power: supply: bq25890: support IBAT compensation

Add configuration for compensation of IBAT measuring resistor in series
with the battery.
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

drivers/power/supply/bq25890_charger.c

@@ -83,6 +83,8 @@ struct bq25890_init_data {
 	u8 boostf;	/* boost frequency		*/
 	u8 ilim_en;	/* enable ILIM pin		*/
 	u8 treg;	/* thermal regulation threshold */
+	u8 rbatcomp;	/* IBAT sense resistor value    */
+	u8 vclamp;	/* IBAT compensation voltage limit */
 };
 
 struct bq25890_state {
@@ -258,6 +260,8 @@ enum bq25890_table_ids {
 	TBL_VREG,
 	TBL_BOOSTV,
 	TBL_SYSVMIN,
+	TBL_VBATCOMP,
+	TBL_RBATCOMP,
 
 	/* lookup tables */
 	TBL_TREG,
@@ -299,6 +303,8 @@ static const union {
 	[TBL_VREG] =	{ .rt = {3840000, 4608000, 16000} },	 /* uV */
 	[TBL_BOOSTV] =	{ .rt = {4550000, 5510000, 64000} },	 /* uV */
 	[TBL_SYSVMIN] = { .rt = {3000000, 3700000, 100000} },	 /* uV */
+	[TBL_VBATCOMP] ={ .rt = {0,        224000, 32000} },	 /* uV */
+	[TBL_RBATCOMP] ={ .rt = {0,        140000, 20000} },	 /* uOhm */
 
 	/* lookup tables */
 	[TBL_TREG] =	{ .lt = {bq25890_treg_tbl, BQ25890_TREG_TBL_SIZE} },
@@ -648,7 +654,9 @@ static int bq25890_hw_init(struct bq25890_device *bq)
 		{F_BOOSTI,	 bq->init_data.boosti},
 		{F_BOOSTF,	 bq->init_data.boostf},
 		{F_EN_ILIM,	 bq->init_data.ilim_en},
-		{F_TREG,	 bq->init_data.treg}
+		{F_TREG,	 bq->init_data.treg},
+		{F_BATCMP,	 bq->init_data.rbatcomp},
+		{F_VCLAMP,	 bq->init_data.vclamp},
 	};
 
 	ret = bq25890_chip_reset(bq);
@@ -859,11 +867,14 @@ static int bq25890_fw_read_u32_props(struct bq25890_device *bq)
 		{"ti,boost-max-current", false, TBL_BOOSTI, &init->boosti},
 
 		/* optional properties */
-		{"ti,thermal-regulation-threshold", true, TBL_TREG, &init->treg}
+		{"ti,thermal-regulation-threshold", true, TBL_TREG, &init->treg},
+		{"ti,ibatcomp-micro-ohms", true, TBL_RBATCOMP, &init->rbatcomp},
+		{"ti,ibatcomp-clamp-microvolt", true, TBL_VBATCOMP, &init->vclamp},
 	};
 
 	/* initialize data for optional properties */
 	init->treg = 3; /* 120 degrees Celsius */
+	init->rbatcomp = init->vclamp = 0; /* IBAT compensation disabled */
 
 	for (i = 0; i < ARRAY_SIZE(props); i++) {
 		ret = device_property_read_u32(bq->dev, props[i].name,