These changes are the raw update to linux-4.4.6-rt14. Kernel sources
[kvmfornfv.git] / kernel / drivers / gpu / drm / amd / amdgpu / amdgpu_acpi.c
diff --git a/kernel/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c b/kernel/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c
new file mode 100644 (file)
index 0000000..a142d5a
--- /dev/null
@@ -0,0 +1,767 @@
+/*
+ * Copyright 2012 Advanced Micro Devices, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ */
+
+#include <linux/pci.h>
+#include <linux/acpi.h>
+#include <linux/slab.h>
+#include <linux/power_supply.h>
+#include <acpi/video.h>
+#include <drm/drmP.h>
+#include <drm/drm_crtc_helper.h>
+#include "amdgpu.h"
+#include "amdgpu_acpi.h"
+#include "atom.h"
+
+#define ACPI_AC_CLASS           "ac_adapter"
+
+extern void amdgpu_pm_acpi_event_handler(struct amdgpu_device *adev);
+
+struct atif_verify_interface {
+       u16 size;               /* structure size in bytes (includes size field) */
+       u16 version;            /* version */
+       u32 notification_mask;  /* supported notifications mask */
+       u32 function_bits;      /* supported functions bit vector */
+} __packed;
+
+struct atif_system_params {
+       u16 size;               /* structure size in bytes (includes size field) */
+       u32 valid_mask;         /* valid flags mask */
+       u32 flags;              /* flags */
+       u8 command_code;        /* notify command code */
+} __packed;
+
+struct atif_sbios_requests {
+       u16 size;               /* structure size in bytes (includes size field) */
+       u32 pending;            /* pending sbios requests */
+       u8 panel_exp_mode;      /* panel expansion mode */
+       u8 thermal_gfx;         /* thermal state: target gfx controller */
+       u8 thermal_state;       /* thermal state: state id (0: exit state, non-0: state) */
+       u8 forced_power_gfx;    /* forced power state: target gfx controller */
+       u8 forced_power_state;  /* forced power state: state id */
+       u8 system_power_src;    /* system power source */
+       u8 backlight_level;     /* panel backlight level (0-255) */
+} __packed;
+
+#define ATIF_NOTIFY_MASK       0x3
+#define ATIF_NOTIFY_NONE       0
+#define ATIF_NOTIFY_81         1
+#define ATIF_NOTIFY_N          2
+
+struct atcs_verify_interface {
+       u16 size;               /* structure size in bytes (includes size field) */
+       u16 version;            /* version */
+       u32 function_bits;      /* supported functions bit vector */
+} __packed;
+
+#define ATCS_VALID_FLAGS_MASK  0x3
+
+struct atcs_pref_req_input {
+       u16 size;               /* structure size in bytes (includes size field) */
+       u16 client_id;          /* client id (bit 2-0: func num, 7-3: dev num, 15-8: bus num) */
+       u16 valid_flags_mask;   /* valid flags mask */
+       u16 flags;              /* flags */
+       u8 req_type;            /* request type */
+       u8 perf_req;            /* performance request */
+} __packed;
+
+struct atcs_pref_req_output {
+       u16 size;               /* structure size in bytes (includes size field) */
+       u8 ret_val;             /* return value */
+} __packed;
+
+/* Call the ATIF method
+ */
+/**
+ * amdgpu_atif_call - call an ATIF method
+ *
+ * @handle: acpi handle
+ * @function: the ATIF function to execute
+ * @params: ATIF function params
+ *
+ * Executes the requested ATIF function (all asics).
+ * Returns a pointer to the acpi output buffer.
