWARE) += dw_spi.o
# ... add above this line ...
# SPI protocol drivers (device/link on bus)
diff --git a/drivers/spi/dw_spi.c b/drivers/spi/dw_spi.c
new file mode 100644
index 0000000..3fd90a6
--- /dev/null
+++ b/drivers/spi/dw_spi.c
@@ -0,0 +1,941 @@
+/*
+ * dw_spi.c - Designware SPI core controller driver (refer pxa2xx_spi.c)
+ *
+ * Copyright (c) 2009, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <linux/dma-mapping.h>
+#include <linux/interrupt.h>
+#include <linux/highmem.h>
+#include <linux/delay.h>
+
+#include <linux/spi/dw_spi.h>
+#include <linux/spi/spi.h>
+
+#ifdef CONFIG_DEBUG_FS
+#include <linux/debugfs.h>
+#endif
+
+#define START_STATE ((void *)0)
+#define RUNNING_STATE ((void *)1)
+#define DONE_STATE ((void *)2)
+#define ERROR_STATE ((void *)-1)
+
+#define QUEUE_RUNNING 0
+#define QUEUE_STOPPED 1
+
+#define MRST_SPI_DEASSERT 0
+#define MRST_SPI_ASSERT 1
+
+/* Slave spi_dev related */
+struct chip_data {
+ u16 cr0;
+ u8 cs; /* chip select pin */
+ u8 n_bytes; /* current is a 1/2/4 byte op */
+ u8 tmode; /* TR/TO/RO/EEPROM */
+ u8 type; /* SPI/SSP/MicroWire */
+
+ u8 poll_mode; /* 1 means use poll mode */
+
+ u32 dma_width;
+ u32 rx_threshold;
+ u32 tx_threshold;
+ u8 enable_dma;
+ u8 bits_per_word;
+ u16 clk_div; /* baud rate divider */
+ u32 speed_hz; /* baud rate */
+ int (*write)(struct dw_spi *dws);
+ int (*read)(struct dw_spi *dws);
+ void (*cs_control)(u32 command);
+};
+
+#ifdef CONFIG_DEBUG_FS
+static int spi_show_regs_open(struct inode *inode, struct file *file)
+{
+ file->private_data = inode->i_private;
+ return 0;
+}
+
+#define SPI_REGS_BUFSIZE 1024
+static ssize_t spi_show_regs(struct file *file, char __user *user_buf,
+ size_t count, loff_t *ppos)
+{
+ struct dw_spi *dws;
+ char *buf;
+ u32 len = 0;
+ ssize_t ret;
+
+ dws = file->private_data;
+
+ buf = kzalloc(SPI_REGS_BUFSIZE, GFP_KERNEL);
+ if (!buf)
+ return 0;
+
+ len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+ "MRST SPI0 registers:\n");
+ len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+ "=================================\n");
+ len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+ "CTRL0: \t\t0x%08x\n", dw_readl(dws, ctrl0));
+ len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+ "CTRL1: \t\t0x%08x\n", dw_readl(dws, ctrl1));
+ len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+ "SSIENR: \t0x%08x\n", dw_readl(dws, ssienr));
+ len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+ "SER: \t\t0x%08x\n", dw_readl(dws, ser));
+ len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+ "BAUDR: \t\t0x%08x\n", dw_readl(dws, baudr));
+ len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+ "TXFTLR: \t0x%08x\n", dw_readl(dws, txfltr));
+ len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+ "RXFTLR: \t0x%08x\n", dw_readl(dws, rxfltr));
+ len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+ "TXFLR: \t\t0x%08x\n", dw_readl(dws, txflr));
+ len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+ "RXFLR: \t\t0x%08x\n", dw_readl(dws, rxflr));
+ len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+ "SR: \t\t0x%08x\n", dw_readl(dws, sr));
+ len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+ "IMR: \t\t0x%08x\n", dw_readl(dws, imr));
+ len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+ "ISR: \t\t0x%08x\n", dw_readl(dws, isr));
+ len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+ "DMACR: \t\t0x%08x\n", dw_readl(dws, dmacr));
+ len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+ "DMATDLR: \t0x%08x\n", dw_readl(dws, dmatdlr));
+ len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+ "DMARDLR: \t0x%08x\n", dw_readl(dws, dmardlr));
+ len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
+ "=================================\n");
+
+ ret = simple_read_from_buffer(user_buf, count, ppos, buf, len);
+ kfree(buf);
+ return ret;
+}
+
+static const struct file_operations mrst_spi_regs_ops = {
+ .owner = THIS_MODULE,
+ .open = spi_show_regs_open,
+ .read = spi_show_regs,
+};
+
+static int mrst_spi_debugfs_init(struct dw_spi *dws)
+{
+ dws->debugfs = debugfs_create_dir("mrst_spi", NULL);
+ if (!dws->debugfs)
+ return -ENOMEM;
+
