From 7e9955567eadb83642be55e6ae5853412dd48d14 Mon Sep 17 00:00:00 2001 From: Girish K S Date: Mon, 20 May 2013 12:21:32 +0530 Subject: spi: s3c64xx: added support for polling mode The 64xx spi driver supports partial polling mode. Only the last chunk of the transfer length is transferred or recieved in polling mode. Some SoC's that adopt this controller might not have have dma interface. This patch adds support for complete polling mode and gives flexibity for the user to select poll/dma mode. Signed-off-by: Girish K S Signed-off-by: Mark Brown --- drivers/spi/spi-s3c64xx.c | 153 +++++++++++++++++++++++++++++++--------------- 1 file changed, 104 insertions(+), 49 deletions(-) (limited to 'drivers/spi/spi-s3c64xx.c') diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c index 5000586cb98d..0a806924b906 100644 --- a/drivers/spi/spi-s3c64xx.c +++ b/drivers/spi/spi-s3c64xx.c @@ -39,6 +39,7 @@ #endif #define MAX_SPI_PORTS 3 +#define S3C64XX_SPI_QUIRK_POLL (1 << 0) /* Registers and bit-fields */ @@ -130,6 +131,7 @@ #define S3C64XX_SPI_TRAILCNT S3C64XX_SPI_MAX_TRAILCNT #define msecs_to_loops(t) (loops_per_jiffy / 1000 * HZ * t) +#define is_polling(x) (x->port_conf->quirks & S3C64XX_SPI_QUIRK_POLL) #define RXBUSY (1<<2) #define TXBUSY (1<<3) @@ -158,6 +160,7 @@ struct s3c64xx_spi_port_config { int fifo_lvl_mask[MAX_SPI_PORTS]; int rx_lvl_offset; int tx_st_done; + int quirks; bool high_speed; bool clk_from_cmu; }; @@ -344,8 +347,12 @@ static int s3c64xx_spi_prepare_transfer(struct spi_master *spi) { struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(spi); - /* Acquire DMA channels */ - while (!acquire_dma(sdd)) + /* + * If DMA resource was not available during + * probe, no need to continue with dma requests + * else Acquire DMA channels + */ + while (!is_polling(sdd) && !acquire_dma(sdd)) usleep_range(10000, 11000); pm_runtime_get_sync(&sdd->pdev->dev); @@ -358,9 +365,12 @@ static int s3c64xx_spi_unprepare_transfer(struct spi_master *spi) struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(spi); /* Free DMA channels */ - sdd->ops->release((enum dma_ch)sdd->rx_dma.ch, &s3c64xx_spi_dma_client); - sdd->ops->release((enum dma_ch)sdd->tx_dma.ch, &s3c64xx_spi_dma_client); - + if (!is_polling(sdd)) { + sdd->ops->release((enum dma_ch)sdd->rx_dma.ch, + &s3c64xx_spi_dma_client); + sdd->ops->release((enum dma_ch)sdd->tx_dma.ch, + &s3c64xx_spi_dma_client); + } pm_runtime_put(&sdd->pdev->dev); return 0; @@ -464,8 +474,10 @@ static int s3c64xx_spi_unprepare_transfer(struct spi_master *spi) struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(spi); /* Free DMA channels */ - dma_release_channel(sdd->rx_dma.ch); - dma_release_channel(sdd->tx_dma.ch); + if (!is_polling(sdd)) { + dma_release_channel(sdd->rx_dma.ch); + dma_release_channel(sdd->tx_dma.ch); + } pm_runtime_put(&sdd->pdev->dev); return 0; @@ -566,6 +578,30 @@ static inline void enable_cs(struct s3c64xx_spi_driver_data *sdd, cs = spi->controller_data; gpio_set_value(cs->line, spi->mode & SPI_CS_HIGH ? 