2018-12-12 11:20:27 +01:00

148 lines
6.6 KiB
C
Executable File

#pragma once
#include "blackfin.h"
/**
* To be defined
*
* (in blackfin.h)
* I2C_CLOCK_MHZ
*
* (RegisterDefs.h)
* I2C_SCL_LOW_COUNT_REG
* I2C_SCL_HIGH_COUNT_REG
* I2C_SDA_HOLD_REG
* I2C_CONTROL_REG
* I2C_TRANSFER_COMMAND_FIFO_REG
* I2C_RX_DATA_FIFO_LEVEL_REG
*/
#define I2C_DATA_RATE_KBPS (200)
#define I2C_SCL_PERIOD_NS ((1000 * 1000) / I2C_DATA_RATE_KBPS)
#define I2C_SCL_LOW_PERIOD_NS (I2C_SCL_PERIOD_NS / 2)
#define I2C_SDA_DATA_HOLD_TIME_NS (I2C_SCL_HIGH_PERIOD_NS / 2)
#define I2C_SCL_LOW_COUNT ((I2C_SCL_LOW_PERIOD_NS / 1000) * I2C_CLOCK_MHZ) // convert to us, then to clock (defined in blackfin.h)
#define I2C_SDA_DATA_HOLD_COUNT ((I2C_SDA_DATA_HOLD_TIME_NS / 1000) * I2C_CLOCK_MHZ) // convert to us, then to clock (defined in blackfin.h)
/** Control Register */
#define I2C_CTRL_ENBLE_CORE_OFST (0)
#define I2C_CTRL_ENBLE_CORE_MSK (0x00000001 << I2C_CTRL_ENBLE_CORE_OFST)
#define I2C_CTRL_BUS_SPEED_OFST (1)
#define I2C_CTRL_BUS_SPEED_MSK (0x00000001 << I2C_CTRL_BUS_SPEED_OFST)
#define I2C_CTRL_BUS_SPEED_STNDRD_100_VAL ((0x0 << I2C_CTRL_BUS_SPEED_OFST) & I2C_CTRL_BUS_SPEED_MSK) // standard mode (up to 100 kbps)
#define I2C_CTRL_BUS_SPEED_FAST_400_VAL ((0x1 << I2C_CTRL_BUS_SPEED_OFST) & I2C_CTRL_BUS_SPEED_MSK) // fast mode (up to 400 kbps)
/** if actual level of transfer command fifo <= thd level, TX_READY interrupt asserted */
#define I2C_CTRL_TFR_CMD_FIFO_THD_OFST (2)
#define I2C_CTRL_TFR_CMD_FIFO_THD_MSK (0x00000003 << I2C_CTRL_TFR_CMD_FIFO_THD_OFST)
#define I2C_CTRL_TFR_CMD_EMPTY_VAL ((0x0 << I2C_CTRL_TFR_CMD_FIFO_THD_OFST) & I2C_CTRL_TFR_CMD_FIFO_THD_MSK)
#define I2C_CTRL_TFR_CMD_ONE_FOURTH_VAL ((0x1 << I2C_CTRL_TFR_CMD_FIFO_THD_OFST) & I2C_CTRL_TFR_CMD_FIFO_THD_MSK)
#define I2C_CTRL_TFR_CMD_ONE_HALF_VAL ((0x2 << I2C_CTRL_TFR_CMD_FIFO_THD_OFST) & I2C_CTRL_TFR_CMD_FIFO_THD_MSK)
#define I2C_CTRL_TFR_CMD_NOT_FULL_VAL ((0x3 << I2C_CTRL_TFR_CMD_FIFO_THD_OFST) & I2C_CTRL_TFR_CMD_FIFO_THD_MSK)
/** if actual level of receive data fifo <= thd level, RX_READY interrupt asserted */
#define I2C_CTRL_RX_DATA_FIFO_THD_OFST (4)
#define I2C_CTRL_RX_DATA_FIFO_THD_MSK (0x00000003 << I2C_CTRL_RX_DATA_FIFO_THD_OFST)
#define I2C_CTRL_RX_DATA_1_VALID_ENTRY_VAL ((0x0 << I2C_CTRL_RX_DATA_FIFO_THD_OFST) & I2C_CTRL_RX_DATA_FIFO_THD_MSK)
#define I2C_CTRL_RX_DATA_ONE_FOURTH_VAL ((0x1 << I2C_CTRL_RX_DATA_FIFO_THD_OFST) & I2C_CTRL_RX_DATA_FIFO_THD_MSK)
#define I2C_CTRL_RX_DATA_ONE_HALF_VAL ((0x2 << I2C_CTRL_RX_DATA_FIFO_THD_OFST) & I2C_CTRL_RX_DATA_FIFO_THD_MSK)
#define I2C_CTRL_RX_DATA_FULL_VAL ((0x3 << I2C_CTRL_RX_DATA_FIFO_THD_OFST) & I2C_CTRL_RX_DATA_FIFO_THD_MSK)
/** Transfer Command Fifo register */
#define I2C_TFR_CMD_RW_OFST (0)
#define I2C_TFR_CMD_RW_MSK (0x00000001 << I2C_TFR_CMD_RW_OFST)
#define I2C_TFR_CMD_RW_WRITE_VAL ((0x0 << I2C_TFR_CMD_RW_OFST) & I2C_TFR_CMD_RW_MSK)
#define I2C_TFR_CMD_RW_READ_VAL ((0x1 << I2C_TFR_CMD_RW_OFST) & I2C_TFR_CMD_RW_MSK)
#define I2C_TFR_CMD_ADDR_OFST (1)
#define I2C_TFR_CMD_ADDR_MSK (0x0000007F << I2C_TFR_CMD_ADDR_OFST)
/** when writing, rw and addr converts to data to be written mask */
