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| author | Eddie James <eajames@linux.ibm.com> | 2021-07-16 17:03:28 -0500 |
|---|---|---|
| committer | Pavel Machek <pavel@ucw.cz> | 2021-08-20 11:00:07 +0200 |
| commit | 7086625fde6538b2c0623eb767ad23c7ac3d7f3a (patch) | |
| tree | b8f98f77b42111b85af6f752843d20f86ad054ae /drivers/leds/leds-pca955x.c | |
| parent | 2420ae02ce0a926819ebe18f809a57bff3edeac2 (diff) | |
| download | lwn-7086625fde6538b2c0623eb767ad23c7ac3d7f3a.tar.gz lwn-7086625fde6538b2c0623eb767ad23c7ac3d7f3a.zip | |
leds: pca955x: Add brightness_get function
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>
Diffstat (limited to 'drivers/leds/leds-pca955x.c')
| -rw-r--r-- | drivers/leds/leds-pca955x.c | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/drivers/leds/leds-pca955x.c b/drivers/leds/leds-pca955x.c index f0d841cb59fc..e47ba7c3b7c7 100644 --- a/drivers/leds/leds-pca955x.c +++ b/drivers/leds/leds-pca955x.c @@ -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) |