max17055: Support alert function.

MAX17055 support 4 kinds of alert: voltage, current, state-of-charge,
and temperatore. This CL enables this functionality.

datasheet: https://datasheets.maximintegrated.com/en/ds/MAX17055.pdf

TEST=manually test on Kukui.
BUG=b:111378620
BRANCH=None

Change-Id: I94126fdc541f9456c8f48f42383bc6e2188257e2
Signed-off-by: Yilun Lin <yllin@google.com>
Reviewed-on: https://chromium-review.googlesource.com/1276006
Commit-Ready: Yilun Lin <yllin@chromium.org>
Tested-by: Yilun Lin <yllin@chromium.org>
Reviewed-by: Nicolas Boichat <drinkcat@chromium.org>

3 files changed, 137 insertions, 3 deletions

diff --git a/driver/battery/max17055.c b/driver/battery/max17055.c
index 07ecc473dd..9cdd107d20 100644
--- a/driver/battery/max17055.c
+++ b/driver/battery/max17055.c
@@ -423,6 +423,10 @@ static void max17055_init(void)
 {
 	int reg;
 	int retries = 80;
+#ifdef CONFIG_BATTERY_MAX17055_ALERT
+	const struct max17055_alert_profile *alert_profile =
+		max17055_get_alert_profile();
+#endif
 
 	if (!max17055_probe()) {
 		CPRINTS("Wrong max17055 id!");
@@ -481,6 +485,25 @@ static void max17055_init(void)
 		}
 	}
 
+#ifdef CONFIG_BATTERY_MAX17055_ALERT
+	/* Set voltage alert range */
+	MAX17055_WRITE_DEBUG(REG_VALRTTH, alert_profile->v_alert_mxmn);
+	/* Set temperature alert range */
+	MAX17055_WRITE_DEBUG(REG_TALRTTH, alert_profile->t_alert_mxmn);
+	/* Set state-of-charge alert range */
+	MAX17055_WRITE_DEBUG(REG_SALRTTH, alert_profile->s_alert_mxmn);
+	/* Set current alert range */
+	MAX17055_WRITE_DEBUG(REG_IALRTTH, alert_profile->i_alert_mxmn);
+
+	/* Disable all sticky bits; enable alert AEN */
+	MAX17055_READ_DEBUG(REG_CONFIG, &reg);
+	MAX17055_WRITE_DEBUG(REG_CONFIG, (reg & ~CONF_ALL_STICKY) | CONF_AEN);
+
+	/* Clear alerts */
+	MAX17055_READ_DEBUG(REG_STATUS, &reg);
+	MAX17055_WRITE_DEBUG(REG_STATUS, reg & ~STATUS_ALL_ALRT);
+#endif
+
 	CPRINTS("max17055 configuration succeeded!");
 }
 DECLARE_HOOK(HOOK_INIT, max17055_init, HOOK_PRIO_DEFAULT);
diff --git a/driver/battery/max17055.h b/driver/battery/max17055.h
index 5a3764d9de..f223fa15e8 100644
--- a/driver/battery/max17055.h
+++ b/driver/battery/max17055.h
@@ -12,6 +12,9 @@
 #define MAX17055_DEVICE_ID          0x4010
 
 #define REG_STATUS                  0x00
+#define REG_VALRTTH                 0x01
+#define REG_TALRTTH                 0x02
+#define REG_SALRTTH                 0x03
 #define REG_AT_RATE                 0x04
 #define REG_REMAINING_CAPACITY      0x05
 #define REG_STATE_OF_CHARGE         0x06
@@ -27,6 +30,9 @@
 #define REG_CYCLE_COUNT             0x17
 #define REG_DESIGN_CAPACITY         0x18
 #define REG_AVERAGE_VOLTAGE         0x19
+#define REG_MAX_MIN_TEMP            0x1a
+#define REG_MAX_MIN_VOLT            0x1b
+#define REG_MAX_MIN_CURR            0x1c
 #define REG_CHARGE_TERM_CURRENT     0x1e
 #define REG_TIME_TO_FULL            0x20
 #define REG_DEVICE_NAME             0x21
@@ -42,17 +48,41 @@
 #define REG_DQACC                   0x45
 #define REG_DPACC                   0x46
 #define REG_STATUS2                 0xb0
+#define REG_IALRTTH                 0xb4
 #define REG_HIBCFG                  0xba
 #define REG_CONFIG2                 0xbb
 #define REG_TIMERH                  0xbe
 #define REG_MODELCFG                0xdb
 