1 : 0); + + /* Start the signals */ + writel(0, sdd->regs + S3C64XX_SPI_SLAVE_SEL); +} + +static u32 wait_for_timeout(struct s3c64xx_spi_driver_data *sdd, + int timeout_ms) +{ + void __iomem *regs = sdd->regs; + unsigned long val = 1; + u32 status; + + /* max fifo depth available */ + u32 max_fifo = (FIFO_LVL_MASK(sdd) >> 1) + 1; + + if (timeout_ms) + val = msecs_to_loops(timeout_ms); + + do { + status = readl(regs + S3C64XX_SPI_STATUS); + } while (RX_FIFO_LVL(status, sdd) < max_fifo && --val); + + /* return the actual received data length */ + return RX_FIFO_LVL(status, sdd); } static int wait_for_xfer(struct s3c64xx_spi_driver_data *sdd, @@ -590,20 +626,19 @@ static int wait_for_xfer(struct s3c64xx_spi_driver_data *sdd, } while (RX_FIFO_LVL(status, sdd) < xfer->len && --val); } - if (!val) - return -EIO; - if (dma_mode) { u32 status; /* + * If the previous xfer was completed within timeout, then + * proceed further else return -EIO. * DmaTx returns after simply writing data in the FIFO, * w/o waiting for real transmission on the bus to finish. * DmaRx returns only after Dma read data from FIFO which * needs bus transmission to finish, so we don't worry if * Xfer involved Rx(with or without Tx). */ - if (xfer->rx_buf == NULL) { + if (val && !xfer->rx_buf) { val = msecs_to_loops(10); status = readl(regs + S3C64XX_SPI_STATUS); while ((TX_FIFO_LVL(status, sdd) @@ -613,30 +648,53 @@ static int wait_for_xfer(struct s3c64xx_spi_driver_data *sdd, status = readl(regs + S3C64XX_SPI_STATUS); } - if (!val) - return -EIO; } + + /* If timed out while checking rx/tx status return error */ + if (!val) + return -EIO; } else { + int loops; + u32 cpy_len; + u8 *buf; + /* If it was only Tx */ - if (xfer->rx_buf == NULL) { + if (!xfer->rx_buf) { sdd->state &= ~TXBUSY; return 0; } - switch (sdd->cur_bpw) { - case 32: - ioread32_rep(regs + S3C64XX_SPI_RX_DATA, - xfer->rx_buf, xfer->len / 4); - break; - case 16: - ioread16_rep(regs + S3C64XX_SPI_RX_DATA, - xfer->rx_buf, xfer->len / 2); - break; - default: - ioread8_rep(regs + S3C64XX_SPI_RX_DATA, - xfer->rx_buf, xfer->len); - break; - } + /* + * If the receive length is bigger than the controller fifo + * size, calculate the loops and read the fifo as many times. + * loops = length / max fifo size (calculated by using the + * fifo mask). + * For any size less than the fifo size the below code is + * executed atleast once. + */ + loops = xfer->len / ((FIFO_LVL_MASK(sdd) >> 1) + 1); + buf = xfer->rx_buf; + do { + /* wait for data to be received in the fifo */ + cpy_len = wait_for_timeout(sdd, (loops ? ms : 0)); + + switch (sdd->cur_bpw) { + case 32: + ioread32_rep(regs + S3C64XX_SPI_RX_DATA, + buf, cpy_len / 4); + break; + case 16: + ioread16_rep(regs + S3C64XX_SPI_RX_DATA, + buf, cpy_len / 2); + break; + default: + ioread8_rep(regs + S3C64XX_SPI_RX_DATA, + buf, cpy_len); + break; + } + + buf = buf + cpy_len; + } while (loops--); sdd->state &= ~RXBUSY; } @@ -652,6 +710,9 @@ static inline void disable_cs(struct s3c64xx_spi_driver_data *sdd, sdd->tgl_spi = NULL; gpio_set_value(cs->line, spi->mode & SPI_CS_HIGH ? 0 : 1); + + /* Quiese the signals */ + writel(S3C64XX_SPI_SLAVE_SIG_INACT, sdd->regs + S3C64XX_SPI_SLAVE_SEL); } static void s3c64xx_spi_config(struct s3c64xx_spi_driver_data *sdd) @@ -733,7 +794,7 @@ static int s3c64xx_spi_map_mssg(struct s3c64xx_spi_driver_data *sdd, struct device *dev = &sdd->pdev->dev; struct spi_transfer *xfer; - if (msg->is_dma_mapped) + if (is_polling(sdd) || msg->is_dma_mapped) return 0; /* First mark all xfer unmapped */ @@ -782,7 +843,7 @@ static void s3c64xx_spi_unmap_mssg(struct s3c64xx_spi_driver_data *sdd, struct device *dev = &sdd->pdev->dev; struct spi_transfer *xfer; - if (msg->is_dma_mapped) + if (is_polling(sdd) || msg->is_dma_mapped) return; list_for_each_entry(xfer, &msg->transfers, transfer_list) { @@ -861,8 +922,9 @@ static int s3c64xx_spi_transfer_one_message(struct spi_master *master, /* Polling method for xfers not bigger than FIFO capacity */ use_dma = 0; - if (sdd->rx_dma.ch && sdd->tx_dma.ch && - (xfer->len > ((FIFO_LVL_MASK(sdd) >> 1) + 1))) + if (!is_polling(sdd) && + (sdd->rx_dma.ch && sdd->tx_dma.ch && + (xfer->len > ((FIFO_LVL_MASK(sdd) >> 1) + 1)))) use_dma = 1; spin_lock_irqsave(&sdd->lock, flags); @@ -876,17 +938,10 @@ static int s3c64xx_spi_transfer_one_message(struct spi_master *master, /* Slave Select */ enable_cs(sdd, spi); - /* Start the signals */ - writel(0, sdd->regs + S3C64XX_SPI_SLAVE_SEL); - spin_unlock_irqrestore(&sdd->lock, flags); status = wait_for_xfer(sdd, xfer, use_dma); - /* Quiese the signals */ - writel(S3C64XX_SPI_SLAVE_SIG_INACT, - sdd->regs + S3C64XX_SPI_SLAVE_SEL); - if (status) { dev_err(&spi->dev, "I/O Error: rx-%d tx-%d res:rx-%c tx-%c len-%d\n", xfer->rx_buf ? 1 : 0, xfer->tx_buf ? 1 : 0, @@ -1287,19 +1342,19 @@ static int s3c64xx_spi_probe(struct platform_device *pdev) if (!sdd->pdev->dev.of_node) { res = platform_get_resource(pdev, IORESOURCE_DMA, 0); if (!res) { - dev_err(&pdev->dev, "Unable to get SPI tx dma " - "resource\n"); - return -ENXIO; - } - sdd->tx_dma.dmach = res->start; + dev_warn(&pdev->dev, "Unable to get SPI tx dma " + "resource. Switching to poll mode\n"); + sdd->port_conf->quirks = S3C64XX_SPI_QUIRK_POLL; + } else + sdd->tx_dma.dmach = res->start; res = platform_get_resource(pdev, IORESOURCE_DMA, 1); if (!res) { - dev_err(&pdev->dev, "Unable to get SPI rx dma " - "resource\n"); - return -ENXIO; - } - sdd->rx_dma.dmach = res->start; + dev_warn(&pdev->dev, "Unable to get SPI rx dma " + "resource. Switching to poll mode\n"); + sdd->port_conf->quirks = S3C64XX_SPI_QUIRK_POLL; + } else + sdd->rx_dma.dmach = res->start; } sdd->tx_dma.direction = DMA_MEM_TO_DEV; -- cgit v1.2.3 From 796170733e50405e3039eacdf5cfb2f08f3eb9ba Mon Sep 17 00:00:00 2001 From: Mark Brown Date: Wed, 19 Jun 2013 19:12:39 +0100 Subject: spi/s3c64xx: Make wait_for_timeout() function name less generic Signed-off-by: Mark Brown --- drivers/spi/spi-s3c64xx.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'drivers/spi/spi-s3c64xx.c') diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c index 0a806924b906..70b221355400 100644 --- a/drivers/spi/spi-s3c64xx.c +++ b/drivers/spi/spi-s3c64xx.c @@ -583,7 +583,7 @@ static inline void enable_cs(struct s3c64xx_spi_driver_data *sdd, writel(0, sdd->regs + S3C64XX_SPI_SLAVE_SEL); } -static u32 wait_for_timeout(struct s3c64xx_spi_driver_data *sdd, +static u32 s3c64xx_spi_wait_for_timeout(struct s3c64xx_spi_driver_data *sdd, int timeout_ms) { void __iomem *regs = sdd->regs; @@ -676,7 +676,8 @@ static int wait_for_xfer(struct s3c64xx_spi_driver_data *sdd, buf = xfer->rx_buf; do { /* wait for data to be received in the fifo */ - cpy_len = wait_for_timeout(sdd, (loops ? ms : 0)); + cpy_len = s3c64xx_spi_wait_for_timeout(sdd, + (loops ? ms : 0)); switch (sdd->cur_bpw) { case 32: -- cgit v1.2.3 From 3146beec21b64f4551fcf0ac148381d54dc41b1b Mon Sep 17 00:00:00 2001 From: Girish K S Date: Fri, 21 Jun 2013 11:26:12 +0530 Subject: spi: s3c64xx: Added provision for dedicated cs pin The existing driver supports gpio based /cs signal. For