/*
 * Copyright (c) 2016-2017, The Linux Foundation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 and
 * only 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.
 */

#include <linux/gpio.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/pinctrl/pinconf-generic.h>
#include <linux/pinctrl/pinconf.h>
#include <linux/pinctrl/pinmux.h>
#include <linux/platform_device.h>
#include <linux/qdsp6v2/audio_notifier.h>
#include <linux/slab.h>
#include <linux/types.h>

#include "../core.h"
#include "../pinctrl-utils.h"

#define LPI_ADDRESS_SIZE			0xC000

#define LPI_GPIO_REG_VAL_CTL			0x00
#define LPI_GPIO_REG_DIR_CTL			0x04

#define LPI_GPIO_REG_PULL_SHIFT			0x0
#define LPI_GPIO_REG_PULL_MASK			0x3

#define LPI_GPIO_REG_FUNCTION_SHIFT		0x2
#define LPI_GPIO_REG_FUNCTION_MASK		0x3C

#define LPI_GPIO_REG_OUT_STRENGTH_SHIFT		0x6
#define LPI_GPIO_REG_OUT_STRENGTH_MASK		0x1C0

#define LPI_GPIO_REG_OE_SHIFT			0x9
#define LPI_GPIO_REG_OE_MASK			0x200

#define LPI_GPIO_REG_DIR_SHIFT			0x1
#define LPI_GPIO_REG_DIR_MASK			0x2

#define LPI_GPIO_BIAS_DISABLE			0x0
#define LPI_GPIO_PULL_DOWN			0x1
#define LPI_GPIO_KEEPER				0x2
#define LPI_GPIO_PULL_UP			0x3

#define LPI_GPIO_FUNC_GPIO			"gpio"
#define LPI_GPIO_FUNC_FUNC1			"func1"
#define LPI_GPIO_FUNC_FUNC2			"func2"
#define LPI_GPIO_FUNC_FUNC3			"func3"
#define LPI_GPIO_FUNC_FUNC4			"func4"
#define LPI_GPIO_FUNC_FUNC5			"func5"

static bool lpi_dev_up;
/* The index of each function in lpi_gpio_functions[] array */
enum lpi_gpio_func_index {
	LPI_GPIO_FUNC_INDEX_GPIO	= 0x00,
	LPI_GPIO_FUNC_INDEX_FUNC1	= 0x01,
	LPI_GPIO_FUNC_INDEX_FUNC2	= 0x02,
	LPI_GPIO_FUNC_INDEX_FUNC3	= 0x03,
	LPI_GPIO_FUNC_INDEX_FUNC4	= 0x04,
	LPI_GPIO_FUNC_INDEX_FUNC5	= 0x05,
};

/**
 * struct lpi_gpio_pad - keep current GPIO settings
 * @offset: Nth GPIO in supported GPIOs.
 * @output_enabled: Set to true if GPIO output logic is enabled.
 * @value: value of a pin
 * @base: Address base of LPI GPIO PAD.
 * @pullup: Constant current which flow through GPIO output buffer.
 * @strength: No, Low, Medium, High
 * @function: See lpi_gpio_functions[]
 */
struct lpi_gpio_pad {
	u16		offset;
	bool		output_enabled;
	bool		value;
	char __iomem	*base;
	unsigned int	pullup;
	unsigned int	strength;
	unsigned int	function;
};

struct lpi_gpio_state {
	struct device	*dev;
	struct pinctrl_dev *ctrl;
	struct gpio_chip chip;
	char __iomem	*base;
};

static const char *const lpi_gpio_groups[] = {
	"gpio0", "gpio1", "gpio2", "gpio3", "gpio4", "gpio5", "gpio6", "gpio7",
	"gpio8", "gpio9", "gpio10", "gpio11", "gpio12", "gpio13", "gpio14",
	"gpio15", "gpio16", "gpio17", "gpio18", "gpio19", "gpio20", "gpio21",
	"gpio22", "gpio23", "gpio24", "gpio25", "gpio26", "gpio27", "gpio28",
	"gpio29", "gpio30", "gpio31",
};

static const u32 lpi_offset[] = {
	0x00000000,
	0x00001000,
	0x00002000,
	0x00002010,
	0x00003000,
	0x00003010,
	0x00004000,
	0x00004010,
	0x00005000,
	0x00005010,
	0x00005020,
	0x00005030,
	0x00006000,
	0x00006010,
	0x00007000,
	0x00007010,
	0x00005040,
	0x00005050,
	0x00008000,
	0x00008010,
	0x00008020,
	0x00008030,
	0x00008040,
	0x00008050,
	0x00008060,
	0x00008070,
	0x00009000,
	0x00009010,
	0x0000A000,
	0x0000A010,
	0x0000B000,
	0x0000B010,
};