+ debugfs_create_file("registers", S_IFREG | S_IRUGO,
+ dws->debugfs, (void *)dws, &mrst_spi_regs_ops);
+ return 0;
+}
+
+static void mrst_spi_debugfs_remove(struct dw_spi *dws)
+{
+ if (dws->debugfs)
+ debugfs_remove_recursive(dws->debugfs);
+}
+
+#else
+static inline int mrst_spi_debugfs_init(struct dw_spi *dws)
+{
+}
+
+static inline void mrst_spi_debugfs_remove(struct dw_spi *dws)
+{
+}
+#endif /* CONFIG_DEBUG_FS */
+
+static void wait_till_not_busy(struct dw_spi *dws)
+{
+ unsigned long end = jiffies + usecs_to_jiffies(1000);
+
+ while (time_before(jiffies, end)) {
+ if (!(dw_readw(dws, sr) & SR_BUSY))
+ return;
+ }
+ dev_err(&dws->master->dev,
+ "DW SPI: Stutus keeps busy for 1000us after a read/write!\n");
+}
+
+static void flush(struct dw_spi *dws)
+{
+ while (dw_readw(dws, sr) & SR_RF_NOT_EMPT)
+ dw_readw(dws, dr);
+
+ wait_till_not_busy(dws);
+}
+
+static void null_cs_control(u32 command)
+{
+}
+
+static int null_writer(struct dw_spi *dws)
+{
+ u8 n_bytes = dws->n_bytes;
+
+ if (!(dw_readw(dws, sr) & SR_TF_NOT_FULL)
+ || (dws->tx == dws->tx_end))
+ return 0;
+ dw_writew(dws, dr, 0);
+ dws->tx += n_bytes;
+
+ wait_till_not_busy(dws);
+ return 1;
+}
+
+static int null_reader(struct dw_spi *dws)
+{
+ u8 n_bytes = dws->n_bytes;
+
+ while ((dw_readw(dws, sr) & SR_RF_NOT_EMPT)
+ && (dws->rx < dws->rx_end)) {
+ dw_readw(dws, dr);
+ dws->rx += n_bytes;
+ }
+ wait_till_not_busy(dws);
+ return dws->rx == dws->rx_end;
+}
+
+static int u8_writer(struct dw_spi *dws)
+{
+ if (!(dw_readw(dws, sr) & SR_TF_NOT_FULL)
+ || (dws->tx == dws->tx_end))
+ return 0;
+
+ dw_writew(dws, dr, *(u8 *)(dws->tx));
+ ++dws->tx;
+
+ wait_till_not_busy(dws);
+ return 1;
+}
+
+static int u8_reader(struct dw_spi *dws)
+{
+ while ((dw_readw(dws, sr) & SR_RF_NOT_EMPT)
+ && (dws->rx < dws->rx_end)) {
+ *(u8 *)(dws->rx) = dw_readw(dws, dr);
+ ++dws->rx;
+ }
+
+ wait_till_not_busy(dws);
+ return dws->rx == dws->rx_end;
+}
+
+static int u16_writer(struct dw_spi *dws)
+{
+ if (!(dw_readw(dws, sr) & SR_TF_NOT_FULL)
+ || (dws->tx == dws->tx_end))
+ return 0;
+
+ dw_writew(dws, dr, *(u16 *)(dws->tx));
+ dws->tx += 2;
+
+ wait_till_not_busy(dws);
+ return 1;
+}
+
+static int u16_reader(struct dw_spi *dws)
+{
+ u16 temp;
+
+ while ((dw_readw(dws, sr) & SR_RF_NOT_EMPT)
+ && (dws->rx < dws->rx_end)) {
+ temp = dw_readw(dws, dr);
+ *(u16 *)(dws->rx) = temp;
+ dws->rx += 2;
+ }
+
+ wait_till_not_busy(dws);
+ return dws->rx == dws->rx_end;
+}
+
+static void *next_transfer(struct dw_spi *dws)
+{
+ struct spi_message *msg = dws->cur_msg;
+ struct spi_transfer *trans = dws->cur_transfer;
+
+ /* Move to next transfer */
+ if (trans->transfer_list.next != &msg->transfers) {
+ dws->cur_transfer =
+ list_entry(trans->transfer_list.next,
+ struct spi_transfer,
+ transfer_list);
+ return RUNNING_STATE;
+ } else
+ return DONE_STATE;
+}
+
+/*
+ * Note: first step is the protocol driver prepares
+ * a dma-capable memory, and this func just need translate
+ * the virt addr to physical
+ */
+static int map_dma_buffers(struct dw_spi *dws)
+{
+ if (!dws->cur_msg->is_dma_mapped || !dws->dma_inited
+ || !dws->cur_chip->enable_dma)
+ return 0;
+
+ if (dws->cur_transfer->tx_dma)
+ dws->tx_dma = dws->cur_transfer->tx_dma;
+
+ if (dws->cur_transfer->rx_dma)
+ dws->rx_dma = dws->cur_transfer->rx_dma;
+
+ return 1;
+}
+
+/* Caller already set message->status; dma and pio irqs are blocked */
+static void giveback(struct dw_spi *dws)
+{
+ struct spi_transfer *last_transfer;
+ unsigned long flags;
+ struct spi_message *msg;
+
+ spin_lock_irqsave(&dws->lock, flags);
+ msg = dws->cur_msg;
+ dws->cur_msg = NULL;
+ dws->cur_transfer = NULL;
+ dws->prev_chip = dws->cur_chip;
+ dws->cur_chip = NULL;
+ dws->dma_mapped = 0;
+ queue_work(dws->workqueue, &dws->pump_messages);
+ spin_unlock_irqrestore(&dws->lock, flags);
+
+ last_transfer = list_entry(msg->transfers.prev,
+ struct spi_transfer,
+ transfer_list);
+
+ if (!last_transfer->cs_change)
+ dws->cs_control(MRST_SPI_DEASSERT);
+
+ msg->state = NULL;
+ if (msg->complete)
+ msg->complete(msg->context);
+}
+
+static void int_error_stop(struct dw_spi *dws, const char *msg)
+{
+ /* Stop and reset hw */
