| Message ID | 1350637589-7405-3-git-send-email-acourbot@nvidia.com |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
On Fri, 2012-10-19 at 18:06 +0900, Alexandre Courbot wrote: > Make use of the power sequences specified in the device tree or platform > data to control how the backlight is powered on and off. > > Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> > --- > .../bindings/video/backlight/pwm-backlight.txt | 72 ++++++++- > drivers/video/backlight/Kconfig | 1 + > drivers/video/backlight/pwm_bl.c | 161 ++++++++++++++++----- > include/linux/pwm_backlight.h | 18 ++- > 4 files changed, 213 insertions(+), 39 deletions(-) > > diff --git a/Documentation/devicetree/bindings/video/backlight/pwm-backlight.txt b/Documentation/devicetree/bindings/video/backlight/pwm-backlight.txt > index 1e4fc72..3ba25ea 100644 > --- a/Documentation/devicetree/bindings/video/backlight/pwm-backlight.txt > +++ b/Documentation/devicetree/bindings/video/backlight/pwm-backlight.txt > @@ -14,15 +14,83 @@ Required properties: > Optional properties: > - pwm-names: a list of names for the PWM devices specified in the > "pwms" property (see PWM binding[0]) > + - low-threshold-brightness: brightness threshold low level. Sets the lowest > + brightness value. > + On some panels the backlight misbehaves if the duty cycle percentage of the > + PWM wave is less than a certain level (say 20%). In this example the user > + can set low-threshold-brightness to a value above 50 (ie, 20% of 255), thus > + preventing the PWM duty cycle from going too low. > + On setting low-threshold-brightness the range of brightness levels is > + calculated in the range low-threshold-brightness to the maximum value in > + brightness-levels, described above. > + - pwm-names: name for the PWM device specified in the "pwms" property (see PWM > + binding[0]). Necessary if power sequences are used > + - power-sequences: Power sequences (see Power sequences[1]) used to bring the > + backlight on and off. If this property is present, then two power > + sequences named "power-on" and "power-off" must be defined to control how > + the backlight is to be powered on and off. These sequences must reference > + the PWM specified in the pwms property by its name, and can also reference > + other resources supported by the power sequences mechanism > > [0]: Documentation/devicetree/bindings/pwm/pwm.txt > +[1]: Documentation/devicetree/bindings/power/power_seq.txt > > Example: > > backlight { > compatible = "pwm-backlight"; > - pwms = <&pwm 0 5000000>; > - > brightness-levels = <0 4 8 16 32 64 128 255>; > default-brightness-level = <6>; > + low-threshold-brightness = <50>; > + > + /* resources used by the power sequences */ > + pwms = <&pwm 0 5000000>; > + pwm-names = "backlight"; > + power-supply = <&backlight_reg>; > + > + power-sequences { > + power-on { > + step0 { > + type = "regulator"; > + id = "power"; > + enable; > + }; > + step1 { > + type = "delay"; > + delay = <10000>; > + }; > + step2 { > + type = "pwm"; > + id = "backlight"; > + enable; > + }; > + step3 { > + type = "gpio"; > + gpio = <&gpio 28 0>; > + value = <1>; > + }; > + }; > + > + power-off { > + step0 { > + type = "gpio"; > + gpio = <&gpio 28 0>; > + value = <0>; > + }; > + step1 { > + type = "pwm"; > + id = "backlight"; > + disable; > + }; > + step2 { > + type = "delay"; > + delay = <10000>; > + }; > + step3 { > + type = "regulator"; > + id = "power"; > + disable; > + }; > + }; > + }; > }; > diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig > index c101697..c2e5f79 100644 > --- a/drivers/video/backlight/Kconfig > +++ b/drivers/video/backlight/Kconfig > @@ -239,6 +239,7 @@ config BACKLIGHT_CARILLO_RANCH > config BACKLIGHT_PWM > tristate "Generic PWM based Backlight Driver" > depends on PWM > + select POWER_SEQ > help > If you have a LCD backlight adjustable by PWM, say Y to enable > this driver. > diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c > index 069983c..e607c6e 100644 > --- a/drivers/video/backlight/pwm_bl.c > +++ b/drivers/video/backlight/pwm_bl.c > @@ -27,6 +27,12 @@ struct pwm_bl_data { > unsigned int period; > unsigned int lth_brightness; > unsigned int *levels; > + bool enabled; > + struct power_seq_set power_seqs; > + struct power_seq *power_on_seq; > + struct power_seq *power_off_seq; > + > + /* Legacy callbacks */ > int (*notify)(struct device *, > int brightness); > void (*notify_after)(struct device *, > @@ -35,6 +41,52 @@ struct pwm_bl_data { > void (*exit)(struct device *); > }; > > +static void pwm_backlight_on(struct backlight_device *bl) > +{ > + struct pwm_bl_data *pb = dev_get_drvdata(&bl->dev); > + int ret; > + > + if (pb->enabled) > + return; > + > + if (pb->power_on_seq) { > + ret = power_seq_run(pb->power_on_seq); > + if (ret < 0) { > + dev_err(&bl->dev, "cannot run power on sequence\n"); > + return; > + } > + } else { > + /* legacy framework */ > + pwm_config(pb->pwm, 0, pb->period); > + pwm_disable(pb->pwm); Is this right? pwm_disable() in the backlight_on function? > + } > + > + pb->enabled = true; > +} > + > +static void pwm_backlight_off(struct backlight_device *bl) > +{ > + struct pwm_bl_data *pb = dev_get_drvdata(&bl->dev); > + int ret; > + > + if (!pb->enabled) > + return; > + > + if (pb->power_off_seq) { > + ret = power_seq_run(pb->power_off_seq); > + if (ret < 0) { > + dev_err(&bl->dev, "cannot run power off sequence\n"); > + return; > + } > + } else { > + /* legacy framework */ > + pwm_enable(pb->pwm); Same here.. owm_enable() in backlight_off() > + return; > + } > + > + pb->enabled = false; > +} > + > static int pwm_backlight_update_status(struct backlight_device *bl) > { > struct pwm_bl_data *pb = dev_get_drvdata(&bl->dev); > @@ -51,8 +103,7 @@ static int pwm_backlight_update_status(struct backlight_device *bl) > brightness = pb->notify(pb->dev, brightness); > > if (brightness == 0) { > - pwm_config(pb->pwm, 0, pb->period); > - pwm_disable(pb->pwm); > + pwm_backlight_off(bl); > } else { > int duty_cycle; > > @@ -66,7 +117,7 @@ static int pwm_backlight_update_status(struct backlight_device *bl) > duty_cycle = pb->lth_brightness + > (duty_cycle * (pb->period - pb->lth_brightness) / max); > pwm_config(pb->pwm, duty_cycle, pb->period); > - pwm_enable(pb->pwm); > + pwm_backlight_on(bl); > } > > if (pb->notify_after) > @@ -145,11 +196,10 @@ static int pwm_backlight_parse_dt(struct device *dev, > data->max_brightness--; > } > > - /* > - * TODO: Most users of this driver use a number of GPIOs to control > - * backlight power. Support for specifying these needs to be > - * added. > - */ > + /* read power sequences */ > + data->power_seqs = devm_of_parse_power_seq_set(dev); > + if (IS_ERR(data->power_seqs)) > + return PTR_ERR(data->power_seqs); > > return 0; > } > @@ -172,6 +222,7 @@ static int pwm_backlight_probe(struct platform_device *pdev) > { > struct platform_pwm_backlight_data *data = pdev->dev.platform_data; > struct platform_pwm_backlight_data defdata; > + struct power_seq_resource *res; > struct backlight_properties props; > struct backlight_device *bl; > struct pwm_bl_data *pb; > @@ -180,7 +231,9 @@ static int pwm_backlight_probe(struct platform_device *pdev) > > if (!data) { > ret = pwm_backlight_parse_dt(&pdev->dev, &defdata); > - if (ret < 0) { > + if (ret == -EPROBE_DEFER) { > + return ret; > + } else if (ret < 0) { > dev_err(&pdev->dev, "failed to find platform data\n"); > return ret; > } > @@ -201,6 +254,68 @@ static int pwm_backlight_probe(struct platform_device *pdev) > goto err_alloc; > } > > + if (data->power_seqs) { > + /* use power sequences */ > + struct power_seq_set *seqs = &pb->power_seqs; > + > + power_seq_set_init(seqs, &pdev->dev); > + power_seq_set_add_sequences(seqs, data->power_seqs); > + > + /* Check that the required sequences are here */ > + pb->power_on_seq = power_seq_lookup(seqs, "power-on"); > + if (!pb->power_on_seq) { > + dev_err(&pdev->dev, "missing power-on sequence\n"); > + return -EINVAL; > + } > + pb->power_off_seq = power_seq_lookup(seqs, "power-off"); > + if (!pb->power_off_seq) { > + dev_err(&pdev->dev, "missing power-off sequence\n"); > + return -EINVAL; > + } > + > + /* we must have exactly one PWM resource for this driver */ > + power_seq_for_each_resource(res, seqs) { > + if (res->type != POWER_SEQ_PWM) > + continue; > + if (pb->pwm) { > + dev_err(&pdev->dev, "more than one PWM used\n"); > + return -EINVAL; > + } > + /* keep the pwm at hand */ > + pb->pwm = res->pwm.pwm; > + } > + /* from here we should have a PWM */ > + if (!pb->pwm) { > + dev_err(&pdev->dev, "no PWM defined!\n"); > + return -EINVAL; > + } > + } else { > + /* use legacy interface */ > + pb->pwm = devm_pwm_get(&pdev->dev, NULL); > + if (IS_ERR(pb->pwm)) { > + dev_err(&pdev->dev, > + "unable to request PWM, trying legacy API\n"); > + > + pb->pwm = pwm_request(data->pwm_id, "pwm-backlight"); > + if (IS_ERR(pb->pwm)) { > + dev_err(&pdev->dev, > + "unable to request legacy PWM\n"); > + ret = PTR_ERR(pb->pwm); > + goto err_alloc; > + } > + } > + > + dev_dbg(&pdev->dev, "got pwm for backlight\n"); > + > + /* > + * The DT case will set the pwm_period_ns field to 0 and store > + * the period, parsed from the DT, in the PWM device. For the > + * non-DT case, set the period from platform data. > + */ > + if (data->pwm_period_ns > 0) > + pwm_set_period(pb->pwm, data->pwm_period_ns); > + } > + > if (data->levels) { > max = data->levels[data->max_brightness]; > pb->levels = data->levels; > @@ -213,28 +328,6 @@ static int pwm_backlight_probe(struct platform_device *pdev) > pb->exit = data->exit; > pb->dev = &pdev->dev; > > - pb->pwm = devm_pwm_get(&pdev->dev, NULL); > - if (IS_ERR(pb->pwm)) { > - dev_err(&pdev->dev, "unable to request PWM, trying legacy API\n"); > - > - pb->pwm = pwm_request(data->pwm_id, "pwm-backlight"); > - if (IS_ERR(pb->pwm)) { > - dev_err(&pdev->dev, "unable to request legacy PWM\n"); > - ret = PTR_ERR(pb->pwm); > - goto err_alloc; > - } > - } > - > - dev_dbg(&pdev->dev, "got pwm for backlight\n"); > - > - /* > - * The DT case will set the pwm_period_ns field to 0 and store the > - * period, parsed from the DT, in the PWM device. For the non-DT case, > - * set the period from platform data. > - */ > - if (data->pwm_period_ns > 0) > - pwm_set_period(pb->pwm, data->pwm_period_ns); > - > pb->period = pwm_get_period(pb->pwm); > pb->lth_brightness = data->lth_brightness * (pb->period / max); > > @@ -267,8 +360,7 @@ static int pwm_backlight_remove(struct platform_device *pdev) > struct