Skip to content

Commit

Permalink
spi: tegra: use dmaengine based dma driver
Browse files Browse the repository at this point in the history 
Use the dmaengine based Tegra APB DMA driver for
data transfer between SPI FIFO and memory in
place of legacy Tegra APB DMA.

The new driver is selected if legacy driver is not
selected and new DMA driver is enabled through config
file.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
  • Loading branch information
Laxman Dewangan authored and Mark Brown committed Jul 10, 2012
1 parent d8e328b commit 619ac8d
Show file tree
Hide file tree
Showing 2 changed files with 85 additions and 6 deletions.
2 changes: 1 addition & 1 deletion drivers/spi/Kconfig
View file
Original file line number Diff line number Diff line change
Expand Up @@ -357,7 +357,7 @@ config SPI_STMP3XXX

config SPI_TEGRA
tristate "Nvidia Tegra SPI controller"
depends on ARCH_TEGRA && TEGRA_SYSTEM_DMA
depends on ARCH_TEGRA && (TEGRA_SYSTEM_DMA || TEGRA20_APB_DMA)
help
SPI driver for NVidia Tegra SoCs

Expand Down
89 changes: 84 additions & 5 deletions drivers/spi/spi-tegra.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -30,6 +30,7 @@
#include <linux/delay.h>

#include <linux/spi/spi.h>
#include <linux/dmaengine.h>

#include <mach/dma.h>

Expand Down Expand Up @@ -162,12 +163,23 @@ struct spi_tegra_data {
* require transfers to be 4 byte aligned we need a bounce buffer
* for the generic case.
*/
int dma_req_len;
#if defined(CONFIG_TEGRA_SYSTEM_DMA)
struct tegra_dma_req rx_dma_req;
struct tegra_dma_channel *rx_dma;
#else
struct dma_chan *rx_dma;
struct dma_slave_config sconfig;
struct dma_async_tx_descriptor *rx_dma_desc;
dma_cookie_t rx_cookie;
#endif
u32 *rx_bb;
dma_addr_t rx_bb_phys;
};

#if !defined(CONFIG_TEGRA_SYSTEM_DMA)
static void tegra_spi_rx_dma_complete(void *args);
#endif

static inline unsigned long spi_tegra_readl(struct spi_tegra_data *tspi,
unsigned long reg)
Expand All @@ -190,10 +202,24 @@ static void spi_tegra_go(struct spi_tegra_data *tspi)

val = spi_tegra_readl(tspi, SLINK_DMA_CTL);
val &= ~SLINK_DMA_BLOCK_SIZE(~0) & ~SLINK_DMA_EN;
val |= SLINK_DMA_BLOCK_SIZE(tspi->rx_dma_req.size / 4 - 1);
val |= SLINK_DMA_BLOCK_SIZE(tspi->dma_req_len / 4 - 1);
spi_tegra_writel(tspi, val, SLINK_DMA_CTL);

#if defined(CONFIG_TEGRA_SYSTEM_DMA)
tspi->rx_dma_req.size = tspi->dma_req_len;
tegra_dma_enqueue_req(tspi->rx_dma, &tspi->rx_dma_req);
#else
tspi->rx_dma_desc = dmaengine_prep_slave_single(tspi->rx_dma,
tspi->rx_bb_phys, tspi->dma_req_len,
DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT);
if (!tspi->rx_dma_desc) {
dev_err(&tspi->pdev->dev, "dmaengine slave prep failed\n");
return;
}
tspi->rx_dma_desc->callback = tegra_spi_rx_dma_complete;
tspi->rx_dma_desc->callback_param = tspi;
tspi->rx_cookie = dmaengine_submit(tspi->rx_dma_desc);
dma_async_issue_pending(tspi->rx_dma);
#endif

val |= SLINK_DMA_EN;
spi_tegra_writel(tspi, val, SLINK_DMA_CTL);
Expand Down Expand Up @@ -221,7 +247,7 @@ static unsigned spi_tegra_fill_tx_fifo(struct spi_tegra_data *tspi,
spi_tegra_writel(tspi, val, SLINK_TX_FIFO);
}

tspi->rx_dma_req.size = len / tspi->cur_bytes_per_word * 4;
tspi->dma_req_len = len / tspi->cur_bytes_per_word * 4;

return len;
}
Expand Down Expand Up @@ -318,9 +344,8 @@ static void spi_tegra_start_message(struct spi_device *spi,
spi_tegra_start_transfer(spi, t);
}

static void tegra_spi_rx_dma_complete(struct tegra_dma_req *req)
static void handle_spi_rx_dma_complete(struct spi_tegra_data *tspi)
{
struct spi_tegra_data *tspi = req->dev;
unsigned long flags;
struct spi_message *m;
struct spi_device *spi;
Expand Down Expand Up @@ -380,6 +405,19 @@ static void tegra_spi_rx_dma_complete(struct tegra_dma_req *req)