+ */
+static union acpi_object *amdgpu_atif_call(acpi_handle handle, int function,
+               struct acpi_buffer *params)
+{
+       acpi_status status;
+       union acpi_object atif_arg_elements[2];
+       struct acpi_object_list atif_arg;
+       struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+
+       atif_arg.count = 2;
+       atif_arg.pointer = &atif_arg_elements[0];
+
+       atif_arg_elements[0].type = ACPI_TYPE_INTEGER;
+       atif_arg_elements[0].integer.value = function;
+
+       if (params) {
+               atif_arg_elements[1].type = ACPI_TYPE_BUFFER;
+               atif_arg_elements[1].buffer.length = params->length;
+               atif_arg_elements[1].buffer.pointer = params->pointer;
+       } else {
+               /* We need a second fake parameter */
+               atif_arg_elements[1].type = ACPI_TYPE_INTEGER;
+               atif_arg_elements[1].integer.value = 0;
+       }
+
+       status = acpi_evaluate_object(handle, "ATIF", &atif_arg, &buffer);
+
+       /* Fail only if calling the method fails and ATIF is supported */
+       if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
+               DRM_DEBUG_DRIVER("failed to evaluate ATIF got %s\n",
+                                acpi_format_exception(status));
+               kfree(buffer.pointer);
+               return NULL;
+       }
+
+       return buffer.pointer;
+}
+
+/**
+ * amdgpu_atif_parse_notification - parse supported notifications
+ *
+ * @n: supported notifications struct
+ * @mask: supported notifications mask from ATIF
+ *
+ * Use the supported notifications mask from ATIF function
+ * ATIF_FUNCTION_VERIFY_INTERFACE to determine what notifications
+ * are supported (all asics).
+ */
+static void amdgpu_atif_parse_notification(struct amdgpu_atif_notifications *n, u32 mask)
+{
+       n->display_switch = mask & ATIF_DISPLAY_SWITCH_REQUEST_SUPPORTED;
+       n->expansion_mode_change = mask & ATIF_EXPANSION_MODE_CHANGE_REQUEST_SUPPORTED;
+       n->thermal_state = mask & ATIF_THERMAL_STATE_CHANGE_REQUEST_SUPPORTED;
+       n->forced_power_state = mask & ATIF_FORCED_POWER_STATE_CHANGE_REQUEST_SUPPORTED;
+       n->system_power_state = mask & ATIF_SYSTEM_POWER_SOURCE_CHANGE_REQUEST_SUPPORTED;
+       n->display_conf_change = mask & ATIF_DISPLAY_CONF_CHANGE_REQUEST_SUPPORTED;
+       n->px_gfx_switch = mask & ATIF_PX_GFX_SWITCH_REQUEST_SUPPORTED;
+       n->brightness_change = mask & ATIF_PANEL_BRIGHTNESS_CHANGE_REQUEST_SUPPORTED;
+       n->dgpu_display_event = mask & ATIF_DGPU_DISPLAY_EVENT_SUPPORTED;
+}
+
+/**
+ * amdgpu_atif_parse_functions - parse supported functions
+ *
+ * @f: supported functions struct
+ * @mask: supported functions mask from ATIF
+ *
+ * Use the supported functions mask from ATIF function
+ * ATIF_FUNCTION_VERIFY_INTERFACE to determine what functions
+ * are supported (all asics).
+ */
+static void amdgpu_atif_parse_functions(struct amdgpu_atif_functions *f, u32 mask)
+{
+       f->system_params = mask & ATIF_GET_SYSTEM_PARAMETERS_SUPPORTED;
+       f->sbios_requests = mask & ATIF_GET_SYSTEM_BIOS_REQUESTS_SUPPORTED;
+       f->select_active_disp = mask & ATIF_SELECT_ACTIVE_DISPLAYS_SUPPORTED;
+       f->lid_state = mask & ATIF_GET_LID_STATE_SUPPORTED;
+       f->get_tv_standard = mask & ATIF_GET_TV_STANDARD_FROM_CMOS_SUPPORTED;
+       f->set_tv_standard = mask & ATIF_SET_TV_STANDARD_IN_CMOS_SUPPORTED;
+       f->get_panel_expansion_mode = mask & ATIF_GET_PANEL_EXPANSION_MODE_FROM_CMOS_SUPPORTED;
+       f->set_panel_expansion_mode = mask & ATIF_SET_PANEL_EXPANSION_MODE_IN_CMOS_SUPPORTED;
+       f->temperature_change = mask & ATIF_TEMPERATURE_CHANGE_NOTIFICATION_SUPPORTED;
+       f->graphics_device_types = mask & ATIF_GET_GRAPHICS_DEVICE_TYPES_SUPPORTED;
+}
+
+/**
+ * amdgpu_atif_verify_interface - verify ATIF
+ *
+ * @handle: acpi handle
+ * @atif: amdgpu atif struct
+ *
+ * Execute the ATIF_FUNCTION_VERIFY_INTERFACE ATIF function
+ * to initialize ATIF and determine what features are supported
+ * (all asics).