pwm_bl_data *pb = dev_get_drvdata(&bl->dev); > > backlight_device_unregister(bl); > - pwm_config(pb->pwm, 0, pb->period); > - pwm_disable(pb->pwm); > + pwm_backlight_off(bl); > if (pb->exit) > pb->exit(&pdev->dev); > return 0; > @@ -282,8 +374,7 @@ static int pwm_backlight_suspend(struct device *dev) > > if (pb->notify) > pb->notify(pb->dev, 0); > - pwm_config(pb->pwm, 0, pb->period); > - pwm_disable(pb->pwm); > + pwm_backlight_off(bl); > if (pb->notify_after) > pb->notify_after(pb->dev, 0); > return 0; > diff --git a/include/linux/pwm_backlight.h b/include/linux/pwm_backlight.h > index 56f4a86..0dcec1d 100644 > --- a/include/linux/pwm_backlight.h > +++ b/include/linux/pwm_backlight.h > @@ -5,14 +5,28 @@ > #define __LINUX_PWM_BACKLIGHT_H > > #include <linux/backlight.h> > +#include <linux/power_seq.h> > > struct platform_pwm_backlight_data { > - int pwm_id; > unsigned int max_brightness; > unsigned int dft_brightness; > unsigned int lth_brightness; > - unsigned int pwm_period_ns; > unsigned int *levels; > + /* > + * New interface using power sequences. Must include exactly > + * two power sequences named 'power-on' and 'power-off'. If NULL, > + * the legacy interface is used. > + */ > + struct platform_power_seq_set *power_seqs; > + > + /* > + * Legacy interface - use power sequences instead! > + * > + * pwm_id and pwm_period_ns need only be specified > + * if get_pwm(dev, NULL) would return NULL. > + */ > + int pwm_id; > + unsigned int pwm_period_ns; > int (*init)(struct device *dev); > int (*notify)(struct device *dev, int brightness); > void (*notify_after)(struct device *dev, int brightness); Regards Tony P -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Friday 19 October 2012 17:20:36 Tony Prisk wrote: > On Fri, 2012-10-19 at 18:06 +0900, Alexandre Courbot wrote: > > +static void pwm_backlight_on(struct backlight_device *bl) > > +{ > > + struct pwm_bl_data *pb = dev_get_drvdata(&bl->dev); > > + int ret; > > + > > + if (pb->enabled) > > + return; > > + > > + if (pb->power_on_seq) { > > + ret = power_seq_run(pb->power_on_seq); > > + if (ret < 0) { > > + dev_err(&bl->dev, "cannot run power on > > sequence\n"); > > + return; > > + } > > + } else { > > + /* legacy framework */ > > + pwm_config(pb->pwm, 0, pb->period); > > + pwm_disable(pb->pwm); > > Is this right? pwm_disable() in the backlight_on function? Now everybody will notice that I never really tested the legacy interface. >_< Thanks, this was totally wrong indeed. Alex. -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 10/19/2012 03:20 AM, Tony Prisk wrote: > On Fri, 2012-10-19 at 18:06 +0900, Alexandre Courbot wrote: >> Make use of the power sequences specified in the device tree or platform >> data to control how the backlight is powered on and off. Tony, please do cut down the amount of the patch that you quote. If you don't, it's impossible to find your comments. Thanks. -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/Documentation/devicetree/bindings/video/backlight/pwm-backlight.txt b/Documentation/devicetree/bindings/video/backlight/pwm-backlight.txt index 1e4fc72..3ba25ea 100644 --- a/Documentation/devicetree/bindings/video/backlight/pwm-backlight.txt +++ b/Documentation/devicetree/bindings/video/backlight/pwm-backlight.txt @@ -14,15 +14,83 @@ Required properties: Optional properties: - pwm-names: a list of names for the PWM devices specified in the "pwms" property (see PWM binding[0]) + - low-threshold-brightness: brightness threshold low