/*
   * Copyright 2013 Texas Instruments, Inc.
   * Author: Dan Murphy <dmurphy@ti.com>
   *
   * Derived work from the pca953x.c driver
   *
   * This program is free software; you can redistribute it and/or
   * modify it under the terms of the GNU General Public License as
   * published by the Free Software Foundation; either version 2 of
   * the License, or (at your option) any later version.
   *
   * 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
   */
  
  #include <common.h>
  #include <i2c.h>
  #include <tca642x.h>
  
  /* tca642x register address definitions */
  struct tca642x_bank_info tca642x_regs[] = {
  	{ .input_reg = 0x00,
  	  .output_reg = 0x04,
  	  .polarity_reg = 0x08,
  	  .configuration_reg = 0x0c },
  	{ .input_reg = 0x01,
  	  .output_reg = 0x05,
  	  .polarity_reg = 0x09,
  	  .configuration_reg = 0x0d },
  	{ .input_reg = 0x02,
  	  .output_reg = 0x06,
  	  .polarity_reg = 0x0a,
  	  .configuration_reg = 0x0e },
  };
  
  /*
   * Modify masked bits in register
   */
  static int tca642x_reg_write(uchar chip, uint8_t addr,
  		uint8_t reg_bit, uint8_t data)
  {
  	uint8_t valw;
  	int org_bus_num;
  	int ret;
  
  	org_bus_num = i2c_get_bus_num();
  	i2c_set_bus_num(CONFIG_SYS_I2C_TCA642X_BUS_NUM);
  
  	if (i2c_read(chip, addr, 1, (uint8_t *)&valw, 1)) {
  		printf("Could not read before writing
  ");
  		ret = -1;
  		goto error;
  	}
  	valw &= ~reg_bit;
  	valw |= data;
  
  	ret = i2c_write(chip, addr, 1, (u8 *)&valw, 1);
  
  error:
  	i2c_set_bus_num(org_bus_num);
  	return ret;
  }
  
  static int tca642x_reg_read(uchar chip, uint8_t addr, uint8_t *data)
  {
  	uint8_t valw;
  	int org_bus_num;
  	int ret = 0;
  
  	org_bus_num = i2c_get_bus_num();
  	i2c_set_bus_num(CONFIG_SYS_I2C_TCA642X_BUS_NUM);
  	if (i2c_read(chip, addr, 1, (u8 *)&valw, 1)) {
  		ret = -1;
  		goto error;
  	}
  
  	*data = valw;
  
  error:
  	i2c_set_bus_num(org_bus_num);
  	return ret;
  }
  
  /*
   * Set output value of IO pins in 'reg_bit' to corresponding value in 'data'
   * 0 = low, 1 = high
   */
  int tca642x_set_val(uchar chip, uint8_t gpio_bank,
  					uint8_t reg_bit, uint8_t data)
  {
  	uint8_t out_reg = tca642x_regs[gpio_bank].output_reg;
  
  	return tca642x_reg_write(chip, out_reg, reg_bit, data);
  }
  
  /*
   * Set read polarity of IO pins in 'reg_bit' to corresponding value in 'data'
   * 0 = read pin value, 1 = read inverted pin value
   */
  int tca642x_set_pol(uchar chip, uint8_t gpio_bank,
  					uint8_t reg_bit, uint8_t data)
  {
  	uint8_t pol_reg = tca642x_regs[gpio_bank].polarity_reg;
  
  	return tca642x_reg_write(chip, pol_reg, reg_bit, data);
  }
  
  /*
   * Set direction of IO pins in 'reg_bit' to corresponding value in 'data'
   * 0 = output, 1 = input
   */
  int tca642x_set_dir(uchar chip, uint8_t gpio_bank,
  					uint8_t reg_bit, uint8_t data)
  {
  	uint8_t config_reg = tca642x_regs[gpio_bank].configuration_reg;
  
