google/trogdor: Add backlight support for Parade ps8640

Add backlight support in ps8640 through the AUX channel using eDP
DPCD registers.

BUG=b:202966352
BRANCH=trogdor
TEST=verified firmware screen works on homestar rev4

Change-Id: Ief1bf56c89c8215427dcbddfc67e8bcd4c3607d2
Signed-off-by: xuxinxiong <xuxinxiong@huaqin.corp-partner.google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/58624
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>

6 files changed, 219 insertions, 77 deletions

diff --git a/src/drivers/parade/ps8640/ps8640.c b/src/drivers/parade/ps8640/ps8640.c
index 93121f209459..587eae1d9c00 100644
--- a/src/drivers/parade/ps8640/ps8640.c
+++ b/src/drivers/parade/ps8640/ps8640.c
@@ -5,7 +5,7 @@
 #include <edid.h>
 #include <console/console.h>
 #include <timer.h>
-
+#include <dp_aux.h>
 #include "ps8640.h"
 
 int ps8640_get_edid(uint8_t bus, uint8_t chip, struct edid *out)
@@ -80,3 +80,101 @@ int ps8640_init(uint8_t bus, uint8_t chip)
 
 	return 0;
 }
+
+static cb_err_t ps8640_bridge_aux_request(uint8_t bus,
+					  uint8_t chip,
+					  unsigned int target_reg,
+					  unsigned int total_size,
+					  enum aux_request request,
+					  uint8_t *data)
+{
+	int i;
+	uint32_t length;
+	uint8_t buf;
+	uint8_t reg;
+	int ret;
+
+	if (target_reg & ~SWAUX_ADDR_MASK)
+		return CB_ERR;
+
+	while (total_size) {
+		length = MIN(total_size, DP_AUX_MAX_PAYLOAD_BYTES);
+		total_size -= length;
+
+		ret = i2c_writeb(bus, chip, PAGE0_AUXCH_CFG3, AUXCH_CFG3_RESET);
+		if (ret)
+			return CB_ERR;
+
+		enum i2c_over_aux cmd = dp_get_aux_cmd(request, total_size);
+		if (i2c_writeb(bus, chip, PAGE0_SWAUX_ADDR_23_16,
+			(target_reg >> 16) | (cmd << 4)) ||
+		    i2c_writeb(bus, chip, PAGE0_SWAUX_ADDR_15_8, target_reg >> 8) ||
+		    i2c_writeb(bus, chip, PAGE0_SWAUX_ADDR_7_0, target_reg)) {
+			return CB_ERR;
+		}
+
+		if (dp_aux_request_is_write(request)) {
+			reg = PAGE0_SWAUX_WDATA;
+			for (i = 0; i < length; i++) {
+				ret = i2c_writeb(bus, chip, reg++, *data++);
+				if (ret)
+					return CB_ERR;
+			}
+		} else {
+			if (length == 0)
+				i2c_writeb(bus, chip, PAGE0_SWAUX_LENGTH, SWAUX_NO_PAYLOAD);
+			else
+				i2c_writeb(bus, chip, PAGE0_SWAUX_LENGTH, length - 1);
+		}
+
+		ret = i2c_writeb(bus, chip, PAGE0_SWAUX_CTRL, SWAUX_SEND);
+		if (ret)
+			return CB_ERR;
+
+		if (!wait_ms(100, !i2c_readb(bus, chip, PAGE0_SWAUX_CTRL, &buf) &&
+				  !(buf & SWAUX_SEND)))
+			return CB_ERR;
+
+		if (i2c_readb(bus, chip, PAGE0_SWAUX_STATUS, &buf))
+			return CB_ERR;
+
+		switch (buf & SWAUX_STATUS_MASK) {
+		case SWAUX_STATUS_NACK:
+		case SWAUX_STATUS_I2C_NACK:
+		case SWAUX_STATUS_INVALID:
+		case SWAUX_STATUS_TIMEOUT:
+			return CB_ERR;
+		case SWAUX_STATUS_ACKM:
+			length = buf & SWAUX_M_MASK;
+			break;
+		}
+
+		if (length && !dp_aux_request_is_write(request)) {
+			reg = PAGE0_SWAUX_RDATA;
+			for (i = 0; i < length; i++) {
+				if (i2c_readb(bus, chip, reg++, &buf))
+					return CB_ERR;
+				*data++ = buf;
+			}
+		}
+	}
+
+	return CB_SUCCESS;
+}
+
+void ps8640_backlight_enable(uint8_t bus, uint8_t chip)
+{
+	uint8_t val;
+
+	val = DP_BACKLIGHT_CONTROL_MODE_DPCD;
+	ps8640_bridge_aux_request(bus, chip, DP_BACKLIGHT_MODE_SET, 1,
+				  DPCD_WRITE, &val);
+
+	val = 0xff;
+	ps8640_bridge_aux_request(bus, chip, DP_BACKLIGHT_BRIGHTNESS_MSB, 1,
+				  DPCD_WRITE, &val);
+
+	val = DP_BACKLIGHT_ENABLE;
+	ps8640_bridge_aux_request(bus, chip, DP_DISPLAY_CONTROL_REGISTER, 1,
+				  DPCD_WRITE, &val);
+}
diff --git a/src/drivers/parade/ps8640/ps8640.h b/src/drivers/parade/ps8640/ps8640.h
index 06daad4e3abc..fb78be6bd7cb 100644
--- a/src/drivers/parade/ps8640/ps8640.h
+++ b/src/drivers/parade/ps8640/ps8640.h
@@ -24,11 +24,33 @@ enum {
 };
 
