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gpio: pca953x: Get platform_data from OpenFirmware 

On OpenFirmware platforms, it makes the most sense to get platform_data
from the device tree.  Make an attempt to translate OF node properties
into platform_data struct before bailing out.

Note that the implementation approach taken differs from other device
drivers that make use of device tree information.  This is because I2C
chips are already registered automatically by of_i2c, so we can get by
with a small translator function in the driver.

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: kfree(NULL) is legal]
Signed-off-by: Nate Case <ncase@xes-inc.com>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Nate Case 2009-06-17 16:26:17 -07:00 committed by Linus Torvalds
parent de3483b071
commit 1965d30356
1 changed files with 71 additions and 6 deletions
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77
drivers/gpio/pca953x.c
View File

@ -15,6 +15,10 @@
#include <linux/init.h>
#include <linux/i2c.h>
#include <linux/i2c/pca953x.h>
#ifdef CONFIG_OF_GPIO
#include <linux/of_platform.h>
#include <linux/of_gpio.h>
#endif
#include <asm/gpio.h>
@ -49,6 +53,7 @@ struct pca953x_chip {
uint16_t reg_direction;
struct i2c_client *client;
struct pca953x_platform_data *dyn_pdata;
struct gpio_chip gpio_chip;
char **names;
};
@ -196,6 +201,54 @@ static void pca953x_setup_gpio(struct pca953x_chip *chip, int gpios)
gc->names = chip->names;
}
/*
* Handlers for alternative sources of platform_data
*/
#ifdef CONFIG_OF_GPIO
/*
* Translate OpenFirmware node properties into platform_data
*/
static struct pca953x_platform_data *
pca953x_get_alt_pdata(struct i2c_client *client)
{
struct pca953x_platform_data *pdata;
struct device_node *node;
const uint16_t *val;
node = dev_archdata_get_node(&client->dev.archdata);
if (node == NULL)
return NULL;
pdata = kzalloc(sizeof(struct pca953x_platform_data), GFP_KERNEL);
if (pdata == NULL) {
dev_err(&client->dev, "Unable to allocate platform_data\n");
return NULL;
}
pdata->gpio_base = -1;
val = of_get_property(node, "linux,gpio-base", NULL);
if (val) {
if (*val < 0)
dev_warn(&client->dev,
"invalid gpio-base in device tree\n");
else
pdata->gpio_base = *val;
}
val = of_get_property(node, "polarity", NULL);
if (val)
pdata->invert = *val;
return pdata;
}
#else
static struct pca953x_platform_data *
pca953x_get_alt_pdata(struct i2c_client *client)
{
return NULL;
}
#endif
static int __devinit pca953x_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
@ -203,16 +256,26 @@ static int __devinit pca953x_probe(struct i2c_client *client,
struct pca953x_chip *chip;
int ret;
pdata = client->dev.platform_data;
if (pdata == NULL) {
dev_dbg(&client->dev, "no platform data\n");
return -EINVAL;
}
chip = kzalloc(sizeof(struct pca953x_chip), GFP_KERNEL);
if (chip == NULL)
return -ENOMEM;
pdata = client->dev.platform_data;
if (pdata == NULL) {
pdata = pca953x_get_alt_pdata(client);
/*
* Unlike normal platform_data, this is allocated
* dynamically and must be freed in the driver
*/
chip->dyn_pdata = pdata;
}
if (pdata == NULL) {
dev_dbg(&client->dev, "no platform data\n");
ret = -EINVAL;
goto out_failed;
}
chip->client = client;
chip->gpio_start = pdata->gpio_base;
@ -253,6 +316,7 @@ static int __devinit pca953x_probe(struct i2c_client *client,
return 0;
out_failed:
kfree(chip->dyn_pdata);
kfree(chip);
return ret;
}
@ -280,6 +344,7 @@ static int pca953x_remove(struct i2c_client *client)
return ret;
}
kfree(chip->dyn_pdata);
kfree(chip);
return 0;
}