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

[Lee Jones <lee.jones@linaro.org>]

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?

> > > +	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)
> > 

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog