aboutsummaryrefslogtreecommitdiffstats
path: root/drivers
diff options
context:
space:
mode:
authorTrent Piepho <tpiepho@impinj.com>2017-10-31 12:49:04 -0700
committerMark Brown <broonie@kernel.org>2017-11-10 21:28:09 +0000
commit881a0b993e9f065cbb3673c94c395fa1de24bdcc (patch)
treef1b4c669c780d8ec548f1df1415a1912d254c726 /drivers
parent974488e4ce1ed0b39f2c711c13f523c5912128a1 (diff)
spi: imx: GPIO based chip selects should not be required
The driver will fail to load if no gpio chip selects are specified, this patch changes this so that it no longer fails. It's possible to use all native chip selects, in which case there is no reason to have a gpio chip select array. This is what happens if the *optional* device tree property "cs-gpios" is omitted. The spi core already checks for the absence of gpio chip selects in the master and assigns any slaves the gpio_cs value of -ENOENT. Also have the driver respect the standard SPI device tree property "num-cs" to allow setting the number of chip selects without using cs-gpios. CC: Mark Brown <broonie@kernel.org> CC: Shawn Guo <shawnguo@kernel.org> CC: Sascha Hauer <kernel@pengutronix.de> CC: Fabio Estevam <fabio.estevam@nxp.com> CC: Oleksij Rempel <o.rempel@pengutronix.de> Signed-off-by: Trent Piepho <tpiepho@impinj.com> Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/spi/spi-imx.c18
1 files changed, 10 insertions, 8 deletions
diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c
index 5ddd32ba2521..70dcc8ee1f6b 100644
--- a/drivers/spi/spi-imx.c
+++ b/drivers/spi/spi-imx.c
@@ -1523,6 +1523,7 @@ static int spi_imx_probe(struct platform_device *pdev)
spi_imx->devtype_data = devtype_data;
+ /* Get number of chip selects, either platform data or OF */
if (mxc_platform_info) {
master->num_chipselect = mxc_platform_info->num_chipselect;
master->cs_gpios = devm_kzalloc(&master->dev,
@@ -1532,7 +1533,13 @@ static int spi_imx_probe(struct platform_device *pdev)
for (i = 0; i < master->num_chipselect; i++)
master->cs_gpios[i] = mxc_platform_info->chipselect[i];
- }
+ } else {
+ u32 num_cs;
+
+ if (!of_property_read_u32(np, "num-cs", &num_cs))
+ master->num_chipselect = num_cs;
+ /* If not preset, default value of 1 is used */
+ }
spi_imx->bitbang.chipselect = spi_imx_chipselect;
spi_imx->bitbang.setup_transfer = spi_imx_setupxfer;
@@ -1614,13 +1621,8 @@ static int spi_imx_probe(struct platform_device *pdev)
master->dev.of_node = pdev->dev.of_node;
- if (!spi_imx->slave_mode) {
- if (!master->cs_gpios) {
- dev_err(&pdev->dev, "No CS GPIOs available\n");
- ret = -EINVAL;
- goto out_clk_put;
- }
-
+ /* Request GPIO CS lines, if any */
+ if (!spi_imx->slave_mode && master->cs_gpios) {
for (i = 0; i < master->num_chipselect; i++) {
if (!gpio_is_valid(master->cs_gpios[i]))
continue;

Privacy Policy