gpio: pcf857x: Add OF support

Add DT bindings for the pcf857x-compatible chips and parse the device
tree node in the driver.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This commit is contained in:
Laurent Pinchart
2013-09-21 20:39:49 +02:00
committed by Linus Walleij
parent e5304db8d7
commit 63f57cd45b
2 changed files with 107 additions and 8 deletions

View File

@@ -26,6 +26,8 @@
#include <linux/irqdomain.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
@@ -49,6 +51,27 @@ static const struct i2c_device_id pcf857x_id[] = {
};
MODULE_DEVICE_TABLE(i2c, pcf857x_id);
#ifdef CONFIG_OF
static const struct of_device_id pcf857x_of_table[] = {
{ .compatible = "nxp,pcf8574" },
{ .compatible = "nxp,pcf8574a" },
{ .compatible = "nxp,pca8574" },
{ .compatible = "nxp,pca9670" },
{ .compatible = "nxp,pca9672" },
{ .compatible = "nxp,pca9674" },
{ .compatible = "nxp,pcf8575" },
{ .compatible = "nxp,pca8575" },
{ .compatible = "nxp,pca9671" },
{ .compatible = "nxp,pca9673" },
{ .compatible = "nxp,pca9675" },
{ .compatible = "maxim,max7328" },
{ .compatible = "maxim,max7329" },
{ .compatible = "ti,tca9554" },
{ }
};
MODULE_DEVICE_TABLE(of, pcf857x_of_table);
#endif
/*
* The pcf857x, pca857x, and pca967x chips only expose one read and one
* write register. Writing a "one" bit (to match the reset state) lets
@@ -260,14 +283,18 @@ fail:
static int pcf857x_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct pcf857x_platform_data *pdata;
struct pcf857x_platform_data *pdata = dev_get_platdata(&client->dev);
struct device_node *np = client->dev.of_node;
struct pcf857x *gpio;
unsigned int n_latch = 0;
int status;
pdata = dev_get_platdata(&client->dev);
if (!pdata) {
if (IS_ENABLED(CONFIG_OF) && np)
of_property_read_u32(np, "lines-initial-states", &n_latch);
else if (pdata)
n_latch = pdata->n_latch;
else
dev_dbg(&client->dev, "no platform data\n");
}
/* Allocate, initialize, and register this gpio_chip. */
gpio = devm_kzalloc(&client->dev, sizeof(*gpio), GFP_KERNEL);
@@ -360,11 +387,11 @@ static int pcf857x_probe(struct i2c_client *client,
* may cause transient glitching since it can't know the last value
* written (some pins may need to be driven low).
*
* Using pdata->n_latch avoids that trouble. When left initialized
* to zero, our software copy of the "latch" then matches the chip's
* all-ones reset state. Otherwise it flags pins to be driven low.
* Using n_latch avoids that trouble. When left initialized to zero,
* our software copy of the "latch" then matches the chip's all-ones
* reset state. Otherwise it flags pins to be driven low.
*/
gpio->out = pdata ? ~pdata->n_latch : ~0;
gpio->out = ~n_latch;
gpio->status = gpio->out;
status = gpiochip_add(&gpio->chip);
@@ -426,6 +453,7 @@ static struct i2c_driver pcf857x_driver = {
.driver = {
.name = "pcf857x",
.owner = THIS_MODULE,
.of_match_table = of_match_ptr(pcf857x_of_table),
},
.probe = pcf857x_probe,
.remove = pcf857x_remove,