// SPDX-License-Identifier: GPL-2.0+
/*
 * Driver for BCM6358 GPIO unit (pinctrl + GPIO)
 *
 * Copyright (C) 2021 Álvaro Fernández Rojas <noltari@gmail.com>
 * Copyright (C) 2016 Jonas Gorski <jonas.gorski@gmail.com>
 */

#include <linux/bits.h>
#include <linux/gpio/driver.h>
#include <linux/kernel.h>
#include <linux/of.h>
#include <linux/pinctrl/pinmux.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>

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

#include "pinctrl-bcm63xx.h"

#define BCM6358_NUM_GPIOS		40

#define BCM6358_MODE_REG		0x18
#define  BCM6358_MODE_MUX_NONE		0
#define  BCM6358_MODE_MUX_EBI_CS	BIT(5)
#define  BCM6358_MODE_MUX_UART1		BIT(6)
#define  BCM6358_MODE_MUX_SPI_CS	BIT(7)
#define  BCM6358_MODE_MUX_ASYNC_MODEM	BIT(8)
#define  BCM6358_MODE_MUX_LEGACY_LED	BIT(9)
#define  BCM6358_MODE_MUX_SERIAL_LED	BIT(10)
#define  BCM6358_MODE_MUX_LED		BIT(11)
#define  BCM6358_MODE_MUX_UTOPIA	BIT(12)
#define  BCM6358_MODE_MUX_CLKRST	BIT(13)
#define  BCM6358_MODE_MUX_PWM_SYN_CLK	BIT(14)
#define  BCM6358_MODE_MUX_SYS_IRQ	BIT(15)

struct bcm6358_pingroup {
	const char *name;
	const unsigned * const pins;
	const unsigned num_pins;

	const uint16_t mode_val;

	/* non-GPIO function muxes require the gpio direction to be set */
	const uint16_t direction;
};

struct bcm6358_function {
	const char *name;
	const char * const *groups;
	const unsigned num_groups;
};

struct bcm6358_priv {
	struct regmap_field *overlays;
};

#define BCM6358_GPIO_PIN(a, b, bit1, bit2, bit3)		\
	{							\
		.number = a,					\
		.name = b,					\
		.drv_data = (void *)(BCM6358_MODE_MUX_##bit1 |	\
				     BCM6358_MODE_MUX_##bit2 |	\
				     BCM6358_MODE_MUX_##bit3),	\
	}

static const struct pinctrl_pin_desc bcm6358_pins[] = {
	BCM6358_GPIO_PIN(0, "gpio0", LED, NONE, NONE),
	BCM6358_GPIO_PIN(1, "gpio1", LED, NONE, NONE),
	BCM6358_GPIO_PIN(2, "gpio2", LED, NONE, NONE),
	BCM6358_GPIO_PIN(3, "gpio3", LED, NONE, NONE),
	PINCTRL_PIN(4, "gpio4"),
	BCM6358_GPIO_PIN(5, "gpio5", SYS_IRQ, NONE, NONE),
	BCM6358_GPIO_PIN(6, "gpio6", SERIAL_LED, NONE, NONE),
	BCM6358_GPIO_PIN(7, "gpio7", SERIAL_LED, NONE, NONE),
	BCM6358_GPIO_PIN(8, "gpio8", PWM_SYN_CLK, NONE, NONE),
	BCM6358_GPIO_PIN(9, "gpio09", LEGACY_LED, NONE, NONE),
	BCM6358_GPIO_PIN(10, "gpio10", LEGACY_LED, NONE, NONE),
	BCM6358_GPIO_PIN(11, "gpio11", LEGACY_LED, NONE, NONE),
	BCM6358_GPIO_PIN(12, "gpio12", LEGACY_LED, ASYNC_MODEM, UTOPIA),
	BCM6358_GPIO_PIN(13, "gpio13", LEGACY_LED, ASYNC_MODEM, UTOPIA),
	BCM6358_GPIO_PIN(14, "gpio14", LEGACY_LED, ASYNC_MODEM, UTOPIA),
	BCM6358_GPIO_PIN(15, "gpio15", LEGACY_LED, ASYNC_MODEM, UTOPIA),
	PINCTRL_PIN(16, "gpio16"),
	PINCTRL_PIN(17, "gpio17"),
	PINCTRL_PIN(18, "gpio18"),
	PINCTRL_PIN(19, "gpio19"),
	PINCTRL_PIN(20, "gpio20"),
	PINCTRL_PIN(21, "gpio21"),
	BCM6358_GPIO_PIN(22, "gpio22", UTOPIA, NONE, NONE),
	BCM6358_GPIO_PIN(23, "gpio23", UTOPIA, NONE, NONE),
	BCM6358_GPIO_PIN(24, "gpio24", UTOPIA, NONE, NONE),
	BCM6358_GPIO_PIN(25, "gpio25", UTOPIA, NONE, NONE),
	BCM6358_GPIO_PIN(26, "gpio26", UTOPIA, NONE, NONE),
	BCM6358_GPIO_PIN(27, "gpio27", UTOPIA, NONE, NONE),
	BCM6358_GPIO_PIN(28, "gpio28", UTOPIA, UART1, NONE),
	BCM6358_GPIO_PIN(29, "gpio29", UTOPIA, UART1, NONE),
	BCM6358_GPIO_PIN(30, "gpio30", UTOPIA, UART1, EBI_CS),
	BCM6358_GPIO_PIN(31, "gpio31", UTOPIA, UART1, EBI_CS),
	BCM6358_GPIO_PIN(32, "gpio32", SPI_CS, NONE, NONE),
	BCM6358_GPIO_PIN(33, "gpio33", SPI_CS, NONE, NONE),
	PINCTRL_PIN(34, "gpio34"),
	PINCTRL_PIN(35, "gpio35"),
	PINCTRL_PIN(36, "gpio36"),
	PINCTRL_PIN(37, "gpio37"),
	PINCTRL_PIN(38, "gpio38"),
	PINCTRL_PIN(39, "gpio39"),
};

