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authorMika Westerberg <mika.westerberg@linux.intel.com>2016-09-26 14:19:50 +0200
committerMark Brown <broonie@kernel.org>2016-09-26 18:11:14 +0200
commit99f499cd650405bbe6a9b5386d4b11ee81514fb7 (patch)
tree48882d1cafee7da91e34946f6666104d21b0ff4a /drivers/spi/spi-pxa2xx.c
parentspi: pxa2xx: Default thresholds to PXA configuration (diff)
downloadlinux-99f499cd650405bbe6a9b5386d4b11ee81514fb7.tar.xz
linux-99f499cd650405bbe6a9b5386d4b11ee81514fb7.zip
spi: pxa2xx: Add support for GPIO descriptor chip selects
The driver uses custom chip_info coming from platform data for chip selects implemented as GPIOs. If the system lacks board files setting up the platform data, it is not possible to use GPIOs as chip selects. This adds support for GPIO descriptors so that regardless of the underlying firmware interface (DT, ACPI or platform data) the driver can request GPIOs used as chip selects and configure them accordingly. The custom chip_info GPIO support is still left there to make sure the existing systems keep working as expected. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/spi/spi-pxa2xx.c')
-rw-r--r--drivers/spi/spi-pxa2xx.c57
1 files changed, 54 insertions, 3 deletions
diff --git a/drivers/spi/spi-pxa2xx.c b/drivers/spi/spi-pxa2xx.c
index cab39b06bc89..5e2ed7d34487 100644
--- a/drivers/spi/spi-pxa2xx.c
+++ b/drivers/spi/spi-pxa2xx.c
@@ -1194,9 +1194,26 @@ static int pxa2xx_spi_unprepare_transfer(struct spi_master *master)
static int setup_cs(struct spi_device *spi, struct chip_data *chip,
struct pxa2xx_spi_chip *chip_info)
{
+ struct driver_data *drv_data = spi_master_get_devdata(spi->master);
int err = 0;
- if (chip == NULL || chip_info == NULL)
+ if (chip == NULL)
+ return 0;
+
+ if (drv_data->cs_gpiods) {
+ struct gpio_desc *gpiod;
+
+ gpiod = drv_data->cs_gpiods[spi->chip_select];
+ if (gpiod) {
+ chip->gpio_cs = desc_to_gpio(gpiod);
+ chip->gpio_cs_inverted = spi->mode & SPI_CS_HIGH;
+ gpiod_set_value(gpiod, chip->gpio_cs_inverted);
+ }
+
+ return 0;
+ }
+
+ if (chip_info == NULL)
return 0;
/* NOTE: setup() can be called multiple times, possibly with
@@ -1379,7 +1396,8 @@ static void cleanup(struct spi_device *spi)
if (!chip)
return;
- if (drv_data->ssp_type != CE4100_SSP && gpio_is_valid(chip->gpio_cs))
+ if (drv_data->ssp_type != CE4100_SSP && !drv_data->cs_gpiods &&
+ gpio_is_valid(chip->gpio_cs))
gpio_free(chip->gpio_cs);
kfree(chip);
@@ -1557,7 +1575,7 @@ static int pxa2xx_spi_probe(struct platform_device *pdev)
struct driver_data *drv_data;
struct ssp_device *ssp;
const struct lpss_config *config;
- int status;
+ int status, count;
u32 tmp;
platform_info = dev_get_platdata(dev);
@@ -1701,6 +1719,39 @@ static int pxa2xx_spi_probe(struct platform_device *pdev)
}
master->num_chipselect = platform_info->num_chipselect;
+ count = gpiod_count(&pdev->dev, "cs");
+ if (count > 0) {
+ int i;
+
+ master->num_chipselect = max_t(int, count,
+ master->num_chipselect);
+
+ drv_data->cs_gpiods = devm_kcalloc(&pdev->dev,
+ master->num_chipselect, sizeof(struct gpio_desc *),
+ GFP_KERNEL);
+ if (!drv_data->cs_gpiods) {
+ status = -ENOMEM;
+ goto out_error_clock_enabled;
+ }
+
+ for (i = 0; i < master->num_chipselect; i++) {
+ struct gpio_desc *gpiod;
+
+ gpiod = devm_gpiod_get_index(dev, "cs", i,
+ GPIOD_OUT_HIGH);
+ if (IS_ERR(gpiod)) {
+ /* Means use native chip select */
+ if (PTR_ERR(gpiod) == -ENOENT)
+ continue;
+
+ status = (int)PTR_ERR(gpiod);
+ goto out_error_clock_enabled;
+ } else {
+ drv_data->cs_gpiods[i] = gpiod;
+ }
+ }
+ }
+
tasklet_init(&drv_data->pump_transfers, pump_transfers,
(unsigned long)drv_data);