diff options
Diffstat (limited to 'target/linux/generic/backport-5.10/842-v5.15-leds-pca955x-implement-the-default-state-property.patch')
| -rw-r--r-- | target/linux/generic/backport-5.10/842-v5.15-leds-pca955x-implement-the-default-state-property.patch | 119 |
1 files changed, 119 insertions, 0 deletions
diff --git a/target/linux/generic/backport-5.10/842-v5.15-leds-pca955x-implement-the-default-state-property.patch b/target/linux/generic/backport-5.10/842-v5.15-leds-pca955x-implement-the-default-state-property.patch new file mode 100644 index 0000000000..055801f096 --- /dev/null +++ b/target/linux/generic/backport-5.10/842-v5.15-leds-pca955x-implement-the-default-state-property.patch @@ -0,0 +1,119 @@ +From e46cb6d0c760a5b15e38138845fad99628fafcb8 Mon Sep 17 00:00:00 2001 +From: Eddie James <eajames@linux.ibm.com> +Date: Fri, 16 Jul 2021 17:03:29 -0500 +Subject: [PATCH] leds: pca955x: Implement the default-state property + +In order to retain the LED state after a system reboot, check the +documented default-state device tree property during initialization. +Modify the behavior of the probe according to the property. + +Signed-off-by: Eddie James <eajames@linux.ibm.com> +Signed-off-by: Pavel Machek <pavel@ucw.cz> +--- + drivers/leds/leds-pca955x.c | 54 +++++++++++++++++++++++++++++++------ + 1 file changed, 46 insertions(+), 8 deletions(-) + +diff --git a/drivers/leds/leds-pca955x.c b/drivers/leds/leds-pca955x.c +index e47ba7c3b7c7d8..fa1d77d86ef67b 100644 +--- a/drivers/leds/leds-pca955x.c ++++ b/drivers/leds/leds-pca955x.c +@@ -129,6 +129,7 @@ struct pca955x_led { + int led_num; /* 0 .. 15 potentially */ + char name[32]; + u32 type; ++ int default_state; + const char *default_trigger; + }; + +@@ -439,6 +440,7 @@ pca955x_get_pdata(struct i2c_client *client, struct pca955x_chipdef *chip) + + device_for_each_child_node(&client->dev, child) { + const char *name; ++ const char *state; + u32 reg; + int res; + +@@ -457,6 +459,18 @@ pca955x_get_pdata(struct i2c_client *client, struct pca955x_chipdef *chip) + fwnode_property_read_u32(child, "type", &led->type); + fwnode_property_read_string(child, "linux,default-trigger", + &led->default_trigger); ++ ++ if (!fwnode_property_read_string(child, "default-state", ++ &state)) { ++ if (!strcmp(state, "keep")) ++ led->default_state = LEDS_GPIO_DEFSTATE_KEEP; ++ else if (!strcmp(state, "on")) ++ led->default_state = LEDS_GPIO_DEFSTATE_ON; ++ else ++ led->default_state = LEDS_GPIO_DEFSTATE_OFF; ++ } else { ++ led->default_state = LEDS_GPIO_DEFSTATE_OFF; ++ } + } + + pdata->num_leds = chip->bits; +@@ -485,6 +499,7 @@ static int pca955x_probe(struct i2c_client *client, + int i, err; + struct pca955x_platform_data *pdata; + int ngpios = 0; ++ bool keep_pwm = false; + + chip = &pca955x_chipdefs[id->driver_data]; + adapter = client->adapter; +@@ -565,14 +580,35 @@ static int pca955x_probe(struct i2c_client *client, + led->brightness_set_blocking = pca955x_led_set; + led->brightness_get = pca955x_led_get; + ++ if (pdata->leds[i].default_state == ++ LEDS_GPIO_DEFSTATE_OFF) { ++ err = pca955x_led_set(led, LED_OFF); ++ if (err) ++ return err; ++ } else if (pdata->leds[i].default_state == ++ LEDS_GPIO_DEFSTATE_ON) { ++ err = pca955x_led_set(led, LED_FULL); ++ if (err) ++ return err; ++ } ++ + err = devm_led_classdev_register(&client->dev, led); + if (err) + return err; + +- /* Turn off LED */ +- err = pca955x_led_set(led, LED_OFF); +- if (err) +- return err; ++ /* ++ * For default-state == "keep", let the core update the ++ * brightness from the hardware, then check the ++ * brightness to see if it's using PWM1. If so, PWM1 ++ * should not be written below. ++ */ ++ if (pdata->leds[i].default_state == ++ LEDS_GPIO_DEFSTATE_KEEP) { ++ if (led->brightness != LED_FULL && ++ led->brightness != LED_OFF && ++ led->brightness != LED_HALF) ++ keep_pwm = true; ++ } + } + } + +@@ -581,10 +617,12 @@ static int pca955x_probe(struct i2c_client *client, + if (err) + return err; + +- /* PWM1 is used for variable brightness, default to OFF */ +- err = pca955x_write_pwm(client, 1, 0); +- if (err) +- return err; ++ if (!keep_pwm) { ++ /* PWM1 is used for variable brightness, default to OFF */ ++ err = pca955x_write_pwm(client, 1, 0); ++ if (err) ++ return err; ++ } + + /* Set to fast frequency so we do not see flashing */ + err = pca955x_write_psc(client, 0, 0); |