Hi Frieder, On Thu, Jan 19, 2017 at 04:24:08PM +0100, Frieder Schrempf wrote: > 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 volume adjustment is done by changing the duty cycle of > the pwm signal. > > This patch adds the sysfs interface with 5 default volume > levels (0 - mute, 4 - max. volume). > > Signed-off-by: Frieder Schrempf <[email protected]> > --- > Changes in v3: > - update date > > .../ABI/testing/sysfs-class-input-pwm-beeper | 17 ++++++ > drivers/input/misc/pwm-beeper.c | 71 > +++++++++++++++++++++- > 2 files changed, 87 insertions(+), 1 deletion(-) > create mode 100644 Documentation/ABI/testing/sysfs-class-input-pwm-beeper > > diff --git a/Documentation/ABI/testing/sysfs-class-input-pwm-beeper > b/Documentation/ABI/testing/sysfs-class-input-pwm-beeper > new file mode 100644 > index 0000000..c878a1d > --- /dev/null > +++ b/Documentation/ABI/testing/sysfs-class-input-pwm-beeper > @@ -0,0 +1,17 @@ > +What: /sys/class/input/input(x)/volume
Only generic (i.e. applicable to all input devices) attributes can be present in /sys/class/input/input(x)/, and volume certainly isn't such attribute. Please move them to the pwm-beeper platform device itself. > +Date: January 2017 > +KernelVersion: > +Contact: Frieder Schrempf <[email protected]> > +Description: > + Control the volume of this pwm-beeper. Values > + are between 0 and max_volume_level. This file will also > + show the current volume level stored in the driver. > + > +What: /sys/class/input/input(x)/max_volume_level > +Date: January 2017 > +KernelVersion: > +Contact: Frieder Schrempf <[email protected]> > +Description: > + This file shows the maximum volume level that can be > + assigned to volume. > + > diff --git a/drivers/input/misc/pwm-beeper.c b/drivers/input/misc/pwm-beeper.c > index 5f9655d..3ed21da 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 <[email protected]> > + * > + * Copyright (C) 2016, Frieder Schrempf <[email protected]> > + * (volume support) > + * > * PWM beeper driver > * > * This program is free software; you can redistribute it and/or modify it > @@ -27,16 +31,77 @@ struct pwm_beeper { > struct pwm_device *pwm; > struct work_struct work; > unsigned long period; > + unsigned int volume; > + unsigned int volume_levels[] = {0, 8, 20, 40, 500}; Does this actually work? Anyway, you are not allowing to set differentr values in for different beepers, so take the array out of the structure. > + 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; Why? There are no failures below. > + if (volume > beeper->max_volume_level) > + volume = beeper->max_volume_level; Return -EINVAL maybe? > + pr_debug("set volume to %u\n", volume); > + if (beeper->volume != volume) > + beeper->volume = volume; Why? > + 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); Drop "level", it is cleaner. > + > +static struct attribute *bp_device_attributes[] = { pwm_beeper_atttributes > + &dev_attr_volume.attr, > + &dev_attr_max_volume_level.attr, > + NULL, > +}; > + > +static struct attribute_group bp_device_attr_group = { pwm_beeper_attribute_group > + .attrs = bp_device_attributes, > +}; > + > +static const struct attribute_group *bp_device_attr_groups[] = { > + &bp_device_attr_group, > + NULL, > +}; > + > static void __pwm_beeper_set(struct pwm_beeper *beeper) > { > unsigned long period = beeper->period; > > if (period) { > - pwm_config(beeper->pwm, period / 2, period); > + pwm_config(beeper->pwm, > + period / 1000 * beeper->volume_levels[beeper->volume], > + period); > pwm_enable(beeper->pwm); > } else > pwm_disable(beeper->pwm); > @@ -123,6 +188,8 @@ static int pwm_beeper_probe(struct platform_device *pdev) > > INIT_WORK(&beeper->work, pwm_beeper_work); > > + beeper->max_volume_level = ARRAY_SIZE(beeper->volume_levels) - 1; > + > beeper->input = input_allocate_device(); > if (!beeper->input) { > dev_err(&pdev->dev, "Failed to allocate input device\n"); > @@ -146,6 +213,8 @@ 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); > -- > 2.7.4 > Thanks. -- Dmitry
