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Diffstat (limited to 'firmware/microblaze/lib/i2c.c')
-rw-r--r--firmware/microblaze/lib/i2c.c177
1 files changed, 2 insertions, 175 deletions
diff --git a/firmware/microblaze/lib/i2c.c b/firmware/microblaze/lib/i2c.c
index 177341267..d230f462c 100644
--- a/firmware/microblaze/lib/i2c.c
+++ b/firmware/microblaze/lib/i2c.c
@@ -20,7 +20,6 @@
#include "memory_map.h"
#include "stdint.h"
#include <string.h>
-#include "pic.h"
#include "nonstdio.h"
#define MAX_WB_DIV 4 // maximum wishbone divisor (from 100 MHz MASTER_CLK)
@@ -37,18 +36,6 @@ static uint16_t prescaler_values[MAX_WB_DIV+1] = {
PRESCALER(4), // 4: 25 MHz
};
-//asynchronous (interrupt-driven) i2c state variables
-volatile uint8_t i2c_buf[17]; //tx/rx data transfer buffer
-volatile uint8_t *volatile i2c_bufptr = i2c_buf; //ptr to current position
-volatile uint8_t i2c_len = 0; //length remaining in current transfer
-volatile i2c_state_t i2c_state = I2C_STATE_IDLE; //current I2C transfer state
-i2c_dir_t i2c_dir; //I2C transfer direction
-
-void (*volatile i2c_callback)(void); //function pointer to i2c callback to be called when transaction is complete
-
-static void i2c_irq_handler(unsigned irq);
-inline void i2c_async_err(void);
-
void
i2c_init(void)
{
@@ -64,8 +51,8 @@ i2c_init(void)
i2c_regs->ctrl = I2C_CTRL_EN; //| I2C_CTRL_IE; // enable core
- // FIXME interrupt driven?
- pic_register_handler(IRQ_I2C, i2c_irq_handler);
+ //now this is done separately to maintain common code for async and sync
+ //pic_register_handler(IRQ_I2C, i2c_irq_handler);
}
static inline void
@@ -140,163 +127,3 @@ i2c_write(unsigned char i2c_addr, const unsigned char *buf, unsigned int len)
return false;
}
-static void i2c_irq_handler(unsigned irq) {
-//i2c state machine.
-
- //printf("I2C irq handler\n");
- //first let's make sure nothing is f'ed up
- //TODO: uncomment this error checking when we have some way to handle errors
-// if(((i2c_regs->cmd_status & I2C_ST_RXACK) != 0) && i2c_dir == I2C_DIR_WRITE) { //we got a NACK and we didn't send it
-// printf("\tNACK received\n");
-// i2c_async_err();
-// return;
-// }// else printf("\tACK received, proceeding\n");
-
- if(i2c_regs->cmd_status & I2C_ST_AL) {
- printf("\tArbitration lost!\n");
- i2c_async_err();
- return;
- }
-
- if(i2c_regs->cmd_status & I2C_ST_TIP) {
- //printf("\tI2C still busy in interrupt\n");
- return;
- }
-
- //now decide what to do
- switch(i2c_state) {
-
- case I2C_STATE_IDLE:
- //this is an error. in idle state, we shouldn't be transferring data, and the fact that the IRQ fired is terrible bad.
- printf("AAAAAHHHHH INTERRUPT IN THE IDLE STATE AAAHHHHHHHHH\n");
- i2c_async_err();
- break;
-
- case I2C_STATE_CONTROL_BYTE_SENT: //here we've sent the control byte, and we're either clocking data in or out now, but we haven't received a byte yet.
- case I2C_STATE_DATA: //here we're sending/receiving data and if we're receiving there's data in the data reg
-
- //if(i2c_state == I2C_STATE_DATA) printf("\tI2C in state DATA with dir=%d and len=%d\n", i2c_dir, i2c_len);
- //else printf("\tI2C in state CONTROL_BYTE_SENT with dir=%d and len=%d\n", i2c_dir, i2c_len);
-
- if(i2c_dir == I2C_DIR_READ) {
- if(i2c_state == I2C_STATE_DATA) *(i2c_bufptr++) = i2c_regs->data;
- //printf("\tRead %x\n", *(i2c_bufptr-1));
- //set up another data byte
- if(i2c_len > 1) //only one more byte to transfer
- i2c_regs->cmd_status = I2C_CMD_RD;
- else
- i2c_regs->cmd_status = I2C_CMD_RD | I2C_CMD_NACK | I2C_CMD_STOP;
- }
- else if(i2c_dir == I2C_DIR_WRITE) {
- //write a byte
- //printf("\tWriting %x\n", *i2c_bufptr);
- i2c_regs->data = *(i2c_bufptr++);
- if(i2c_len > 1)
- i2c_regs->cmd_status = I2C_CMD_WR;
- else {
- //printf("\tGenerating STOP\n");
- i2c_regs->cmd_status = I2C_CMD_WR | I2C_CMD_STOP;
- }
- };
- i2c_len--;
- if(i2c_len == 0) i2c_state = I2C_STATE_LAST_BYTE;
- else i2c_state = I2C_STATE_DATA; //takes care of the addr_sent->data transition
- break;
-
-
- case I2C_STATE_LAST_BYTE: //here we've already sent the last read request and the last data is waiting for us.
