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path: root/drivers/spi/spi-imx.c
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Diffstat (limited to 'drivers/spi/spi-imx.c')
-rw-r--r--drivers/spi/spi-imx.c116
1 files changed, 69 insertions, 47 deletions
diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c
index 0e5723ab4..c688efa95 100644
--- a/drivers/spi/spi-imx.c
+++ b/drivers/spi/spi-imx.c
@@ -104,9 +104,7 @@ struct spi_imx_data {
unsigned int dma_is_inited;
unsigned int dma_finished;
bool usedma;
- u32 rx_wml;
- u32 tx_wml;
- u32 rxt_wml;
+ u32 wml;
struct completion dma_rx_completion;
struct completion dma_tx_completion;
@@ -124,9 +122,14 @@ static inline int is_imx35_cspi(struct spi_imx_data *d)
return d->devtype_data->devtype == IMX35_CSPI;
}
+static inline int is_imx51_ecspi(struct spi_imx_data *d)
+{
+ return d->devtype_data->devtype == IMX51_ECSPI;
+}
+
static inline unsigned spi_imx_get_fifosize(struct spi_imx_data *d)
{
- return (d->devtype_data->devtype == IMX51_ECSPI) ? 64 : 8;
+ return is_imx51_ecspi(d) ? 64 : 8;
}
#define MXC_SPI_BUF_RX(type) \
@@ -201,9 +204,8 @@ static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi,
{
struct spi_imx_data *spi_imx = spi_master_get_devdata(master);
- if (spi_imx->dma_is_inited
- && transfer->len > spi_imx->rx_wml * sizeof(u32)
- && transfer->len > spi_imx->tx_wml * sizeof(u32))
+ if (spi_imx->dma_is_inited && transfer->len >= spi_imx->wml &&
+ (transfer->len % spi_imx->wml) == 0)
return true;
return false;
}
@@ -244,6 +246,9 @@ static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi,
#define MX51_ECSPI_STAT 0x18
#define MX51_ECSPI_STAT_RR (1 << 3)
+#define MX51_ECSPI_TESTREG 0x20
+#define MX51_ECSPI_TESTREG_LBC BIT(31)
+
/* MX51 eCSPI */
static unsigned int mx51_ecspi_clkdiv(unsigned int fin, unsigned int fspi,
unsigned int *fres)
@@ -313,7 +318,7 @@ static int __maybe_unused mx51_ecspi_config(struct spi_imx_data *spi_imx,
{
u32 ctrl = MX51_ECSPI_CTRL_ENABLE, cfg = 0, dma = 0;
u32 tx_wml_cfg, rx_wml_cfg, rxt_wml_cfg;
- u32 clk = config->speed_hz, delay;
+ u32 clk = config->speed_hz, delay, reg;
/*
* The hardware seems to have a race condition when changing modes. The
@@ -351,7 +356,16 @@ static int __maybe_unused mx51_ecspi_config(struct spi_imx_data *spi_imx,
else
cfg &= ~MX51_ECSPI_CONFIG_SSBPOL(config->cs);
+ /* CTRL register always go first to bring out controller from reset */
writel(ctrl, spi_imx->base + MX51_ECSPI_CTRL);
+
+ reg = readl(spi_imx->base + MX51_ECSPI_TESTREG);
+ if (config->mode & SPI_LOOP)
+ reg |= MX51_ECSPI_TESTREG_LBC;
+ else
+ reg &= ~MX51_ECSPI_TESTREG_LBC;
+ writel(reg, spi_imx->base + MX51_ECSPI_TESTREG);
+
writel(cfg, spi_imx->base + MX51_ECSPI_CONFIG);
/*
@@ -378,10 +392,9 @@ static int __maybe_unused mx51_ecspi_config(struct spi_imx_data *spi_imx,
if (spi_imx->dma_is_inited) {
dma = readl(spi_imx->base + MX51_ECSPI_DMA);
- spi_imx->rxt_wml = spi_imx_get_fifosize(spi_imx) / 2;
- rx_wml_cfg = spi_imx->rx_wml << MX51_ECSPI_DMA_RX_WML_OFFSET;
- tx_wml_cfg = spi_imx->tx_wml << MX51_ECSPI_DMA_TX_WML_OFFSET;
- rxt_wml_cfg = spi_imx->rxt_wml << MX51_ECSPI_DMA_RXT_WML_OFFSET;
+ 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)
@@ -832,18 +845,21 @@ static int spi_imx_sdma_init(struct device *dev, struct spi_imx_data *spi_imx,
if (of_machine_is_compatible("fsl,imx6dl"))
return 0;
+ spi_imx->wml = spi_imx_get_fifosize(spi_imx) / 2;
+
/* Prepare for TX DMA: */
- master->dma_tx = dma_request_slave_channel(dev, "tx");
- if (!master->dma_tx) {
- dev_err(dev, "cannot get the TX DMA channel!\n");
- ret = -EINVAL;
+ master->dma_tx = dma_request_slave_channel_reason(dev, "tx");
+ if (IS_ERR(master->dma_tx)) {
+ ret = PTR_ERR(master->dma_tx);
+ dev_dbg(dev, "can't get the TX DMA channel, error %d!\n", ret);
+ master->dma_tx = NULL;
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_get_fifosize(spi_imx) / 2;
+ 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");
@@ -851,17 +867,18 @@ static int spi_imx_sdma_init(struct device *dev, struct spi_imx_data *spi_imx,
}
/* Prepare for RX : */
- master->dma_rx = dma_request_slave_channel(dev, "rx");
- if (!master->dma_rx) {
- dev_dbg(dev, "cannot get the DMA channel.\n");
- ret = -EINVAL;
