MAX17055: Add the full model driver

This patch adds the full model driver for MAX17055. The full model of
MAX17055 provides more accurate soc estimation than the short model or
ez model.

BUG=b:130979269
BRANCH=none
TEST=Do a full charge test

Change-Id: I4cf249cf0c47fd30f75f4e38b74c7995285603e6
Signed-off-by: YH Lin <yueherngl@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/1577387
Commit-Ready: Daisuke Nojiri <dnojiri@chromium.org>
Tested-by: Daisuke Nojiri <dnojiri@chromium.org>
Reviewed-by: Daisuke Nojiri <dnojiri@chromium.org>

3 files changed, 214 insertions, 19 deletions

diff --git a/driver/battery/max17055.c b/driver/battery/max17055.c
index b022b24655..28a2ba1038 100644
--- a/driver/battery/max17055.c
+++ b/driver/battery/max17055.c
@@ -346,16 +346,191 @@ int battery_wait_for_stable(void)
 	return EC_SUCCESS;
 }
 
-/* Configured MAX17055 with the battery parameters for optimal performance. */
-static int max17055_load_batt_model(void)
+static int max17055_poll_flag_clear(int regno, int mask, int timeout)
+{
+	int reg;
+
+	do {
+		if (max17055_read(regno, &reg))
+			return EC_ERROR_UNKNOWN;
+
+		if (!(mask & reg))
+			return EC_SUCCESS;
+
+		msleep(10);
+		timeout -= 10;
+	} while (timeout > 0);
+
+	return EC_ERROR_TIMEOUT;
+}
+
+static int max17055_load_ocv_table(const struct max17055_batt_profile *config)
+{
+	int i;
+	int reg;
+	int retries = 3;
+
+	/* Unlock ocv table */
+	if (max17055_write(REG_LOCK1, 0x0059) ||
+	    max17055_write(REG_LOCK2, 0x00c4))
+		return EC_ERROR_UNKNOWN;
+
+	ASSERT(config->ocv_table);
+
+	/* Write ocv data */
+	for (i = 0; i < MAX17055_OCV_TABLE_SIZE; i++) {
+		if (max17055_write(REG_OCV_TABLE_START + i,
+				   config->ocv_table[i]))
+			return EC_ERROR_UNKNOWN;
+	}
+
+	/* Read and compare ocv data */
+	for (i = 0; i < MAX17055_OCV_TABLE_SIZE; i++) {
+		if (max17055_read(REG_OCV_TABLE_START + i, &reg) ||
+		    reg != config->ocv_table[i])
+			return EC_ERROR_UNKNOWN;
+	}
+
+	while (--retries) {
+		/* Lock ocv table */
+		if (max17055_write(REG_LOCK1, 0x0000) ||
+		    max17055_write(REG_LOCK2, 0x0000))
+			return EC_ERROR_UNKNOWN;
+
+		/*
+		 * If the ocv table remains unlocked, the MAX17055 cannot
+		 * monitor the capacity of the battery. Therefore, it is very
+		 * critical that the ocv table is locked. To verify it is
+		 * locked, simply read back the values. However, this time,
+		 * all values should be read as 0x0000.
+		 */
+		for (i = 0; i < MAX17055_OCV_TABLE_SIZE; i++) {
+			reg = 0xff;
+			if (max17055_read(REG_OCV_TABLE_START + i, &reg))
+				return EC_ERROR_UNKNOWN;
+			if (reg)
+				break;
+		}
+		if (i == MAX17055_OCV_TABLE_SIZE)
+			break;
+		msleep(20);
+	}
+	if (!retries)
+		return EC_ERROR_TIMEOUT;
+
+	/*
+	 * Delay 180ms is to prepare the environment to load the custom
+	 * battery parameters. Otherwise, the initialization operation
+	 * has a very small probability of failure.
+	 */
+	msleep(180);
+
+	return EC_SUCCESS;
+}
+
+static int max17055_exit_hibernate(void)
+{
+	/*
+	 * Write REG_COMMAND with 0x90 to force the firmware to stop running.
