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path: root/drivers/spi/spi.c
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Diffstat (limited to 'drivers/spi/spi.c')
-rw-r--r--drivers/spi/spi.c26
1 files changed, 20 insertions, 6 deletions
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 838783c3fed0..656dd3e3220c 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -697,10 +697,15 @@ static void spi_set_cs(struct spi_device *spi, bool enable)
if (spi->mode & SPI_CS_HIGH)
enable = !enable;
- if (gpio_is_valid(spi->cs_gpio))
+ if (gpio_is_valid(spi->cs_gpio)) {
gpio_set_value(spi->cs_gpio, !enable);
- else if (spi->master->set_cs)
+ /* Some SPI masters need both GPIO CS & slave_select */
+ if ((spi->master->flags & SPI_MASTER_GPIO_SS) &&
+ spi->master->set_cs)
+ spi->master->set_cs(spi, !enable);
+ } else if (spi->master->set_cs) {
spi->master->set_cs(spi, !enable);
+ }
}
#ifdef CONFIG_HAS_DMA
@@ -720,6 +725,7 @@ static int spi_map_buf(struct spi_master *master, struct device *dev,
int desc_len;
int sgs;
struct page *vm_page;
+ struct scatterlist *sg;
void *sg_buf;
size_t min;
int i, ret;
@@ -738,6 +744,7 @@ static int spi_map_buf(struct spi_master *master, struct device *dev,
if (ret != 0)
return ret;
+ sg = &sgt->sgl[0];
for (i = 0; i < sgs; i++) {
if (vmalloced_buf || kmap_buf) {
@@ -751,16 +758,17 @@ static int spi_map_buf(struct spi_master *master, struct device *dev,
sg_free_table(sgt);
return -ENOMEM;
}
- sg_set_page(&sgt->sgl[i], vm_page,
+ sg_set_page(sg, vm_page,
min, offset_in_page(buf));
} else {
min = min_t(size_t, len, desc_len);
sg_buf = buf;
- sg_set_buf(&sgt->sgl[i], sg_buf, min);
+ sg_set_buf(sg, sg_buf, min);
}
buf += min;
len -= min;
+ sg = sg_next(sg);
}
ret = dma_map_sg(dev, sgt->sgl, sgt->nents, dir);
@@ -1034,8 +1042,14 @@ static int spi_transfer_one_message(struct spi_master *master,
if (msg->status != -EINPROGRESS)
goto out;
- if (xfer->delay_usecs)
- udelay(xfer->delay_usecs);
+ if (xfer->delay_usecs) {
+ u16 us = xfer->delay_usecs;
+
+ if (us <= 10)
+ udelay(us);
+ else
+ usleep_range(us, us + DIV_ROUND_UP(us, 10));
+ }
if (xfer->cs_change) {
if (list_is_last(&xfer->transfer_list,