From de5bf02cb1f61de0c65a539cd0083ac8ab07ec50 Mon Sep 17 00:00:00 2001 From: Fabio Estevam Date: Thu, 15 Nov 2012 11:23:23 +0000 Subject: spi: mxc_spi: Fix handling of chip select 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 --- drivers/spi/mxc_spi.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'drivers/spi') diff --git a/drivers/spi/mxc_spi.c b/drivers/spi/mxc_spi.c index 13bebe8..b6bad98 100644 --- a/drivers/spi/mxc_spi.c +++ b/drivers/spi/mxc_spi.c @@ -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) { -- cgit v1.1 From 3cea335c3410f71524b50263b8af0e7eb69ebbe4 Mon Sep 17 00:00:00 2001 From: Fabio Estevam Date: Thu, 15 Nov 2012 11:23:24 +0000 Subject: spi: mxc_spi: Fix spi clock glitch durant reset Measuring the spi clock line on a scope shows a 'glitch' during the reset of the spi. Fix this by toggling only the MXC_CSPICTRL_EN bit, so that the clock line becomes always stable. Signed-off-by: Fabio Estevam Acked-by: Stefano Babic --- drivers/spi/mxc_spi.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/spi') diff --git a/drivers/spi/mxc_spi.c b/drivers/spi/mxc_spi.c index b6bad98..859c43f 100644 --- a/drivers/spi/mxc_spi.c +++ b/drivers/spi/mxc_spi.c @@ -140,8 +140,8 @@ static s32 spi_cfg_mxc(struct mxc_spi_slave *mxcs, unsigned int cs, reg_ctrl = reg_read(®s->ctrl); /* Reset spi */ - reg_write(®s->ctrl, 0); - reg_write(®s->ctrl, (reg_ctrl | 0x1)); + reg_write(®s->ctrl, (reg_ctrl & ~MXC_CSPICTRL_EN)); + reg_write(®s->ctrl, (reg_ctrl | MXC_CSPICTRL_EN)); /* * The following computation is taken directly from Freescale's code. -- cgit v1.1