level. Sets the lowest + brightness value. + On some panels the backlight misbehaves if the duty cycle percentage of the + PWM wave is less than a certain level (say 20%). In this example the user + can set low-threshold-brightness to a value above 50 (ie, 20% of 255), thus + preventing the PWM duty cycle from going too low. + On setting low-threshold-brightness the range of brightness levels is + calculated in the range low-threshold-brightness to the maximum value in + brightness-levels, described above. + - pwm-names: name for the PWM device specified in the "pwms" property (see PWM + binding[0]). Necessary if power sequences are used + - power-sequences: Power sequences (see Power sequences[1]) used to bring the + backlight on and off. If this property is present, then two power + sequences named "power-on" and "power-off" must be defined to control how + the backlight is to be powered on and off. These sequences must reference + the PWM specified in the pwms property by its name, and can also reference + other resources supported by the power sequences mechanism [0]: Documentation/devicetree/bindings/pwm/pwm.txt +[1]: Documentation/devicetree/bindings/power/power_seq.txt Example: backlight { compatible = "pwm-backlight"; - pwms = <&pwm 0 5000000>; - brightness-levels = <0 4 8 16 32 64 128 255>; default-brightness-level = <6>; + low-threshold-brightness = <50>; + + /* resources used by the power sequences */ + pwms = <&pwm 0 5000000>; + pwm-names = "backlight"; + power-supply = <&backlight_reg>; + + power-sequences { + power-on { + step0 { + type = "regulator"; + id = "power"; + enable; + }; + step1 { + type = "delay"; + delay = <10000>; + }; + step2 { + type = "pwm"; + id = "backlight"; + enable; + }; + step3 { + type = "gpio"; + gpio = <&gpio 28 0>; + value = <1>; + }; + }; + + power-off { + step0 { + type = "gpio"; + gpio = <&gpio 28 0>; + value = <0>; + }; + step1 { + type = "pwm"; + id = "backlight"; + disable; + }; + step2 { + type = "delay"; + delay = <10000>; + }; + step3 { + type = "regulator"; + id = "power"; + disable; + }; + }; + }; }; diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig index c101697..c2e5f79 100644 --- a/drivers/video/backlight/Kconfig +++ b/drivers/video/backlight/Kconfig @@ -239,6 +239,7 @@ config BACKLIGHT_CARILLO_RANCH config BACKLIGHT_PWM tristate "Generic PWM based Backlight Driver" depends on PWM + select POWER_SEQ help If you have a LCD backlight adjustable by PWM, say Y to enable this driver. diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c index 069983c..e607c6e 100644 --- a/drivers/video/backlight/pwm_bl.c +++ b/drivers/video/backlight/pwm_bl.c @@ -27,6 +27,12 @@ struct pwm_bl_data { unsigned int period; unsigned int lth_brightness; unsigned int *levels; + bool enabled; + struct power_seq_set power_seqs; + struct power_seq *power_on_seq; + struct power_seq *power_off_seq; + + /* Legacy callbacks */ int (*notify)(struct device *, int brightness); void (*notify_after)(struct device *, @@ -35,6 +41,52 @@ struct pwm_bl_data { void (*exit)(struct device *); }; +static void pwm_backlight_on(struct backlight_device *bl) +{ + struct pwm_bl_data *pb = dev_get_drvdata(&bl->dev); + int ret; + + if (pb->enabled) + return; + + if (pb->power_on_seq) { + ret = power_seq_run(pb->power_on_seq); + if (ret < 0) { + dev_err(&bl->dev, "cannot run power on sequence\n"); + return; + } + } else { + /* legacy framework */ + pwm_config(pb->pwm, 0, pb->period); + pwm_disable(pb->pwm); + } + + pb->enabled = true; +} + +static void pwm_backlight_off(struct backlight_device *bl) +{ + struct pwm_bl_data *pb = dev_get_drvdata(&bl->dev); + int ret; + + if (!pb->enabled) + return; + + if (pb->power_off_seq) { + ret = power_seq_run(pb->power_off_seq); + if (ret < 0) { + dev_err(&bl->dev, "cannot run power off sequence\n"); + return; + } + } else { + /* legacy framework */ + pwm_enable(pb->pwm); + return; + } + + pb->enabled = false; +} + static int pwm_backlight_update_status(struct backlight_device *bl) { struct pwm_bl_data *pb = dev_get_drvdata(&bl->dev); @@ -51,8 +103,7 @@ static int pwm_backlight_update_status(struct backlight_device *bl) brightness = pb->notify(pb->dev, brightness); if (brightness == 0) { - pwm_config(pb->pwm, 0, pb->period); - pwm_disable(pb->pwm); + pwm_backlight_off(bl); } else { int duty_cycle; @@ -66,7 +117,7 @@ static int pwm_backlight_update_status(struct backlight_device *bl) duty_cycle = pb->lth_brightness + (duty_cycle * (pb->period - pb->lth_brightness) / max); pwm_config(pb->pwm, duty_cycle, pb->period); - pwm_enable(pb->pwm); + pwm_backlight_on(bl); } if (pb->notify_after) @@ -145,11 +196,10 @@ static int pwm_backlight_parse_dt(struct device *dev, data->max_brightness--; } - /* - * TODO: Most users of this driver use a number of GPIOs to control - * backlight power. Support for specifying these needs to be - * added. - */ + /* read power sequences */ + data->power_seqs = devm_of_parse_power_seq_set(dev); + if (IS_ERR(data->power_seqs)) + return PTR_ERR(data->power_seqs); return 0; } @@ -172,6 +222,7 @@ static int pwm_backlight_probe(struct platform_device *pdev) { struct platform_pwm_backlight_data *data = pdev->dev.platform_data; struct platform_pwm_backlight_data defdata; + struct power_seq_resource *res; struct backlight_properties props; struct backlight_device *bl; struct pwm_bl_data *pb; @@ -180,7 +231,9 @@ static int pwm_backlight_probe(struct platform_device *pdev) if (!data) { ret = pwm_backlight_parse_dt(&pdev->dev, &defdata); - if (ret < 0) { + if (ret == -EPROBE_DEFER) { + return ret; + } else if (ret < 0) { dev_err(&pdev->dev, "failed to find platform data\n"); return ret; } @@ -201,6 +254,68 @@ static int pwm_backlight_probe(struct platform_device *pdev) goto err_alloc; } + if (data->power_seqs) { + /* use power sequences */ + struct power_seq_set *seqs = &pb->power_seqs; + + power_seq_set_init(seqs, &pdev->dev); + power_seq_set_add_sequences(seqs, data->power_seqs); + + /* Check that the required sequences are here */ + pb->power_on_seq = power_seq_lookup(seqs, "power-on"); + if (!pb->power_on_seq) { + dev_err(&pdev->dev, "missing power-on sequence\n"); + return -EINVAL; + } + pb->power_off_seq = power_seq_lookup(seqs, "power-off"); + if (!pb->power_off_seq) { + dev_err(&pdev->dev, "missing power-off sequence\n"); + return -EINVAL; + } + + /* we must have exactly one PWM resource for this driver */ + power_seq_for_each_resource(res, seqs) { + if (res->type != POWER_SEQ_PWM) + continue; + if (pb->pwm) { + dev_err(&pdev->dev, "more than one PWM used\n"); + return -EINVAL; + } + /* keep the pwm at hand */ + pb->pwm = res->pwm.pwm; + } + /* from here we should have a PWM */ + if (!pb->pwm) { + dev_err(&pdev->dev, "no PWM defined!