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mv64x60_i2c.c

/*
 * Bootloader version of the i2c driver for the MV64x60.
 *
 * Author: Dale Farnsworth <dfarnsworth@mvista.com>
 * Maintained by: Mark A. Greer <mgreer@mvista.com>
 *
 * 2003, 2007 (c) MontaVista, Software, Inc.  This file is licensed under
 * the terms of the GNU General Public License version 2.  This program is
 * licensed "as is" without any warranty of any kind, whether express or
 * implied.
 */

#include <stdarg.h>
#include <stddef.h>
#include "types.h"
#include "elf.h"
#include "page.h"
#include "string.h"
#include "stdio.h"
#include "io.h"
#include "ops.h"
#include "mv64x60.h"

/* Register defines */
#define MV64x60_I2C_REG_SLAVE_ADDR              0x00
#define MV64x60_I2C_REG_DATA                    0x04
#define MV64x60_I2C_REG_CONTROL                       0x08
#define MV64x60_I2C_REG_STATUS                        0x0c
#define MV64x60_I2C_REG_BAUD                    0x0c
#define MV64x60_I2C_REG_EXT_SLAVE_ADDR                0x10
#define MV64x60_I2C_REG_SOFT_RESET              0x1c

#define MV64x60_I2C_CONTROL_ACK                       0x04
#define MV64x60_I2C_CONTROL_IFLG                0x08
#define MV64x60_I2C_CONTROL_STOP                0x10
#define MV64x60_I2C_CONTROL_START               0x20
#define MV64x60_I2C_CONTROL_TWSIEN              0x40
#define MV64x60_I2C_CONTROL_INTEN               0x80

#define MV64x60_I2C_STATUS_BUS_ERR              0x00
#define MV64x60_I2C_STATUS_MAST_START                 0x08
#define MV64x60_I2C_STATUS_MAST_REPEAT_START          0x10
#define MV64x60_I2C_STATUS_MAST_WR_ADDR_ACK           0x18
#define MV64x60_I2C_STATUS_MAST_WR_ADDR_NO_ACK        0x20
#define MV64x60_I2C_STATUS_MAST_WR_ACK                0x28
#define MV64x60_I2C_STATUS_MAST_WR_NO_ACK       0x30
#define MV64x60_I2C_STATUS_MAST_LOST_ARB        0x38
#define MV64x60_I2C_STATUS_MAST_RD_ADDR_ACK           0x40
#define MV64x60_I2C_STATUS_MAST_RD_ADDR_NO_ACK        0x48
#define MV64x60_I2C_STATUS_MAST_RD_DATA_ACK           0x50
#define MV64x60_I2C_STATUS_MAST_RD_DATA_NO_ACK        0x58
#define MV64x60_I2C_STATUS_MAST_WR_ADDR_2_ACK         0xd0
#define MV64x60_I2C_STATUS_MAST_WR_ADDR_2_NO_ACK      0xd8
#define MV64x60_I2C_STATUS_MAST_RD_ADDR_2_ACK         0xe0
#define MV64x60_I2C_STATUS_MAST_RD_ADDR_2_NO_ACK      0xe8
#define MV64x60_I2C_STATUS_NO_STATUS                  0xf8

static u8 *ctlr_base;

static int mv64x60_i2c_wait_for_status(int wanted)
{
      int i;
      int status;

      for (i=0; i<1000; i++) {
            udelay(10);
            status = in_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_STATUS))
                  & 0xff;
            if (status == wanted)
                  return status;
      }
      return -status;
}

static int mv64x60_i2c_control(int control, int status)
{
      out_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_CONTROL), control & 0xff);
      return mv64x60_i2c_wait_for_status(status);
}

static int mv64x60_i2c_read_byte(int control, int status)
{
      out_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_CONTROL), control & 0xff);
      if (mv64x60_i2c_wait_for_status(status) < 0)
            return -1;
      return in_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_DATA)) & 0xff;
}

static int mv64x60_i2c_write_byte(int data, int control, int status)
{
      out_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_DATA), data & 0xff);
      out_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_CONTROL), control & 0xff);
      return mv64x60_i2c_wait_for_status(status);
}

int mv64x60_i2c_read(u32 devaddr, u8 *buf, u32 offset, u32 offset_size,
             u32 count)
{
      int i;
      int data;
      int control;
      int status;

      if (ctlr_base == NULL)
            return -1;

      /* send reset */
      out_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_SOFT_RESET), 0);
      out_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_SLAVE_ADDR), 0);
      out_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_EXT_SLAVE_ADDR), 0);
      out_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_BAUD), (4 << 3) | 0x4);

      if (mv64x60_i2c_control(MV64x60_I2C_CONTROL_TWSIEN,
                        MV64x60_I2C_STATUS_NO_STATUS) < 0)
            return -1;

      /* send start */
      control = MV64x60_I2C_CONTROL_START | MV64x60_I2C_CONTROL_TWSIEN;
      status = MV64x60_I2C_STATUS_MAST_START;
      if (mv64x60_i2c_control(control, status) < 0)
            return -1;

      /* select device for writing */
      data = devaddr & ~0x1;
      control = MV64x60_I2C_CONTROL_TWSIEN;
      status = MV64x60_I2C_STATUS_MAST_WR_ADDR_ACK;
      if (mv64x60_i2c_write_byte(data, control, status) < 0)
            return -1;

      /* send offset of data */
      control = MV64x60_I2C_CONTROL_TWSIEN;
      status = MV64x60_I2C_STATUS_MAST_WR_ACK;
      if (offset_size > 1) {
            if (mv64x60_i2c_write_byte(offset >> 8, control, status) < 0)
                  return -1;
      }
      if (mv64x60_i2c_write_byte(offset, control, status) < 0)
            return -1;

      /* resend start */
      control = MV64x60_I2C_CONTROL_START | MV64x60_I2C_CONTROL_TWSIEN;
      status = MV64x60_I2C_STATUS_MAST_REPEAT_START;
      if (mv64x60_i2c_control(control, status) < 0)
            return -1;

      /* select device for reading */
      data = devaddr | 0x1;
      control = MV64x60_I2C_CONTROL_TWSIEN;
      status = MV64x60_I2C_STATUS_MAST_RD_ADDR_ACK;
      if (mv64x60_i2c_write_byte(data, control, status) < 0)
            return -1;

      /* read all but last byte of data */
      control = MV64x60_I2C_CONTROL_ACK | MV64x60_I2C_CONTROL_TWSIEN;
      status = MV64x60_I2C_STATUS_MAST_RD_DATA_ACK;

      for (i=1; i<count; i++) {
            data = mv64x60_i2c_read_byte(control, status);
            if (data < 0) {
                  printf("errors on iteration %d\n", i);
                  return -1;
            }
            *buf++ = data;
      }

      /* read last byte of data */
      control = MV64x60_I2C_CONTROL_TWSIEN;
      status = MV64x60_I2C_STATUS_MAST_RD_DATA_NO_ACK;
      data = mv64x60_i2c_read_byte(control, status);
      if (data < 0)
            return -1;
      *buf++ = data;

      /* send stop */
      control = MV64x60_I2C_CONTROL_STOP | MV64x60_I2C_CONTROL_TWSIEN;
      status = MV64x60_I2C_STATUS_NO_STATUS;
      if (mv64x60_i2c_control(control, status) < 0)
            return -1;

      return count;
}

int mv64x60_i2c_open(void)
{
      u32 v;
      void *devp;

      devp = find_node_by_compatible(NULL, "marvell,mv64360-i2c");
      if (devp == NULL)
            goto err_out;
      if (getprop(devp, "virtual-reg", &v, sizeof(v)) != sizeof(v))
            goto err_out;

      ctlr_base = (u8 *)v;
      return 0;

err_out:
      return -1;
}

void mv64x60_i2c_close(void)
{
      ctlr_base = NULL;
}

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