+ flush(dws);
+ spi_enable_chip(dws, 0);
+
+ dev_err(&dws->master->dev, "%s\n", msg);
+ dws->cur_msg->state = ERROR_STATE;
+ tasklet_schedule(&dws->pump_transfers);
+}
+
+static void transfer_complete(struct dw_spi *dws)
+{
+ /* Update total byte transfered return count actual bytes read */
+ dws->cur_msg->actual_length += dws->len;
+
+ /* Move to next transfer */
+ dws->cur_msg->state = next_transfer(dws);
+
+ /* Handle end of message */
+ if (dws->cur_msg->state == DONE_STATE) {
+ dws->cur_msg->status = 0;
+ giveback(dws);
+ } else
+ tasklet_schedule(&dws->pump_transfers);
+}
+
+static irqreturn_t interrupt_transfer(struct dw_spi *dws)
+{
+ u16 irq_status, irq_mask = 0x3f;
+
+ irq_status = dw_readw(dws, isr) & irq_mask;
+ /* Error handling */
+ if (irq_status & (SPI_INT_TXOI | SPI_INT_RXOI | SPI_INT_RXUI)) {
+ dw_readw(dws, txoicr);
+ dw_readw(dws, rxoicr);
+ dw_readw(dws, rxuicr);
+ int_error_stop(dws, "interrupt_transfer: fifo overrun");
+ return IRQ_HANDLED;
+ }
+
+ /* INT comes from tx */
+ if (dws->tx && (irq_status & SPI_INT_TXEI)) {
+ while (dws->tx < dws->tx_end)
+ dws->write(dws);
+
+ if (dws->tx == dws->tx_end) {
+ spi_mask_intr(dws, SPI_INT_TXEI);
+ transfer_complete(dws);
+ }
+ }
+
+ /* INT comes from rx */
+ if (dws->rx && (irq_status & SPI_INT_RXFI)) {
+ if (dws->read(dws))
+ transfer_complete(dws);
+ }
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t dw_spi_irq(int irq, void *dev_id)
+{
+ struct dw_spi *dws = dev_id;
+
+ if (!dws->cur_msg) {
+ spi_mask_intr(dws, SPI_INT_TXEI);
+ /* Never fail */
+ return IRQ_HANDLED;
+ }
+
+ return dws->transfer_handler(dws);
+}
+
+/* Must be called inside pump_transfers() */
+static void poll_transfer(struct dw_spi *dws)
+{
+ if (dws->tx) {
+ while (dws->write(dws))
+ dws->read(dws);
+ }
+
+ dws->read(dws);
+ transfer_complete(dws);
+}
+
+static void dma_transfer(struct dw_spi *dws, int cs_change)
+{
+}
+
+static void pump_transfers(unsigned long data)
+{
+ struct dw_spi *dws = (struct dw_spi *)data;
+ struct spi_message *message = NULL;
+ struct spi_transfer *transfer = NULL;
+ struct spi_transfer *previous = NULL;
+ struct spi_device *spi = NULL;
+ struct chip_data *chip = NULL;
+ u8 bits = 0;
+ u8 imask = 0;
+ u8 cs_change = 0;
+ u16 clk_div = 0;
+ u32 speed = 0;
+ u32 cr0 = 0;
+
+ /* Get current state information */
+ message = dws->cur_msg;
+ transfer = dws->cur_transfer;
+ chip = dws->cur_chip;
+ spi = message->spi;
+
+ if (message->state == ERROR_STATE) {
+ message->status = -EIO;
+ goto early_exit;
+ }
+
+ /* Handle end of message */
+ if (message->state == DONE_STATE) {
+ message->status = 0;
+ goto early_exit;
+ }
+
+ /* Delay if requested at end of transfer*/
+ if (message->state == RUNNING_STATE) {
+ previous = list_entry(transfer->transfer_list.prev,
+ struct spi_transfer,
+ transfer_list);
+ if (previous->delay_usecs)
+ udelay(previous->delay_usecs);
+ }
+
+ dws->n_bytes = chip->n_bytes;
+ dws->dma_width = chip->dma_width;
+ dws->cs_control = chip->cs_control;
+
+ dws->rx_dma = transfer->rx_dma;
+ dws->tx_dma = transfer->tx_dma;
+ dws->tx = (void *)transfer->tx_buf;
+ dws->tx_end = dws->tx + transfer->len;
+ dws->rx = transfer->rx_buf;
+ dws->rx_end = dws->rx + transfer->len;
+ dws->write = dws->tx ? chip->write : null_writer;
+ dws->read = dws->rx ? chip->read : null_reader;
+ dws->cs_change = transfer->cs_change;
+ dws->len = dws->cur_transfer->len;
+ if (chip != dws->prev_chip)
+ cs_change = 1;
+
+ cr0 = chip->cr0;
+
+ /* Handle per transfer options for bpw and speed */
+ if (transfer->speed_hz) {
+ speed = chip->speed_hz;
+
+ if (transfer->speed_hz != speed) {
+ speed = transfer->speed_hz;
+ if (speed > dws->max_freq) {
+ printk(KERN_ERR "MRST SPI0: unsupported"
+ "freq: %dHz\n", speed);
+ message->status = -EIO;
+ goto early_exit;
+ }
+
+ /* clk_div doesn't support odd number */
+ clk_div = dws->max_freq / speed;
+ clk_div = (clk_div >> 1) << 1;
+
+ chip->speed_hz = speed;
+ chip->clk_div = clk_div;
+ }
+ }
+ if (transfer->bits_per_word) {
+ bits = transfer->bits_per_word;
+
+ switch (bits) {
+ case 8:
+ dws->n_bytes = 1;
+ dws->dma_width = 1;
+ dws->read = (dws->read != null_reader) ?
