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* [PATCH v7 2/3] leds: pwm: add support for default-state device property
  2020-07-31 16:51 [PATCH v7 0/3] leds: pwm: add support for default-state device Denis Osterland-Heim
@ 2020-07-31 16:51 ` Denis Osterland-Heim
  2020-07-31 16:51 ` [PATCH v7 3/3] leds: pwm: add reference to common leds for default-state Denis Osterland-Heim
  2020-07-31 16:51 ` [PATCH v7 1/3] leds: move default_state read from fwnode to core Denis Osterland-Heim
  2 siblings, 0 replies; 4+ messages in thread
From: Denis Osterland-Heim @ 2020-07-31 16:51 UTC (permalink / raw)
  To: dmurphy, pavel, jacek.anaszewski
  Cc: linux-kernel, Denis Osterland-Heim, linux-leds, robh+dt, devicetree

This patch adds support for "default-state" devicetree property, which
allows to defer pwm init to first use of led.

This allows to configure the PWM early in bootloader to let the LED
blink until an application in Linux userspace sets something different.

Signed-off-by: Denis Osterland-Heim <Denis.Osterland@diehl.com>
Acked-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
---
 drivers/leds/leds-pwm.c | 49 ++++++++++++++++++++++++++++++++++++-----
 1 file changed, 43 insertions(+), 6 deletions(-)

diff --git a/drivers/leds/leds-pwm.c b/drivers/leds/leds-pwm.c
index ef7b91bd2064..0c0470c90d5d 100644
--- a/drivers/leds/leds-pwm.c
+++ b/drivers/leds/leds-pwm.c
@@ -17,11 +17,13 @@
 #include <linux/err.h>
 #include <linux/pwm.h>
 #include <linux/slab.h>
+#include "leds.h"
 
 struct led_pwm {
 	const char	*name;
 	const char	*default_trigger;
 	u8		active_low;
+	u8		default_state;
 	unsigned int	max_brightness;
 };
 
@@ -88,7 +90,38 @@ static int led_pwm_add(struct device *dev, struct led_pwm_priv *priv,
 
 	led_data->cdev.brightness_set_blocking = led_pwm_set;
 
-	pwm_init_state(led_data->pwm, &led_data->pwmstate);
+	/* init PWM state */
+	switch (led->default_state) {
+	case LEDS_DEFSTATE_KEEP:
+		pwm_get_state(led_data->pwm, &led_data->pwmstate);
+		if (led_data->pwmstate.period)
+			break;
+		led->default_state = LEDS_DEFSTATE_OFF;
+		dev_warn(dev,
+			"failed to read period for %s, default to off",
+			led->name);
+		fallthrough;
+	default:
+		pwm_init_state(led_data->pwm, &led_data->pwmstate);
+		break;
+	}
+
+	/* set brightness */
+	switch (led->default_state) {
+	case LEDS_DEFSTATE_ON:
+		led_data->cdev.brightness = led->max_brightness;
+		break;
+	case LEDS_DEFSTATE_KEEP:
+		{
+		uint64_t brightness;
+
+		brightness = led->max_brightness;
+		brightness *= led_data->pwmstate.duty_cycle;
+		do_div(brightness, led_data->pwmstate.period);
+		led_data->cdev.brightness = brightness;
+		}
+		break;
+	}
 
 	ret = devm_led_classdev_register(dev, &led_data->cdev);
 	if (ret) {
@@ -97,11 +130,13 @@ static int led_pwm_add(struct device *dev, struct led_pwm_priv *priv,
 		return ret;
 	}
 
-	ret = led_pwm_set(&led_data->cdev, led_data->cdev.brightness);
-	if (ret) {
-		dev_err(dev, "failed to set led PWM value for %s: %d",
-			led->name, ret);
-		return ret;
+	if (led->default_state != LEDS_DEFSTATE_KEEP) {
+		ret = led_pwm_set(&led_data->cdev, led_data->cdev.brightness);
+		if (ret) {
+			dev_err(dev, "failed to set led PWM value for %s: %d",
+				led->name, ret);
+			return ret;
+		}
 	}
 
 	priv->num_leds++;
@@ -134,6 +169,8 @@ static int led_pwm_create_fwnode(struct device *dev, struct led_pwm_priv *priv)
 		fwnode_property_read_u32(fwnode, "max-brightness",
 					 &led.max_brightness);
 