static const char *const lpi_gpio_functions[] = {
	[LPI_GPIO_FUNC_INDEX_GPIO]	= LPI_GPIO_FUNC_GPIO,
	[LPI_GPIO_FUNC_INDEX_FUNC1]	= LPI_GPIO_FUNC_FUNC1,
	[LPI_GPIO_FUNC_INDEX_FUNC2]	= LPI_GPIO_FUNC_FUNC2,
	[LPI_GPIO_FUNC_INDEX_FUNC3]	= LPI_GPIO_FUNC_FUNC3,
	[LPI_GPIO_FUNC_INDEX_FUNC4]	= LPI_GPIO_FUNC_FUNC4,
	[LPI_GPIO_FUNC_INDEX_FUNC5]	= LPI_GPIO_FUNC_FUNC5,
};

static inline struct lpi_gpio_state *to_gpio_state(struct gpio_chip *chip)
{
	return container_of(chip, struct lpi_gpio_state, chip);
};

static int lpi_gpio_read(struct lpi_gpio_pad *pad, unsigned int addr)
{
	int ret;

	if (!lpi_dev_up) {
		pr_err_ratelimited("%s: ADSP is down due to SSR, return\n",
				   __func__);
		return 0;
	}

	ret = ioread32(pad->base + pad->offset + addr);
	if (ret < 0)
		pr_err("%s: read 0x%x failed\n", __func__, addr);

	return ret;
}

static int lpi_gpio_write(struct lpi_gpio_pad *pad, unsigned int addr,
			  unsigned int val)
{
	if (!lpi_dev_up) {
		pr_err_ratelimited("%s: ADSP is down due to SSR, return\n",
				   __func__);
		return 0;
	}

	iowrite32(val, pad->base + pad->offset + addr);
	return 0;
}

static int lpi_gpio_get_groups_count(struct pinctrl_dev *pctldev)
{
	/* Every PIN is a group */
	return pctldev->desc->npins;
}

static const char *lpi_gpio_get_group_name(struct pinctrl_dev *pctldev,
					   unsigned pin)
{
	return pctldev->desc->pins[pin].name;
}

static int lpi_gpio_get_group_pins(struct pinctrl_dev *pctldev, unsigned pin,
				   const unsigned **pins, unsigned *num_pins)
{
	*pins = &pctldev->desc->pins[pin].number;
	*num_pins = 1;
	return 0;
}

static const struct pinctrl_ops lpi_gpio_pinctrl_ops = {
	.get_groups_count	= lpi_gpio_get_groups_count,
	.get_group_name		= lpi_gpio_get_group_name,
	.get_group_pins		= lpi_gpio_get_group_pins,
	.dt_node_to_map		= pinconf_generic_dt_node_to_map_group,
	.dt_free_map		= pinctrl_utils_dt_free_map,
};

static int lpi_gpio_get_functions_count(struct pinctrl_dev *pctldev)
{
	return ARRAY_SIZE(lpi_gpio_functions);
}

static const char *lpi_gpio_get_function_name(struct pinctrl_dev *pctldev,
					      unsigned function)
{
	return lpi_gpio_functions[function];
}

static int lpi_gpio_get_function_groups(struct pinctrl_dev *pctldev,
					unsigned function,
					const char *const **groups,
					unsigned *const num_qgroups)
{
	*groups = lpi_gpio_groups;
	*num_qgroups = pctldev->desc->npins;
	return 0;
}

static int lpi_gpio_set_mux(struct pinctrl_dev *pctldev, unsigned function,
			    unsigned pin)
{
	struct lpi_gpio_pad *pad;
	unsigned int val;

	pad = pctldev->desc->pins[pin].drv_data;

	pad->function = function;

	val = lpi_gpio_read(pad, LPI_GPIO_REG_VAL_CTL);
	val &= ~(LPI_GPIO_REG_FUNCTION_MASK);
	val |= pad->function << LPI_GPIO_REG_FUNCTION_SHIFT;
	lpi_gpio_write(pad, LPI_GPIO_REG_VAL_CTL, val);
	return 0;
}

static const struct pinmux_ops lpi_gpio_pinmux_ops = {
	.get_functions_count	= lpi_gpio_get_functions_count,
	.get_function_name	= lpi_gpio_get_function_name,
	.get_function_groups	= lpi_gpio_get_function_groups,
	.set_mux		= lpi_gpio_set_mux,
};

