// SPDX-License-Identifier: GPL-2.0
/* Author: Dan Scally <djrscally@gmail.com> */

#include <linux/acpi.h>
#include <linux/array_size.h>
#include <linux/bitfield.h>
#include <linux/device.h>
#include <linux/dmi.h>
#include <linux/gpio/consumer.h>
#include <linux/gpio/machine.h>
#include <linux/i2c.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/overflow.h>
#include <linux/platform_data/x86/int3472.h>
#include <linux/platform_device.h>
#include <linux/string_choices.h>
#include <linux/uuid.h>

/*
 * 79234640-9e10-4fea-a5c1-b5aa8b19756f
 * This _DSM GUID returns information about the GPIO lines mapped to a
 * discrete INT3472 device. Function number 1 returns a count of the GPIO
 * lines that are mapped. Subsequent functions return 32 bit ints encoding
 * information about the GPIO line, including its purpose.
 */
static const guid_t int3472_gpio_guid =
        GUID_INIT(0x79234640, 0x9e10, 0x4fea,
                  0xa5, 0xc1, 0xb5, 0xaa, 0x8b, 0x19, 0x75, 0x6f);

#define INT3472_GPIO_DSM_TYPE                           GENMASK(7, 0)
#define INT3472_GPIO_DSM_PIN                            GENMASK(15, 8)
#define INT3472_GPIO_DSM_SENSOR_ON_VAL                  GENMASK(31, 24)

/*
 * 822ace8f-2814-4174-a56b-5f029fe079ee
 * This _DSM GUID returns a string from the sensor device, which acts as a
 * module identifier.
 */
static const guid_t cio2_sensor_module_guid =
        GUID_INIT(0x822ace8f, 0x2814, 0x4174,
                  0xa5, 0x6b, 0x5f, 0x02, 0x9f, 0xe0, 0x79, 0xee);

static void skl_int3472_log_sensor_module_name(struct int3472_discrete_device *int3472)
{
        union acpi_object *obj;

        obj = acpi_evaluate_dsm_typed(int3472->sensor->handle,
                                      &cio2_sensor_module_guid, 0x00,
                                      0x01, NULL, ACPI_TYPE_STRING);
        if (obj) {
                dev_dbg(int3472->dev, "Sensor module id: '%s'\n", obj->string.pointer);
                ACPI_FREE(obj);
        }
}

static int skl_int3472_fill_gpiod_lookup(struct gpiod_lookup *table_entry,
                                         struct acpi_resource_gpio *agpio,
                                         const char *con_id, unsigned long gpio_flags)
{
        char *path = agpio->resource_source.string_ptr;
        struct acpi_device *adev;
        acpi_handle handle;
        acpi_status status;

        status = acpi_get_handle(NULL, path, &handle);
        if (ACPI_FAILURE(status))
                return -EINVAL;

        adev = acpi_fetch_acpi_dev(handle);
        if (!adev)
                return -ENODEV;

        *table_entry = GPIO_LOOKUP(acpi_dev_name(adev), agpio->pin_table[0], con_id, gpio_flags);

        return 0;
}

static int skl_int3472_map_gpio_to_sensor(struct int3472_discrete_device *int3472,
                                          struct acpi_resource_gpio *agpio,
                                          const char *con_id, unsigned long gpio_flags)
{
        int ret;

        if (int3472->n_sensor_gpios >= INT3472_MAX_SENSOR_GPIOS) {
                dev_warn(int3472->dev, "Too many GPIOs mapped\n");
                return -EINVAL;
        }

        ret = skl_int3472_fill_gpiod_lookup(&int3472->gpios.table[int3472->n_sensor_gpios],
                                            agpio, con_id, gpio_flags);
        if (ret)
                return ret;

        int3472->n_sensor_gpios++;

        return 0;
}

/* This should *really* only be used when there's no other way... */
static struct gpio_desc *
skl_int3472_gpiod_get_from_temp_lookup(struct int3472_discrete_device *int3472,
                                       struct acpi_resource_gpio *agpio,
                                       const char *con_id, unsigned long gpio_flags)
{
        struct gpio_desc *desc;
        int ret;

