// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2025 Intel Corporation.
 * Copyright (c) 2025 Red Hat, Inc.
 */

#include <linux/acpi.h>
#include <linux/auxiliary_bus.h>
#include <linux/cleanup.h>
#include <linux/device.h>
#include <linux/gpio/driver.h>
#include <linux/mutex.h>
#include <linux/types.h>
#include <linux/usb/usbio.h>

struct usbio_gpio_bank {
        u8 config[USBIO_GPIOSPERBANK];
        u32 bitmap;
};

struct usbio_gpio {
        struct mutex config_mutex; /* Protects banks[x].config */
        struct usbio_gpio_bank banks[USBIO_MAX_GPIOBANKS];
        struct gpio_chip gc;
        struct auxiliary_device *adev;
};

static const struct acpi_device_id usbio_gpio_acpi_hids[] = {
        { "INTC1007" }, /* MTL */
        { "INTC10B2" }, /* ARL */
        { "INTC10B5" }, /* LNL */
        { "INTC10D1" }, /* MTL-CVF */
        { "INTC10E2" }, /* PTL */
        { }
};

static void usbio_gpio_get_bank_and_pin(struct gpio_chip *gc, unsigned int offset,
                                        struct usbio_gpio_bank **bank_ret,
                                        unsigned int *pin_ret)
{
        struct usbio_gpio *gpio = gpiochip_get_data(gc);
        struct device *dev = &gpio->adev->dev;
        struct usbio_gpio_bank *bank;
        unsigned int pin;

        bank = &gpio->banks[offset / USBIO_GPIOSPERBANK];
        pin = offset % USBIO_GPIOSPERBANK;
        if (~bank->bitmap & BIT(pin)) {
                /* The FW bitmap sometimes is invalid, warn and continue */
                dev_warn_once(dev, FW_BUG "GPIO %u is not in FW pins bitmap\n", offset);
        }

        *bank_ret = bank;
        *pin_ret = pin;
}

static int usbio_gpio_get_direction(struct gpio_chip *gc, unsigned int offset)
{
        struct usbio_gpio_bank *bank;
        unsigned int pin;
        u8 cfg;

        usbio_gpio_get_bank_and_pin(gc, offset, &bank, &pin);

        cfg = bank->config[pin] & USBIO_GPIO_PINMOD_MASK;

        return (cfg == USBIO_GPIO_PINMOD_OUTPUT) ?
                GPIO_LINE_DIRECTION_OUT : GPIO_LINE_DIRECTION_IN;
}

static int usbio_gpio_get(struct gpio_chip *gc, unsigned int offset)
{
        struct usbio_gpio *gpio = gpiochip_get_data(gc);
        struct usbio_gpio_bank *bank;
        struct usbio_gpio_rw gbuf;
        unsigned int pin;
        int ret;

        usbio_gpio_get_bank_and_pin(gc, offset, &bank, &pin);

        gbuf.bankid = offset / USBIO_GPIOSPERBANK;
        gbuf.pincount  = 1;
        gbuf.pin = pin;

        ret = usbio_control_msg(gpio->adev, USBIO_PKTTYPE_GPIO, USBIO_GPIOCMD_READ,
                                &gbuf, sizeof(gbuf) - sizeof(gbuf.value),
                                &gbuf, sizeof(gbuf));
        if (ret != sizeof(gbuf))
                return (ret < 0) ? ret : -EPROTO;

        return (le32_to_cpu(gbuf.value) >> pin) & 1;
}

static int usbio_gpio_set(struct gpio_chip *gc, unsigned int offset, int value)
{
        struct usbio_gpio *gpio = gpiochip_get_data(gc);
        struct usbio_gpio_bank *bank;
        struct usbio_gpio_rw gbuf;
        unsigned int pin;

        usbio_gpio_get_bank_and_pin(gc, offset, &bank, &pin);

        gbuf.bankid = offset / USBIO_GPIOSPERBANK;
        gbuf.pincount  = 1;
        gbuf.pin = pin;
        gbuf.value = cpu_to_le32(value << pin);

        return usbio_control_msg(gpio->adev, USBIO_PKTTYPE_GPIO, USBIO_GPIOCMD_WRITE,
                                 &gbuf, sizeof(gbuf), NULL, 0);
}

static int usbio_gpio_update_config(struct gpio_chip *gc, unsigned int offset,
                                    u8 mask, u8 value)
{
        struct usbio_gpio *gpio = gpiochip_get_data(gc);
        struct usbio_gpio_bank *bank;
        struct usbio_gpio_init gbuf;
        unsigned int pin;

        usbio_gpio_get_bank_and_pin(gc, offset, &bank, &pin);

        guard(mutex)(&gpio->config_mutex);

        bank->config[pin] &= ~mask;
        bank->config[pin] |= value;

        gbuf.bankid = offset / USBIO_GPIOSPERBANK;
        gbuf.config = bank->config[pin];
        gbuf.pincount  = 1;
        gbuf.pin = pin;

