onewire: w1-gpio: add DT bindings

This patch add DT bindings to the w1-gpio driver, along with some
documentation on how to use them.

Signed-off-by: Daniel Mack <zonque@gmail.com>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Acked-by: Ville Syrjälä <syrjala@sci.fi>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 47 insertions, 1 deletions

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,