From 881a0b993e9f065cbb3673c94c395fa1de24bdcc Mon Sep 17 00:00:00 2001 From: Trent Piepho Date: Tue, 31 Oct 2017 12:49:04 -0700 Subject: [PATCH] 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 CC: Shawn Guo CC: Sascha Hauer CC: Fabio Estevam CC: Oleksij Rempel Signed-off-by: Trent Piepho Signed-off-by: Mark Brown --- drivers/spi/spi-imx.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c index 5ddd32b..70dcc8e 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; -- 2.7.4