+++ /dev/null
-/*
- * Freescale STMP378X SPI master driver
- *
- * Author: dmitry pervushin <dimka@embeddedalley.com>
- *
- * Copyright 2008 Freescale Semiconductor, Inc. All Rights Reserved.
- * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved.
- */
-
-/*
- * The code contained herein is licensed under the GNU General Public
- * License. You may obtain a copy of the GNU General Public License
- * Version 2 or later at the following locations:
- *
- * http://www.opensource.org/licenses/gpl-license.html
- * http://www.gnu.org/copyleft/gpl.html
- */
-#include <linux/module.h>
-#include <linux/init.h>
-#include <linux/interrupt.h>
-#include <linux/platform_device.h>
-#include <linux/spi/spi.h>
-#include <linux/err.h>
-#include <linux/clk.h>
-#include <linux/io.h>
-#include <linux/dma-mapping.h>
-#include <linux/delay.h>
-
-#include <mach/platform.h>
-#include <mach/stmp3xxx.h>
-#include <mach/dma.h>
-#include <mach/regs-ssp.h>
-#include <mach/regs-apbh.h>
-
-
-/* 0 means DMA mode(recommended, default), !0 - PIO mode */
-static int pio;
-static int clock;
-
-/* default timeout for busy waits is 2 seconds */
-#define STMP_SPI_TIMEOUT (2 * HZ)
-
-struct stmp_spi {
- int id;
-
- void * __iomem regs; /* vaddr of the control registers */
-
- int irq, err_irq;
- u32 dma;
- struct stmp3xxx_dma_descriptor d;
-
- u32 speed_khz;
- u32 saved_timings;
- u32 divider;
-
- struct clk *clk;
- struct device *master_dev;
-
- struct work_struct work;
- struct workqueue_struct *workqueue;
-
- /* lock protects queue access */
- spinlock_t lock;
- struct list_head queue;
-
- struct completion done;
-};
-
-#define busy_wait(cond) \
- ({ \
- unsigned long end_jiffies = jiffies + STMP_SPI_TIMEOUT; \
- bool succeeded = false; \
- do { \
- if (cond) { \
- succeeded = true; \
- break; \
- } \
- cpu_relax(); \
- } while (time_before(jiffies, end_jiffies)); \
- succeeded; \
- })
-
-/**
- * stmp_spi_init_hw
- * Initialize the SSP port
- */
-static int stmp_spi_init_hw(struct stmp_spi *ss)
-{
- int err = 0;
- void *pins = ss->master_dev->platform_data;
-
- err = stmp3xxx_request_pin_group(pins, dev_name(ss->master_dev));
- if (err)
- goto out;
-
- ss->clk = clk_get(NULL, "ssp");
- if (IS_ERR(ss->clk)) {
- err = PTR_ERR(ss->clk);
- goto out_free_pins;
- }
- clk_enable(ss->clk);
-
- stmp3xxx_reset_block(ss->regs, false);
- stmp3xxx_dma_reset_channel(ss->dma);
-
- return 0;
-
-out_free_pins:
- stmp3xxx_release_pin_group(pins, dev_name(ss->master_dev));
-out:
- return err;
-}
-
-static void stmp_spi_release_hw(struct stmp_spi *ss)
-{
- void *pins = ss->master_dev->platform_data;
-
- if (ss->clk && !IS_ERR(ss->clk)) {
- clk_disable(ss->clk);
- clk_put(ss->clk);
- }
- stmp3xxx_release_pin_group(pins, dev_name(ss->master_dev));
-}
-
-static int stmp_spi_setup_transfer(struct spi_device *spi,
- struct spi_transfer *t)
-{
