[PATCH 2/2] onewire: w1-gpio: add DT bindings

From: Daniel Mack
Date: Wed Jul 25 2012 - 16:54:32 EST


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@xxxxxxxxx>
Cc: Evgeniy Polyakov <zbr@xxxxxxxxxxx>
Cc: Ville Syrjala <syrjala@xxxxxx>
---
Documentation/devicetree/bindings/w1/w1-gpio.txt | 22 +++++++++++
drivers/w1/masters/w1-gpio.c | 46 ++++++++++++++++++++++
2 files changed, 68 insertions(+)
create mode 100644 Documentation/devicetree/bindings/w1/w1-gpio.txt

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 dac88ff..c4644b4 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;
int err;

+ err = w1_gpio_probe_dt(pdev);
+ if (err < 0)
+ return err;
+
+ pdata = pdev->dev.platform_data;
+
if (!pdata)
return -ENXIO;

@@ -151,6 +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,
--
1.7.10.4

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/