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

#include <linux/acpi.h>
#include <linux/clkdev.h>
#include <linux/clk-provider.h>
#include <linux/device.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_device.h>
#include <linux/uuid.h>

#include "intel_skl_int3472_common.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);

/*
 * 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);

/*
 * Here follows platform specific mapping information that we can pass to
 * the functions mapping resources to the sensors. Where the sensors have
 * a power enable pin defined in DSDT we need to provide a supply name so
 * the sensor drivers can find the regulator. The device name will be derived
 * from the sensor's ACPI device within the code. Optionally, we can provide a
 * NULL terminated array of function name mappings to deal with any platform
 * specific deviations from the documented behaviour of GPIOs.
 *
 * Map a GPIO function name to NULL to prevent the driver from mapping that
 * GPIO at all.
 */

static const struct int3472_gpio_function_remap ov2680_gpio_function_remaps[] = {
        { "reset", NULL },
        { "powerdown", "reset" },
        { }
};

static const struct int3472_sensor_config int3472_sensor_configs[] = {
        /* Lenovo Miix 510-12ISK - OV2680, Front */
        { "GNDF140809R", { 0 }, ov2680_gpio_function_remaps },
        /* Lenovo Miix 510-12ISK - OV5648, Rear */
        { "GEFF150023R", REGULATOR_SUPPLY("avdd", NULL), NULL },
        /* Surface Go 1&2 - OV5693, Front */
        { "YHCU", REGULATOR_SUPPLY("avdd", NULL), NULL },
};

static const struct int3472_sensor_config *
skl_int3472_get_sensor_module_config(struct int3472_discrete_device *int3472)
{
        union acpi_object *obj;
        unsigned int i;

        obj = acpi_evaluate_dsm_typed(int3472->sensor->handle,
                                      &cio2_sensor_module_guid, 0x00,
                                      0x01, NULL, ACPI_TYPE_STRING);

        if (!obj) {
                dev_err(int3472->dev,
                        "Failed to get sensor module string from _DSM\n");
                return ERR_PTR(-ENODEV);
        }

        if (obj->string.type != ACPI_TYPE_STRING) {
                dev_err(int3472->dev,
                        "Sensor _DSM returned a non-string value\n");

                ACPI_FREE(obj);
                return ERR_PTR(-EINVAL);
        }

        for (i = 0; i < ARRAY_SIZE(int3472_sensor_configs); i++) {
                if (!strcmp(int3472_sensor_configs[i].sensor_module_name,
                            obj->string.pointer))
                        break;
        }

        ACPI_FREE(obj);

        if (i >= ARRAY_SIZE(int3472_sensor_configs))
                return ERR_PTR(-EINVAL);

        return &int3472_sensor_configs[i];
}

static int skl_int3472_map_gpio_to_sensor(struct int3472_discrete_device *int3472,
                                          struct acpi_resource_gpio *agpio,
                                          const char *func, u32 polarity)
{
        const struct int3472_sensor_config *sensor_config;
        char *path = agpio->resource_source.string_ptr;
        struct gpiod_lookup *table_entry;
        struct acpi_device *adev;
        acpi_handle handle;
        acpi_status status;
        int ret;

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

        sensor_config = int3472->sensor_config;
        if (!IS_ERR(sensor_config) && sensor_config->function_maps) {
                const struct int3472_gpio_function_remap *remap;

                for (remap = sensor_config->function_maps; remap->documented; remap++) {
                        if (!strcmp(func, remap->documented)) {
                                func = remap->actual;
                                break;
                        }
                }
        }

        /* Functions mapped to NULL should not be mapped to the sensor */
        if (!func)
                return 0;

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

        ret = acpi_bus_get_device(handle, &adev);
        if (ret)
                return -ENODEV;

        table_entry = &int3472->gpios.table[int3472->n_sensor_gpios];
        table_entry->key = acpi_dev_name(adev);
        table_entry->chip_hwnum = agpio->pin_table[0];
        table_entry->con_id = func;
        table_entry->idx = 0;
        table_entry->flags = polarity;

        int3472->n_sensor_gpios++;

        return 0;
}

static int skl_int3472_map_gpio_to_clk(struct int3472_discrete_device *int3472,
                                       struct acpi_resource_gpio *agpio, u8 type)
{
        char *path = agpio->resource_source.string_ptr;
        u16 pin = agpio->pin_table[0];
        struct gpio_desc *gpio;

        switch (type) {
        case INT3472_GPIO_TYPE_CLK_ENABLE:
                gpio = acpi_get_and_request_gpiod(path, pin, "int3472,clk-enable");
                if (IS_ERR(gpio))
                        return (PTR_ERR(gpio));

