Re: [RFC][PATCH] Add support for hook switch on ams-delta

Janusz Krzysztofik
2009-06-03T09:03:47Z

Hi Jonathan,

Wednesday 03 June 2009 00:04:33 Jonathan McDowell napisał(a):
> I'm obviously too late as I've seen the "Applied" mail,

No problem, I'm glad to hear from you.

> but some
> comments:
>
> * I don't think SW_HEADPHONE_INSERT is appropriate. input guys, is it
> not reasonable to have SW_PHONE_HOOK or similar?

I do share you point of view. However, I didn't want to start a discussion if
there is a need for another symbol or not before the patch got any
acceptance.

> * We assume the bootloader does the appropriate GPIO pin setup for us,
> so I don't think your omap_cfg_reg is required but it doesn't hurt in
> the unlikely event we ever replace the Amstrad PBL.

OK, let it stay there. Do you see a need for replaceing it with a new
ams_delta_hook_switch_init() function call that just calls omap_cfg_reg()?

> * The commented out code to include the GPIO status in sysfs shouldn't
> be included.

Yes, I put it there to get a feedback.

> Does the input layer not provide a way to obtain the
> state of the switch?

Yes, it does, with EVIOCGSW ioctl()[1]. I personally don't like this way of
getting the switch status and would rather see it available over sysfs.
However, input guys may have their own preferences and gpio-keys driver
belongs to them.

Thanks,
Janusz

[1] http://www.spinics.net/lists/linux-input/msg03482.html

P.S. I include my Signed-off-by, as Tony have requested, to avoid the code
without one floating around.

Signed-off-by: Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>

> > diff -Npru a/arch/arm/mach-omap1/board-ams-delta.c
> > b/arch/arm/mach-omap1/board-ams-delta.c ---
> > a/arch/arm/mach-omap1/board-ams-delta.c 2009-05-17 17:58:18.000000000
> > +0200 +++ b/arch/arm/mach-omap1/board-ams-delta.c 2009-05-17
> > 16:22:59.000000000 +0200 @@ -15,6 +15,7 @@
> > #include <linux/kernel.h>
> > #include <linux/init.h>
> > #include <linux/input.h>
> > +#include <linux/gpio_keys.h>
> > #include <linux/platform_device.h>
> >
> > #include <mach/hardware.h>
> > @@ -213,10 +214,35 @@ static struct platform_device ams_delta_
> > .id = -1
> > };
> >
> > +static struct gpio_keys_button ams_delta_gpio_keys_buttons[] = {
> > + [0] = {
> > + .desc = "hook_switch",
> > + .type = EV_SW, /* or EV_KEY ? */
> > + .code = SW_HEADPHONE_INSERT, /* or a new one ? */
> > + .active_low = 1,
> > + .gpio = AMS_DELTA_GPIO_PIN_HOOK_SWITCH,
> > + .debounce_interval = 10,
> > + },
> > +};
> > +
> > +static struct gpio_keys_platform_data ams_delta_gpio_keys = {
> > + .buttons = ams_delta_gpio_keys_buttons,
> > + .nbuttons = ARRAY_SIZE(ams_delta_gpio_keys_buttons),
> > +};
> > +
> > +static struct platform_device ams_delta_gpio_keys_device = {
> > + .name = "gpio-keys",
> > + .id = -1,
> > + .dev = {
> > + .platform_data = &ams_delta_gpio_keys,
> > + },
> > +};
> > +
> > static struct platform_device *ams_delta_devices[] __initdata = {
> > &ams_delta_kp_device,
> > &ams_delta_lcd_device,
> > &ams_delta_led_device,
> > + &ams_delta_gpio_keys_device,
> > };
> >
> > static void __init ams_delta_init(void)
> > @@ -233,6 +259,13 @@ static void __init ams_delta_init_irq(vo
> >
> > omap_usb_init(&ams_delta_usb_config);
> > platform_add_devices(ams_delta_devices, ARRAY_SIZE(ams_delta_devices));
> > +
> > + omap_cfg_reg(P20_1610_GPIO4); /* is this required? */
> > +
> > + /* The hook switch state could be exposed over sysfs with
> > gpio_export(). + * This should be done after the gpio-keys driver calls
> > gpio_request(), + * but I don't know how to do this from outside of the
> > driver. */ + /* gpio_export(AMS_DELTA_GPIO_PIN_HOOK_SWITCH, 0); */
> > }
> >
> > static void __init ams_delta_map_io(void)
>
> J.