- u8 bits_per_word;
- u32 hz;
- struct stmp_spi *ss = spi_master_get_devdata(spi->master);
- u16 rate;
-
- bits_per_word = spi->bits_per_word;
- if (t && t->bits_per_word)
- bits_per_word = t->bits_per_word;
-
- /*
- * Calculate speed:
- * - by default, use maximum speed from ssp clk
- * - if device overrides it, use it
- * - if transfer specifies other speed, use transfer's one
- */
- hz = 1000 * ss->speed_khz / ss->divider;
- if (spi->max_speed_hz)
- hz = min(hz, spi->max_speed_hz);
- if (t && t->speed_hz)
- hz = min(hz, t->speed_hz);
-
- if (hz == 0) {
- dev_err(&spi->dev, "Cannot continue with zero clock\n");
- return -EINVAL;
- }
-
- if (bits_per_word != 8) {
- dev_err(&spi->dev, "%s, unsupported bits_per_word=%d\n",
- __func__, bits_per_word);
- return -EINVAL;
- }
-
- dev_dbg(&spi->dev, "Requested clk rate = %uHz, max = %uHz/%d = %uHz\n",
- hz, ss->speed_khz, ss->divider,
- ss->speed_khz * 1000 / ss->divider);
-
- if (ss->speed_khz * 1000 / ss->divider < hz) {
- dev_err(&spi->dev, "%s, unsupported clock rate %uHz\n",
- __func__, hz);
- return -EINVAL;
- }
-
- rate = 1000 * ss->speed_khz/ss->divider/hz;
-
- writel(BF(ss->divider, SSP_TIMING_CLOCK_DIVIDE) |
- BF(rate - 1, SSP_TIMING_CLOCK_RATE),
- HW_SSP_TIMING + ss->regs);
-
- writel(BF(1 /* mode SPI */, SSP_CTRL1_SSP_MODE) |
- BF(4 /* 8 bits */, SSP_CTRL1_WORD_LENGTH) |
- ((spi->mode & SPI_CPOL) ? BM_SSP_CTRL1_POLARITY : 0) |
- ((spi->mode & SPI_CPHA) ? BM_SSP_CTRL1_PHASE : 0) |
- (pio ? 0 : BM_SSP_CTRL1_DMA_ENABLE),
- ss->regs + HW_SSP_CTRL1);
-
- return 0;
-}
-
-static int stmp_spi_setup(struct spi_device *spi)
-{
- /* spi_setup() does basic checks,
- * stmp_spi_setup_transfer() does more later
- */
- if (spi->bits_per_word != 8) {
- dev_err(&spi->dev, "%s, unsupported bits_per_word=%d\n",
- __func__, spi->bits_per_word);
- return -EINVAL;
- }
- return 0;
-}
-
-static inline u32 stmp_spi_cs(unsigned cs)
-{
- return ((cs & 1) ? BM_SSP_CTRL0_WAIT_FOR_CMD : 0) |
- ((cs & 2) ? BM_SSP_CTRL0_WAIT_FOR_IRQ : 0);
-}
-
-static int stmp_spi_txrx_dma(struct stmp_spi *ss, int cs,
- unsigned char *buf, dma_addr_t dma_buf, int len,
- int first, int last, bool write)
-{
- u32 c0 = 0;
- dma_addr_t spi_buf_dma = dma_buf;
- int status = 0;
- enum dma_data_direction dir = write ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
-
- c0 |= (first ? BM_SSP_CTRL0_LOCK_CS : 0);
- c0 |= (last ? BM_SSP_CTRL0_IGNORE_CRC : 0);
- c0 |= (write ? 0 : BM_SSP_CTRL0_READ);
- c0 |= BM_SSP_CTRL0_DATA_XFER;
-
- c0 |= stmp_spi_cs(cs);
-
- c0 |= BF(len, SSP_CTRL0_XFER_COUNT);
-
- if (!dma_buf)
- spi_buf_dma = dma_map_single(ss->master_dev, buf, len, dir);
-
- ss->d.command->cmd =
- BF(len, APBH_CHn_CMD_XFER_COUNT) |
- BF(1, APBH_CHn_CMD_CMDWORDS) |
- BM_APBH_CHn_CMD_WAIT4ENDCMD |
- BM_APBH_CHn_CMD_IRQONCMPLT |
- BF(write ? BV_APBH_CHn_CMD_COMMAND__DMA_READ :