+ u8_reader : null_reader;
+ dws->write = (dws->write != null_writer) ?
+ u8_writer : null_writer;
+ break;
+ case 16:
+ dws->n_bytes = 2;
+ dws->dma_width = 2;
+ dws->read = (dws->read != null_reader) ?
+ u16_reader : null_reader;
+ dws->write = (dws->write != null_writer) ?
+ u16_writer : null_writer;
+ break;
+ default:
+ printk(KERN_ERR "MRST SPI0: unsupported bits:"
+ "%db\n", bits);
+ message->status = -EIO;
+ goto early_exit;
+ }
+
+ cr0 = (bits - 1)
+ | (chip->type << SPI_FRF_OFFSET)
+ | (spi->mode << SPI_MODE_OFFSET)
+ | (chip->tmode << SPI_TMOD_OFFSET);
+ }
+ message->state = RUNNING_STATE;
+
+ /* Check if current transfer is a DMA transaction */
+ dws->dma_mapped = map_dma_buffers(dws);
+
+ if (!dws->dma_mapped && !chip->poll_mode) {
+ if (dws->rx)
+ imask |= SPI_INT_RXFI;
+ if (dws->tx)
+ imask |= SPI_INT_TXEI;
+ dws->transfer_handler = interrupt_transfer;
+ }
+
+ /*
+ * Reprogram registers only if
+ * 1. chip select changes
+ * 2. clk_div is changed
+ * 3. control value changes
+ */
+ if (dw_readw(dws, ctrl0) != cr0 || cs_change || clk_div) {
+ spi_enable_chip(dws, 0);
+
+ if (dw_readw(dws, ctrl0) != cr0)
+ dw_writew(dws, ctrl0, cr0);
+
+ /* Set the interrupt mask, for poll mode just diable all int */
+ spi_mask_intr(dws, 0xff);
+ if (!chip->poll_mode)
+ spi_umask_intr(dws, imask);
+
+ spi_set_clk(dws, clk_div ? clk_div : chip->clk_div);
+ spi_chip_sel(dws, spi->chip_select);
+ spi_enable_chip(dws, 1);
+
+ if (cs_change)
+ dws->prev_chip = chip;
+ }
+
+ if (dws->dma_mapped)
+ dma_transfer(dws, cs_change);
+
+ if (chip->poll_mode)
+ poll_transfer(dws);
+
+ return;
+
+early_exit:
+ giveback(dws);
+ return;
+}
+
+static void pump_messages(struct work_struct *work)
+{
+ struct dw_spi *dws =
+ container_of(work, struct dw_spi, pump_messages);
+ unsigned long flags;
+
+ /* Lock queue and check for queue work */
+ spin_lock_irqsave(&dws->lock, flags);
+ if (list_empty(&dws->queue) || dws->run == QUEUE_STOPPED) {
+ dws->busy = 0;
+ spin_unlock_irqrestore(&dws->lock, flags);
+ return;
+ }
+
+ /* Make sure we are not already running a message */
+ if (dws->cur_msg) {
+ spin_unlock_irqrestore(&dws->lock, flags);
+ return;
+ }
+
+ /* Extract head of queue */
+ dws->cur_msg = list_entry(dws->queue.next, struct spi_message, queue);
+ list_del_init(&dws->cur_msg->queue);
+
+ /* Initial message state*/
+ dws->cur_msg->state = START_STATE;
+ dws->cur_transfer = list_entry(dws->cur_msg->transfers.next,
+ struct spi_transfer,
+ transfer_list);
+ dws->cur_chip = spi_get_ctldata(dws->cur_msg->spi);
+
+ /* Mark as busy and launch transfers */
+ tasklet_schedule(&dws->pump_transfers);
+
+ dws->busy = 1;
+ spin_unlock_irqrestore(&dws->lock, flags);
+}
+
+/* spi_device use this to queue in their spi_msg */
+static int dw_spi_transfer(struct spi_device *spi, struct spi_message *msg)
+{
+ struct dw_spi *dws = spi_master_get_devdata(spi->master);
+ unsigned long flags;
+
+ spin_lock_irqsave(&dws->lock, flags);
+
+ if (dws->run == QUEUE_STOPPED) {
+ spin_unlock_irqrestore(&dws->lock, flags);
+ return -ESHUTDOWN;
+ }
+
+ msg->actual_length = 0;
+ msg->status = -EINPROGRESS;
+ msg->state = START_STATE;
+
+ list_add_tail(&msg->queue, &dws->queue);
+
+ if (dws->run == QUEUE_RUNNING && !dws->busy) {
+
+ if (dws->cur_transfer || dws->cur_msg)
+ queue_work(dws->workqueue,
+ &dws->pump_messages);
+ else {
+ /* If no other data transaction in air, just go */
+ spin_unlock_irqrestore(&dws->lock, flags);
+ pump_messages(&dws->pump_messages);
+ return 0;
+ }
+ }
+
+ spin_unlock_irqrestore(&dws->lock, flags);