static int lpi_config_get(struct pinctrl_dev *pctldev,
			  unsigned int pin, unsigned long *config)
{
	unsigned param = pinconf_to_config_param(*config);
	struct lpi_gpio_pad *pad;
	unsigned arg;

	pad = pctldev->desc->pins[pin].drv_data;

	switch (param) {
	case PIN_CONFIG_BIAS_DISABLE:
		arg = pad->pullup = LPI_GPIO_BIAS_DISABLE;
		break;
	case PIN_CONFIG_BIAS_PULL_DOWN:
		arg = pad->pullup == LPI_GPIO_PULL_DOWN;
		break;
	case PIN_CONFIG_BIAS_BUS_HOLD:
		arg = pad->pullup = LPI_GPIO_KEEPER;
		break;
	case PIN_CONFIG_BIAS_PULL_UP:
		arg = pad->pullup == LPI_GPIO_PULL_UP;
		break;
	case PIN_CONFIG_INPUT_ENABLE:
	case PIN_CONFIG_OUTPUT:
		arg = pad->output_enabled;
		break;
	default:
		return -EINVAL;
	}

	*config = pinconf_to_config_packed(param, arg);
	return 0;
}

static unsigned lpi_drive_to_regval(u32 arg)
{
	return (arg/2 - 1);
}

static int lpi_config_set(struct pinctrl_dev *pctldev, unsigned int pin,
			  unsigned long *configs, unsigned nconfs)
{
	struct lpi_gpio_pad *pad;
	unsigned param, arg;
	int i, ret = 0, val;

	pad = pctldev->desc->pins[pin].drv_data;

	for (i = 0; i < nconfs; i++) {
		param = pinconf_to_config_param(configs[i]);
		arg = pinconf_to_config_argument(configs[i]);

		dev_dbg(pctldev->dev, "%s: param: %d arg: %d pin: %d\n",
			__func__, param, arg, pin);

		switch (param) {
		case PIN_CONFIG_BIAS_DISABLE:
			pad->pullup = LPI_GPIO_BIAS_DISABLE;
			break;
		case PIN_CONFIG_BIAS_PULL_DOWN:
			pad->pullup = LPI_GPIO_PULL_DOWN;
			break;
		case PIN_CONFIG_BIAS_BUS_HOLD:
			pad->pullup = LPI_GPIO_KEEPER;
			break;
		case PIN_CONFIG_BIAS_PULL_UP:
			pad->pullup = LPI_GPIO_PULL_UP;
			break;
		case PIN_CONFIG_INPUT_ENABLE:
			pad->output_enabled = false;
			break;
		case PIN_CONFIG_OUTPUT:
			pad->output_enabled = true;
			pad->value = arg;
			break;
		case PIN_CONFIG_DRIVE_STRENGTH:
			pad->strength = arg;
			break;
		default:
			ret = -EINVAL;
			goto done;
		}
	}

	val = lpi_gpio_read(pad, LPI_GPIO_REG_VAL_CTL);
	val &= ~(LPI_GPIO_REG_PULL_MASK | LPI_GPIO_REG_OUT_STRENGTH_MASK |
		 LPI_GPIO_REG_OE_MASK);
	val |= pad->pullup << LPI_GPIO_REG_PULL_SHIFT;
	val |= lpi_drive_to_regval(pad->strength) <<
		LPI_GPIO_REG_OUT_STRENGTH_SHIFT;
	if (pad->output_enabled)
		val |= pad->value << LPI_GPIO_REG_OE_SHIFT;

	lpi_gpio_write(pad, LPI_GPIO_REG_VAL_CTL, val);
	lpi_gpio_write(pad, LPI_GPIO_REG_DIR_CTL,
		       pad->output_enabled << LPI_GPIO_REG_DIR_SHIFT);
done:
	return ret;
}

static const struct pinconf_ops lpi_gpio_pinconf_ops = {
	.is_generic			= true,
	.pin_config_group_get		= lpi_config_get,
	.pin_config_group_set		= lpi_config_set,
};

static int lpi_gpio_direction_input(struct gpio_chip *chip, unsigned pin)
{
	struct lpi_gpio_state *state = to_gpio_state(chip);
	unsigned long config;

	config = pinconf_to_config_packed(PIN_CONFIG_INPUT_ENABLE, 1);

