/*
 * Copyright (C) 2021 Denis 'GNUtoo' Carikli <GNUtoo@cyberdimension.org>
 *
 * 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 3 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, see <https://www.gnu.org/licenses/>.
 */

#include <assert.h>
#include <errno.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
#include <string.h>

#include "exynos4412_gpios_data.h"

/*
 * Generic functions
 */
static int get_2bit_field_value(uint32_t register_value, int gpio_offset)
{
	return ((register_value >> (2*gpio_offset)) & 3);
}

/*
 * <GPIO>CON
 */

static char *gpio_direction_str(int value)
{
	/* The GP<x>CON field size is 4 bits. So the maximum value it can take
	 * is 0xf. So to convert that to string, if we add the trailing \0, the
	 * size of the the string is 4.
	 */
	static char result[4] = { 0 };

	switch (value) {
	case GPIO_INPUT:
		return "GPIO_INPUT";
	case GPIO_OUTPUT:
		return "GPIO_OUTPUT";
	default:
		snprintf(result, sizeof(result), "0x%x", value);
		return (char*)result;
	}
}

static int get_con_value(uint32_t register_value, int gpio_offset)
{
	return ((register_value >> (gpio_offset * 4)) & 0xf);
}

/*
 * <GPIO>DAT
 */

static char *gpio_value_str(int value)
{
	/* The GP<x>DAT field size is 1 bit. But when the pin is not input nor
	 * output, its value is undefined.
	 */
	switch (value) {
	case GPIO_VALUE_LOW:
		return "GPIO_VALUE_LOW";
	case GPIO_VALUE_HIGH:
		return "GPIO_VALUE_HIGH";
	case GPIO_VALUE_UNDEFINED:
		return "GPIO_VALUE_UNDEFINED";
	}

	assert(false); /* This should normally not be reached */
	return "";     /* Avoid -Werror=return-type */
}

static int get_dat_value(uint32_t register_value, int gpio_offset)
{
	return ((register_value >> (gpio_offset)) & 1);
}

/*
 * <GPIO>DRV
 */

static char *gpio_drive_str(int value)
{
	/* The GP<x>DRV field size is 2 bit. */
	switch (value) {
	case GPIO_DRIVE_1X:
		return "GPIO_DRIVE_1X";
	case GPIO_DRIVE_2X:
		return "GPIO_DRIVE_2X";
	case GPIO_DRIVE_3X:
		return "GPIO_DRIVE_3X";
	case GPIO_DRIVE_4X:
		return "GPIO_DRIVE_4X";
	}

	assert(false); /* This should normally not be reached */
	return "";     /* Avoid -Werror=return-type */
}

/*
 * <GPIO>PUD
 */

static char *gpio_resistor_str(int value)
{
	/* The GP<x>PUD field size is 2 bit. */
	switch (value) {
	case GPIO_RESISTORS_PULLDOWN_DISABLE:
		return "GPIO_RESISTORS_PULLDOWN_DISABLE";
	case GPIO_RESISTORS_ENABLE_PULL_DOWN:
		return "GPIO_RESISTORS_ENABLE_PULL_DOWN";
	case GPIO_RESISTORS_RESERVED:
		return "GPIO_RESISTORS_RESERVED";
	case GPIO_RESISTORS_ENABLE_PULL_UP:
		return "GPIO_RESISTORS_ENABLE_PULL_UP";
	}

	assert(false); /* This should normally not be reached */
	return "";     /* Avoid -Werror=return-type */
}

