// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2020 MediaTek Inc.
 *
 * Author: Light Hsieh <light.hsieh@mediatek.com>
 *
 */

#include <linux/module.h>

#include <dt-bindings/pinctrl/mt65xx.h>
#include <linux/gpio.h>
#include <linux/gpio/consumer.h>
#include <../../gpio/gpiolib.h>
#include <asm-generic/gpio.h>
#include <linux/delay.h>
#include "pinctrl-paris.h"

#define MTK_PINCTRL_DEV_NAME "pinctrl_paris"
#define PULL_DELAY 50 /* in ms */
#define FUN_3STATE "gpio_get_value_tristate"

static const char *pinctrl_paris_modname = MTK_PINCTRL_DEV_NAME;
static struct mtk_pinctrl *g_hw;

static void mtk_gpio_find_mtk_pinctrl_dev(void)
{
	struct gpio_desc *gdesc;
	unsigned int pin = ARCH_NR_GPIOS - 1;

	do {
		gdesc = gpio_to_desc(pin);
		if (!gdesc)
			break;
		if (!strncmp(pinctrl_paris_modname,
				gdesc->gdev->chip->label,
				strlen(pinctrl_paris_modname))) {
			g_hw = gpiochip_get_data(gdesc->gdev->chip);
			return;
		}

		pin = (pin + 1) - gdesc->gdev->chip->base;
	} while (pin > 0);
}

int gpio_get_tristate_input(unsigned int pin)
{
	struct mtk_pinctrl *hw = NULL;
	const struct mtk_pin_desc *desc;
	int val, val_up, val_down, ret, pullup, pullen, pull_type;

	if (!g_hw)
		mtk_gpio_find_mtk_pinctrl_dev();
	if (!g_hw)
		return  -ENOTSUPP;
	hw = g_hw;

	if (!hw->soc) {
		pr_notice("invalid gpio chip\n");
		return -EINVAL;
	}

	if (!hw->soc->bias_set_combo) {
		pr_notice("not supported gpio chip\n");
		return -ENOTSUPP;
	}

	if (pin < hw->chip.base) {
		pr_notice(FUN_3STATE ": please use virtual pin number\n");
		return -EINVAL;
	}

	pin -= hw->chip.base;
	if (pin >= hw->soc->npins) {
		pr_notice(FUN_3STATE ": invalid pin number: %u\n",
			pin);
		return -EINVAL;
	}

	desc = (const struct mtk_pin_desc *)&hw->soc->pins[pin];
	ret = mtk_hw_get_value(hw, desc, PINCTRL_PIN_REG_MODE, &val);
	if (ret)
		return ret;
	if (val != 0) {
		pr_notice(FUN_3STATE ":GPIO%d in mode %d, not GPIO mode\n",
			pin, val);
		return -EINVAL;
	}

	ret = hw->soc->bias_get_combo(hw, desc, &pullup, &pullen);
	if (ret)
		return ret;
	if (pullen == 0 ||  pullen == MTK_PUPD_SET_R1R0_00) {
		pr_notice(FUN_3STATE ":GPIO%d not pullen, skip floating test\n",
			pin);
		return gpio_get_value(pin+hw->chip.base);
	}
	if (pullen > MTK_PUPD_SET_R1R0_00)
		pull_type = 1;
	else
		pull_type = 0;

	/* set pullsel as pull-up and get input value */
	pr_notice(FUN_3STATE ":pull up GPIO%d\n", pin);
	ret = hw->soc->bias_set_combo(hw, desc, 1,
		(pull_type ? MTK_PUPD_SET_R1R0_11 : MTK_ENABLE));
	if (ret)
		goto out;
	mdelay(PULL_DELAY);
	val_up = gpio_get_value(pin+hw->chip.base);
	pr_notice(FUN_3STATE ":GPIO%d input %d\n", pin, val_up);