+ return 0;
+}
+
+/* This may be called twice for each spi dev */
+static int dw_spi_setup(struct spi_device *spi)
+{
+ struct dw_spi_chip *chip_info = NULL;
+ struct chip_data *chip;
+
+ if (spi->bits_per_word != 8 && spi->bits_per_word != 16)
+ return -EINVAL;
+
+ /* Only alloc on first setup */
+ chip = spi_get_ctldata(spi);
+ if (!chip) {
+ chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
+ if (!chip)
+ return -ENOMEM;
+
+ chip->cs_control = null_cs_control;
+ chip->enable_dma = 0;
+ }
+
+ /*
+ * Protocol drivers may change the chip settings, so...
+ * if chip_info exists, use it
+ */
+ chip_info = spi->controller_data;
+
+ /* chip_info doesn't always exist */
+ if (chip_info) {
+ if (chip_info->cs_control)
+ chip->cs_control = chip_info->cs_control;
+
+ chip->poll_mode = chip_info->poll_mode;
+ chip->type = chip_info->type;
+
+ chip->rx_threshold = 0;
+ chip->tx_threshold = 0;
+
+ chip->enable_dma = chip_info->enable_dma;
+ }
+
+ if (spi->bits_per_word <= 8) {
+ chip->n_bytes = 1;
+ chip->dma_width = 1;
+ chip->read = u8_reader;
+ chip->write = u8_writer;
+ } else if (spi->bits_per_word <= 16) {
+ chip->n_bytes = 2;
+ chip->dma_width = 2;
+ chip->read = u16_reader;
+ chip->write = u16_writer;
+ } else {
+ /* Never take >16b case for MRST SPIC */
+ dev_err(&spi->dev, "invalid wordsize\n");
+ return -EINVAL;
+ }
+ chip->bits_per_word = spi->bits_per_word;
+
+ chip->speed_hz = spi->max_speed_hz;
+ if (chip->speed_hz)
+ chip->clk_div = 25000000 / chip->speed_hz;
+ else
+ chip->clk_div = 8; /* default value */
+
+ chip->tmode = 0; /* Tx & Rx */
+ /* Default SPI mode is SCPOL = 0, SCPH = 0 */
+ chip->cr0 = (chip->bits_per_word - 1)
+ | (chip->type << SPI_FRF_OFFSET)
+ | (spi->mode << SPI_MODE_OFFSET)
+ | (chip->tmode << SPI_TMOD_OFFSET);
+
+ spi_set_ctldata(spi, chip);
+ return 0;
+}
+
+static void dw_spi_cleanup(struct spi_device *spi)
+{
+ struct chip_data *chip = spi_get_ctldata(spi);
+ kfree(chip);
+}
+
+static int __init init_queue(struct dw_spi *dws)
+{
+ INIT_LIST_HEAD(&dws->queue);
+ spin_lock_init(&dws->lock);
+
+ dws->run = QUEUE_STOPPED;
+ dws->busy = 0;
+
+ tasklet_init(&dws->pump_transfers,
+ pump_transfers, (unsigned long)dws);
+
+ INIT_WORK(&dws->pump_messages, pump_messages);
+ dws->workqueue = create_singlethread_workqueue(
+ dev_name(dws->master->dev.parent));
+ if (dws->workqueue == NULL)
+ return -EBUSY;
+
+ return 0;
+}
+
+static int start_queue(struct dw_spi *dws)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&dws->lock, flags);
+
+ if (dws->run == QUEUE_RUNNING || dws->busy) {
+ spin_unlock_irqrestore(&dws->lock, flags);
+ return -EBUSY;
+ }
+
+ dws->run = QUEUE_RUNNING;
+ dws->cur_msg = NULL;
+ dws->cur_transfer = NULL;
+ dws->cur_chip = NULL;
+ dws->prev_chip = NULL;
+ spin_unlock_irqrestore(&dws->lock, flags);
+
+ queue_work(dws->workqueue, &dws->pump_messages);
+
+ return 0;
+}
+
+static int stop_queue(struct dw_spi *dws)
+{
+ unsigned long flags;
+ unsigned limit = 50;
+ int status = 0;
+
+ spin_lock_irqsave(&dws->lock, flags);
+ dws->run = QUEUE_STOPPED;
+ while (!list_empty(&dws->queue) && dws->busy && limit--) {
+ spin_unlock_irqrestore(&dws->lock, flags);
+ msleep(10);
+ spin_lock_irqsave(&dws->lock, flags);
+ }
+
+ if (!list_empty(&dws->queue) || dws->busy)
+ status = -EBUSY;
+ spin_unlock_irqrestore(&dws->lock, flags);
+
+ return status;
+}
+
+static int destroy_queue(struct dw_spi *dws)
+{
+ int status;
+
+ status = stop_queue(dws);
+ if (status != 0)
+ return status;
+ destroy_workqueue(dws->workqueue);