/*
 * <GPIO>CONPDN
 */

static char *gpio_power_down_str(int value)
{
	/* The GP<x>CON field size is 2 bits. */

	switch (value) {
	case GPIO_POWER_DOWN_OUTPUT_LOW:
		return "GPIO_POWER_DOWN_OUTPUT_LOW";
	case GPIO_POWER_DOWN_OUTPUT_HIGH:
		return "GPIO_POWER_DOWN_OUTPUT_HIGH";
	case GPIO_POWER_DOWN_INPUT:
		return "GPIO_POWER_DOWN_INPUT";
	case GPIO_POWER_DOWN_PREVIOUS_STATE:
		return "GPIO_POWER_DOWN_PREVIOUS_STATE";
	}

	assert(false); /* This should normally not be reached */
	return "";     /* Avoid -Werror=return-type */
}

struct gpio_bank_data gpio_banks_data[] = {
	{
		.name = "gpf0",
		.nr_gpios = 8,
		.base = 0x11400000,
		.offset = 0x0180,
	},
	{
		.name = "gpf1",
		.nr_gpios = 8,
		.base = 0x11400000,
		.offset = 0x01a0,
	},
	{
		.name = "gpf2",
		.nr_gpios = 8,
		.base = 0x11400000,
		.offset = 0x01c0,
	},
	{
		.name = "gpf3",
		.nr_gpios = 6,
		.base = 0x11400000,
		.offset = 0x01e0,
	},
	{
		.name = "gpj0",
		.nr_gpios = 8,
		.base = 0x11400000,
		.offset = 0x0240,
	},
	{
		.name = "gpj1",
		.nr_gpios = 5,
		.base = 0x11400000,
		.offset = 0x0260,
	},
	{
		.name = "gpl0",
		.nr_gpios = 7,
		.base = 0x11000000,
		.offset = 0x00c0,
	},
	{
		.name = "gpl1",
		.nr_gpios = 2,
		.base = 0x11000000,
		.offset = 0x00e0,
	},
	{
		.name = "gpl2",
		.nr_gpios = 8,
		.base = 0x11000000,
		.offset = 0x0100,
	},
	{
		.name = "gpm0",
		.nr_gpios = 8,
		.base = 0x11000000,
		.offset = 0x0260,
	},
	{
		.name = "gpm1",
		.nr_gpios = 7,
		.base = 0x11000000,
		.offset = 0x0280,
	},
	{
		.name = "gpm2",
		.nr_gpios = 5,
		.base = 0x11000000,
		.offset = 0x02a0,
	},
	{
		.name = "gpm3",
		.nr_gpios = 8,
		.base = 0x11000000,
		.offset = 0x02c0,
	},
	{
		.name = "gpm4",
		.nr_gpios = 8,
		.base = 0x11000000,
		.offset = 0x02e0,
	},
	{
		.name = "gpx0",
		.nr_gpios = 8,
		.base = 0x11000000,
		.offset = 0x0c00,
	},
	{
		.name = "gpx1",
		.nr_gpios = 8,
		.base = 0x11000000,
		.offset = 0x0c20,
	},
	{
		.name = "gpx2",
		.nr_gpios = 8,
		.base = 0x11000000,
		.offset = 0x0c40,
	},
	{
		.name = "gpx3",
		.nr_gpios = 8,
		.base = 0x11000000,
		.offset = 0x0c60,
	},
	{
		.name = "gpy0",
		.nr_gpios = 6,
		.base = 0x11000000,
		.offset = 0x0120,
	},
	{
		.name = "gpy1",
		.nr_gpios = 4,
		.base = 0x11000000,
		.offset = 0x0140,
	},
	{
		.name = "gpy2",
		.nr_gpios = 6,
		.base = 0x11000000,
		.offset = 0x0160,
	},
	{
		/* Sentinel */
	},
};

struct gpio_register_data gpio_registers_data[] = {
	{
		.name = "con",
		.get_value = get_con_value,
		.offset = 0x00,
		.value_str = gpio_direction_str,
	},
	{
		.name = "dat",
		.get_value = get_dat_value,
		.offset = 0x04,
		.value_str = gpio_value_str,
	},
	{
		.name = "pud",
		.get_value = get_2bit_field_value,
		.offset = 0x08,
		.value_str = gpio_resistor_str,
	},
	{
		.name = "drv",
		.get_value = get_2bit_field_value,
		.offset = 0x0c,
		.value_str = gpio_drive_str,
	},
	{
		.name = "con-pdn",
		.get_value = get_2bit_field_value,
		.offset = 0x10,
		.value_str = gpio_power_down_str,
	},
	{
		.name = "pud-pdn",
		.get_value = get_2bit_field_value,
		.offset = 0x14,
		.value_str = gpio_resistor_str,
	},
};

