diff options
| -rw-r--r-- | Documentation/devicetree/bindings/w1/w1-gpio.txt | 22 | ||||
| -rw-r--r-- | drivers/w1/masters/w1-gpio.c | 48 |
2 files changed, 69 insertions, 1 deletions
diff --git a/Documentation/devicetree/bindings/w1/w1-gpio.txt b/Documentation/devicetree/bindings/w1/w1-gpio.txt new file mode 100644 index 000000000000..6e09c35d9f1a --- /dev/null +++ b/Documentation/devicetree/bindings/w1/w1-gpio.txt @@ -0,0 +1,22 @@ +w1-gpio devicetree bindings + +Required properties: + + - compatible: "w1-gpio" + - gpios: one or two GPIO specs: + - the first one is used as data I/O pin + - the second one is optional. If specified, it is used as + enable pin for an external pin pullup. + +Optional properties: + + - linux,open-drain: if specified, the data pin is considered in + open-drain mode. + +Examples: + + onewire@0 { + compatible = "w1-gpio"; + gpios = <&gpio 126 0>, <&gpio 105 0>; + }; + diff --git a/drivers/w1/masters/w1-gpio.c b/drivers/w1/masters/w1-gpio.c index df600d14974d..f01c336233da 100644 --- a/drivers/w1/masters/w1-gpio.c +++ b/drivers/w1/masters/w1-gpio.c @@ -14,6 +14,8 @@ #include <linux/slab.h> #include <linux/w1-gpio.h> #include <linux/gpio.h> +#include <linux/of_platform.h> +#include <linux/of_gpio.h> #include "../w1.h" #include "../w1_int.h" @@ -42,12 +44,55 @@ static u8 w1_gpio_read_bit(void *data) return gpio_get_value(pdata->pin) ? 1 : 0; } +#ifdef CONFIG_OF +static struct of_device_id w1_gpio_dt_ids[] = { + { .compatible = "w1-gpio" }, + {} +}; +MODULE_DEVICE_TABLE(of, w1_gpio_dt_ids); + +static int w1_gpio_probe_dt(struct platform_device *pdev) +{ + struct w1_gpio_platform_data *pdata = pdev->dev.platform_data; + struct device_node *np = pdev->dev.of_node; + const struct of_device_id *of_id = + of_match_device(w1_gpio_dt_ids, &pdev->dev); + + if (!of_id) + return 0; + + pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL); + if (!pdata) + return -ENOMEM; + + if (of_get_property(np, "linux,open-drain", NULL)) + pdata->is_open_drain = 1; + + pdata->pin = of_get_gpio(np, 0); + pdata->ext_pullup_enable_pin = of_get_gpio(np, 1); + pdev->dev.platform_data = pdata; + + return 0; +} +#else +static int w1_gpio_probe_dt(struct platform_device *pdev) +{ + return 0; +} +#endif + static int __init w1_gpio_probe(struct platform_device *pdev) { struct w1_bus_master *master; - struct w1_gpio_platform_data *pdata = pdev->dev.platform_data; + struct w1_gpio_platform_data *pdata; int err; + err = w1_gpio_probe_dt(pdev); + if (err < 0) + return err; + + pdata = pdev->dev.platform_data; + if (!pdata) return -ENXIO; @@ -135,6 +180,7 @@ static struct platform_driver w1_gpio_driver = { .driver = { .name = "w1-gpio", .owner = THIS_MODULE, + .of_match_table = of_match_ptr(w1_gpio_dt_ids), }, .remove = __exit_p(w1_gpio_remove), .suspend = w1_gpio_suspend, |