+ return 0;
+}
+
+/* Restart the controller, disable all interrupts, clean rx fifo */
+static void spi_hw_init(struct dw_spi *dws)
+{
+ spi_enable_chip(dws, 0);
+ spi_mask_intr(dws, 0xff);
+ spi_enable_chip(dws, 1);
+ flush(dws);
+}
+
+int __devinit dw_spi_add_host(struct dw_spi *dws)
+{
+ struct spi_master *master;
+ int ret;
+
+ BUG_ON(dws == NULL);
+
+ master = spi_alloc_master(dws->parent_dev, 0);
+ if (!master) {
+ ret = -ENOMEM;
+ goto exit;
+ }
+
+ dws->master = master;
+ dws->type = SSI_MOTO_SPI;
+ dws->prev_chip = NULL;
+ dws->dma_inited = 0;
+ dws->dma_addr = (dma_addr_t)(dws->paddr + 0x60);
+
+ ret = request_irq(dws->irq, dw_spi_irq, 0,
+ "dw_spi", dws);
+ if (ret < 0) {
+ dev_err(&master->dev, "can not get IRQ\n");
+ goto err_free_master;
+ }
+
+ master->mode_bits = SPI_CPOL | SPI_CPHA;
+ master->bus_num = dws->bus_num;
+ master->num_chipselect = dws->num_cs;
+ master->cleanup = dw_spi_cleanup;
+ master->setup = dw_spi_setup;
+ master->transfer = dw_spi_transfer;
+
+ dws->dma_inited = 0;
+
+ /* Basic HW init */
+ spi_hw_init(dws);
+
+ /* Initial and start queue */
+ ret = init_queue(dws);
+ if (ret) {
+ dev_err(&master->dev, "problem initializing queue\n");
+ goto err_diable_hw;
+ }
+ ret = start_queue(dws);
+ if (ret) {
+ dev_err(&master->dev, "problem starting queue\n");
+ goto err_diable_hw;
+ }
+
+ spi_master_set_devdata(master, dws);
+ ret = spi_register_master(master);
+ if (ret) {
+ dev_err(&master->dev, "problem registering spi master\n");
+ goto err_queue_alloc;
+ }
+
+ mrst_spi_debugfs_init(dws);
+ return 0;
+
+err_queue_alloc:
+ destroy_queue(dws);
+err_diable_hw:
+ spi_enable_chip(dws, 0);
+ free_irq(dws->irq, dws);
+err_free_master:
+ spi_master_put(master);
+exit:
+ return ret;
+}
+
+void __devexit dw_spi_remove_host(struct dw_spi *dws)
+{
+ int status = 0;
+
+ if (!dws)
+ return;
+ mrst_spi_debugfs_remove(dws);
+
+ /* Remove the queue */
+ status = destroy_queue(dws);
+ if (status != 0)
+ dev_err(&dws->master->dev, "dw_spi_remove: workqueue will not "
+ "complete, message memory not freed\n");
+
+ spi_enable_chip(dws, 0);
+ /* Disable clk */
+ spi_set_clk(dws, 0);
+ free_irq(dws->irq, dws);
+
+ /* Disconnect from the SPI framework */
+ spi_unregister_master(dws->master);
+}
+
+int dw_spi_suspend_host(struct dw_spi *dws)
+{
+ int ret = 0;
+
+ ret = stop_queue(dws);
+ if (ret)
+ return ret;
+ spi_enable_chip(dws, 0);
+ spi_set_clk(dws, 0);
+ return ret;
+}
+
+int dw_spi_resume_host(struct dw_spi *dws)
+{
+ int ret;
+
+ spi_hw_init(dws);
+ ret = start_queue(dws);
+ if (ret)
+ dev_err(&dws->master->dev, "fail to start queue (%d)\n", ret);
+ return ret;
+}
+
+MODULE_AUTHOR("Feng Tang <feng.tang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>");
+MODULE_DESCRIPTION("Driver for DesignWare SPI controller core");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/spi/dw_spi.h b/include/linux/spi/dw_spi.h
new file mode 100644
index 0000000..51b3e77
--- /dev/null
+++ b/include/linux/spi/dw_spi.h
@@ -0,0 +1,212 @@
+#ifndef DW_SPI_HEADER_H
+#define DW_SPI_HEADER_H
+#include <linux/io.h>
+
+/* Bit fields in CTRLR0 */
+#define SPI_DFS_OFFSET 0
+
+#define SPI_FRF_OFFSET 4
+#define SPI_FRF_SPI 0x0
+#define SPI_FRF_SSP 0x1
+#define SPI_FRF_MICROWIRE 0x2
+#define SPI_FRF_RESV 0x3
+
+#define SPI_MODE_OFFSET 6
+#define SPI_SCPH_OFFSET 6
+#define SPI_SCOL_OFFSET 7
+#define SPI_TMOD_OFFSET 8
+#define SPI_TMOD_TR 0x0 /* xmit & recv */
+#define SPI_TMOD_TO 0x1 /* xmit only */
+#define SPI_TMOD_RO 0x2 /* recv only */
+#define SPI_TMOD_EPROMREAD 0x3 /* eeprom read mode */
