diff options
author | Mark Brown <broonie@kernel.org> | 2016-03-11 14:28:22 +0700 |
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committer | Mark Brown <broonie@kernel.org> | 2016-03-11 14:28:22 +0700 |
commit | ce7fb74f546cdd5a83fe9393263364f9d38cc96f (patch) | |
tree | b231a7f461cfaeed08e60c14a9a2369d9e65d5e4 /drivers/spi | |
parent | a75481ab4a5276770e0fb7e137a4f170b90fc48b (diff) | |
parent | 6b6192c04bf48ba5bec72287c2e5e9ae28217f6b (diff) | |
download | linux-ce7fb74f546cdd5a83fe9393263364f9d38cc96f.tar.bz2 |
Merge remote-tracking branch 'spi/topic/imx' into spi-next
Diffstat (limited to 'drivers/spi')
-rw-r--r-- | drivers/spi/spi-imx.c | 341 |
1 files changed, 183 insertions, 158 deletions
diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c index c688efa95e29..e7a19be87c38 100644 --- a/drivers/spi/spi-imx.c +++ b/drivers/spi/spi-imx.c @@ -56,7 +56,6 @@ /* The maximum bytes that a sdma BD can transfer.*/ #define MAX_SDMA_BD_BYTES (1 << 15) -#define IMX_DMA_TIMEOUT (msecs_to_jiffies(3000)) struct spi_imx_config { unsigned int speed_hz; unsigned int bpw; @@ -86,12 +85,18 @@ struct spi_imx_devtype_data { struct spi_imx_data { struct spi_bitbang bitbang; + struct device *dev; struct completion xfer_done; void __iomem *base; + unsigned long base_phys; + struct clk *clk_per; struct clk *clk_ipg; unsigned long spi_clk; + unsigned int spi_bus_clk; + + unsigned int bytes_per_word; unsigned int count; void (*tx)(struct spi_imx_data *); @@ -101,8 +106,6 @@ struct spi_imx_data { unsigned int txfifo; /* number of words pushed in tx FIFO */ /* DMA */ - unsigned int dma_is_inited; - unsigned int dma_finished; bool usedma; u32 wml; struct completion dma_rx_completion; @@ -199,15 +202,35 @@ static unsigned int spi_imx_clkdiv_2(unsigned int fin, return 7; } +static int spi_imx_bytes_per_word(const int bpw) +{ + return DIV_ROUND_UP(bpw, BITS_PER_BYTE); +} + static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi, struct spi_transfer *transfer) { struct spi_imx_data *spi_imx = spi_master_get_devdata(master); + unsigned int bpw = transfer->bits_per_word; + + if (!master->dma_rx) + return false; - if (spi_imx->dma_is_inited && transfer->len >= spi_imx->wml && - (transfer->len % spi_imx->wml) == 0) - return true; - return false; + if (!bpw) + bpw = spi->bits_per_word; + + bpw = spi_imx_bytes_per_word(bpw); + + if (bpw != 1 && bpw != 2 && bpw != 4) + return false; + + if (transfer->len < spi_imx->wml * bpw) + return false; + + if (transfer->len % (spi_imx->wml * bpw)) + return false; + + return true; } #define MX51_ECSPI_CTRL 0x08 @@ -232,16 +255,13 @@ static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi, #define MX51_ECSPI_INT_RREN (1 << 3) #define MX51_ECSPI_DMA 0x14 -#define MX51_ECSPI_DMA_TX_WML_OFFSET 0 -#define MX51_ECSPI_DMA_TX_WML_MASK 0x3F -#define MX51_ECSPI_DMA_RX_WML_OFFSET 16 -#define MX51_ECSPI_DMA_RX_WML_MASK (0x3F << 16) -#define MX51_ECSPI_DMA_RXT_WML_OFFSET 24 -#define MX51_ECSPI_DMA_RXT_WML_MASK (0x3F << 24) +#define MX51_ECSPI_DMA_TX_WML(wml) ((wml) & 0x3f) +#define MX51_ECSPI_DMA_RX_WML(wml) (((wml) & 0x3f) << 16) +#define MX51_ECSPI_DMA_RXT_WML(wml) (((wml) & 0x3f) << 24) -#define MX51_ECSPI_DMA_TEDEN_OFFSET 7 -#define MX51_ECSPI_DMA_RXDEN_OFFSET 23 -#define MX51_ECSPI_DMA_RXTDEN_OFFSET 31 +#define MX51_ECSPI_DMA_TEDEN (1 << 7) +#define MX51_ECSPI_DMA_RXDEN (1 << 23) +#define MX51_ECSPI_DMA_RXTDEN (1 << 31) #define MX51_ECSPI_STAT 0x18 #define MX51_ECSPI_STAT_RR (1 << 3) @@ -250,14 +270,15 @@ static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi, #define MX51_ECSPI_TESTREG_LBC BIT(31) /* MX51 eCSPI */ -static unsigned int mx51_ecspi_clkdiv(unsigned int fin, unsigned int fspi, - unsigned int *fres) +static unsigned int mx51_ecspi_clkdiv(struct spi_imx_data *spi_imx, + unsigned int fspi, unsigned int *fres) { /* * there are two 4-bit dividers, the pre-divider divides by * $pre, the post-divider by 2^$post */ unsigned int pre, post; + unsigned int fin = spi_imx->spi_clk; if (unlikely(fspi > fin)) return 0; @@ -270,14 +291,14 @@ static unsigned int mx51_ecspi_clkdiv(unsigned int fin, unsigned int fspi, post = max(4U, post) - 4; if (unlikely(post > 0xf)) { - pr_err("%s: cannot set clock freq: %u (base freq: %u)\n", - __func__, fspi, fin); + dev_err(spi_imx->dev, "cannot set clock freq: %u (base freq: %u)\n", + fspi, fin); return 0xff; } pre = DIV_ROUND_UP(fin, fspi << post) - 1; - pr_debug("%s: fin: %u, fspi: %u, post: %u, pre: %u\n", + dev_dbg(spi_imx->dev, "%s: fin: %u, fspi: %u, post: %u, pre: %u\n", __func__, fin, fspi, post, pre); /* Resulting frequency for the SCLK line. */ @@ -302,22 +323,17 @@ static void __maybe_unused mx51_ecspi_intctrl(struct spi_imx_data *spi_imx, int static void __maybe_unused mx51_ecspi_trigger(struct spi_imx_data *spi_imx) { - u32 reg = readl(spi_imx->base + MX51_ECSPI_CTRL); + u32 reg; - if (!spi_imx->usedma) - reg |= MX51_ECSPI_CTRL_XCH; - else if (!spi_imx->dma_finished) - reg |= MX51_ECSPI_CTRL_SMC; - else - reg &= ~MX51_ECSPI_CTRL_SMC; + reg = readl(spi_imx->base + MX51_ECSPI_CTRL); + reg |= MX51_ECSPI_CTRL_XCH; writel(reg, spi_imx->base + MX51_ECSPI_CTRL); } static int __maybe_unused mx51_ecspi_config(struct spi_imx_data *spi_imx, struct spi_imx_config *config) { - u32 ctrl = MX51_ECSPI_CTRL_ENABLE, cfg = 0, dma = 0; - u32 tx_wml_cfg, rx_wml_cfg, rxt_wml_cfg; + u32 ctrl = MX51_ECSPI_CTRL_ENABLE, cfg = 0; u32 clk = config->speed_hz, delay, reg; /* @@ -330,7 +346,8 @@ static int __maybe_unused mx51_ecspi_config(struct spi_imx_data *spi_imx, ctrl |= MX51_ECSPI_CTRL_MODE_MASK; /* set clock speed */ - ctrl |= mx51_ecspi_clkdiv(spi_imx->spi_clk, config->speed_hz, &clk); + ctrl |= mx51_ecspi_clkdiv(spi_imx, config->speed_hz, &clk); + spi_imx->spi_bus_clk = clk; /* set chip select to use */ ctrl |= MX51_ECSPI_CTRL_CS(config->cs); @@ -341,20 +358,16 @@ static int __maybe_unused mx51_ecspi_config(struct spi_imx_data *spi_imx, if (config->mode & SPI_CPHA) cfg |= MX51_ECSPI_CONFIG_SCLKPHA(config->cs); - else - cfg &= ~MX51_ECSPI_CONFIG_SCLKPHA(config->cs); if (config->mode & SPI_CPOL) { cfg |= MX51_ECSPI_CONFIG_SCLKPOL(config->cs); cfg |= MX51_ECSPI_CONFIG_SCLKCTL(config->cs); - } else { - cfg &= ~MX51_ECSPI_CONFIG_SCLKPOL(config->cs); - cfg &= ~MX51_ECSPI_CONFIG_SCLKCTL(config->cs); } if (config->mode & SPI_CS_HIGH) cfg |= MX51_ECSPI_CONFIG_SSBPOL(config->cs); - else - cfg &= ~MX51_ECSPI_CONFIG_SSBPOL(config->cs); + + if (spi_imx->usedma) + ctrl |= MX51_ECSPI_CTRL_SMC; /* CTRL register always go first to bring out controller from reset */ writel(ctrl, spi_imx->base + MX51_ECSPI_CTRL); @@ -389,22 +402,12 @@ static int __maybe_unused mx51_ecspi_config(struct spi_imx_data *spi_imx, * Configure the DMA register: setup the watermark * and enable DMA request. */ - if (spi_imx->dma_is_inited) { - dma = readl(spi_imx->base + MX51_ECSPI_DMA); - - rx_wml_cfg = spi_imx->wml << MX51_ECSPI_DMA_RX_WML_OFFSET; - tx_wml_cfg = spi_imx->wml << MX51_ECSPI_DMA_TX_WML_OFFSET; - rxt_wml_cfg = spi_imx->wml << MX51_ECSPI_DMA_RXT_WML_OFFSET; - dma = (dma & ~MX51_ECSPI_DMA_TX_WML_MASK - & ~MX51_ECSPI_DMA_RX_WML_MASK - & ~MX51_ECSPI_DMA_RXT_WML_MASK) - | rx_wml_cfg | tx_wml_cfg | rxt_wml_cfg - |(1 << MX51_ECSPI_DMA_TEDEN_OFFSET) - |(1 << MX51_ECSPI_DMA_RXDEN_OFFSET) - |(1 << MX51_ECSPI_DMA_RXTDEN_OFFSET); - - writel(dma, spi_imx->base + MX51_ECSPI_DMA); - } + + writel(MX51_ECSPI_DMA_RX_WML(spi_imx->wml) | + MX51_ECSPI_DMA_TX_WML(spi_imx->wml) | + MX51_ECSPI_DMA_RXT_WML(spi_imx->wml) | + MX51_ECSPI_DMA_TEDEN | MX51_ECSPI_DMA_RXDEN | + MX51_ECSPI_DMA_RXTDEN, spi_imx->base + MX51_ECSPI_DMA); return 0; } @@ -784,11 +787,63 @@ static irqreturn_t spi_imx_isr(int irq, void *dev_id) return IRQ_HANDLED; } +static int spi_imx_dma_configure(struct spi_master *master, + int bytes_per_word) +{ + int ret; + enum dma_slave_buswidth buswidth; + struct dma_slave_config rx = {}, tx = {}; + struct spi_imx_data *spi_imx = spi_master_get_devdata(master); + + if (bytes_per_word == spi_imx->bytes_per_word) + /* Same as last time */ + return 0; + + switch (bytes_per_word) { + case 4: + buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES; + break; + case 2: + buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES; + break; + case 1: + buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE; + break; + default: + return -EINVAL; + } + + tx.direction = DMA_MEM_TO_DEV; + tx.dst_addr = spi_imx->base_phys + MXC_CSPITXDATA; + tx.dst_addr_width = buswidth; + tx.dst_maxburst = spi_imx->wml; + ret = dmaengine_slave_config(master->dma_tx, &tx); + if (ret) { + dev_err(spi_imx->dev, "TX dma configuration failed with %d\n", ret); + return ret; + } + + rx.direction = DMA_DEV_TO_MEM; + rx.src_addr = spi_imx->base_phys + MXC_CSPIRXDATA; + rx.src_addr_width = buswidth; + rx.src_maxburst = spi_imx->wml; + ret = dmaengine_slave_config(master->dma_rx, &rx); + if (ret) { + dev_err(spi_imx->dev, "RX dma configuration failed with %d\n", ret); + return ret; + } + + spi_imx->bytes_per_word = bytes_per_word; + + return 0; +} + static int spi_imx_setupxfer(struct spi_device *spi, struct spi_transfer *t) { struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master); struct spi_imx_config config; + int ret; config.bpw = t ? t->bits_per_word : spi->bits_per_word; config.speed_hz = t ? t->speed_hz : spi->max_speed_hz; @@ -812,6 +867,18 @@ static int spi_imx_setupxfer(struct spi_device *spi, spi_imx->tx = spi_imx_buf_tx_u32; } + if (spi_imx_can_dma(spi_imx->bitbang.master, spi, t)) + spi_imx->usedma = 1; + else + spi_imx->usedma = 0; + + if (spi_imx->usedma) { + ret = spi_imx_dma_configure(spi->master, + spi_imx_bytes_per_word(config.bpw)); + if (ret) + return ret; + } + spi_imx->devtype_data->config(spi_imx, &config); return 0; @@ -830,15 +897,11 @@ static void spi_imx_sdma_exit(struct spi_imx_data *spi_imx) dma_release_channel(master->dma_tx); master->dma_tx = NULL; } - - spi_imx->dma_is_inited = 0; } static int spi_imx_sdma_init(struct device *dev, struct spi_imx_data *spi_imx, - struct spi_master *master, - const struct resource *res) + struct spi_master *master) { - struct dma_slave_config slave_config = {}; int ret; /* use pio mode for i.mx6dl chip TKT238285 */ @@ -856,16 +919,6 @@ static int spi_imx_sdma_init(struct device *dev, struct spi_imx_data *spi_imx, goto err; } - slave_config.direction = DMA_MEM_TO_DEV; - slave_config.dst_addr = res->start + MXC_CSPITXDATA; - slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; - slave_config.dst_maxburst = spi_imx->wml; - ret = dmaengine_slave_config(master->dma_tx, &slave_config); - if (ret) { - dev_err(dev, "error in TX dma configuration.\n"); - goto err; - } - /* Prepare for RX : */ master->dma_rx = dma_request_slave_channel_reason(dev, "rx"); if (IS_ERR(master->dma_rx)) { @@ -875,15 +928,7 @@ static int spi_imx_sdma_init(struct device *dev, struct spi_imx_data *spi_imx, goto err; } - slave_config.direction = DMA_DEV_TO_MEM; - slave_config.src_addr = res->start + MXC_CSPIRXDATA; - slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; - slave_config.src_maxburst = spi_imx->wml; - ret = dmaengine_slave_config(master->dma_rx, &slave_config); - if (ret) { - dev_err(dev, "error in RX dma configuration.\n"); - goto err; - } + spi_imx_dma_configure(master, 1); init_completion(&spi_imx->dma_rx_completion); init_completion(&spi_imx->dma_tx_completion); @@ -891,7 +936,6 @@ static int spi_imx_sdma_init(struct device *dev, struct spi_imx_data *spi_imx, master->max_dma_len = MAX_SDMA_BD_BYTES; spi_imx->bitbang.master->flags = SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX; - spi_imx->dma_is_inited = 1; return 0; err: @@ -913,95 +957,81 @@ static void spi_imx_dma_tx_callback(void *cookie) complete(&spi_imx->dma_tx_completion); } +static int spi_imx_calculate_timeout(struct spi_imx_data *spi_imx, int