struct gpio_bank_data *get_gpio_bank_data(char *bank)
{
	int i = 0;

	while (1) {
		if (gpio_banks_data[i].name == NULL)
			break;

		if (!strcmp(gpio_banks_data[i].name, bank))
			return &(gpio_banks_data[i]);

		i++;
	}

	return NULL;
}

struct gpio_register_data *get_gpio_register_data(char *register_name)
{

	int i = 0;

	while (1) {
		if (gpio_registers_data[i].name == NULL)
			break;

		if (!strcmp(gpio_registers_data[i].name, register_name))
			return &(gpio_registers_data[i]);

		i++;
	}

	return NULL;
}

void print_gpio_banks_data(void)
{
	int i = 0;

	while (1) {
		if (gpio_banks_data[i].name == NULL)
			break;

		printf("%s[%d] {\n", gpio_banks_data[i].name,
		       gpio_banks_data[i].nr_gpios);
		printf("\toffset: 0x%x\n", gpio_banks_data[i].offset);
		printf("}\n");

		i++;
	}
}

int decode_gpio_data(int debug, char *bank, uint32_t gpio_offset,
		     char* gpio_register_name, uint32_t *virt_addr)
{
	struct gpio_bank_data *gpio_bank_data;
	struct gpio_register_data *gpio_register_data;

	uint32_t *addr;
	uint32_t register_value;

	gpio_bank_data = get_gpio_bank_data(bank);
	if (gpio_bank_data == NULL) {
		errno = EINVAL;
		return -1;
	}

	gpio_register_data = get_gpio_register_data(gpio_register_name);
	if (gpio_register_data == NULL) {
		errno = EINVAL;
		return -1;
	}

	addr = virt_addr + gpio_bank_data->offset + gpio_register_data->offset;
	register_value = *virt_addr;

	if (debug)
		printf("%s: %s: offset 0x%x value: 0x%x\n", __func__, bank,
		       addr - virt_addr, register_value);

	return gpio_register_data->get_value(register_value, gpio_offset);
}

char *gpio_data_str(char* gpio_register_name, uint32_t register_value)
{
	struct gpio_register_data *gpio_register_data;

	gpio_register_data = get_gpio_register_data(gpio_register_name);
	if (gpio_register_data == NULL) {
		errno = EINVAL;
		return NULL;
	}

	return gpio_register_data->value_str(register_value);
}

off_t get_gpio_register_offset(int debug, char *gpio_bank_name,
			       char *register_name)
{
	struct gpio_bank_data *gpio_bank_data;
	struct gpio_register_data *gpio_register_data;
	off_t gpio_hardware_block_offset;
	off_t offset = 0;

	gpio_bank_data = get_gpio_bank_data(gpio_bank_name);
	if (gpio_bank_data == NULL) {
		errno = EINVAL;
		return -1;
	}

	gpio_register_data = get_gpio_register_data(register_name);
	if (gpio_register_data == NULL) {
		errno = EINVAL;
		return -1;
	}

	if (gpio_bank_data->base == 0x11400000)
		gpio_hardware_block_offset = 0x400000;

	offset = gpio_hardware_block_offset + gpio_bank_data->offset + gpio_register_data->offset;

	return offset;
}

int get_bank_gpio_numbers(int debug, char *gpio_bank_name)
{
	struct gpio_bank_data *gpio_bank_data;

	gpio_bank_data = get_gpio_bank_data(gpio_bank_name);
	if (gpio_bank_data == NULL) {
		errno = EINVAL;
		return -1;
	}

	return gpio_bank_data->nr_gpios;
}