lucid: implement fast charging

Use custom charging profile to enable charging at a faster rate.

BUG=chrome-os-partner:48662
BRANCH=none
TEST=load on lucid and charge at room temp. Use "chgstate" command to
verify that battery current matches the expected fast charging current
for the given temp range and voltage.

Change-Id: Ie508d29db091593ff2cfda9d135c73f6a3de5a9a
Signed-off-by: Mary Ruthven <mruthven@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/319493
Commit-Ready: Alec Berg <alecaberg@chromium.org>
Tested-by: Alec Berg <alecaberg@chromium.org>
Reviewed-by: Alec Berg <alecaberg@chromium.org>

2 files changed, 150 insertions, 0 deletions

diff --git a/board/lucid/battery.c b/board/lucid/battery.c
index 7d1cc7fadd..7dc3872dff 100644
--- a/board/lucid/battery.c
+++ b/board/lucid/battery.c
@@ -7,6 +7,9 @@
 
 #include "battery.h"
 #include "battery_smart.h"
+#include "charge_state.h"
+#include "console.h"
+#include "ec_commands.h"
 #include "i2c.h"
 #include "util.h"
 
@@ -52,3 +55,149 @@ int board_cut_off_battery(void)
 
 	return rv;
 }
+
+#ifdef CONFIG_CHARGER_PROFILE_OVERRIDE
+
+static int fast_charging_allowed = 1;
+
+/*
+ * This can override the smart battery's charging profile. To make a change,
+ * modify one or more of requested_voltage, requested_current, or state.
+ * Leave everything else unchanged.
+ *
+ * Return the next poll period in usec, or zero to use the default (which is
+ * state dependent).
+ */
+int charger_profile_override(struct charge_state_data *curr)
+{
+	/* temp in 0.1 deg C */
+	int temp_c = curr->batt.temperature - 2731;
+	/* keep track of last temperature range for hysteresis */
+	static enum {
+		TEMP_LOW,
+		TEMP_NORMAL,
+		TEMP_HIGH,
+	} temp_range = TEMP_NORMAL;
+	/* keep track of last voltage range for hysteresis */
+	static enum {
+		VOLTAGE_RANGE_LOW,
+		VOLTAGE_RANGE_HIGH,
+	} voltage_range = VOLTAGE_RANGE_LOW;
+
+	/* Current and previous battery voltage */
+	int batt_voltage;
+	static int prev_batt_voltage;
+
+	/*
+	 * Determine temperature range. The five ranges are:
+	 *   < 15C
+	 *   15-45C
+	 *   > 45C
+	 *
+	 * Add 0.2 degrees of hysteresis.
+	 * If temp reading was bad, use last range.
+	 */
+	if (!(curr->batt.flags & BATT_FLAG_BAD_TEMPERATURE)) {
+		if (temp_c < 149)
+			temp_range = TEMP_LOW;
+		else if (temp_c > 151 && temp_c < 449)
+			temp_range = TEMP_NORMAL;
+		else if (temp_c > 451)
+			temp_range = TEMP_HIGH;
+	}
+
+	/*
+	 * If battery voltage reading is bad, use the last reading. Otherwise,
+	 * determine voltage range with hysteresis.
+	 */
+	if (curr->batt.flags & BATT_FLAG_BAD_VOLTAGE) {
+		batt_voltage = prev_batt_voltage;
+	} else {
+		batt_voltage = prev_batt_voltage = curr->batt.voltage;
+		if (batt_voltage < 4050)
+			voltage_range = VOLTAGE_RANGE_LOW;
+		else if (batt_voltage > 4150)
+			voltage_range = VOLTAGE_RANGE_HIGH;
+	}
+
+	/*
+	 * If we are not charging or we aren't using fast charging profiles,
+	 * then do not override desired current and voltage.
+	 */
+	if (curr->state != ST_CHARGE || !fast_charging_allowed)
+		return 0;
+
+	/*
+	 * Okay, impose our custom will:
+	 * When battery is 0-15C:
+	 * CC at 1.8A @ 4.35V
+	 * CV at 4.35V
+	 *
+	 * When battery is <45C:
+	 * CC at 6A until 4.15V @ 4.35V
+	 * CC at 3A @ 4.35V
+	 * CV at 4.35V until current drops to 3A
+	 *
+	 * When battery is >45C:
+	 * CC at 4.2A @ 4.1V
+	 * CV at 4.1V (when battery is hot we don't go to fully charged)
+	 */
+	switch (temp_range) {
+	case TEMP_LOW:
+		curr->requested_current = 1800;
+		curr->requested_voltage = 4350;
+		break;
+	case TEMP_NORMAL:
+		curr->requested_voltage = 4350;
+		if (voltage_range == VOLTAGE_RANGE_LOW)
+			curr->requested_current = 6000;
+		else
+			curr->requested_current = 3000;
+		break;
+	case TEMP_HIGH:
+		curr->requested_current = 4200;
+		curr->requested_voltage = 4100;
+		break;
+	}
+
+	return 0;
+}
+
+/* Customs options controllable by host command. */
+#define PARAM_FASTCHARGE (CS_PARAM_CUSTOM_PROFILE_MIN + 0)
+
+enum ec_status charger_profile_override_get_param(uint32_t param,
+						  uint32_t *value)
+{
+	if (param == PARAM_FASTCHARGE) {
+		*value = fast_charging_allowed;
+		return EC_RES_SUCCESS;
+	}
+	return EC_RES_INVALID_PARAM;
+}
+
+enum ec_status charger_profile_override_set_param(uint32_t param,
+						  uint32_t value)
+{
+	if (param == PARAM_FASTCHARGE) {
+		fast_charging_allowed = value;
+		return EC_RES_SUCCESS;
+	}
+	return EC_RES_INVALID_PARAM;
+}
+
+static int command_fastcharge(int argc, char **argv)
+{
+	if (argc > 1 && !parse_bool(argv[1], &fast_charging_allowed))
+		return EC_ERROR_PARAM1;
+
+	ccprintf("fastcharge %s\n", fast_charging_allowed ? "on" : "off");
+
+	return EC_SUCCESS;
+}
+DECLARE_CONSOLE_COMMAND(fastcharge, command_fastcharge,
+			"[on|off]",
+			"Get or set fast charging profile",
+			NULL);
+
+#endif	/* CONFIG_CHARGER_PROFILE_OVERRIDE */
diff --git a/board/lucid/board.h b/board/lucid/board.h
index 5844e22250..e193f276f3 100644
--- a/board/lucid/board.h
+++ b/board/lucid/board.h
@@ -28,6 +28,7 @@
 #define CONFIG_CHARGER_BQ24773
 #define CONFIG_CHARGER_ILIM_PIN_DISABLED
 #define CONFIG_CHARGER_INPUT_CURRENT 500
+#define CONFIG_CHARGER_PROFILE_OVERRIDE
 #define CONFIG_CHARGER_SENSE_RESISTOR 5
 #define CONFIG_CHARGER_SENSE_RESISTOR_AC 10
 #undef  CONFIG_CMD_I2C_SCAN