Merge tag 'char-misc-3.6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh...

[deliverable/linux.git] / drivers / w1 / masters / w1-gpio.c

diff --git a/drivers/w1/masters/w1-gpio.c b/drivers/w1/masters/w1-gpio.c
index df600d14974d6ddcbe2ec00bdbb6b199b779537c..6012c4ea3206ac58e5d8c0efc561859b10c4b4b1 100644 (file)
--- 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;
 
@@ -59,6 +104,13 @@ static int __init w1_gpio_probe(struct platform_device *pdev)
        if (err)
                goto free_master;
 
+       if (gpio_is_valid(pdata->ext_pullup_enable_pin)) {
+               err = gpio_request_one(pdata->ext_pullup_enable_pin,
+                                      GPIOF_INIT_LOW, "w1 pullup");
+               if (err < 0)
+                       goto free_gpio;
+       }
+
        master->data = pdata;
        master->read_bit = w1_gpio_read_bit;
 
@@ -72,15 +124,21 @@ static int __init w1_gpio_probe(struct platform_device *pdev)
 
        err = w1_add_master_device(master);
        if (err)
-               goto free_gpio;
+               goto free_gpio_ext_pu;
 
        if (pdata->enable_external_pullup)
                pdata->enable_external_pullup(1);
 
+       if (gpio_is_valid(pdata->ext_pullup_enable_pin))
+               gpio_set_value(pdata->ext_pullup_enable_pin, 1);
+
        platform_set_drvdata(pdev, master);
 
        return 0;
 
+ free_gpio_ext_pu:
+       if (gpio_is_valid(pdata->ext_pullup_enable_pin))
+               gpio_free(pdata->ext_pullup_enable_pin);
  free_gpio:
        gpio_free(pdata->pin);
  free_master:
@@ -97,6 +155,9 @@ static int __exit w1_gpio_remove(struct platform_device *pdev)
        if (pdata->enable_external_pullup)
                pdata->enable_external_pullup(0);
 
+       if (gpio_is_valid(pdata->ext_pullup_enable_pin))
+               gpio_set_value(pdata->ext_pullup_enable_pin, 0);
+
        w1_remove_master_device(master);
        gpio_free(pdata->pin);
        kfree(master);
@@ -135,6 +196,7 @@ 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,