diff options
Diffstat (limited to 'drivers/spi/spi-stmp.c')
| -rw-r--r-- | drivers/spi/spi-stmp.c | 664 |
1 files changed, 0 insertions, 664 deletions
diff --git a/drivers/spi/spi-stmp.c b/drivers/spi/spi-stmp.c deleted file mode 100644 index 911e904b3c84..000000000000 --- a/drivers/spi/spi-stmp.c +++ /dev/null @@ -1,664 +0,0 @@ -/* - * 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"); |