	return lpi_config_set(state->ctrl, pin, &config, 1);
}

static int lpi_gpio_direction_output(struct gpio_chip *chip,
				     unsigned pin, int val)
{
	struct lpi_gpio_state *state = to_gpio_state(chip);
	unsigned long config;

	config = pinconf_to_config_packed(PIN_CONFIG_OUTPUT, val);

	return lpi_config_set(state->ctrl, pin, &config, 1);
}

static int lpi_gpio_get(struct gpio_chip *chip, unsigned pin)
{
	struct lpi_gpio_state *state = to_gpio_state(chip);
	struct lpi_gpio_pad *pad;
	int value;

	pad = state->ctrl->desc->pins[pin].drv_data;

	value = lpi_gpio_read(pad, LPI_GPIO_REG_VAL_CTL);
	return value;
}

static void lpi_gpio_set(struct gpio_chip *chip, unsigned pin, int value)
{
	struct lpi_gpio_state *state = to_gpio_state(chip);
	unsigned long config;

	config = pinconf_to_config_packed(PIN_CONFIG_OUTPUT, value);

	lpi_config_set(state->ctrl, pin, &config, 1);
}

static int lpi_notifier_service_cb(struct notifier_block *this,
				   unsigned long opcode, void *ptr)
{
	pr_debug("%s: Service opcode 0x%lx\n", __func__, opcode);

	switch (opcode) {
	case AUDIO_NOTIFIER_SERVICE_DOWN:
		lpi_dev_up = false;
		break;
	case AUDIO_NOTIFIER_SERVICE_UP:
		lpi_dev_up = true;
		break;
	default:
		break;
	}
	return NOTIFY_OK;
}

static struct notifier_block service_nb = {
	.notifier_call  = lpi_notifier_service_cb,
	.priority = -INT_MAX,
};

#ifdef CONFIG_DEBUG_FS
#include <linux/seq_file.h>

static unsigned lpi_regval_to_drive(u32 val)
{
	return (val + 1) * 2;
}

static void lpi_gpio_dbg_show_one(struct seq_file *s,
				  struct pinctrl_dev *pctldev,
				  struct gpio_chip *chip,
				  unsigned offset,
				  unsigned gpio)
{
	struct pinctrl_pin_desc pindesc;
	struct lpi_gpio_pad *pad;
	unsigned func;
	int is_out;
	int drive;
	int pull;
	u32 ctl_reg;

	static const char * const pulls[] = {
		"no pull",
		"pull down",
		"keeper",
		"pull up"
	};

	pindesc = pctldev->desc->pins[offset];
	pad = pctldev->desc->pins[offset].drv_data;
	ctl_reg = lpi_gpio_read(pad, LPI_GPIO_REG_DIR_CTL);
	is_out = (ctl_reg & LPI_GPIO_REG_DIR_MASK) >> LPI_GPIO_REG_DIR_SHIFT;
	ctl_reg = lpi_gpio_read(pad, LPI_GPIO_REG_VAL_CTL);

	func = (ctl_reg & LPI_GPIO_REG_FUNCTION_MASK) >>
		LPI_GPIO_REG_FUNCTION_SHIFT;
	drive = (ctl_reg & LPI_GPIO_REG_OUT_STRENGTH_MASK) >>
		 LPI_GPIO_REG_OUT_STRENGTH_SHIFT;
	pull = (ctl_reg & LPI_GPIO_REG_PULL_MASK) >> LPI_GPIO_REG_PULL_SHIFT;

	seq_printf(s, " %-8s: %-3s %d",
		   pindesc.name, is_out ? "out" : "in", func);
	seq_printf(s, " %dmA", lpi_regval_to_drive(drive));
	seq_printf(s, " %s", pulls[pull]);
}

static void lpi_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
{
	unsigned gpio = chip->base;
	unsigned i;

	for (i = 0; i < chip->ngpio; i++, gpio++) {
		lpi_gpio_dbg_show_one(s, NULL, chip, i, gpio);
		seq_puts(s, "\n");
	}
}

#else
#define lpi_gpio_dbg_show NULL
#endif

static const struct gpio_chip lpi_gpio_template = {
	.direction_input	= lpi_gpio_direction_input,
	.direction_output	= lpi_gpio_direction_output,
	.get			= lpi_gpio_get,
	.set			= lpi_gpio_set,
	.request		= gpiochip_generic_request,
	.free			= gpiochip_generic_free,
	.dbg_show		= lpi_gpio_dbg_show,
};

static int lpi_pinctrl_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct pinctrl_pin_desc *pindesc;
	struct pinctrl_desc *pctrldesc;
	struct lpi_gpio_pad *pad, *pads;
	struct lpi_gpio_state *state;
	int ret, npins, i;
	char __iomem *lpi_base;
	u32 reg;

	ret = of_property_read_u32(dev->of_node, "reg", &reg);
	if (ret < 0) {
		dev_err(dev, "missing base address\n");
		return ret;
	}

	ret = of_property_read_u32(dev->of_node, "qcom,num-gpios", &npins);
	if (ret < 0)
		return ret;

