diff --git a/drivers/media/platform/soc_camera/soc_camera.c b/drivers/media/platform/soc_camera/soc_camera.c index e201d48de70e..4b8c024fc487 100644 --- a/drivers/media/platform/soc_camera/soc_camera.c +++ b/drivers/media/platform/soc_camera/soc_camera.c @@ -71,11 +71,21 @@ static int video_dev_create(struct soc_camera_device *icd); int soc_camera_power_on(struct device *dev, struct soc_camera_subdev_desc *ssdd, struct v4l2_clk *clk) { - int ret = clk ? v4l2_clk_enable(clk) : 0; - if (ret < 0) { - dev_err(dev, "Cannot enable clock: %d\n", ret); - return ret; + int ret; + bool clock_toggle; + + if (clk && (!ssdd->unbalanced_power || + !test_and_set_bit(0, &ssdd->clock_state))) { + ret = v4l2_clk_enable(clk); + if (ret < 0) { + dev_err(dev, "Cannot enable clock: %d\n", ret); + return ret; + } + clock_toggle = true; + } else { + clock_toggle = false; } + ret = regulator_bulk_enable(ssdd->sd_pdata.num_regulators, ssdd->sd_pdata.regulators); if (ret < 0) { @@ -98,7 +108,7 @@ epwron: regulator_bulk_disable(ssdd->sd_pdata.num_regulators, ssdd->sd_pdata.regulators); eregenable: - if (clk) + if (clock_toggle) v4l2_clk_disable(clk); return ret; @@ -127,7 +137,7 @@ int soc_camera_power_off(struct device *dev, struct soc_camera_subdev_desc *ssdd ret = ret ? : err; } - if (clk) + if (clk && (!ssdd->unbalanced_power || test_and_clear_bit(0, &ssdd->clock_state))) v4l2_clk_disable(clk); return ret; diff --git a/include/media/soc_camera.h b/include/media/soc_camera.h index 2bb418346b1f..865246b00127 100644 --- a/include/media/soc_camera.h +++ b/include/media/soc_camera.h @@ -146,6 +146,15 @@ struct soc_camera_subdev_desc { /* sensor driver private platform data */ void *drv_priv; + /* + * Set unbalanced_power to true to deal with legacy drivers, failing to + * balance their calls to subdevice's .s_power() method. clock_state is + * then used internally by helper functions, it shouldn't be touched by + * drivers or the platform code. + */ + bool unbalanced_power; + unsigned long clock_state; + /* Optional callbacks to power on or off and reset the sensor */ int (*power)(struct device *, int); int (*reset)(struct device *); @@ -201,6 +210,11 @@ struct soc_camera_link { void *priv; + /* Set by platforms to handle misbehaving drivers */ + bool unbalanced_power; + /* Used by soc-camera helper functions */ + unsigned long clock_state; + /* Optional callbacks to power on or off and reset the sensor */ int (*power)(struct device *, int); int (*reset)(struct device *);