/*
 * Copyright (c) 2020 Henrik Brix Andersen <henrik@brixandersen.dk>
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#define DT_DRV_COMPAT xlnx_xps_gpio_1_00_a

#include <zephyr/device.h>
#include <zephyr/drivers/gpio.h>
#include <zephyr/irq.h>
#include <zephyr/sys/sys_io.h>

#include <zephyr/drivers/gpio/gpio_utils.h>

/* AXI GPIO v2 register offsets (See Xilinx PG144 for details) */
#define GPIO_DATA_OFFSET  0x0000
#define GPIO_TRI_OFFSET   0x0004
#define GPIO2_DATA_OFFSET 0x0008
#define GPIO2_TRI_OFFSET  0x000c
#define GIER_OFFSET       0x011c
#define IPISR_OFFSET      0x0120
#define IPIER_OFFSET      0x0128

/* GIER bit definitions */
#define GIER_GIE BIT(31)

/* IPISR and IPIER bit definitions */
#define IPIXX_CH1_IE BIT(0)
#define IPIXX_CH2_IE BIT(1)

/* Maximum number of GPIOs supported per channel */
#define MAX_GPIOS 32

struct gpio_xlnx_axi_config {
	/* gpio_driver_config needs to be first */
	struct gpio_driver_config common;
	mm_reg_t base;
	bool all_inputs : 1;
	bool all_outputs : 1;
};

struct gpio_xlnx_axi_data {
	/* gpio_driver_data needs to be first */
	struct gpio_driver_data common;
	/* Shadow registers for data out and tristate */
	uint32_t dout;
	uint32_t tri;
};

static inline uint32_t gpio_xlnx_axi_read_data(const struct device *dev)
{
	const struct gpio_xlnx_axi_config *config = dev->config;

	return sys_read32(config->base + GPIO_DATA_OFFSET);
}

static inline void gpio_xlnx_axi_write_data(const struct device *dev,
					    uint32_t val)
{
	const struct gpio_xlnx_axi_config *config = dev->config;

	sys_write32(val, config->base + GPIO_DATA_OFFSET);
}

static inline void gpio_xlnx_axi_write_tri(const struct device *dev,
					   uint32_t val)
{
	const struct gpio_xlnx_axi_config *config = dev->config;

	sys_write32(val, config->base + GPIO_TRI_OFFSET);
}

static int gpio_xlnx_axi_pin_configure(const struct device *dev,
				       gpio_pin_t pin,
				       gpio_flags_t flags)
{
	const struct gpio_xlnx_axi_config *config = dev->config;
	struct gpio_xlnx_axi_data *data = dev->data;
	unsigned int key;

	if (!(BIT(pin) & config->common.port_pin_mask)) {
		return -EINVAL;
	}

	if (((flags & GPIO_INPUT) != 0) && ((flags & GPIO_OUTPUT) != 0)) {
		return -ENOTSUP;
	}

	if ((flags & GPIO_SINGLE_ENDED) != 0) {
		return -ENOTSUP;
	}

	if ((flags & (GPIO_PULL_UP | GPIO_PULL_DOWN)) != 0) {
		return -ENOTSUP;
	}

	if (((flags & GPIO_INPUT) != 0) && config->all_outputs) {
		return -ENOTSUP;
	}

	if (((flags & GPIO_OUTPUT) != 0) && config->all_inputs) {
		return -ENOTSUP;
	}

	key = irq_lock();

	switch (flags & GPIO_DIR_MASK) {
	case GPIO_INPUT:
		data->tri |= BIT(pin);
		break;
	case GPIO_OUTPUT:
		if ((flags & GPIO_OUTPUT_INIT_HIGH) != 0) {
			data->dout |= BIT(pin);
		} else if ((flags & GPIO_OUTPUT_INIT_LOW) != 0) {
			data->dout &= ~BIT(pin);
		}
		data->tri &= ~BIT(pin);
		break;
	default:
		return -ENOTSUP;
	}

	gpio_xlnx_axi_write_data(dev, data->dout);
	gpio_xlnx_axi_write_tri(dev, data->tri);

