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authorGeert Uytterhoeven <geert+renesas@glider.be>2014-06-02 17:38:05 +0400
committerMark Brown <broonie@linaro.org>2014-06-02 18:49:32 +0400
commit9c5de2c1754c2bb3c69c4d7bf0d0edc0a61d8232 (patch)
tree7df2f1092d7a960b1445c72e05b6fef470d81394
parent32c64261c6f50a4e71ec7546f7e2f48eba91c985 (diff)
downloadlinux-9c5de2c1754c2bb3c69c4d7bf0d0edc0a61d8232.tar.xz
spi: rspi: Remove unused 16-bit DMA support
The 16-bit DMA support doesn't fit well within the SPI core DMA framework, as it needs to manage its own double-sized temporary buffers, for handling the interleaved data. Remove it, as there is no in-tree board code that sets rspi_plat_data.dma_width_16bit. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Mark Brown <broonie@linaro.org>
-rw-r--r--drivers/spi/spi-rspi.c84
-rw-r--r--include/linux/spi/rspi.h2
2 files changed, 6 insertions, 80 deletions
diff --git a/drivers/spi/spi-rspi.c b/drivers/spi/spi-rspi.c
index 57beda209599..3bd06fd9af47 100644
--- a/drivers/spi/spi-rspi.c
+++ b/drivers/spi/spi-rspi.c
@@ -201,7 +201,6 @@ struct rspi_data {
struct dma_chan *chan_tx;
struct dma_chan *chan_rx;
- unsigned dma_width_16bit:1;
unsigned dma_callbacked:1;
unsigned byte_access:1;
};
@@ -475,60 +474,17 @@ static void rspi_dma_unmap_sg(struct scatterlist *sg, struct dma_chan *chan,
dma_unmap_sg(chan->device->dev, sg, 1, dir);
}
-static void rspi_memory_to_8bit(void *buf, const void *data, unsigned len)
-{
- u16 *dst = buf;
- const u8 *src = data;
-
- while (len) {
- *dst++ = (u16)(*src++);
- len--;
- }
-}
-
-static void rspi_memory_from_8bit(void *buf, const void *data, unsigned len)
-{
- u8 *dst = buf;
- const u16 *src = data;
-
- while (len) {
- *dst++ = (u8)*src++;
- len--;
- }
-}
-
static int rspi_send_dma(struct rspi_data *rspi, struct spi_transfer *t)
{
struct scatterlist sg;
- const void *buf = NULL;
+ const void *buf = t->tx_buf;
struct dma_async_tx_descriptor *desc;
- unsigned int len;
+ unsigned int len = t->len;
int ret = 0;
- if (rspi->dma_width_16bit) {
- void *tmp;
- /*
- * If DMAC bus width is 16-bit, the driver allocates a dummy
- * buffer. And, the driver converts original data into the
- * DMAC data as the following format:
- * original data: 1st byte, 2nd byte ...
- * DMAC data: 1st byte, dummy, 2nd byte, dummy ...
- */
- len = t->len * 2;
- tmp = kmalloc(len, GFP_KERNEL);
- if (!tmp)
- return -ENOMEM;
- rspi_memory_to_8bit(tmp, t->tx_buf, t->len);
- buf = tmp;
- } else {
- len = t->len;
- buf = t->tx_buf;
- }
+ if (!rspi_dma_map_sg(&sg, buf, len, rspi->chan_tx, DMA_TO_DEVICE))
+ return -EFAULT;
- if (!rspi_dma_map_sg(&sg, buf, len, rspi->chan_tx, DMA_TO_DEVICE)) {
- ret = -EFAULT;
- goto end_nomap;
- }
desc = dmaengine_prep_slave_sg(rspi->chan_tx, &sg, 1, DMA_TO_DEVICE,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!desc) {
@@ -563,10 +519,6 @@ static int rspi_send_dma(struct rspi_data *rspi, struct spi_transfer *t)
end:
rspi_dma_unmap_sg(&sg, rspi->chan_tx, DMA_TO_DEVICE);
-end_nomap:
- if (rspi->dma_width_16bit)
- kfree(buf);
-
return ret;
}
@@ -603,28 +555,11 @@ static void qspi_receive_init(const struct rspi_data *rspi)
static int rspi_receive_dma(struct rspi_data *rspi, struct spi_transfer *t)
{
struct scatterlist sg, sg_dummy;
- void *dummy = NULL, *rx_buf = NULL;
+ void *dummy = NULL, *rx_buf = t->rx_buf;
struct dma_async_tx_descriptor *desc, *desc_dummy;
- unsigned int len;
+ unsigned int len = t->len;
int ret = 0;
- if (rspi->dma_width_16bit) {
- /*
- * If DMAC bus width is 16-bit, the driver allocates a dummy
- * buffer. And, finally the driver converts the DMAC data into
- * actual data as the following format:
- * DMAC data: 1st byte, dummy, 2nd byte, dummy ...
- * actual data: 1st byte, 2nd byte ...
- */
- len = t->len * 2;
- rx_buf = kmalloc(len, GFP_KERNEL);
- if (!rx_buf)
- return -ENOMEM;
- } else {
- len = t->len;
- rx_buf = t->rx_buf;
- }
-
/* prepare dummy transfer to generate SPI clocks */
dummy = kzalloc(len, GFP_KERNEL);
if (!dummy) {
@@ -697,11 +632,6 @@ end:
end_dummy_mapped:
rspi_dma_unmap_sg(&sg_dummy, rspi->chan_tx, DMA_TO_DEVICE);
end_nomap:
- if (rspi->dma_width_16bit) {
- if (!ret)
- rspi_memory_from_8bit(t->rx_buf, rx_buf, t->len);
- kfree(rx_buf);
- }
kfree(dummy);
return ret;
@@ -1073,8 +1003,6 @@ static int rspi_request_dma(struct rspi_data *rspi,
if (!res || !rspi_pd)
return 0; /* The driver assumes no error. */
- rspi->dma_width_16bit = rspi_pd->dma_width_16bit;
-
/* If the module receives data by DMAC, it also needs TX DMAC */
if (rspi_pd->dma_rx_id && rspi_pd->dma_tx_id) {
dma_cap_zero(mask);
diff --git a/include/linux/spi/rspi.h b/include/linux/spi/rspi.h
index a25bd6f65e7f..e546b2ceb623 100644
--- a/include/linux/spi/rspi.h
+++ b/include/linux/spi/rspi.h
@@ -25,8 +25,6 @@ struct rspi_plat_data {
unsigned int dma_tx_id;
unsigned int dma_rx_id;
- unsigned dma_width_16bit:1; /* DMAC read/write width = 16-bit */
-
u16 num_chipselect;
};