/* 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;
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 *);
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;
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 * sizeof(u32))
- 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
#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)
#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;
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. */
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;
/*
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);
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);
* 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;
}
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;
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;
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 */
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)) {
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);
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:
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;
- u32 dma;
- int left;
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;
-
- dma = readl(spi_imx->base + MX51_ECSPI_DMA);
- dma = dma & (~MX51_ECSPI_DMA_RXT_WML_MASK);
- /* Change RX_DMA_LENGTH trigger dma fetch tail data */
- left = transfer->len % spi_imx->wml;
- if (left)
- writel(dma | (left << MX51_ECSPI_DMA_RXT_WML_OFFSET),
- spi_imx->base + MX51_ECSPI_DMA);
- /*
- * 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);
- }
- dma &= ~MX51_ECSPI_DMA_RXT_WML_MASK;
- writel(dma |
- spi_imx->wml << MX51_ECSPI_DMA_RXT_WML_OFFSET,
- spi_imx->base + MX51_ECSPI_DMA);
+ 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,
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)
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;
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) {
* 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;
projects / cascardo / linux.git / blobdiff