| Message ID | 1460044644-12419-1-git-send-email-frieder.schrempf@exceet.de |
|---|---|
| State | Changes Requested, archived |
| Headers | show |
On Thu, Apr 07, 2016 at 03:58:40PM +0000, Schrempf Frieder wrote: > Make the driver accept different volume levels via sysfs. > This can be helpful if the beep/bell sound intensity needs > to be adapted to the environment of the device. It is preferred that bindings be a separate patch. Also, this is 2 independent features: the sysfs interface and DT properties. So that is probably 3 patches. Also, sysfs interfaces are supposed to be documented. > > The number of volume levels available and their values can > be specified via device tree (similar to pwm-backlight). > > This patch was tested with linux-imx 3.10.17 and was > applied to current mainline without any changes. You need to test with something not 3 years old... > > Signed-off-by: Frieder Schrempf <frieder.schrempf@exceet.de> > --- > .../devicetree/bindings/input/pwm-beeper.txt | 20 ++++ > drivers/input/misc/pwm-beeper.c | 109 ++++++++++++++++++- > 2 files changed, 126 insertions(+), 3 deletions(-) > > diff --git a/Documentation/devicetree/bindings/input/pwm-beeper.txt b/Documentation/devicetree/bindings/input/pwm-beeper.txt > index be332ae..153cd3f 100644 > --- a/Documentation/devicetree/bindings/input/pwm-beeper.txt > +++ b/Documentation/devicetree/bindings/input/pwm-beeper.txt > @@ -5,3 +5,23 @@ Registers a PWM device as beeper. > Required properties: > - compatible: should be "pwm-beeper" > - pwms: phandle to the physical PWM device > +- volume-levels: Array of distinct volume levels. These need to be in the > + range of 0 to 500, while 0 means 0% duty cycle (mute) and 500 means > + 50% duty cycle (max volume). Where does the scale of 0-500 come from? It is tenth of a percent? How many array entries? > + Please note that the actual volume of most beepers is highly > + non-linear, which means that low volume levels are probably somewhere > + in the range of 1 to 30 (0.1-3% duty cycle). > +- default-volume-level: the default volume level (index into the > + array defined by the "volume-levels" property) > + > +The volume level can be set via sysfs under /sys/class/input/inputX/volume. > +The maximum volume level index can be read from /sys/class/input/inputX/max_volume_level. > + > +Example: > + > + pwm-beeper { > + compatible = "pwm-beeper"; > + pwms = <&pwm4 0 5000>; > + volume-levels = <0 8 20 40 500>; > + default-volume-level = <4>; > + }; -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Thank you Rob for looking at my first kernel contribution. I come back to it now, as I had some time to process your comments. On 11.04.2016 17:21, Rob Herring wrote: > On Thu, Apr 07, 2016 at 03:58:40PM +0000, Schrempf Frieder wrote: >> Make the driver accept different volume levels via sysfs. >> This can be helpful if the beep/bell sound intensity needs >> to be adapted to the environment of the device. > > It is preferred that bindings be a separate patch. Also, this is 2 > independent features: the sysfs interface and DT properties. So that is > probably 3 patches. > > Also, sysfs interfaces are supposed to be documented. I have splitted this into 3 patches and will send them soon as v2. I also added documentation for the sysfs interface. > >> >> The number of volume levels available and their values can >> be specified via device tree (similar to pwm-backlight). >> >> This patch was tested with linux-imx 3.10.17 and was >> applied to current mainline without any changes. > > You need to test with something not 3 years old... I tested the v2 patches with Linux 4.7.4 now. > >> >> Signed-off-by: Frieder Schrempf <frieder.schrempf@exceet.de> >> --- >> .../devicetree/bindings/input/pwm-beeper.txt | 20 ++++ >> drivers/input/misc/pwm-beeper.c | 109 ++++++++++++++++++- >> 2 files changed, 126 insertions(+), 3 deletions(-) >> >> diff --git a/Documentation/devicetree/bindings/input/pwm-beeper.txt b/Documentation/devicetree/bindings/input/pwm-beeper.txt >> index be332ae..153cd3f 100644 >> --- a/Documentation/devicetree/bindings/input/pwm-beeper.txt >> +++ b/Documentation/devicetree/bindings/input/pwm-beeper.txt >> @@ -5,3 +5,23 @@ Registers a PWM device as beeper. >> Required properties: >> - compatible: should be "pwm-beeper" >> - pwms: phandle to the physical PWM device >> +- volume-levels: Array of distinct volume levels. These