On Thu, Oct 27, 2016 at 2:13 AM, Jacek Anaszewski
<j.anaszewski@xxxxxxxxxxx> wrote:
> On 10/27/2016 06:04 AM, Matt Ranostay wrote:
>>
>> Allow chip to enter low power state when no LEDs are being lit or in
>> blink mode.
>>
>> Cc: Peter Meerwald <p.meerwald@xxxxxxxxxxxxxxxxxx>,
>> Cc: Ricardo Ribalda <ricardo.ribalda@xxxxxxxxx>
>> Cc: Tony Lindgren <tony@xxxxxxxxxxx>
>> Cc: Jacek Anaszewski <j.anaszewski@xxxxxxxxxxx>
>> Signed-off-by: Matt Ranostay <matt@ranostay.consulting>
>> ---
>> drivers/leds/leds-pca963x.c | 33 ++++++++++++++++++++++++++++++---
>> 1 file changed, 30 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/leds/leds-pca963x.c b/drivers/leds/leds-pca963x.c
>> index b6ce1f2ec33e..e1767369776f 100644
>> --- a/drivers/leds/leds-pca963x.c
>> +++ b/drivers/leds/leds-pca963x.c
>> @@ -103,6 +103,7 @@ struct pca963x {
>> struct mutex mutex;
>> struct i2c_client *client;
>> struct pca963x_led *leds;
>> + int leds_on;
>> };
>>
>> struct pca963x_led {
>> @@ -180,14 +181,40 @@ static void pca963x_blink(struct pca963x_led
>> *pca963x)
>> mutex_unlock(&pca963x->chip->mutex);
>> }
>>
>> +static int pca963x_power_state(struct pca963x_led *pca963x)
>> +{
>> + int i, ret = 0, leds_on = 0;
>> + int prev_leds = pca963x->chip->leds_on;
>> +
>> + for (i = 0; i < pca963x->chip->chipdef->n_leds; i++) {
>> + if (pca963x->chip->leds[i].led_cdev.brightness > 0)
>> + leds_on++;
>> + }
>
>
> You're still executing this loop on every brightness setting.
> It could be avoided if you cached current LED states in struct pca963x
> using bit flags and set_bit()/clear_bit().
Gah should have thought of that... fixing in v4..
>
> In pca963x_led_set() you would have to set bit related to
> pca963x->led_num if brightness > 0 and clear it otherwise.
>
> Then, you would have to check if any bit is on with a single
> readout, and update the power mode basing on that if needed.
>
>
>> +
>> + if (leds_on != prev_leds && !(leds_on && prev_leds)) {
>> + ret = i2c_smbus_write_byte_data(pca963x->chip->client,
>> + PCA963X_MODE1,
>> + leds_on ? 0 : BIT(4));
>> + }
>> +
>> + pca963x->chip->leds_on = leds_on;
>> +
>> + return ret;
>> +}
>> +
>> static int pca963x_led_set(struct led_classdev *led_cdev,
>> enum led_brightness value)
>> {
>> struct pca963x_led *pca963x;
>> + int ret;
>>
>> pca963x = container_of(led_cdev, struct pca963x_led, led_cdev);
>>
>> - return pca963x_brightness(pca963x, value);
>> + ret = pca963x_brightness(pca963x, value);
>> + if (ret < 0)
>> + return ret;
>> +
>> + return pca963x_power_state(pca963x);
>> }
>>
>> static unsigned int pca963x_period_scale(struct pca963x_led *pca963x,
>> @@ -403,8 +430,8 @@ static int pca963x_probe(struct i2c_client *client,
>> goto exit;
>> }
>>
>> - /* Disable LED all-call address and set normal mode */
>> - i2c_smbus_write_byte_data(client, PCA963X_MODE1, 0x00);
>> + /* Disable LED all-call address, and power down initially */
>> + i2c_smbus_write_byte_data(client, PCA963X_MODE1, BIT(4));
>>
>> if (pdata) {
>> /* Configure output: open-drain or totem pole (push-pull)
>> */
>>
>
>
> --
> Best regards,
> Jacek Anaszewski
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