- //printf("\tI2C in state LAST BYTE\n");
-
- if(i2c_dir == I2C_DIR_READ) {
- *(i2c_bufptr++) = i2c_regs->data;
- //printf("\tRead %x\n", *(i2c_bufptr-1));
- i2c_state = I2C_STATE_DATA_READY;
- } else {
- i2c_state = I2C_STATE_IDLE;
- }
- i2c_regs->ctrl &= ~I2C_CTRL_IE; //disable interrupts until next time
-
- if(i2c_callback) {
- i2c_callback(); //if we registered a callback, call it!
- }
-
- break;
-
-
- default: //terrible things have happened.
- break;
- }
-
-}
-
-void i2c_register_callback(void (*volatile callback)(void)) {
- i2c_callback = callback;
-}
-
-inline void i2c_async_err(void) {
- i2c_state = I2C_STATE_IDLE;
- i2c_regs->ctrl &= ~I2C_CTRL_IE;
- printf("I2C error\n");
-//TODO: set an error flag instead of just dropping things on the floor
- i2c_regs->cmd_status = I2C_CMD_STOP;
-}
-
-bool i2c_async_read(uint8_t addr, unsigned int len) {
- //printf("Starting async read\n");
- if(i2c_state != I2C_STATE_IDLE) return false; //sorry mario but your i2c is in another castle
- if(len == 0) return true; //just idiot-proofing
- if(len > sizeof(i2c_buf)) return false;
-
- //disable I2C interrupts and clear pending interrupts on the I2C device
- i2c_regs->ctrl &= ~I2C_CTRL_IE;
- i2c_regs->cmd_status |= I2C_CMD_IACK;
-
- i2c_len = len;
- i2c_dir = I2C_DIR_READ;
- i2c_bufptr = i2c_buf;
- //then set up the transfer by issuing the control byte
- i2c_regs->ctrl |= I2C_CTRL_IE;
- i2c_regs->data = (addr << 1) | 0x01; //7 bit addr and read bit
- i2c_regs->cmd_status = I2C_CMD_WR | I2C_CMD_START; //generate start & start writing addr
- //update the state so the irq handler knows what's going on
- i2c_state = I2C_STATE_CONTROL_BYTE_SENT;
- return true;
-}
-
-bool i2c_async_write(uint8_t addr, const uint8_t *buf, unsigned int len) {
- //printf("Starting async write\n");
- if(i2c_state != I2C_STATE_IDLE) return false; //sorry mario but your i2c is in another castle
- if(len > sizeof(i2c_buf)) return false;
-
- //disable I2C interrupts and clear pending interrupts on the I2C device
- i2c_regs->ctrl &= ~I2C_CTRL_IE;
- i2c_regs->cmd_status |= I2C_CMD_IACK;
-
- //copy the buffer into our own if writing
- memcpy((void *)i2c_buf, buf, len);
-
- i2c_len = len;
- i2c_dir = I2C_DIR_WRITE;
- i2c_bufptr = i2c_buf;
- //then set up the transfer by issuing the control byte
- i2c_regs->ctrl |= I2C_CTRL_IE;
- i2c_regs->data = (addr << 1) | 0x00; //7 bit addr and read bit
- i2c_regs->cmd_status = I2C_CMD_WR | I2C_CMD_START; //generate start & start writing addr
- //update the state so the irq handler knows what's going on
- i2c_state = I2C_STATE_CONTROL_BYTE_SENT;
-
- return true;
-}
-
-//TODO: determine if it's better to read sequentially into the user's buffer, copy on transfer complete, or copy on request (shown below). probably best to copy on request.
-bool i2c_async_data_ready(void *buf) {
- if(i2c_state == I2C_STATE_DATA_READY) {
- i2c_state = I2C_STATE_IDLE;
- memcpy(buf, (void *)i2c_buf, (i2c_bufptr - i2c_buf)); //TODO: not really comfortable with this
- //printf("Copying %d bytes to user buffer\n", i2c_bufptr-i2c_buf);
- return true;
- }
- return false;
-}
-
-