diff options
Diffstat (limited to 'board/casta/board.c')
| -rw-r--r-- | board/casta/board.c | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/board/casta/board.c b/board/casta/board.c index 124601fa75..bcea197537 100644 --- a/board/casta/board.c +++ b/board/casta/board.c @@ -88,6 +88,49 @@ const struct temp_sensor_t temp_sensors[] = { }; BUILD_ASSERT(ARRAY_SIZE(temp_sensors) == TEMP_SENSOR_COUNT); +/* + * I2C callbacks to ensure bus free time for battery I2C transactions is at + * least 5ms. + */ +#define BATTERY_FREE_MIN_DELTA_US (5 * MSEC) +static timestamp_t battery_last_i2c_time; + +static int is_battery_i2c(int port, int slave_addr) +{ + return (port == I2C_PORT_BATTERY) && (slave_addr == BATTERY_ADDR); +} + +static int is_battery_port(int port) +{ + return (port == I2C_PORT_BATTERY); +} + +void i2c_start_xfer_notify(int port, int slave_addr) +{ + unsigned int time_delta_us; + + if (!is_battery_i2c(port, slave_addr)) + return; + + time_delta_us = time_since32(battery_last_i2c_time); + if (time_delta_us >= BATTERY_FREE_MIN_DELTA_US) + return; + + usleep(BATTERY_FREE_MIN_DELTA_US - time_delta_us); +} + +void i2c_end_xfer_notify(int port, int slave_addr) +{ + /* + * The bus free time needs to be maintained from last transaction + * on I2C bus to any device on it to the next transaction to battery. + */ + if (!is_battery_port(port)) + return; + + battery_last_i2c_time = get_time(); +} + void board_overcurrent_event(int port, int is_overcurrented) { /* Sanity check the port. */ |