diff options
Diffstat (limited to 'drivers/spi/spi-bcm63xx.c')
| -rw-r--r-- | drivers/spi/spi-bcm63xx.c | 347 |
1 files changed, 151 insertions, 196 deletions
diff --git a/drivers/spi/spi-bcm63xx.c b/drivers/spi/spi-bcm63xx.c index a9f4049c676..8510400e786 100644 --- a/drivers/spi/spi-bcm63xx.c +++ b/drivers/spi/spi-bcm63xx.c @@ -20,7 +20,6 @@ */ #include <linux/kernel.h> -#include <linux/init.h> #include <linux/clk.h> #include <linux/io.h> #include <linux/module.h> @@ -30,13 +29,11 @@ #include <linux/spi/spi.h> #include <linux/completion.h> #include <linux/err.h> -#include <linux/workqueue.h> #include <linux/pm_runtime.h> #include <bcm63xx_dev_spi.h> -#define PFX KBUILD_MODNAME -#define DRV_VER "0.1.2" +#define BCM63XX_SPI_MAX_PREPEND 15 struct bcm63xx_spi { struct completion done; @@ -45,21 +42,14 @@ struct bcm63xx_spi { int irq; /* Platform data */ - u32 speed_hz; unsigned fifo_size; unsigned int msg_type_shift; unsigned int msg_ctl_width; - /* Data buffers */ - const unsigned char *tx_ptr; - unsigned char *rx_ptr; - /* data iomem */ u8 __iomem *tx_io; const u8 __iomem *rx_io; - int remaining_bytes; - struct clk *clk; struct platform_device *pdev; }; @@ -98,40 +88,16 @@ static const unsigned bcm63xx_spi_freq_table[SPI_CLK_MASK][2] = { { 391000, SPI_CLK_0_391MHZ } }; -static int bcm63xx_spi_check_transfer(struct spi_device *spi, - struct spi_transfer *t) -{ - u8 bits_per_word; - - bits_per_word = (t) ? t->bits_per_word : spi->bits_per_word; - if (bits_per_word != 8) { - dev_err(&spi->dev, "%s, unsupported bits_per_word=%d\n", - __func__, bits_per_word); - return -EINVAL; - } - - if (spi->chip_select > spi->master->num_chipselect) { - dev_err(&spi->dev, "%s, unsupported slave %d\n", - __func__, spi->chip_select); - return -EINVAL; - } - - return 0; -} - static void bcm63xx_spi_setup_transfer(struct spi_device *spi, struct spi_transfer *t) { struct bcm63xx_spi *bs = spi_master_get_devdata(spi->master); - u32 hz; u8 clk_cfg, reg; int i; - hz = (t) ? t->speed_hz : spi->max_speed_hz; - /* Find the closest clock configuration */ for (i = 0; i < SPI_CLK_MASK; i++) { - if (hz >= bcm63xx_spi_freq_table[i][0]) { + if (t->speed_hz >= bcm63xx_spi_freq_table[i][0]) { clk_cfg = bcm63xx_spi_freq_table[i][1]; break; } @@ -148,59 +114,23 @@ static void bcm63xx_spi_setup_transfer(struct spi_device *spi, bcm_spi_writeb(bs, reg, SPI_CLK_CFG); dev_dbg(&spi->dev, "Setting clock register to %02x (hz %d)\n", - clk_cfg, hz); + clk_cfg, t->speed_hz); } /* the spi->mode bits understood by this driver: */ #define MODEBITS (SPI_CPOL | SPI_CPHA) -static int bcm63xx_spi_setup(struct spi_device *spi) -{ - struct bcm63xx_spi *bs; - int ret; - - bs = spi_master_get_devdata(spi->master); - - if (!spi->bits_per_word) - spi->bits_per_word = 8; - - if (spi->mode & ~MODEBITS) { - dev_err(&spi->dev, "%s, unsupported mode bits %x\n", - __func__, spi->mode & ~MODEBITS); - return -EINVAL; - } - - ret = bcm63xx_spi_check_transfer(spi, NULL); - if (ret < 0) { - dev_err(&spi->dev, "setup: unsupported mode bits %x\n", - spi->mode & ~MODEBITS); - return ret; - } - - dev_dbg(&spi->dev, "%s, mode %d, %u bits/w, %u nsec/bit\n", - __func__, spi->mode & MODEBITS, spi->bits_per_word, 0); - - return 0; -} - -/* Fill the TX FIFO with as many bytes as possible */ -static void bcm63xx_spi_fill_tx_fifo(struct bcm63xx_spi *bs) -{ - u8 size; - - /* Fill the Tx FIFO with as many bytes as possible */ - size = bs->remaining_bytes < bs->fifo_size ? bs->remaining_bytes : - bs->fifo_size; - memcpy_toio(bs->tx_io, bs->tx_ptr, size); - bs->remaining_bytes -= size; -} - -static unsigned int bcm63xx_txrx_bufs(struct spi_device *spi, - struct spi_transfer *t) +static int bcm63xx_txrx_bufs(struct spi_device *spi, struct spi_transfer *first, + unsigned int num_transfers) { struct bcm63xx_spi *bs = spi_master_get_devdata(spi->master); u16 msg_ctl; u16 cmd; + u8 rx_tail; + unsigned int i, timeout = 0, prepend_len = 0, len = 0; + struct spi_transfer *t = first; + bool do_rx = false; + bool do_tx = false; /* Disable the CMD_DONE interrupt */ bcm_spi_writeb(bs, 0, SPI_INT_MASK); @@ -208,25 +138,43 @@ static unsigned int bcm63xx_txrx_bufs(struct spi_device *spi, dev_dbg(&spi->dev, "txrx: tx %p, rx %p, len %d\n", t->tx_buf, t->rx_buf, t->len); - /* Transmitter is inhibited */ - bs->tx_ptr = t->tx_buf; - bs->rx_ptr = t->rx_buf; + if (num_transfers > 1 && t->tx_buf && t->len <= BCM63XX_SPI_MAX_PREPEND) + prepend_len = t->len; + + /* prepare the buffer */ + for (i = 0; i < num_transfers; i++) { + if (t->tx_buf) { + do_tx = true; + memcpy_toio(bs->tx_io + len, t->tx_buf, t->len); + + /* don't prepend more than one tx */ + if (t != first) + prepend_len = 0; + } + + if (t->rx_buf) { + do_rx = true; + /* prepend is half-duplex write only */ + if (t == first) + prepend_len = 0; + } + + len += t->len; - if (t->tx_buf) { - bs->remaining_bytes = t->len; - bcm63xx_spi_fill_tx_fifo(bs); + t = list_entry(t->transfer_list.next, struct spi_transfer, + transfer_list); } - init_completion(&bs->done); + reinit_completion(&bs->done); /* Fill in the Message control register */ - msg_ctl = (t->len << SPI_BYTE_CNT_SHIFT); + msg_ctl = (len << SPI_BYTE_CNT_SHIFT); - if (t->rx_buf && t->tx_buf) + if (do_rx && do_tx && prepend_len == 0) msg_ctl |= (SPI_FD_RW << bs->msg_type_shift); - else if (t->rx_buf) + else if (do_rx) msg_ctl |= (SPI_HD_R << bs->msg_type_shift); - else if (t->tx_buf) + else if (do_tx) msg_ctl |= (SPI_HD_W << bs->msg_type_shift); switch (bs->msg_ctl_width) { @@ -240,30 +188,33 @@ static unsigned int bcm63xx_txrx_bufs(struct spi_device *spi, /* Issue the transfer */ cmd = SPI_CMD_START_IMMEDIATE; - cmd |= (0 << SPI_CMD_PREPEND_BYTE_CNT_SHIFT); + cmd |= (prepend_len << SPI_CMD_PREPEND_BYTE_CNT_SHIFT); cmd |= (spi->chip_select << SPI_CMD_DEVICE_ID_SHIFT); bcm_spi_writew(bs, cmd, SPI_CMD); /* Enable the CMD_DONE interrupt */ bcm_spi_writeb(bs, SPI_INTR_CMD_DONE, SPI_INT_MASK); - return t->len - bs->remaining_bytes; -} + timeout = wait_for_completion_timeout(&bs->done, HZ); + if (!timeout) + return -ETIMEDOUT; -static int bcm63xx_spi_prepare_transfer(struct spi_master *master) -{ - struct bcm63xx_spi *bs = spi_master_get_devdata(master); + if (!do_rx) + return 0; - pm_runtime_get_sync(&bs->pdev->dev); + len = 0; + t = first; + /* Read out all the data */ + for (i = 0; i < num_transfers; i++) { + if (t->rx_buf) + memcpy_fromio(t->rx_buf, bs->rx_io + len, t->len); - return 0; -} - -static int bcm63xx_spi_unprepare_transfer(struct spi_master *master) -{ - struct bcm63xx_spi *bs = spi_master_get_devdata(master); + if (t != first || prepend_len == 0) + len += t->len; - pm_runtime_put(&bs->pdev->dev); + t = list_entry(t->transfer_list.next, struct spi_transfer, + transfer_list); + } return 0; } @@ -272,41 +223,72 @@ static int bcm63xx_spi_transfer_one(struct spi_master *master, struct spi_message *m) { struct bcm63xx_spi *bs = spi_master_get_devdata(master); - struct spi_transfer *t; + struct spi_transfer *t, *first = NULL; struct spi_device *spi = m->spi; int status = 0; - unsigned int timeout = 0; - + unsigned int n_transfers = 0, total_len = 0; + bool can_use_prepend = false; + + /* + * This SPI controller does not support keeping CS active after a + * transfer. + * Work around this by merging as many transfers we can into one big + * full-duplex transfers. + */ list_for_each_entry(t, &m->transfers, transfer_list) { - unsigned int len = t->len; - u8 rx_tail; + if (!first) + first = t; + + n_transfers++; + total_len += t->len; + + if (n_transfers == 2 && !first->rx_buf && !t->tx_buf && + first->len <= BCM63XX_SPI_MAX_PREPEND) + can_use_prepend = true; + else if (can_use_prepend && t->tx_buf) + can_use_prepend = false; + + /* we can only transfer one fifo worth of data */ + if ((can_use_prepend && + total_len > (bs->fifo_size + BCM63XX_SPI_MAX_PREPEND)) || + (!can_use_prepend && total_len > bs->fifo_size)) { + dev_err(&spi->dev, "unable to do transfers larger than FIFO size (%i > %i)\n", + total_len, bs->fifo_size); + status = -EINVAL; + goto exit; + } - status = bcm63xx_spi_check_transfer(spi, t); - if (status < 0) + /* all combined transfers have to have the same speed */ + if (t->speed_hz != first->speed_hz) { + dev_err(&spi->dev, "unable to change speed between transfers\n"); + status = -EINVAL; goto exit; + } - /* configure adapter for a new transfer */ - bcm63xx_spi_setup_transfer(spi, t); + /* CS will be deasserted directly after transfer */ + if (t->delay_usecs) { + dev_err(&spi->dev, "unable to keep CS asserted after transfer\n"); + status = -EINVAL; + goto exit; + } - while (len) { - /* send the data */ - len -= bcm63xx_txrx_bufs(spi, t); + if (t->cs_change || + list_is_last(&t->transfer_list, &m->transfers)) { + /* configure adapter for a new transfer */ + bcm63xx_spi_setup_transfer(spi, first); - timeout = wait_for_completion_timeout(&bs->done, HZ); - if (!timeout) { - status = -ETIMEDOUT; + /* send the data */ + status = bcm63xx_txrx_bufs(spi, first, n_transfers); + if (status) goto exit; - } - /* read out all data */ - rx_tail = bcm_spi_readb(bs, SPI_RX_TAIL); + m->actual_length += total_len; - /* Read out all the data */ - if (rx_tail) - memcpy_fromio(bs->rx_ptr, bs->rx_io, rx_tail); + first = NULL; + n_transfers = 0; + total_len = 0; + can_use_prepend = false; } - - m->actual_length += t->len; } exit: m->status = status; @@ -337,62 +319,45 @@ static irqreturn_t bcm63xx_spi_interrupt(int irq, void *dev_id) } -static int __devinit bcm63xx_spi_probe(struct platform_device *pdev) +static int bcm63xx_spi_probe(struct platform_device *pdev) { struct resource *r; struct device *dev = &pdev->dev; - struct bcm63xx_spi_pdata *pdata = pdev->dev.platform_data; + struct bcm63xx_spi_pdata *pdata = dev_get_platdata(&pdev->dev); int irq; struct spi_master *master; struct clk *clk; struct bcm63xx_spi *bs; int ret; - r = platform_get_resource(pdev, IORESOURCE_MEM, 0); - if (!r) { - dev_err(dev, "no iomem\n"); - ret = -ENXIO; - goto out; - } - irq = platform_get_irq(pdev, 0); if (irq < 0) { dev_err(dev, "no irq\n"); - ret = -ENXIO; - goto out; + return -ENXIO; } - clk = clk_get(dev, "spi"); + clk = devm_clk_get(dev, "spi"); if (IS_ERR(clk)) { dev_err(dev, "no clock for device\n"); - ret = PTR_ERR(clk); - goto out; + return PTR_ERR(clk); } master = spi_alloc_master(dev, sizeof(*bs)); if (!master) { dev_err(dev, "out of memory\n"); - ret = -ENOMEM; - goto out_clk; + return -ENOMEM; } bs = spi_master_get_devdata(master); + init_completion(&bs->done); platform_set_drvdata(pdev, master); bs->pdev = pdev; - if (!devm_request_mem_region(&pdev->dev, r->start, - resource_size(r), PFX)) { - dev_err(dev, "iomem request failed\n"); - ret = -ENXIO; - goto out_err; - } - - bs->regs = devm_ioremap_nocache(&pdev->dev, r->start, - resource_size(r)); - if (!bs->regs) { - dev_err(dev, "unable to ioremap regs\n"); - ret = -ENOMEM; + r = platform_get_resource(pdev, IORESOURCE_MEM, 0); + bs->regs = devm_ioremap_resource(&pdev->dev, r); + if (IS_ERR(bs->regs)) { + ret = PTR_ERR(bs->regs); goto out_err; } @@ -409,12 +374,10 @@ static int __devinit bcm63xx_spi_probe(struct platform_device *pdev) master->bus_num = pdata->bus_num; master->num_chipselect = pdata->num_chipselect; - master->setup = bcm63xx_spi_setup; - master->prepare_transfer_hardware = bcm63xx_spi_prepare_transfer; - master->unprepare_transfer_hardware = bcm63xx_spi_unprepare_transfer; master->transfer_one_message = bcm63xx_spi_transfer_one; master->mode_bits = MODEBITS; - bs->speed_hz = pdata->speed_hz; + master->bits_per_word_mask = SPI_BPW_MASK(8); + master->auto_runtime_pm = true; bs->msg_type_shift = pdata->msg_type_shift; bs->msg_ctl_width = pdata->msg_ctl_width; bs->tx_io = (u8 *)(bs->regs + bcm63xx_spireg(SPI_MSG_DATA)); @@ -427,98 +390,90 @@ static int __devinit bcm63xx_spi_probe(struct platform_device *pdev) default: dev_err(dev, "unsupported MSG_CTL width: %d\n", bs->msg_ctl_width); - goto out_clk_disable; + goto out_err; } /* Initialize hardware */ - clk_enable(bs->clk); + ret = clk_prepare_enable(bs->clk); + if (ret) + goto out_err; + bcm_spi_writeb(bs, SPI_INTR_CLEAR_ALL, SPI_INT_STATUS); /* register and we are done */ - ret = spi_register_master(master); + ret = devm_spi_register_master(dev, master); if (ret) { dev_err(dev, "spi register failed\n"); goto out_clk_disable; } - dev_info(dev, "at 0x%08x (irq %d, FIFOs size %d) v%s\n", - r->start, irq, bs->fifo_size, DRV_VER); + dev_info(dev, "at 0x%08x (irq %d, FIFOs size %d)\n", + r->start, irq, bs->fifo_size); return 0; out_clk_disable: - clk_disable(clk); + clk_disable_unprepare(clk); out_err: - platform_set_drvdata(pdev, NULL); spi_master_put(master); -out_clk: - clk_put(clk); -out: return ret; } -static int __devexit bcm63xx_spi_remove(struct platform_device *pdev) +static int bcm63xx_spi_remove(struct platform_device *pdev) { - struct spi_master *master = spi_master_get(platform_get_drvdata(pdev)); + struct spi_master *master = platform_get_drvdata(pdev); struct bcm63xx_spi *bs = spi_master_get_devdata(master); - spi_unregister_master(master); - /* reset spi block */ bcm_spi_writeb(bs, 0, SPI_INT_MASK); /* HW shutdown */ - clk_disable(bs->clk); - clk_put(bs->clk); - - platform_set_drvdata(pdev, 0); - - spi_master_put(master); + clk_disable_unprepare(bs->clk); return 0; } -#ifdef CONFIG_PM +#ifdef CONFIG_PM_SLEEP static int bcm63xx_spi_suspend(struct device *dev) { - struct spi_master *master = - platform_get_drvdata(to_platform_device(dev)); + struct spi_master *master = dev_get_drvdata(dev); struct bcm63xx_spi *bs = spi_master_get_devdata(master); - clk_disable(bs->clk); + spi_master_suspend(master); + + clk_disable_unprepare(bs->clk); return 0; } static int bcm63xx_spi_resume(struct device *dev) { - struct spi_master *master = - platform_get_drvdata(to_platform_device(dev)); + struct spi_master *master = dev_get_drvdata(dev); struct bcm63xx_spi *bs = spi_master_get_devdata(master); + int ret; - clk_enable(bs->clk); + ret = clk_prepare_enable(bs->clk); + if (ret) + return ret; + + spi_master_resume(master); return 0; } +#endif static const struct dev_pm_ops bcm63xx_spi_pm_ops = { - .suspend = bcm63xx_spi_suspend, - .resume = bcm63xx_spi_resume, + SET_SYSTEM_SLEEP_PM_OPS(bcm63xx_spi_suspend, bcm63xx_spi_resume) }; -#define BCM63XX_SPI_PM_OPS (&bcm63xx_spi_pm_ops) -#else -#define BCM63XX_SPI_PM_OPS NULL -#endif - static struct platform_driver bcm63xx_spi_driver = { .driver = { .name = "bcm63xx-spi", .owner = THIS_MODULE, - .pm = BCM63XX_SPI_PM_OPS, + .pm = &bcm63xx_spi_pm_ops, }, .probe = bcm63xx_spi_probe, - .remove = __devexit_p(bcm63xx_spi_remove), + .remove = bcm63xx_spi_remove, }; module_platform_driver(bcm63xx_spi_driver); |