+
+#define SPI_SLVOE_OFFSET 10
+#define SPI_SRL_OFFSET 11
+#define SPI_CFS_OFFSET 12
+
+/* Bit fields in SR, 7 bits */
+#define SR_MASK 0x7f /* cover 7 bits */
+#define SR_BUSY (1 << 0)
+#define SR_TF_NOT_FULL (1 << 1)
+#define SR_TF_EMPT (1 << 2)
+#define SR_RF_NOT_EMPT (1 << 3)
+#define SR_RF_FULL (1 << 4)
+#define SR_TX_ERR (1 << 5)
+#define SR_DCOL (1 << 6)
+
+/* Bit fields in ISR, IMR, RISR, 7 bits */
+#define SPI_INT_TXEI (1 << 0)
+#define SPI_INT_TXOI (1 << 1)
+#define SPI_INT_RXUI (1 << 2)
+#define SPI_INT_RXOI (1 << 3)
+#define SPI_INT_RXFI (1 << 4)
+#define SPI_INT_MSTI (1 << 5)
+
+/* TX RX interrupt level threshhold, max can be 256 */
+#define SPI_INT_THRESHOLD 32
+
+enum dw_ssi_type {
+ SSI_MOTO_SPI = 0,
+ SSI_TI_SSP,
+ SSI_NS_MICROWIRE,
+};
+
+struct dw_spi_reg {
+ u32 ctrl0;
+ u32 ctrl1;
+ u32 ssienr;
+ u32 mwcr;
+ u32 ser;
+ u32 baudr;
+ u32 txfltr;
+ u32 rxfltr;
+ u32 txflr;
+ u32 rxflr;
+ u32 sr;
+ u32 imr;
+ u32 isr;
+ u32 risr;
+ u32 txoicr;
+ u32 rxoicr;
+ u32 rxuicr;
+ u32 msticr;
+ u32 icr;
+ u32 dmacr;
+ u32 dmatdlr;
+ u32 dmardlr;
+ u32 idr;
+ u32 version;
+ u32 dr; /* Currently oper as 32 bits,
+ though only low 16 bits matters */
+} __packed;
+
+struct dw_spi {
+ struct spi_master *master;
+ struct spi_device *cur_dev;
+ struct device *parent_dev;
+ enum dw_ssi_type type;
+
+ void __iomem *regs;
+ unsigned long paddr;
+ u32 iolen;
+ int irq;
+ u32 max_freq; /* max bus freq supported */
+
+ u16 bus_num;
+ u16 num_cs; /* supported slave numbers */
+
+ /* Driver message queue */
+ struct workqueue_struct *workqueue;
+ struct work_struct pump_messages;
+ spinlock_t lock;
+ struct list_head queue;
+ int busy;
+ int run;
+
+ /* Message Transfer pump */
+ struct tasklet_struct pump_transfers;
+
+ /* Current message transfer state info */
+ struct spi_message *cur_msg;
+ struct spi_transfer *cur_transfer;
+ struct chip_data *cur_chip;
+ struct chip_data *prev_chip;
+ size_t len;
+ void *tx;
+ void *tx_end;
+ void *rx;
+ void *rx_end;
+ int dma_mapped;
+ dma_addr_t rx_dma;
+ dma_addr_t tx_dma;
+ size_t rx_map_len;
+ size_t tx_map_len;
+ u8 n_bytes; /* current is a 1/2 bytes op */
+ u8 max_bits_per_word; /* maxim is 16b */
+ u32 dma_width;
+ int cs_change;
+ int (*write)(struct dw_spi *dws);
+ int (*read)(struct dw_spi *dws);
+ irqreturn_t (*transfer_handler)(struct dw_spi *dws);
+ void (*cs_control)(u32 command);
+
+ /* Dma info */
+ int dma_inited;
+ struct dma_chan *txchan;
+ struct dma_chan *rxchan;
+ int txdma_done;
+ int rxdma_done;
+ u64 tx_param;
+ u64 rx_param;
+ struct device *dma_dev;
+ dma_addr_t dma_addr;
+
+ /* Bus interface info */
+ void *priv;
+#ifdef CONFIG_DEBUG_FS
+ struct dentry *debugfs;
+#endif
+};
+
+#define dw_readl(dw, name) \
+ __raw_readl(&(((struct dw_spi_reg *)dw->regs)->name))
+#define dw_writel(dw, name, val) \
+ __raw_writel((val), &(((struct dw_spi_reg *)dw->regs)->name))
+#define dw_readw(dw, name) \
+ __raw_readw(&(((struct dw_spi_reg *)dw->regs)->name))
+#define dw_writew(dw, name, val) \
+ __raw_writew((val), &(((struct dw_spi_reg *)dw->regs)->name))
+
+static inline void spi_enable_chip(struct dw_spi *dws, int enable)
+{
+ dw_writel(dws, ssienr, (enable ? 1 : 0));
+}
+
+static inline void spi_set_clk(struct dw_spi *dws, u16 div)
+{
+ dw_writel(dws, baudr, div);
+}
+
+static inline void spi_chip_sel(struct dw_spi *dws, u16 cs)
+{
+ if (cs > dws->num_cs)
+ return;
+ dw_writel(dws, ser, 1 << cs);
+}
+
+/* Disable IRQ bits */
+static inline void spi_mask_intr(struct dw_spi *dws, u32 mask)
+{
+ u32 new_mask;