+ * returns 0 on success, error on failure.
+ */
+static int amdgpu_atif_verify_interface(acpi_handle handle,
+               struct amdgpu_atif *atif)
+{
+       union acpi_object *info;
+       struct atif_verify_interface output;
+       size_t size;
+       int err = 0;
+
+       info = amdgpu_atif_call(handle, ATIF_FUNCTION_VERIFY_INTERFACE, NULL);
+       if (!info)
+               return -EIO;
+
+       memset(&output, 0, sizeof(output));
+
+       size = *(u16 *) info->buffer.pointer;
+       if (size < 12) {
+               DRM_INFO("ATIF buffer is too small: %zu\n", size);
+               err = -EINVAL;
+               goto out;
+       }
+       size = min(sizeof(output), size);
+
+       memcpy(&output, info->buffer.pointer, size);
+
+       /* TODO: check version? */
+       DRM_DEBUG_DRIVER("ATIF version %u\n", output.version);
+
+       amdgpu_atif_parse_notification(&atif->notifications, output.notification_mask);
+       amdgpu_atif_parse_functions(&atif->functions, output.function_bits);
+
+out:
+       kfree(info);
+       return err;
+}
+
+/**
+ * amdgpu_atif_get_notification_params - determine notify configuration
+ *
+ * @handle: acpi handle
+ * @n: atif notification configuration struct
+ *
+ * Execute the ATIF_FUNCTION_GET_SYSTEM_PARAMETERS ATIF function
+ * to determine if a notifier is used and if so which one
+ * (all asics).  This is either Notify(VGA, 0x81) or Notify(VGA, n)
+ * where n is specified in the result if a notifier is used.
+ * Returns 0 on success, error on failure.
+ */
+static int amdgpu_atif_get_notification_params(acpi_handle handle,
+               struct amdgpu_atif_notification_cfg *n)
+{
+       union acpi_object *info;
+       struct atif_system_params params;
+       size_t size;
+       int err = 0;
+
+       info = amdgpu_atif_call(handle, ATIF_FUNCTION_GET_SYSTEM_PARAMETERS, NULL);
+       if (!info) {
+               err = -EIO;
+               goto out;
+       }
+
+       size = *(u16 *) info->buffer.pointer;
+       if (size < 10) {
+               err = -EINVAL;
+               goto out;
+       }
+
+       memset(&params, 0, sizeof(params));
+       size = min(sizeof(params), size);
+       memcpy(&params, info->buffer.pointer, size);
+
+       DRM_DEBUG_DRIVER("SYSTEM_PARAMS: mask = %#x, flags = %#x\n",
+                       params.flags, params.valid_mask);
+       params.flags = params.flags & params.valid_mask;
+
+       if ((params.flags & ATIF_NOTIFY_MASK) == ATIF_NOTIFY_NONE) {
+               n->enabled = false;
+               n->command_code = 0;
+       } else if ((params.flags & ATIF_NOTIFY_MASK) == ATIF_NOTIFY_81) {
+               n->enabled = true;
+               n->command_code = 0x81;
+       } else {
+               if (size < 11) {
+                       err = -EINVAL;
+                       goto out;
+               }
+               n->enabled = true;
+               n->command_code = params.command_code;
+       }
+
+out:
+       DRM_DEBUG_DRIVER("Notification %s, command code = %#x\n",
+                       (n->enabled ? "enabled" : "disabled"),
+                       n->command_code);
+       kfree(info);
+       return err;
+}
+
+/**
+ * amdgpu_atif_get_sbios_requests - get requested sbios event
+ *
+ * @handle: acpi handle
+ * @req: atif sbios request struct
+ *
+ * Execute the ATIF_FUNCTION_GET_SYSTEM_BIOS_REQUESTS ATIF function
+ * to determine what requests the sbios is making to the driver
+ * (all asics).