+ master->dma_rx = dma_request_slave_channel_reason(dev, "rx");
+ if (IS_ERR(master->dma_rx)) {
+ ret = PTR_ERR(master->dma_rx);
+ dev_dbg(dev, "can't get the RX DMA channel, error %d\n", ret);
+ master->dma_rx = NULL;
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_get_fifosize(spi_imx) / 2;
+ 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");
@@ -874,8 +891,6 @@ 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->tx_wml = spi_imx_get_fifosize(spi_imx) / 2;
- spi_imx->rx_wml = spi_imx_get_fifosize(spi_imx) / 2;
spi_imx->dma_is_inited = 1;
return 0;
@@ -904,8 +919,6 @@ static int spi_imx_dma_transfer(struct spi_imx_data *spi_imx,
struct dma_async_tx_descriptor *desc_tx = NULL, *desc_rx = NULL;
int ret;
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;
@@ -914,7 +927,7 @@ static int spi_imx_dma_transfer(struct spi_imx_data *spi_imx,
tx->sgl, tx->nents, DMA_MEM_TO_DEV,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!desc_tx)
- goto no_dma;
+ goto tx_nodma;
desc_tx->callback = spi_imx_dma_tx_callback;
desc_tx->callback_param = (void *)spi_imx;
@@ -926,7 +939,7 @@ static int spi_imx_dma_transfer(struct spi_imx_data *spi_imx,
rx->sgl, rx->nents, DMA_DEV_TO_MEM,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!desc_rx)
- goto no_dma;
+ goto rx_nodma;
desc_rx->callback = spi_imx_dma_rx_callback;
desc_rx->callback_param = (void *)spi_imx;
@@ -939,17 +952,18 @@ static int spi_imx_dma_transfer(struct spi_imx_data *spi_imx,
/* 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->rxt_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);
- dma_async_issue_pending(master->dma_tx);
- dma_async_issue_pending(master->dma_rx);
/* Wait SDMA to finish the data transfer.*/
timeout = wait_for_completion_timeout(&spi_imx->dma_tx_completion,
IMX_DMA_TIMEOUT);
@@ -958,6 +972,7 @@ static int spi_imx_dma_transfer(struct spi_imx_data *spi_imx,
dev_driver_string(&master->dev),
dev_name(&master->dev));
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);
@@ -968,9 +983,6 @@ static int spi_imx_dma_transfer(struct spi_imx_data *spi_imx,
spi_imx->devtype_data->reset(spi_imx);
dmaengine_terminate_all(master->dma_rx);
}
- writel(dma |
- spi_imx->rxt_wml << MX51_ECSPI_DMA_RXT_WML_OFFSET,
- spi_imx->base + MX51_ECSPI_DMA);
}
spi_imx->dma_finished = 1;
@@ -983,7 +995,9 @@ static int spi_imx_dma_transfer(struct spi_imx_data *spi_imx,
return ret;
-no_dma:
+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));
@@ -1117,6 +1131,9 @@ static int spi_imx_probe(struct platform_device *pdev)
spi_imx = spi_master_get_devdata(master);
spi_imx->bitbang.master = master;
+ spi_imx->devtype_data = of_id ? of_id->data :
+ (struct spi_imx_devtype_data *)pdev->id_entry->driver_data;
+
for (i = 0; i < master->num_chipselect; i++) {
int cs_gpio = of_get_named_gpio(np, "cs-gpios", i);
if (!gpio_is_valid(cs_gpio) && mxc_platform_info)
@@ -1142,12 +1159,11 @@ static int spi_imx_probe(struct platform_device *pdev)
spi_imx->bitbang.master->prepare_message = spi_imx_prepare_message;
spi_imx->bitbang.master->unprepare_message = spi_imx_unprepare_message;
spi_imx->bitbang.master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
+ if (is_imx51_ecspi(spi_imx))
+ spi_imx->bitbang.master->mode_bits |= SPI_LOOP;
init_completion(&spi_imx->xfer_done);
- spi_imx->devtype_data = of_id ? of_id->data :
- (struct spi_imx_devtype_data *) pdev->id_entry->driver_data;
-
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
spi_imx->base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(spi_imx->base)) {
@@ -1193,9 +1209,15 @@ static int spi_imx_probe(struct platform_device *pdev)
* Only validated on i.mx6 now, can remove the constrain if validated on
* other chips.
*/
- if (spi_imx->devtype_data == &imx51_ecspi_devtype_data
- && spi_imx_sdma_init(&pdev->dev, spi_imx, master, res))
- dev_err(&pdev->dev, "dma setup error,use pio instead\n");
+ if (is_imx51_ecspi(spi_imx)) {
+ ret = spi_imx_sdma_init(&pdev->dev, spi_imx, master, res);
+ if (ret == -EPROBE_DEFER)
+ goto out_clk_put;
+
+ if (ret < 0)
+ dev_err(&pdev->dev, "dma setup error %d, use pio\n",
+ ret);
+ }
spi_imx->devtype_data->reset(spi_imx);
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-11-10 23:33:09 +0000