        struct gpiod_lookup_table *lookup __free(kfree) =
                        kzalloc_flex(*lookup, table, 2);
        if (!lookup)
                return ERR_PTR(-ENOMEM);

        lookup->dev_id = dev_name(int3472->dev);
        ret = skl_int3472_fill_gpiod_lookup(&lookup->table[0], agpio, con_id, gpio_flags);
        if (ret)
                return ERR_PTR(ret);

        gpiod_add_lookup_table(lookup);
        desc = gpiod_get(int3472->dev, con_id, GPIOD_OUT_LOW);
        gpiod_remove_lookup_table(lookup);

        return desc;
}

/**
 * struct int3472_gpio_map - Map GPIOs to whatever is expected by the
 * sensor driver (as in DT bindings)
 * @hid: The ACPI HID of the device without the instance number e.g. INT347E
 * @type_from: The GPIO type from ACPI ?SDT
 * @type_to: The assigned GPIO type, typically same as @type_from
 * @enable_time_us: Enable time in usec for GPIOs mapped to regulators
 * @con_id: The name of the GPIO for the device
 * @polarity_low: GPIO_ACTIVE_LOW true if the @polarity_low is true,
 * GPIO_ACTIVE_HIGH otherwise
 */
struct int3472_gpio_map {
        const char *hid;
        u8 type_from;
        u8 type_to;
        bool polarity_low;
        unsigned int enable_time_us;
        const char *con_id;
};

static const struct int3472_gpio_map int3472_gpio_map[] = {
        {       /* mt9m114 designs declare a powerdown pin which controls the regulators */
                .hid = "INT33F0",
                .type_from = INT3472_GPIO_TYPE_POWERDOWN,
                .type_to = INT3472_GPIO_TYPE_POWER_ENABLE,
                .con_id = "vdd",
                .enable_time_us = GPIO_REGULATOR_ENABLE_TIME,
        },
        {       /* ov7251 driver / DT-bindings expect "enable" as con_id for reset */
                .hid = "INT347E",
                .type_from = INT3472_GPIO_TYPE_RESET,
                .type_to = INT3472_GPIO_TYPE_RESET,
                .con_id = "enable",
        },
        {       /* ov08x40's handshake pin needs a 45 ms delay on some HP laptops */
                .hid = "OVTI08F4",
                .type_from = INT3472_GPIO_TYPE_HANDSHAKE,
                .type_to = INT3472_GPIO_TYPE_HANDSHAKE,
                .con_id = "dvdd",
                .enable_time_us = 45 * USEC_PER_MSEC,
        },
};

static void int3472_get_con_id_and_polarity(struct int3472_discrete_device *int3472, u8 *type,
                                            const char **con_id, unsigned long *gpio_flags,
                                            unsigned int *enable_time_us)
{
        struct acpi_device *adev = int3472->sensor;
        unsigned int i;

        for (i = 0; i < ARRAY_SIZE(int3472_gpio_map); i++) {
                /*
                 * Map the firmware-provided GPIO to whatever a driver expects
                 * (as in DT bindings). First check if the type matches with the
                 * GPIO map, then further check that the device _HID matches.
                 */
                if (*type != int3472_gpio_map[i].type_from)
                        continue;

                if (!acpi_dev_hid_uid_match(adev, int3472_gpio_map[i].hid, NULL))
                        continue;

                dev_dbg(int3472->dev, "mapping type 0x%02x pin to 0x%02x %s\n",
                        *type, int3472_gpio_map[i].type_to, int3472_gpio_map[i].con_id);

                *type = int3472_gpio_map[i].type_to;
                *gpio_flags = int3472_gpio_map[i].polarity_low ?
                              GPIO_ACTIVE_LOW : GPIO_ACTIVE_HIGH;
                *con_id = int3472_gpio_map[i].con_id;
                *enable_time_us = int3472_gpio_map[i].enable_time_us;
                return;
        }