size) +{ + unsigned long timeout = 0; + + /* Time with actual data transfer and CS change delay related to HW */ + timeout = (8 + 4) * size / spi_imx->spi_bus_clk; + + /* Add extra second for scheduler related activities */ + timeout += 1; + + /* Double calculated timeout */ + return msecs_to_jiffies(2 * timeout * MSEC_PER_SEC); +} + static int spi_imx_dma_transfer(struct spi_imx_data *spi_imx, struct spi_transfer *transfer) { - struct dma_async_tx_descriptor *desc_tx = NULL, *desc_rx = NULL; - int ret; + struct dma_async_tx_descriptor *desc_tx, *desc_rx; + unsigned long transfer_timeout; unsigned long timeout; struct spi_master *master = spi_imx->bitbang.master; struct sg_table *tx = &transfer->tx_sg, *rx = &transfer->rx_sg; - if (tx) { - desc_tx = dmaengine_prep_slave_sg(master->dma_tx, - tx->sgl, tx->nents, DMA_MEM_TO_DEV, - DMA_PREP_INTERRUPT | DMA_CTRL_ACK); - if (!desc_tx) - goto tx_nodma; - - desc_tx->callback = spi_imx_dma_tx_callback; - desc_tx->callback_param = (void *)spi_imx; - dmaengine_submit(desc_tx); - } + /* + * The TX DMA setup starts the transfer, so make sure RX is configured + * before TX. + */ + desc_rx = dmaengine_prep_slave_sg(master->dma_rx, + rx->sgl, rx->nents, DMA_DEV_TO_MEM, + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + if (!desc_rx) + return -EINVAL; - if (rx) { - desc_rx = dmaengine_prep_slave_sg(master->dma_rx, - rx->sgl, rx->nents, DMA_DEV_TO_MEM, - DMA_PREP_INTERRUPT | DMA_CTRL_ACK); - if (!desc_rx) - goto rx_nodma; + desc_rx->callback = spi_imx_dma_rx_callback; + desc_rx->callback_param = (void *)spi_imx; + dmaengine_submit(desc_rx); + reinit_completion(&spi_imx->dma_rx_completion); + dma_async_issue_pending(master->dma_rx); - desc_rx->callback = spi_imx_dma_rx_callback; - desc_rx->callback_param = (void *)spi_imx; - dmaengine_submit(desc_rx); + desc_tx = dmaengine_prep_slave_sg(master->dma_tx, + tx->sgl, tx->nents, DMA_MEM_TO_DEV, + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + if (!desc_tx) { + dmaengine_terminate_all(master->dma_tx); + return -EINVAL; } - reinit_completion(&spi_imx->dma_rx_completion); + desc_tx->callback = spi_imx_dma_tx_callback; + desc_tx->callback_param = (void *)spi_imx; + dmaengine_submit(desc_tx); reinit_completion(&spi_imx->dma_tx_completion); - - /* Trigger the cspi module. */ - spi_imx->dma_finished = 0; - - /* - * Set these order to avoid potential RX overflow. The overflow may - * happen if we enable SPI HW before starting RX DMA due to rescheduling - * for another task and/or interrupt. - * So RX DMA enabled first to make sure data would be read out from FIFO - * ASAP. TX DMA enabled next to start filling TX FIFO with new data. - * And finaly SPI HW enabled to start actual data transfer. - */ - dma_async_issue_pending(master->dma_rx); dma_async_issue_pending(master->dma_tx); - spi_imx->devtype_data->trigger(spi_imx); + + transfer_timeout = spi_imx_calculate_timeout(spi_imx, transfer->len); /* Wait SDMA to finish the data transfer.