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>
diff --git a/Documentation/devicetree/bindings/w1/w1-gpio.txt b/Documentation/devicetree/bindings/w1/w1-gpio.txt
new file mode 100644
index 0000000..6e09c35
--- /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 df600d1..f01c336 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 @@
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 @@
.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,