ACPI / Fan: add ACPI 4.0 style fan support

This patch adds support for ACPI 4.0 style fan, lacking part is: no
support for 'Low Speed Notification Support', 'Fine Grain Control' is
not used yet.

It's not clear what to do on suspend/resume callback for 4.0 style ACPI
fan, so it does nothing for now.

Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

1 files changed, 241 insertions, 27 deletions

diff --git a/drivers/acpi/fan.c b/drivers/acpi/fan.c
index 8a5b450576df..f7d1c8027736 100644
--- a/drivers/acpi/fan.c
+++ b/drivers/acpi/fan.c
@@ -31,6 +31,7 @@
 #include <linux/thermal.h>
 #include <linux/acpi.h>
 #include <linux/platform_device.h>
+#include <linux/sort.h>
 
 MODULE_AUTHOR("Paul Diefenbaugh");
 MODULE_DESCRIPTION("ACPI Fan Driver");
@@ -59,6 +60,29 @@ static struct dev_pm_ops acpi_fan_pm = {
 #define FAN_PM_OPS_PTR NULL
 #endif
 
+struct acpi_fan_fps {
+        u64 control;
+        u64 trip_point;
+        u64 speed;
+        u64 noise_level;
+        u64 power;
+};
+
+struct acpi_fan_fif {
+        u64 revision;
+        u64 fine_grain_ctrl;
+        u64 step_size;
+        u64 low_speed_notification;
+};
+
+struct acpi_fan {
+        bool acpi4;
+        struct acpi_fan_fif fif;
+        struct acpi_fan_fps *fps;
+        int fps_count;
+        struct thermal_cooling_device *cdev;
+};
+
 static struct platform_driver acpi_fan_driver = {
         .probe = acpi_fan_probe,
         .remove = acpi_fan_remove,
@@ -73,21 +97,62 @@ static struct platform_driver acpi_fan_driver = {
 static int fan_get_max_state(struct thermal_cooling_device *cdev, unsigned long
                              *state)
 {
-        /* ACPI fan device only support two states: ON/OFF */
-        *state = 1;
+        struct acpi_device *device = cdev->devdata;
+        struct acpi_fan *fan = acpi_driver_data(device);
+
+        if (fan->acpi4)
+                *state = fan->fps_count - 1;
+        else
+                *state = 1;
         return 0;
 }
 
-static int fan_get_cur_state(struct thermal_cooling_device *cdev, unsigned long
-                             *state)
+static int fan_get_state_acpi4(struct acpi_device *device, unsigned long *state)
+{
+        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+        struct acpi_fan *fan = acpi_driver_data(device);
+        union acpi_object *obj;
+        acpi_status status;
+        int control, i;
+
+        status = acpi_evaluate_object(device->handle, "_FST", NULL, &buffer);
+        if (ACPI_FAILURE(status)) {
+                dev_err(&device->dev, "Get fan state failed\n");
+                return status;
+        }
+
+        obj = buffer.pointer;
+        if (!obj || obj->type != ACPI_TYPE_PACKAGE ||
+            obj->package.count != 3 ||
+            obj->package.elements[1].type != ACPI_TYPE_INTEGER) {
+                dev_err(&device->dev, "Invalid _FST data\n");
+                status = -EINVAL;
+                goto err;
+        }
+
+        control = obj->package.elements[1].integer.value;
+        for (i = 0; i < fan->fps_count; i++) {
+                if (control == fan->fps[i].control)
+                        break;
+        }
+        if (i == fan->fps_count) {
+                dev_dbg(&device->dev, "Invalid control value returned\n");
+                status = -EINVAL;
+                goto err;
+        }
+
+        *state = i;
+
+err:
+        kfree(obj);
+        return status;
+}
+
+static int fan_get_state(struct acpi_device *device, unsigned long *state)
 {
-        struct acpi_device *device = cdev->devdata;
         int result;
         int acpi_state = ACPI_STATE_D0;
 
-        if (!device)
-                return -EINVAL;
-
         result = acpi_device_update_power(device, &acpi_state);
         if (result)
                 return result;
@@ -97,21 +162,57 @@ static int fan_get_cur_state(struct thermal_cooling_device *cdev, unsigned long
         return 0;
 }
 
-static int
-fan_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state)
+static int fan_get_cur_state(struct thermal_cooling_device *cdev, unsigned long
+                             *state)
 {
         struct acpi_device *device = cdev->devdata;
-        int result;
+        struct acpi_fan *fan = acpi_driver_data(device);
+
+        if (fan->acpi4)
+                return fan_get_state_acpi4(device, state);
+        else
+                return fan_get_state(device, state);
+}
 
-        if (!device || (state != 0 && state != 1))
+static int fan_set_state(struct acpi_device *device, unsigned long state)
+{
+        if (state != 0 && state != 1)
                 return -EINVAL;
 
-        result = acpi_device_set_power(device,
-                                state ? ACPI_STATE_D0 : ACPI_STATE_D3_COLD);
+        return acpi_device_set_power(device,
+                                     state ? ACPI_STATE_D0 : ACPI_STATE_D3_COLD);
+}
 
-        return result;
+static int fan_set_state_acpi4(struct acpi_device *device, unsigned long state)
+{
+        struct acpi_fan *fan = acpi_driver_data(device);
+        acpi_status status;
+
+        if (state >= fan->fps_count)
+                return -EINVAL;
+
+        status = acpi_execute_simple_method(device->handle, "_FSL",
+                                            fan->fps[state].control);
+        if (ACPI_FAILURE(status)) {
+                dev_dbg(&device->dev, "Failed to set state by _FSL\n");
+                return status;
+        }
+
+        return 0;
 }
 
+static int
+fan_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state)
+{
+        struct acpi_device *device = cdev->devdata;
+        struct acpi_fan *fan = acpi_driver_data(device);
+
+        if (fan->acpi4)
+                return fan_set_state_acpi4(device, state);
+        else
+                return fan_set_state(device, state);
+ }
+
 static const struct thermal_cooling_device_ops fan_cooling_ops = {
         .get_max_state = fan_get_max_state,
         .get_cur_state = fan_get_cur_state,
@@ -122,16 +223,125 @@ static const struct thermal_cooling_device_ops fan_cooling_ops = {
                                  Driver Interface
    -------------------------------------------------------------------------- */
 
+static bool acpi_fan_is_acpi4(struct acpi_device *device)
+{
+        return acpi_has_method(device->handle, "_FIF") &&
+               acpi_has_method(device->handle, "_FPS") &&
+               acpi_has_method(device->handle, "_FSL") &&
+               acpi_has_method(device->handle, "_FST");
+}
+
+static int acpi_fan_get_fif(struct acpi_device *device)
+{