- BV_APBH_CHn_CMD_COMMAND__DMA_WRITE,
- APBH_CHn_CMD_COMMAND);
- ss->d.command->pio_words[0] = c0;
- ss->d.command->buf_ptr = spi_buf_dma;
-
- stmp3xxx_dma_reset_channel(ss->dma);
- stmp3xxx_dma_clear_interrupt(ss->dma);
- stmp3xxx_dma_enable_interrupt(ss->dma);
- init_completion(&ss->done);
- stmp3xxx_dma_go(ss->dma, &ss->d, 1);
- wait_for_completion(&ss->done);
-
- if (!busy_wait(readl(ss->regs + HW_SSP_CTRL0) & BM_SSP_CTRL0_RUN))
- status = -ETIMEDOUT;
-
- if (!dma_buf)
- dma_unmap_single(ss->master_dev, spi_buf_dma, len, dir);
-
- return status;
-}
-
-static inline void stmp_spi_enable(struct stmp_spi *ss)
-{
- stmp3xxx_setl(BM_SSP_CTRL0_LOCK_CS, ss->regs + HW_SSP_CTRL0);
- stmp3xxx_clearl(BM_SSP_CTRL0_IGNORE_CRC, ss->regs + HW_SSP_CTRL0);
-}
-
-static inline void stmp_spi_disable(struct stmp_spi *ss)
-{
- stmp3xxx_clearl(BM_SSP_CTRL0_LOCK_CS, ss->regs + HW_SSP_CTRL0);
- stmp3xxx_setl(BM_SSP_CTRL0_IGNORE_CRC, ss->regs + HW_SSP_CTRL0);
-}
-
-static int stmp_spi_txrx_pio(struct stmp_spi *ss, int cs,
- unsigned char *buf, int len,
- bool first, bool last, bool write)
-{
- if (first)
- stmp_spi_enable(ss);
-
- stmp3xxx_setl(stmp_spi_cs(cs), ss->regs + HW_SSP_CTRL0);
-
- while (len--) {
- if (last && len <= 0)
- stmp_spi_disable(ss);
-
- stmp3xxx_clearl(BM_SSP_CTRL0_XFER_COUNT,
- ss->regs + HW_SSP_CTRL0);
- stmp3xxx_setl(1, ss->regs + HW_SSP_CTRL0);
-
- if (write)
- stmp3xxx_clearl(BM_SSP_CTRL0_READ,
- ss->regs + HW_SSP_CTRL0);
- else
- stmp3xxx_setl(BM_SSP_CTRL0_READ,
- ss->regs + HW_SSP_CTRL0);
-
- /* Run! */
- stmp3xxx_setl(BM_SSP_CTRL0_RUN, ss->regs + HW_SSP_CTRL0);
-
- if (!busy_wait(readl(ss->regs + HW_SSP_CTRL0) &
- BM_SSP_CTRL0_RUN))
- break;
-
- if (write)
- writel(*buf, ss->regs + HW_SSP_DATA);
-
- /* Set TRANSFER */
- stmp3xxx_setl(BM_SSP_CTRL0_DATA_XFER, ss->regs + HW_SSP_CTRL0);
-
- if (!write) {
- if (busy_wait((readl(ss->regs + HW_SSP_STATUS) &
- BM_SSP_STATUS_FIFO_EMPTY)))
- break;
- *buf = readl(ss->regs + HW_SSP_DATA) & 0xFF;
- }
-
- if (!busy_wait(readl(ss->regs + HW_SSP_CTRL0) &
- BM_SSP_CTRL0_RUN))
- break;
-
- /* advance to the next byte */
- buf++;
- }
-
- return len < 0 ? 0 : -ETIMEDOUT;
-}
-
-static int stmp_spi_handle_message(struct stmp_spi *ss, struct spi_message *m)
-{
- bool first, last;
- struct spi_transfer *t, *tmp_t;
- int status = 0;
- int cs;
-
- cs = m->spi->chip_select;
-
- list_for_each_entry_safe(t, tmp_t, &m->transfers, transfer_list) {
-
- first = (&t->transfer_list == m->transfers.next);
- last = (&t->transfer_list == m->transfers.prev);
-
- if (first || t->speed_hz || t->bits_per_word)
- stmp_spi_setup_transfer(m->spi, t);
-
- /* reject "not last" transfers which request to change cs */
- if (t->cs_change && !last) {
- dev_err(&m->spi->dev,
- "Message with t->cs_change has been skipped\n");
- continue;
- }
-
- if (t->tx_buf) {
- status = pio ?
