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Subject[PATCH v2] spi/pxa2xx: fix incorrect SW mode chipselect setting for BayTrail LPSS SPI
Date
From: Chew, Chiau Ee <chiau.ee.chew@intel.com>

It was observed that after module removal followed by insertion,
the SW mode chipselect is not properly set. Thus causing transfer
failure due to incorrect CS toggling.

Signed-off-by: Chew, Chiau Ee <chiau.ee.chew@intel.com>
---
drivers/spi/spi-pxa2xx.c | 8 ++++++--
1 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/spi/spi-pxa2xx.c b/drivers/spi/spi-pxa2xx.c
index a98df7e..fe79210 100644
--- a/drivers/spi/spi-pxa2xx.c
+++ b/drivers/spi/spi-pxa2xx.c
@@ -118,6 +118,7 @@ static void lpss_ssp_setup(struct driver_data *drv_data)
*/
orig = readl(drv_data->ioaddr + offset + SPI_CS_CONTROL);

+ /* Test SPI_CS_CONTROL_SW_MODE bit enabling */
value = orig | SPI_CS_CONTROL_SW_MODE;
writel(value, drv_data->ioaddr + offset + SPI_CS_CONTROL);
value = readl(drv_data->ioaddr + offset + SPI_CS_CONTROL);
@@ -126,10 +127,13 @@ static void lpss_ssp_setup(struct driver_data *drv_data)
goto detection_done;
}

- value &= ~SPI_CS_CONTROL_SW_MODE;
+ orig = readl(drv_data->ioaddr + offset + SPI_CS_CONTROL);
+
+ /* Test SPI_CS_CONTROL_SW_MODE bit disabling */
+ value = orig & ~SPI_CS_CONTROL_SW_MODE;
writel(value, drv_data->ioaddr + offset + SPI_CS_CONTROL);
value = readl(drv_data->ioaddr + offset + SPI_CS_CONTROL);
- if (value != orig) {
+ if (value != (orig & ~SPI_CS_CONTROL_SW_MODE)) {
offset = 0x800;
goto detection_done;
}
--
1.7.4.4


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