        *enable_time_us = GPIO_REGULATOR_ENABLE_TIME;

        switch (*type) {
        case INT3472_GPIO_TYPE_RESET:
                *con_id = "reset";
                *gpio_flags = GPIO_ACTIVE_LOW;
                break;
        case INT3472_GPIO_TYPE_POWERDOWN:
                *con_id = "powerdown";
                *gpio_flags = GPIO_ACTIVE_LOW;
                break;
        case INT3472_GPIO_TYPE_CLK_ENABLE:
                *con_id = "clk-enable";
                *gpio_flags = GPIO_ACTIVE_HIGH;
                break;
        case INT3472_GPIO_TYPE_PRIVACY_LED:
                *con_id = "privacy-led";
                *gpio_flags = GPIO_ACTIVE_HIGH;
                break;
        case INT3472_GPIO_TYPE_HOTPLUG_DETECT:
                *con_id = "hpd";
                *gpio_flags = GPIO_ACTIVE_HIGH;
                break;
        case INT3472_GPIO_TYPE_POWER_ENABLE:
                *con_id = "avdd";
                *gpio_flags = GPIO_ACTIVE_HIGH;
                break;
        case INT3472_GPIO_TYPE_DOVDD:
                *con_id = "dovdd";
                *gpio_flags = GPIO_ACTIVE_HIGH;
                break;
        case INT3472_GPIO_TYPE_HANDSHAKE:
                *con_id = "dvdd";
                *gpio_flags = GPIO_ACTIVE_HIGH;
                /* Setups using a handshake pin need 25 ms enable delay */
                *enable_time_us = 25 * USEC_PER_MSEC;
                break;
        default:
                *con_id = "unknown";
                *gpio_flags = GPIO_ACTIVE_HIGH;
                break;
        }
}

/**
 * skl_int3472_handle_gpio_resources: Map PMIC resources to consuming sensor
 * @ares: A pointer to a &struct acpi_resource
 * @data: A pointer to a &struct int3472_discrete_device
 *
 * This function handles GPIO resources that are against an INT3472
 * ACPI device, by checking the value of the corresponding _DSM entry.
 * This will return a 32bit int, where the lowest byte represents the
 * function of the GPIO pin:
 *
 * 0x00 Reset
 * 0x01 Power down
 * 0x0b Power enable
 * 0x0c Clock enable
 * 0x0d Privacy LED
 * 0x10 DOVDD (digital I/O voltage)
 * 0x13 Hotplug detect
 *
 * There are some known platform specific quirks where that does not quite
 * hold up; for example where a pin with type 0x01 (Power down) is mapped to
 * a sensor pin that performs a reset function or entries in _CRS and _DSM that
 * do not actually correspond to a physical connection. These will be handled
 * by the mapping sub-functions.
 *
 * GPIOs will either be mapped directly to the sensor device or else used
 * to create clocks and regulators via the usual frameworks.
 *
 * Return:
 * * 1          - Continue the loop without adding a copy of the resource to
 * *              the list passed to acpi_dev_get_resources()
 * * 0          - Continue the loop after adding a copy of the resource to
 * *              the list passed to acpi_dev_get_resources()
 * * -errno     - Error, break loop
 */
static int skl_int3472_handle_gpio_resources(struct acpi_resource *ares,
                                             void *data)
{
        struct int3472_discrete_device *int3472 = data;
        const char *second_sensor = NULL;
        struct acpi_resource_gpio *agpio;
        unsigned int enable_time_us;
        u8 active_value, pin, type;
        unsigned long gpio_flags;
        union acpi_object *obj;
        struct gpio_desc *gpio;
        const char *err_msg;
        const char *con_id;
        int ret;

        if (!acpi_gpio_get_io_resource(ares, &agpio))
                return 1;

