linux-kernel - Re: [PATCH] platform/x86: ideapad-laptop: Expose conservation mode switch

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Date:   Sun, 28 May 2017 21:47:56 +0800
From:   Hao Wei Tee <angelsl@...elsl.xyz>
To:     platform-driver-x86@...r.kernel.org, linux-kernel@...r.kernel.org
Cc:     Andy Shevchenko <andy@...radead.org>,
        Darren Hart <dvhart@...radead.org>,
        Ike Panhc <ike.pan@...onical.com>
Subject: Re: [PATCH] platform/x86: ideapad-laptop: Expose conservation mode
 switch

On 5/27/17 3:31 PM, Hao Wei Tee wrote:
> This exposes the battery conservation mode present on some (?) IdeaPads.
> The mode is set by calling ACPI method SBMC with argument 3 (on) or
> 5 (off). Status is reported in bit 5 of the return value of ACPI method
> GBMD.
> 
> This patch was written based on an IdeaPad U430p. I'm not sure if the ACPI
> methods are the same across all IdeaPads, so it would be great if this got more
> testing across other models before it's merged.

I got someone to test on an IdeaPad Y510p. It works on that too.

> Signed-off-by: Hao Wei Tee <angelsl@...elsl.xyz>
> ---
>  drivers/platform/x86/ideapad-laptop.c | 70 +++++++++++++++++++++++++++++++++++
>  1 file changed, 70 insertions(+)
> 
> diff --git a/drivers/platform/x86/ideapad-laptop.c b/drivers/platform/x86/ideapad-laptop.c
> index d48962569364..3798a1ab1604 100644
> --- a/drivers/platform/x86/ideapad-laptop.c
> +++ b/drivers/platform/x86/ideapad-laptop.c
> @@ -42,6 +42,7 @@
>  
>  #define IDEAPAD_RFKILL_DEV_NUM	(3)
>  
> +#define GBMD_CONSERVATION_BIT (5)
>  #define CFG_BT_BIT	(16)
>  #define CFG_3G_BIT	(17)
>  #define CFG_WIFI_BIT	(18)
> @@ -55,6 +56,8 @@ static const char *const ideapad_wmi_fnesc_events[] = {
>  #endif
>  
>  enum {
> +	VPCCMD_CONSERVATION_ON = 3,
> +	VPCCMD_CONSERVATION_OFF = 5,
>  	VPCCMD_R_VPC1 = 0x10,
>  	VPCCMD_R_BL_MAX,
>  	VPCCMD_R_BL,
> @@ -123,6 +126,27 @@ static int read_method_int(acpi_handle handle, const char *method, int *val)
>  	}
>  }
>  
> +static int conservation_mode_status(acpi_handle handle, bool *ret)
> +{
> +	acpi_status status;
> +	unsigned long long result;
> +
> +	status = acpi_evaluate_integer(handle, "GBMD", NULL, &result);
> +	if (ACPI_FAILURE(status))
> +		return -1;
> +
> +	*ret = (result & (1 << GBMD_CONSERVATION_BIT)) != 0;
> +	return 0;
> +}
> +
> +static int method_sbmc(acpi_handle handle, int cmd)
> +{
> +	acpi_status status;
> +
> +	status = acpi_execute_simple_method(handle, "SBMC", cmd);
> +	return ACPI_FAILURE(status) ? -1 : 0;
> +}
> +
>  static int method_vpcr(acpi_handle handle, int cmd, int *ret)
>  {
>  	acpi_status status;
> @@ -218,6 +242,7 @@ static int debugfs_status_show(struct seq_file *s, void *data)
>  {
>  	struct ideapad_private *priv = s->private;
>  	unsigned long value;
> +	bool boolval;
>  
>  	if (!priv)
>  		return -EINVAL;
> @@ -250,6 +275,12 @@ static int debugfs_status_show(struct seq_file *s, void *data)
>  	if (!read_ec_data(priv->adev->handle, VPCCMD_R_CAMERA, &value))
>  		seq_printf(s, "Camera status:\t%s(%lu)\n",
>  			   value ? "On" : "Off", value);
> +	seq_puts(s, "=====================\n");
> +
> +	if (!conservation_mode_status(priv->adev->handle, &boolval)) {
> +		seq_printf(s, "Conservation mode:\t%s(%u)\n",
> +			   boolval ? "On" : "Off", boolval);
> +	}
>  
>  	return 0;
>  }
> @@ -456,10 +487,46 @@ static ssize_t __maybe_unused touchpad_store(struct device *dev,
>  
>  static DEVICE_ATTR_RO(touchpad);
>  
> +static ssize_t show_ideapad_conservation(struct device *dev,
> +				struct device_attribute *attr,
> +				char *buf)
> +{
> +	bool result;
> +	struct ideapad_private *priv = dev_get_drvdata(dev);
> +
> +	if (conservation_mode_status(priv->adev->handle, &result))
> +		return sprintf(buf, "-1\n");
> +	return sprintf(buf, "%u\n", result);
> +}
> +
> +static ssize_t store_ideapad_conservation(struct device *dev,
> +				 struct device_attribute *attr,
> +				 const char *buf, size_t count)
> +{
> +	int ret;
> +	bool state;
> +	struct ideapad_private *priv = dev_get_drvdata(dev);
> +
> +	ret = kstrtobool(buf, &state);
> +	if (ret)
> +		return ret;
> +
> +	ret = method_sbmc(priv->adev->handle, state ?
> +					      VPCCMD_CONSERVATION_ON :
> +					      VPCCMD_CONSERVATION_OFF);
> +	if (ret < 0)
> +		return -EIO;
> +	return count;
> +}
> +
> +static DEVICE_ATTR(conservation_mode, 0644, show_ideapad_conservation,
> +					    store_ideapad_conservation);
> +
>  static struct attribute *ideapad_attributes[] = {
>  	&dev_attr_camera_power.attr,
>  	&dev_attr_fan_mode.attr,
>  	&dev_attr_touchpad.attr,
> +	&dev_attr_conservation_mode.attr,
>  	NULL
>  };
>  
> @@ -477,6 +544,9 @@ static umode_t ideapad_is_visible(struct kobject *kobj,
>  		unsigned long value;
>  		supported = !read_ec_data(priv->adev->handle, VPCCMD_R_FAN,
>  					  &value);
> +	} else if (attr == &dev_attr_conservation_mode.attr) {
> +		supported = acpi_has_method(priv->adev->handle, "GBMD") &&
> +			    acpi_has_method(priv->adev->handle, "SBMC");
>  	} else
>  		supported = true;
>  
>