+
+ new_mask = dw_readl(dws, imr) & ~mask;
+ dw_writel(dws, imr, new_mask);
+}
+
+/* Enable IRQ bits */
+static inline void spi_umask_intr(struct dw_spi *dws, u32 mask)
+{
+ u32 new_mask;
+
+ new_mask = dw_readl(dws, imr) | mask;
+ dw_writel(dws, imr, new_mask);
+}
+
+/*
+ * Each SPI slave device to work with dw_api controller should
+ * has such a structure claiming its working mode (PIO/DMA etc),
+ * which can be save in the "controller_data" member of the
+ * struct spi_device
+ */
+struct dw_spi_chip {
+ u8 poll_mode; /* 0 for contoller polling mode */
+ u8 type; /* SPI/SSP/Micrwire */
+ u8 enable_dma;
+ void (*cs_control)(u32 command);
+};
+
+extern int dw_spi_add_host(struct dw_spi *dws);
+extern void dw_spi_remove_host(struct dw_spi *dws);
+extern int dw_spi_suspend_host(struct dw_spi *dws);
+extern int dw_spi_resume_host(struct dw_spi *dws);
+#endif /* DW_SPI_HEADER_H */
--
1.6.0.4
------------------------------------------------------------------------------
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^ permalink raw reply related [flat|nested] 2+ messages in thread* Re: [PATCH 1/3 v3]spi: controller driver for Designware SPI core
2009-10-12 6:19 [PATCH 1/3 v3]spi: controller driver for Designware SPI core Feng Tang
@ 2009-10-12 22:23 ` Andrew Morton
0 siblings, 0 replies; 2+ messages in thread
From: Andrew Morton @ 2009-10-12 22:23 UTC (permalink / raw)
To: Feng Tang; +Cc: spi-devel-list, David Brownell
On Mon, 12 Oct 2009 14:19:15 +0800
Feng Tang <feng.tang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> wrote:
> >From 2945f4eab344742d878ea10a774285fe770e6b10 Mon Sep 17 00:00:00 2001
> From: Feng Tang <feng.tang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> Date: Sat, 10 Oct 2009 14:55:48 +0800
> Subject: [PATCH 1/3] spi: controller driver for Designware SPI core
>
> Driver for the Designware SPI core, it supports multipul interfaces
> like PCI/APB etc. User can use "dw_apb_ssi_db.pdf" from Synopsys as
> HW datasheet.
>
> ...
>
> +#define START_STATE ((void *)0)
> +#define RUNNING_STATE ((void *)1)
> +#define DONE_STATE ((void *)2)
> +#define ERROR_STATE ((void *)-1)
What's going on here?
>
> ...
>
> +static void *next_transfer(struct dw_spi *dws)
> +{
> + struct spi_message *msg = dws->cur_msg;
> + struct spi_transfer *trans = dws->cur_transfer;
> +
> + /* Move to next transfer */
> + if (trans->transfer_list.next != &msg->transfers) {
> + dws->cur_transfer =
> + list_entry(trans->transfer_list.next,
> + struct spi_transfer,
> + transfer_list);
> + return RUNNING_STATE;
> + } else
> + return DONE_STATE;
> +}
Seems that you only need a single word of device-private storage in
`struct spi_message'. So instead of kmallocing enough memory to store
the `state' value, you've stuffed that value directly into the
spi_message, pretending to be a kernel address.
Correct?
If so, it's a bit nasty but probabyl a worthwhile thing to do. It'd be
nice to add a code comment somewhere explaining this. Plasing it at
the definition site of the *_STATE values would be appropriate.
------------------------------------------------------------------------------
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^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2009-10-12 22:23 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
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2009-10-12 6:19 [PATCH 1/3 v3]spi: controller driver for Designware SPI core Feng Tang
2009-10-12 22:23 ` Andrew Morton
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