	irq_unlock(key);

	return 0;
}

static int gpio_xlnx_axi_port_get_raw(const struct device *dev,
				      gpio_port_value_t *value)
{
	*value = gpio_xlnx_axi_read_data(dev);
	return 0;
}

static int gpio_xlnx_axi_port_set_masked_raw(const struct device *dev,
					     gpio_port_pins_t mask,
					     gpio_port_value_t value)
{
	struct gpio_xlnx_axi_data *data = dev->data;
	unsigned int key;

	key = irq_lock();
	data->dout = (data->dout & ~mask) | (mask & value);
	gpio_xlnx_axi_write_data(dev, data->dout);
	irq_unlock(key);

	return 0;
}

static int gpio_xlnx_axi_port_set_bits_raw(const struct device *dev,
					   gpio_port_pins_t pins)
{
	struct gpio_xlnx_axi_data *data = dev->data;
	unsigned int key;

	key = irq_lock();
	data->dout |= pins;
	gpio_xlnx_axi_write_data(dev, data->dout);
	irq_unlock(key);

	return 0;
}

static int gpio_xlnx_axi_port_clear_bits_raw(const struct device *dev,
					     gpio_port_pins_t pins)
{
	struct gpio_xlnx_axi_data *data = dev->data;
	unsigned int key;

	key = irq_lock();
	data->dout &= ~pins;
	gpio_xlnx_axi_write_data(dev, data->dout);
	irq_unlock(key);

	return 0;
}

static int gpio_xlnx_axi_port_toggle_bits(const struct device *dev,
					  gpio_port_pins_t pins)
{
	struct gpio_xlnx_axi_data *data = dev->data;
	unsigned int key;

	key = irq_lock();
	data->dout ^= pins;
	gpio_xlnx_axi_write_data(dev, data->dout);
	irq_unlock(key);

	return 0;
}

static int gpio_xlnx_axi_pin_interrupt_configure(const struct device *dev,
						 gpio_pin_t pin,
						 enum gpio_int_mode mode,
						 enum gpio_int_trig trig)
{
	ARG_UNUSED(dev);
	ARG_UNUSED(pin);
	ARG_UNUSED(mode);
	ARG_UNUSED(trig);

	/*
	 * The Xilinx AXI GPIO IP only supports a port-wide pin change
	 * interrupt. This does not map well to the current Zephyr GPIO IRQ API.
	 */
	return -ENOTSUP;
}

static int gpio_xlnx_axi_manage_callback(const struct device *dev,
					 struct gpio_callback *cb,
					 bool set)
{
	ARG_UNUSED(dev);
	ARG_UNUSED(cb);
	ARG_UNUSED(set);

	return -ENOTSUP;
}

static uint32_t gpio_xlnx_axi_get_pending_int(const struct device *dev)
{
	return 0;
}

static int gpio_xlnx_axi_init(const struct device *dev)
{
	struct gpio_xlnx_axi_data *data = dev->data;

	gpio_xlnx_axi_write_data(dev, data->dout);
	gpio_xlnx_axi_write_tri(dev, data->tri);

	return 0;
}

static const struct gpio_driver_api gpio_xlnx_axi_driver_api = {
	.pin_configure = gpio_xlnx_axi_pin_configure,
	.port_get_raw = gpio_xlnx_axi_port_get_raw,
	.port_set_masked_raw = gpio_xlnx_axi_port_set_masked_raw,
	.port_set_bits_raw = gpio_xlnx_axi_port_set_bits_raw,
	.port_clear_bits_raw = gpio_xlnx_axi_port_clear_bits_raw,
	.port_toggle_bits = gpio_xlnx_axi_port_toggle_bits,
	.pin_interrupt_configure = gpio_xlnx_axi_pin_interrupt_configure,
	.manage_callback = gpio_xlnx_axi_manage_callback,
	.get_pending_int = gpio_xlnx_axi_get_pending_int,
};

