/*
   * Copyright 2008 Extreme Engineering Solutions, Inc.
   *
   * This program is free software; you can redistribute it and/or
   * modify it under the terms of the GNU General Public License
   * Version 2 as published by the Free Software Foundation.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
   * MA 02111-1307 USA
   */
  
  /*
   * Driver for NXP's 4, 8 and 16 bit I2C gpio expanders (eg pca9537, pca9557,
   * pca9539, etc)
   */
  
  #include <common.h>
  #include <i2c.h>
  #include <pca953x.h>
  
  /* Default to an address that hopefully won't corrupt other i2c devices */
  #ifndef CONFIG_SYS_I2C_PCA953X_ADDR
  #define CONFIG_SYS_I2C_PCA953X_ADDR	(~0)
  #endif
  
  enum {
  	PCA953X_CMD_INFO,
  	PCA953X_CMD_DEVICE,
  	PCA953X_CMD_OUTPUT,
  	PCA953X_CMD_INPUT,
  	PCA953X_CMD_INVERT,
  };
  
  #ifdef CONFIG_SYS_I2C_PCA953X_WIDTH
  struct pca953x_chip_ngpio {
  	uint8_t chip;
  	uint8_t ngpio;
  };
  
  static struct pca953x_chip_ngpio pca953x_chip_ngpios[] =
      CONFIG_SYS_I2C_PCA953X_WIDTH;
  
  /*
   * Determine the number of GPIO pins supported. If we don't know we assume
   * 8 pins.
   */
  static int pca953x_ngpio(uint8_t chip)
  {
  	int i;
  
  	for (i = 0; i < ARRAY_SIZE(pca953x_chip_ngpios); i++)
  		if (pca953x_chip_ngpios[i].chip == chip)
  			return pca953x_chip_ngpios[i].ngpio;
  
  	return 8;
  }
  #else
  static int pca953x_ngpio(uint8_t chip)
  {
  	return 8;
  }
  #endif
  
  /*
   * Modify masked bits in register
   */
  static int pca953x_reg_write(uint8_t chip, uint addr, uint mask, uint data)
  {
  	uint8_t valb;
  	uint16_t valw;
  
  	if (pca953x_ngpio(chip) <= 8) {
  		if (i2c_read(chip, addr, 1, &valb, 1))
  			return -1;
  
  		valb &= ~mask;
  		valb |= data;
  
  		return i2c_write(chip, addr, 1, &valb, 1);
  	} else {
  		if (i2c_read(chip, addr << 1, 1, (u8*)&valw, 2))
  			return -1;
  
  		valw &= ~mask;
  		valw |= data;
  
  		return i2c_write(chip, addr << 1, 1, (u8*)&valw, 2);
  	}
  }
  
  static int pca953x_reg_read(uint8_t chip, uint addr, uint *data)
  {
  	uint8_t valb;
  	uint16_t valw;
  
  	if (pca953x_ngpio(chip) <= 8) {
  		if (i2c_read(chip, addr, 1, &valb, 1))
  			return -1;
  		*data = (int)valb;
  	} else {
  		if (i2c_read(chip, addr << 1, 1, (u8*)&valw, 2))
  			return -1;
  		*data = (int)valw;
  	}
  	return 0;
  }
  
  /*
   * Set output value of IO pins in 'mask' to corresponding value in 'data'
   * 0 = low, 1 = high
   */
  int pca953x_set_val(uint8_t chip, uint mask, uint data)
  {
  	return pca953x_reg_write(chip, PCA953X_OUT, mask, data);
  }
  
  /*
   * Set read polarity of IO pins in 'mask' to corresponding value in 'data'
   * 0 = read pin value, 1 = read inverted pin value
   */
  int pca953x_set_pol(uint8_t chip, uint mask, uint data)
  {
  	return pca953x_reg_write(chip, PCA953X_POL, mask, data);
  }
  
  /*
   * Set direction of IO pins in 'mask' to corresponding value in 'data'
   * 0 = output, 1 = input
   */
  int pca953x_set_dir(uint8_t chip, uint mask, uint data)
  {
  	return pca953x_reg_write(chip, PCA953X_CONF, mask, data);
  }
  
  /*
   * Read current logic level of all IO pins
   */
  int pca953x_get_val(uint8_t chip)
  {
  	uint val;
  
  	if (pca953x_reg_read(chip, PCA953X_IN, &val) < 0)
  		return -1;
  
  	return (int)val;
  }
  
  #ifdef CONFIG_CMD_PCA953X
  #ifdef CONFIG_CMD_PCA953X_INFO
  /*
   * Display pca953x information
   */
  static int pca953x_info(uint8_t chip)
  {
  	int i;
  	uint data;
  	int nr_gpio = pca953x_ngpio(chip);
  	int msb = nr_gpio - 1;
  
  	printf("pca953x@ 0x%x (%d pins):
  
