/*
 * 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 and 8 bit I2C gpio expanders (eg pca9537, pca9557, etc)
 * TODO: support additional devices with more than 8-bits GPIO
 */

#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,
};

/*
 * Modify masked bits in register
 */
static int pca953x_reg_write(uint8_t chip, uint addr, uint mask, uint data)
{
        uint8_t val;

        if (i2c_read(chip, addr, 1, &val, 1))
                return -1;

        val &= ~mask;
        val |= data;

        return i2c_write(chip, addr, 1, &val, 1);
}

/*
 * 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)
{
        uint8_t val;

        if (i2c_read(chip, 0, 1, &val, 1))
                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;
        uint8_t data;

        printf("pca953x@ 0x%x:\n\n", chip);
        printf("gpio pins: 76543210\n");
        printf("-------------------\n");

        if (i2c_read(chip, PCA953X_CONF, 1, &data, 1))
                return -1;
        printf("conf:      ");
        for (i = 7; i >= 0; i--)
                printf("%c", data & (1 << i) ? 'i' : 'o');
        printf("\n");

        if (i2c_read(chip, PCA953X_POL, 1, &data, 1))
                return -1;
        printf("invert:    ");
        for (i = 7; i >= 0; i--)
                printf("%c", data & (1 << i) ? '1' : '0');
        printf("\n");

        if (i2c_read(chip, PCA953X_IN, 1, &data, 1))
                return -1;
        printf("input:     ");
        for (i = 7; i >= 0; i--)
                printf("%c", data & (1 << i) ? '1' : '0');
        printf("\n");

        if (i2c_read(chip, PCA953X_OUT, 1, &data, 1))
                return -1;
        printf("output:    ");
        for (i = 7; i >= 0; i--)
                printf("%c", data & (1 << i) ? '1' : '0');
        printf("\n");

        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 *argv[])
{
        static uint8_t chip = CONFIG_SYS_I2C_PCA953X_ADDR;
        int 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))))) {
                cmd_usage(cmdtp);
                return 1;
        }

        /* 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:
                return pca953x_info(chip);
#endif
        case PCA953X_CMD_DEVICE:
                if (argc == 3)
                        chip = (uint8_t)ul_arg2;
                printf("Current device address: 0x%x\n", chip);
                return 0;
        case PCA953X_CMD_INPUT:
                pca953x_set_dir(chip, (1 << ul_arg2),
                                PCA953X_DIR_IN << ul_arg2);
                val = (pca953x_get_val(chip) & (1 << ul_arg2)) != 0;

                printf("chip 0x%02x, pin 0x%lx = %d\n", chip, ul_arg2, val);
                return val;
        case PCA953X_CMD_OUTPUT:
                pca953x_set_dir(chip, (1 << ul_arg2),
                                (PCA953X_DIR_OUT << ul_arg2));
                return pca953x_set_val(chip, (1 << ul_arg2),
                                        (ul_arg3 << ul_arg2));
        case PCA953X_CMD_INVERT:
                return pca953x_set_pol(chip, (1 << ul_arg2),
                                        (ul_arg3 << ul_arg2));
        default:
                /* We should never get here */
                return 1;
        }
}

U_BOOT_CMD(
        pca953x,        5,      1,      do_pca953x,
        "pca953x gpio access",
        "device [dev]\n"
        "       - show or set current device address\n"
#ifdef CONFIG_CMD_PCA953X_INFO
        "pca953x info\n"
        "       - display info for current chip\n"
#endif
        "pca953x output pin 0|1\n"
        "       - set pin as output and drive low or high\n"
        "pca953x invert pin 0|1\n"
        "       - disable/enable polarity inversion for reads\n"
        "pca953x intput pin\n"
        "       - set pin as input and read value"
);

#endif /* CONFIG_CMD_PCA953X */