	/* set pullsel as pull-down and get input value */
	pr_notice(FUN_3STATE ":pull down GPIO%d\n", pin);
	ret = hw->soc->bias_set_combo(hw, desc, 0,
		(pull_type ? MTK_PUPD_SET_R1R0_11 : MTK_ENABLE));
	if (ret)
		goto out;
	mdelay(PULL_DELAY);
	val_down = gpio_get_value(pin+hw->chip.base);
	pr_notice(FUN_3STATE ":GPIO%d input %d\n", pin, val_down);

	if (val_up && val_down)
		ret = 1;
	else if (!val_up && !val_down)
		ret = 0;
	else if (val_up && !val_down)
		ret = 2;
	else {
		pr_notice(FUN_3STATE ":GPIO%d pull HW is abnormal\n", pin);
		ret = -EINVAL;
	}

out:
	/* restore pullsel */
	hw->soc->bias_set_combo(hw, desc, pullup, pullen);

	return ret;
}

static int mtk_hw_set_value_wrap(struct mtk_pinctrl *hw, unsigned int gpio,
	int value, int field)
{
	const struct mtk_pin_desc *desc;

	if (gpio > hw->soc->npins)
		return -EINVAL;

	desc = (const struct mtk_pin_desc *)&hw->soc->pins[gpio];

	return mtk_hw_set_value(hw, desc, field, value);
}

#define mtk_pctrl_set_pinmux(hw, gpio, val)		\
	mtk_hw_set_value_wrap(hw, gpio, val, PINCTRL_PIN_REG_MODE)

/* MTK HW use 0 as input, 1 for output
 * This interface is for set direct register value,
 * so don't reverse
 */
#define mtk_pctrl_set_direction(hw, gpio, val)		\
	mtk_hw_set_value_wrap(hw, gpio, val, PINCTRL_PIN_REG_DIR)

#define mtk_pctrl_set_out(hw, gpio, val)		\
	mtk_hw_set_value_wrap(hw, gpio, val, PINCTRL_PIN_REG_DO)

#define mtk_pctrl_set_smt(hw, gpio, val)		\
	mtk_hw_set_value_wrap(hw, gpio, val, PINCTRL_PIN_REG_SMT)

#define mtk_pctrl_set_ies(hw, gpio, val)		\
	mtk_hw_set_value_wrap(hw, gpio, val, PINCTRL_PIN_REG_IES)

static ssize_t mtk_gpio_show_pin(struct device *dev,
	struct device_attribute *attr, char *buf)
{
	int len = 0;
	unsigned int bufLen = PAGE_SIZE;
	unsigned int i = 0;
	struct mtk_pinctrl *hw = dev_get_drvdata(dev);
	struct gpio_chip *chip;

	if (!hw || !buf) {
		pr_debug("[pinctrl] Err: NULL pointer!\n");
		return len;
	}

	chip = &hw->chip;

	len += snprintf(buf+len, bufLen-len,
		"pins base: %d\n", chip->base);
	len += snprintf(buf+len, bufLen-len,
		"PIN: (MODE)(DIR)(DOUT)(DIN)(DRIVE)(SMT)(IES)(PULL_EN)(PULL_SEL)(R1 R0)\n");

	for (i = 0; i < chip->ngpio; i++) {
		if (len > (bufLen - 96)) {
			pr_debug("[pinctrl]err:%d exceed to max size %d\n",
				len, (bufLen - 96));
			break;
		}
		len += mtk_pctrl_show_one_pin(hw, i, buf + len, bufLen - len);
	}

	return len;
}

void gpio_dump_regs_range(int start, int end)
{
	struct gpio_chip *chip = NULL;
	struct mtk_pinctrl *hw;
	char buf[96];
	int i;

	if (!g_hw)
		mtk_gpio_find_mtk_pinctrl_dev();
	if (!g_hw)
		return;

	hw = g_hw;
	chip = &hw->chip;

	if (start < 0) {
		start = 0;
		end = chip->ngpio - 1;
	}
	if (end < 0)
		end = chip->ngpio - 1;
	if (end > chip->ngpio - 1)
		end = chip->ngpio - 1;

	pr_notice("PIN: (MODE)(DIR)(DOUT)(DIN)(DRIVE)(SMT)(IES)(PULL_EN)(PULL_SEL)(R1 R0)\n");

	for (i = start; i < end; i++) {
		(void)mtk_pctrl_show_one_pin(hw, i, buf, 96);
		pr_notice("%s", buf);
	}
}
EXPORT_SYMBOL_GPL(gpio_dump_regs_range);

