This is a modified version of Hong's patch from last month, with a few

modifications to make it work correctly on my test hardware (altered the
backlight write function, made it enable the legacy backlight controller
interrupts on mobile hardware, sorted the interrupt function so we don't
get an excessive number of vblank interrupts). This lets the backlight
keys on my T61 work properly, though there's a 750msec or so delay
between the request and the brightness actually changing - this sounds
awfully like the hardware spinning waiting for a status flag to become
ready, but as far as I can tell they're all set correctly. If anyone can
figure out what's wrong here, it'd be nice to know.

Some of the functions are still stubs and just tell the hardware that
the request was successful. These can be filled in as kernel modesetting
gets integrated. I think it's worth getting this in anyway, since it's
required for backlight control to work properly on some new platforms.

Signed-off-by: Matthew Garrett <mjg@redhat.com>

3 files changed, 57 insertions, 0 deletions

diff --git a/shared-core/i915_dma.c b/shared-core/i915_dma.c
index 27d152cb..ad6e1293 100644
--- a/shared-core/i915_dma.c
+++ b/shared-core/i915_dma.c
@@ -1038,6 +1038,7 @@ int i915_driver_load(struct drm_device *dev, unsigned long flags)
 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,25)
 	intel_init_chipset_flush_compat(dev);
 #endif
+	intel_opregion_init(dev);
 #endif
 
 	return ret;
@@ -1050,6 +1051,10 @@ int i915_driver_unload(struct drm_device *dev)
 	if (dev_priv->mmio_map)
 		drm_rmmap(dev, dev_priv->mmio_map);
 
+#ifdef __linux__
+	intel_opregion_free(dev);
+#endif
+
 	drm_free(dev->dev_private, sizeof(drm_i915_private_t),
 		 DRM_MEM_DRIVER);
 #ifdef __linux__
diff --git a/shared-core/i915_drv.h b/shared-core/i915_drv.h
index fa3305ba..421572cd 100644
--- a/shared-core/i915_drv.h
+++ b/shared-core/i915_drv.h
@@ -105,6 +105,22 @@ typedef struct _drm_i915_vbl_swap {
 	int flip;
 } drm_i915_vbl_swap_t;
 
+#ifdef __linux__
+struct opregion_header;
+struct opregion_acpi;
+struct opregion_swsci;
+struct opregion_asle;
+
+struct intel_opregion {
+	struct opregion_header *header;
+	struct opregion_acpi *acpi;
+	struct opregion_swsci *swsci;
+	struct opregion_asle *asle;
+
+	int enabled;
+};
+#endif
+
 typedef struct drm_i915_private {
 	drm_local_map_t *sarea;
 	drm_local_map_t *mmio_map;
@@ -158,6 +174,11 @@ typedef struct drm_i915_private {
 	struct drm_buffer_object *sarea_bo;
 	struct drm_bo_kmap_obj sarea_kmap;
 #endif
+
+#ifdef __linux__
+	struct intel_opregion opregion;
+#endif
+
 	/* Register state */
 	u8 saveLBB;
 	u32 saveDSPACNTR;
@@ -343,6 +364,14 @@ int i915_execbuffer(struct drm_device *dev, void *data,
 #endif
 
 #ifdef __linux__
+/* i915_opregion.c */
+extern int intel_opregion_init(struct drm_device *dev);
+extern void intel_opregion_free(struct drm_device *dev);
+extern void opregion_asle_intr(struct drm_device *dev);
+extern void opregion_enable_asle(struct drm_device *dev);
+#endif
+
+#ifdef __linux__
 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,25)
 extern void intel_init_chipset_flush_compat(struct drm_device *dev);
 extern void intel_fini_chipset_flush_compat(struct drm_device *dev);
@@ -613,6 +642,7 @@ extern int i915_wait_ring(struct drm_device * dev, int n, const char *caller);
 #define   I915_DISPLAY_PIPE_B_EVENT_INTERRUPT		(1<<4)
 #define   I915_DEBUG_INTERRUPT				(1<<2)
 #define   I915_USER_INTERRUPT				(1<<1)
+#define   I915_ASLE_INTERRUPT				(1<<0)
 #define EIR		0x020b0
 #define EMR		0x020b4
 #define ESR		0x020b8
diff --git a/shared-core/i915_irq.c b/shared-core/i915_irq.c
index 28f9f6af..d7fa47d3 100644
--- a/shared-core/i915_irq.c
+++ b/shared-core/i915_irq.c
@@ -474,15 +474,33 @@ irqreturn_t i915_driver_irq_handler(DRM_IRQ_ARGS)
 	}
 	if (iir & I915_DISPLAY_PIPE_B_EVENT_INTERRUPT) {
 		pipeb_stats = I915_READ(PIPEBSTAT);
+		/* Ack the event */
+		I915_WRITE(PIPEBSTAT, pipeb_stats);
+
+		/* The vblank interrupt gets enabled even if we didn't ask for
+		   it, so make sure it's shut down again */
+		if (!(dev_priv->vblank_pipe & DRM_I915_VBLANK_PIPE_B))
+			pipeb_stats &= ~(I915_VBLANK_INTERRUPT_ENABLE);
+
 		if (pipeb_stats & (PIPE_START_VBLANK_INTERRUPT_STATUS|
 				   PIPE_VBLANK_INTERRUPT_STATUS))
 		{
 			vblank++;
 			drm_handle_vblank(dev, i915_get_plane(dev, 1));
 		}
+
+#ifdef __linux__
+		if (pipeb_stats & I915_LEGACY_BLC_EVENT_ENABLE)
+			opregion_asle_intr(dev);
+#endif
 		I915_WRITE(PIPEBSTAT, pipeb_stats);
 	}
 
+#ifdef __linux__
+	if (iir & I915_ASLE_INTERRUPT)
+		opregion_asle_intr(dev);
+#endif
+
 	if (dev_priv->sarea_priv)
 	    dev_priv->sarea_priv->last_dispatch = READ_BREADCRUMB(dev_priv);
 
@@ -703,6 +721,10 @@ static void i915_enable_interrupt (struct drm_device *dev)
 	
 	dev_priv->irq_enable_reg |= I915_USER_INTERRUPT;
 
+#ifdef __linux__
+	opregion_enable_asle(dev);
+#endif
+
 	I915_WRITE(IER, dev_priv->irq_enable_reg);
 	dev_priv->irq_enabled = 1;
 }