#define GPIO_XLNX_AXI_GPIO2_HAS_COMPAT_STATUS_OKAY(n)			\
	UTIL_AND(							\
		DT_NODE_HAS_COMPAT(DT_INST_CHILD(n, gpio2),		\
				   xlnx_xps_gpio_1_00_a_gpio2),		\
		DT_NODE_HAS_STATUS(DT_INST_CHILD(n, gpio2), okay)	\
		)

#define GPIO_XLNX_AXI_GPIO2_COND_INIT(n)				\
	IF_ENABLED(UTIL_AND(						\
			DT_INST_PROP_OR(n, xlnx_is_dual, 1),		\
			GPIO_XLNX_AXI_GPIO2_HAS_COMPAT_STATUS_OKAY(n)	\
			),						\
		(GPIO_XLNX_AXI_GPIO2_INIT(n)));

#define GPIO_XLNX_AXI_GPIO2_INIT(n)					\
	static struct gpio_xlnx_axi_data gpio_xlnx_axi_##n##_2_data = {	\
		.dout = DT_INST_PROP_OR(n, xlnx_dout_default_2, 0),	\
		.tri = DT_INST_PROP_OR(n, xlnx_tri_default_2,		\
				       GENMASK(MAX_GPIOS - 1, 0)),	\
	};								\
									\
	static const struct gpio_xlnx_axi_config			\
		gpio_xlnx_axi_##n##_2_config = {			\
		.common = {						\
			.port_pin_mask = GPIO_PORT_PIN_MASK_FROM_NGPIOS(\
				DT_INST_PROP_OR(n, xlnx_gpio2_width,	\
						MAX_GPIOS)),		\
		},							\
		.base = DT_INST_REG_ADDR(n) + GPIO2_DATA_OFFSET,	\
		.all_inputs = DT_INST_PROP_OR(n, xlnx_all_inputs2, 0),	\
		.all_outputs = DT_INST_PROP_OR(n, xlnx_all_outputs2, 0),\
	};								\
									\
	DEVICE_DT_DEFINE(DT_INST_CHILD(n, gpio2),			\
			&gpio_xlnx_axi_init,				\
			NULL,						\
			&gpio_xlnx_axi_##n##_2_data,			\
			&gpio_xlnx_axi_##n##_2_config,			\
			PRE_KERNEL_1,					\
			CONFIG_GPIO_INIT_PRIORITY,			\
			&gpio_xlnx_axi_driver_api);

#define GPIO_XLNX_AXI_INIT(n)						\
	static struct gpio_xlnx_axi_data gpio_xlnx_axi_##n##_data = {	\
		.dout = DT_INST_PROP_OR(n, xlnx_dout_default, 0),	\
		.tri = DT_INST_PROP_OR(n, xlnx_tri_default,		\
				       GENMASK(MAX_GPIOS - 1, 0)),	\
	};								\
									\
	static const struct gpio_xlnx_axi_config			\
		gpio_xlnx_axi_##n##_config = {				\
		.common = {						\
			.port_pin_mask = GPIO_PORT_PIN_MASK_FROM_NGPIOS(\
				DT_INST_PROP_OR(n, xlnx_gpio_width,	\
						MAX_GPIOS)),		\
		},							\
		.base = DT_INST_REG_ADDR(n),				\
		.all_inputs = DT_INST_PROP_OR(n, xlnx_all_inputs, 0),	\
		.all_outputs = DT_INST_PROP_OR(n, xlnx_all_outputs, 0),	\
	};								\
									\
	DEVICE_DT_INST_DEFINE(n,					\
			&gpio_xlnx_axi_init,				\
			NULL,						\
			&gpio_xlnx_axi_##n##_data,			\
			&gpio_xlnx_axi_##n##_config,			\
			PRE_KERNEL_1,					\
			CONFIG_GPIO_INIT_PRIORITY,			\
			&gpio_xlnx_axi_driver_api);			\
	GPIO_XLNX_AXI_GPIO2_COND_INIT(n);

DT_INST_FOREACH_STATUS_OKAY(GPIO_XLNX_AXI_INIT)