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authorJan Kiszka <jan.kiszka@siemens.com>2017-07-08 10:41:18 +0200
committerMark Brown <broonie@kernel.org>2017-07-17 12:09:52 +0100
commit676a4e3bab445d53fca4756865e2c0e2a87c38d6 (patch)
treed0852607196169bbd483ec63564fd8e73cea496a /drivers/spi/spi-pxa2xx.c
parent5771a8c08880cdca3bfb4a3fc6d309d6bba20877 (diff)
downloadlinux-676a4e3bab445d53fca4756865e2c0e2a87c38d6.tar.gz
spi: pxa2xx: Only claim CS GPIOs when the slave device is created
Avoid hogging chip select GPIOs just because they are listed for the master. They might be mulitplexed and, if no slave device is attached, used for different purposes. Moreover, this strategy avoids having to allocate a cs_gpiods structure. Tested on the IOT2000 where the second SPI bus is connected to an Arduino-compatible connector and multiplexed between SPI, GPIO and PWM usage. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/spi/spi-pxa2xx.c')
-rw-r--r--drivers/spi/spi-pxa2xx.c59
1 files changed, 21 insertions, 38 deletions
diff --git a/drivers/spi/spi-pxa2xx.c b/drivers/spi/spi-pxa2xx.c
index 38d053682892..be991266a6ce 100644
--- a/drivers/spi/spi-pxa2xx.c
+++ b/drivers/spi/spi-pxa2xx.c
@@ -1213,21 +1213,33 @@ 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);
+ struct device *pdev = &drv_data->pdev->dev;
+ struct gpio_desc *gpiod;
int err = 0;
+ int count;
if (chip == NULL)
return 0;
- if (drv_data->cs_gpiods) {
- struct gpio_desc *gpiod;
+ count = gpiod_count(pdev, "cs");
+ if (count > 0) {
+ if (spi->chip_select >= count)
+ return -EINVAL;
+
+ gpiod = gpiod_get_index(pdev, "cs", spi->chip_select,
+ GPIOD_OUT_HIGH);
+ if (IS_ERR(gpiod)) {
+ /* Means use native chip select */
+ if (PTR_ERR(gpiod) == -ENOENT)
+ return 0;
- 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 PTR_ERR(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;
}
@@ -1415,8 +1427,7 @@ static void cleanup(struct spi_device *spi)
if (!chip)
return;
- if (drv_data->ssp_type != CE4100_SSP && !drv_data->cs_gpiods &&
- gpio_is_valid(chip->gpio_cs))
+ if (drv_data->ssp_type != CE4100_SSP && gpio_is_valid(chip->gpio_cs))
gpio_free(chip->gpio_cs);
kfree(chip);
@@ -1752,38 +1763,10 @@ 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;
-
+ if (count > 0)
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);