- stmp_spi_txrx_pio(ss, cs, (void *)t->tx_buf,
- t->len, first, last, true) :
- stmp_spi_txrx_dma(ss, cs, (void *)t->tx_buf,
- t->tx_dma, t->len, first, last, true);
-#ifdef DEBUG
- if (t->len < 0x10)
- print_hex_dump_bytes("Tx ",
- DUMP_PREFIX_OFFSET,
- t->tx_buf, t->len);
- else
- pr_debug("Tx: %d bytes\n", t->len);
-#endif
- }
- if (t->rx_buf) {
- status = pio ?
- stmp_spi_txrx_pio(ss, cs, t->rx_buf,
- t->len, first, last, false) :
- stmp_spi_txrx_dma(ss, cs, t->rx_buf,
- t->rx_dma, t->len, first, last, false);
-#ifdef DEBUG
- if (t->len < 0x10)
- print_hex_dump_bytes("Rx ",
- DUMP_PREFIX_OFFSET,
- t->rx_buf, t->len);
- else
- pr_debug("Rx: %d bytes\n", t->len);
-#endif
- }
-
- if (t->delay_usecs)
- udelay(t->delay_usecs);
-
- if (status)
- break;
-
- }
- return status;
-}
-
-/**
- * stmp_spi_handle - handle messages from the queue
- */
-static void stmp_spi_handle(struct work_struct *w)
-{
- struct stmp_spi *ss = container_of(w, struct stmp_spi, work);
- unsigned long flags;
- struct spi_message *m;
-
- spin_lock_irqsave(&ss->lock, flags);
- while (!list_empty(&ss->queue)) {
- m = list_entry(ss->queue.next, struct spi_message, queue);
- list_del_init(&m->queue);
- spin_unlock_irqrestore(&ss->lock, flags);
-
- m->status = stmp_spi_handle_message(ss, m);
- m->complete(m->context);
-
- spin_lock_irqsave(&ss->lock, flags);
- }
- spin_unlock_irqrestore(&ss->lock, flags);
-
- return;
-}
-
-/**
- * stmp_spi_transfer - perform message transfer.
- * Called indirectly from spi_async, queues all the messages to
- * spi_handle_message.
