common/i2c.h

   1
   2 #ifndef _TWI_I2C_H_
   3 #define _TWI_I2C_H_
   4
   5 #include <util/twi.h>
   6
   7 /** I2C Clock Generation **/
   8 #define F_SCL 100000
   9 #define TWI_PS_MSK 0
  10 #define TWI_BR_VAL -(16*F_SCL-F_CPU)/(2*F_SCL)
  11
  12 /** Slave Mode **/
  13 // Slave Address(s) for device  0b7654321
  14 #define I2C_SLAVE_ADDR          0b0011100
  15 #define I2C_SLAVE_ADDR_MSK      0b0000000
  16 // Respond to General Call in Slave mode?
  17 #define I2C_GENERAL_CALL_EN 0
  18
  19 /** State Control **/
  20 typedef enum {  I2C_IDLE = 0,
  21                 I2C_BUSY = 1,
  22                 I2C_MT = 2,
  23                 I2C_MR = 3,
  24                 I2C_ST = 4,
  25                 I2C_SR = 5
  26 } i2c_mode_t;
  27 i2c_mode_t i2c_mode;
  28
  29
  30 /** TWCR Control Values **/
  31 // Enabe TWI, Clear INT flag, Enable Ack, Enable Interupt
  32 #define TWCR_NACK       ( (1<<TWEN)|(1<<TWINT)|(1<<TWIE) )
  33 #define TWCR_BASE       ( TWCR_NACK|(1<<TWEA) )
  34 #define TWCR_START      ( TWCR_BASE|(1<<TWSTA) )
  35 #define TWCR_STOP       ( TWCR_BASE|(1<<TWSTO) )
  36 #define TWCR_RESET      ( TWCR_BASE|(1<<TWSTO)|(1<<TWSTA) )
  37
  38
  39 /** Transfer Control & Queue **/
  40 /*
  41 typedef struct {
  42         uint8_t addr;
  43         uint8_t w_len;
  44         uint8_t r_len;
  45         uint8_t * w_buf;
  46         uint8_t * r_buf;
  47         uint8_t w_pos;
  48         uint8_t r_pos;
  49         uint8_t (*callback)(void);
  50 } i2c_msg_t;
  51
  52 uint8_t i2c_msg_curr;
  53 uint8_t i2c_buf_loc;
  54
  55 #define I2C_MSG_BUF_LEN 5
  56 i2c_msg_t i2c_msg_buffer[I2C_MSG_BUF_LEN];
  57
  58 void i2c_next_msg();
  59
  60 int i2c_add_msg(uint8_t addr,
  61         uint8_t w_len,
  62         uint8_t r_len,
  63         uint8_t * w_buf,
  64         uint8_t * r_buf,
  65         uint8_t (*callback)(void);
  66 int i2c_rem_msg(int msg_num);
  67 */
  68
  69 /** Static Bus Operation **/
  70 uint8_t dev_w_addr;
  71 uint8_t dev_r_addr;
  72
  73 uint8_t w_data_buf_len;
  74 uint8_t * w_data_buf;
  75 volatile uint8_t w_data_buf_pos;
  76
  77 uint8_t r_data_buf_len;
  78 volatile uint8_t * r_data_buf;
  79 volatile uint8_t r_data_buf_pos;
  80
  81 uint8_t (*xfer_complete_cb)(void);
  82
  83
  84 /** Functions **/
  85 void twi_init(void);
  86 int i2c_reset_xfer(void);
  87 int i2c_start_xfer(void);
  88
  89
  90
  91 #endif