3 files changed, 99 insertions, 0 deletions

diff --git a/src/soc/intel/apollolake/Makefile.inc b/src/soc/intel/apollolake/Makefile.inc
index 517c8ca97d..a20a554be1 100644
--- a/src/soc/intel/apollolake/Makefile.inc
+++ b/src/soc/intel/apollolake/Makefile.inc
@@ -54,6 +54,7 @@ ramstage-y += cpu.c
 ramstage-y += chip.c
 ramstage-y += cse.c
 ramstage-y += elog.c
+ramstage-y += graphics.c
 ramstage-y += gspi.c
 ramstage-y += heci.c
 ramstage-y += i2c.c
diff --git a/src/soc/intel/apollolake/chip.h b/src/soc/intel/apollolake/chip.h
index ce446a063a..521d3ee06c 100644
--- a/src/soc/intel/apollolake/chip.h
+++ b/src/soc/intel/apollolake/chip.h
@@ -24,6 +24,22 @@ enum pnp_settings {
 	PNP_PERF_POWER,
 };
 
+struct soc_intel_apl_pp {
+	unsigned int up_delay_ms;
+	unsigned int down_delay_ms;
+	unsigned int cycle_delay_ms;
+	unsigned int backlight_on_delay_ms;
+	unsigned int backlight_off_delay_ms;
+};
+
+struct soc_intel_apl_blc {
+	unsigned int pwm_hz;
+	enum {
+		GPU_BACKLIGHT_POLARITY_HIGH = 0,
+		GPU_BACKLIGHT_POLARITY_LOW,
+	} polarity;
+};
+
 struct soc_intel_apollolake_config {
 
 	/* Common structure containing soc config data required by common code*/
@@ -32,6 +48,13 @@ struct soc_intel_apollolake_config {
 	/* Common struct containing power limits configuration info */
 	struct soc_power_limits_config power_limits_config;
 
+	/* IGD panel configuration */
+	struct soc_intel_apl_pp gpu_pp[2];
+	/* Second backlight control shares logic with other pins (aka. display
+	   utility pin). Be sure it's used for PWM before setting any value for
+	   the secondary controls. */
+	struct soc_intel_apl_blc gpu_blc[2];
+
 	/*
 	 * Mapping from PCIe root port to CLKREQ input on the SOC. The SOC has
 	 * four CLKREQ inputs, but six root ports. Root ports without an
diff --git a/src/soc/intel/apollolake/graphics.c b/src/soc/intel/apollolake/graphics.c
new file mode 100644
index 0000000000..24d47721ab
--- /dev/null
+++ b/src/soc/intel/apollolake/graphics.c
@@ -0,0 +1,75 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#include <stdint.h>
+#include <commonlib/helpers.h>
+#include <device/device.h>
+#include <device/mmio.h>
+#include <device/pci_def.h>
+#include <intelblocks/graphics.h>
+#include <drivers/intel/gma/i915_reg.h>
+
+#include "chip.h"
+
+static void graphics_configure_panelpower(
+		const struct soc_intel_apl_pp *const pp,
+		uint8_t *const mmio, const unsigned int panel_idx)
+{
+	const unsigned int offset = panel_idx * 0x100;
+	uint32_t reg32;
+
+	reg32 = ((DIV_ROUND_UP(pp->cycle_delay_ms, 100) + 1) & 0x1f) | PANEL_POWER_RESET;
+	write32(mmio + PCH_PP_CONTROL + offset, reg32);
+
+	reg32 = pp->up_delay_ms * 10 << 16;
+	reg32 |= pp->backlight_on_delay_ms * 10;
+	write32(mmio + PCH_PP_ON_DELAYS + offset, reg32);
+
+	reg32 = pp->down_delay_ms * 10 << 16;
+	reg32 |= pp->backlight_off_delay_ms * 10;
+	write32(mmio + PCH_PP_OFF_DELAYS + offset, reg32);
+}
+
+static void graphics_configure_backlight(
+		const struct soc_intel_apl_blc *const blc,
+		uint8_t *const mmio, const unsigned int panel_idx)
+{
+	if (!blc->pwm_hz)
+		return;
+
+	const unsigned int pwm_period = 19200 * 1000 / blc->pwm_hz;
+	write32(mmio + BXT_BLC_PWM_FREQ(panel_idx), pwm_period);
+	write32(mmio + BXT_BLC_PWM_DUTY(panel_idx), pwm_period / 2);
+	write32(mmio + BXT_BLC_PWM_CTL(panel_idx),
+		(blc->polarity ? BXT_BLC_PWM_POLARITY : 0));
+
+	/* Second backlight control uses display utility pin. */
+	if (panel_idx == 1) {
+		write32(mmio + UTIL_PIN_CTL, 0); /* Make sure it's disabled, don't know
+						    what FSP might have done already. */
+		write32(mmio + UTIL_PIN_CTL, UTIL_PIN_MODE_PWM | UTIL_PIN_ENABLE);
+	}
+}
+
+void graphics_soc_init(struct device *const dev)
+{
+	const struct soc_intel_apollolake_config *const conf = dev->chip_info;
+	const struct resource *mmio_res;
+	void *mmio;
+	unsigned int i;
+
+	/* Some hardware configuration first. */
+
+	if (!conf)
+		return;
+
+	mmio_res = probe_resource(dev, PCI_BASE_ADDRESS_0);
+	if (!mmio_res || !mmio_res->base)
+		return;
+	mmio = (void *)(uintptr_t)mmio_res->base;
+
+	for (i = 0; i < ARRAY_SIZE(conf->gpu_pp); ++i)
+		graphics_configure_panelpower(&conf->gpu_pp[i], mmio, i);
+
+	for (i = 0; i < ARRAY_SIZE(conf->gpu_blc); ++i)
+		graphics_configure_backlight(&conf->gpu_blc[i], mmio, i);
+}