  	return tca642x_reg_write(chip, config_reg, reg_bit, data);
  }
  
  /*
   * Read current logic level of all IO pins
   */
  int tca642x_get_val(uchar chip, uint8_t gpio_bank)
  {
  	uint8_t val;
  	uint8_t in_reg = tca642x_regs[gpio_bank].input_reg;
  
  	if (tca642x_reg_read(chip, in_reg, &val) < 0)
  		return -1;
  
  	return (int)val;
  }
  
  /*
   * Set the inital register states for the tca642x gpio expander
   */
  int tca642x_set_inital_state(uchar chip, struct tca642x_bank_info init_data[])
  {
  	int i, ret;
  	uint8_t config_reg;
  	uint8_t polarity_reg;
  	uint8_t output_reg;
  
  	for (i = 0; i < 3; i++) {
  		config_reg = tca642x_regs[i].configuration_reg;
  		ret = tca642x_reg_write(chip, config_reg, 0xff,
  				init_data[i].configuration_reg);
  		polarity_reg = tca642x_regs[i].polarity_reg;
  		ret = tca642x_reg_write(chip, polarity_reg, 0xff,
  				init_data[i].polarity_reg);
  		output_reg = tca642x_regs[i].output_reg;
  		ret = tca642x_reg_write(chip, output_reg, 0xff,
  				init_data[i].output_reg);
  	}
  
  	return ret;
  }
  
  #ifdef CONFIG_CMD_TCA642X
  /*
   * Display tca642x information
   */
  static int tca642x_info(uchar chip)
  {
  	int i, j;
  	uint8_t data;
  
  	printf("tca642x@ 0x%x (%d pins):
  ", chip, 24);
  	for (i = 0; i < 3; i++) {
  		printf("Bank %i
  ", i);
  		if (tca642x_reg_read(chip,
  				     tca642x_regs[i].configuration_reg,
  				     &data) < 0)
  			return -1;
  		printf("\tConfiguration: ");
  		for (j = 7; j >= 0; j--)
  			printf("%c", data & (1 << j) ? 'i' : 'o');
  		printf("
  ");
  
  		if (tca642x_reg_read(chip,
  				     tca642x_regs[i].polarity_reg, &data) < 0)
  			return -1;
  		printf("\tPolarity: ");
  		for (j = 7; j >= 0; j--)
  			printf("%c", data & (1 << j) ? '1' : '0');
  		printf("
  ");
  
  		if (tca642x_reg_read(chip,
  				     tca642x_regs[i].input_reg, &data) < 0)
  			return -1;
  		printf("\tInput value: ");
  		for (j = 7; j >= 0; j--)
  			printf("%c", data & (1 << j) ? '1' : '0');
  		printf("
  ");
  
  		if (tca642x_reg_read(chip,
  				     tca642x_regs[i].output_reg, &data) < 0)
  			return -1;
  		printf("\tOutput value: ");
  		for (j = 7; j >= 0; j--)
  			printf("%c", data & (1 << j) ? '1' : '0');
  		printf("
  ");
  	}
  
  	return 0;
  }
  
  cmd_tbl_t cmd_tca642x[] = {
  	U_BOOT_CMD_MKENT(device, 3, 0, (void *)TCA642X_CMD_DEVICE, "", ""),
  	U_BOOT_CMD_MKENT(output, 4, 0, (void *)TCA642X_CMD_OUTPUT, "", ""),
  	U_BOOT_CMD_MKENT(input, 3, 0, (void *)TCA642X_CMD_INPUT, "", ""),
  	U_BOOT_CMD_MKENT(invert, 4, 0, (void *)TCA642X_CMD_INVERT, "", ""),
  	U_BOOT_CMD_MKENT(info, 2, 0, (void *)TCA642X_CMD_INFO, "", ""),
  };
  
  int do_tca642x(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
  {
  	static uchar chip = CONFIG_SYS_I2C_TCA642X_ADDR;
  	int ret = CMD_RET_USAGE, val;
  	uint8_t gpio_bank = 0;
  	uint8_t bank_shift;
  	ulong ul_arg2 = 0;
  	ulong ul_arg3 = 0;
  	cmd_tbl_t *c;
  
  	c = find_cmd_tbl(argv[1], cmd_tca642x, ARRAY_SIZE(cmd_tca642x));
  
