Re: [PATCH 3/3] mfd: cros_ec: Add ACPI GPE handler for LID0 devices

[Thierry Escande <thierry.escande@collabora.com>]

Hi Lee,

On 05/01/2017 08:54, Lee Jones wrote:
> On Wed, 04 Jan 2017, Thierry Escande wrote:
>
>> Hi Lee,
>>
>> On 04/01/2017 10:06, Lee Jones wrote:
>>> On Fri, 16 Dec 2016, Thierry Escande wrote:
>>>
>>>> From: Archana Patni <archana.patni@intel.com>
>>>>
>>>> This patch installs an ACPI GPE handler for LID0 ACPI device to indicate
>>>> ACPI core that this GPE should stay enabled for lid to work in suspend
>>>> to idle path.
>>>>
>>>> Signed-off-by: Archana Patni <archana.patni@intel.com>
>>>> Signed-off-by: Thierry Escande <thierry.escande@collabora.com>
>>>> ---
>>>>  drivers/mfd/cros_ec.c | 97 +++++++++++++++++++++++++++++++++++++++++++++++++--
>>>>  1 file changed, 95 insertions(+), 2 deletions(-)
>>>>
>>>> diff --git a/drivers/mfd/cros_ec.c b/drivers/mfd/cros_ec.c
>>>> index b8a5080..628718e 100644
>>>> --- a/drivers/mfd/cros_ec.c
>>>> +++ b/drivers/mfd/cros_ec.c
>>>> @@ -17,6 +17,9 @@
>>>>   * battery charging and regulator control, firmware update.
>>>>   */
>>>>
>>>> +#ifdef CONFIG_ACPI
>>>> +#include <linux/acpi.h>
>>>> +#endif
>>>
>>> Please don't place #ifery in C files.
>>>
>>>>  #include <linux/of_platform.h>
>>>>  #include <linux/interrupt.h>
>>>>  #include <linux/slab.h>
>>>> @@ -29,6 +32,73 @@
>>>>  #define CROS_EC_DEV_EC_INDEX 0
>>>>  #define CROS_EC_DEV_PD_INDEX 1
>>>>
>>>> +#ifdef CONFIG_ACPI
>>>
>>> Remove this.
>>>
>>>> +#define ACPI_LID_DEVICE      "LID0"
>>>> +
>>>> +static int ec_wake_gpe = -EINVAL;
>>>> +
>>>> +/*
>>>> + * This handler indicates to ACPI core that this GPE should stay enabled for
>>>> + * lid to work in suspend to idle path.
>>>> + */
>>>> +static u32 cros_ec_gpe_handler(acpi_handle gpe_device, u32 gpe_number,
>>>> +			       void *data)
>>>> +{
>>>> +	return ACPI_INTERRUPT_HANDLED | ACPI_REENABLE_GPE;
>>>> +}
>>>> +
>>>> +/*
>>>> + * Get ACPI GPE for LID0 device.
>>>> + */
>>>> +static int cros_ec_get_ec_wake_gpe(struct device *dev)
>>>> +{
>> If it's ok for you, I'll keep one #ifdef CONFIG_ACPI around the body of this
>> function. Otherwise it won't compile if CONFIG_ACPI is not set.
>
> Can you try placing:
>
> 	if (IS_ENABLED(CONFIG_ACPI))
>
> ... before the call to cros_ec_get_ec_wake_gpe() and see if the
> compiler will do-the-right-thing please?

With CONFIG_ACPI not defined, the acpi_dev structure is not defined as 
well as the acpi_bus_get_device() API. So no, the compiler is not smart 
enough even if the function body is skipped by the test:
	if (!IS_ENABLED(CONFIG_ACPI))
		return -ENODEV;