- * @spi: spi device
- * @m: message to be queued
- */
-static int stmp_spi_transfer(struct spi_device *spi, struct spi_message *m)
-{
- struct stmp_spi *ss = spi_master_get_devdata(spi->master);
- unsigned long flags;
-
- m->status = -EINPROGRESS;
- spin_lock_irqsave(&ss->lock, flags);
- list_add_tail(&m->queue, &ss->queue);
- queue_work(ss->workqueue, &ss->work);
- spin_unlock_irqrestore(&ss->lock, flags);
- return 0;
-}
-
-static irqreturn_t stmp_spi_irq(int irq, void *dev_id)
-{
- struct stmp_spi *ss = dev_id;
-
- stmp3xxx_dma_clear_interrupt(ss->dma);
- complete(&ss->done);
- return IRQ_HANDLED;
-}
-
-static irqreturn_t stmp_spi_irq_err(int irq, void *dev_id)
-{
- struct stmp_spi *ss = dev_id;
- u32 c1, st;
-
- c1 = readl(ss->regs + HW_SSP_CTRL1);
- st = readl(ss->regs + HW_SSP_STATUS);
- dev_err(ss->master_dev, "%s: status = 0x%08X, c1 = 0x%08X\n",
- __func__, st, c1);
- stmp3xxx_clearl(c1 & 0xCCCC0000, ss->regs + HW_SSP_CTRL1);
-
- return IRQ_HANDLED;
-}
-
-static int __devinit stmp_spi_probe(struct platform_device *dev)
-{
- int err = 0;
- struct spi_master *master;
- struct stmp_spi *ss;
- struct resource *r;
-
- master = spi_alloc_master(&dev->dev, sizeof(struct stmp_spi));
- if (master == NULL) {
- err = -ENOMEM;
- goto out0;
- }
- master->flags = SPI_MASTER_HALF_DUPLEX;
-
- ss = spi_master_get_devdata(master);
- platform_set_drvdata(dev, master);
-
- /* Get resources(memory, IRQ) associated with the device */
- r = platform_get_resource(dev, IORESOURCE_MEM, 0);
- if (r == NULL) {
- err = -ENODEV;
- goto out_put_master;
- }
- ss->regs = ioremap(r->start, resource_size(r));
- if (!ss->regs) {
- err = -EINVAL;
- goto out_put_master;
- }
-
- ss->master_dev = &dev->dev;
- ss->id = dev->id;
-
- INIT_WORK(&ss->work, stmp_spi_handle);
- INIT_LIST_HEAD(&ss->queue);
- spin_lock_init(&ss->lock);
-
- ss->workqueue = create_singlethread_workqueue(dev_name(&dev->dev));
- if (!ss->workqueue) {
- err = -ENXIO;
- goto out_put_master;
- }
- master->transfer = stmp_spi_transfer;
- master->setup = stmp_spi_setup;
-
- /* the spi->mode bits understood by this driver: */
- master->mode_bits = SPI_CPOL | SPI_CPHA;
-
- ss->irq = platform_get_irq(dev, 0);
- if (ss->irq < 0) {
- err = ss->irq;
- goto out_put_master;
- }
- ss->err_irq = platform_get_irq(dev, 1);
- if (ss->err_irq < 0) {
- err = ss->err_irq;
- goto out_put_master;
- }
-
- r = platform_get_resource(dev, IORESOURCE_DMA, 0);
- if (r == NULL) {
- err = -ENODEV;
- goto out_put_master;
- }
-
- ss->dma = r->start;
- err = stmp3xxx_dma_request(ss->dma, &dev->dev, dev_name(&dev->dev));
- if (err)
- goto out_put_master;
-
- err = stmp3xxx_dma_allocate_command(ss->dma, &ss->d);
- if (err)
- goto out_free_dma;
-
- master->bus_num = dev->id;
- master->num_chipselect = 1;
-
- /* SPI controller initializations */
- err = stmp_spi_init_hw(ss);
- if (err) {
- dev_dbg(&dev->dev, "cannot initialize hardware\n");
- goto out_free_dma_desc;
- }
-
- if (clock) {
- dev_info(&dev->dev, "clock rate forced to %d\n", clock);
- clk_set_rate(ss->clk, clock);
- }
- ss->speed_khz = clk_get_rate(ss->clk);
- ss->divider = 2;