void gpio_dump_regs(void)
{
	gpio_dump_regs_range(-1, -1);
}

static ssize_t mtk_gpio_store_pin(struct device *dev,
	struct device_attribute *attr, const char *buf, size_t count)
{
	int i, gpio, val, val2, pullup = 0, pullen = 0;
	int vals[12];
	char attrs[12];
	struct mtk_pinctrl *hw = dev_get_drvdata(dev);
	const struct mtk_pin_desc *desc;
	struct gpio_chip *chip;
	int r1r0_en[4] = {MTK_PUPD_SET_R1R0_00, MTK_PUPD_SET_R1R0_01,
			  MTK_PUPD_SET_R1R0_10, MTK_PUPD_SET_R1R0_11};

	if (!hw || !hw->soc) {
		pr_notice("[pinctrl]cannot find %s device\n",
			pinctrl_paris_modname);
		return count;
	}

	chip = &hw->chip;

	if (!strncmp(buf, "mode", 4)
		&& (sscanf(buf+4, "%d %d", &gpio, &val) == 2)) {
		mtk_pctrl_set_pinmux(hw, gpio, val);
	} else if (!strncmp(buf, "dir", 3)
		&& (sscanf(buf+3, "%d %d", &gpio, &val) == 2)) {
		mtk_pctrl_set_direction(hw, gpio, val);
	} else if (!strncmp(buf, "out", 3)
		&& (sscanf(buf+3, "%d %d", &gpio, &val) == 2)) {
		mtk_pctrl_set_direction(hw, gpio, 1);
		/* mtk_gpio_set(chip, gpio, val); */
		mtk_pctrl_set_out(hw, gpio, val);
	} else if (!strncmp(buf, "pullen", 6)
		&& (sscanf(buf+6, "%d %d", &gpio, &val) == 2)) {
		if (gpio < 0 || gpio > hw->soc->npins) {
			pr_notice("invalid pin number\n");
			goto out;
		}
		desc = (const struct mtk_pin_desc *)&hw->soc->pins[gpio];
		if (!hw->soc->bias_get_combo || !hw->soc->bias_set_combo)
			goto no_bias_combo_out;
		hw->soc->bias_get_combo(hw, desc, &pullup, &pullen);
		if (pullen < MTK_PUPD_SET_R1R0_00) {
			pullen = !!val;
		} else {
			if (val < 0)
				val = 0;
			else if (val > 3)
				val = 3;
			pullen = r1r0_en[val];
		}
		hw->soc->bias_set_combo(hw, desc, pullup, pullen);
	} else if ((!strncmp(buf, "pullsel", 7))
		&& (sscanf(buf+7, "%d %d", &gpio, &val) == 2)) {
		if (gpio < 0 || gpio > hw->soc->npins) {
			pr_notice("invalid pin number\n");
			goto out;
		}
		desc = (const struct mtk_pin_desc *)&hw->soc->pins[gpio];
		if (!hw->soc->bias_get_combo || !hw->soc->bias_set_combo)
			goto no_bias_combo_out;
		hw->soc->bias_get_combo(hw, desc, &pullup, &pullen);
		hw->soc->bias_set_combo(hw, desc, !!val, pullen);
	} else if ((!strncmp(buf, "ies", 3))
		&& (sscanf(buf+3, "%d %d", &gpio, &val) == 2)) {
		mtk_pctrl_set_ies(hw, gpio, val);
	} else if ((!strncmp(buf, "smt", 3))
		&& (sscanf(buf+3, "%d %d", &gpio, &val) == 2)) {
		mtk_pctrl_set_smt(hw, gpio, val);
	} else if ((!strncmp(buf, "driving", 7))
		&& (sscanf(buf+7, "%d %d", &gpio, &val) == 2)) {
		if (gpio < 0 || gpio > hw->soc->npins) {
			pr_notice("invalid pin number\n");
			goto out;
		}
		desc = (const struct mtk_pin_desc *)&hw->soc->pins[gpio];
		hw->soc->drive_set(hw, desc, val);
	} else if ((!strncmp(buf, "r1r0", 4))
		&& (sscanf(buf+4, "%d %d %d", &gpio, &val, &val2) == 3)) {
		if (gpio < 0 || gpio > hw->soc->npins) {
			pr_notice("invalid pin number\n");
			goto out;
		}
		desc = (const struct mtk_pin_desc *)&hw->soc->pins[gpio];
		if (!hw->soc->bias_get_combo || !hw->soc->bias_set_combo)
			goto no_bias_combo_out;
		hw->soc->bias_get_combo(hw, desc, &pullup, &pullen);
		pullen = r1r0_en[(((!!val) << 1) + !!val2)];
		hw->soc->bias_set_combo(hw, desc, pullup, pullen);
	} else if (!strncmp(buf, "set", 3)) {
		val = sscanf(buf+3, "%d %c%c%c%c%c%c%c%c%c%c %c%c", &gpio,
			&attrs[0], &attrs[1], &attrs[2], &attrs[3],
			&attrs[4], &attrs[5], &attrs[6], &attrs[7],
			&attrs[8], &attrs[9], &attrs[10], &attrs[11]);
		if (val <= 0 || val > 13) {
			pr_notice("invalid input count %d\n", val);
			goto out;
		}
		if (!hw->soc->bias_get_combo || !hw->soc->bias_set_combo)
			goto no_bias_combo_out;
		for (i = 0; i < ARRAY_SIZE(attrs); i++) {
			if ((attrs[i] >= '0') && (attrs[i] <= '9'))
				vals[i] = attrs[i] - '0';
			else
				vals[i] = 0;
		}
		if (gpio < 0) {
			pr_notice("invalid pin number\n");
			goto out;
		}
		desc = (const struct mtk_pin_desc *)&hw->soc->pins[gpio];
		/* MODE */
		mtk_pctrl_set_pinmux(hw, gpio, vals[0]);
		/* DIR */
		mtk_pctrl_set_direction(hw, gpio, !!vals[1]);
		/* DOUT */
		if (vals[1])
			/*mtk_gpio_set(chip, gpio, !!vals[2]); */
			mtk_pctrl_set_out(hw, gpio, !!vals[2]);
		/* DRIVING */
		desc = (const struct mtk_pin_desc *)&hw->soc->pins[gpio];
		hw->soc->drive_set(hw, desc, vals[4]*10 + vals[5]);
		/* SMT */
		mtk_pctrl_set_smt(hw, gpio, vals[6]);
		/* IES */
		mtk_pctrl_set_ies(hw, gpio, vals[7]);
		/* PULL */
		hw->soc->bias_get_combo(hw, desc, &pullup, &pullen);
		if (pullen < MTK_PUPD_SET_R1R0_00) {
			hw->soc->bias_set_combo(hw, desc, !!vals[9],
				!!vals[8]);
		} else {
			pullen = r1r0_en[(((!!vals[10]) << 1) + !!vals[11])];
			hw->soc->bias_set_combo(hw, desc, !!vals[9],
				pullen);
		}
	}

