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

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Date:   Wed, 4 Jan 2017 18:17:29 +0100
From:   Thierry Escande <thierry.escande@...labora.com>
To:     Lee Jones <lee.jones@...aro.org>
Cc:     Benson Leung <bleung@...omium.org>, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 3/3] mfd: cros_ec: Add ACPI GPE handler for LID0 devices

Hi Lee,

On 04/01/2017 10:06, Lee Jones wrote:
> On Fri, 16 Dec 2016, Thierry Escande wrote:
>
>> From: Archana Patni <archana.patni@...el.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@...el.com>
>> Signed-off-by: Thierry Escande <thierry.escande@...labora.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.

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)
>