controller's that have one device per controller, the slave device's /cs signal might be internally controlled by the chip select bit of slave select register. They are not externally asserted/deasserted using gpio pin. This patch adds support for controllers with dedicated /cs pin. if "cs-gpio" property doesnt exist in a spi dts node, the controller would treat the /cs pin as dedicated. Signed-off-by: Girish K S Signed-off-by: Mark Brown --- drivers/spi/spi-s3c64xx.c | 34 ++++++++++++++++++++++++++-------- 1 file changed, 26 insertions(+), 8 deletions(-) (limited to 'drivers/spi/spi-s3c64xx.c') diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c index 70b221355400..067f442de2d4 100644 --- a/drivers/spi/spi-s3c64xx.c +++ b/drivers/spi/spi-s3c64xx.c @@ -208,6 +208,7 @@ struct s3c64xx_spi_driver_data { struct s3c64xx_spi_port_config *port_conf; unsigned int port_id; unsigned long gpios[4]; + bool cs_gpio; }; static void flush_fifo(struct s3c64xx_spi_driver_data *sdd) @@ -570,14 +571,16 @@ static inline void enable_cs(struct s3c64xx_spi_driver_data *sdd, if (sdd->tgl_spi != spi) { /* if last mssg on diff device */ /* Deselect the last toggled device */ cs = sdd->tgl_spi->controller_data; - gpio_set_value(cs->line, - spi->mode & SPI_CS_HIGH ? 0 : 1); + if (sdd->cs_gpio) + gpio_set_value(cs->line, + spi->mode & SPI_CS_HIGH ? 0 : 1); } sdd->tgl_spi = NULL; } cs = spi->controller_data; - gpio_set_value(cs->line, spi->mode & SPI_CS_HIGH ? 1 : 0); + if (sdd->cs_gpio) + gpio_set_value(cs->line, spi->mode & SPI_CS_HIGH ? 1 : 0); /* Start the signals */ writel(0, sdd->regs + S3C64XX_SPI_SLAVE_SEL); @@ -710,7 +713,8 @@ static inline void disable_cs(struct s3c64xx_spi_driver_data *sdd, if (sdd->tgl_spi == spi) sdd->tgl_spi = NULL; - gpio_set_value(cs->line, spi->mode & SPI_CS_HIGH ? 0 : 1); + if (sdd->cs_gpio) + gpio_set_value(cs->line, spi->mode & SPI_CS_HIGH ? 0 : 1); /* Quiese the signals */ writel(S3C64XX_SPI_SLAVE_SIG_INACT, sdd->regs + S3C64XX_SPI_SLAVE_SEL); @@ -998,8 +1002,10 @@ static struct s3c64xx_spi_csinfo *s3c64xx_get_slave_ctrldata( { struct s3c64xx_spi_csinfo *cs; struct device_node *slave_np, *data_np = NULL; + struct s3c64xx_spi_driver_data *sdd; u32 fb_delay = 0; + sdd = spi_master_get_devdata(spi->master); slave_np = spi->dev.of_node; if (!slave_np) { dev_err(&spi->dev, "device node not found\n"); @@ -1019,7 +1025,10 @@ static struct s3c64xx_spi_csinfo *s3c64xx_get_slave_ctrldata( return ERR_PTR(-ENOMEM); } - cs->line = of_get_named_gpio(data_np, "cs-gpio", 0); + /* The CS line is asserted/deasserted by the gpio pin */ + if (sdd->cs_gpio) + cs->line = of_get_named_gpio(data_np, "cs-gpio", 0); + if (!gpio_is_valid(cs->line)) { dev_err(&spi->dev, "chip select gpio is not specified or invalid\n"); kfree(cs); @@ -1059,7 +1068,8 @@ static int s3c64xx_spi_setup(struct spi_device *spi) return -ENODEV; } - if (!spi_get_ctldata(spi)) { + /* Request gpio only if cs line is asserted by gpio pins */ + if (sdd->cs_gpio) { err = gpio_request_one(cs->line, GPIOF_OUT_INIT_HIGH, dev_name(&spi->dev)); if (err) { @@ -1068,9 +1078,11 @@ static int s3c64xx_spi_setup(struct spi_device *spi) cs->line, err); goto err_gpio_req; } - spi_set_ctldata(spi, cs); } + if (!spi_get_ctldata(spi)) + spi_set_ctldata(spi, cs); + sci = sdd->cntrlr_info; spin_lock_irqsave(&sdd->lock, flags); @@ -1148,8 +1160,10 @@ err_gpio_req: static void