Re: [PATCH v6] platform/x86: Add driver for ACPI INT0002 Virtual GPIO device

[Hans de Goede <hdegoede@redhat.com>]

Hi,

On 09-06-17 11:18, Andy Shevchenko wrote:
> On Fri, 2017-06-09 at 11:02 +0200, Linus Walleij wrote:
>> On Fri, Jun 2, 2017 at 5:15 PM, Hans de Goede <hdegoede@redhat.com>
>> wrote:
>>
>>> Some peripherals on Bay Trail and Cherry Trail platforms signal a
>>> Power Management Event (PME) to the Power Management Controller
>>> (PMC)
>>> to wakeup the system. When this happens software needs to explicitly
>>> clear the PME bus 0 status bit in the GPE0a_STS register to avoid an
>>> IRQ storm on IRQ 9.
>>>
>>> This is modelled in ACPI through the INT0002 ACPI device, which is
>>> called a "Virtual GPIO controller" in ACPI because it defines the
>>> event handler to call when the PME triggers through _AEI and _L02
>>> methods as would be done for a real GPIO interrupt in ACPI.
>>>
>>> This commit adds a driver which registers the Virtual GPIOs expected
>>> by the DSDT on these devices, letting gpiolib-acpi claim the
>>> virtual GPIO and install a GPIO-interrupt handler which call the
>>> _L02
>>> handler as it would for a real GPIO controller.
>>>
>>> Cc: joeyli <jlee@suse.com>
>>> Cc: Takashi Iwai <tiwai@suse.de>
>>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>>> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
>>> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
>>> ---
>>> Changes in v2:
>>> -Remove dev_err after malloc failure
>>> -Remove unused empty runtime pm callbacks
>>> -s/GPE0A_PME_/GPE0A_PME_B0_/
>>> -Fixed some checkpatch warnings (I forgot to run checkpatch on v1)
>>> Changes in v3:
>>> -Rewrite as gpiochip driver letting gpiolib-acpi deal with claiming
>>> the pin
>>>   0x0002 and calling the _L02 event handler when the virtual gpio-irq
>>> triggers
>>> -Rebase on 4.12-rc1
>>> Changes in v4:
>>> -Drop device_init_wakeup() from _probe(), use pm_system_wakeup()
>>> instead
>>>   of pm_wakeup_hard_event(chip->parent)
>>> -Improve commit message
>>> Changes in v5:
>>> -Use BIT() macro for FOO_BIT defines
>>> -Drop unneeded ACPI_PTR macro usage
>>> Changes in v6:
>>> -Move back to drivers/platform/x86
>>> -Expand certain acronyms (PME, PMC)
>>> -Use linux/gpio/driver.h include instead of linux/gpio.h
>>> -Document why the get / set / direction_output functions are dummys
>>> -No functional changes
>>
>> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
>>
>> With Andy's changes.
> 
> Oops, when I removed this from PDx86 testing branch I removed my changes
> together.
> 
> Here they are (Hans, perhaps you may resend with them included)

Ok, v7 with these and Linus' Reviewed-by added coming up.

Regards,

Hans



> --- a/drivers/platform/x86/intel_int0002_vgpio.c
> +++ b/drivers/platform/x86/intel_int0002_vgpio.c
> @@ -30,9 +30,8 @@
>    * for a real GPIO controller.
>    */
> 
> -#include <asm/cpu_device_id.h>
> -#include <asm/intel-family.h>
>   #include <linux/acpi.h>
> +#include <linux/bitmap.h>
>   #include <linux/gpio/driver.h>
>   #include <linux/interrupt.h>
>   #include <linux/io.h>
> @@ -42,6 +41,9 @@
>   #include <linux/slab.h>
>   #include <linux/suspend.h>
> 
> +#include <asm/cpu_device_id.h>
> +#include <asm/intel-family.h>
> +
>   #define DRV_NAME                       "INT0002 Virtual GPIO"
> 
>   /* For some reason the virtual GPIO pin tied to the GPE is numbered pin
> 2 */
> @@ -66,7 +68,7 @@ static const struct x86_cpu_id int0002_cpu_ids[] = {
> 
>   /*
>    * As this is not a real GPIO at all, but just a hack to model an event
> in
> - * APCI the get / set functions are dummy functions.
> + * ACPI the get / set functions are dummy functions.
>    */
> 
>   static int int0002_gpio_get(struct gpio_chip *chip, unsigned int
> offset)
> @@ -137,7 +139,7 @@ static int int0002_probe(struct platform_device
> *pdev)
>          struct device *dev = &pdev->dev;
>          const struct x86_cpu_id *cpu_id;
>          struct gpio_chip *chip;
> -       int i, irq, ret;
> +       int irq, ret;
> 
>          /* Menlow has a different INT0002 device? <sigh> */
>          cpu_id = x86_match_cpu(int0002_cpu_ids);
> @@ -171,8 +173,7 @@ static int int0002_probe(struct platform_device
> *pdev)
>                  return ret;
>          }
> 
> -       for (i = 0; i < GPE0A_PME_B0_VIRT_GPIO_PIN; i++)
> -               clear_bit(i, chip->irq_valid_mask);
> +       bitmap_clear(chip->irq_valid_mask, 0,
> GPE0A_PME_B0_VIRT_GPIO_PIN);
> 
>          /*
>           * We manually request the irq here instead of passing a flow-
> handler
> 
>>
>> Please feel free to push this upstream through the platform tree
>> or similar.
>>
>> Yours,
>> Linus Walleij
>