Messages in this thread | | | Subject | Re: [PATCH 1/2] leds: Add control of the voltage/current regulator to the LED core | From | Jean-Jacques Hiblot <> | Date | Mon, 15 Jul 2019 11:01:29 +0200 |
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Hi Dan,
On 12/07/2019 20:49, Dan Murphy wrote: > JJ > > On 7/8/19 5:35 AM, Jean-Jacques Hiblot wrote: >> A LED is usually powered by a voltage/current regulator. Let the LED >> core > Let the LED core know >> about it. This allows the LED core to turn on or off the power supply >> as needed. > >> >> Signed-off-by: Jean-Jacques Hiblot <jjhiblot@ti.com> >> --- >> drivers/leds/led-class.c | 10 ++++++++ >> drivers/leds/led-core.c | 53 +++++++++++++++++++++++++++++++++++++--- >> include/linux/leds.h | 4 +++ >> 3 files changed, 64 insertions(+), 3 deletions(-) >> >> diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c >> index 4793e77808e2..e01b2d982564 100644 >> --- a/drivers/leds/led-class.c >> +++ b/drivers/leds/led-class.c >> @@ -17,6 +17,7 @@ >> #include <linux/slab.h> >> #include <linux/spinlock.h> >> #include <linux/timer.h> >> +#include <linux/regulator/consumer.h> > > What if you move this to leds.h so core and class can both include it. > > >> #include <uapi/linux/uleds.h> >> #include "leds.h" >> @@ -272,6 +273,15 @@ int of_led_classdev_register(struct device >> *parent, struct device_node *np, >> dev_warn(parent, "Led %s renamed to %s due to name collision", >> led_cdev->name, dev_name(led_cdev->dev)); >> + led_cdev->regulator = devm_regulator_get(led_cdev->dev, "power"); > > Is the regulator always going to be called power?
Actually in the dts, that will be "power-supply". I lacked the imagination to come up with a better name.
> >> + if (IS_ERR(led_cdev->regulator)) { >> + dev_err(led_cdev->dev, "Cannot get the power supply for %s\n", >> + led_cdev->name); >> + device_unregister(led_cdev->dev); >> + mutex_unlock(&led_cdev->led_access); >> + return PTR_ERR(led_cdev->regulator); > > This is listed as optional in the DT doc. This appears to be required.
The regulator core will provide a dummy regulator if none is given in the device tree. I would rather have an error in that case, but that is not how it works.
> > I prefer to keep it optional. Many LED drivers are connected to fixed > non-managed supplies. > >> + } >> + >> if (led_cdev->flags & LED_BRIGHT_HW_CHANGED) { >> ret = led_add_brightness_hw_changed(led_cdev); >> if (ret) { >> diff --git a/drivers/leds/led-core.c b/drivers/leds/led-core.c >> index 7107cd7e87cf..139de6b08cad 100644 >> --- a/drivers/leds/led-core.c >> +++ b/drivers/leds/led-core.c >> @@ -16,6 +16,7 @@ >> #include <linux/rwsem.h> >> #include <linux/slab.h> >> #include "leds.h" >> +#include <linux/regulator/consumer.h> >> DECLARE_RWSEM(leds_list_lock); >> EXPORT_SYMBOL_GPL(leds_list_lock); >> @@ -23,6 +24,31 @@ EXPORT_SYMBOL_GPL(leds_list_lock); >> LIST_HEAD(leds_list); >> EXPORT_SYMBOL_GPL(leds_list); >> +static bool __led_need_regulator_update(struct led_classdev >> *led_cdev, >> + int brightness) >> +{ >> + bool new_regulator_state = (brightness != LED_OFF); >> + >> + return led_cdev->regulator_state != new_regulator_state; >> +} >> + >> +static int __led_handle_regulator(struct led_classdev *led_cdev, >> + int brightness) >> +{ >> + if (__led_need_regulator_update(led_cdev, brightness)) { >> + int ret; > > Prefer to this to be moved up. ok > >> + >> + if (brightness != LED_OFF) >> + ret = regulator_enable(led_cdev->regulator); >> + else >> + ret = regulator_disable(led_cdev->regulator); >> + if (ret) >> + return ret; > new line >> + led_cdev->regulator_state = (brightness != LED_OFF); >> + } >> + return 0; >> +} >> + >> static int __led_set_brightness(struct led_classdev *led_cdev, >> enum led_brightness value) >> { >> @@ -80,6 +106,7 @@ static void led_timer_function(struct timer_list *t) >> } >> led_set_brightness_nosleep(led_cdev, brightness); >> + __led_handle_regulator(led_cdev, brightness); > > Again this seems to indicate that the regulator is a required property > for the LEDs > > This needs to be made optional. And the same comment through out for > every call. > > >> /* Return in next iteration if led is in one-shot mode and we >> are in >> * the final blink state so that the led is toggled each >> delay_on + >> @@ -115,6 +142,8 @@ static void set_brightness_delayed(struct >> work_struct *ws) >> if (ret == -ENOTSUPP) >> ret = __led_set_brightness_blocking(led_cdev, >> led_cdev->delayed_set_value); >> + __led_handle_regulator(led_cdev, led_cdev->delayed_set_value); >> + >> if (ret < 0 && >> /* LED HW might have been unplugged, therefore don't warn */ >> !(ret == -ENODEV && (led_cdev->flags & LED_UNREGISTERING) && >> @@ -141,6 +170,7 @@ static void led_set_software_blink(struct >> led_classdev *led_cdev, >> /* never on - just set to off */ >> if (!delay_on) { >> led_set_brightness_nosleep(led_cdev, LED_OFF); >> + __led_handle_regulator(led_cdev, LED_OFF); >> return; >> } >> @@ -148,6 +178,7 @@ static void led_set_software_blink(struct >> led_classdev *led_cdev, >> if (!delay_off) { >> led_set_brightness_nosleep(led_cdev, >> led_cdev->blink_brightness); >> + __led_handle_regulator(led_cdev, led_cdev->blink_brightness); >> return; >> } >> @@ -256,8 +287,14 @@ void led_set_brightness_nopm(struct >> led_classdev *led_cdev, >> enum led_brightness value) >> { >> /* Use brightness_set op if available, it is guaranteed not to >> sleep */ >> - if (!__led_set_brightness(led_cdev, value)) >> - return; >> + if (!__led_set_brightness(led_cdev, value)) { >> + /* >> + * if regulator state doesn't need to be changed, that is all/ >> + * Otherwise delegate the change to a work queue >> + */ >> + if (!__led_need_regulator_update(led_cdev, value)) >> + return; >> + } >> /* If brightness setting can sleep, delegate it to a work >> queue task */ >> led_cdev->delayed_set_value = value; >> @@ -280,6 +317,8 @@ EXPORT_SYMBOL_GPL(led_set_brightness_nosleep); >> int led_set_brightness_sync(struct led_classdev *led_cdev, >> enum led_brightness value) >> { >> + int ret; >> + >> if (led_cdev->blink_delay_on || led_cdev->blink_delay_off) >> return -EBUSY; >> @@ -288,7 +327,15 @@ int led_set_brightness_sync(struct >> led_classdev *led_cdev, >> if (led_cdev->flags & LED_SUSPENDED) >> return 0; >> - return __led_set_brightness_blocking(led_cdev, >> led_cdev->brightness); >> + ret = __led_set_brightness_blocking(led_cdev, >> led_cdev->brightness); >> + if (ret) >> + return ret; >> + >> + ret = __led_handle_regulator(led_cdev, led_cdev->brightness); > > Can't you just return here?
ok
thanks for the review
JJ
> > Dan > >> + if (ret) >> + return ret; >> + >> + return 0; >> } >> EXPORT_SYMBOL_GPL(led_set_brightness_sync); >> diff --git a/include/linux/leds.h b/include/linux/leds.h >> index 9b2bf574a17a..bee8e3f8dddd 100644 >> --- a/include/linux/leds.h >> +++ b/include/linux/leds.h >> @@ -123,6 +123,10 @@ struct led_classdev { >> /* Ensures consistent access to the LED Flash Class device */ >> struct mutex led_access; >> + >> + /* regulator */ >> + struct regulator *regulator; >> + bool regulator_state; >> }; >> extern int of_led_classdev_register(struct device *parent,
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