s3c64xx_spi_cleanup(struct spi_device *spi) { struct s3c64xx_spi_csinfo *cs = spi_get_ctldata(spi); + struct s3c64xx_spi_driver_data *sdd; - if (cs) { + sdd = spi_master_get_devdata(spi->master); + if (cs && sdd->cs_gpio) { gpio_free(cs->line); if (spi->dev.of_node) kfree(cs); @@ -1326,7 +1340,11 @@ static int s3c64xx_spi_probe(struct platform_device *pdev) sdd->cntrlr_info = sci; sdd->pdev = pdev; sdd->sfr_start = mem_res->start; + sdd->cs_gpio = true; if (pdev->dev.of_node) { + if (!of_find_property(pdev->dev.of_node, "cs-gpio", NULL)) + sdd->cs_gpio = false; + ret = of_alias_get_id(pdev->dev.of_node, "spi"); if (ret < 0) { dev_err(&pdev->dev, "failed to get alias id, errno %d\n", -- cgit v1.2.3 From bff82038ca3e2976ad0b51d32c7a8c9ed31065f7 Mon Sep 17 00:00:00 2001 From: Girish K S Date: Fri, 21 Jun 2013 11:26:13 +0530 Subject: spi: s3c64xx: Added support for exynos5440 spi This patch adds support for the exynos5440 spi controller. The integration of the spi IP in exynos5440 is different from other SoC's. The I/O pins are no more configured via gpio, they have dedicated pins. Signed-off-by: Girish K S Signed-off-by: Mark Brown --- drivers/spi/spi-s3c64xx.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'drivers/spi/spi-s3c64xx.c') diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c index 067f442de2d4..d170cc0d81a0 100644 --- a/drivers/spi/spi-s3c64xx.c +++ b/drivers/spi/spi-s3c64xx.c @@ -1609,6 +1609,15 @@ static struct s3c64xx_spi_port_config exynos4_spi_port_config = { .clk_from_cmu = true, }; +static struct s3c64xx_spi_port_config exynos5440_spi_port_config = { + .fifo_lvl_mask = { 0x1ff }, + .rx_lvl_offset = 15, + .tx_st_done = 25, + .high_speed = true, + .clk_from_cmu = true, + .quirks = S3C64XX_SPI_QUIRK_POLL, +}; + static struct platform_device_id s3c64xx_spi_driver_ids[] = { { .name = "s3c2443-spi", @@ -1637,6 +1646,9 @@ static const struct of_device_id s3c64xx_spi_dt_match[] = { { .compatible = "samsung,exynos4210-spi", .data = (void *)&exynos4_spi_port_config, }, + { .compatible = "samsung,exynos5440-spi", + .data = (void *)&exynos5440_spi_port_config, + }, { }, }; MODULE_DEVICE_TABLE(of, s3c64xx_spi_dt_match); -- cgit v1.2.3 From cd469106c3aa2303d928c20a35cac5d669f816f7 Mon Sep 17 00:00:00 2001 From: Mark Brown Date: Wed, 26 Jun 2013 16:09:48 +0100 Subject: spi/s3c64xx: Rely on the compiler eliminating the OF ID table This should work with modern compilers, isn't that much of an issue if it goes wrong and it ensures that the DT-only hardware variants don't leave unreferenced parameters structures lying around. Signed-off-by: Mark Brown --- drivers/spi/spi-s3c64xx.c | 2 -- 1 file changed, 2 deletions(-) (limited to 'drivers/spi/spi-s3c64xx.c') diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c index d170cc0d81a0..ecc0f06d71ef 100644 --- a/drivers/spi/spi-s3c64xx.c +++ b/drivers/spi/spi-s3c64xx.c @@ -1641,7 +1641,6 @@ static struct platform_device_id s3c64xx_spi_driver_ids[] = { { }, }; -#ifdef CONFIG_OF static const struct of_device_id s3c64xx_spi_dt_match[] = { { .compatible = "samsung,exynos4210-spi", .data = (void *)&exynos4_spi_port_config, @@ -1652,7 +1651,6 @@ static const struct of_device_id s3c64xx_spi_dt_match[] = { { }, }; MODULE_DEVICE_TABLE(of, s3c64xx_spi_dt_match); -#endif /* CONFIG_OF */ static struct platform_driver s3c64xx_spi_driver = { .driver = { -- cgit v1.2.3