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spi: mxc_spi: Fix handling of chip select

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In decode_cs() function the polarity of the chip select must be taken into
account.

Also, for the case of low active chip select, the CS was activated too early.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
This commit is contained in:
Fabio Estevam 2012-11-15 11:23:23 +00:00 committed by Stefano Babic
parent 081237c1f7
commit de5bf02cb1
1 changed files with 3 additions and 2 deletions
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5
drivers/spi/mxc_spi.c
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@ -387,7 +387,7 @@ static int decode_cs(struct mxc_spi_slave *mxcs, unsigned int cs)
if (cs > 3) {
mxcs->gpio = cs >> 8;
cs &= 3;
ret = gpio_direction_output(mxcs->gpio, 0);
ret = gpio_direction_output(mxcs->gpio, !(mxcs->ss_pol));
if (ret) {
printf("mxc_spi: cannot setup gpio %d\n", mxcs->gpio);
return -EINVAL;
@ -414,6 +414,8 @@ struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
return NULL;
}
mxcs->ss_pol = (mode & SPI_CS_HIGH) ? 1 : 0;
ret = decode_cs(mxcs, cs);
if (ret < 0) {
free(mxcs);
@ -425,7 +427,6 @@ struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
mxcs->slave.bus = bus;
mxcs->slave.cs = cs;
mxcs->base = spi_bases[bus];
mxcs->ss_pol = (mode & SPI_CS_HIGH) ? 1 : 0;
ret = spi_cfg_mxc(mxcs, cs, max_hz, mode);
if (ret) {