+ * Returns 0 on success, error on failure.
+ */
+static int amdgpu_atif_get_sbios_requests(acpi_handle handle,
+               struct atif_sbios_requests *req)
+{
+       union acpi_object *info;
+       size_t size;
+       int count = 0;
+
+       info = amdgpu_atif_call(handle, ATIF_FUNCTION_GET_SYSTEM_BIOS_REQUESTS, NULL);
+       if (!info)
+               return -EIO;
+
+       size = *(u16 *)info->buffer.pointer;
+       if (size < 0xd) {
+               count = -EINVAL;
+               goto out;
+       }
+       memset(req, 0, sizeof(*req));
+
+       size = min(sizeof(*req), size);
+       memcpy(req, info->buffer.pointer, size);
+       DRM_DEBUG_DRIVER("SBIOS pending requests: %#x\n", req->pending);
+
+       count = hweight32(req->pending);
+
+out:
+       kfree(info);
+       return count;
+}
+
+/**
+ * amdgpu_atif_handler - handle ATIF notify requests
+ *
+ * @adev: amdgpu_device pointer
+ * @event: atif sbios request struct
+ *
+ * Checks the acpi event and if it matches an atif event,
+ * handles it.
+ * Returns NOTIFY code
+ */
+int amdgpu_atif_handler(struct amdgpu_device *adev,
+                       struct acpi_bus_event *event)
+{
+       struct amdgpu_atif *atif = &adev->atif;
+       struct atif_sbios_requests req;
+       acpi_handle handle;
+       int count;
+
+       DRM_DEBUG_DRIVER("event, device_class = %s, type = %#x\n",
+                       event->device_class, event->type);
+
+       if (strcmp(event->device_class, ACPI_VIDEO_CLASS) != 0)
+               return NOTIFY_DONE;
+
+       if (!atif->notification_cfg.enabled ||
+           event->type != atif->notification_cfg.command_code)
+               /* Not our event */
+               return NOTIFY_DONE;
+
+       /* Check pending SBIOS requests */
+       handle = ACPI_HANDLE(&adev->pdev->dev);
+       count = amdgpu_atif_get_sbios_requests(handle, &req);
+
+       if (count <= 0)
+               return NOTIFY_DONE;
+
+       DRM_DEBUG_DRIVER("ATIF: %d pending SBIOS requests\n", count);
+
+       if (req.pending & ATIF_PANEL_BRIGHTNESS_CHANGE_REQUEST) {
+               struct amdgpu_encoder *enc = atif->encoder_for_bl;
+
+               if (enc) {
+                       struct amdgpu_encoder_atom_dig *dig = enc->enc_priv;
+
+                       DRM_DEBUG_DRIVER("Changing brightness to %d\n",
+                                       req.backlight_level);
+
+                       amdgpu_display_backlight_set_level(adev, enc, req.backlight_level);
+
+#if defined(CONFIG_BACKLIGHT_CLASS_DEVICE) || defined(CONFIG_BACKLIGHT_CLASS_DEVICE_MODULE)
+                       backlight_force_update(dig->bl_dev,
+                                              BACKLIGHT_UPDATE_HOTKEY);
+#endif
+               }
+       }
+       /* TODO: check other events */
+
+       /* We've handled the event, stop the notifier chain. The ACPI interface
+        * overloads ACPI_VIDEO_NOTIFY_PROBE, we don't want to send that to
+        * userspace if the event was generated only to signal a SBIOS
+        * request.
+        */
+       return NOTIFY_BAD;
+}
+
+/* Call the ATCS method
+ */
+/**
+ * amdgpu_atcs_call - call an ATCS method
+ *
+ * @handle: acpi handle
+ * @function: the ATCS function to execute
+ * @params: ATCS function params
+ *
+ * Executes the requested ATCS function (all asics).
+ * Returns a pointer to the acpi output buffer.
