drm/radeon: implement handler for ACPI event

Set up an handler for ACPI events and respond to brightness change
requests from the system BIOS.
v2: fix notification when using device-specific command codes
(tested by Pali Rohár <pali.rohar@gmail.com>); cache the encoder
controlling the backlight during the initialization to avoid searching
it every time (suggested by Alex Deucher).
v3: whitespace fixes (Alex Deucher).

Signed-off-by: Luca Tettamanti <kronos.it@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

7 files changed, 152 insertions, 11 deletions

diff --git a/drivers/gpu/drm/radeon/atombios_encoders.c b/drivers/gpu/drm/radeon/atombios_encoders.c
index f3645e15ef11..370b2c4a7c86 100644
--- a/drivers/gpu/drm/radeon/atombios_encoders.c
+++ b/drivers/gpu/drm/radeon/atombios_encoders.c
@@ -72,7 +72,7 @@ radeon_atom_set_backlight_level_to_reg(struct radeon_device *rdev,
                 WREG32(RADEON_BIOS_2_SCRATCH, bios_2_scratch);
 }
 
-static void
+void
 atombios_set_panel_brightness(struct radeon_encoder *radeon_encoder)
 {
         struct drm_encoder *encoder = &radeon_encoder->base;
diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
index 763f3333776e..dea5f08bd23b 100644
--- a/drivers/gpu/drm/radeon/radeon.h
+++ b/drivers/gpu/drm/radeon/radeon.h
@@ -1461,6 +1461,7 @@ struct radeon_atif {
         struct radeon_atif_notifications notifications;
         struct radeon_atif_functions functions;
         struct radeon_atif_notification_cfg notification_cfg;
+        struct radeon_encoder *backlight_ctl;
 };
 
 /*
diff --git a/drivers/gpu/drm/radeon/radeon_acpi.c b/drivers/gpu/drm/radeon/radeon_acpi.c
index 0454eccc9c03..b052a556db79 100644
--- a/drivers/gpu/drm/radeon/radeon_acpi.c
+++ b/drivers/gpu/drm/radeon/radeon_acpi.c
@@ -26,6 +26,7 @@
 #include <linux/slab.h>
 #include <acpi/acpi_drivers.h>
 #include <acpi/acpi_bus.h>
+#include <acpi/video.h>
 
 #include "drmP.h"
 #include "drm.h"
@@ -33,6 +34,7 @@
 #include "drm_crtc_helper.h"
 #include "radeon.h"
 #include "radeon_acpi.h"
+#include "atom.h"
 
 #include <linux/vga_switcheroo.h>
 
@@ -44,10 +46,22 @@ struct atif_verify_interface {
 } __packed;
 
 struct atif_system_params {
-        u16 size;
-        u32 valid_mask;
-        u32 flags;
-        u8 command_code;
+        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
@@ -180,6 +194,8 @@ static int radeon_atif_get_notification_params(acpi_handle handle,
         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) {
@@ -198,10 +214,91 @@ static int radeon_atif_get_notification_params(acpi_handle handle,
         }
 
 out:
+        DRM_DEBUG_DRIVER("Notification %s, command code = %#x\n",
+                        (n->enabled ? "enabled" : "disabled"),
+                        n->command_code);
         kfree(info);
         return err;
 }
 
+static int radeon_atif_get_sbios_requests(acpi_handle handle,
+                struct atif_sbios_requests *req)
+{
+        union acpi_object *info;
+        size_t size;
+        int count = 0;
+
+        info = radeon_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;
+}
+
+int radeon_atif_handler(struct radeon_device *rdev,
+                struct acpi_bus_event *event)
+{
+        struct radeon_atif *atif = &rdev->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 = DEVICE_ACPI_HANDLE(&rdev->pdev->dev);
+        count = radeon_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 radeon_encoder *enc = atif->backlight_ctl;
+
+                if (enc) {
+                        struct radeon_encoder_atom_dig *dig = enc->enc_priv;
+                        dig->backlight_level = req.backlight_level;
+
+                        DRM_DEBUG_DRIVER("Changing brightness to %d\n",
+                                        req.backlight_level);
+
+                        atombios_set_panel_brightness(enc);
+
+                        backlight_force_update(dig->bl_dev,
+                                        BACKLIGHT_UPDATE_HOTKEY);
+                }
+        }
+        /* TODO: check other events */
+
+        return NOTIFY_OK;
+}
+
 /* Call all ACPI methods here */
 int radeon_acpi_init(struct radeon_device *rdev)
 {
@@ -223,6 +320,33 @@ int radeon_acpi_init(struct radeon_device *rdev)
                 goto out;
         }
 