out:
	return count;

no_bias_combo_out:
	pr_notice("[pinctrl]bias_set_combo/bias_get_combo not supported\n");
	return count;
}

static DEVICE_ATTR(mt_gpio, 0444, mtk_gpio_show_pin, mtk_gpio_store_pin);

static int mtk_gpio_create_attr(void)
{
	struct mtk_pinctrl *hw = NULL;
	struct gpio_desc *gdesc;
	unsigned int pin = ARCH_NR_GPIOS - 1;
	int err = 0;

	do {
		gdesc = gpio_to_desc(pin);
		if (!gdesc)
			break;
		if (!strncmp(pinctrl_paris_modname,
				gdesc->gdev->chip->label,
				strlen(pinctrl_paris_modname))) {
			hw = gpiochip_get_data(gdesc->gdev->chip);
			if (!hw || !hw->soc || !hw->dev) {
				pr_notice("invalid gpio chip\n");
				return -EINVAL;
			}

			err = device_create_file(hw->dev, &dev_attr_mt_gpio);
			if (err) {
				pr_notice("[pinctrl]error create mtk_gpio\n");
				break;
			}
		}

		pin = (pin + 1) - gdesc->gdev->chip->base;
	} while (pin > 0);

	return err;
}
static int __init pinctrl_mtk_debug_v2_init(void)
{
	return mtk_gpio_create_attr();
}

late_initcall(pinctrl_mtk_debug_v2_init);

MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("MediaTek Pinctrl DEBUG Driver");