+ */
+static union acpi_object *amdgpu_atcs_call(acpi_handle handle, int function,
+                                          struct acpi_buffer *params)
+{
+       acpi_status status;
+       union acpi_object atcs_arg_elements[2];
+       struct acpi_object_list atcs_arg;
+       struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+
+       atcs_arg.count = 2;
+       atcs_arg.pointer = &atcs_arg_elements[0];
+
+       atcs_arg_elements[0].type = ACPI_TYPE_INTEGER;
+       atcs_arg_elements[0].integer.value = function;
+
+       if (params) {
+               atcs_arg_elements[1].type = ACPI_TYPE_BUFFER;
+               atcs_arg_elements[1].buffer.length = params->length;
+               atcs_arg_elements[1].buffer.pointer = params->pointer;
+       } else {
+               /* We need a second fake parameter */
+               atcs_arg_elements[1].type = ACPI_TYPE_INTEGER;
+               atcs_arg_elements[1].integer.value = 0;
+       }
+
+       status = acpi_evaluate_object(handle, "ATCS", &atcs_arg, &buffer);
+
+       /* Fail only if calling the method fails and ATIF is supported */
+       if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
+               DRM_DEBUG_DRIVER("failed to evaluate ATCS got %s\n",
+                                acpi_format_exception(status));
+               kfree(buffer.pointer);
+               return NULL;
+       }
+
+       return buffer.pointer;
+}
+
+/**
+ * amdgpu_atcs_parse_functions - parse supported functions
+ *
+ * @f: supported functions struct
+ * @mask: supported functions mask from ATCS
+ *
+ * Use the supported functions mask from ATCS function
+ * ATCS_FUNCTION_VERIFY_INTERFACE to determine what functions
+ * are supported (all asics).
+ */
+static void amdgpu_atcs_parse_functions(struct amdgpu_atcs_functions *f, u32 mask)
+{
+       f->get_ext_state = mask & ATCS_GET_EXTERNAL_STATE_SUPPORTED;
+       f->pcie_perf_req = mask & ATCS_PCIE_PERFORMANCE_REQUEST_SUPPORTED;
+       f->pcie_dev_rdy = mask & ATCS_PCIE_DEVICE_READY_NOTIFICATION_SUPPORTED;
+       f->pcie_bus_width = mask & ATCS_SET_PCIE_BUS_WIDTH_SUPPORTED;
+}
+
+/**
+ * amdgpu_atcs_verify_interface - verify ATCS
+ *
+ * @handle: acpi handle
+ * @atcs: amdgpu atcs struct
+ *
+ * Execute the ATCS_FUNCTION_VERIFY_INTERFACE ATCS function
+ * to initialize ATCS and determine what features are supported
+ * (all asics).
+ * returns 0 on success, error on failure.
+ */
+static int amdgpu_atcs_verify_interface(acpi_handle handle,
+                                       struct amdgpu_atcs *atcs)
+{
+       union acpi_object *info;
+       struct atcs_verify_interface output;
+       size_t size;
+       int err = 0;
+
+       info = amdgpu_atcs_call(handle, ATCS_FUNCTION_VERIFY_INTERFACE, NULL);
+       if (!info)
+               return -EIO;
+
+       memset(&output, 0, sizeof(output));
+
+       size = *(u16 *) info->buffer.pointer;
+       if (size < 8) {
+               DRM_INFO("ATCS buffer is too small: %zu\n", size);
+               err = -EINVAL;
+               goto out;
+       }
+       size = min(sizeof(output), size);
+
+       memcpy(&output, info->buffer.pointer, size);
+
+       /* TODO: check version? */
+       DRM_DEBUG_DRIVER("ATCS version %u\n", output.version);
+
+       amdgpu_atcs_parse_functions(&atcs->functions, output.function_bits);
+
+out:
+       kfree(info);
+       return err;
+}
+
+/**
+ * amdgpu_acpi_is_pcie_performance_request_supported
+ *
+ * @adev: amdgpu_device pointer
+ *
+ * Check if the ATCS pcie_perf_req and pcie_dev_rdy methods
+ * are supported (all asics).
+ * returns true if supported, false if not.
+ */
+bool amdgpu_acpi_is_pcie_performance_request_supported(struct amdgpu_device *adev)
+{
+       struct amdgpu_atcs *atcs = &adev->atcs;
+
+       if (atcs->functions.pcie_perf_req && atcs->functions.pcie_dev_rdy)
+               return true;
+
+       return false;
+}
+
+/**
+ * amdgpu_acpi_pcie_notify_device_ready
+ *
+ * @adev: amdgpu_device pointer
+ *
+ * Executes the PCIE_DEVICE_READY_NOTIFICATION method
+ * (all asics).