+        if (atif->notifications.brightness_change) {
+                struct drm_encoder *tmp;
+                struct radeon_encoder *target = NULL;
+
+                /* Find the encoder controlling the brightness */
+                list_for_each_entry(tmp, &rdev->ddev->mode_config.encoder_list,
+                                head) {
+                        struct radeon_encoder *enc = to_radeon_encoder(tmp);
+                        struct radeon_encoder_atom_dig *dig = enc->enc_priv;
+
+                        if ((enc->devices & (ATOM_DEVICE_LCD_SUPPORT)) &&
+                                        dig->bl_dev != NULL) {
+                                target = enc;
+                                break;
+                        }
+                }
+
+                atif->backlight_ctl = target;
+                if (!target) {
+                        /* Brightness change notification is enabled, but we
+                         * didn't find a backlight controller, this should
+                         * never happen.
+                         */
+                        DRM_ERROR("Cannot find a backlight controller\n");
+                }
+        }
+
         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
diff --git a/drivers/gpu/drm/radeon/radeon_acpi.h b/drivers/gpu/drm/radeon/radeon_acpi.h
index 642aa4719454..be4af76f213d 100644
--- a/drivers/gpu/drm/radeon/radeon_acpi.h
+++ b/drivers/gpu/drm/radeon/radeon_acpi.h
@@ -24,6 +24,12 @@
 #ifndef RADEON_ACPI_H
 #define RADEON_ACPI_H
 
+struct radeon_device;
+struct acpi_bus_event;
+
+int radeon_atif_handler(struct radeon_device *rdev,
+                struct acpi_bus_event *event);
+
 /* AMD hw uses four ACPI control methods:
  * 1. ATIF
  * ARG0: (ACPI_INTEGER) function code
diff --git a/drivers/gpu/drm/radeon/radeon_kms.c b/drivers/gpu/drm/radeon/radeon_kms.c
index 414b4acf6947..8c2471854cd7 100644
--- a/drivers/gpu/drm/radeon/radeon_kms.c
+++ b/drivers/gpu/drm/radeon/radeon_kms.c
@@ -103,11 +103,6 @@ int radeon_driver_load_kms(struct drm_device *dev, unsigned long flags)
                 goto out;
         }
 
-        /* Call ACPI methods */
-        acpi_status = radeon_acpi_init(rdev);
-        if (acpi_status)
-                dev_dbg(&dev->pdev->dev, "Error during ACPI methods call\n");
-
         /* Again modeset_init should fail only on fatal error
          * otherwise it should provide enough functionalities
          * for shadowfb to run
@@ -115,6 +110,17 @@ int radeon_driver_load_kms(struct drm_device *dev, unsigned long flags)
         r = radeon_modeset_init(rdev);
         if (r)
                 dev_err(&dev->pdev->dev, "Fatal error during modeset init\n");
+
+        /* Call ACPI methods: require modeset init
+         * but failure is not fatal
+         */
+        if (!r) {
+                acpi_status = radeon_acpi_init(rdev);
+                if (acpi_status)
+                dev_dbg(&dev->pdev->dev,
+                                "Error during ACPI methods call\n");
+        }
+
 out:
         if (r)
                 radeon_driver_unload_kms(dev);
diff --git a/drivers/gpu/drm/radeon/radeon_mode.h b/drivers/gpu/drm/radeon/radeon_mode.h
index 5005057974b1..1f411c2609d8 100644
--- a/drivers/gpu/drm/radeon/radeon_mode.h
+++ b/drivers/gpu/drm/radeon/radeon_mode.h
@@ -698,6 +698,8 @@ void radeon_panel_mode_fixup(struct drm_encoder *encoder,
                              struct drm_display_mode *adjusted_mode);
 void atom_rv515_force_tv_scaler(struct radeon_device *rdev, struct radeon_crtc *radeon_crtc);
 
+void atombios_set_panel_brightness(struct radeon_encoder *radeon_encoder);
+
 /* legacy tv */
 void radeon_legacy_tv_adjust_crtc_reg(struct drm_encoder *encoder,
                                       uint32_t *h_total_disp, uint32_t *h_sync_strt_wid,
diff --git a/drivers/gpu/drm/radeon/radeon_pm.c b/drivers/gpu/drm/radeon/radeon_pm.c
index 2c2c901226f4..14e544e0eb31 100644
--- a/drivers/gpu/drm/radeon/radeon_pm.c
+++ b/drivers/gpu/drm/radeon/radeon_pm.c
@@ -22,6 +22,7 @@
  */
 #include "drmP.h"
 #include "radeon.h"
+#include "radeon_acpi.h"
 #include "avivod.h"
 #include "atom.h"
 #ifdef CONFIG_ACPI
@@ -94,7 +95,8 @@ static int radeon_acpi_event(struct notifier_block *nb,
                 }
         }
 
-        return NOTIFY_OK;
+        /* Check for pending SBIOS requests */
+        return radeon_atif_handler(rdev, entry);
 }
 #endif