samsung-laptop: add battery life extender support (cb5b5c91) · Commits · e / devices / android_kernel_fairphone_FP3

Documentation/ABI/testing/sysfs-driver-samsung-laptop

+10 −0

Original line number	Diff line number	Diff line
		@@ -17,3 +17,13 @@ Description: Some Samsung laptops have different "performance levels"
		Specifically, not all support the "overclock" option,
		and it's still unknown if this value even changes
		anything, other than making the user feel a bit better.

		What: /sys/devices/platform/samsung/battery_life_extender
		Date: December 1, 2011
		KernelVersion: 3.3
		Contact: Corentin Chary <corentin.chary@gmail.com>
		Description: Max battery charge level can be modified, battery cycle
		life can be extended by reducing the max battery charge
		level.
		0 means normal battery mode (100% charge)
		1 means battery life extender mode (80% charge)

drivers/platform/x86/samsung-laptop.c

+82 −0

Original line number	Diff line number	Diff line
		@@ -104,6 +104,10 @@ struct sabi_commands {
		u16 get_performance_level;
		u16 set_performance_level;

		/* 0x80 is off, 0x81 is on */
		u16 get_battery_life_extender;
		u16 set_battery_life_extender;

		/*
		* Tell the BIOS that Linux is running on this machine.
		* 81 is on, 80 is off
		@@ -157,6 +161,9 @@ static const struct sabi_config sabi_configs[] = {
		.get_performance_level = 0x08,
		.set_performance_level = 0x09,

		.get_battery_life_extender = 0xFFFF,
		.set_battery_life_extender = 0xFFFF,

		.set_linux = 0x0a,
		},

		@@ -204,6 +211,9 @@ static const struct sabi_config sabi_configs[] = {
		.get_performance_level = 0x31,
		.set_performance_level = 0x32,

		.get_battery_life_extender = 0x65,
		.set_battery_life_extender = 0x66,

		.set_linux = 0xff,
		},

		@@ -543,8 +553,78 @@ static ssize_t set_performance_level(struct device *dev,
		static DEVICE_ATTR(performance_level, S_IWUSR \| S_IRUGO,
		get_performance_level, set_performance_level);

		static int read_battery_life_extender(struct samsung_laptop *samsung)
		{
		const struct sabi_commands *commands = &samsung->config->commands;
		struct sabi_data data;
		int retval;

		if (commands->get_battery_life_extender == 0xFFFF)
		return -ENODEV;

		memset(&data, 0, sizeof(data));
		data.data[0] = 0x80;
		retval = sabi_command(samsung, commands->get_battery_life_extender,
		&data, &data);

		if (retval)
		return retval;

		if (data.data[0] != 0 && data.data[0] != 1)
		return -ENODEV;

		return data.data[0];
		}

		static int write_battery_life_extender(struct samsung_laptop *samsung,
		int enabled)
		{
		const struct sabi_commands *commands = &samsung->config->commands;
		struct sabi_data data;

		memset(&data, 0, sizeof(data));
		data.data[0] = 0x80 \| enabled;
		return sabi_command(samsung, commands->set_battery_life_extender,
		&data, NULL);
		}

		static ssize_t get_battery_life_extender(struct device *dev,
		struct device_attribute *attr,
		char *buf)
		{
		struct samsung_laptop *samsung = dev_get_drvdata(dev);
		int ret;

		ret = read_battery_life_extender(samsung);
		if (ret < 0)
		return ret;

		return sprintf(buf, "%d\n", ret);
		}

		static ssize_t set_battery_life_extender(struct device *dev,
		struct device_attribute *attr,
		const char *buf, size_t count)
		{
		struct samsung_laptop *samsung = dev_get_drvdata(dev);
		int ret, value;

		if (!count \|\| sscanf(buf, "%i", &value) != 1)
		return -EINVAL;

		ret = write_battery_life_extender(samsung, !!value);
		if (ret < 0)
		return ret;

		return count;
		}

		static DEVICE_ATTR(battery_life_extender, S_IWUSR \| S_IRUGO,
		get_battery_life_extender, set_battery_life_extender);

		static struct attribute *platform_attributes[] = {
		&dev_attr_performance_level.attr,
		&dev_attr_battery_life_extender.attr,
		NULL
		};

		@@ -643,6 +723,8 @@ static mode_t samsung_sysfs_is_visible(struct kobject *kobj,

		if (attr == &dev_attr_performance_level.attr)
		ok = !!samsung->config->performance_levels[0].name;
		if (attr == &dev_attr_battery_life_extender.attr)
		ok = !!(read_battery_life_extender(samsung) >= 0);

		return ok ? attr->mode : 0;
		}