mfd: cros_ec: Add API for EC-EC communication

Allow EC to talk to other ECs that are not presented to the host.
Neeed when EC are present in detachable keyboard.

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Acked-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Acked-by: Benson Leung <bleung@chromium.org>
Reviewed-by: Fabien Lahoudere <fabien.lahoudere@collabora.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

include/linux/mfd/cros_ec_commands.h

@@ -5043,6 +5043,101 @@ struct ec_response_pd_chip_info_v1 {
 	};
 } __ec_align2;
 
+/*****************************************************************************/
+/* EC-EC communication commands: range 0x0600-0x06FF */
+
+#define EC_COMM_TEXT_MAX 8
+
+/*
+ * Get battery static information, i.e. information that never changes, or
+ * very infrequently.
+ */
+#define EC_CMD_BATTERY_GET_STATIC 0x0600
+
+/**
+ * struct ec_params_battery_static_info - Battery static info parameters
+ * @index: Battery index.
+ */
+struct ec_params_battery_static_info {
+	uint8_t index;
+} __ec_align_size1;
+
+/**
+ * struct ec_response_battery_static_info - Battery static info response
+ * @design_capacity: Battery Design Capacity (mAh)
+ * @design_voltage: Battery Design Voltage (mV)
+ * @manufacturer: Battery Manufacturer String
+ * @model: Battery Model Number String
+ * @serial: Battery Serial Number String
+ * @type: Battery Type String
+ * @cycle_count: Battery Cycle Count
+ */
+struct ec_response_battery_static_info {
+	uint16_t design_capacity;
+	uint16_t design_voltage;
+	char manufacturer[EC_COMM_TEXT_MAX];
+	char model[EC_COMM_TEXT_MAX];
+	char serial[EC_COMM_TEXT_MAX];
+	char type[EC_COMM_TEXT_MAX];
+	/* TODO(crbug.com/795991): Consider moving to dynamic structure. */
+	uint32_t cycle_count;
+} __ec_align4;
+
+/*
+ * Get battery dynamic information, i.e. information that is likely to change
+ * every time it is read.
+ */
+#define EC_CMD_BATTERY_GET_DYNAMIC 0x0601
+
+/**
+ * struct ec_params_battery_dynamic_info - Battery dynamic info parameters
+ * @index: Battery index.
+ */
+struct ec_params_battery_dynamic_info {
+	uint8_t index;
+} __ec_align_size1;
+
+/**
+ * struct ec_response_battery_dynamic_info - Battery dynamic info response
+ * @actual_voltage: Battery voltage (mV)
+ * @actual_current: Battery current (mA); negative=discharging
+ * @remaining_capacity: Remaining capacity (mAh)
+ * @full_capacity: Capacity (mAh, might change occasionally)
+ * @flags: Flags, see EC_BATT_FLAG_*
+ * @desired_voltage: Charging voltage desired by battery (mV)
+ * @desired_current: Charging current desired by battery (mA)
+ */
+struct ec_response_battery_dynamic_info {
+	int16_t actual_voltage;
+	int16_t actual_current;
+	int16_t remaining_capacity;
+	int16_t full_capacity;
+	int16_t flags;
+	int16_t desired_voltage;
+	int16_t desired_current;
+} __ec_align2;
+
+/*
+ * Control charger chip. Used to control charger chip on the slave.
+ */
+#define EC_CMD_CHARGER_CONTROL 0x0602
+
+/**
+ * struct ec_params_charger_control - Charger control parameters
+ * @max_current: Charger current (mA). Positive to allow base to draw up to
+ *     max_current and (possibly) charge battery, negative to request current
+ *     from base (OTG).
+ * @otg_voltage: Voltage (mV) to use in OTG mode, ignored if max_current is
+ *     >= 0.
+ * @allow_charging: Allow base battery charging (only makes sense if
+ *     max_current > 0).
+ */
+struct ec_params_charger_control {
+	int16_t max_current;
+	uint16_t otg_voltage;
+	uint8_t allow_charging;
+} __ec_align_size1;
+
 /*****************************************************************************/
 /*
  * Reserve a range of host commands for board-specific, experimental, or