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path: root/drivers/spi/spi-bcm2835.c
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Diffstat (limited to 'drivers/spi/spi-bcm2835.c')
-rw-r--r--drivers/spi/spi-bcm2835.c38
1 files changed, 29 insertions, 9 deletions
diff --git a/drivers/spi/spi-bcm2835.c b/drivers/spi/spi-bcm2835.c
index 59705ab23577..e7874a6171ec 100644
--- a/drivers/spi/spi-bcm2835.c
+++ b/drivers/spi/spi-bcm2835.c
@@ -480,7 +480,7 @@ static int bcm2835_spi_transfer_one_poll(struct spi_master *master,
struct spi_device *spi,
struct spi_transfer *tfr,
u32 cs,
- unsigned long xfer_time_us)
+ unsigned long long xfer_time_us)
{
struct bcm2835_spi *bs = spi_master_get_devdata(master);
unsigned long timeout;
@@ -531,7 +531,8 @@ static int bcm2835_spi_transfer_one(struct spi_master *master,
{
struct bcm2835_spi *bs = spi_master_get_devdata(master);
unsigned long spi_hz, clk_hz, cdiv;
- unsigned long spi_used_hz, xfer_time_us;
+ unsigned long spi_used_hz;
+ unsigned long long xfer_time_us;
u32 cs = bcm2835_rd(bs, BCM2835_SPI_CS);
/* set clock */
@@ -553,13 +554,11 @@ static int bcm2835_spi_transfer_one(struct spi_master *master,
spi_used_hz = cdiv ? (clk_hz / cdiv) : (clk_hz / 65536);
bcm2835_wr(bs, BCM2835_SPI_CLK, cdiv);
- /* handle all the modes */
+ /* handle all the 3-wire mode */
if ((spi->mode & SPI_3WIRE) && (tfr->rx_buf))
cs |= BCM2835_SPI_CS_REN;
- if (spi->mode & SPI_CPOL)
- cs |= BCM2835_SPI_CS_CPOL;
- if (spi->mode & SPI_CPHA)
- cs |= BCM2835_SPI_CS_CPHA;
+ else
+ cs &= ~BCM2835_SPI_CS_REN;
/* for gpio_cs set dummy CS so that no HW-CS get changed
* we can not run this in bcm2835_spi_set_cs, as it does
@@ -575,9 +574,10 @@ static int bcm2835_spi_transfer_one(struct spi_master *master,
bs->rx_len = tfr->len;
/* calculate the estimated time in us the transfer runs */
- xfer_time_us = tfr->len
+ xfer_time_us = (unsigned long long)tfr->len
* 9 /* clocks/byte - SPI-HW waits 1 clock after each byte */
- * 1000000 / spi_used_hz;
+ * 1000000;
+ do_div(xfer_time_us, spi_used_hz);
/* for short requests run polling*/
if (xfer_time_us <= BCM2835_SPI_POLLING_LIMIT_US)
@@ -592,6 +592,25 @@ static int bcm2835_spi_transfer_one(struct spi_master *master,
return bcm2835_spi_transfer_one_irq(master, spi, tfr, cs);
}
+static int bcm2835_spi_prepare_message(struct spi_master *master,
+ struct spi_message *msg)
+{
+ struct spi_device *spi = msg->spi;
+ struct bcm2835_spi *bs = spi_master_get_devdata(master);
+ u32 cs = bcm2835_rd(bs, BCM2835_SPI_CS);
+
+ cs &= ~(BCM2835_SPI_CS_CPOL | BCM2835_SPI_CS_CPHA);
+
+ if (spi->mode & SPI_CPOL)
+ cs |= BCM2835_SPI_CS_CPOL;
+ if (spi->mode & SPI_CPHA)
+ cs |= BCM2835_SPI_CS_CPHA;
+
+ bcm2835_wr(bs, BCM2835_SPI_CS, cs);
+
+ return 0;
+}
+
static void bcm2835_spi_handle_err(struct spi_master *master,
struct spi_message *msg)
{
@@ -739,6 +758,7 @@ static int bcm2835_spi_probe(struct platform_device *pdev)
master->set_cs = bcm2835_spi_set_cs;
master->transfer_one = bcm2835_spi_transfer_one;
master->handle_err = bcm2835_spi_handle_err;
+ master->prepare_message = bcm2835_spi_prepare_message;
master->dev.of_node = pdev->dev.of_node;
bs = spi_master_get_devdata(master);