static unsigned ebi_cs_grp_pins[] = { 30, 31 };

static unsigned uart1_grp_pins[] = { 28, 29, 30, 31 };

static unsigned spi_cs_grp_pins[] = { 32, 33 };

static unsigned async_modem_grp_pins[] = { 12, 13, 14, 15 };

static unsigned serial_led_grp_pins[] = { 6, 7 };

static unsigned legacy_led_grp_pins[] = { 9, 10, 11, 12, 13, 14, 15 };

static unsigned led_grp_pins[] = { 0, 1, 2, 3 };

static unsigned utopia_grp_pins[] = {
	12, 13, 14, 15, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31,
};

static unsigned pwm_syn_clk_grp_pins[] = { 8 };

static unsigned sys_irq_grp_pins[] = { 5 };

#define BCM6358_GPIO_MUX_GROUP(n, bit, dir)			\
	{							\
		.name = #n,					\
		.pins = n##_pins,				\
		.num_pins = ARRAY_SIZE(n##_pins),		\
		.mode_val = BCM6358_MODE_MUX_##bit,		\
		.direction = dir,				\
	}

static const struct bcm6358_pingroup bcm6358_groups[] = {
	BCM6358_GPIO_MUX_GROUP(ebi_cs_grp, EBI_CS, 0x3),
	BCM6358_GPIO_MUX_GROUP(uart1_grp, UART1, 0x2),
	BCM6358_GPIO_MUX_GROUP(spi_cs_grp, SPI_CS, 0x6),
	BCM6358_GPIO_MUX_GROUP(async_modem_grp, ASYNC_MODEM, 0x6),
	BCM6358_GPIO_MUX_GROUP(legacy_led_grp, LEGACY_LED, 0x7f),
	BCM6358_GPIO_MUX_GROUP(serial_led_grp, SERIAL_LED, 0x3),
	BCM6358_GPIO_MUX_GROUP(led_grp, LED, 0xf),
	BCM6358_GPIO_MUX_GROUP(utopia_grp, UTOPIA, 0x000f),
	BCM6358_GPIO_MUX_GROUP(pwm_syn_clk_grp, PWM_SYN_CLK, 0x1),
	BCM6358_GPIO_MUX_GROUP(sys_irq_grp, SYS_IRQ, 0x1),
};

static const char * const ebi_cs_groups[] = {
	"ebi_cs_grp"
};

static const char * const uart1_groups[] = {
	"uart1_grp"
};

static const char * const spi_cs_2_3_groups[] = {
	"spi_cs_2_3_grp"
};

static const char * const async_modem_groups[] = {
	"async_modem_grp"
};

static const char * const legacy_led_groups[] = {
	"legacy_led_grp",
};

static const char * const serial_led_groups[] = {
	"serial_led_grp",
};

static const char * const led_groups[] = {
	"led_grp",
};

static const char * const clkrst_groups[] = {
	"clkrst_grp",
};

static const char * const pwm_syn_clk_groups[] = {
	"pwm_syn_clk_grp",
};

static const char * const sys_irq_groups[] = {
	"sys_irq_grp",
};

#define BCM6358_FUN(n)					\
	{						\
		.name = #n,				\
		.groups = n##_groups,			\
		.num_groups = ARRAY_SIZE(n##_groups),	\
	}

static const struct bcm6358_function bcm6358_funcs[] = {
	BCM6358_FUN(ebi_cs),
	BCM6358_FUN(uart1),
	BCM6358_FUN(spi_cs_2_3),
	BCM6358_FUN(async_modem),
	BCM6358_FUN(legacy_led),
	BCM6358_FUN(serial_led),
	BCM6358_FUN(led),
	BCM6358_FUN(clkrst),
	BCM6358_FUN(pwm_syn_clk),
	BCM6358_FUN(sys_irq),
};

static int bcm6358_pinctrl_get_group_count(struct pinctrl_dev *pctldev)
{
	return ARRAY_SIZE(bcm6358_groups);
}

static const char *bcm6358_pinctrl_get_group_name(struct pinctrl_dev *pctldev,
						  unsigned group)
{
	return bcm6358_groups[group].name;
}