\n"); + return -EINVAL; + } + } else { + /* use legacy interface */ + pb->pwm = devm_pwm_get(&pdev->dev, NULL); + if (IS_ERR(pb->pwm)) { + dev_err(&pdev->dev, + "unable to request PWM, trying legacy API\n"); + + pb->pwm = pwm_request(data->pwm_id, "pwm-backlight"); + if (IS_ERR(pb->pwm)) { + dev_err(&pdev->dev, + "unable to request legacy PWM\n"); + ret = PTR_ERR(pb->pwm); + goto err_alloc; + } + } + + dev_dbg(&pdev->dev, "got pwm for backlight\n"); + + /* + * The DT case will set the pwm_period_ns field to 0 and store + * the period, parsed from the DT, in the PWM device. For the + * non-DT case, set the period from platform data. + */ + if (data->pwm_period_ns > 0) + pwm_set_period(pb->pwm, data->pwm_period_ns); + } + if (data->levels) { max = data->levels[data->max_brightness]; pb->levels = data->levels; @@ -213,28 +328,6 @@ static int pwm_backlight_probe(struct platform_device *pdev) pb->exit = data->exit; pb->dev = &pdev->dev; - pb->pwm = devm_pwm_get(&pdev->dev, NULL); - if (IS_ERR(pb->pwm)) { - dev_err(&pdev->dev, "unable to request PWM, trying legacy API\n"); - - pb->pwm = pwm_request(data->pwm_id, "pwm-backlight"); - if (IS_ERR(pb->pwm)) { - dev_err(&pdev->dev, "unable to request legacy PWM\n"); - ret = PTR_ERR(pb->pwm); - goto err_alloc; - } - } - - dev_dbg(&pdev->dev, "got pwm for backlight\n"); - - /* - * The DT case will set the pwm_period_ns field to 0 and store the - * period, parsed from the DT, in the PWM device. For the non-DT case, - * set the period from platform data. - */ - if (data->pwm_period_ns > 0) - pwm_set_period(pb->pwm, data->pwm_period_ns); - pb->period = pwm_get_period(pb->pwm); pb->lth_brightness = data->lth_brightness * (pb->period / max); @@ -267,8 +360,7 @@ static int pwm_backlight_remove(struct platform_device *pdev) struct pwm_bl_data *pb = dev_get_drvdata(&bl->dev); backlight_device_unregister(bl); - pwm_config(pb->pwm, 0, pb->period); - pwm_disable(pb->pwm); + pwm_backlight_off(bl); if (pb->exit) pb->exit(&pdev->dev); return 0; @@ -282,8 +374,7 @@ static int pwm_backlight_suspend(struct device *dev) if (pb->notify) pb->notify(pb->dev, 0); - pwm_config(pb->pwm, 0, pb->period); - pwm_disable(pb->pwm); + pwm_backlight_off(bl); if (pb->notify_after) pb->notify_after(pb->dev, 0); return 0; diff --git a/include/linux/pwm_backlight.h b/include/linux/pwm_backlight.h index 56f4a86..0dcec1d 100644 --- a/include/linux/pwm_backlight.h +++ b/include/linux/pwm_backlight.h @@ -5,14 +5,28 @@ #define __LINUX_PWM_BACKLIGHT_H #include <linux/backlight.h> +#include <linux/power_seq.h> struct platform_pwm_backlight_data { - int pwm_id; unsigned int max_brightness; unsigned int dft_brightness; unsigned int lth_brightness; - unsigned int pwm_period_ns; unsigned int *levels; + /* + * New interface using power sequences. Must include exactly + * two power sequences named 'power-on' and 'power-off'. If NULL, + * the legacy interface is used. + */ + struct platform_power_seq_set *power_seqs; + + /* + * Legacy interface - use power sequences instead! + * + * pwm_id and pwm_period_ns need only be specified + * if get_pwm(dev, NULL) would return NULL. + */ + int pwm_id; + unsigned int pwm_period_ns; int (*init)(struct device *dev); int (*notify)(struct device *dev, int brightness); void (*notify_after)(struct device *dev, int brightness);
Make use of the power sequences specified in the device tree or platform data to control how the backlight is powered on and off. Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> --- .../bindings/video/backlight/pwm-backlight.txt | 72 ++++++++- drivers/video/backlight/Kconfig | 1 + drivers/video/backlight/pwm_bl.c | 161 ++++++++++++++++----- include/linux/pwm_backlight.h | 18 ++- 4 files changed, 213 insertions(+), 39 deletions(-)