To update an LED a register has to be read, updated and writen. If
another LED whas been updated at the same time, this could lead into
wrong updates.
This patch addes a common mutex to all the leds of the same chip to
protect the ledout register.
Signed-off-by: Ricardo Ribalda Delgado <ricardo.riba...@gmail.com>
---
drivers/leds/leds-pca9633.c | 63 ++++++++++++++++++++++++++++---------------
1 file changed, 41 insertions(+), 22 deletions(-)
diff --git a/drivers/leds/leds-pca9633.c b/drivers/leds/leds-pca9633.c
index 4dd7793..5e3d36f 100644
--- a/drivers/leds/leds-pca9633.c
+++ b/drivers/leds/leds-pca9633.c
@@ -65,9 +65,17 @@ static const struct i2c_device_id pca9633_id[] = {
};
MODULE_DEVICE_TABLE(i2c, pca9633_id);
-struct pca9633_led {
- struct i2c_client *client;
+struct pca9633_led;
+
+struct pca9633 {
struct pca9633_chipdef *chipdef;
+ struct mutex mutex;
+ struct i2c_client *client;
+ struct pca9633_led *leds;
+};
+
+struct pca9633_led {
+ struct pca9633 *chip;
struct work_struct work;
enum led_brightness brightness;
struct led_classdev led_cdev;
@@ -79,29 +87,32 @@ static void pca9633_led_work(struct work_struct *work)
{
struct pca9633_led *pca9633 = container_of(work,
struct pca9633_led, work);
- u8 ledout_addr = pca9633->chipdef->ledout_base + (pca9633->led_num / 4);
+ u8 ledout_addr = pca9633->chip->chipdef->ledout_base
+ + (pca9633->led_num / 4);
u8 ledout;
int shift = 2 * (pca9633->led_num % 4);
u8 mask = 0x3 << shift;
- ledout = i2c_smbus_read_byte_data(pca9633->client, ledout_addr);
+ mutex_lock(&pca9633->chip->mutex);
+ ledout = i2c_smbus_read_byte_data(pca9633->chip->client, ledout_addr);
switch (pca9633->brightness) {
case LED_FULL:
- i2c_smbus_write_byte_data(pca9633->client, ledout_addr,
+ i2c_smbus_write_byte_data(pca9633->chip->client, ledout_addr,
(ledout & ~mask) | (PCA9633_LED_ON << shift));
break;
case LED_OFF:
- i2c_smbus_write_byte_data(pca9633->client, ledout_addr,
+ i2c_smbus_write_byte_data(pca9633->chip->client, ledout_addr,
ledout & ~mask);
break;
default:
- i2c_smbus_write_byte_data(pca9633->client,
+ i2c_smbus_write_byte_data(pca9633->chip->client,
PCA9633_PWM_BASE + pca9633->led_num,
pca9633->brightness);
- i2c_smbus_write_byte_data(pca9633->client, ledout_addr,
+ i2c_smbus_write_byte_data(pca9633->chip->client, ledout_addr,
(ledout & ~mask) | (PCA9633_LED_PWM << shift));
break;
}
+ mutex_unlock(&pca9633->chip->mutex);
}
static void pca9633_led_set(struct led_classdev *led_cdev,
@@ -123,6 +134,7 @@ static void pca9633_led_set(struct led_classdev *led_cdev,
static int pca9633_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
+ struct pca9633 *pca9633_chip;
struct pca9633_led *pca9633;
struct pca9633_platform_data *pdata;
struct pca9633_chipdef *chip;
@@ -138,17 +150,30 @@ static int pca9633_probe(struct i2c_client *client,
return -EINVAL;
}
+ pca9633_chip = devm_kzalloc(&client->dev, sizeof(*pca9633_chip),
+ GFP_KERNEL);
+ if (!pca9633_chip)
+ return -ENOMEM;
pca9633 = devm_kzalloc(&client->dev, chip->n_leds * sizeof(*pca9633),
GFP_KERNEL);
if (!pca9633)
return -ENOMEM;
- i2c_set_clientdata(client, pca9633);
+ i2c_set_clientdata(client, pca9633_chip);
+
+ mutex_init(&pca9633_chip->mutex);
+ pca9633_chip->chipdef = chip;
+ pca9633_chip->client = client;
+ pca9633_chip->leds = pca9633;
+
+ /* Turn off LEDs by default*/
+ i2c_smbus_write_byte_data(client, chip->ledout_base, 0x00);
+ if (chip->n_leds > 4)
+ i2c_smbus_write_byte_data(client, chip->ledout_base + 1, 0x00);
for (i = 0; i < chip->n_leds; i++) {
- pca9633[i].client = client;
pca9633[i].led_num = i;
- pca9633[i].chipdef = chip;
+ pca9633[i].chip = pca9633_chip;
/* Platform data can specify LED names and default triggers */
if (pdata && i < pdata->leds.num_leds) {
@@ -182,11 +207,6 @@ static int pca9633_probe(struct i2c_client *client,
if (pdata && pdata->outdrv == PCA9633_OPEN_DRAIN)
i2c_smbus_write_byte_data(client, PCA9633_MODE2, 0x01);
- /* Turn off LEDs */
- i2c_smbus_write_byte_data(client, chip->ledout_base, 0x00);
- if (chip->n_leds > 4)
- i2c_smbus_write_byte_data(client, chip->ledout_base + 1, 0x00);
-
return 0;
exit:
@@ -200,14 +220,13 @@ exit:
static int pca9633_remove(struct i2c_client *client)
{
- struct pca9633_led *pca9633 = i2c_get_clientdata(client);
+ struct pca9633 *pca9633 = i2c_get_clientdata(client);
int i;
- for (i = 0; i < pca9633->chipdef->n_leds; i++)
- if (pca9633[i].client != NULL) {
- led_classdev_unregister(&pca9633[i].led_cdev);
- cancel_work_sync(&pca9633[i].work);
- }
+ for (i = 0; i < pca9633->chipdef->n_leds; i++) {
+ led_classdev_unregister(&pca9633->leds[i].led_cdev);
+ cancel_work_sync(&pca9633->leds[i].work);
+ }
return 0;
}
--
1.7.10.4
--
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