	WARN_ON(npins > ARRAY_SIZE(lpi_gpio_groups));

	state = devm_kzalloc(dev, sizeof(*state), GFP_KERNEL);
	if (!state)
		return -ENOMEM;

	platform_set_drvdata(pdev, state);

	state->dev = &pdev->dev;

	pindesc = devm_kcalloc(dev, npins, sizeof(*pindesc), GFP_KERNEL);
	if (!pindesc)
		return -ENOMEM;

	pads = devm_kcalloc(dev, npins, sizeof(*pads), GFP_KERNEL);
	if (!pads)
		return -ENOMEM;

	pctrldesc = devm_kzalloc(dev, sizeof(*pctrldesc), GFP_KERNEL);
	if (!pctrldesc)
		return -ENOMEM;

	pctrldesc->pctlops = &lpi_gpio_pinctrl_ops;
	pctrldesc->pmxops = &lpi_gpio_pinmux_ops;
	pctrldesc->confops = &lpi_gpio_pinconf_ops;
	pctrldesc->owner = THIS_MODULE;
	pctrldesc->name = dev_name(dev);
	pctrldesc->pins = pindesc;
	pctrldesc->npins = npins;

	lpi_base = ioremap(reg, LPI_ADDRESS_SIZE);
	if (lpi_base == NULL) {
		dev_err(state->dev, "%s ioremap failed\n", __func__);
		return -ENOMEM;
	}
	state->base = lpi_base;
	for (i = 0; i < npins; i++, pindesc++) {
		pad = &pads[i];
		pindesc->drv_data = pad;
		pindesc->number = i;
		pindesc->name = lpi_gpio_groups[i];

		pad->base = lpi_base;
		pad->offset = lpi_offset[i];
	}

	state->chip = lpi_gpio_template;
	state->chip.dev = dev;
	state->chip.base = -1;
	state->chip.ngpio = npins;
	state->chip.label = dev_name(dev);
	state->chip.of_gpio_n_cells = 2;
	state->chip.can_sleep = false;

	state->ctrl = pinctrl_register(pctrldesc, dev, state);
	if (IS_ERR(state->ctrl)) {
		iounmap(state->base);
		return PTR_ERR(state->ctrl);
	}

	ret = gpiochip_add(&state->chip);
	if (ret) {
		dev_err(state->dev, "can't add gpio chip\n");
		goto err_chip;
	}

	ret = gpiochip_add_pin_range(&state->chip, dev_name(dev), 0, 0, npins);
	if (ret) {
		dev_err(dev, "failed to add pin range\n");
		goto err_range;
	}

	lpi_dev_up = true;
	ret = audio_notifier_register("lpi_tlmm", AUDIO_NOTIFIER_ADSP_DOMAIN,
				      &service_nb);
	if (ret < 0) {
		pr_err("%s: Audio notifier register failed ret = %d\n",
			__func__, ret);
		goto err_range;
	}

	return 0;

err_range:
	gpiochip_remove(&state->chip);
err_chip:
	pinctrl_unregister(state->ctrl);
	iounmap(state->base);
	return ret;
}

static int lpi_pinctrl_remove(struct platform_device *pdev)
{
	struct lpi_gpio_state *state = platform_get_drvdata(pdev);

	iounmap(state->base);
	gpiochip_remove(&state->chip);
	pinctrl_unregister(state->ctrl);
	return 0;
}

static const struct of_device_id lpi_pinctrl_of_match[] = {
	{ .compatible = "qcom,lpi-pinctrl" }, /* Generic */
	{ },
};

MODULE_DEVICE_TABLE(of, lpi_pinctrl_of_match);

static struct platform_driver lpi_pinctrl_driver = {
	.driver = {
		   .name = "qcom-lpi-pinctrl",
		   .of_match_table = lpi_pinctrl_of_match,
	},
	.probe = lpi_pinctrl_probe,
	.remove = lpi_pinctrl_remove,
};

module_platform_driver(lpi_pinctrl_driver);

MODULE_DESCRIPTION("QTI LPI GPIO pin control driver");
MODULE_LICENSE("GPL v2");