 enum {
-	EDID_LENGTH         = 128,
-	EDID_I2C_ADDR       = 0x50,
-	EDID_EXTENSION_FLAG = 0x7e,
+	PAGE0_AUXCH_CFG3 = 0x76,
+	AUXCH_CFG3_RESET = 0xff,
+	PAGE0_SWAUX_ADDR_7_0 = 0x7d,
+	PAGE0_SWAUX_ADDR_15_8 = 0x7e,
+	PAGE0_SWAUX_ADDR_23_16 = 0x7f,
+	SWAUX_ADDR_MASK = 0xfffff,
+	PAGE0_SWAUX_LENGTH = 0x80,
+	SWAUX_LENGTH_MASK = 0xf,
+	SWAUX_NO_PAYLOAD = BIT(7),
+	PAGE0_SWAUX_WDATA = 0x81,
+	PAGE0_SWAUX_RDATA = 0x82,
+	PAGE0_SWAUX_CTRL = 0x83,
+	SWAUX_SEND = BIT(0),
+	PAGE0_SWAUX_STATUS = 0x84,
+	SWAUX_M_MASK = 0x1f,
+	SWAUX_STATUS_MASK = (0x7 << 5),
+	SWAUX_STATUS_NACK = (0x1 << 5),
+	SWAUX_STATUS_DEFER = (0x2 << 5),
+	SWAUX_STATUS_ACKM = (0x3 << 5),
+	SWAUX_STATUS_INVALID = (0x4 << 5),
+	SWAUX_STATUS_I2C_NACK = (0x5 << 5),
+	SWAUX_STATUS_I2C_DEFER = (0x6 << 5),
+	SWAUX_STATUS_TIMEOUT = (0x7 << 5),
 };
 
 int ps8640_init(uint8_t bus, uint8_t chip);
 int ps8640_get_edid(uint8_t bus, uint8_t chip, struct edid *out);
+void ps8640_backlight_enable(uint8_t bus, uint8_t chip);
+
 #endif
diff --git a/src/drivers/ti/sn65dsi86bridge/sn65dsi86bridge.c b/src/drivers/ti/sn65dsi86bridge/sn65dsi86bridge.c
index 2ba09775478f..c4c40880237e 100644
--- a/src/drivers/ti/sn65dsi86bridge/sn65dsi86bridge.c
+++ b/src/drivers/ti/sn65dsi86bridge/sn65dsi86bridge.c
@@ -4,6 +4,7 @@
 #include <delay.h>
 #include <endian.h>
 #include <device/i2c_simple.h>
+#include <dp_aux.h>
 #include <edid.h>
 #include <timer.h>
 #include <types.h>
@@ -31,14 +32,6 @@
 #define DP_MAX_SUPPORTED_RATES		8 /* 16-bit little-endian */
 #define DP_LANE_COUNT_MASK		0xf
 
-/* Backlight configuration */
-#define DP_BACKLIGHT_MODE_SET			0x721
-#define DP_BACKLIGHT_CONTROL_MODE_MASK		0x3
-#define DP_BACKLIGHT_CONTROL_MODE_DPCD		0x2
-#define DP_DISPLAY_CONTROL_REGISTER		0x720
-#define DP_BACKLIGHT_ENABLE			0x1
-#define DP_BACKLIGHT_BRIGHTNESS_MSB		0x722
-
 /* link configuration */
 #define DP_LINK_BW_SET		0x100
 #define DP_LINK_BW_1_62		0x06
@@ -132,17 +125,6 @@ enum vstream_config {
 	VSTREAM_ENABLE = 1,
 };
 
