From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matt Ranostay Subject: [PATCH v5] leds: pca963x: enable low-power state Date: Fri, 28 Oct 2016 18:20:42 -0700 Message-ID: <1477704042-6598-1-git-send-email-matt@ranostay.consulting> Return-path: Received: from mail-pf0-f195.google.com ([209.85.192.195]:33821 "EHLO mail-pf0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935196AbcJ2BU6 (ORCPT ); Fri, 28 Oct 2016 21:20:58 -0400 Received: by mail-pf0-f195.google.com with SMTP id u84so2574760pfj.1 for ; Fri, 28 Oct 2016 18:20:58 -0700 (PDT) Sender: linux-leds-owner@vger.kernel.org List-Id: linux-leds@vger.kernel.org To: linux-leds@vger.kernel.org Cc: Matt Ranostay , Peter Meerwald , Ricardo Ribalda , Tony Lindgren , Jacek Anaszewski Allow chip to enter low power state when no LEDs are being lit or in blink mode. Cc: Peter Meerwald , Cc: Ricardo Ribalda Cc: Tony Lindgren Cc: Jacek Anaszewski Signed-off-by: Matt Ranostay --- Changes from v1: * remove runtime pm * count leds that are off, if all then enter low-power state Changes from v2: * add reference count of leds to reduce i2c transactions Changes from v3: * switch to checking bitmask to reduce i2c transactions Changes from v4: * mutex lock during power mangement routine * simplify the led bitmask check 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) */ -- 2.7.4