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>

board/glados/board.c

@@ -321,6 +321,40 @@ void board_set_charge_limit(int charge_ma)
 					   CONFIG_CHARGER_INPUT_CURRENT));
 }
 
+/**
+ * Return whether ramping is allowed for given supplier
+ */
+int board_is_ramp_allowed(int supplier)
+{
+	/* Don't allow ramping in RO when write protected */
+	if (system_get_image_copy() != SYSTEM_IMAGE_RW
+	    && system_is_locked())
+		return 0;
+	else
+		return supplier == CHARGE_SUPPLIER_BC12_DCP ||
+		       supplier == CHARGE_SUPPLIER_BC12_SDP ||
+		       supplier == CHARGE_SUPPLIER_BC12_CDP ||
+		       supplier == CHARGE_SUPPLIER_PROPRIETARY;
+}
+
+/**
+ * Return the maximum allowed input current
+ */
+int board_get_ramp_current_limit(int supplier, int sup_curr)
+{
+	switch (supplier) {
+	case CHARGE_SUPPLIER_BC12_DCP:
+		return 2000;
+	case CHARGE_SUPPLIER_BC12_SDP:
+		return 1000;
+	case CHARGE_SUPPLIER_BC12_CDP:
+	case CHARGE_SUPPLIER_PROPRIETARY:
+		return sup_curr;
+	default:
+		return 500;
+	}
+}
+
 /* Enable or disable input devices, based upon chipset state and tablet mode */
 static void enable_input_devices(void)
 {

board/glados/board.h

@@ -20,6 +20,7 @@
 #define CONFIG_BOARD_VERSION
 #define CONFIG_BUTTON_COUNT 2
 #define CONFIG_CHARGE_MANAGER
+#define CONFIG_CHARGE_RAMP_HW
 
 #define CONFIG_CHARGER
 #define CONFIG_CHARGER_V2

common/charge_manager.c

@@ -7,6 +7,7 @@
 #include "battery.h"
 #include "charge_manager.h"
 #include "charge_ramp.h"
+#include "charger.h"
 #include "console.h"
 #include "gpio.h"
 #include "hooks.h"
@@ -511,6 +512,10 @@ static void charge_manager_refresh(void)
 				new_port, new_supplier, new_charge_current,
 				registration_time[new_port]);
 #else
+#ifdef CONFIG_CHARGE_RAMP_HW
+		/* Enable or disable charge ramp */
+		charger_set_hw_ramp(board_is_ramp_allowed(new_supplier));
+#endif
 		board_set_charge_limit(new_charge_current);
 #endif
 		CPRINTS("CL: p%d s%d i%d v%d", new_port, new_supplier,

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;

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 */

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)
 {

include/charger.h

@@ -111,6 +111,7 @@ int charger_manufacturer_id(int *id);
 int charger_device_id(int *id);
 int charger_get_option(int *option);
 int charger_set_option(int option);
+int charger_set_hw_ramp(int enable);
 
 /* Print all charger info for debugging purposes */
 void print_charger_debug(void);