[leds-pca9532] Add gpio capability
From: Joachim Eastwood
Date: Sun Jan 30 2011 - 12:31:48 EST
Hello,
The patch below allows unused leds on pca9532 to be used as gpio. The
board I am working on now has no less than 6 pca9532 chips. One chips
is used for only leds, one has 14 leds and 2 gpio and the rest of the
chips are pure gpio.
There is also one board in mainline which could use this capabilty;
arch/arm/mach-iop32x/n2100.c
232 { .type = PCA9532_TYPE_NONE }, /* power OFF gpio */
233 { .type = PCA9532_TYPE_NONE }, /* reset gpio */
This patch defines a new pin type, PCA9532_TYPE_GPIO, and registers a
gpiochip if any pin has this type set. The gpio will registers all
chip pins but will filter on gpio_request.
Since it is a bug to call get/set value on unrequested gpio's the
check for PCA9532_TYPE_GPIO could be removed from
pca9532_gpio_get_value/pca9532_gpio_set_value functions. But I have
kept it for this posting.
Tested on custom ARM board.
-------------------------------------------------------------------
[leds-pca9532] Add gpio capability
Pins not used for leds can now be used as gpio by setting pin type as
PCA9532_TYPE_GPIO and defining a gpio_base in platform data.
Signed-off-by: Joachim Eastwood <joachim.eastwood@xxxxxxxxxx>
diff --git a/drivers/leds/leds-pca9532.c b/drivers/leds/leds-pca9532.c
index afac338..b036fa5 100644
--- a/drivers/leds/leds-pca9532.c
+++ b/drivers/leds/leds-pca9532.c
@@ -19,7 +19,9 @@
#include <linux/mutex.h>
#include <linux/workqueue.h>
#include <linux/leds-pca9532.h>
+#include <linux/gpio.h>
+#define PCA9532_REG_INPUT(i) ((i)/8)
#define PCA9532_REG_PSC(i) (0x2+(i)*2)
#define PCA9532_REG_PWM(i) (0x3+(i)*2)
#define PCA9532_REG_LS0 0x6
@@ -34,6 +36,7 @@ struct pca9532_data {
struct mutex update_lock;
struct input_dev *idev;
struct work_struct work;
+ struct gpio_chip gpio;
u8 pwm[2];
u8 psc[2];
};
@@ -200,16 +203,58 @@ static void pca9532_led_work(struct work_struct *work)
pca9532_setled(led);
}
-static void pca9532_destroy_devices(struct pca9532_data *data, int n_devs)
+static int pca9532_gpio_request_pin(struct gpio_chip *gc, unsigned off)
{
- int i = n_devs;
+ struct pca9532_data *data = container_of(gc, struct pca9532_data, gpio);
+ struct pca9532_led *led = &data->leds[off];
+
+ if (led->type == PCA9532_TYPE_GPIO)
+ return 0;
+
+ return -EINVAL;
+}
+
+static void pca9532_gpio_set_value(struct gpio_chip *gc, unsigned off, int val)
+{
+ struct pca9532_data *data = container_of(gc, struct pca9532_data, gpio);
+ struct pca9532_led *led = &data->leds[off];
+
+ if (led->type == PCA9532_TYPE_GPIO) {
+ if (val)
+ led->state = PCA9532_ON;
+ else
+ led->state = PCA9532_OFF;
+
+ pca9532_setled(led);
+ }
+}
+
+static int pca9532_gpio_get_value(struct gpio_chip *gc, unsigned off)
+{
+ struct pca9532_data *data = container_of(gc, struct pca9532_data, gpio);
+ struct pca9532_led *led = &data->leds[off];
+ unsigned char reg;
+
