sony-laptop: support battery care functions

Allows limiting the maximum battery charge level to a selectable value
(100%, 80% and 50%).

[malattia@linux.it: group function specific variables in a struct, use
kstrtoul. Allow 0 to 100 values into sysfs files rounding to the actual
limit.]

Signed-off-by: Marco Chiappero <marco@absence.it>
Signed-off-by: Mattia Dongili <malattia@linux.it>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

diff --git a/drivers/platform/x86/sony-laptop.c b/drivers/platform/x86/sony-laptop.c
index 89e5cf9b1914999e0252b72ec14c1fb1a2dcd6f0..0ac186e9abdc89c4079cc91ec41ce011cac7f67f 100644 (file)
--- a/drivers/platform/x86/sony-laptop.c
+++ b/drivers/platform/x86/sony-laptop.c
@@ -144,6 +144,10 @@ static void sony_nc_kbd_backlight_resume(void);
 static void sony_nc_kbd_backlight_setup(struct platform_device *pd);
 static int sony_nc_kbd_backlight_cleanup(struct platform_device *pd);
 
+static int sony_nc_battery_care_setup(struct platform_device *pd,
+               unsigned int handle);
+static void sony_nc_battery_care_cleanup(struct platform_device *pd);
+
 enum sony_nc_rfkill {
        SONY_WIFI,
        SONY_BLUETOOTH,
@@ -1270,6 +1274,14 @@ static void sony_nc_function_setup(struct acpi_device *device,
                        /* setup hotkeys */
                        sony_call_snc_handle(handle, 0x100, &result);
                        break;
+               case 0x0115:
+               case 0x0136:
+               case 0x013f:
+                       result = sony_nc_battery_care_setup(pf_device, handle);
+                       if (result)
+                               pr_err("couldn't set up battery care function (%d)\n",
+                                               result);
+                       break;
                case 0x0124:
                case 0x0135:
                        sony_nc_rfkill_setup(device);
@@ -1306,6 +1318,11 @@ static void sony_nc_function_cleanup(struct platform_device *pd)
                        continue;
 
                switch (handle) {
+               case 0x0115:
+               case 0x0136:
+               case 0x013f:
+                       sony_nc_battery_care_cleanup(pd);
+                       break;
                case 0x0124:
                case 0x0135:
                        sony_nc_rfkill_cleanup();
@@ -1745,6 +1762,167 @@ static void sony_nc_kbd_backlight_resume(void)
                                &ignore);
 }
 
+struct battery_care_control {
+       struct device_attribute attrs[2];
+       unsigned int handle;
+};
+static struct battery_care_control *bcare_ctl;
+
+static ssize_t sony_nc_battery_care_limit_store(struct device *dev,
+               struct device_attribute *attr,
+               const char *buffer, size_t count)
+{
+       unsigned int result, cmd;
+       unsigned long value;
+
+       if (count > 31)
+               return -EINVAL;
+
+       if (kstrtoul(buffer, 10, &value))
+               return -EINVAL;
+
+       /*  limit values (2 bits):
+        *  00 - none
+        *  01 - 80%
+        *  10 - 50%
+        *  11 - 100%
+        *
+        *  bit 0: 0 disable BCL, 1 enable BCL
+        *  bit 1: 1 tell to store the battery limit (see bits 6,7) too
+        *  bits 2,3: reserved
+        *  bits 4,5: store the limit into the EC
+        *  bits 6,7: store the limit into the battery
+        */
+
+       /*
+        * handle 0x0115 should allow storing on battery too;
+        * handle 0x0136 same as 0x0115 + health status;
+        * handle 0x013f, same as 0x0136 but no storing on the battery
+        *
+        * Store only inside the EC for now, regardless the handle number
+        */
+       if (value == 0)
+               /* disable limits */
+               cmd = 0x0;
+
+       else if (value <= 50)
+               cmd = 0x21;
+
+       else if (value <= 80)
+               cmd = 0x11;
+
+       else if (value <= 100)
+               cmd = 0x31;
+
+       else
+               return -EINVAL;
+
+       if (sony_call_snc_handle(bcare_ctl->handle, (cmd << 0x10) | 0x0100,
+                               &result))
+               return -EIO;
+
+       return count;
+}
+
+static ssize_t sony_nc_battery_care_limit_show(struct device *dev,
+               struct device_attribute *attr, char *buffer)
+{
+       unsigned int result, status;
+
+       if (sony_call_snc_handle(bcare_ctl->handle, 0x0000, &result))
+               return -EIO;
+
+       status = (result & 0x01) ? ((result & 0x30) >> 0x04) : 0;
+       switch (status) {
+       case 1:
+               status = 80;
+               break;
+       case 2:
+               status = 50;
+               break;
+       case 3:
+               status = 100;
+               break;
+       default:
+               status = 0;
+               break;
+       }
+
+       return snprintf(buffer, PAGE_SIZE, "%d\n", status);
+}
+
+static ssize_t sony_nc_battery_care_health_show(struct device *dev,
+               struct device_attribute *attr, char *buffer)
+{
+       ssize_t count = 0;
+       unsigned int health;
+
+       if (sony_call_snc_handle(bcare_ctl->handle, 0x0200, &health))
+               return -EIO;
+
+       count = snprintf(buffer, PAGE_SIZE, "%d\n", health & 0xff);
+
+       return count;
+}
+
+static int sony_nc_battery_care_setup(struct platform_device *pd,
+               unsigned int handle)
+{
+       int ret = 0;
+
+       bcare_ctl = kzalloc(sizeof(struct battery_care_control), GFP_KERNEL);
+       if (!bcare_ctl)
+               return -ENOMEM;
+
+       bcare_ctl->handle = handle;
+
+       sysfs_attr_init(&bcare_ctl->attrs[0].attr);
+       bcare_ctl->attrs[0].attr.name = "battery_care_limiter";
+       bcare_ctl->attrs[0].attr.mode = S_IRUGO | S_IWUSR;
+       bcare_ctl->attrs[0].show = sony_nc_battery_care_limit_show;
+       bcare_ctl->attrs[0].store = sony_nc_battery_care_limit_store;
+
+       ret = device_create_file(&pd->dev, &bcare_ctl->attrs[0]);
+       if (ret)
+               goto outkzalloc;
+
+       /* 0x0115 is for models with no health reporting capability */
+       if (handle == 0x0115)
+               return 0;
+
+       sysfs_attr_init(&bcare_ctl->attrs[1].attr);
+       bcare_ctl->attrs[1].attr.name = "battery_care_health";
+       bcare_ctl->attrs[1].attr.mode = S_IRUGO;
+       bcare_ctl->attrs[1].show = sony_nc_battery_care_health_show;
+
+       ret = device_create_file(&pd->dev, &bcare_ctl->attrs[1]);
+       if (ret)
+               goto outlimiter;
+
+       return 0;
+
+outlimiter:
+       device_remove_file(&pd->dev, &bcare_ctl->attrs[0]);
+
+outkzalloc:
+       kfree(bcare_ctl);
+       bcare_ctl = NULL;
+
+       return ret;
+}
+
+static void sony_nc_battery_care_cleanup(struct platform_device *pd)
+{
+       if (bcare_ctl) {
+               device_remove_file(&pd->dev, &bcare_ctl->attrs[0]);
+               if (bcare_ctl->handle != 0x0115)
+                       device_remove_file(&pd->dev, &bcare_ctl->attrs[1]);
+
+               kfree(bcare_ctl);
+               bcare_ctl = NULL;
+       }
+}
+
 static void sony_nc_backlight_ng_read_limits(int handle,
                struct sony_backlight_props *props)
 {