[PATCH 4.4 51/73] spi: pxa2xx: Do not detect number of enabled chip selects on Intel SPT

Greg Kroah-Hartman
2016-05-17T01:20:21Z

From: Jarkko Nikula <jarkko.nikula@linux.intel.com>

commit 66ec246eb9982e7eb8e15e1fc55f543230310dd0 upstream.

Certain Intel Sunrisepoint PCH variants report zero chip selects in SPI
capabilities register even they have one per port. Detection in
pxa2xx_spi_probe() sets master->num_chipselect to 0 leading to -EINVAL
from spi_register_master() where chip select count is validated.

Fix this by not using SPI capabilities register on Sunrisepoint. They don't
have more than one chip select so use the default value 1 instead of
detection.

Fixes: 8b136baa5892 ("spi: pxa2xx: Detect number of enabled Intel LPSS SPI chip select signals")
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/spi/spi-pxa2xx.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/spi/spi-pxa2xx.c
+++ b/drivers/spi/spi-pxa2xx.c
@@ -111,7 +111,7 @@ static const struct lpss_config lpss_pla
.reg_general = -1,
.reg_ssp = 0x20,
.reg_cs_ctrl = 0x24,
- .reg_capabilities = 0xfc,
+ .reg_capabilities = -1,
.rx_threshold = 1,
.tx_threshold_lo = 32,
.tx_threshold_hi = 56,