drivers/leds/leds-pca9532.c: add gpio capability

Allow 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 gpio only.

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.

[[e-mail]: fix build when GPIOLIB is not enabled]
Signed-off-by: Joachim Eastwood <[e-mail]>
Reviewed-by: Wolfram Sang <[e-mail]>
Reviewed-by: H Hartley Sweeten <[e-mail]>
Cc: Richard Purdie <[e-mail]>
Cc: Grant Likely <[e-mail]>
Signed-off-by: Randy Dunlap <[e-mail]>
Cc: Jan Weitzel <[e-mail]>
Cc: Juergen Kilb <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

drivers/leds/Kconfig

···
 	  LED controller. It is generally only useful
 	  as a platform driver
 
+config LEDS_PCA9532_GPIO
+	bool "Enable GPIO support for PCA9532"
+	depends on LEDS_PCA9532
+	depends on GPIOLIB
+	help
+	  Allow unused pins on PCA9532 to be used as gpio.
+
+	  To use a pin as gpio pca9532_type in pca9532_platform data needs to
+	  set to PCA9532_TYPE_GPIO.
+
 config LEDS_GPIO
 	tristate "LED Support for GPIO connected LEDs"
 	depends on LEDS_CLASS

drivers/leds/leds-pca9532.c

···
 #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
···
 	struct mutex update_lock;
 	struct input_dev *idev;
 	struct work_struct work;
+#ifdef CONFIG_LEDS_PCA9532_GPIO
+	struct gpio_chip gpio;
+#endif
 	u8 pwm[2];
 	u8 psc[2];
 };
···
 	pca9532_setled(led);
 }
 
-static void pca9532_destroy_devices(struct pca9532_data *data, int n_devs)
+#ifdef CONFIG_LEDS_PCA9532_GPIO
+static int pca9532_gpio_request_pin(struct gpio_chip *gc, unsigned offset)
+{
+	struct pca9532_data *data = container_of(gc, struct pca9532_data, gpio);
+	struct pca9532_led *led = &data->leds[offset];
+
+	if (led->type == PCA9532_TYPE_GPIO)
+		return 0;
+
+	return -EBUSY;
+}
+
+static void pca9532_gpio_set_value(struct gpio_chip *gc, unsigned offset, int val)
+{
+	struct pca9532_data *data = container_of(gc, struct pca9532_data, gpio);
+	struct pca9532_led *led = &data->leds[offset];
+
+	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 offset)
+{
+	struct pca9532_data *data = container_of(gc, struct pca9532_data, gpio);
+	unsigned char reg;
+
+	reg = i2c_smbus_read_byte_data(data->client, PCA9532_REG_INPUT(offset));
+
+	return !!(reg & (1 << (offset % 8)));
+}
+
+static int pca9532_gpio_direction_input(struct gpio_chip *gc, unsigned offset)
+{
+	/* To use as input ensure pin is not driven */
+	pca9532_gpio_set_value(gc, offset, 0);
+
+	return 0;
+}
+
+static int pca9532_gpio_direction_output(struct gpio_chip *gc, unsigned offset, int val)
+{
+	pca9532_gpio_set_value(gc, offset, val);
+
+	return 0;
+}
+#endif /* CONFIG_LEDS_PCA9532_GPIO */
+
+static int pca9532_destroy_devices(struct pca9532_data *data, int n_devs)
 {
 	int 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);
···
 			break;
 		}
 	}
+
+#ifdef CONFIG_LEDS_PCA9532_GPIO
+	if (data->gpio.dev) {
+		int err = gpiochip_remove(&data->gpio);
+		if (err) {
+			dev_err(&data->client->dev, "%s failed, %d\n",
+						"gpiochip_remove()", err);
+			return err;
+		}
+	}
+#endif
+
+	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];
···
 		led->type = pled->type;
 		switch (led->type) {
 		case PCA9532_TYPE_NONE:
+			break;
+		case PCA9532_TYPE_GPIO:
+			gpios++;
 			break;
 		case PCA9532_TYPE_LED:
 			led->state = pled->state;
···
 			break;
 		}
 	}
+
+#ifdef CONFIG_LEDS_PCA9532_GPIO
+	if (gpios) {
+		data->gpio.label = "gpio-pca9532";
+		data->gpio.direction_input = pca9532_gpio_direction_input;
+		data->gpio.direction_output = pca9532_gpio_direction_output;
+		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_warn(&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);
+		}
+	}
+#endif
+
 	return 0;
 
 exit:
···
 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;
 }

include/linux/leds-pca9532.h

···
 };
 
 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;
···
 	struct pca9532_led leds[16];
 	u8 pwm[2];
 	u8 psc[2];
+	int gpio_base;
 };
 
 #endif /* __LINUX_PCA9532_H */