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>
This commit is contained in:
Daniel Mack 2012-07-23 16:36:35 +02:00 committed by Greg Kroah-Hartman
parent 73f2989d37
commit 5f3d1382e3
2 changed files with 69 additions and 1 deletions

View file

@ -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>;
};

View file

@ -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,