        return usbio_control_msg(gpio->adev, USBIO_PKTTYPE_GPIO, USBIO_GPIOCMD_INIT,
                                 &gbuf, sizeof(gbuf), NULL, 0);
}

static int usbio_gpio_direction_input(struct gpio_chip *gc, unsigned int offset)
{
        return usbio_gpio_update_config(gc, offset, USBIO_GPIO_PINMOD_MASK,
                                        USBIO_GPIO_SET_PINMOD(USBIO_GPIO_PINMOD_INPUT));
}

static int usbio_gpio_direction_output(struct gpio_chip *gc,
                unsigned int offset, int value)
{
        int ret;

        ret = usbio_gpio_update_config(gc, offset, USBIO_GPIO_PINMOD_MASK,
                                       USBIO_GPIO_SET_PINMOD(USBIO_GPIO_PINMOD_OUTPUT));
        if (ret)
                return ret;

        return usbio_gpio_set(gc, offset, value);
}

static int usbio_gpio_set_config(struct gpio_chip *gc, unsigned int offset,
                unsigned long config)
{
        u8 value;

        switch (pinconf_to_config_param(config)) {
        case PIN_CONFIG_BIAS_PULL_PIN_DEFAULT:
                value = USBIO_GPIO_SET_PINCFG(USBIO_GPIO_PINCFG_DEFAULT);
                break;
        case PIN_CONFIG_BIAS_PULL_UP:
                value = USBIO_GPIO_SET_PINCFG(USBIO_GPIO_PINCFG_PULLUP);
                break;
        case PIN_CONFIG_BIAS_PULL_DOWN:
                value = USBIO_GPIO_SET_PINCFG(USBIO_GPIO_PINCFG_PULLDOWN);
                break;
        case PIN_CONFIG_DRIVE_PUSH_PULL:
                value = USBIO_GPIO_SET_PINCFG(USBIO_GPIO_PINCFG_PUSHPULL);
                break;
        default:
                return -ENOTSUPP;
        }

        return usbio_gpio_update_config(gc, offset, USBIO_GPIO_PINCFG_MASK, value);
}

static int usbio_gpio_probe(struct auxiliary_device *adev,
                const struct auxiliary_device_id *adev_id)
{
        struct usbio_gpio_bank_desc *bank_desc;
        struct device *dev = &adev->dev;
        struct usbio_gpio *gpio;
        int bank, ret;

        bank_desc = dev_get_platdata(dev);
        if (!bank_desc)
                return -EINVAL;

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

        ret = devm_mutex_init(dev, &gpio->config_mutex);
        if (ret)
                return ret;

        gpio->adev = adev;

        usbio_acpi_bind(gpio->adev, usbio_gpio_acpi_hids);

        for (bank = 0; bank < USBIO_MAX_GPIOBANKS && bank_desc[bank].bmap; bank++)
                gpio->banks[bank].bitmap = le32_to_cpu(bank_desc[bank].bmap);

        gpio->gc.label = ACPI_COMPANION(dev) ?
                                        acpi_dev_name(ACPI_COMPANION(dev)) : dev_name(dev);
        gpio->gc.parent = dev;
        gpio->gc.owner = THIS_MODULE;
        gpio->gc.get_direction = usbio_gpio_get_direction;
        gpio->gc.direction_input = usbio_gpio_direction_input;
        gpio->gc.direction_output = usbio_gpio_direction_output;
        gpio->gc.get = usbio_gpio_get;
        gpio->gc.set = usbio_gpio_set;
        gpio->gc.set_config = usbio_gpio_set_config;
        gpio->gc.base = -1;
        gpio->gc.ngpio = bank * USBIO_GPIOSPERBANK;
        gpio->gc.can_sleep = true;

        ret = devm_gpiochip_add_data(dev, &gpio->gc, gpio);
        if (ret)
                return ret;

        if (has_acpi_companion(dev))
                acpi_dev_clear_dependencies(ACPI_COMPANION(dev));

        return 0;
}

static const struct auxiliary_device_id usbio_gpio_id_table[] = {
        { "usbio.usbio-gpio" },
        { }
};
MODULE_DEVICE_TABLE(auxiliary, usbio_gpio_id_table);

static struct auxiliary_driver usbio_gpio_driver = {
        .name = USBIO_GPIO_CLIENT,
        .probe = usbio_gpio_probe,
        .id_table = usbio_gpio_id_table
};
module_auxiliary_driver(usbio_gpio_driver);

MODULE_DESCRIPTION("Intel USBIO GPIO driver");
MODULE_AUTHOR("Israel Cepeda <israel.a.cepeda.lopez@intel.com>");
MODULE_AUTHOR("Hans de Goede <hansg@kernel.org>");
MODULE_LICENSE("GPL");
MODULE_IMPORT_NS("USBIO");