+ if (led->type == PCA9532_TYPE_GPIO) {
+ reg = i2c_smbus_read_byte_data(data->client,
+ PCA9532_REG_INPUT(off));
+ return !!(reg & (1<<(off % 8)));
+ }
+
+ return -1;
+}
+
+static int pca9532_destroy_devices(struct pca9532_data *data, int n_devs)
+{
+ int err, i = n_devs;
if (!data)
- return;
+ return -EINVAL;
while (--i >= 0) {
switch (data->leds[i].type) {
case PCA9532_TYPE_NONE:
+ case PCA9532_TYPE_GPIO:
break;
case PCA9532_TYPE_LED:
led_classdev_unregister(&data->leds[i].ldev);
@@ -224,12 +269,24 @@ static void pca9532_destroy_devices(struct
pca9532_data *data, int n_devs)
break;
}
}
+
+ if (data->gpio.dev) {
+ err = gpiochip_remove(&data->gpio);
+ if (err) {
+ dev_err(&data->client->dev, "%s failed, %d\n",
+ "gpiochip_remove()", err);
+ return err;
+ }
+ }
+
+ return 0;
}
static int pca9532_configure(struct i2c_client *client,
struct pca9532_data *data, struct pca9532_platform_data *pdata)
{
int i, err = 0;
+ int gpios = 0;
for (i = 0; i < 2; i++) {
data->pwm[i] = pdata->pwm[i];
@@ -249,6 +306,9 @@ static int pca9532_configure(struct i2c_client *client,
switch (led->type) {
case PCA9532_TYPE_NONE:
break;
+ case PCA9532_TYPE_GPIO:
+ gpios++;
+ break;
case PCA9532_TYPE_LED:
led->state = pled->state;
led->name = pled->name;
@@ -297,6 +357,30 @@ static int pca9532_configure(struct i2c_client *client,
break;
}
}
+
+ if (gpios) {
+ data->gpio.label = "gpio-pca9532";
+ data->gpio.set = pca9532_gpio_set_value;
+ data->gpio.get = pca9532_gpio_get_value;
+ data->gpio.request = pca9532_gpio_request_pin;
+ data->gpio.can_sleep = 1;
+ data->gpio.base = pdata->gpio_base;
+ data->gpio.ngpio = 16;
+ data->gpio.dev = &client->dev;
+ data->gpio.owner = THIS_MODULE;
+
+ err = gpiochip_add(&data->gpio);
+ if (err) {
+ /* Use data->gpio.dev as a flag for freeing gpiochip */
+ data->gpio.dev = NULL;
+ dev_info(&client->dev, "could not add gpiochip\n");
+ } else {
+ dev_info(&client->dev, "gpios %i...%i\n",
+ data->gpio.base, data->gpio.base +
+ data->gpio.ngpio - 1);
+ }
+ }
+
return 0;
exit:
@@ -337,7 +421,12 @@ static int pca9532_probe(struct i2c_client *client,
static int pca9532_remove(struct i2c_client *client)
{
struct pca9532_data *data = i2c_get_clientdata(client);
- pca9532_destroy_devices(data, 16);
+ int err;
+
+ err = pca9532_destroy_devices(data, 16);
+ if (err)
+ return err;
+
kfree(data);
return 0;
}
diff --git a/include/linux/leds-pca9532.h b/include/linux/leds-pca9532.h
index f158eb1..b8d6fff 100644
--- a/include/linux/leds-pca9532.h
+++ b/include/linux/leds-pca9532.h
@@ -25,7 +25,7 @@ enum pca9532_state {
};
enum pca9532_type { PCA9532_TYPE_NONE, PCA9532_TYPE_LED,
- PCA9532_TYPE_N2100_BEEP };
+ PCA9532_TYPE_N2100_BEEP, PCA9532_TYPE_GPIO };
struct pca9532_led {
u8 id;
@@ -41,6 +41,7 @@ struct pca9532_platform_data {
struct pca9532_led leds[16];
u8 pwm[2];
u8 psc[2];
+ int gpio_base;
};
#endif /* __LINUX_PCA9532_H */
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