                int3472->clock.ena_gpio = gpio;
                break;
        case INT3472_GPIO_TYPE_PRIVACY_LED:
                gpio = acpi_get_and_request_gpiod(path, pin, "int3472,privacy-led");
                if (IS_ERR(gpio))
                        return (PTR_ERR(gpio));

                int3472->clock.led_gpio = gpio;
                break;
        default:
                dev_err(int3472->dev, "Invalid GPIO type 0x%02x for clock\n", type);
                break;
        }

        return 0;
}

/**
 * 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
 *
 * 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          - To continue the loop
 * * 0          - When all resources found are handled properly.
 * * -EINVAL    - If the resource is not a GPIO IO resource
 * * -ENODEV    - If the resource has no corresponding _DSM entry
 * * -Other     - Errors propagated from one of the sub-functions.
 */
static int skl_int3472_handle_gpio_resources(struct acpi_resource *ares,
                                             void *data)
{
        struct int3472_discrete_device *int3472 = data;
        struct acpi_resource_gpio *agpio;
        union acpi_object *obj;
        const char *err_msg;
        int ret;
        u8 type;

        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 = obj->integer.value & 0xff;

        switch (type) {
        case INT3472_GPIO_TYPE_RESET:
                ret = skl_int3472_map_gpio_to_sensor(int3472, agpio, "reset",
                                                     GPIO_ACTIVE_LOW);
                if (ret)
                        err_msg = "Failed to map reset pin to sensor\n";

                break;
        case INT3472_GPIO_TYPE_POWERDOWN:
                ret = skl_int3472_map_gpio_to_sensor(int3472, agpio, "powerdown",
                                                     GPIO_ACTIVE_LOW);
                if (ret)
                        err_msg = "Failed to map powerdown pin to sensor\n";

                break;
        case INT3472_GPIO_TYPE_CLK_ENABLE:
        case INT3472_GPIO_TYPE_PRIVACY_LED:
                ret = skl_int3472_map_gpio_to_clk(int3472, agpio, type);
                if (ret)
                        err_msg = "Failed to map GPIO to clock\n";

                break;
        case INT3472_GPIO_TYPE_POWER_ENABLE:
                ret = skl_int3472_register_regulator(int3472, agpio);
                if (ret)
                        err_msg = "Failed to map regulator to sensor\n";

                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);

        return ret;
}

static int skl_int3472_parse_crs(struct int3472_discrete_device *int3472)
{
        LIST_HEAD(resource_list);
        int ret;

        /*
         * No error check, because not having a sensor config is not necessarily
         * a failure mode.
         */
        int3472->sensor_config = skl_int3472_get_sensor_module_config(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);

        /*
         * If we find no clock enable GPIO pin then the privacy LED won't work.
         * We've never seen that situation, but it's possible. Warn the user so
         * it's clear what's happened.
         */
        if (int3472->clock.ena_gpio) {
                ret = skl_int3472_register_clock(int3472);
                if (ret)
                        return ret;
        } else {
                if (int3472->clock.led_gpio)
                        dev_warn(int3472->dev,
                                 "No clk GPIO. The privacy LED won't work\n");
        }

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

        return 0;
}

int skl_int3472_discrete_probe(struct platform_device *pdev)
{
        struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
        struct int3472_discrete_device *int3472;
        struct int3472_cldb cldb;
        int ret;

        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->sensor = acpi_dev_get_first_consumer_dev(adev);
        if (!int3472->sensor) {
                dev_err(&pdev->dev, "INT3472 seems to have no dependents.\n");
                return -ENODEV;
        }

        int3472->sensor_name = devm_kasprintf(int3472->dev, GFP_KERNEL,
                                              I2C_DEV_NAME_FORMAT,
                                              acpi_dev_name(int3472->sensor));
        if (!int3472->sensor_name) {
                ret = -ENOMEM;
                goto err_put_sensor;
        }

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

        ret = skl_int3472_parse_crs(int3472);
        if (ret) {
                skl_int3472_discrete_remove(pdev);
                return ret;
        }

        return 0;

err_put_sensor:
        acpi_dev_put(int3472->sensor);

        return ret;
}

int skl_int3472_discrete_remove(struct platform_device *pdev)
{
        struct int3472_discrete_device *int3472 = platform_get_drvdata(pdev);

        gpiod_remove_lookup_table(&int3472->gpios);

        if (int3472->clock.cl)
                skl_int3472_unregister_clock(int3472);

        gpiod_put(int3472->clock.ena_gpio);
        gpiod_put(int3472->clock.led_gpio);

        skl_int3472_unregister_regulator(int3472);

        return 0;
}