+		led.default_state = led_init_default_state_get(fwnode);
+
 		ret = led_pwm_add(dev, priv, &led, fwnode);
 		if (ret) {
 			fwnode_handle_put(fwnode);
-- 
2.28.0



Diehl Connectivity Solutions GmbH
Geschäftsführung: Horst Leonberger
Sitz der Gesellschaft: Nürnberg - Registergericht: Amtsgericht
Nürnberg: HRB 32315
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^ permalink raw reply	[flat|nested] 4+ messages in thread

* [PATCH v7 3/3] leds: pwm: add reference to common leds for default-state
  2020-07-31 16:51 [PATCH v7 0/3] leds: pwm: add support for default-state device Denis Osterland-Heim
  2020-07-31 16:51 ` [PATCH v7 2/3] leds: pwm: add support for default-state device property Denis Osterland-Heim
@ 2020-07-31 16:51 ` Denis Osterland-Heim
  2020-07-31 16:51 ` [PATCH v7 1/3] leds: move default_state read from fwnode to core Denis Osterland-Heim
  2 siblings, 0 replies; 4+ messages in thread
From: Denis Osterland-Heim @ 2020-07-31 16:51 UTC (permalink / raw)
  To: dmurphy, pavel, jacek.anaszewski
  Cc: robh, linux-kernel, Denis Osterland-Heim, linux-leds, robh+dt,
	devicetree

The default-state is now supported for PWM leds.

Signed-off-by: Denis Osterland-Heim <Denis.Osterland@diehl.com>
Acked-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Acked-by: Rob Herring <robh@kernel.org>
---
 Documentation/devicetree/bindings/leds/leds-pwm.txt | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Documentation/devicetree/bindings/leds/leds-pwm.txt b/Documentation/devicetree/bindings/leds/leds-pwm.txt
index 6c6583c35f2f..d0f489680594 100644
--- a/Documentation/devicetree/bindings/leds/leds-pwm.txt
+++ b/Documentation/devicetree/bindings/leds/leds-pwm.txt
@@ -19,6 +19,8 @@ LED sub-node properties:
   see Documentation/devicetree/bindings/leds/common.txt
 - linux,default-trigger :  (optional)
   see Documentation/devicetree/bindings/leds/common.txt
+- default-state : (optional)
+  see Documentation/devicetree/bindings/leds/common.yaml
 
 Example:
 
-- 
2.28.0



Diehl Connectivity Solutions GmbH
Geschäftsführung: Horst Leonberger
Sitz der Gesellschaft: Nürnberg - Registergericht: Amtsgericht
Nürnberg: HRB 32315
___________________________________________________________________________________________________

Der Inhalt der vorstehenden E-Mail ist nicht rechtlich bindend. Diese E-Mail enthaelt vertrauliche und/oder rechtlich geschuetzte Informationen.
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^ permalink raw reply	[flat|nested] 4+ messages in thread

* [PATCH v7 0/3] leds: pwm: add support for default-state device
@ 2020-07-31 16:51 Denis Osterland-Heim
  2020-07-31 16:51 ` [PATCH v7 2/3] leds: pwm: add support for default-state device property Denis Osterland-Heim
                   ` (2 more replies)
  0 siblings, 3 replies; 4+ messages in thread
From: Denis Osterland-Heim @ 2020-07-31 16:51 UTC (permalink / raw)
  To: dmurphy, pavel, jacek.anaszewski
  Cc: linux-kernel, linux-leds, robh+dt, devicetree

v6 -> v7: apply comments from Jacek
           refactore default state read to separate function
           and use it in leds-gpio and leds-pwm

@Pavel I hope that it is okay to keep your acked-by on 2/3,
       the logic is the same but with switch, in favour of if

 .../devicetree/bindings/leds/leds-pwm.txt          |  2 +
 drivers/leds/led-core.c                            | 15 +++++++
 drivers/leds/leds-gpio.c                           | 12 +-----
 drivers/leds/leds-pwm.c                            | 49 +++++++++++++++++++---
 drivers/leds/leds.h                                |  1 +
 include/linux/leds.h                               | 12 ++++--
 6 files changed, 72 insertions(+), 19 deletions(-)

