platform/x86: ideapad-laptop: Expose conservation mode switch

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.

Signed-off-by: Hao Wei Tee <angelsl@in04.sg>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

diff --git a/drivers/platform/x86/ideapad-laptop.c b/drivers/platform/x86/ideapad-laptop.c
index 603fc60509713dc818b5612d7b8f6eb6238a53dd..fe98d4ac0df37040c3da8ad470bf7a33c5477fbe 100644 (file)
--- a/drivers/platform/x86/ideapad-laptop.c
+++ b/drivers/platform/x86/ideapad-laptop.c
@@ -42,6 +42,8 @@
 
 #define IDEAPAD_RFKILL_DEV_NUM (3)
 
+#define BM_CONSERVATION_BIT (5)
+
 #define CFG_BT_BIT     (16)
 #define CFG_3G_BIT     (17)
 #define CFG_WIFI_BIT   (18)
@@ -54,6 +56,11 @@ static const char *const ideapad_wmi_fnesc_events[] = {
 };
 #endif
 
+enum {
+       BMCMD_CONSERVATION_ON = 3,
+       BMCMD_CONSERVATION_OFF = 5,
+};
+
 enum {
        VPCCMD_R_VPC1 = 0x10,
        VPCCMD_R_BL_MAX,
@@ -123,6 +130,23 @@ static int read_method_int(acpi_handle handle, const char *method, int *val)
        }
 }
 
+static int method_gbmd(acpi_handle handle, unsigned long *ret)
+{
+       int result, val;
+
+       result = read_method_int(handle, "GBMD", &val);
+       *ret = val;
+       return result;
+}
+
+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;
@@ -250,6 +274,13 @@ 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 (!method_gbmd(priv->adev->handle, &value)) {
+               seq_printf(s, "Conservation mode:\t%s(%lu)\n",
+                          test_bit(BM_CONSERVATION_BIT, &value) ? "On" : "Off",
+                          value);
+       }
 
        return 0;
 }
@@ -456,10 +487,45 @@ static ssize_t __maybe_unused touchpad_store(struct device *dev,
 
 static DEVICE_ATTR_RO(touchpad);
 
+static ssize_t conservation_mode_show(struct device *dev,
+                               struct device_attribute *attr,
+                               char *buf)
+{
+       struct ideapad_private *priv = dev_get_drvdata(dev);
+       unsigned long result;
+
+       if (method_gbmd(priv->adev->handle, &result))
+               return sprintf(buf, "-1\n");
+       return sprintf(buf, "%u\n", test_bit(BM_CONSERVATION_BIT, &result));
+}
+
+static ssize_t conservation_mode_store(struct device *dev,
+                                struct device_attribute *attr,
+                                const char *buf, size_t count)
+{
+       struct ideapad_private *priv = dev_get_drvdata(dev);
+       bool state;
+       int ret;
+
+       ret = kstrtobool(buf, &state);
+       if (ret)
+               return ret;
+
+       ret = method_sbmc(priv->adev->handle, state ?
+                                             BMCMD_CONSERVATION_ON :
+                                             BMCMD_CONSERVATION_OFF);
+       if (ret < 0)
+               return -EIO;
+       return count;
+}
+
+static DEVICE_ATTR_RW(conservation_mode);
+
 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 +543,9 @@ 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;