static int bcm6358_pinctrl_get_group_pins(struct pinctrl_dev *pctldev,
					  unsigned group, const unsigned **pins,
					  unsigned *num_pins)
{
	*pins = bcm6358_groups[group].pins;
	*num_pins = bcm6358_groups[group].num_pins;

	return 0;
}

static int bcm6358_pinctrl_get_func_count(struct pinctrl_dev *pctldev)
{
	return ARRAY_SIZE(bcm6358_funcs);
}

static const char *bcm6358_pinctrl_get_func_name(struct pinctrl_dev *pctldev,
						 unsigned selector)
{
	return bcm6358_funcs[selector].name;
}

static int bcm6358_pinctrl_get_groups(struct pinctrl_dev *pctldev,
				      unsigned selector,
				      const char * const **groups,
				      unsigned * const num_groups)
{
	*groups = bcm6358_funcs[selector].groups;
	*num_groups = bcm6358_funcs[selector].num_groups;

	return 0;
}

static int bcm6358_pinctrl_set_mux(struct pinctrl_dev *pctldev,
				   unsigned selector, unsigned group)
{
	struct bcm63xx_pinctrl *pc = pinctrl_dev_get_drvdata(pctldev);
	struct bcm6358_priv *priv = pc->driver_data;
	const struct bcm6358_pingroup *pg = &bcm6358_groups[group];
	unsigned int val = pg->mode_val;
	unsigned int mask = val;
	unsigned pin;

	for (pin = 0; pin < pg->num_pins; pin++)
		mask |= (unsigned long)bcm6358_pins[pin].drv_data;

	regmap_field_update_bits(priv->overlays, mask, val);

	for (pin = 0; pin < pg->num_pins; pin++) {
		struct pinctrl_gpio_range *range;
		unsigned int hw_gpio = bcm6358_pins[pin].number;

		range = pinctrl_find_gpio_range_from_pin(pctldev, hw_gpio);
		if (range) {
			struct gpio_chip *gc = range->gc;

			if (pg->direction & BIT(pin))
				gc->direction_output(gc, hw_gpio, 0);
			else
				gc->direction_input(gc, hw_gpio);
		}
	}

	return 0;
}

static int bcm6358_gpio_request_enable(struct pinctrl_dev *pctldev,
				       struct pinctrl_gpio_range *range,
				       unsigned offset)
{
	struct bcm63xx_pinctrl *pc = pinctrl_dev_get_drvdata(pctldev);
	struct bcm6358_priv *priv = pc->driver_data;
	unsigned int mask;

	mask = (unsigned long) bcm6358_pins[offset].drv_data;
	if (!mask)
		return 0;

	/* disable all functions using this pin */
	return regmap_field_update_bits(priv->overlays, mask, 0);
}

static const struct pinctrl_ops bcm6358_pctl_ops = {
	.dt_free_map = pinctrl_utils_free_map,
	.dt_node_to_map = pinconf_generic_dt_node_to_map_pin,
	.get_group_name = bcm6358_pinctrl_get_group_name,
	.get_group_pins = bcm6358_pinctrl_get_group_pins,
	.get_groups_count = bcm6358_pinctrl_get_group_count,
};

static const struct pinmux_ops bcm6358_pmx_ops = {
	.get_function_groups = bcm6358_pinctrl_get_groups,
	.get_function_name = bcm6358_pinctrl_get_func_name,
	.get_functions_count = bcm6358_pinctrl_get_func_count,
	.gpio_request_enable = bcm6358_gpio_request_enable,
	.set_mux = bcm6358_pinctrl_set_mux,
	.strict = true,
};

static const struct bcm63xx_pinctrl_soc bcm6358_soc = {
	.ngpios = BCM6358_NUM_GPIOS,
	.npins = ARRAY_SIZE(bcm6358_pins),
	.pctl_ops = &bcm6358_pctl_ops,
	.pins = bcm6358_pins,
	.pmx_ops = &bcm6358_pmx_ops,
};

static int bcm6358_pinctrl_probe(struct platform_device *pdev)
{
	struct reg_field overlays = REG_FIELD(BCM6358_MODE_REG, 0, 15);
	struct device *dev = &pdev->dev;
	struct bcm63xx_pinctrl *pc;
	struct bcm6358_priv *priv;
	int err;

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

	err = bcm63xx_pinctrl_probe(pdev, &bcm6358_soc, (void *) priv);
	if (err)
		return err;

	pc = platform_get_drvdata(pdev);

	priv->overlays = devm_regmap_field_alloc(dev, pc->regs, overlays);
	if (IS_ERR(priv->overlays))
		return PTR_ERR(priv->overlays);

	return 0;
}

static const struct of_device_id bcm6358_pinctrl_match[] = {
	{ .compatible = "brcm,bcm6358-pinctrl", },
	{ /* sentinel */ }
};

static struct platform_driver bcm6358_pinctrl_driver = {
	.probe = bcm6358_pinctrl_probe,
	.driver = {
		.name = "bcm6358-pinctrl",
		.of_match_table = bcm6358_pinctrl_match,
	},
};

builtin_platform_driver(bcm6358_pinctrl_driver);