#define I2C_TFR_CMD_DATA_FR_WR_OFST (0)
#define I2C_TFR_CMD_DATA_FR_WR_MSK (0x000000FF << I2C_TFR_CMD_DATA_FR_WR_OFST)
#define I2C_TFR_CMD_STOP_OFST (8)
#define I2C_TFR_CMD_STOP_MSK (0x00000001 << I2C_TFR_CMD_ADDR_OFST)
#define I2C_TFR_CMD_RPTD_STRT_OFST (9)
#define I2C_TFR_CMD_RPTD_STRT_MSK (0x00000001 << I2C_TFR_CMD_RPTD_STRT_OFST)
/**
* Configure the I2C core,
* Enable core and
* Calibrate the calibration register for current readout
*/
void I2C_ConfigureI2CCore() {
FILE_LOG(logINFOBLUE, ("\tConfiguring I2C Core for %d kbps:\n", I2C_DATA_RATE_KBPS));
FILE_LOG(logINFOBLUE, ("\tSetting SCL Low Period: %d ns (0x%x clocks)\n", I2C_SCL_LOW_PERIOD_NS, I2C_SCL_LOW_COUNT));
bus_w(I2C_SCL_LOW_COUNT_REG, (uint32_t)I2C_SCL_LOW_COUNT);
FILE_LOG(logINFOBLUE, ("\tSetting SCL High Period: %d ns (0x%x clocks)\n", I2C_SCL_HIGH_PERIOD_NS, I2C_SCL_LOW_COUNT));
bus_w(I2C_SCL_HIGH_COUNT_REG, (uint32_t)I2C_SCL_LOW_COUNT);
FILE_LOG(logINFOBLUE, ("\tSetting SDA Hold Time: %d ns (0x%x clocks)\n", I2C_SDA_DATA_HOLD_TIME_NS, I2C_SDA_DATA_HOLD_COUNT));
bus_w(I2C_SDA_HOLD_REG, (uint32_t)I2C_SDA_DATA_HOLD_COUNT);
FILE_LOG(logINFOBLUE, ("\tEnabling core\n"));
bus_w(I2C_CONTROL_REG, I2C_CTRL_ENBLE_CORE_MSK | I2C_CTRL_BUS_SPEED_FAST_400_VAL);// fixme: (works?)
}
/**
* Read register
* @param deviceId device Id
* @param addr register address
* @returns value read from register
*/
uint32_t I2C_Read(uint32_t devId, uint32_t addr) {
FILE_LOG(logDEBUG1, ("\tReading from I2C device 0x%x and reg 0x%x\n", devId, addr));
// device Id mask
uint32_t devIdMask = ((devId << I2C_TFR_CMD_ADDR_OFST) & I2C_TFR_CMD_ADDR_MSK);
// write I2C ID
bus_w(I2C_TRANSFER_COMMAND_FIFO_REG, (devIdMask & ~(I2C_TFR_CMD_RW_MSK)));
// write register addr
bus_w(I2C_TRANSFER_COMMAND_FIFO_REG, addr);
// repeated start with read
bus_w(I2C_TRANSFER_COMMAND_FIFO_REG, (devIdMask | I2C_TFR_CMD_RPTD_STRT_MSK | I2C_TFR_CMD_RW_READ_VAL));
// continue reading
bus_w(I2C_TRANSFER_COMMAND_FIFO_REG, 0x0);
// stop reading
bus_w(I2C_TRANSFER_COMMAND_FIFO_REG, I2C_TFR_CMD_STOP_MSK);
// read value
return bus_r(I2C_RX_DATA_FIFO_LEVEL_REG);
}
/**
* Write register (16 bit value)
* @param deviceId device Id
* @param addr register address
* @param data data to be written (16 bit)
*/
void I2C_Write(uint32_t devId, uint32_t addr, uint16_t data) {
FILE_LOG(logDEBUG1, ("\tWriting data %d to I2C device 0x%x and reg 0x%x\n", data, devId, addr));
// device Id mask
uint32_t devIdMask = ((devId << I2C_TFR_CMD_ADDR_OFST) & I2C_TFR_CMD_ADDR_MSK);
// write I2C ID
bus_w(I2C_TRANSFER_COMMAND_FIFO_REG, (devIdMask & ~(I2C_TFR_CMD_RW_MSK)));
// write register addr
bus_w(I2C_TRANSFER_COMMAND_FIFO_REG, addr);
// repeated start with write
bus_w(I2C_TRANSFER_COMMAND_FIFO_REG, (devIdMask | I2C_TFR_CMD_RPTD_STRT_MSK & ~(I2C_TFR_CMD_RW_MSK)));
uint8_t msb = data & 0xFF00;
uint8_t lsb = data & 0x00FF;
// writing data MSB
bus_w(I2C_TRANSFER_COMMAND_FIFO_REG, ((msb << I2C_TFR_CMD_DATA_FR_WR_OFST) & I2C_TFR_CMD_DATA_FR_WR_MSK));
// writing data LSB and stop writing bit
bus_w(I2C_TRANSFER_COMMAND_FIFO_REG, ((lsb << I2C_TFR_CMD_DATA_FR_WR_OFST) & I2C_TFR_CMD_DATA_FR_WR_MSK) | I2C_TFR_CMD_STOP_MSK);
}