spin_unlock_irqrestore(&tspi->lock, flags);
}
#if defined(CONFIG_TEGRA_SYSTEM_DMA)
static void tegra_spi_rx_dma_complete(struct tegra_dma_req *req)
{
struct spi_tegra_data *tspi = req->dev;
handle_spi_rx_dma_complete(tspi);
}
#else
static void tegra_spi_rx_dma_complete(void *args)
{
struct spi_tegra_data *tspi = args;
handle_spi_rx_dma_complete(tspi);
}
#endif

static int spi_tegra_setup(struct spi_device *spi)
{
Expand Down Expand Up @@ -471,6 +509,9 @@ static int __devinit spi_tegra_probe(struct platform_device *pdev)
struct spi_tegra_data *tspi;
struct resource *r;
int ret;
#if !defined(CONFIG_TEGRA_SYSTEM_DMA)
dma_cap_mask_t mask;
#endif

master = spi_alloc_master(&pdev->dev, sizeof *tspi);
if (master == NULL) {
Expand Down Expand Up @@ -522,12 +563,24 @@ static int __devinit spi_tegra_probe(struct platform_device *pdev)

INIT_LIST_HEAD(&tspi->queue);

#if defined(CONFIG_TEGRA_SYSTEM_DMA)
tspi->rx_dma = tegra_dma_allocate_channel(TEGRA_DMA_MODE_ONESHOT);
if (!tspi->rx_dma) {
dev_err(&pdev->dev, "can not allocate rx dma channel\n");
ret = -ENODEV;
goto err3;
}
#else
dma_cap_zero(mask);
dma_cap_set(DMA_SLAVE, mask);
tspi->rx_dma = dma_request_channel(mask, NULL, NULL);
if (!tspi->rx_dma) {
dev_err(&pdev->dev, "can not allocate rx dma channel\n");
ret = -ENODEV;
goto err3;
}

#endif

tspi->rx_bb = dma_alloc_coherent(&pdev->dev, sizeof(u32) * BB_LEN,
&tspi->rx_bb_phys, GFP_KERNEL);
Expand All @@ -537,6 +590,7 @@ static int __devinit spi_tegra_probe(struct platform_device *pdev)
goto err4;
}

#if defined(CONFIG_TEGRA_SYSTEM_DMA)
tspi->rx_dma_req.complete = tegra_spi_rx_dma_complete;
tspi->rx_dma_req.to_memory = 1;
tspi->rx_dma_req.dest_addr = tspi->rx_bb_phys;
Expand All @@ -546,6 +600,23 @@ static int __devinit spi_tegra_probe(struct platform_device *pdev)
tspi->rx_dma_req.source_wrap = 4;
tspi->rx_dma_req.req_sel = spi_tegra_req_sels[pdev->id];
tspi->rx_dma_req.dev = tspi;
#else
/* Dmaengine Dma slave config */
tspi->sconfig.src_addr = tspi->phys + SLINK_RX_FIFO;
tspi->sconfig.dst_addr = tspi->phys + SLINK_RX_FIFO;
tspi->sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
tspi->sconfig.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
tspi->sconfig.slave_id = spi_tegra_req_sels[pdev->id];
tspi->sconfig.src_maxburst = 1;
tspi->sconfig.dst_maxburst = 1;
ret = dmaengine_device_control(tspi->rx_dma,
DMA_SLAVE_CONFIG, (unsigned long) &tspi->sconfig);
if (ret < 0) {
dev_err(&pdev->dev, "can not do slave configure for dma %d\n",
ret);
goto err4;
}
#endif

master->dev.of_node = pdev->dev.of_node;
ret = spi_register_master(master);
Expand All @@ -559,7 +630,11 @@ static int __devinit spi_tegra_probe(struct platform_device *pdev)
dma_free_coherent(&pdev->dev, sizeof(u32) * BB_LEN,
tspi->rx_bb, tspi->rx_bb_phys);
err4:
#if defined(CONFIG_TEGRA_SYSTEM_DMA)
tegra_dma_free_channel(tspi->rx_dma);
#else
dma_release_channel(tspi->rx_dma);
#endif
err3:
clk_put(tspi->clk);
err2:
Expand All @@ -581,7 +656,11 @@ static int __devexit spi_tegra_remove(struct platform_device *pdev)
tspi = spi_master_get_devdata(master);

spi_unregister_master(master);
#if defined(CONFIG_TEGRA_SYSTEM_DMA)
tegra_dma_free_channel(tspi->rx_dma);
#else
dma_release_channel(tspi->rx_dma);
#endif

dma_free_coherent(&pdev->dev, sizeof(u32) * BB_LEN,
tspi->rx_bb, tspi->rx_bb_phys);
Expand Down

0 comments on commit 619ac8d

Please sign in to comment.