From 026703174a2cf8cd9c83a7c797b96b95af5af69b Mon Sep 17 00:00:00 2001
From: Biwen Li <biwen.li@nxp.com>
Date: Mon, 12 Oct 2020 20:07:35 +0800
Subject: [PATCH] board/freescale/vid: enables writes to all commands for
 LTC3882

Enable writes to all commands for LTC3882

Signed-off-by: Biwen Li <biwen.li@nxp.com>
Reviewed-by: Priyanka Jain <priyanka.jain@nxp.com>
---
 board/freescale/common/vid.c | 42 +++++++++++++++++++++++++++++++++---
 board/freescale/common/vid.h | 19 ++++++++++++++++
 2 files changed, 58 insertions(+), 3 deletions(-)

diff --git a/board/freescale/common/vid.c b/board/freescale/common/vid.c
index bf8a5d893f..9c51f50260 100644
--- a/board/freescale/common/vid.c
+++ b/board/freescale/common/vid.c
@@ -379,6 +379,7 @@ static int set_voltage_to_LTC(int i2caddress, int vdd)
 {
 	int ret, vdd_last, vdd_target = vdd;
 	int count = 100, temp = 0;
+	unsigned char value;
 
 	/* Scale up to the LTC resolution is 1/4096V */
 	vdd = (vdd * 4096) / 1000;
@@ -391,16 +392,51 @@ static int set_voltage_to_LTC(int i2caddress, int vdd)
 
 	/* Write the desired voltage code to the regulator */
 #ifndef CONFIG_DM_I2C
+	/* Check write protect state */
+	ret = i2c_read(I2C_VOL_MONITOR_ADDR,
+		       PMBUS_CMD_WRITE_PROTECT, 1,
+		       (void *)&value, sizeof(value));
+	if (ret)
+		goto exit;
+
+	if (value != EN_WRITE_ALL_CMD) {
+		value = EN_WRITE_ALL_CMD;
+		ret = i2c_write(I2C_VOL_MONITOR_ADDR,
+				PMBUS_CMD_WRITE_PROTECT, 1,
+				(void *)&value, sizeof(value));
+		if (ret)
+			goto exit;
+	}
+
 	ret = i2c_write(I2C_VOL_MONITOR_ADDR,
-			PMBUS_CMD_PAGE_PLUS_WRITE, 1, (void *)&buff, 5);
+			PMBUS_CMD_PAGE_PLUS_WRITE, 1,
+			(void *)&buff, sizeof(buff));
 #else
 	struct udevice *dev;
 
 	ret = i2c_get_chip_for_busnum(0, I2C_VOL_MONITOR_ADDR, 1, &dev);
-	if (!ret)
+	if (!ret) {
+		/* Check write protect state */
+		ret = dm_i2c_read(dev,
+				  PMBUS_CMD_WRITE_PROTECT,
+				  (void *)&value, sizeof(value));
+		if (ret)
+			goto exit;
+
+		if (value != EN_WRITE_ALL_CMD) {
+			value = EN_WRITE_ALL_CMD;
+			ret = dm_i2c_write(dev,
+					   PMBUS_CMD_WRITE_PROTECT,
+					   (void *)&value, sizeof(value));
+			if (ret)
+				goto exit;
+		}
+
 		ret = dm_i2c_write(dev, PMBUS_CMD_PAGE_PLUS_WRITE,
-				   (void *)&buff, 5);
+				   (void *)&buff, sizeof(buff));
+	}
 #endif
+exit:
 	if (ret) {
 		printf("VID: I2C failed to write to the volatge regulator\n");
 		return -1;
diff --git a/board/freescale/common/vid.h b/board/freescale/common/vid.h
index 99778e9a93..65b348ee42 100644
--- a/board/freescale/common/vid.h
+++ b/board/freescale/common/vid.h
@@ -18,6 +18,25 @@
 /* step the IR regulator in 5mV increments */
 #define IR_VDD_STEP_DOWN		5
 #define IR_VDD_STEP_UP			5
+
+/* LTC3882 */
+#define PMBUS_CMD_WRITE_PROTECT         0x10
+/*
+ * WRITE_PROTECT command supported values
+ * 0x80: Disable all writes except WRITE_PROTECT, PAGE,
+ *       STORE_USER_ALL and MFR_EE_UNLOCK commands.
+ * 0x40: Disable all writes except WRITE_PROTECT, PAGE, STORE_USER_ALL,
+ *       MFR_EE_UNLOCK, OPERATION, CLEAR_PEAKS and CLEAR_FAULTS commands.
+ *       Individual faults can also be cleared by writing a 1 to the
+ *       respective status bit.
+ * 0x20: Disable all writes except WRITE_PROTECT, PAGE, STORE_USER_ ALL,
+ *       MFR_EE_UNLOCK, OPERATION, CLEAR_PEAKS, CLEAR_FAULTS, ON_OFF_CONFIG
+ *       and VOUT_COMMAND commands. Individual faults can be cleared by
+ *       writing a 1 to the respective status bit.
+ * 0x00: Enables write to all commands
+ */
+#define EN_WRITE_ALL_CMD (0)
+
 int adjust_vdd(ulong vdd_override);
 
 #endif  /* __VID_H_ */