 /* Status reg (0x00) flags */
-#define STATUS_POR                  0x0002
-#define STATUS_BST                  0x0008
+#define STATUS_POR                  (1 << 1)
+#define STATUS_IMN                  (1 << 2)
+#define STATUS_BST                  (1 << 3)
+#define STATUS_IMX                  (1 << 6)
+#define STATUS_VMN                  (1 << 8)
+#define STATUS_TMN                  (1 << 9)
+#define STATUS_SMN                  (1 << 10)
+#define STATUS_VMX                  (1 << 12)
+#define STATUS_TMX                  (1 << 13)
+#define STATUS_SMX                  (1 << 14)
+#define STATUS_ALL_ALRT                                                        \
+	(STATUS_IMN | STATUS_IMX | STATUS_VMN | STATUS_VMX | STATUS_TMN |      \
+	 STATUS_TMX | STATUS_SMN | STATUS_SMX)
+
+/* Alert disable values (0x01, 0x02, 0x03, 0xb4) */
+#define VALRT_DISABLE               0xff00
+#define TALRT_DISABLE               0x7f80
+#define SALRT_DISABLE               0xff00
+#define IALRT_DISABLE               0x7f80
 
 /* Config reg (0x1d) flags */
-#define CONF_TSEL                   0x8000
+#define CONF_AEN                    (1 << 2)
+#define CONF_IS                     (1 << 11)
+#define CONF_VS                     (1 << 12)
+#define CONF_TS                     (1 << 13)
+#define CONF_SS                     (1 << 14)
+#define CONF_TSEL                   (1 << 15)
+#define CONF_ALL_STICKY             (CONF_IS | CONF_VS | CONF_TS | CONF_SS)
 
 /* FStat reg (0x3d) flags */
 #define FSTAT_DNR                   0x0001
@@ -86,6 +116,27 @@
 #define MAX17055_VEMPTY_REG(ve_mv, vr_mv) \
 	(((ve_mv / 10) << 7) | (vr_mv / 40))
 
+#define MAX17055_MAX_MIN_REG(mx, mn) ((((int16_t)(mx)) << 8) | ((mn)))
+/* Converts voltages alert range for VALRTTH_REG */
+#define MAX17055_VALRTTH_RESOLUTION 20
+#define MAX17055_VALRTTH_REG(mx, mn)                                           \
+	MAX17055_MAX_MIN_REG((uint8_t)(mx / MAX17055_VALRTTH_RESOLUTION),      \
+			     (uint8_t)(mn / MAX17055_VALRTTH_RESOLUTION))
+/* Converts temperature alert range for TALRTTH_REG */
+#define MAX17055_TALRTTH_REG(mx, mn)                                           \
+	MAX17055_MAX_MIN_REG((int8_t)(mx), (int8_t)(mn))
+/* Converts state-of-charge alert range for SALRTTH_REG */
+#define MAX17055_SALRTTH_REG(mx, mn)                                           \
+	MAX17055_MAX_MIN_REG((uint8_t)(mx), (uint8_t)(mn))
+/* Converts current alert range for IALRTTH_REG */
+/* Current resolution: 0.4mV/RSENSE */
+#define MAX17055_IALRTTH_MUL (10 * BATTERY_MAX17055_RSENSE)
+#define MAX17055_IALRTTH_DIV 4
+#define MAX17055_IALRTTH_REG(mx, mn)                                           \
+	MAX17055_MAX_MIN_REG(                                                  \
+		(int8_t)(mx * MAX17055_IALRTTH_MUL / MAX17055_IALRTTH_DIV),    \
+		(int8_t)(mn * MAX17055_IALRTTH_MUL / MAX17055_IALRTTH_DIV))
+
 /*
  * max17055 needs some special battery parameters for fuel gauge
  * learning algorithm. Maxim can help characterize the battery pack
@@ -127,4 +178,58 @@ struct max17055_batt_profile {
 /* Return the special battery parameters max17055 needs. */
 const struct max17055_batt_profile *max17055_get_batt_profile(void);
 
