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spi: imx: add support for all SPI word width for DMA 

DMA transfer for SPI was limited to up to 8 bits word size until now.
Sync in SPI burst size and DMA bus width is necessary to correctly
support 16 and 32 BPW.

Signed-off-by: Anton Bondarenko <anton.bondarenko.sama@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Anton Bondarenko 2016-02-24 09:20:29 +01:00 committed by Mark Brown
parent 882f329f31
commit f12ae171c7
1 changed files with 91 additions and 27 deletions
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118
drivers/spi/spi-imx.c
View File

@ -89,11 +89,15 @@ struct spi_imx_data {
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 *);
void (*rx)(struct spi_imx_data *);
@ -199,15 +203,35 @@ 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 && transfer->len >= spi_imx->wml &&
(transfer->len % spi_imx->wml) == 0)
return true;
return false;
if (!master->dma_rx)
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
@ -775,11 +799,63 @@ 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;
@ -808,6 +884,13 @@ static int spi_imx_setupxfer(struct spi_device *spi,
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;
@ -829,10 +912,8 @@ static void spi_imx_sdma_exit(struct spi_imx_data *spi_imx)
}
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 */
@ -850,16 +931,6 @@ 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)) {
@ -869,15 +940,7 @@ 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);
@ -1164,6 +1227,7 @@ 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) {
@ -1204,7 +1268,7 @@ 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;