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leds: pca955x: Add brightness_get function

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Add a function to fetch the state of the hardware LED.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
Signed-off-by: Pavel Machek <pavel@ucw.cz>
This commit is contained in:
Eddie James 2021-07-16 17:03:28 -05:00 committed by Pavel Machek
parent 2420ae02ce
commit 7086625fde
1 changed files with 52 additions and 0 deletions
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52
drivers/leds/leds-pca955x.c
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@ -233,6 +233,57 @@ static int pca955x_read_ls(struct i2c_client *client, int n, u8 *val)
return 0;
}
static int pca955x_read_pwm(struct i2c_client *client, int n, u8 *val)
{
struct pca955x *pca955x = i2c_get_clientdata(client);
u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + 1 + (2 * n);
int ret;
ret = i2c_smbus_read_byte_data(client, cmd);
if (ret < 0) {
dev_err(&client->dev, "%s: reg 0x%x, err %d\n",
__func__, n, ret);
return ret;
}
*val = (u8)ret;
return 0;
}
static enum led_brightness pca955x_led_get(struct led_classdev *led_cdev)
{
struct pca955x_led *pca955x_led = container_of(led_cdev,
struct pca955x_led,
led_cdev);
struct pca955x *pca955x = pca955x_led->pca955x;
u8 ls, pwm;
int ret;
ret = pca955x_read_ls(pca955x->client, pca955x_led->led_num / 4, &ls);
if (ret)
return ret;
ls = (ls >> ((pca955x_led->led_num % 4) << 1)) & 0x3;
switch (ls) {
case PCA955X_LS_LED_ON:
ret = LED_FULL;
break;
case PCA955X_LS_LED_OFF:
ret = LED_OFF;
break;
case PCA955X_LS_BLINK0:
ret = LED_HALF;
break;
case PCA955X_LS_BLINK1:
ret = pca955x_read_pwm(pca955x->client, 1, &pwm);
if (ret)
return ret;
ret = 255 - pwm;
break;
}
return ret;
}
static int pca955x_led_set(struct led_classdev *led_cdev,
enum led_brightness value)
{
@ -512,6 +563,7 @@ static int pca955x_probe(struct i2c_client *client,
led->name = pca955x_led->name;
led->brightness_set_blocking = pca955x_led_set;
led->brightness_get = pca955x_led_get;
err = devm_led_classdev_register(&client->dev, led);
if (err)