- dev_info(&dev->dev, "max possible speed %d = %ld/%d kHz\n",
- ss->speed_khz, clk_get_rate(ss->clk), ss->divider);
-
- /* Register for SPI interrupt */
- err = request_irq(ss->irq, stmp_spi_irq, 0,
- dev_name(&dev->dev), ss);
- if (err) {
- dev_dbg(&dev->dev, "request_irq failed, %d\n", err);
- goto out_release_hw;
- }
-
- /* ..and shared interrupt for all SSP controllers */
- err = request_irq(ss->err_irq, stmp_spi_irq_err, IRQF_SHARED,
- dev_name(&dev->dev), ss);
- if (err) {
- dev_dbg(&dev->dev, "request_irq(error) failed, %d\n", err);
- goto out_free_irq;
- }
-
- err = spi_register_master(master);
- if (err) {
- dev_dbg(&dev->dev, "cannot register spi master, %d\n", err);
- goto out_free_irq_2;
- }
- dev_info(&dev->dev, "at (mapped) 0x%08X, irq=%d, bus %d, %s mode\n",
- (u32)ss->regs, ss->irq, master->bus_num,
- pio ? "PIO" : "DMA");
- return 0;
-
-out_free_irq_2:
- free_irq(ss->err_irq, ss);
-out_free_irq:
- free_irq(ss->irq, ss);
-out_free_dma_desc:
- stmp3xxx_dma_free_command(ss->dma, &ss->d);
-out_free_dma:
- stmp3xxx_dma_release(ss->dma);
-out_release_hw:
- stmp_spi_release_hw(ss);
-out_put_master:
- if (ss->workqueue)
- destroy_workqueue(ss->workqueue);
- if (ss->regs)
- iounmap(ss->regs);
- platform_set_drvdata(dev, NULL);
- spi_master_put(master);
-out0:
- return err;
-}
-
-static int __devexit stmp_spi_remove(struct platform_device *dev)
-{
- struct stmp_spi *ss;
- struct spi_master *master;
-
- master = spi_master_get(platform_get_drvdata(dev));
- ss = spi_master_get_devdata(master);
-
- spi_unregister_master(master);
-
- free_irq(ss->err_irq, ss);
- free_irq(ss->irq, ss);
- stmp3xxx_dma_free_command(ss->dma, &ss->d);
- stmp3xxx_dma_release(ss->dma);
- stmp_spi_release_hw(ss);
- destroy_workqueue(ss->workqueue);
- iounmap(ss->regs);
- spi_master_put(master);
- return 0;
-}
-
-#ifdef CONFIG_PM
-static int stmp_spi_suspend(struct platform_device *pdev, pm_message_t pmsg)
-{
- struct stmp_spi *ss;
- struct spi_master *master;
-
- master = platform_get_drvdata(pdev);
- ss = spi_master_get_devdata(master);
-
- ss->saved_timings = readl(HW_SSP_TIMING + ss->regs);
- clk_disable(ss->clk);
-
- return 0;
-}
-
-static int stmp_spi_resume(struct platform_device *pdev)
-{
- struct stmp_spi *ss;
- struct spi_master *master;
-
- master = platform_get_drvdata(pdev);
- ss = spi_master_get_devdata(master);
-
- clk_enable(ss->clk);
- stmp3xxx_reset_block(ss->regs, false);
- writel(ss->saved_timings, ss->regs + HW_SSP_TIMING);
-
- return 0;
-}
-
-#else
-#define stmp_spi_suspend NULL
-#define stmp_spi_resume NULL
-#endif
-
-static struct platform_driver stmp_spi_driver = {
- .probe = stmp_spi_probe,
- .remove = __devexit_p(stmp_spi_remove),
- .driver = {
- .name = "stmp3xxx_ssp",
- .owner = THIS_MODULE,
- },
- .suspend = stmp_spi_suspend,
- .resume = stmp_spi_resume,
-};
-module_platform_driver(stmp_spi_driver);
-
-module_param(pio, int, S_IRUGO);
-module_param(clock, int, S_IRUGO);
-MODULE_AUTHOR("dmitry pervushin <dpervushin@embeddedalley.com>");
-MODULE_DESCRIPTION("STMP3xxx SPI/SSP driver");
-MODULE_LICENSE("GPL");
projects / profile / ivi / kernel-adaptation-intel-automotive.git / commitdiff