Messages in this thread Patch in this message | | | Date | Sun, 30 Jan 2011 18:31:30 +0100 | Subject | [leds-pca9532] Add gpio capability | From | Joachim Eastwood <> |
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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@jotron.com>
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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