/*
 * 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 <command.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(CFG_SYS_I2C_TCA642X_BUS_NUM);

        if (i2c_read(chip, addr, 1, (uint8_t *)&valw, 1)) {
                printf("Could not read before writing\n");
                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(CFG_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;
}

#if defined(CONFIG_CMD_TCA642X) && !defined(CONFIG_SPL_BUILD)
/*
 * Display tca642x information
 */
static int tca642x_info(uchar chip)
{
        int i, j;
        uint8_t data;

        printf("tca642x@ 0x%x (%d pins):\n", chip, 24);
        for (i = 0; i < 3; i++) {
                printf("Bank %i\n", 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("\n");

                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("\n");

                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("\n");

                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("\n");
        }

        return 0;
}

static int tca642x_get_bank(int pin)
{
        int gpio_bank;

        if (pin <= 7) {
                gpio_bank = 0;
        } else if ((pin >= 10) && (pin <= 17)) {
                gpio_bank = 1;
        } else if ((pin >= 20) && (pin <= 27)) {
                gpio_bank = 2;
        } else {
                printf("Requested pin is not available\n");
                gpio_bank = -1;
        }

        return gpio_bank;
}

static struct cmd_tbl 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, "", ""),
};

static int do_tca642x(struct cmd_tbl *cmdtp, int flag, int argc,
                      char *const argv[])
{
        static uchar chip = CFG_SYS_I2C_TCA642X_ADDR;
        int ret = CMD_RET_USAGE, val;
        int gpio_bank = 0;
        uint8_t bank_shift;
        ulong ul_arg2 = 0;
        ulong ul_arg3 = 0;
        struct cmd_tbl *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 = dectoul(argv[2], NULL);

        /* arg3 used as pin or invert value */
        if (argc > 3)
                ul_arg3 = dectoul(argv[3], NULL) & 0x1;

        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\n", chip);
                ret = CMD_RET_SUCCESS;
                break;

        case TCA642X_CMD_INPUT:
                gpio_bank = tca642x_get_bank(ul_arg2);
                if (gpio_bank < 0) {
                        ret = CMD_RET_FAILURE;
                        goto error;
                }
                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\n", chip,
                               ul_arg2, val);
                break;

        case TCA642X_CMD_OUTPUT:
                gpio_bank = tca642x_get_bank(ul_arg2);
                if (gpio_bank < 0) {
                        ret = CMD_RET_FAILURE;
                        goto error;
                }
                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:
                gpio_bank = tca642x_get_bank(ul_arg2);
                if (gpio_bank < 0) {
                        ret = CMD_RET_FAILURE;
                        goto error;
                }
                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\n", chip);

        return ret;
}

U_BOOT_CMD(
        tca642x,        5,      1,      do_tca642x,
        "tca642x gpio access",
        "device [dev]\n"
        "       - show or set current device address\n"
        "tca642x info\n"
        "       - display info for current chip\n"
        "tca642x output pin 0|1\n"
        "       - set pin as output and drive low or high\n"
        "tca642x invert pin 0|1\n"
        "       - disable/enable polarity inversion for reads\n"
        "tca642x input pin\n"
        "       - set pin as input and read value"
);

#endif /* CONFIG_CMD_TCA642X */