*/ timeout = wait_for_completion_timeout(&spi_imx->dma_tx_completion, - IMX_DMA_TIMEOUT); + transfer_timeout); if (!timeout) { - pr_warn("%s %s: I/O Error in DMA TX\n", - dev_driver_string(&master->dev), - dev_name(&master->dev)); + dev_err(spi_imx->dev, "I/O Error in DMA TX\n"); dmaengine_terminate_all(master->dma_tx); dmaengine_terminate_all(master->dma_rx); - } else { - timeout = wait_for_completion_timeout( - &spi_imx->dma_rx_completion, IMX_DMA_TIMEOUT); - if (!timeout) { - pr_warn("%s %s: I/O Error in DMA RX\n", - dev_driver_string(&master->dev), - dev_name(&master->dev)); - spi_imx->devtype_data->reset(spi_imx); - dmaengine_terminate_all(master->dma_rx); - } + return -ETIMEDOUT; } - spi_imx->dma_finished = 1; - spi_imx->devtype_data->trigger(spi_imx); - - if (!timeout) - ret = -ETIMEDOUT; - else - ret = transfer->len; - - return ret; + timeout = wait_for_completion_timeout(&spi_imx->dma_rx_completion, + transfer_timeout); + if (!timeout) { + dev_err(&master->dev, "I/O Error in DMA RX\n"); + spi_imx->devtype_data->reset(spi_imx); + dmaengine_terminate_all(master->dma_rx); + return -ETIMEDOUT; + } -rx_nodma: - dmaengine_terminate_all(master->dma_tx); -tx_nodma: - pr_warn_once("%s %s: DMA not available, falling back to PIO\n", - dev_driver_string(&master->dev), - dev_name(&master->dev)); - return -EAGAIN; + return transfer->len; } static int spi_imx_pio_transfer(struct spi_device *spi, @@ -1028,19 +1058,12 @@ static int spi_imx_pio_transfer(struct spi_device *spi, static int spi_imx_transfer(struct spi_device *spi, struct spi_transfer *transfer) { - int ret; struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master); - if (spi_imx->bitbang.master->can_dma && - spi_imx_can_dma(spi_imx->bitbang.master, spi, transfer)) { - spi_imx->usedma = true; - ret = spi_imx_dma_transfer(spi_imx, transfer); - if (ret != -EAGAIN) - return ret; - } - spi_imx->usedma = false; - - return spi_imx_pio_transfer(spi, transfer); + if (spi_imx->usedma) + return spi_imx_dma_transfer(spi_imx, transfer); + else + return spi_imx_pio_transfer(spi, transfer); } static int spi_imx_setup(struct spi_device *spi) @@ -1130,6 +1153,7 @@ static int spi_imx_probe(struct platform_device *pdev) spi_imx = spi_master_get_devdata(master); spi_imx->bitbang.master = master; + spi_imx->dev = &pdev->dev; spi_imx->devtype_data = of_id ? of_id->data : (struct spi_imx_devtype_data *)pdev->id_entry->driver_data; @@ -1170,6 +1194,7 @@ static int spi_imx_probe(struct platform_device *pdev) ret = PTR_ERR(spi_imx->base); goto out_master_put; } + spi_imx->base_phys = res->start; irq = platform_get_irq(pdev, 0); if (irq < 0) { @@ -1210,7 +1235,7 @@ static int spi_imx_probe(struct platform_device *pdev) * other chips. */ if (is_imx51_ecspi(spi_imx)) { - ret = spi_imx_sdma_init(&pdev->dev, spi_imx, master, res); + ret = spi_imx_sdma_init(&pdev->dev, spi_imx, master); if (ret == -EPROBE_DEFER) goto out_clk_put; |