+ * returns 0 on success, error on failure.
+ */
+int amdgpu_acpi_pcie_notify_device_ready(struct amdgpu_device *adev)
+{
+       acpi_handle handle;
+       union acpi_object *info;
+       struct amdgpu_atcs *atcs = &adev->atcs;
+
+       /* Get the device handle */
+       handle = ACPI_HANDLE(&adev->pdev->dev);
+       if (!handle)
+               return -EINVAL;
+
+       if (!atcs->functions.pcie_dev_rdy)
+               return -EINVAL;
+
+       info = amdgpu_atcs_call(handle, ATCS_FUNCTION_PCIE_DEVICE_READY_NOTIFICATION, NULL);
+       if (!info)
+               return -EIO;
+
+       kfree(info);
+
+       return 0;
+}
+
+/**
+ * amdgpu_acpi_pcie_performance_request
+ *
+ * @adev: amdgpu_device pointer
+ * @perf_req: requested perf level (pcie gen speed)
+ * @advertise: set advertise caps flag if set
+ *
+ * Executes the PCIE_PERFORMANCE_REQUEST method to
+ * change the pcie gen speed (all asics).
+ * returns 0 on success, error on failure.
+ */
+int amdgpu_acpi_pcie_performance_request(struct amdgpu_device *adev,
+                                        u8 perf_req, bool advertise)
+{
+       acpi_handle handle;
+       union acpi_object *info;
+       struct amdgpu_atcs *atcs = &adev->atcs;
+       struct atcs_pref_req_input atcs_input;
+       struct atcs_pref_req_output atcs_output;
+       struct acpi_buffer params;
+       size_t size;
+       u32 retry = 3;
+
+       /* Get the device handle */
+       handle = ACPI_HANDLE(&adev->pdev->dev);
+       if (!handle)
+               return -EINVAL;
+
+       if (!atcs->functions.pcie_perf_req)
+               return -EINVAL;
+
+       atcs_input.size = sizeof(struct atcs_pref_req_input);
+       /* client id (bit 2-0: func num, 7-3: dev num, 15-8: bus num) */
+       atcs_input.client_id = adev->pdev->devfn | (adev->pdev->bus->number << 8);
+       atcs_input.valid_flags_mask = ATCS_VALID_FLAGS_MASK;
+       atcs_input.flags = ATCS_WAIT_FOR_COMPLETION;
+       if (advertise)
+               atcs_input.flags |= ATCS_ADVERTISE_CAPS;
+       atcs_input.req_type = ATCS_PCIE_LINK_SPEED;
+       atcs_input.perf_req = perf_req;
+
+       params.length = sizeof(struct atcs_pref_req_input);
+       params.pointer = &atcs_input;
+
+       while (retry--) {
+               info = amdgpu_atcs_call(handle, ATCS_FUNCTION_PCIE_PERFORMANCE_REQUEST, &params);
+               if (!info)
+                       return -EIO;
+
+               memset(&atcs_output, 0, sizeof(atcs_output));
+
+               size = *(u16 *) info->buffer.pointer;
+               if (size < 3) {
+                       DRM_INFO("ATCS buffer is too small: %zu\n", size);
+                       kfree(info);
+                       return -EINVAL;
+               }
+               size = min(sizeof(atcs_output), size);
+
+               memcpy(&atcs_output, info->buffer.pointer, size);
+
+               kfree(info);
+
+               switch (atcs_output.ret_val) {
+               case ATCS_REQUEST_REFUSED:
+               default:
+                       return -EINVAL;
+               case ATCS_REQUEST_COMPLETE:
+                       return 0;
+               case ATCS_REQUEST_IN_PROGRESS:
+                       udelay(10);
+                       break;
+               }
+       }
+
+       return 0;
+}
+
+/**
+ * amdgpu_acpi_event - handle notify events
+ *
+ * @nb: notifier block
+ * @val: val
+ * @data: acpi event
+ *
+ * Calls relevant amdgpu functions in response to various
+ * acpi events.
