On 09/13/2018 08:44 AM, Geert Uytterhoeven wrote:
Hi David,
On Thu, Sep 13, 2018 at 2:40 AM David Lechner <david@xxxxxxxxxxxxxx> wrote:
This adds support for the SPI_CS_WORD flag to the TI DaVinci SPI
driver. This mode can be used as long as we are using the hardware
chip select and not a GPIO chip select.
Signed-off-by: David Lechner <david@xxxxxxxxxxxxxx>
---
drivers/spi/spi-davinci.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/drivers/spi/spi-davinci.c b/drivers/spi/spi-davinci.c
index d502cf504deb..8f7dcbc53c57 100644
--- a/drivers/spi/spi-davinci.c
+++ b/drivers/spi/spi-davinci.c
@@ -230,7 +230,8 @@ static void davinci_spi_chipselect(struct spi_device *spi, int value)
!(spi->mode & SPI_CS_HIGH));
} else {
if (value == BITBANG_CS_ACTIVE) {
- spidat1 |= SPIDAT1_CSHOLD_MASK;
+ if (!(spi->mode & SPI_CS_WORD))
+ spidat1 |= SPIDAT1_CSHOLD_MASK;
spidat1 &= ~(0x1 << chip_sel);
}
}
@@ -440,8 +441,12 @@ static int davinci_spi_setup(struct spi_device *spi)
return retval;
}
- if (internal_cs)
+ if (internal_cs) {
set_io_bits(dspi->base + SPIPC0, 1 << spi->chip_select);
+ } else if (spi->mode & SPI_CS_WORD) {
+ dev_err(&spi->dev, "SPI_CS_WORD can't be use with GPIO CS\n");
+ return -EINVAL;
Does the SPI core fall back to splitting the transfer in this case?
Hmm... it doesn't look like it.
I suppose it might be best to modify the SPI core to say:
if ((spi->mode & SPI_CS_WORD) && (!(ctlr->mode_bits & SPI_CS_WORD) ||
gpio_is_valid(spi->cs_gpio)) {
instead of:
if ((spi->mode & SPI_CS_WORD) && !(ctlr->mode_bits & SPI_CS_WORD)) {
Then we could drop the error above.
+ }
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
