diff options
Diffstat (limited to 'drivers/spi/spi-bcm2835.c')
| -rw-r--r-- | drivers/spi/spi-bcm2835.c | 38 |
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); |