diff options
| -rw-r--r-- | Documentation/devicetree/bindings/spi/spi-gpio.txt | 29 | ||||
| -rw-r--r-- | drivers/spi/spi-gpio.c | 99 |
2 files changed, 125 insertions, 3 deletions
diff --git a/Documentation/devicetree/bindings/spi/spi-gpio.txt b/Documentation/devicetree/bindings/spi/spi-gpio.txt new file mode 100644 index 000000000000..8a824be15754 --- /dev/null +++ b/Documentation/devicetree/bindings/spi/spi-gpio.txt @@ -0,0 +1,29 @@ +SPI-GPIO devicetree bindings + +Required properties: + + - compatible: should be set to "spi-gpio" + - #address-cells: should be set to <0x1> + - ranges + - gpio-sck: GPIO spec for the SCK line to use + - gpio-miso: GPIO spec for the MISO line to use + - gpio-mosi: GPIO spec for the MOSI line to use + - cs-gpios: GPIOs to use for chipselect lines + - num-chipselects: number of chipselect lines + +Example: + + spi { + compatible = "spi-gpio"; + #address-cells = <0x1>; + ranges; + + gpio-sck = <&gpio 95 0>; + gpio-miso = <&gpio 98 0>; + gpio-mosi = <&gpio 97 0>; + cs-gpios = <&gpio 125 0>; + num-chipselects = <1>; + + /* clients */ + }; + diff --git a/drivers/spi/spi-gpio.c b/drivers/spi/spi-gpio.c index ff7263ce12c7..aed161595840 100644 --- a/drivers/spi/spi-gpio.c +++ b/drivers/spi/spi-gpio.c @@ -22,6 +22,8 @@ #include <linux/init.h> #include <linux/platform_device.h> #include <linux/gpio.h> +#include <linux/of_device.h> +#include <linux/of_gpio.h> #include <linux/spi/spi.h> #include <linux/spi/spi_bitbang.h> @@ -232,13 +234,27 @@ static void spi_gpio_chipselect(struct spi_device *spi, int is_active) static int spi_gpio_setup(struct spi_device *spi) { - unsigned int cs = (unsigned int) spi->controller_data; + unsigned int cs; int status = 0; struct spi_gpio *spi_gpio = spi_to_spi_gpio(spi); + struct device_node *np = spi->master->dev.of_node; if (spi->bits_per_word > 32) return -EINVAL; + if (np) { + /* + * In DT environments, the CS GPIOs have already been + * initialized from the "cs-gpios" property of the node. + */ + cs = spi_gpio->cs_gpios[spi->chip_select]; + } else { + /* + * ... otherwise, take it from spi->controller_data + */ + cs = (unsigned int) spi->controller_data; + } + if (!spi->controller_state) { if (cs != SPI_GPIO_NO_CHIPSELECT) { status = gpio_request(cs, dev_name(&spi->dev)); @@ -250,6 +266,7 @@ static int spi_gpio_setup(struct spi_device *spi) } if (!status) { status = spi_bitbang_setup(spi); + /* in case it was initialized from static board data */ spi_gpio->cs_gpios[spi->chip_select] = cs; } @@ -326,6 +343,55 @@ done: return value; } +#ifdef CONFIG_OF +static struct of_device_id spi_gpio_dt_ids[] = { + { .compatible = "spi-gpio" }, + {} +}; +MODULE_DEVICE_TABLE(of, spi_gpio_dt_ids); + +static int spi_gpio_probe_dt(struct platform_device *pdev) +{ + int ret; + u32 tmp; + struct spi_gpio_platform_data *pdata; + struct device_node *np = pdev->dev.of_node; + const struct of_device_id *of_id = + of_match_device(spi_gpio_dt_ids, &pdev->dev); + + if (!of_id) + return 0; + + pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL); + if (!pdata) + return -ENOMEM; + + pdata->sck = of_get_named_gpio(np, "gpio-sck", 0); + pdata->miso = of_get_named_gpio(np, "gpio-miso", 0); + pdata->mosi = of_get_named_gpio(np, "gpio-mosi", 0); + + ret = of_property_read_u32(np, "num-chipselects", &tmp); + if (ret < 0) { + dev_err(&pdev->dev, "num-chipselects property not found\n"); + goto error_free; + } + + pdata->num_chipselect = tmp; + pdev->dev.platform_data = pdata; + + return 1; + +error_free: + devm_kfree(&pdev->dev, pdata); + return ret; +} +#else +static inline int spi_probe_dt(struct platform_device *) +{ + return 0; +} +#endif + static int __devinit spi_gpio_probe(struct platform_device *pdev) { int status; @@ -333,6 +399,13 @@ static int __devinit spi_gpio_probe(struct platform_device *pdev) struct spi_gpio *spi_gpio; struct spi_gpio_platform_data *pdata; u16 master_flags = 0; + bool use_of = 0; + + status = spi_gpio_probe_dt(pdev); + if (status < 0) + return status; + if (status > 0) + use_of = 1; pdata = pdev->dev.platform_data; #ifdef GENERIC_BITBANG @@ -362,6 +435,23 @@ static int __devinit spi_gpio_probe(struct platform_device *pdev) master->num_chipselect = SPI_N_CHIPSEL; master->setup = spi_gpio_setup; master->cleanup = spi_gpio_cleanup; +#ifdef CONFIG_OF + master->dev.of_node = pdev->dev.of_node; + + if (use_of) { + int i; + struct device_node *np = pdev->dev.of_node; + + /* + * In DT environments, take the CS GPIO from the "cs-gpios" + * property of the node. + */ + + for (i = 0; i < SPI_N_CHIPSEL; i++) + spi_gpio->cs_gpios[i] = + of_get_named_gpio(np, "cs-gpios", i); + } +#endif spi_gpio->bitbang.master = spi_master_get(master); spi_gpio->bitbang.chipselect = spi_gpio_chipselect; @@ -422,8 +512,11 @@ static int __devexit spi_gpio_remove(struct platform_device *pdev) MODULE_ALIAS("platform:" DRIVER_NAME); static struct platform_driver spi_gpio_driver = { - .driver.name = DRIVER_NAME, - .driver.owner = THIS_MODULE, + .driver = { + .name = DRIVER_NAME, + .owner = THIS_MODULE, + .of_match_table = of_match_ptr(spi_gpio_dt_ids), + }, .probe = spi_gpio_probe, .remove = __devexit_p(spi_gpio_remove), }; |