From a8c170b015ff6695641bdfbdb74729411ba1e9e5 Mon Sep 17 00:00:00 2001
From: Matt Ranostay <mranostay@gmail.com>
Date: Fri, 28 Oct 2016 18:20:42 -0700
Subject: [PATCH] leds: pca963x: enable low-power state
Allow chip to enter low power state when no LEDs are being lit or in
blink mode.
Cc: Peter Meerwald <p.meerwald@bct-electronic.com>,
Cc: Ricardo Ribalda <ricardo.ribalda@gmail.com>
Cc: Tony Lindgren <tony@atomide.com>
Signed-off-by: Matt Ranostay <matt@ranostay.consulting>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
---
drivers/leds/leds-pca963x.c | 40 ++++++++++++++++++++++++++++++-------
1 file changed, 33 insertions(+), 7 deletions(-)
diff --git a/drivers/leds/leds-pca963x.c b/drivers/leds/leds-pca963x.c
index b6ce1f2ec33e..46fbf935944a 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;
+ unsigned long leds_on;
};
struct pca963x_led {
@@ -124,7 +125,6 @@ static int pca963x_brightness(struct pca963x_led *pca963x,
u8 mask = 0x3 << shift;
int ret;
- mutex_lock(&pca963x->chip->mutex);
ledout = i2c_smbus_read_byte_data(pca963x->chip->client, ledout_addr);
switch (brightness) {
case LED_FULL:
@@ -141,14 +141,13 @@ static int pca963x_brightness(struct pca963x_led *pca963x,
PCA963X_PWM_BASE + pca963x->led_num,
brightness);
if (ret < 0)
- goto unlock;
+ return ret;
ret = i2c_smbus_write_byte_data(pca963x->chip->client,
ledout_addr,
(ledout & ~mask) | (PCA963X_LED_PWM << shift));
break;
}
-unlock:
- mutex_unlock(&pca963x->chip->mutex);
+
return ret;
}
@@ -180,14 +179,41 @@ static void pca963x_blink(struct pca963x_led *pca963x)
mutex_unlock(&pca963x->chip->mutex);
}
+static int pca963x_power_state(struct pca963x_led *pca963x)
+{
+ unsigned long *leds_on = &pca963x->chip->leds_on;
+ unsigned long cached_leds = pca963x->chip->leds_on;
+
+ if (pca963x->led_cdev.brightness)
+ set_bit(pca963x->led_num, leds_on);
+ else
+ clear_bit(pca963x->led_num, leds_on);
+
+ if (!(*leds_on) != !cached_leds)
+ return i2c_smbus_write_byte_data(pca963x->chip->client,
+ PCA963X_MODE1, *leds_on ? 0 : BIT(4));
+
+ return 0;
+}
+
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);
+ mutex_lock(&pca963x->chip->mutex);
+
+ ret = pca963x_brightness(pca963x, value);
+ if (ret < 0)
+ goto unlock;
+ ret = pca963x_power_state(pca963x);
+
+unlock:
+ mutex_unlock(&pca963x->chip->mutex);
+ return ret;
}
static unsigned int pca963x_period_scale(struct pca963x_led *pca963x,
@@ -403,8 +429,8 @@ 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) */
--
2.30.9