summaryrefslogtreecommitdiffstats
path: root/drivers/spi/altera_spi.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/spi/altera_spi.c')
-rw-r--r--drivers/spi/altera_spi.c27
1 files changed, 26 insertions, 1 deletions
diff --git a/drivers/spi/altera_spi.c b/drivers/spi/altera_spi.c
index 4fd82fb905..6cf9942d9d 100644
--- a/drivers/spi/altera_spi.c
+++ b/drivers/spi/altera_spi.c
@@ -25,6 +25,9 @@
#include <io.h>
#include <asm/spi.h>
#include <asm/nios2-io.h>
+#include <clock.h>
+
+static void altera_spi_cs_inactive(struct spi_device *spi);
static int altera_spi_setup(struct spi_device *spi)
{
@@ -49,6 +52,8 @@ static int altera_spi_setup(struct spi_device *spi)
return -1;
}
+ altera_spi_cs_inactive(spi);
+
dev_dbg(master->dev, " mode 0x%08x, bits_per_word: %d, speed: %d\n",
spi->mode, spi->bits_per_word, altera_spi->speed);
@@ -167,19 +172,38 @@ static int altera_spi_transfer(struct spi_device *spi, struct spi_message *mesg)
struct altera_spi *altera_spi = container_of(spi->master, struct altera_spi, master);
struct nios_spi *nios_spi = altera_spi->regs;
struct spi_transfer *t;
+ unsigned int cs_change;
+ const int nsecs = 50;
altera_spi_cs_active(spi);
+ cs_change = 0;
+
mesg->actual_length = 0;
list_for_each_entry(t, &mesg->transfers, transfer_list) {
+
+ if (cs_change) {
+ ndelay(nsecs);
+ altera_spi_cs_inactive(spi);
+ ndelay(nsecs);
+ altera_spi_cs_active(spi);
+ }
+
+ cs_change = t->cs_change;
+
mesg->actual_length += altera_spi_do_xfer(spi, t);
+
+ if (cs_change) {
+ altera_spi_cs_active(spi);
+ }
}
/* Wait the end of any pending transfer */
while ((readl(&nios_spi->status) & NIOS_SPI_TMT) == 0);
- altera_spi_cs_inactive(spi);
+ if (!cs_change)
+ altera_spi_cs_inactive(spi);
return 0;
}
@@ -199,6 +223,7 @@ static int altera_spi_probe(struct device_d *dev)
master->setup = altera_spi_setup;
master->transfer = altera_spi_transfer;
master->num_chipselect = pdata->num_chipselect;
+ master->bus_num = pdata->bus_num;
altera_spi->regs = dev_request_mem_region(dev, 0);
altera_spi->databits = pdata->databits;