URL
https://opencores.org/ocsvn/minsoc/minsoc/trunk
Subversion Repositories minsoc
[/] [minsoc/] [branches/] [rc-1.0/] [sw/] [drivers/] [i2c.c] - Rev 169
Go to most recent revision | Compare with Previous | Blame | View Log
#include <board.h> #include <support.h> #include "i2c.h" int i2c_rd_done, i2c_wr_done; int i2c_pending_write; int i2c_rd_ptr, i2c_wr_ptr; int i2c_buf_overflow; i2c_type i2c_data[I2C_BUF_LEN]; unsigned char start, pointer_write, write_hbyte, write_lbyte, read_hbyte, read_lbyte; unsigned char cmd_list[5]; unsigned char dat_list[5]; int i2c_index; int i2c_end; i2c_type * i2c_get(void) { if ( !i2c_rd_done ) return NULL; i2c_rd_done--; int tmp; tmp = i2c_rd_ptr; if (i2c_rd_ptr < I2C_BUF_LEN-1) i2c_rd_ptr++; else i2c_rd_ptr = 0; return &i2c_data[tmp]; } void i2c_init(void) { REG8(I2C_BASE+I2C_PRESC_HI) = 0x00; REG8(I2C_BASE+I2C_PRESC_LO) = 49; //100kHz REG8(I2C_BASE+I2C_CTR) = I2C_CTR_EN | I2C_CTR_IRQ_EN; i2c_rd_done = 0; i2c_wr_done = 0; i2c_index = 0; i2c_wr_ptr = 0; i2c_rd_ptr = 0; i2c_buf_overflow = 0; } void i2c_set_ack_lvl(int ack_lvl, int final_ack_lvl) { int ack, final_ack; ack = ( ack_lvl ) ? I2C_CR_NACK : I2C_CR_ACK; final_ack = ( final_ack_lvl ) ? I2C_CR_NACK : I2C_CR_ACK; start = I2C_CR_STA | I2C_CR_WR | ack; pointer_write = I2C_CR_WR | ack; write_hbyte = I2C_CR_WR | ack; write_lbyte = I2C_CR_WR | I2C_CR_STO | final_ack; read_hbyte = I2C_CR_RD | ack; read_lbyte = I2C_CR_RD | I2C_CR_STO | final_ack; } void i2c_byte_transfer(void) { if ( i2c_index > 0 ) if ( cmd_list[i2c_index-1] == read_hbyte ) i2c_data[i2c_wr_ptr].data = (REG8(I2C_BASE+I2C_RXR) << 8) & 0xFF00; REG8(I2C_BASE+I2C_TXR) = dat_list[i2c_index]; REG8(I2C_BASE+I2C_CR) = cmd_list[i2c_index]; i2c_index++; } void i2c_irq(void) { REG8(I2C_BASE+I2C_CR) = I2C_CR_CLR_IRQ; if (i2c_index <= i2c_end ) i2c_byte_transfer(); else { if ( cmd_list[i2c_index-1] == read_lbyte ) i2c_data[i2c_wr_ptr].data |= REG8(I2C_BASE+I2C_RXR); i2c_index = 0; if ( i2c_pending_write ) i2c_wr_done = 1; else { if (i2c_wr_ptr < I2C_BUF_LEN-1) i2c_wr_ptr++; else i2c_wr_ptr = 0; if (i2c_wr_ptr == i2c_rd_ptr+1) { i2c_rd_done = 1; i2c_buf_overflow++; } else i2c_rd_done++; } } } int i2c_trans(i2c_mode * mode, i2c_type * data) { if ( i2c_index != 0 ) //if previous command not fully processed, bail out return -1; i2c_wr_done = 0; int i = 0; if ( mode->ptr_set || mode->read_write ) //start conditions with pointer set: (write always set ptr) { dat_list[i] = (data->address << 1) & I2C_TXR_ADR; dat_list[i] |= I2C_TXR_W; cmd_list[i++] = start; dat_list[i] = data->pointer; cmd_list[i++] = pointer_write; if ( !mode->read_write ) //REstart for read, NO-REstart for write { dat_list[i] = (data->address << 1) & I2C_TXR_ADR; dat_list[i] |= I2C_TXR_R; cmd_list[i++] = start; } } else //start conditions with NO pointer set (read only): ONE start { dat_list[i] = (data->address << 1) & I2C_TXR_ADR; dat_list[i] |= I2C_TXR_R; cmd_list[i++] = start; } if ( mode->byte_word ) //read/write high byte { dat_list[i] = data->data >> 8; cmd_list[i++] = (mode->read_write) ? write_hbyte : read_hbyte; } dat_list[i] = data->data; //read/write low byte cmd_list[i] = (mode->read_write) ? write_lbyte : read_lbyte; i2c_end = i; if ( !mode->read_write ) //set data to 0 for read, avoid or implications ((short)data |= byte) { i2c_data[i2c_wr_ptr] = *data; i2c_data[i2c_wr_ptr].data = 0x0000; } i2c_pending_write = mode->read_write; i2c_index = 0; i2c_byte_transfer(); return mode->read_write+1; }
Go to most recent revision | Compare with Previous | Blame | View Log