  ", chip, nr_gpio);
  	printf("gpio pins: ");
  	for (i = msb; i >= 0; i--)
  		printf("%x", i);
  	printf("
  ");
  	for (i = 11 + nr_gpio; i > 0; i--)
  		printf("-");
  	printf("
  ");
  
  	if (pca953x_reg_read(chip, PCA953X_CONF, &data) < 0)
  		return -1;
  	printf("conf:      ");
  	for (i = msb; i >= 0; i--)
  		printf("%c", data & (1 << i) ? 'i' : 'o');
  	printf("
  ");
  
  	if (pca953x_reg_read(chip, PCA953X_POL, &data) < 0)
  		return -1;
  	printf("invert:    ");
  	for (i = msb; i >= 0; i--)
  		printf("%c", data & (1 << i) ? '1' : '0');
  	printf("
  ");
  
  	if (pca953x_reg_read(chip, PCA953X_IN, &data) < 0)
  		return -1;
  	printf("input:     ");
  	for (i = msb; i >= 0; i--)
  		printf("%c", data & (1 << i) ? '1' : '0');
  	printf("
  ");
  
  	if (pca953x_reg_read(chip, PCA953X_OUT, &data) < 0)
  		return -1;
  	printf("output:    ");
  	for (i = msb; i >= 0; i--)
  		printf("%c", data & (1 << i) ? '1' : '0');
  	printf("
  ");
  
  	return 0;
  }
  #endif /* CONFIG_CMD_PCA953X_INFO */
  
  cmd_tbl_t cmd_pca953x[] = {
  	U_BOOT_CMD_MKENT(device, 3, 0, (void *)PCA953X_CMD_DEVICE, "", ""),
  	U_BOOT_CMD_MKENT(output, 4, 0, (void *)PCA953X_CMD_OUTPUT, "", ""),
  	U_BOOT_CMD_MKENT(input, 3, 0, (void *)PCA953X_CMD_INPUT, "", ""),
  	U_BOOT_CMD_MKENT(invert, 4, 0, (void *)PCA953X_CMD_INVERT, "", ""),
  #ifdef CONFIG_CMD_PCA953X_INFO
  	U_BOOT_CMD_MKENT(info, 2, 0, (void *)PCA953X_CMD_INFO, "", ""),
  #endif
  };
  
  int do_pca953x(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
  {
  	static uint8_t chip = CONFIG_SYS_I2C_PCA953X_ADDR;
  	int ret = CMD_RET_USAGE, val;
  	ulong ul_arg2 = 0;
  	ulong ul_arg3 = 0;
  	cmd_tbl_t *c;
  
  	c = find_cmd_tbl(argv[1], cmd_pca953x, ARRAY_SIZE(cmd_pca953x));
  
  	/* All commands but "device" require 'maxargs' arguments */
  	if (!c || !((argc == (c->maxargs)) ||
  		(((int)c->cmd == PCA953X_CMD_DEVICE) &&
  		 (argc == (c->maxargs - 1))))) {
  		return CMD_RET_USAGE;
  	}
  
  	/* arg2 used as chip number or pin number */
  	if (argc > 2)
  		ul_arg2 = simple_strtoul(argv[2], NULL, 16);
  
  	/* arg3 used as pin or invert value */
  	if (argc > 3)
  		ul_arg3 = simple_strtoul(argv[3], NULL, 16) & 0x1;
  
  	switch ((int)c->cmd) {
  #ifdef CONFIG_CMD_PCA953X_INFO
  	case PCA953X_CMD_INFO:
  		ret = pca953x_info(chip);
  		if (ret)
  			ret = CMD_RET_FAILURE;
  		break;
  #endif
  
  	case PCA953X_CMD_DEVICE:
  		if (argc == 3)
  			chip = (uint8_t)ul_arg2;
  		printf("Current device address: 0x%x
  ", chip);
  		ret = CMD_RET_SUCCESS;
  		break;
  
  	case PCA953X_CMD_INPUT:
  		ret = pca953x_set_dir(chip, (1 << ul_arg2),
  				PCA953X_DIR_IN << ul_arg2);
  		val = (pca953x_get_val(chip) & (1 << ul_arg2)) != 0;
  
  		if (ret)
  			ret = CMD_RET_FAILURE;
  		else
  			printf("chip 0x%02x, pin 0x%lx = %d
  ", chip, ul_arg2,
  									val);
  		break;
  
  	case PCA953X_CMD_OUTPUT:
  		ret = pca953x_set_dir(chip, (1 << ul_arg2),
  				(PCA953X_DIR_OUT << ul_arg2));
  		if (!ret)
  			ret = pca953x_set_val(chip, (1 << ul_arg2),
  						(ul_arg3 << ul_arg2));
  		if (ret)
  			ret = CMD_RET_FAILURE;
  		break;
  
  	case PCA953X_CMD_INVERT:
  		ret = pca953x_set_pol(chip, (1 << ul_arg2),
  					(ul_arg3 << ul_arg2));
  		if (ret)
  			ret = CMD_RET_FAILURE;
  		break;
  	}
  
  	if (ret == CMD_RET_FAILURE)
  		eprintf("Error talking to chip at 0x%x
  ", chip);
  
  	return ret;
  }
  
  U_BOOT_CMD(
  	pca953x,	5,	1,	do_pca953x,
  	"pca953x gpio access",
  	"device [dev]
  "
  	"	- show or set current device address
  "
  #ifdef CONFIG_CMD_PCA953X_INFO
  	"pca953x info
  "
  	"	- display info for current chip
  "
  #endif
  	"pca953x output pin 0|1
  "
  	"	- set pin as output and drive low or high
  "
  	"pca953x invert pin 0|1
  "
  	"	- disable/enable polarity inversion for reads
  "
  	"pca953x input pin
  "
  	"	- set pin as input and read value"
  );
  
  #endif /* CONFIG_CMD_PCA953X */