soc/intel/mtl: Hook up GMA ACPI brightness controls

Add function needed to generate ACPI backlight control SSDT, along with
Kconfig values for accessing the registers.

Change-Id: Ied08e5e9fe4913bd60474ed7dcf88b945172558d
Signed-off-by: Jeremy Soller <jeremy@sysetm76.com>
Signed-off-by: Tim Crawford <tcrawford@system76.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/82729
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>

src/soc/intel/meteorlake/Kconfig

@@ -380,6 +380,18 @@ config SOC_INTEL_GFX_FRAMEBUFFER_OFFSET
 	hex
 	default 0x800000
 
+config INTEL_GMA_BCLV_OFFSET
+	default 0xc8258
+
+config INTEL_GMA_BCLV_WIDTH
+	default 32
+
+config INTEL_GMA_BCLM_OFFSET
+	default 0xc8254
+
+config INTEL_GMA_BCLM_WIDTH
+	default 32
+
 config DROP_CPU_FEATURE_PROGRAM_IN_FSP
 	bool
 	default y if MP_SERVICES_PPI_V2_NOOP || CHROMEOS

src/soc/intel/meteorlake/Makefile.mk

@@ -36,6 +36,7 @@ ramstage-y += elog.c
 ramstage-y += espi.c
 ramstage-y += finalize.c
 ramstage-y += fsp_params.c
+ramstage-y += graphics.c
 ramstage-y += lockdown.c
 ramstage-y += p2sb.c
 ramstage-y += pcie_rp.c

src/soc/intel/meteorlake/chip.h

@@ -4,6 +4,7 @@
 #define _SOC_CHIP_H_
 
 #include <drivers/i2c/designware/dw_i2c.h>
+#include <drivers/intel/gma/gma.h>
 #include <device/pci_ids.h>
 #include <gpio.h>
 #include <intelblocks/cfg.h>
@@ -528,6 +529,9 @@ struct soc_intel_meteorlake_config {
 	 * as per `enum slew_rate` data type.
 	 */
 	uint8_t slow_slew_rate_config[NUM_VR_DOMAINS];
+
+	/* i915 struct for GMA backlight control */
+	struct i915_gpu_controller_info gfx;
 };
 
 typedef struct soc_intel_meteorlake_config config_t;

src/soc/intel/meteorlake/graphics.c

@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#include <intelblocks/graphics.h>
+#include <soc/ramstage.h>
+
+const struct i915_gpu_controller_info *
+intel_igd_get_controller_info(const struct device *const dev)
+{
+	const struct soc_intel_meteorlake_config *const chip = dev->chip_info;
+	return &chip->gfx;
+}