From 9aee2a19e81949eca86eb0b113c99d1782eaa2d2 Mon Sep 17 00:00:00 2001
From: Philip Chen <philipchen@google.com>
Date: Mon, 19 Mar 2018 13:47:05 -0700
Subject: [PATCH] battery/max17055: Implement battery_status()

BUG=b:74841068
BRANCH=scarlet
TEST='/sys/class/power_supply/sbs-9-000b/status' shows
discharging/charging/full status correctly

Change-Id: I4216ba2d95ac82a9f600d8685d993cb5b37206d8
Signed-off-by: Philip Chen <philipchen@google.com>
Reviewed-on: https://chromium-review.googlesource.com/969747
Commit-Ready: ChromeOS CL Exonerator Bot <chromiumos-cl-exonerator@appspot.gserviceaccount.com>
Tested-by: Philip Chen <philipchen@chromium.org>
Reviewed-by: Aseda Aboagye <aaboagye@chromium.org>
---
 driver/battery/max17055.c | 22 +++++++++++++++++++++-
 driver/battery/max17055.h |  5 +++++
 2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/driver/battery/max17055.c b/driver/battery/max17055.c
index 9be2a14651..e02a4aaa42 100644
--- a/driver/battery/max17055.c
+++ b/driver/battery/max17055.c
@@ -197,7 +197,24 @@ int battery_get_mode(int *mode)
 
 int battery_status(int *status)
 {
-	return EC_ERROR_UNIMPLEMENTED;
+	int rv;
+	int reg;
+
+	*status = 0;
+
+	rv = max17055_read(REG_FSTAT, &reg);
+	if (rv)
+		return rv;
+	if (reg & FSTAT_FQ)
+		*status |= BATTERY_FULLY_CHARGED;
+
+	rv = max17055_read(REG_CURRENT, &reg);
+	if (rv)
+		return rv;
+	if (reg >> 15)
+		*status |= BATTERY_DISCHARGING;
+
+	return EC_SUCCESS;
 }
 
 enum battery_present battery_is_present(void)
@@ -267,6 +284,9 @@ void battery_get_params(struct batt_params *batt)
 	    batt->desired_current &&
 	    batt->state_of_charge < BATTERY_LEVEL_FULL)
 		batt->flags |= BATT_FLAG_WANT_CHARGE;
+
+	if (battery_status(&batt->status))
+		batt->flags |= BATT_FLAG_BAD_STATUS;
 }
 
 #ifdef CONFIG_CMD_PWR_AVG
diff --git a/driver/battery/max17055.h b/driver/battery/max17055.h
index fb49e69c22..be070e9896 100644
--- a/driver/battery/max17055.h
+++ b/driver/battery/max17055.h
@@ -54,11 +54,16 @@
 
 /* FStat reg (0x3d) flags */
 #define FSTAT_DNR                   0x0001
+#define FSTAT_FQ                    0x0080
 
 /* ModelCfg reg (0xdb) flags */
 #define MODELCFG_REFRESH            0x8000
 #define MODELCFG_VCHG               0x0400
 
+/* Smart battery status bits (sbs reg 0x16) */
+#define BATTERY_DISCHARGING         0x40
+#define BATTERY_FULLY_CHARGED       0x20
+
 /*
  * Before we have the battery fully characterized, we use these macros to
  * convert basic battery parameters to max17055 reg values for ez config.