glados: isl9237: add HW charge ramping

Add HW charge ramping option and enable on glados.
Modify charge_manager to enable/disable HW charge ramping
when option is defined.

Unfortunately, the isl9237 doesn't have a way to determine
what the input current limit has settled on, so the EC will
always report the max input current for that supplier.

BUG=chrome-os-partner:47335
BRANCH=none
TEST=plug in CDP, SDP, DCP, type-C, and PD charger. Make sure
we ramp to a reasonable value for the correct suppliers.
Make sure we don't ramp for type-C and PD chargers.

Change-Id: Ib541fa0be48d8f4d261c71b853b0ee72b2adbf6b
Signed-off-by: Alec Berg <alecaberg@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/311301
Reviewed-by: Shawn N <shawnn@chromium.org>

3 files changed, 79 insertions, 2 deletions

diff --git a/driver/charger/bq2589x.c b/driver/charger/bq2589x.c
index dc4d768275..e36007f16a 100644
--- a/driver/charger/bq2589x.c
+++ b/driver/charger/bq2589x.c
@@ -259,6 +259,23 @@ int charger_post_init(void)
 /* Hardware current ramping (aka ICO: Input Current Optimizer) */
 
 #ifdef CONFIG_CHARGE_RAMP_HW
+int charger_set_hw_ramp(int enable)
+{
+	int val, rv;
+
+	rv = i2c_read8(I2C_PORT_CHARGER, BQ2589X_ADDR, BQ2589X_REG_CFG1, &val);
+	if (rv)
+		return rv;
+
+	if (enable)
+		val |= BQ2589X_CFG1_ICO_EN;
+	else
+		val &= ~BQ2589X_CFG1_ICO_EN;
+
+	return i2c_write8(I2C_PORT_CHARGER, BQ2589X_ADDR, BQ2589X_REG_CFG1,
+			  val);
+}
+
 int chg_ramp_is_stable(void)
 {
 	int val, rv;
diff --git a/driver/charger/bq2589x.h b/driver/charger/bq2589x.h
index 970517f116..ed49aeb661 100644
--- a/driver/charger/bq2589x.h
+++ b/driver/charger/bq2589x.h
@@ -37,6 +37,7 @@
 
 /* REG02 : first configuration register bit definitions */
 #define BQ2589X_CFG1_CONV_START    (1<<7)
+#define BQ2589X_CFG1_ICO_EN        (1<<4)
 #define BQ2589X_CFG1_AUTO_DPDM_EN  (1<<0)
 
 /* REG03 : second configuration register bit definitions */
diff --git a/driver/charger/isl9237.c b/driver/charger/isl9237.c
index 0afb598dda..2d8c78190b 100644
--- a/driver/charger/isl9237.c
+++ b/driver/charger/isl9237.c
@@ -216,15 +216,30 @@ int charger_set_voltage(int voltage)
 
 int charger_post_init(void)
 {
+	int rv, reg;
+
 #ifdef CONFIG_TRICKLE_CHARGING
-	int rv;
 	const struct battery_info *bi = battery_get_info();
 
 	rv = raw_write16(ISL9237_REG_SYS_VOLTAGE_MIN, bi->voltage_min);
 	if (rv)
 		return rv;
 #endif
-	return EC_SUCCESS;
+
+	rv = charger_get_option(&reg);
+	if (rv)
+		return rv;
+
+#ifdef CONFIG_CHARGE_RAMP_HW
+	/* Set input voltage regulation reference voltage for charge ramp */
+	reg &= ~ISL9237_C0_VREG_REF_MASK;
+	reg |= ISL9237_C0_VREG_REF_4200;
+#else
+	/* Disable voltage regulation loop to disable charge ramp */
+	reg |= ISL9237_C0_DISABLE_VREG;
+#endif
+
+	return charger_set_option(reg);
 }
 
 int charger_discharge_on_ac(int enable)
@@ -245,6 +260,50 @@ int charger_discharge_on_ac(int enable)
 	return raw_write16(ISL9237_REG_CONTROL1, control1);
 }
 
+/*****************************************************************************/
+/* Hardware current ramping */
+
+#ifdef CONFIG_CHARGE_RAMP_HW
+int charger_set_hw_ramp(int enable)
+{
+	int rv, reg;
+
+	rv = charger_get_option(&reg);
+	if (rv)
+		return rv;
+
+	/* HW ramp is controlled by input voltage regulation reference bits */
+	if (enable)
+		reg &= ~ISL9237_C0_DISABLE_VREG;
+	else
+		reg |= ISL9237_C0_DISABLE_VREG;
+
+	return charger_set_option(reg);
+}
+
+int chg_ramp_is_stable(void)
+{
+	/*
+	 * Since ISL cannot read the current limit that the ramp has settled
+	 * on, then we can never consider the ramp stable, because we never
+	 * know what the stable limit is.
+	 */
+	return 0;
+}
+
+int chg_ramp_is_detected(void)
+{
+	return 1;
+}
+
+int chg_ramp_get_current_limit(void)
+{
+	/* ISL doesn't have a way to get this info */
+	return 0;
+}
+#endif /* CONFIG_CHARGE_RAMP_HW */
+
+
 #ifdef CONFIG_CHARGER_PSYS
 static void charger_enable_psys(void)
 {