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leds-pca9633: Add mutex to the ledout register 

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 adds a common mutex to all the leds of the same chip to
protect the ledout register.

Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Bryan Wu <cooloney@gmail.com>
This commit is contained in:
Ricardo Ribalda Delgado 2013-08-14 14:23:49 -07:00 committed by Bryan Wu
parent a5cd98b796
commit a7d0e9884f
1 changed files with 55 additions and 31 deletions
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86
drivers/leds/leds-pca9633.c
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@ -93,9 +93,17 @@ enum pca9633_cmd {
BLINK_SET, BLINK_SET,
}; };
struct pca9633_led { struct pca9633_led;
struct i2c_client *client;
struct pca9633 {
struct pca9633_chipdef *chipdef; 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; struct work_struct work;
enum led_brightness brightness; enum led_brightness brightness;
struct led_classdev led_cdev; struct led_classdev led_cdev;
@ -108,52 +116,60 @@ struct pca9633_led {
static void pca9633_brightness_work(struct pca9633_led *pca9633) static void pca9633_brightness_work(struct pca9633_led *pca9633)
{ {
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; u8 ledout;
int shift = 2 * (pca9633->led_num % 4); int shift = 2 * (pca9633->led_num % 4);
u8 mask = 0x3 << shift; 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) { switch (pca9633->brightness) {
case LED_FULL: 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)); (ledout & ~mask) | (PCA9633_LED_ON << shift));
break; break;
case LED_OFF: case LED_OFF:
i2c_smbus_write_byte_data(pca9633->client, ledout_addr, i2c_smbus_write_byte_data(pca9633->chip->client, ledout_addr,
ledout & ~mask); ledout & ~mask);
break; break;
default: default:
i2c_smbus_write_byte_data(pca9633->client, i2c_smbus_write_byte_data(pca9633->chip->client,
PCA9633_PWM_BASE + pca9633->led_num, PCA9633_PWM_BASE + pca9633->led_num,
pca9633->brightness); 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)); (ledout & ~mask) | (PCA9633_LED_PWM << shift));
break; break;
} }
mutex_unlock(&pca9633->chip->mutex);
} }
static void pca9633_blink_work(struct pca9633_led *pca9633) static void pca9633_blink_work(struct pca9633_led *pca9633)
{ {
u8 ledout_addr = pca9633->chipdef->ledout_base + (pca9633->led_num / 4); u8 ledout_addr = pca9633->chip->chipdef->ledout_base +
u8 ledout = i2c_smbus_read_byte_data(pca9633->client, ledout_addr); (pca9633->led_num / 4);
u8 mode2 = i2c_smbus_read_byte_data(pca9633->client, PCA9633_MODE2); u8 ledout;
u8 mode2 = i2c_smbus_read_byte_data(pca9633->chip->client,
PCA9633_MODE2);
int shift = 2 * (pca9633->led_num % 4); int shift = 2 * (pca9633->led_num % 4);
u8 mask = 0x3 << shift; u8 mask = 0x3 << shift;
i2c_smbus_write_byte_data(pca9633->client, pca9633->chipdef->grppwm, i2c_smbus_write_byte_data(pca9633->chip->client,
pca9633->gdc); pca9633->chip->chipdef->grppwm, pca9633->gdc);
i2c_smbus_write_byte_data(pca9633->client, pca9633->chipdef->grpfreq, i2c_smbus_write_byte_data(pca9633->chip->client,
pca9633->gfrq); pca9633->chip->chipdef->grpfreq, pca9633->gfrq);
if (!(mode2 & PCA9633_MODE2_DMBLNK)) if (!(mode2 & PCA9633_MODE2_DMBLNK))
i2c_smbus_write_byte_data(pca9633->client, PCA9633_MODE2, i2c_smbus_write_byte_data(pca9633->chip->client, PCA9633_MODE2,
mode2 | PCA9633_MODE2_DMBLNK); mode2 | PCA9633_MODE2_DMBLNK);
mutex_lock(&pca9633->chip->mutex);
ledout = i2c_smbus_read_byte_data(pca9633->chip->client, ledout_addr);
if ((ledout & mask) != (PCA9633_LED_GRP_PWM << shift)) if ((ledout & mask) != (PCA9633_LED_GRP_PWM << shift))
i2c_smbus_write_byte_data(pca9633->client, ledout_addr, i2c_smbus_write_byte_data(pca9633->chip->client, ledout_addr,
(ledout & ~mask) | (PCA9633_LED_GRP_PWM << shift)); (ledout & ~mask) | (PCA9633_LED_GRP_PWM << shift));
mutex_unlock(&pca9633->chip->mutex);
} }
static void pca9633_work(struct work_struct *work) static void pca9633_work(struct work_struct *work)
@ -318,6 +334,7 @@ pca9633_dt_init(struct i2c_client *client, struct pca9633_chipdef *chip)
static int pca9633_probe(struct i2c_client *client, static int pca9633_probe(struct i2c_client *client,
const struct i2c_device_id *id) const struct i2c_device_id *id)
{ {
struct pca9633 *pca9633_chip;
struct pca9633_led *pca9633; struct pca9633_led *pca9633;
struct pca9633_platform_data *pdata; struct pca9633_platform_data *pdata;
struct pca9633_chipdef *chip; struct pca9633_chipdef *chip;
@ -341,17 +358,30 @@ static int pca9633_probe(struct i2c_client *client,
return -EINVAL; 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), pca9633 = devm_kzalloc(&client->dev, chip->n_leds * sizeof(*pca9633),
GFP_KERNEL); GFP_KERNEL);
if (!pca9633) if (!pca9633)
return -ENOMEM; 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++) { for (i = 0; i < chip->n_leds; i++) {
pca9633[i].client = client;
pca9633[i].led_num = i; pca9633[i].led_num = i;
pca9633[i].chipdef = chip; pca9633[i].chip = pca9633_chip;
/* Platform data can specify LED names and default triggers */ /* Platform data can specify LED names and default triggers */
if (pdata && i < pdata->leds.num_leds) { if (pdata && i < pdata->leds.num_leds) {
@ -389,11 +419,6 @@ static int pca9633_probe(struct i2c_client *client,
if (pdata && pdata->outdrv == PCA9633_OPEN_DRAIN) if (pdata && pdata->outdrv == PCA9633_OPEN_DRAIN)
i2c_smbus_write_byte_data(client, PCA9633_MODE2, 0x01); 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; return 0;
exit: exit:
@ -407,14 +432,13 @@ static int pca9633_probe(struct i2c_client *client,
static int pca9633_remove(struct i2c_client *client) 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; int i;
for (i = 0; i < pca9633->chipdef->n_leds; i++) for (i = 0; i < pca9633->chipdef->n_leds; i++) {
if (pca9633[i].client != NULL) { led_classdev_unregister(&pca9633->leds[i].led_cdev);
led_classdev_unregister(&pca9633[i].led_cdev); cancel_work_sync(&pca9633->leds[i].work);
cancel_work_sync(&pca9633[i].work); }
}
return 0; return 0;
} }