+ * Returns NOTIFY code
+ */
+static int amdgpu_acpi_event(struct notifier_block *nb,
+                            unsigned long val,
+                            void *data)
+{
+       struct amdgpu_device *adev = container_of(nb, struct amdgpu_device, acpi_nb);
+       struct acpi_bus_event *entry = (struct acpi_bus_event *)data;
+
+       if (strcmp(entry->device_class, ACPI_AC_CLASS) == 0) {
+               if (power_supply_is_system_supplied() > 0)
+                       DRM_DEBUG_DRIVER("pm: AC\n");
+               else
+                       DRM_DEBUG_DRIVER("pm: DC\n");
+
+               amdgpu_pm_acpi_event_handler(adev);
+       }
+
+       /* Check for pending SBIOS requests */
+       return amdgpu_atif_handler(adev, entry);
+}
+
+/* Call all ACPI methods here */
+/**
+ * amdgpu_acpi_init - init driver acpi support
+ *
+ * @adev: amdgpu_device pointer
+ *
+ * Verifies the AMD ACPI interfaces and registers with the acpi
+ * notifier chain (all asics).
+ * Returns 0 on success, error on failure.
+ */
+int amdgpu_acpi_init(struct amdgpu_device *adev)
+{
+       acpi_handle handle;
+       struct amdgpu_atif *atif = &adev->atif;
+       struct amdgpu_atcs *atcs = &adev->atcs;
+       int ret;
+
+       /* Get the device handle */
+       handle = ACPI_HANDLE(&adev->pdev->dev);
+
+       if (!adev->bios || !handle)
+               return 0;
+
+       /* Call the ATCS method */
+       ret = amdgpu_atcs_verify_interface(handle, atcs);
+       if (ret) {
+               DRM_DEBUG_DRIVER("Call to ATCS verify_interface failed: %d\n", ret);
+       }
+
+       /* Call the ATIF method */
+       ret = amdgpu_atif_verify_interface(handle, atif);
+       if (ret) {
+               DRM_DEBUG_DRIVER("Call to ATIF verify_interface failed: %d\n", ret);
+               goto out;
+       }
+
+       if (atif->notifications.brightness_change) {
+               struct drm_encoder *tmp;
+
+               /* Find the encoder controlling the brightness */
+               list_for_each_entry(tmp, &adev->ddev->mode_config.encoder_list,
+                               head) {
+                       struct amdgpu_encoder *enc = to_amdgpu_encoder(tmp);
+
+                       if ((enc->devices & (ATOM_DEVICE_LCD_SUPPORT)) &&
+                           enc->enc_priv) {
+                               if (adev->is_atom_bios) {
+                                       struct amdgpu_encoder_atom_dig *dig = enc->enc_priv;
+                                       if (dig->bl_dev) {
+                                               atif->encoder_for_bl = enc;
+                                               break;
+                                       }
+                               }
+                       }
+               }
+       }
+
+       if (atif->functions.sbios_requests && !atif->functions.system_params) {
+               /* XXX check this workraround, if sbios request function is
+                * present we have to see how it's configured in the system
+                * params
+                */
+               atif->functions.system_params = true;
+       }
+
+       if (atif->functions.system_params) {
+               ret = amdgpu_atif_get_notification_params(handle,
+                               &atif->notification_cfg);
+               if (ret) {
+                       DRM_DEBUG_DRIVER("Call to GET_SYSTEM_PARAMS failed: %d\n",
+                                       ret);
+                       /* Disable notification */
+                       atif->notification_cfg.enabled = false;
+               }
+       }
+
+out:
+       adev->acpi_nb.notifier_call = amdgpu_acpi_event;
+       register_acpi_notifier(&adev->acpi_nb);
+
+       return ret;
+}
+
+/**
+ * amdgpu_acpi_fini - tear down driver acpi support
+ *
+ * @adev: amdgpu_device pointer
+ *
+ * Unregisters with the acpi notifier chain (all asics).
+ */
+void amdgpu_acpi_fini(struct amdgpu_device *adev)
+{
+       unregister_acpi_notifier(&adev->acpi_nb);
+}