* [PATCH] leds: leds-pca963x: add power management support
@ 2016-09-30 19:27 Matt Ranostay
2016-09-30 21:23 ` Jacek Anaszewski
0 siblings, 1 reply; 3+ messages in thread
From: Matt Ranostay @ 2016-09-30 19:27 UTC (permalink / raw)
To: linux-kernel, linux-leds
Cc: Matt Ranostay, Tony Lindgren, Richard Purdie, Jacek Anaszewski
Turn off LEDS on suspend and put device in low power state, and restore
settings on resume.
Cc: Tony Lindgren <tony@atomide.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Jacek Anaszewski <j.anaszewski@samsung.com>
Signed-off-by: Matt Ranostay <matt@ranostay.consulting>
---
drivers/leds/leds-pca963x.c | 31 +++++++++++++++++++++++++++++++
1 file changed, 31 insertions(+)
diff --git a/drivers/leds/leds-pca963x.c b/drivers/leds/leds-pca963x.c
index 407eba11e187..4840bdaa1b48 100644
--- a/drivers/leds/leds-pca963x.c
+++ b/drivers/leds/leds-pca963x.c
@@ -382,6 +382,7 @@ static int pca963x_probe(struct i2c_client *client,
pca963x[i].led_cdev.name = pca963x[i].name;
pca963x[i].led_cdev.brightness_set_blocking = pca963x_led_set;
+ pca963x[i].led_cdev.flags = LED_CORE_SUSPENDRESUME;
if (pdata && pdata->blink_type == PCA963X_HW_BLINK)
pca963x[i].led_cdev.blink_set = pca963x_blink_set;
@@ -422,10 +423,40 @@ static int pca963x_remove(struct i2c_client *client)
return 0;
}
+static int pca963x_set_power(struct i2c_client *client, bool state)
+{
+ return i2c_smbus_write_byte_data(client, PCA963X_MODE1,
+ state ? 0 : BIT(4));
+}
+
+static int pca963x_suspend(struct device *dev)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+
+ return pca963x_set_power(client, false);
+}
+
+static int pca963x_resume(struct device *dev)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ int ret;
+
+ ret = pca963x_set_power(client, true);
+
+ /* wait for oscillator enabling */
+ if (!ret)
+ usleep_range(500, 1000);
+
+ return ret;
+}
+
+static SIMPLE_DEV_PM_OPS(pca963x_pm, pca963x_suspend, pca963x_resume);
+
static struct i2c_driver pca963x_driver = {
.driver = {
.name = "leds-pca963x",
.of_match_table = of_match_ptr(of_pca963x_match),
+ .pm = &pca963x_pm,
},
.probe = pca963x_probe,
.remove = pca963x_remove,
--
2.7.4
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH] leds: leds-pca963x: add power management support
2016-09-30 19:27 [PATCH] leds: leds-pca963x: add power management support Matt Ranostay
@ 2016-09-30 21:23 ` Jacek Anaszewski
2016-09-30 22:57 ` Matt Ranostay
0 siblings, 1 reply; 3+ messages in thread
From: Jacek Anaszewski @ 2016-09-30 21:23 UTC (permalink / raw)
To: Matt Ranostay, linux-kernel, linux-leds
Cc: Matt Ranostay, Tony Lindgren, Richard Purdie, Jacek Anaszewski
Hi Matt,
Thanks for the patch.
On 09/30/2016 09:27 PM, Matt Ranostay wrote:
> Turn off LEDS on suspend and put device in low power state, and restore
> settings on resume.
>
> Cc: Tony Lindgren <tony@atomide.com>
> Cc: Richard Purdie <rpurdie@rpsys.net>
> Cc: Jacek Anaszewski <j.anaszewski@samsung.com>
> Signed-off-by: Matt Ranostay <matt@ranostay.consulting>
> ---
> drivers/leds/leds-pca963x.c | 31 +++++++++++++++++++++++++++++++
> 1 file changed, 31 insertions(+)
>
> diff --git a/drivers/leds/leds-pca963x.c b/drivers/leds/leds-pca963x.c
> index 407eba11e187..4840bdaa1b48 100644
> --- a/drivers/leds/leds-pca963x.c
> +++ b/drivers/leds/leds-pca963x.c
> @@ -382,6 +382,7 @@ static int pca963x_probe(struct i2c_client *client,
>
> pca963x[i].led_cdev.name = pca963x[i].name;
> pca963x[i].led_cdev.brightness_set_blocking = pca963x_led_set;
> + pca963x[i].led_cdev.flags = LED_CORE_SUSPENDRESUME;
>
> if (pdata && pdata->blink_type == PCA963X_HW_BLINK)
> pca963x[i].led_cdev.blink_set = pca963x_blink_set;
> @@ -422,10 +423,40 @@ static int pca963x_remove(struct i2c_client *client)
> return 0;
> }
>
> +static int pca963x_set_power(struct i2c_client *client, bool state)
> +{
> + return i2c_smbus_write_byte_data(client, PCA963X_MODE1,
> + state ? 0 : BIT(4));
> +}
> +
> +static int pca963x_suspend(struct device *dev)
> +{
> + struct i2c_client *client = to_i2c_client(dev);
> +
> + return pca963x_set_power(client, false);
> +}
> +
> +static int pca963x_resume(struct device *dev)
> +{
> + struct i2c_client *client = to_i2c_client(dev);
> + int ret;
> +
> + ret = pca963x_set_power(client, true);
> +
> + /* wait for oscillator enabling */
> + if (!ret)
> + usleep_range(500, 1000);
> +
> + return ret;
> +}
> +
> +static SIMPLE_DEV_PM_OPS(pca963x_pm, pca963x_suspend, pca963x_resume);
> +
> static struct i2c_driver pca963x_driver = {
> .driver = {
> .name = "leds-pca963x",
> .of_match_table = of_match_ptr(of_pca963x_match),
> + .pm = &pca963x_pm,
pm ops are initialized in led-class.c. If LED_CORE_SUSPENDRESUME
flag is set by a LED class driver, then the brightness will be
set to 0 on suspend and brought back on resume.