Regards,
  Thierry

>>>> +	struct acpi_device *cros_acpi_dev;
>>>> +	struct acpi_device *adev;
>>>> +	acpi_handle handle;
>>>> +	acpi_status status;
>>>> +	int ret;
>>>> +
>>>> +	cros_acpi_dev = ACPI_COMPANION(dev);
>>>> +
>>>> +	if (!cros_acpi_dev || !cros_acpi_dev->parent ||
>>>> +	   !cros_acpi_dev->parent->handle)
>>>> +		return -EINVAL;
>>>> +
>>>> +	status = acpi_get_handle(cros_acpi_dev->parent->handle, ACPI_LID_DEVICE,
>>>> +				 &handle);
>>>> +	if (ACPI_FAILURE(status))
>>>> +		return -EINVAL;
>>>> +
>>>> +	ret = acpi_bus_get_device(handle, &adev);
>>>> +	if (ret)
>>>> +		return ret;
>>>> +
>>>> +	return adev->wakeup.gpe_number;
>>>> +}
>>>> +
>>>> +static int cros_ec_install_handler(struct device *dev)
>>>> +{
>>>> +	acpi_status status;
>>>> +
>>>> +	ec_wake_gpe = cros_ec_get_ec_wake_gpe(dev);
>>>> +
>>>> +	if (ec_wake_gpe < 0)
>>>> +		return ec_wake_gpe;
>>>> +
>>>> +	status = acpi_install_gpe_handler(NULL, ec_wake_gpe,
>>>> +					  ACPI_GPE_EDGE_TRIGGERED,
>>>> +					  &cros_ec_gpe_handler, NULL);
>>>> +	if (ACPI_FAILURE(status))
>>>> +		return -ENODEV;
>>>> +
>>>> +	dev_info(dev, "Initialized, GPE = 0x%x\n", ec_wake_gpe);
>>>> +
>>>> +	return 0;
>>>> +}
>>>> +
>>>> +#endif
>>>> +
>>>>  static struct cros_ec_platform ec_p = {
>>>>  	.ec_name = CROS_EC_DEV_NAME,
>>>>  	.cmd_offset = EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_EC_INDEX),
>>>> @@ -166,6 +236,10 @@ int cros_ec_register(struct cros_ec_device *ec_dev)
>>>>
>>>>  	dev_info(dev, "Chrome EC device registered\n");
>>>>
>>>> +#ifdef CONFIG_ACPI
>>>> +	cros_ec_install_handler(dev);
>>>> +#endif
>>>
>>> Here, just do:
>>>
>>> 	if (IS_ENABLED(CONFIG_ACPI))
>>> 		cros_ec_install_handler(dev);
>>>
>>> And let the compiler take care of the rest.
>>> 	
>>>>  	return 0;
>>>>
>>>>  fail_mfd:
>>>> @@ -179,6 +253,17 @@ int cros_ec_remove(struct cros_ec_device *ec_dev)
>>>>  {
>>>>  	mfd_remove_devices(ec_dev->dev);
>>>>
>>>> +#ifdef CONFIG_ACPI
>>>> +	if (ec_wake_gpe >= 0) {
>>>
>>> 	if (IS_ENABLED(CONFIG_ACPI) && ec_wake_gpe >= 0) {
>>>
>>>> +		acpi_status status;
>>>> +
>>>> +		status = acpi_remove_gpe_handler(NULL, ec_wake_gpe,
>>>> +						 &cros_ec_gpe_handler);
>>>> +		if (ACPI_FAILURE(status))
>>>> +			pr_err("failed to remove gpe handler\n");
>>>> +	}
>>>> +#endif
>>>> +
>>>>  	return 0;
>>>>  }
>>>>  EXPORT_SYMBOL(cros_ec_remove);
>>>> @@ -190,8 +275,16 @@ int cros_ec_suspend(struct cros_ec_device *ec_dev)
>>>>  	int ret;
>>>>  	u8 sleep_event;
>>>>
>>>> -	sleep_event = pm_suspend_via_firmware() ? HOST_SLEEP_EVENT_S3_RESUME :
>>>> -						  HOST_SLEEP_EVENT_S0IX_RESUME;
>>>> +	if (!pm_suspend_via_firmware()) {
>>>> +		sleep_event = HOST_SLEEP_EVENT_S0IX_SUSPEND;
>>>> +#ifdef CONFIG_ACPI
>>>> +		/* Clearing the GPE status for any pending event */
>>>> +		if (ec_wake_gpe >= 0)
>>>
>>> As above.
>>>
>>>> +			acpi_clear_gpe(NULL, ec_wake_gpe);
>>>> +#endif
>>>> +	} else {
>>>> +		sleep_event = HOST_SLEEP_EVENT_S3_SUSPEND;
>>>> +	}
>>>>
>>>>  	ret = cros_ec_sleep_event(ec_dev, sleep_event);
>>>>  	if (ret < 0)
>>>
>