U2P: Bootloader works, successfully loads production image.

Split I2C into async and sync halves to keep the size of the bootloader small.

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;
-}
-
-