-enum i2c_over_aux {
-	I2C_OVER_AUX_WRITE_MOT_0 = 0x0,
-	I2C_OVER_AUX_READ_MOT_0 = 0x1,
-	I2C_OVER_AUX_WRITE_STATUS_UPDATE_0 = 0x2,
-	I2C_OVER_AUX_WRITE_MOT_1 = 0x4,
-	I2C_OVER_AUX_READ_MOT_1 = 0x5,
-	I2C_OVER_AUX_WRITE_STATUS_UPDATE_1 = 0x6,
-	NATIVE_AUX_WRITE = 0x8,
-	NATIVE_AUX_READ = 0x9,
-};
-
 enum aux_cmd_status {
 	NAT_I2C_FAIL = 1 << 6,
 	AUX_SHORT = 1 << 5,
@@ -166,21 +148,6 @@ enum ml_tx_mode {
 	REDRIVER_SEMI_AUTO_LINK_TRAINING = 0xb,
 };
 
-enum aux_request {
-	DPCD_READ,
-	DPCD_WRITE,
-	I2C_RAW_READ,
-	I2C_RAW_WRITE,
-	I2C_RAW_READ_AND_STOP,
-	I2C_RAW_WRITE_AND_STOP,
-};
-
-enum {
-	EDID_LENGTH = 128,
-	EDID_I2C_ADDR = 0x50,
-	EDID_EXTENSION_FLAG = 0x7e,
-};
-
 /*
  * LUT index corresponds to register value and LUT values corresponds
  * to dp data rate supported by the bridge in Mbps unit.
@@ -189,41 +156,6 @@ static const unsigned int sn65dsi86_bridge_dp_rate_lut[] = {
 	0, 1620, 2160, 2430, 2700, 3240, 4320, 5400
 };
 
-static bool request_is_write(enum aux_request request)
-{
-	switch (request) {
-	case I2C_RAW_WRITE_AND_STOP:
-	case I2C_RAW_WRITE:
-	case DPCD_WRITE:
-		return true;
-	default:
-		return false;
-	}
-}
-
-static enum i2c_over_aux get_aux_cmd(enum aux_request request, uint32_t remaining_after_this)
-{
-	switch (request) {
-	case I2C_RAW_WRITE_AND_STOP:
-		if (!remaining_after_this)
-			return I2C_OVER_AUX_WRITE_MOT_0;
-		/* fallthrough */
-	case I2C_RAW_WRITE:
-		return I2C_OVER_AUX_WRITE_MOT_1;
-	case I2C_RAW_READ_AND_STOP:
-		if (!remaining_after_this)
-			return I2C_OVER_AUX_READ_MOT_0;
-		/* fallthrough */
-	case I2C_RAW_READ:
-		return I2C_OVER_AUX_READ_MOT_1;
-	case DPCD_WRITE:
-		return NATIVE_AUX_WRITE;
-	case DPCD_READ:
-	default:
-		return NATIVE_AUX_READ;
-	}
-}
-
 static cb_err_t sn65dsi86_bridge_aux_request(uint8_t bus,
 					     uint8_t chip,
 					     unsigned int target_reg,
@@ -241,10 +173,10 @@ static cb_err_t sn65dsi86_bridge_aux_request(uint8_t bus,
 		   NAT_I2C_FAIL | AUX_SHORT | AUX_DFER | AUX_RPLY_TOUT | SEND_INT);
 
 	while (total_size) {
-		length = MIN(total_size, 16);
+		length = MIN(total_size, DP_AUX_MAX_PAYLOAD_BYTES);
 		total_size -= length;
 
-		enum i2c_over_aux cmd = get_aux_cmd(request, total_size);
+		enum i2c_over_aux cmd = dp_get_aux_cmd(request, total_size);
 		if (i2c_writeb(bus, chip, SN_AUX_CMD_REG, (cmd << 4)) ||
 		    i2c_writeb(bus, chip, SN_AUX_ADDR_19_16_REG, (target_reg >> 16) & 0xF) ||
 		    i2c_writeb(bus, chip, SN_AUX_ADDR_15_8_REG, (target_reg >> 8) & 0xFF) ||
@@ -252,7 +184,7 @@ static cb_err_t sn65dsi86_bridge_aux_request(uint8_t bus,
 		    i2c_writeb(bus, chip, SN_AUX_LENGTH_REG, length))
 			return CB_ERR;
 
-		if (request_is_write(request)) {
+		if (dp_aux_request_is_write(request)) {
 			reg = SN_AUX_WDATA_REG_0;
 			for (i = 0; i < length; i++)
 				if (i2c_writeb(bus, chip, reg++, *data++))
@@ -273,7 +205,7 @@ static cb_err_t sn65dsi86_bridge_aux_request(uint8_t bus,
 			return CB_ERR;
 		}
 