        /*
         * ngpios + 2 because the index of this _DSM function is 1-based and
         * the first function is just a count.
         */
        obj = acpi_evaluate_dsm_typed(int3472->adev->handle,
                                      &int3472_gpio_guid, 0x00,
                                      int3472->ngpios + 2,
                                      NULL, ACPI_TYPE_INTEGER);

        if (!obj) {
                dev_warn(int3472->dev, "No _DSM entry for GPIO pin %u\n",
                         agpio->pin_table[0]);
                return 1;
        }

        type = FIELD_GET(INT3472_GPIO_DSM_TYPE, obj->integer.value);

        int3472_get_con_id_and_polarity(int3472, &type, &con_id, &gpio_flags, &enable_time_us);

        pin = FIELD_GET(INT3472_GPIO_DSM_PIN, obj->integer.value);
        /* Pin field is not really used under Windows and wraps around at 8 bits */
        if (pin != (agpio->pin_table[0] & 0xff))
                dev_dbg(int3472->dev, FW_BUG "%s %s pin number mismatch _DSM %d resource %d\n",
                        con_id, agpio->resource_source.string_ptr, pin, agpio->pin_table[0]);

        active_value = FIELD_GET(INT3472_GPIO_DSM_SENSOR_ON_VAL, obj->integer.value);
        if (!active_value)
                gpio_flags ^= GPIO_ACTIVE_LOW;

        dev_dbg(int3472->dev, "%s %s pin %d active-%s\n", con_id,
                agpio->resource_source.string_ptr, agpio->pin_table[0],
                str_high_low(gpio_flags == GPIO_ACTIVE_HIGH));

        switch (type) {
        case INT3472_GPIO_TYPE_RESET:
        case INT3472_GPIO_TYPE_POWERDOWN:
        case INT3472_GPIO_TYPE_HOTPLUG_DETECT:
                ret = skl_int3472_map_gpio_to_sensor(int3472, agpio, con_id, gpio_flags);
                if (ret)
                        err_msg = "Failed to map GPIO pin to sensor\n";

                break;
        case INT3472_GPIO_TYPE_CLK_ENABLE:
        case INT3472_GPIO_TYPE_PRIVACY_LED:
        case INT3472_GPIO_TYPE_POWER_ENABLE:
        case INT3472_GPIO_TYPE_DOVDD:
        case INT3472_GPIO_TYPE_HANDSHAKE:
                gpio = skl_int3472_gpiod_get_from_temp_lookup(int3472, agpio, con_id, gpio_flags);
                if (IS_ERR(gpio)) {
                        ret = PTR_ERR(gpio);
                        err_msg = "Failed to get GPIO\n";
                        break;
                }

                switch (type) {
                case INT3472_GPIO_TYPE_CLK_ENABLE:
                        ret = skl_int3472_register_gpio_clock(int3472, gpio);
                        if (ret)
                                err_msg = "Failed to register clock\n";

                        break;
                case INT3472_GPIO_TYPE_PRIVACY_LED:
                        ret = skl_int3472_register_pled(int3472, gpio);
                        if (ret)
                                err_msg = "Failed to register LED\n";

                        break;
                case INT3472_GPIO_TYPE_POWER_ENABLE:
                        second_sensor = int3472->quirks.avdd_second_sensor;
                        fallthrough;
                case INT3472_GPIO_TYPE_DOVDD:
                case INT3472_GPIO_TYPE_HANDSHAKE:
                        ret = skl_int3472_register_regulator(int3472, gpio, enable_time_us,
                                                             con_id, second_sensor);
                        if (ret)
                                err_msg = "Failed to register regulator\n";

                        break;
                default: /* Never reached */
                        ret = -EINVAL;
                        break;
                }

                if (ret)
                        gpiod_put(gpio);

                break;
        default:
                dev_warn(int3472->dev,
                         "GPIO type 0x%02x unknown; the sensor may not work\n",
                         type);
                ret = 1;
                break;
        }

        int3472->ngpios++;
        ACPI_FREE(obj);

        if (ret < 0)
                return dev_err_probe(int3472->dev, ret, err_msg);

        /* Tell acpi_dev_get_resources() to not make a copy of the resource */
        return 1;
}

int int3472_discrete_parse_crs(struct int3472_discrete_device *int3472)
{
        LIST_HEAD(resource_list);
        int ret;

        skl_int3472_log_sensor_module_name(int3472);

        ret = acpi_dev_get_resources(int3472->adev, &resource_list,
                                     skl_int3472_handle_gpio_resources,
                                     int3472);
        if (ret < 0)
                return ret;

        acpi_dev_free_resource_list(&resource_list);