+	 * Write REG_HIBCFG with 0x00 to exit hibernate mode immediately.
+	 * Write REG_COMMAND with 0x00 to run the firmware again.
+	 */
+	if (max17055_write(REG_COMMAND, 0x90) ||
+	    max17055_write(REG_HIBCFG, 0x00) ||
+	    max17055_write(REG_COMMAND, 0x00))
+		return EC_ERROR_UNKNOWN;
+
+	return EC_SUCCESS;
+}
+
+/* Configured MAX17055 with the battery parameters for full model. */
+static int max17055_load_batt_model_full(void)
 {
 	int reg;
 	int hib_cfg;
+
+	const struct max17055_batt_profile *config;
+
+	config = max17055_get_batt_profile();
+
+	/* Store the original HibCFG value. */
+	if (max17055_read(REG_HIBCFG, &hib_cfg))
+		return EC_ERROR_UNKNOWN;
+
+	/* Force exit from hibernate */
+	if (max17055_exit_hibernate())
+		return EC_ERROR_UNKNOWN;
+
+	/* Write LearnCFG with LS 7 */
+	if (max17055_write(REG_LEARNCFG, config->learn_cfg | 0x0070))
+		return EC_ERROR_UNKNOWN;
+
+	/*
+	 * Unlock ocv table access, write/compare/verify custom ocv table,
+	 * lock ocv table access.
+	 */
+	if (max17055_load_ocv_table(config))
+		return EC_ERROR_UNKNOWN;
+
+	/* Write custom parameters */
+	if (max17055_write(REG_DESIGN_CAPACITY, config->design_cap) ||
+	    max17055_write(REG_DQACC, config->design_cap >> 4) ||
+	    max17055_write(REG_DPACC, 0x0c80) ||
+	    max17055_write(REG_CHARGE_TERM_CURRENT, config->ichg_term) ||
+	    max17055_write(REG_EMPTY_VOLTAGE, config->v_empty_detect))
+		return EC_ERROR_UNKNOWN;
+
+	if (max17055_write(REG_RCOMP0, config->rcomp0) ||
+	    max17055_write(REG_TEMPCO, config->tempco) ||
+	    max17055_write(REG_QR_TABLE00, config->qr_table00) ||
+	    max17055_write(REG_QR_TABLE10, config->qr_table10))
+		return EC_ERROR_UNKNOWN;
+
+	/* Update required capacity registers */
+	if (max17055_write(REG_REMAINING_CAPACITY, 0x0000) ||
+	    max17055_read(REG_VFSOC, &reg))
+		return EC_ERROR_UNKNOWN;
+
+	if (max17055_write(REG_VFSOC0, reg) ||
+	    max17055_write(REG_FULL_CHARGE_CAPACITY, config->design_cap) ||
+	    max17055_write(REG_FULLCAPNOM, config->design_cap))
+		return EC_ERROR_UNKNOWN;
+
+	/* Prepare to Load Model */
+	if (max17055_write(REG_REMAINING_CAPACITY, 0x0000) ||
+	    max17055_write(REG_MIXCAP, config->design_cap))
+		return EC_ERROR_UNKNOWN;
+
+	/* Initiate model loading */
+	if (max17055_read(REG_CONFIG2, &reg) ||
+	    max17055_write(REG_CONFIG2, reg | CONFIG2_LDMDL))
+		return EC_ERROR_UNKNOWN;
+
+	if (max17055_poll_flag_clear(REG_CONFIG2, CONFIG2_LDMDL, 500))
+		return EC_ERROR_UNKNOWN;
+
+	/* Write LearnCFG with LS 0 */
+	if (max17055_write(REG_LEARNCFG, config->learn_cfg & 0xff8f) ||
+	    max17055_write(REG_QR_TABLE20, config->qr_table20) ||
+	    max17055_write(REG_QR_TABLE30, config->qr_table30))
+		return EC_ERROR_UNKNOWN;
+
+	/* Restore the original HibCFG value. */
+	if (max17055_write(REG_HIBCFG, hib_cfg))
+		return EC_ERROR_UNKNOWN;
+
+	return EC_SUCCESS;
+}
+
+/*
+ * Configured MAX17055 with the battery parameters for short model or ez model
+ */
+static int max17055_load_batt_model_short_or_ez(void)
+{
+	int hib_cfg;
 	int dqacc;
 	int dpacc;
 