-		if (!request_is_write(request)) {
+		if (!dp_aux_request_is_write(request)) {
 			reg = SN_AUX_RDATA_REG_0;
 			for (i = 0; i < length; i++) {
 				if (i2c_readb(bus, chip, reg++, &buf))
diff --git a/src/include/dp_aux.h b/src/include/dp_aux.h
new file mode 100644
index 000000000000..ce93383a637e
--- /dev/null
+++ b/src/include/dp_aux.h
@@ -0,0 +1,48 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef _DP_AUX_H_
+#define _DP_AUX_H_
+
+#include <types.h>
+
+enum {
+	EDID_LENGTH         = 128,
+	EDID_I2C_ADDR       = 0x50,
+	EDID_EXTENSION_FLAG = 0x7e,
+};
+
+enum i2c_over_aux {
+	I2C_OVER_AUX_WRITE_MOT_0 = 0x0,
+	I2C_OVER_AUX_READ_MOT_0 = 0x1,
+	I2C_OVER_AUX_WRITE_STATUS_UPDATE_0 = 0x2,
+	I2C_OVER_AUX_WRITE_MOT_1 = 0x4,
+	I2C_OVER_AUX_READ_MOT_1 = 0x5,
+	I2C_OVER_AUX_WRITE_STATUS_UPDATE_1 = 0x6,
+	NATIVE_AUX_WRITE = 0x8,
+	NATIVE_AUX_READ = 0x9,
+};
+
+enum aux_request {
+	DPCD_READ,
+	DPCD_WRITE,
+	I2C_RAW_READ,
+	I2C_RAW_WRITE,
+	I2C_RAW_READ_AND_STOP,
+	I2C_RAW_WRITE_AND_STOP,
+};
+
+/* Backlight configuration */
+#define DP_BACKLIGHT_MODE_SET			0x721
+#define DP_BACKLIGHT_CONTROL_MODE_MASK		0x3
+#define DP_BACKLIGHT_CONTROL_MODE_DPCD		0x2
+#define DP_DISPLAY_CONTROL_REGISTER		0x720
+#define DP_BACKLIGHT_ENABLE			0x1
+#define DP_BACKLIGHT_BRIGHTNESS_MSB		0x722
+
+#define DP_AUX_MAX_PAYLOAD_BYTES	16
+
+
+bool dp_aux_request_is_write(enum aux_request request);
+enum i2c_over_aux dp_get_aux_cmd(enum aux_request request, uint32_t remaining_after_this);
+
+#endif
diff --git a/src/lib/Makefile.inc b/src/lib/Makefile.inc
index 693a526b66f8..0f96aebd7ebb 100644
--- a/src/lib/Makefile.inc
+++ b/src/lib/Makefile.inc
@@ -147,6 +147,7 @@ ramstage-$(CONFIG_BOOTSPLASH) += bootsplash.c
 ramstage-$(CONFIG_BOOTSPLASH) += jpeg.c
 ramstage-$(CONFIG_COLLECT_TIMESTAMPS) += timestamp.c
 ramstage-$(CONFIG_COVERAGE) += libgcov.c
+ramstage-y += dp_aux.c
 ramstage-y += edid.c
 ramstage-y += edid_fill_fb.c
 ramstage-y += memrange.c
diff --git a/src/lib/dp_aux.c b/src/lib/dp_aux.c
new file mode 100644
index 000000000000..ee3ac8ab00ab
--- /dev/null
+++ b/src/lib/dp_aux.c
@@ -0,0 +1,41 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <delay.h>
+#include <dp_aux.h>
+#include <console/console.h>
+#include <timer.h>
+
+bool dp_aux_request_is_write(enum aux_request request)
+{
+	switch (request) {
+	case I2C_RAW_WRITE_AND_STOP:
+	case I2C_RAW_WRITE:
+	case DPCD_WRITE:
+		return true;
+	default:
+		return false;
+	}
+}
+
+enum i2c_over_aux dp_get_aux_cmd(enum aux_request request, uint32_t remaining_after_this)
+{
+	switch (request) {
+	case I2C_RAW_WRITE_AND_STOP:
+		if (!remaining_after_this)
+			return I2C_OVER_AUX_WRITE_MOT_0;
+		/* fallthrough */
+	case I2C_RAW_WRITE:
+		return I2C_OVER_AUX_WRITE_MOT_1;
+	case I2C_RAW_READ_AND_STOP:
+		if (!remaining_after_this)
+			return I2C_OVER_AUX_READ_MOT_0;
+		/* fallthrough */
+	case I2C_RAW_READ:
+		return I2C_OVER_AUX_READ_MOT_1;
+	case DPCD_WRITE:
+		return NATIVE_AUX_WRITE;
+	case DPCD_READ:
+	default:
+		return NATIVE_AUX_READ;
+	}
+}