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().
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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