        /* Register _DSM based clock (no-op if a GPIO clock was already registered) */
        ret = skl_int3472_register_dsm_clock(int3472);
        if (ret < 0)
                return ret;

        int3472->gpios.dev_id = int3472->sensor_name;
        gpiod_add_lookup_table(&int3472->gpios);

        return 0;
}
EXPORT_SYMBOL_NS_GPL(int3472_discrete_parse_crs, "INTEL_INT3472_DISCRETE");

void int3472_discrete_cleanup(struct int3472_discrete_device *int3472)
{
        gpiod_remove_lookup_table(&int3472->gpios);

        skl_int3472_unregister_clock(int3472);
        skl_int3472_unregister_pled(int3472);
        skl_int3472_unregister_regulator(int3472);
}
EXPORT_SYMBOL_NS_GPL(int3472_discrete_cleanup, "INTEL_INT3472_DISCRETE");

static void skl_int3472_discrete_remove(struct platform_device *pdev)
{
        int3472_discrete_cleanup(platform_get_drvdata(pdev));
}

static int skl_int3472_discrete_probe(struct platform_device *pdev)
{
        struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
        const struct int3472_discrete_quirks *quirks = NULL;
        struct int3472_discrete_device *int3472;
        const struct dmi_system_id *id;
        struct int3472_cldb cldb;
        int ret;

        if (!adev)
                return -ENODEV;

        id = dmi_first_match(skl_int3472_discrete_quirks);
        if (id)
                quirks = id->driver_data;

        ret = skl_int3472_fill_cldb(adev, &cldb);
        if (ret) {
                dev_err(&pdev->dev, "Couldn't fill CLDB structure\n");
                return ret;
        }

        if (cldb.control_logic_type != 1) {
                dev_err(&pdev->dev, "Unsupported control logic type %u\n",
                        cldb.control_logic_type);
                return -EINVAL;
        }

        /* Max num GPIOs we've seen plus a terminator */
        int3472 = devm_kzalloc(&pdev->dev, struct_size(int3472, gpios.table,
                               INT3472_MAX_SENSOR_GPIOS + 1), GFP_KERNEL);
        if (!int3472)
                return -ENOMEM;

        int3472->adev = adev;
        int3472->dev = &pdev->dev;
        platform_set_drvdata(pdev, int3472);
        int3472->clock.imgclk_index = cldb.clock_source;

        if (quirks)
                int3472->quirks = *quirks;

        ret = skl_int3472_get_sensor_adev_and_name(&pdev->dev, &int3472->sensor,
                                                   &int3472->sensor_name);
        if (ret)
                return ret;

        /*
         * Initialising this list means we can call gpiod_remove_lookup_table()
         * in failure paths without issue.
         */
        INIT_LIST_HEAD(&int3472->gpios.list);

        ret = int3472_discrete_parse_crs(int3472);
        if (ret) {
                skl_int3472_discrete_remove(pdev);
                return ret;
        }

        acpi_dev_clear_dependencies(adev);
        return 0;
}

static const struct acpi_device_id int3472_device_id[] = {
        { "INT3472", 0 },
        { }
};
MODULE_DEVICE_TABLE(acpi, int3472_device_id);

static struct platform_driver int3472_discrete = {
        .driver = {
                .name = "int3472-discrete",
                .acpi_match_table = int3472_device_id,
        },
        .probe = skl_int3472_discrete_probe,
        .remove = skl_int3472_discrete_remove,
};
module_platform_driver(int3472_discrete);

MODULE_DESCRIPTION("Intel SkyLake INT3472 ACPI Discrete Device Driver");
MODULE_AUTHOR("Daniel Scally <djrscally@gmail.com>");
MODULE_LICENSE("GPL v2");
MODULE_IMPORT_NS("INTEL_INT3472");