-	int retries = 50;
-
 	const struct max17055_batt_profile *config;
 
 	config = max17055_get_batt_profile();
@@ -384,10 +559,8 @@ static int max17055_load_batt_model(void)
 	if (max17055_read(REG_HIBCFG, &hib_cfg))
 		return EC_ERROR_UNKNOWN;
 
-	/* Special sequence to exit hibernate mode. */
-	if (max17055_write(0x60, 0x90) ||
-	    max17055_write(REG_HIBCFG, 0) ||
-	    max17055_write(0x60, 0))
+	/* Force exit from hibernate */
+	if (max17055_exit_hibernate())
 		return EC_ERROR_UNKNOWN;
 
 	if (max17055_write(REG_DPACC, dpacc) ||
@@ -395,15 +568,8 @@ static int max17055_load_batt_model(void)
 		return EC_ERROR_UNKNOWN;
 
 	/* Delay up to 500 ms until MODELCFG.REFRESH bit == 0. */
-	while (--retries) {
-		if (max17055_read(REG_MODELCFG, &reg))
-			return EC_ERROR_UNKNOWN;
-		if (!(MODELCFG_REFRESH & reg))
-			break;
-		msleep(10);
-	}
-	if (!retries)
-		return EC_ERROR_TIMEOUT;
+	if (max17055_poll_flag_clear(REG_MODELCFG, MODELCFG_REFRESH, 500))
+		return EC_ERROR_UNKNOWN;
 
 	if (!config->is_ez_config) {
 		if (max17055_write(REG_RCOMP0, config->rcomp0) ||
@@ -421,6 +587,14 @@ static int max17055_load_batt_model(void)
 	return EC_SUCCESS;
 }
 
+static int max17055_load_batt_model(void)
+{
+	if (IS_ENABLED(CONFIG_BATTERY_MAX17055_FULL_MODEL))
+		return max17055_load_batt_model_full();
+	else
+		return max17055_load_batt_model_short_or_ez();
+}
+
 static void max17055_init(void)
 {
 	int reg;
diff --git a/driver/battery/max17055.h b/driver/battery/max17055.h
index ba18af56d5..bdee9ca948 100644
--- a/driver/battery/max17055.h
+++ b/driver/battery/max17055.h
@@ -10,6 +10,7 @@
 
 #define MAX17055_ADDR               0x6c
 #define MAX17055_DEVICE_ID          0x4010
+#define MAX17055_OCV_TABLE_SIZE     48
 
 #define REG_STATUS                  0x00
 #define REG_VALRTTH                 0x01
@@ -22,6 +23,7 @@
 #define REG_VOLTAGE                 0x09
 #define REG_CURRENT                 0x0a
 #define REG_AVERAGE_CURRENT         0x0b
+#define REG_MIXCAP                  0x0f
 #define REG_FULL_CHARGE_CAPACITY    0x10
 #define REG_TIME_TO_EMPTY           0x11
 #define REG_QR_TABLE00              0x12
@@ -37,6 +39,7 @@
 #define REG_TIME_TO_FULL            0x20
 #define REG_DEVICE_NAME             0x21
 #define REG_QR_TABLE10              0x22
+#define REG_FULLCAPNOM              0x23
 #define REG_LEARNCFG                0x28
 #define REG_QR_TABLE20              0x32
 #define REG_RCOMP0                  0x38
@@ -47,12 +50,18 @@
 #define REG_QR_TABLE30              0x42
 #define REG_DQACC                   0x45
 #define REG_DPACC                   0x46
+#define REG_VFSOC0                  0x48
+#define REG_COMMAND                 0x60
+#define REG_LOCK1                   0x62
+#define REG_LOCK2                   0x63
+#define REG_OCV_TABLE_START         0x80
 #define REG_STATUS2                 0xb0
 #define REG_IALRTTH                 0xb4
 #define REG_HIBCFG                  0xba
 #define REG_CONFIG2                 0xbb
 #define REG_TIMERH                  0xbe
 #define REG_MODELCFG                0xdb
+#define REG_VFSOC                   0xff
 
 /* Status reg (0x00) flags */
 #define STATUS_POR                  BIT(1)
@@ -88,9 +97,12 @@
 #define FSTAT_DNR                   0x0001
 #define FSTAT_FQ                    0x0080
 
+/* Config2 reg (0xbb) flags */
+#define CONFIG2_LDMDL               BIT(5)
+
 /* ModelCfg reg (0xdb) flags */
-#define MODELCFG_REFRESH            0x8000
-#define MODELCFG_VCHG               0x0400
+#define MODELCFG_REFRESH            BIT(15)
+#define MODELCFG_VCHG               BIT(10)
 
 /* Smart battery status bits (sbs reg 0x16) */
 #define BATTERY_DISCHARGING         0x40
@@ -173,6 +185,9 @@ struct max17055_batt_profile {
 	 * and v_empty_detect to config max17055 (a.k.a. EZ-config).
 	 */
 	uint8_t is_ez_config;
+
+	/* Used only for full model */
+	const uint16_t *ocv_table;
 };
 
 /* Return the special battery parameters max17055 needs. */
diff --git a/include/config.h b/include/config.h
index bc958572fb..c3d95c243f 100644
--- a/include/config.h
+++ b/include/config.h
@@ -358,6 +358,12 @@
  */
 #undef CONFIG_BATTERY_MAX17055_ALERT
 
+/*
+ * Enable full model driver of MAX17055.
+ *
+ * It provides a better soc estimation. ocv_table needs to be supplied.
+ */
+#undef CONFIG_BATTERY_MAX17055_FULL_MODEL
 
 /* Compile mock battery support; used by tests. */
 #undef CONFIG_BATTERY_MOCK