Message-Id: <20200713054259.7608-1-Denis.Osterland@diehl.com>
base-commit: 2742b4192a279c6ec72e55d5474c4c07756c7845




Diehl Connectivity Solutions GmbH
Geschäftsführung: Horst Leonberger
Sitz der Gesellschaft: Nürnberg - Registergericht: Amtsgericht
Nürnberg: HRB 32315
___________________________________________________________________________________________________

Der Inhalt der vorstehenden E-Mail ist nicht rechtlich bindend. Diese E-Mail enthaelt vertrauliche und/oder rechtlich geschuetzte Informationen.
Informieren Sie uns bitte, wenn Sie diese E-Mail faelschlicherweise erhalten haben. Bitte loeschen Sie in diesem Fall die Nachricht.
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The contents of the above mentioned e-mail is not legally binding. This e-mail contains confidential and/or legally protected information. Please inform us if you have received this e-mail by
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- For general information on data protection and your respective rights please visit https://www.diehl.com/group/en/transparency-and-information-obligations/

^ permalink raw reply	[flat|nested] 4+ messages in thread

* [PATCH v7 1/3] leds: move default_state read from fwnode to core
  2020-07-31 16:51 [PATCH v7 0/3] leds: pwm: add support for default-state device Denis Osterland-Heim
  2020-07-31 16:51 ` [PATCH v7 2/3] leds: pwm: add support for default-state device property Denis Osterland-Heim
  2020-07-31 16:51 ` [PATCH v7 3/3] leds: pwm: add reference to common leds for default-state Denis Osterland-Heim
@ 2020-07-31 16:51 ` Denis Osterland-Heim
  2 siblings, 0 replies; 4+ messages in thread
From: Denis Osterland-Heim @ 2020-07-31 16:51 UTC (permalink / raw)
  To: dmurphy, pavel, jacek.anaszewski
  Cc: linux-kernel, Denis Osterland-Heim, linux-leds, robh+dt, devicetree

This patch introduces a new function to read initial
default_state from fwnode.

Signed-off-by: Denis Osterland-Heim <Denis.Osterland@diehl.com>
---
 drivers/leds/led-core.c  | 15 +++++++++++++++
 drivers/leds/leds-gpio.c | 12 ++----------
 drivers/leds/leds.h      |  1 +
 include/linux/leds.h     | 12 +++++++++---
 4 files changed, 27 insertions(+), 13 deletions(-)

diff --git a/drivers/leds/led-core.c b/drivers/leds/led-core.c
index 846248a0693d..0ef220c154e4 100644
--- a/drivers/leds/led-core.c
+++ b/drivers/leds/led-core.c
@@ -478,3 +478,18 @@ int led_compose_name(struct device *dev, struct led_init_data *init_data,
 	return 0;
 }
 EXPORT_SYMBOL_GPL(led_compose_name);
+
+enum led_default_state led_init_default_state_get(struct fwnode_handle *fwnode)
+{
+	const char *state = NULL;
+
+	if (!fwnode_property_read_string(fwnode, "default-state", &state)) {
+		if (!strcmp(state, "keep"))
+			return LEDS_DEFSTATE_KEEP;
+		if (!strcmp(state, "on"))
+			return LEDS_DEFSTATE_ON;
+	}
+
+	return LEDS_DEFSTATE_OFF;
+}
+EXPORT_SYMBOL_GPL(led_init_default_state_get);
diff --git a/drivers/leds/leds-gpio.c b/drivers/leds/leds-gpio.c
index cf84096d88ce..564a7f497ac0 100644
--- a/drivers/leds/leds-gpio.c
+++ b/drivers/leds/leds-gpio.c
@@ -16,6 +16,7 @@
 #include <linux/platform_device.h>
 #include <linux/property.h>
 #include <linux/slab.h>
+#include "leds.h"
 
 struct gpio_led_data {
 	struct led_classdev cdev;
@@ -143,7 +144,6 @@ static struct gpio_leds_priv *gpio_leds_create(struct platform_device *pdev)
 	device_for_each_child_node(dev, child) {
 		struct gpio_led_data *led_dat = &priv->leds[priv->num_leds];
 		struct gpio_led led = {};
-		const char *state = NULL;
 