+#ifdef CONFIG_BATTERY_MAX17055_ALERT
+/*
+ * max17055 supports alert on voltage, current, state-of-charge, and
+ * temperature.  To enable this feature, the information of the limit range is
+ * needed.
+ */
+struct max17055_alert_profile {
+	/*
+	 * Sets voltage upper and lower limits that generate an alert if
+	 * voltage is outside of the v_alert_mxmn range.
+	 * The upper 8 bits set the maximum value and the lower 8 bits set the
+	 * minimum value. Interrupt threshold limits are selectable with 20mV
+	 * resolution.
+	 * Use MAX17055_VALRTTH_REG(max, min) to setup the desired range,
+	 * VALRT_DISABLE to disable the alert.
+	 */
+	const uint16_t v_alert_mxmn;
+	/*
+	 * Sets temperature upper and lower limits that generate an alert if
+	 * temperature is outside of the t_alert_mxmn range.
+	 * The upper 8 bits set the maximum value and the lower 8 bits set the
+	 * minimum value. Interrupt threshold limits are stored in
+	 * 2’s-complement format with 1°C resolution.
+	 * Use MAX17055_TALRTTH_REG(max, min) to setup the desired range,
+	 * TALRT_DISABLE to disable the alert.
+	 */
+	const uint16_t t_alert_mxmn;
+	/*
+	 * Sets reported state-of-charge upper and lower limits that generate
+	 * an alert if SOC is outside of the s_alert_mxmn range.
+	 * The upper 8 bits set the maximum value and the lower 8 bits set the
+	 * minimum value. Interrupt threshold limits are configurable with 1%
+	 * resolution.
+	 * Use MAX17055_SALRTTH_REG(max, min) to setup the desired range,
+	 * SALRT_DISABLE to disable the alert.
+	 */
+	const uint16_t s_alert_mxmn;
+	/*
+	 * Sets current upper and lower limits that generate an alert if
+	 * current is outside of the i_alert_mxmn range.
+	 * The upper 8 bits set the maximum value and the lower 8 bits set the
+	 * minimum value. Interrupt threshold limits are selectable with
+	 * 0.4mV/R SENSE resolution.
+	 * Use MAX17055_IALRTTH_REG(max, min) to setup the desired range,
+	 * IALRT_DISABLE to disable the alert.
+	 */
+	const uint16_t i_alert_mxmn;
+};
+
+/*
+ * Return the battery/system's alert threshoulds that max17055 needs.
+ */
+const struct max17055_alert_profile *max17055_get_alert_profile(void);
+#endif /* CONFIG_BATTERY_MAX17055_ALERT */
 #endif /* __CROS_EC_MAX17055_H */
diff --git a/include/config.h b/include/config.h
index e5eeb7d7e1..eb40d5e48c 100644
--- a/include/config.h
+++ b/include/config.h
@@ -275,6 +275,12 @@
 #undef CONFIG_BATTERY_BQ4050
 #undef CONFIG_BATTERY_MAX17055
 
+/*
+ * MAX17055 support alert on voltage, current, temperature, and state-of-charge.
+ */
+#undef CONFIG_BATTERY_MAX17055_ALERT
+
+
 /* Compile mock battery support; used by tests. */
 #undef CONFIG_BATTERY_MOCK