intel_extreme: set/get brightness in legacy mode for gen2,i915GM,i945GM

untested, see #15448

Change-Id: Iaf0cdacd39ebadfc143b072bdd6f5435a1394f45
Reviewed-on: https://review.haiku-os.org/c/haiku/+/5222
Tested-by: Commit checker robot <[email protected]>
Reviewed-by: Adrien Destugues <[email protected]>

headers/private/graphics/intel_extreme/intel_extreme.h

@@ -398,7 +398,9 @@ enum {
 
 	INTEL_GET_DEVICE_NAME,
 	INTEL_ALLOCATE_GRAPHICS_MEMORY,
-	INTEL_FREE_GRAPHICS_MEMORY
+	INTEL_FREE_GRAPHICS_MEMORY,
+	INTEL_GET_BRIGHTNESS_LEGACY,
+	INTEL_SET_BRIGHTNESS_LEGACY
 };
 
 // retrieve the area_id of the kernel/accelerant shared info
@@ -422,6 +424,12 @@ struct intel_free_graphics_memory {
 	addr_t	buffer_base;
 };
 
+// brightness legacy
+struct intel_brightness_legacy {
+	uint32 	magic;
+	uint8	lpc;
+};
+
 //----------------------------------------------------------
 // Register definitions, taken from X driver
 
@@ -535,6 +543,9 @@ struct intel_free_graphics_memory {
 #define BDW_GTT_SIZE_4MB				(2 << 6)
 #define BDW_GTT_SIZE_8MB				(3 << 6)
 
+// Gen2, i915GM, i945GM
+#define LEGACY_BACKLIGHT_BRIGHTNESS		0xf4
+
 // graphics page translation table
 #define INTEL_PAGE_TABLE_CONTROL		0x02020
 #define PAGE_TABLE_ENABLED				0x00000001
@@ -1218,6 +1229,7 @@ struct intel_free_graphics_memory {
 #define MCH_BLC_PWM_CTL                 (0x1254 | REGS_NORTH_PIPE_AND_PORT)
 	// Linux VLV_BLC_PWM_CTL (one register per pipe) or BLC_PWM_CTL (a single register that can be
 	// programmed for use on either pipe)
+#define BLM_LEGACY_MODE					(1 << 16)
 
 // ring buffer commands
 

src/add-ons/accelerants/intel_extreme/mode.cpp

@@ -633,6 +633,13 @@ intel_set_brightness(float brightness)
 	} else {
 		// On older devices there is a single register with both period and duty cycle
 		uint32 tmp = read32(intel_get_backlight_register(true));
+		bool legacyMode = false;
+		if (gInfo->shared_info->device_type.Generation() == 2
+			|| gInfo->shared_info->device_type.IsModel(INTEL_MODEL_915M)
+			|| gInfo->shared_info->device_type.IsModel(INTEL_MODEL_945M)) {
+			legacyMode = (tmp & BLM_LEGACY_MODE) != 0;
+		}
+
 		uint32_t period = tmp >> 16;
 
 		uint32_t mask = 0xffff;
@@ -645,7 +652,21 @@ intel_set_brightness(float brightness)
 			shift = 1;
 			period = tmp >> 17;
 		}
+		if (legacyMode)
+			period *= 0xfe;
 		uint32_t duty = (uint32_t)(period * brightness);
+		if (legacyMode) {
+			uint8 lpc = duty / 0xff + 1;
+			duty /= lpc;
+
+			// set pci config reg with lpc
+			intel_brightness_legacy brightnessLegacy;
+			brightnessLegacy.magic = INTEL_PRIVATE_DATA_MAGIC;
+			brightnessLegacy.lpc = lpc;
+			ioctl(gInfo->device, INTEL_SET_BRIGHTNESS_LEGACY, &brightnessLegacy,
+				sizeof(brightnessLegacy));
+		}
+
 		duty = std::max(duty, (uint32_t)gInfo->shared_info->min_brightness);
 		duty <<= shift;
 
@@ -671,9 +692,25 @@ intel_get_brightness(float* brightness)
 		period = read32(intel_get_backlight_register(true));
 		duty = read32(intel_get_backlight_register(false));
 	} else {
-		period = read32(intel_get_backlight_register(true)) >> 16;
+		uint32 tmp = read32(intel_get_backlight_register(true));
+		bool legacyMode = false;
+		if (gInfo->shared_info->device_type.Generation() == 2
+			|| gInfo->shared_info->device_type.IsModel(INTEL_MODEL_915M)
+			|| gInfo->shared_info->device_type.IsModel(INTEL_MODEL_945M)) {
+			legacyMode = (tmp & BLM_LEGACY_MODE) != 0;
+		}
+		period = tmp >> 16;
 		duty = read32(intel_get_backlight_register(false)) & 0xffff;
+		if (legacyMode) {
+			period *= 0xff;
 
+			// get lpc from pci config reg
+			intel_brightness_legacy brightnessLegacy;
+			brightnessLegacy.magic = INTEL_PRIVATE_DATA_MAGIC;
+			ioctl(gInfo->device, INTEL_GET_BRIGHTNESS_LEGACY, &brightnessLegacy,
+				sizeof(brightnessLegacy));
+			duty *= brightnessLegacy.lpc;
+		}
 		if (gInfo->shared_info->device_type.Generation() < 4) {
 			period >>= 1;
 			duty >>= 1;

src/add-ons/kernel/drivers/graphics/intel_extreme/device.cpp

@@ -337,6 +337,27 @@ device_ioctl(void* data, uint32 op, void* buffer, size_t bufferLength)
 			break;
 		}
 
+		case INTEL_GET_BRIGHTNESS_LEGACY:
+		case INTEL_SET_BRIGHTNESS_LEGACY:
+		{
+			intel_brightness_legacy brightnessLegacy;
+			if (user_memcpy(&brightnessLegacy, buffer,
+					sizeof(brightnessLegacy)) < B_OK)
+				return B_BAD_ADDRESS;
+
+			if (brightnessLegacy.magic != INTEL_PRIVATE_DATA_MAGIC)
+				break;
+			if (op == INTEL_GET_BRIGHTNESS_LEGACY) {
+				brightnessLegacy.lpc = get_pci_config(info->pci, LEGACY_BACKLIGHT_BRIGHTNESS, 1);
+				// copy result
+				if (user_memcpy(buffer, &brightnessLegacy, sizeof(brightnessLegacy)) < B_OK)
+					return B_BAD_ADDRESS;
+			} else {
+				set_pci_config(info->pci, LEGACY_BACKLIGHT_BRIGHTNESS, 1, brightnessLegacy.lpc);
+			}
+			return B_OK;
+		}
+
 		default:
 			ERROR("ioctl() unknown message %" B_PRIu32 " (length = %"
 				B_PRIuSIZE ")\n", op, bufferLength);