 		/*
 		 * Acquire gpiod from DT with uninitialized label, which
@@ -163,15 +163,7 @@ static struct gpio_leds_priv *gpio_leds_create(struct platform_device *pdev)
 		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;
-		}
+		led.default_state = led_init_default_state_get(child);
 
 		if (fwnode_property_present(child, "retain-state-suspended"))
 			led.retain_state_suspended = 1;
diff --git a/drivers/leds/leds.h b/drivers/leds/leds.h
index 2d9eb48bbed9..73451f64e916 100644
--- a/drivers/leds/leds.h
+++ b/drivers/leds/leds.h
@@ -29,6 +29,7 @@ ssize_t led_trigger_read(struct file *filp, struct kobject *kobj,
 ssize_t led_trigger_write(struct file *filp, struct kobject *kobj,
 			struct bin_attribute *bin_attr, char *buf,
 			loff_t pos, size_t count);
+enum led_default_state led_init_default_state_get(struct fwnode_handle *fwnode);
 
 extern struct rw_semaphore leds_list_lock;
 extern struct list_head leds_list;
diff --git a/include/linux/leds.h b/include/linux/leds.h
index 6a8d6409c993..db16c3ebc6b4 100644
--- a/include/linux/leds.h
+++ b/include/linux/leds.h
@@ -33,6 +33,12 @@ enum led_brightness {
 	LED_FULL	= 255,
 };
 
+enum led_default_state {
+	LEDS_DEFSTATE_OFF	= 0,
+	LEDS_DEFSTATE_ON	= 1,
+	LEDS_DEFSTATE_KEEP	= 2,
+};
+
 struct led_init_data {
 	/* device fwnode handle */
 	struct fwnode_handle *fwnode;
@@ -522,9 +528,9 @@ struct gpio_led {
 	/* default_state should be one of LEDS_GPIO_DEFSTATE_(ON|OFF|KEEP) */
 	struct gpio_desc *gpiod;
 };
-#define LEDS_GPIO_DEFSTATE_OFF		0
-#define LEDS_GPIO_DEFSTATE_ON		1
-#define LEDS_GPIO_DEFSTATE_KEEP		2
+#define LEDS_GPIO_DEFSTATE_OFF		LEDS_DEFSTATE_OFF
+#define LEDS_GPIO_DEFSTATE_ON		LEDS_DEFSTATE_ON
+#define LEDS_GPIO_DEFSTATE_KEEP		LEDS_DEFSTATE_KEEP
 
 struct gpio_led_platform_data {
 	int 		num_leds;
-- 
2.28.0



Diehl Connectivity Solutions GmbH
Geschäftsführung: Horst Leonberger
Sitz der Gesellschaft: Nürnberg - Registergericht: Amtsgericht
Nürnberg: HRB 32315
___________________________________________________________________________________________________

Der Inhalt der vorstehenden E-Mail ist nicht rechtlich bindend. Diese E-Mail enthaelt vertrauliche und/oder rechtlich geschuetzte Informationen.
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The contents of the above mentioned e-mail is not legally binding. This e-mail contains confidential and/or legally protected information. Please inform us if you have received this e-mail by
mistake and delete it in such a case. Each unauthorized reproduction, disclosure, alteration, distribution and/or publication of this e-mail is strictly prohibited. 
- For general information on data protection and your respective rights please visit https://www.diehl.com/group/en/transparency-and-information-obligations/

^ permalink raw reply	[flat|nested] 4+ messages in thread

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2020-07-31 16:51 [PATCH v7 0/3] leds: pwm: add support for default-state device Denis Osterland-Heim
2020-07-31 16:51 ` [PATCH v7 2/3] leds: pwm: add support for default-state device property Denis Osterland-Heim
2020-07-31 16:51 ` [PATCH v7 3/3] leds: pwm: add reference to common leds for default-state Denis Osterland-Heim
2020-07-31 16:51 ` [PATCH v7 1/3] leds: move default_state read from fwnode to core Denis Osterland-Heim

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