linux-kernel - Re: [PATCH 2/3] mfd: cros_ec: Send suspend state notification to EC

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Date:   Wed, 4 Jan 2017 09:07:07 +0000
From:   Lee Jones <lee.jones@...aro.org>
To:     Thierry Escande <thierry.escande@...labora.com>
Cc:     Benson Leung <bleung@...omium.org>, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2/3] mfd: cros_ec: Send suspend state notification to EC

On Fri, 16 Dec 2016, Thierry Escande wrote:

> From: Shawn Nematbakhsh <shawnn@...omium.org>
> 
> Notify EC when going to or returning from suspend so that proper actions
> related to wake events can be taken.
> 
> Signed-off-by: Shawn Nematbakhsh <shawnn@...omium.org>
> Signed-off-by: Thierry Escande <thierry.escande@...labora.com>
> ---
>  drivers/mfd/cros_ec.c                | 49 ++++++++++++++++++++++++++++++++++++
>  include/linux/mfd/cros_ec_commands.h | 14 +++++++++++
>  2 files changed, 63 insertions(+)

Can this patch be taken without 3/3?

For my own reference:
  Acked-for-MFD-by: Lee Jones <lee.jones@...aro.org>

> diff --git a/drivers/mfd/cros_ec.c b/drivers/mfd/cros_ec.c
> index ad48633..b8a5080 100644
> --- a/drivers/mfd/cros_ec.c
> +++ b/drivers/mfd/cros_ec.c
> @@ -23,6 +23,7 @@
>  #include <linux/module.h>
>  #include <linux/mfd/core.h>
>  #include <linux/mfd/cros_ec.h>
> +#include <linux/suspend.h>
>  #include <asm/unaligned.h>
>  
>  #define CROS_EC_DEV_EC_INDEX 0
> @@ -65,6 +66,24 @@ static irqreturn_t ec_irq_thread(int irq, void *data)
>  	return IRQ_HANDLED;
>  }
>  
> +static int cros_ec_sleep_event(struct cros_ec_device *ec_dev, u8 sleep_event)
> +{
> +	struct {
> +		struct cros_ec_command msg;
> +		struct ec_params_host_sleep_event req;
> +	} __packed buf;
> +
> +	memset(&buf, 0, sizeof(buf));
> +
> +	buf.req.sleep_event = sleep_event;
> +
> +	buf.msg.command = EC_CMD_HOST_SLEEP_EVENT;
> +	buf.msg.version = 0;
> +	buf.msg.outsize = sizeof(buf.req);
> +
> +	return cros_ec_cmd_xfer(ec_dev, &buf.msg);
> +}
> +
>  int cros_ec_register(struct cros_ec_device *ec_dev)
>  {
>  	struct device *dev = ec_dev->dev;
> @@ -136,6 +155,15 @@ int cros_ec_register(struct cros_ec_device *ec_dev)
>  		}
>  	}
>  
> +	/*
> +	 * Clear sleep event - this will fail harmlessly on platforms that
> +	 * don't implement the sleep event host command.
> +	 */
> +	err = cros_ec_sleep_event(ec_dev, 0);
> +	if (err < 0)
> +		dev_dbg(ec_dev->dev, "Error %d clearing sleep event to ec",
> +			err);
> +
>  	dev_info(dev, "Chrome EC device registered\n");
>  
>  	return 0;
> @@ -159,6 +187,16 @@ EXPORT_SYMBOL(cros_ec_remove);
>  int cros_ec_suspend(struct cros_ec_device *ec_dev)
>  {
>  	struct device *dev = ec_dev->dev;
> +	int ret;
> +	u8 sleep_event;
> +
> +	sleep_event = pm_suspend_via_firmware() ? HOST_SLEEP_EVENT_S3_RESUME :
> +						  HOST_SLEEP_EVENT_S0IX_RESUME;
> +
> +	ret = cros_ec_sleep_event(ec_dev, sleep_event);
> +	if (ret < 0)
> +		dev_dbg(ec_dev->dev, "Error %d sending suspend event to ec",
> +			ret);
>  
>  	if (device_may_wakeup(dev))
>  		ec_dev->wake_enabled = !enable_irq_wake(ec_dev->irq);
> @@ -180,9 +218,20 @@ static void cros_ec_drain_events(struct cros_ec_device *ec_dev)
>  
>  int cros_ec_resume(struct cros_ec_device *ec_dev)
>  {
> +	int ret;
> +	u8 sleep_event;
> +
>  	ec_dev->suspended = false;
>  	enable_irq(ec_dev->irq);
>  
> +	sleep_event = pm_suspend_via_firmware() ? HOST_SLEEP_EVENT_S3_RESUME :
> +						  HOST_SLEEP_EVENT_S0IX_RESUME;
> +
> +	ret = cros_ec_sleep_event(ec_dev, sleep_event);
> +	if (ret < 0)
> +		dev_dbg(ec_dev->dev, "Error %d sending resume event to ec",
> +			ret);
> +
>  	/*
>  	 * In some cases, we need to distinguish between events that occur
>  	 * during suspend if the EC is not a wake source. For example,
> diff --git a/include/linux/mfd/cros_ec_commands.h b/include/linux/mfd/cros_ec_commands.h
> index 76728ff..4d55132 100644
> --- a/include/linux/mfd/cros_ec_commands.h
> +++ b/include/linux/mfd/cros_ec_commands.h
> @@ -2304,6 +2304,20 @@ struct ec_params_ext_power_current_limit {
>  	uint32_t limit; /* in mA */
>  } __packed;
>  
> +/* Inform the EC when entering a sleep state */
> +#define EC_CMD_HOST_SLEEP_EVENT 0xa9
> +
> +enum host_sleep_event {
> +	HOST_SLEEP_EVENT_S3_SUSPEND   = 1,
> +	HOST_SLEEP_EVENT_S3_RESUME    = 2,
> +	HOST_SLEEP_EVENT_S0IX_SUSPEND = 3,
> +	HOST_SLEEP_EVENT_S0IX_RESUME  = 4
> +};
> +
> +struct ec_params_host_sleep_event {
> +	uint8_t sleep_event;
> +} __packed;
> +
>  /*****************************************************************************/
>  /* Smart battery pass-through */
>  

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