  	/* All commands but "device" require 'maxargs' arguments */
  	if (!c ||
  	    !((argc == (c->maxargs)) ||
  	    (((int)c->cmd == TCA642X_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, 10);
  
  	/* arg3 used as pin or invert value */
  	if (argc > 3) {
  		ul_arg3 = simple_strtoul(argv[3], NULL, 10) & 0x1;
  		if (ul_arg2 <= 7) {
  			gpio_bank = 0;
  		} else if ((ul_arg2 >= 10) && (ul_arg2 <= 17)) {
  			gpio_bank = 1;
  		} else if ((ul_arg2 >= 20) && (ul_arg2 <= 27)) {
  			gpio_bank = 2;
  		} else {
  			printf("Requested pin is not available
  ");
  			ret = CMD_RET_FAILURE;
  			goto error;
  		}
  	}
  
  	switch ((int)c->cmd) {
  	case TCA642X_CMD_INFO:
  		ret = tca642x_info(chip);
  		if (ret)
  			ret = CMD_RET_FAILURE;
  		break;
  
  	case TCA642X_CMD_DEVICE:
  		if (argc == 3)
  			chip = (uint8_t)ul_arg2;
  		printf("Current device address: 0x%x
  ", chip);
  		ret = CMD_RET_SUCCESS;
  		break;
  
  	case TCA642X_CMD_INPUT:
  		bank_shift = ul_arg2 - (gpio_bank * 10);
  		ret = tca642x_set_dir(chip, gpio_bank, (1 << bank_shift),
  				TCA642X_DIR_IN << bank_shift);
  		val = (tca642x_get_val(chip, gpio_bank) &
  				(1 << bank_shift)) != 0;
  
  		if (ret)
  			ret = CMD_RET_FAILURE;
  		else
  			printf("chip 0x%02x, pin 0x%lx = %d
  ", chip,
  			       ul_arg2, val);
  		break;
  
  	case TCA642X_CMD_OUTPUT:
  		bank_shift = ul_arg2 - (gpio_bank * 10);
  		ret = tca642x_set_dir(chip, gpio_bank, (1 << bank_shift),
  				(TCA642X_DIR_OUT << bank_shift));
  		if (!ret)
  			ret = tca642x_set_val(chip,
  					      gpio_bank, (1 << bank_shift),
  					      (ul_arg3 << bank_shift));
  		if (ret)
  			ret = CMD_RET_FAILURE;
  		break;
  
  	case TCA642X_CMD_INVERT:
  		bank_shift = ul_arg2 - (gpio_bank * 10);
  		ret = tca642x_set_pol(chip, gpio_bank, (1 << bank_shift),
  					(ul_arg3 << bank_shift));
  		if (ret)
  			ret = CMD_RET_FAILURE;
  		break;
  	}
  error:
  	if (ret == CMD_RET_FAILURE)
  		eprintf("Error talking to chip at 0x%x
  ", chip);
  
  	return ret;
  }
  
  U_BOOT_CMD(
  	tca642x,	5,	1,	do_tca642x,
  	"tca642x gpio access",
  	"device [dev]
  "
  	"	- show or set current device address
  "
  	"tca642x info
  "
  	"	- display info for current chip
  "
  	"tca642x output pin 0|1
  "
  	"	- set pin as output and drive low or high
  "
  	"tca642x invert pin 0|1
  "
  	"	- disable/enable polarity inversion for reads
  "
  	"tca642x input pin
  "
  	"	- set pin as input and read value"
  );
  
  #endif /* CONFIG_CMD_TCA642X */