Date:   Wed, 8 Feb 2017 11:10:27 +0000
From:   Lee Jones <lee.jones@...aro.org>
To:     Thierry Escande <thierry.escande@...labora.com>
Cc:     linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2] mfd: cros_ec: Add ACPI GPE handler for LID0 devices

On Wed, 01 Feb 2017, 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>
> ---
> 
> This patch depends on https://lkml.org/lkml/2017/1/13/446
> 
> v2:
> - Sent as a separate patch as the other patches from the v1 patchset
>   have already been merged.
> - Moved ACPI specific APIs in a specific file so it's compiled only if
>   CONFIG_ACPI is enabled.
> 
>  drivers/mfd/Makefile           |   4 +-
>  drivers/mfd/cros_ec.c          |  15 ++++--
>  drivers/mfd/cros_ec_acpi_gpe.c | 103 +++++++++++++++++++++++++++++++++++++++++
>  include/linux/mfd/cros_ec.h    |  18 +++++++
>  4 files changed, 136 insertions(+), 4 deletions(-)
>  create mode 100644 drivers/mfd/cros_ec_acpi_gpe.c

Applied, thanks.

> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> index dda4d4f..7f48c00 100644
> --- a/drivers/mfd/Makefile
> +++ b/drivers/mfd/Makefile
> @@ -10,7 +10,9 @@ obj-$(CONFIG_MFD_ACT8945A)	+= act8945a.o
>  obj-$(CONFIG_MFD_SM501)		+= sm501.o
>  obj-$(CONFIG_MFD_ASIC3)		+= asic3.o tmio_core.o
>  obj-$(CONFIG_MFD_BCM590XX)	+= bcm590xx.o
> -obj-$(CONFIG_MFD_CROS_EC)	+= cros_ec.o
> +cros_ec_core-objs		:= cros_ec.o
> +cros_ec_core-$(CONFIG_ACPI)	+= cros_ec_acpi_gpe.o
> +obj-$(CONFIG_MFD_CROS_EC)	+= cros_ec_core.o
>  obj-$(CONFIG_MFD_CROS_EC_I2C)	+= cros_ec_i2c.o
>  obj-$(CONFIG_MFD_CROS_EC_SPI)	+= cros_ec_spi.o
>  obj-$(CONFIG_MFD_EXYNOS_LPASS)	+= exynos-lpass.o
> diff --git a/drivers/mfd/cros_ec.c b/drivers/mfd/cros_ec.c
> index 9b66a98..d4a407e 100644
> --- a/drivers/mfd/cros_ec.c
> +++ b/drivers/mfd/cros_ec.c
> @@ -166,6 +166,8 @@ int cros_ec_register(struct cros_ec_device *ec_dev)
>  
>  	dev_info(dev, "Chrome EC device registered\n");
>  
> +	cros_ec_acpi_install_gpe_handler(dev);
> +
>  	return 0;
>  
>  fail_mfd:
> @@ -179,6 +181,8 @@ int cros_ec_remove(struct cros_ec_device *ec_dev)
>  {
>  	mfd_remove_devices(ec_dev->dev);
>  
> +	cros_ec_acpi_remove_gpe_handler();
> +
>  	return 0;
>  }
>  EXPORT_SYMBOL(cros_ec_remove);
> @@ -190,9 +194,14 @@ int cros_ec_suspend(struct cros_ec_device *ec_dev)
>  	int ret;
>  	u8 sleep_event;
>  
> -	sleep_event = (!IS_ENABLED(CONFIG_ACPI) || pm_suspend_via_firmware()) ?
> -		      HOST_SLEEP_EVENT_S3_RESUME :
> -		      HOST_SLEEP_EVENT_S0IX_RESUME;
> +	if (!IS_ENABLED(CONFIG_ACPI) || pm_suspend_via_firmware()) {
> +		sleep_event = HOST_SLEEP_EVENT_S3_SUSPEND;
> +	} else {
> +		sleep_event = HOST_SLEEP_EVENT_S0IX_SUSPEND;
> +
> +		/* Clearing the GPE status for any pending event */
> +		cros_ec_acpi_clear_gpe();
> +	}
>  
>  	ret = cros_ec_sleep_event(ec_dev, sleep_event);
>  	if (ret < 0)
> diff --git a/drivers/mfd/cros_ec_acpi_gpe.c b/drivers/mfd/cros_ec_acpi_gpe.c
> new file mode 100644
> index 0000000..56d305d
> --- /dev/null
> +++ b/drivers/mfd/cros_ec_acpi_gpe.c
> @@ -0,0 +1,103 @@
> +/*
> + * ChromeOS EC multi-function device
> + *
> + * Copyright (C) 2017 Google, Inc
> + *
> + * This software is licensed under the terms of the GNU General Public
> + * License version 2, as published by the Free Software Foundation, and
> + * may be copied, distributed, and modified under those terms.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + *
> + * The ChromeOS EC multi function device is used to mux all the requests
> + * to the EC device for its multiple features: keyboard controller,
> + * battery charging and regulator control, firmware update.
> + */
> +#include <linux/acpi.h>
> +
> +#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)
> +{
> +	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;
> +}
> +
> +int cros_ec_acpi_install_gpe_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;
> +}
> +
> +void cros_ec_acpi_remove_gpe_handler(void)
> +{
> +	acpi_status status;
> +
> +	if (ec_wake_gpe < 0)
> +		return;
> +
> +	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");
> +}
> +
> +void cros_ec_acpi_clear_gpe(void)
> +{
> +	if (ec_wake_gpe < 0)
> +		return;
> +
> +	acpi_clear_gpe(NULL, ec_wake_gpe);
> +}
> diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h
> index 7a01c94..b3d04de 100644
> --- a/include/linux/mfd/cros_ec.h
> +++ b/include/linux/mfd/cros_ec.h
> @@ -304,4 +304,22 @@ extern struct attribute_group cros_ec_attr_group;
>  extern struct attribute_group cros_ec_lightbar_attr_group;
>  extern struct attribute_group cros_ec_vbc_attr_group;
>  
> +/* ACPI GPE handler */
> +#ifdef CONFIG_ACPI
> +
> +int cros_ec_acpi_install_gpe_handler(struct device *dev);
> +void cros_ec_acpi_remove_gpe_handler(void);
> +void cros_ec_acpi_clear_gpe(void);
> +
> +#else /* CONFIG_ACPI */
> +
> +static inline int cros_ec_acpi_install_gpe_handler(struct device *dev)
> +{
> +	return -ENODEV;
> +}
> +static inline void cros_ec_acpi_remove_gpe_handler(void) {}
> +static inline void cros_ec_acpi_clear_gpe(void) {}
> +
> +#endif /* CONFIG_ACPI */
> +
>  #endif /* __LINUX_MFD_CROS_EC_H */

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
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