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

[randy.dunlap@oracle.com: fix build when GPIOLIB is not enabled]
Signed-off-by: Joachim Eastwood <joachim.eastwood@jotron.com>
Reviewed-by: Wolfram Sang <w.sang@pengutronix.de>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Jan Weitzel <j.weitzel@phytec.de>
Cc: Juergen Kilb <j.kilb@phytec.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Joachim Eastwood authored and Linus Torvalds committed May 25, 2011
1 parent fff26f8 commit 3c1ab50
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Showing 3 changed files with 122 additions and 4 deletions.
10 changes: 10 additions & 0 deletions drivers/leds/Kconfig
View file
Original file line number Diff line number Diff line change
Expand Up @@ -162,6 +162,16 @@ config LEDS_PCA9532
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
Expand Down
113 changes: 110 additions & 3 deletions drivers/leds/leds-pca9532.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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
Expand All @@ -34,6 +36,9 @@ struct pca9532_data {
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];
};
Expand Down Expand Up @@ -200,16 +205,68 @@ static void pca9532_led_work(struct work_struct *work)
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);
Expand All @@ -224,12 +281,26 @@ static void pca9532_destroy_devices(struct pca9532_data *data, int n_devs)
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];
Expand All @@ -249,6 +320,9 @@ 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;
Expand Down Expand Up @@ -297,6 +371,34 @@ static int pca9532_configure(struct i2c_client *client,
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:
Expand Down Expand Up @@ -337,7 +439,12 @@ 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;
}
Expand Down
3 changes: 2 additions & 1 deletion include/linux/leds-pca9532.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand All @@ -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 */
Expand Down

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