need to be in the >> + range of 0 to 500, while 0 means 0% duty cycle (mute) and 500 means >> + 50% duty cycle (max volume). > > Where does the scale of 0-500 come from? It is tenth of a percent? I used tenth of a percent because this is needed to define low volume levels with pwm duty cycles in the range of <1%. This is necessary because of the highly non-linear relation between duty cycle and actual perceived volume. The upper limit of 500 therefore results from 50% being the duty cycle with maximum volume. > > How many array entries? The array size and therefore the number of volume levels is dynamic and only defined by the number of entries in the volume-levels property. > >> + Please note that the actual volume of most beepers is highly >> + non-linear, which means that low volume levels are probably somewhere >> + in the range of 1 to 30 (0.1-3% duty cycle). >> +- default-volume-level: the default volume level (index into the >> + array defined by the "volume-levels" property) >> + >> +The volume level can be set via sysfs under /sys/class/input/inputX/volume. >> +The maximum volume level index can be read from /sys/class/input/inputX/max_volume_level. >> + >> +Example: >> + >> + pwm-beeper { >> + compatible = "pwm-beeper"; >> + pwms = <&pwm4 0 5000>; >> + volume-levels = <0 8 20 40 500>; >> + default-volume-level = <4>; >> + };-- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Make the driver accept switching volume levels via sysfs. This can be helpful if the beep/bell sound intensity needs to be adapted to the environment of the device. The number of volume levels available and their values can be specified via device tree (similar to pwm-backlight). The volume adjustment is done by changing the duty cycle of the pwm signal. Changes in v2: - split into 3 separate patches - make volume devicetree properties optional - tested with Linux 4.7.4 Frieder Schrempf (3): input: pwm-beeper: add feature to set volume via sysfs input: pwm-beeper: add documentation for volume devicetree bindings input: pwm-beeper: add devicetree bindings to set volume levels .../ABI/testing/sysfs-class-input-pwm-beeper | 17 +++ .../devicetree/bindings/input/pwm-beeper.txt | 22 ++++ drivers/input/misc/pwm-beeper.c | 118 ++++++++++++++++++++- 3 files changed, 155 insertions(+), 2 deletions(-) create mode 100644 Documentation/ABI/testing/sysfs-class-input-pwm-beeper
diff --git a/Documentation/devicetree/bindings/input/pwm-beeper.txt b/Documentation/devicetree/bindings/input/pwm-beeper.txt index be332ae..153cd3f 100644 --- a/Documentation/devicetree/bindings/input/pwm-beeper.txt +++ b/Documentation/devicetree/bindings/input/pwm-beeper.txt @@ -5,3 +5,23 @@ Registers a PWM device as beeper. Required properties: - compatible: should be "pwm-beeper" - pwms: phandle to the physical PWM device +- volume-levels: Array of distinct volume levels. These need to be in the + range of 0 to 500, while 0 means 0% duty cycle (mute) and 500 means + 50% duty cycle (max volume). + Please note that the actual volume of most beepers is highly + non-linear, which means that low volume levels are probably somewhere + in the range of 1 to 30 (0.1-3% duty cycle). +- default-volume-level: the default volume level (index into the + array defined by the "volume-levels" property) + +The volume level can be set via sysfs under /sys/class/input/inputX/volume. +The maximum volume level index can be read from /sys/class/input/inputX/max_volume_level. + +Example: + + pwm-beeper { + compatible = "pwm-beeper"; + pwms = <&pwm4 0 5000>; + volume-levels = <0 8 20 40 500>; + default-volume-level = <4>; + }; diff --git a/drivers/input/misc/pwm-beeper.c b/drivers/input/misc/pwm-beeper.c index f2261ab..f3eb8f8 100644 --- a/drivers/input/misc/pwm-beeper.c +++ b/drivers/input/misc/pwm-beeper.c @@ -1,5 +1,9 @@ /* * Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de> + * + * Copyright (C) 2016, Frieder Schrempf <frieder.schrempf@exceet.de> + * (volume support) + * * PWM beeper driver * * This program is free software; you can redistribute it and/or modify it @@ -25,10 +29,69 @@ struct pwm_beeper { struct input_dev *input; struct pwm_device *pwm; unsigned long period; + unsigned int volume; + unsigned int *volume_levels; + unsigned int max_volume_level; }; #define HZ_TO_NANOSECONDS(x) (1000000000UL/(x)) +static ssize_t beeper_show_volume(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct pwm_beeper *beeper = dev_get_drvdata(dev); + + return sprintf(buf, "%d\n", beeper->volume); +} + +static ssize_t beeper_show_max_volume_level(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct pwm_beeper *beeper = dev_get_drvdata(dev); + + return sprintf(buf, "%d\n", beeper->max_volume_level); +} + +static ssize_t beeper_store_volume(struct device *dev, + struct device_attribute *attr, const char *buf, size_t count) +{ + int rc; + struct pwm_beeper *beeper = dev_get_drvdata(dev); + unsigned int volume; + + rc = kstrtouint(buf, 0, &volume); + if (rc) + return rc; + + rc = -ENXIO; + if (volume > beeper->max_volume_level) + volume = beeper->max_volume_level; + pr_debug("set volume to %u\n", volume); + if (beeper->volume != volume) + beeper->volume = volume; + rc = count; + + return rc; +} + +static DEVICE_ATTR(volume, 0644, beeper_show_volume, beeper_store_volume); +static DEVICE_ATTR(max_volume_level, 0644, beeper_show_max_volume_level, NULL); + +static struct attribute *bp_device_attributes[] = { + &dev_attr_volume.attr, + &dev_attr_max_volume_level.attr, + NULL, +}; + +static struct attribute_group bp_device_attr_group = { + .attrs = bp_device_attributes, +}; + +static const struct attribute_group *bp_device_attr_groups[] = { + &bp_device_attr_group, + NULL, +}; + static int pwm_beeper_event(struct input_dev *input, unsigned int type, unsigned int code, int value) { @@ -53,7 +116,9 @@ static int pwm_beeper_event(struct input_dev *input, pwm_disable(beeper->pwm); } else { period = HZ_TO_NANOSECONDS(value); - ret = pwm_config(beeper->pwm, period / 2, period); + ret = pwm_config(beeper->pwm, + period / 1000 * beeper->volume_levels[beeper->volume], + period); if (ret) return ret; ret = pwm_enable(beeper->pwm); @@ -68,8 +133,11 @@ static int pwm_beeper_event(struct input_dev *input, static int pwm_beeper_probe(struct platform_device *pdev) { unsigned long pwm_id = (unsigned long)dev_get_platdata(&pdev->dev); + struct device_node *np = pdev->dev.of_node; struct pwm_beeper *beeper; - int error; + struct property *prop; + int error, length; + u32 value; beeper = kzalloc(sizeof(*beeper), GFP_KERNEL); if (!beeper) @@ -87,6 +155,36 @@ static int pwm_beeper_probe(struct platform_device *pdev) goto err_free; } + /* determine the number of volume levels */ + prop = of_find_property(np, "volume-levels", &length); + if (!prop) + return -EINVAL; + + beeper->max_volume_level = length / sizeof(u32); + + /* read volume levels from DT property */ + if (beeper->max_volume_level > 0) { + size_t size = sizeof(*beeper->volume_levels) * + beeper->max_volume_level; + + beeper->volume_levels = devm_kzalloc(&(pdev->dev), size, + GFP_KERNEL); + if (!beeper->volume_levels) + return -ENOMEM; + + error = of_property_read_u32_array(np, "volume-levels", + beeper->volume_levels, + beeper->max_volume_level); + + error = of_property_read_u32(np, "default-volume-level", + &value); + if (error < 0) + return error; + + beeper->volume = value; + beeper->max_volume_level--; + } + beeper->input = input_allocate_device(); if (!beeper->input) { dev_err(&pdev->dev, "Failed to allocate input device\n"); @@ -109,6 +207,8 @@ static int pwm_beeper_probe(struct platform_device *pdev) input_set_drvdata(beeper->input, beeper); + beeper->input->dev.groups = bp_device_attr_groups; + error = input_register_device(beeper->input); if (error) { dev_err(&pdev->dev, "Failed to register input device: %d\n", error); @@ -158,7 +258,10 @@ static int __maybe_unused pwm_beeper_resume(struct device *dev) struct pwm_beeper *beeper = dev_get_drvdata(dev); if (beeper->period) { - pwm_config(beeper->pwm, beeper->period / 2, beeper->period); + pwm_config(beeper->pwm, + beeper->period / 1000 * + beeper->volume_levels[beeper->volume], + beeper->period); pwm_enable(beeper->pwm); }
Make the driver accept different volume levels via sysfs. This can be helpful if the beep/bell sound intensity needs to be adapted to the environment of the device. The number of volume levels available and their values can be specified via device tree (similar to pwm-backlight). This patch was tested with linux-imx 3.10.17 and was applied to current mainline without any changes. Signed-off-by: Frieder Schrempf <frieder.schrempf@exceet.de> --- .../devicetree/bindings/input/pwm-beeper.txt | 20 ++++ drivers/input/misc/pwm-beeper.c | 109 ++++++++++++++++++- 2 files changed, 126 insertions(+), 3 deletions(-)