Hi Alexander,
On Fri, Nov 30, 2012 at 02:18:00PM +0400, Alexander Shiyan wrote:
> > On Thu, Nov 29, 2012 at 09:28:59PM +0400, Alexander Shiyan wrote:
> > > This patch adds a new driver for the beeper controlled via GPIO pin.
> > > The driver does not depend on the architecture and is positioned as
> > > a replacement for the specific drivers that are used for this function,
> > > for example drivers/input/misc/ixp4xx-beeper.
> > > Since this patch is RFC only, inline comments are welcome.
> ...
> > > +static int gpio_beeper_event(struct input_dev *dev, unsigned int type,
> > > + unsigned int code, int value)
> > > +{
> > > + struct gpio_beeper_priv *s = input_get_drvdata(dev);
> > > +
> > > + if ((type != EV_SND) || (code != SND_BELL))
> > > + return -ENOTSUPP;
> > > +
> > > + if (value < 0)
> > > + return -EINVAL;
> > > +
> > > + if (!value)
> > > + value = 1000;
> > > +
> > > + /* Turning beeper ON */
> > > + gpio_beeper_change(s, 1);
> >
> > You are running under spinlock, you can't touch GPIO here using
> > "cansleep" operations.
> >
> > > + /* Schedule work for turning OFF */
> > > + mod_delayed_work(system_wq, &s->work, msecs_to_jiffies(value));
> > > +
> >
> > This is incorrect. The "value" here is pitch, not the duration of sound.
> > The callers are responsible to shut off the sound. The difference
> > between SND_BELL and SND_TONE is that latter allows controlling pitch
> > while the former uses driver- and platform-specific pitch.
> As it turned out, I understand the purpose of the parameter is incorrect.
> My mistake.
>
> > I think the driver should look like in the patch below. Can you please
> > tell me if it works for you?
> Works. The test was on ARM CLPS711X board with the driver is compiled
> into the kernel, ie without modules. Non-critical comments inlined.
>
Excellent, thank you.
>
> > Input: Add new driver for GPIO beeper
> >
> > From: Alexander Shiyan <[email protected]>
> >
> > This patch adds a new driver for the beeper controlled via GPIO pin.
> > The driver does not depend on the architecture and is positioned as
> > a replacement for the specific drivers that are used for this function,
> > for example drivers/input/misc/ixp4xx-beeper.
> > Since this patch is RFC only, inline comments are welcome.
> >
> > Signed-off-by: Dmitry Torokhov <[email protected]>
> > ---
> > drivers/input/misc/Kconfig | 9 +
> > drivers/input/misc/Makefile | 1
> > drivers/input/misc/gpio-beeper.c | 154
> > +++++++++++++++++++++++
> > include/linux/platform_data/input-gpio-beeper.h | 20 +++
>
> > +static int gpio_beeper_probe(struct platform_device *pdev)
> > +{
> > + struct device *dev = &pdev->dev;
> > + const struct gpio_beeper_pdata *pdata = dev_get_platdata(dev);
> > + struct gpio_beeper *beeper;
> > + struct input_dev *input;
> > + int error;
> > +
> > + if (!pdata) {
> > + dev_err(dev, "Missing platform data\n");
> > + return -EINVAL;
> > + }
> > +
> > + if (!gpio_is_valid(pdata->gpio_nr)) {
> > + dev_err(dev, "Invalid gpio %i\n", pdata->gpio_nr);
> > + return -EINVAL;
> > + }
> > +
> > + beeper = devm_kzalloc(&pdev->dev, sizeof(struct gpio_beeper),
> > + GFP_KERNEL);
> I would prefer to do when moving padding on brackets.
I am not sure what you were trying to say here... Are you saying
GFP_KERNEL should be aligned with opening parenthesis?
>
> > + if (!beeper) {
> > + dev_err(dev, "Memory allocate error\n");
> > + return -ENOMEM;
> > + }
> > +
> > + beeper->gpio_nr = pdata->gpio_nr;
> > + beeper->active_low = pdata->active_low;
> > +
> > + INIT_WORK(&beeper->work, gpio_beeper_work);
> > + snprintf(beeper->phys, sizeof(beeper->phys),
> > + "%s/input0", dev_name(dev));
> > +
> > + input = devm_input_allocate_device(dev);
> I am temporaty replace this function to input_allocate_device() because
> I am tested this driver on 2.6.8.
Surely not 2.6? Anyway for devm_input_allocate_device() support you need
the following commit from my 'next' branch in
git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input.git
commit 2be975c6d920de989ff5e4bc09ffe87e59d94662
Author: Dmitry Torokhov <[email protected]>
Date: Sat Nov 3 12:16:12 2012 -0700
Input: introduce managed input devices (add devres support)
>
> > + if (!input) {
> > + dev_err(&pdev->dev, "Input device allocate error\n");
> > + return -ENOMEM;
> > + }
> > +
> > + input->name = pdata->name ?: "GPIO Beeper";
> > + input->phys = beeper->phys;
> > + input->id.bustype = BUS_HOST;
> > + input->id.vendor = 0x0001;
> > + input->id.product = 0x0001;
> > + input->id.version = 0x0100;
> > +
> IMHO, no empty line needed here.
>
> > + input->close = gpio_beeper_close;
> > + input->event = gpio_beeper_event;
> ...
> > +
> > + input_set_capability(input, EV_SND, SND_BELL);
> > +
> > + error = devm_gpio_request(dev, beeper->gpio_nr, input->name);
> > + if (error) {
> > + dev_err(dev, "Unable to claim gpio %i\n", beeper->gpio_nr);
> > + return error;
> > + }
> > +
> > + gpio_direction_output(beeper->gpio_nr, beeper->active_low);
> > +
> > + beeper->input = input;
> > + input_set_drvdata(input, beeper);
> > + platform_set_drvdata(pdev, beeper);
> > +
> > + return input_register_device(beeper->input);
> > +}
> > +
> > +static void gpio_beeper_shutdown(struct platform_device *pdev)
> > +{
> > + struct gpio_beeper *beeper = platform_get_drvdata(pdev);
> > +
> > + /* Turning OFF immediately */
> > + gpio_beeper_close(beeper->input);
> > +}
> > +
> > +static struct platform_driver gpio_beeper_platform_driver = {
> > + .driver = {
> > + .name = "gpio-beeper",
> > + .owner = THIS_MODULE,
> > + },
> > + .probe = gpio_beeper_probe,
> > + .shutdown = gpio_beeper_shutdown,
> > +};
> > +module_platform_driver(gpio_beeper_platform_driver);
> No "remove" function?
With all resources being devm_* managed (and shuttign off beeper
happening in gpio_keys_close()) the remove function would be just an
empty stub. As far as I can see platform devices not have to have a
remove function, but testing this by unloading the driver or unbinding
it via sysfs would be nice.
Thanks.
--
Dmitry
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