LED class driver's responsibility is to enter power down mode if
all LED class devices it exposes have their brightness set to 0.
Effectively, you should avoid defining pm ops, but instead
just track how many LEDs are on, and set the device in the power
down mode if brightness of the last active LED is set to LED_OFF.
Similarly the device should be powered up if any of LEDs brightness
is set to a value greater than 0.
> },
> .probe = pca963x_probe,
> .remove = pca963x_remove,
>
--
Best regards,
Jacek Anaszewski
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH] leds: leds-pca963x: add power management support
2016-09-30 21:23 ` Jacek Anaszewski
@ 2016-09-30 22:57 ` Matt Ranostay
0 siblings, 0 replies; 3+ messages in thread
From: Matt Ranostay @ 2016-09-30 22:57 UTC (permalink / raw)
To: Jacek Anaszewski
Cc: linux-kernel, linux-leds, Matt Ranostay, Tony Lindgren,
Richard Purdie, Jacek Anaszewski, Liam Breck
On Fri, Sep 30, 2016 at 2:23 PM, Jacek Anaszewski
<jacek.anaszewski@gmail.com> wrote:
> Hi Matt,
>
> Thanks for the patch.
>
>
> On 09/30/2016 09:27 PM, Matt Ranostay wrote:
>>
>> Turn off LEDS on suspend and put device in low power state, and restore
>> settings on resume.
>>
>> Cc: Tony Lindgren <tony@atomide.com>
>> Cc: Richard Purdie <rpurdie@rpsys.net>
>> Cc: Jacek Anaszewski <j.anaszewski@samsung.com>
>> Signed-off-by: Matt Ranostay <matt@ranostay.consulting>
>> ---
>> drivers/leds/leds-pca963x.c | 31 +++++++++++++++++++++++++++++++
>> 1 file changed, 31 insertions(+)
>>
>> diff --git a/drivers/leds/leds-pca963x.c b/drivers/leds/leds-pca963x.c
>> index 407eba11e187..4840bdaa1b48 100644
>> --- a/drivers/leds/leds-pca963x.c
>> +++ b/drivers/leds/leds-pca963x.c
>> @@ -382,6 +382,7 @@ static int pca963x_probe(struct i2c_client *client,
>>
>> pca963x[i].led_cdev.name = pca963x[i].name;
>> pca963x[i].led_cdev.brightness_set_blocking =
>> pca963x_led_set;
>> + pca963x[i].led_cdev.flags = LED_CORE_SUSPENDRESUME;
>>
>> if (pdata && pdata->blink_type == PCA963X_HW_BLINK)
>> pca963x[i].led_cdev.blink_set = pca963x_blink_set;
>> @@ -422,10 +423,40 @@ static int pca963x_remove(struct i2c_client *client)
>> return 0;
>> }
>>
>> +static int pca963x_set_power(struct i2c_client *client, bool state)
>> +{
>> + return i2c_smbus_write_byte_data(client, PCA963X_MODE1,
>> + state ? 0 : BIT(4));
>> +}
>> +
>> +static int pca963x_suspend(struct device *dev)
>> +{
>> + struct i2c_client *client = to_i2c_client(dev);
>> +
>> + return pca963x_set_power(client, false);
>> +}
>> +
>> +static int pca963x_resume(struct device *dev)
>> +{
>> + struct i2c_client *client = to_i2c_client(dev);
>> + int ret;
>> +
>> + ret = pca963x_set_power(client, true);
>> +
>> + /* wait for oscillator enabling */
>> + if (!ret)
>> + usleep_range(500, 1000);
>> +
>> + return ret;
>> +}
>> +
>> +static SIMPLE_DEV_PM_OPS(pca963x_pm, pca963x_suspend, pca963x_resume);
>> +
>> static struct i2c_driver pca963x_driver = {
>> .driver = {
>> .name = "leds-pca963x",
>> .of_match_table = of_match_ptr(of_pca963x_match),
>> + .pm = &pca963x_pm,
>
>
> pm ops are initialized in led-class.c. If LED_CORE_SUSPENDRESUME
> flag is set by a LED class driver, then the brightness will be
> set to 0 on suspend and brought back on resume.
Understood.
>
> LED class driver's responsibility is to enter power down mode if
> all LED class devices it exposes have their brightness set to 0.
>
> Effectively, you should avoid defining pm ops, but instead
> just track how many LEDs are on, and set the device in the power
> down mode if brightness of the last active LED is set to LED_OFF.
> Similarly the device should be powered up if any of LEDs brightness
> is set to a value greater than 0.
Ok in this case it would make sense to use runtime PM.. which
shouldn't be too hard to do. Will fix in v2
>
>> },
>> .probe = pca963x_probe,
>> .remove = pca963x_remove,
>>
>
> --
> Best regards,
> Jacek Anaszewski
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2016-09-30 22:58 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2016-09-30 19:27 [PATCH] leds: leds-pca963x: add power management support Matt Ranostay
2016-09-30 21:23 ` Jacek Anaszewski
2016-09-30 22:57 ` Matt Ranostay
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