// SPDX--License-Identifier: GPL-2.0

#include <asm/platform_early.h>
#include <linux/mod_devicetable.h>
#include <linux/pm.h>

static __initdata LIST_HEAD(sh_early_platform_driver_list);
static __initdata LIST_HEAD(sh_early_platform_device_list);

static const struct platform_device_id *
platform_match_id(const struct platform_device_id *id,
                  struct platform_device *pdev)
{
        while (id->name[0]) {
                if (strcmp(pdev->name, id->name) == 0) {
                        pdev->id_entry = id;
                        return id;
                }
                id++;
        }
        return NULL;
}

static int platform_match(struct device *dev, struct device_driver *drv)
{
        struct platform_device *pdev = to_platform_device(dev);
        struct platform_driver *pdrv = to_platform_driver(drv);

        /* Then try to match against the id table */
        if (pdrv->id_table)
                return platform_match_id(pdrv->id_table, pdev) != NULL;

        /* fall-back to driver name match */
        return (strcmp(pdev->name, drv->name) == 0);
}

#ifdef CONFIG_PM
static void device_pm_init_common(struct device *dev)
{
        if (!dev->power.early_init) {
                spin_lock_init(&dev->power.lock);
                dev->power.qos = NULL;
                dev->power.early_init = true;
        }
}

static void pm_runtime_early_init(struct device *dev)
{
        dev->power.disable_depth = 1;
        device_pm_init_common(dev);
}
#else
static void pm_runtime_early_init(struct device *dev) {}
#endif

/**
 * sh_early_platform_driver_register - register early platform driver
 * @epdrv: sh_early_platform driver structure
 * @buf: string passed from early_param()
 *
 * Helper function for sh_early_platform_init() / sh_early_platform_init_buffer()
 */
int __init sh_early_platform_driver_register(struct sh_early_platform_driver *epdrv,
                                          char *buf)
{
        char *tmp;
        int n;

        /* Simply add the driver to the end of the global list.
         * Drivers will by default be put on the list in compiled-in order.
         */
        if (!epdrv->list.next) {
                INIT_LIST_HEAD(&epdrv->list);
                list_add_tail(&epdrv->list, &sh_early_platform_driver_list);
        }

        /* If the user has specified device then make sure the driver
         * gets prioritized. The driver of the last device specified on
         * command line will be put first on the list.
         */
        n = strlen(epdrv->pdrv->driver.name);
        if (buf && !strncmp(buf, epdrv->pdrv->driver.name, n)) {
                list_move(&epdrv->list, &sh_early_platform_driver_list);

                /* Allow passing parameters after device name */
                if (buf[n] == '\0' || buf[n] == ',')
                        epdrv->requested_id = -1;
                else {
                        epdrv->requested_id = simple_strtoul(&buf[n + 1],
                                                             &tmp, 10);

                        if (buf[n] != '.' || (tmp == &buf[n + 1])) {
                                epdrv->requested_id = EARLY_PLATFORM_ID_ERROR;
                                n = 0;
                        } else
                                n += strcspn(&buf[n + 1], ",") + 1;
                }

                if (buf[n] == ',')
                        n++;

                if (epdrv->bufsize) {
                        memcpy(epdrv->buffer, &buf[n],
                               min_t(int, epdrv->bufsize, strlen(&buf[n]) + 1));
                        epdrv->buffer[epdrv->bufsize - 1] = '\0';
                }
        }

        return 0;
}

/**
 * sh_early_platform_add_devices - adds a number of early platform devices
 * @devs: array of early platform devices to add
 * @num: number of early platform devices in array
 *
 * Used by early architecture code to register early platform devices and
 * their platform data.
 */
void __init sh_early_platform_add_devices(struct platform_device **devs, int num)
{
        struct device *dev;
        int i;

        /* simply add the devices to list */
        for (i = 0; i < num; i++) {
                dev = &devs[i]->dev;

                if (!dev->devres_head.next) {
                        pm_runtime_early_init(dev);
                        INIT_LIST_HEAD(&dev->devres_head);
                        list_add_tail(&dev->devres_head,
                                      &sh_early_platform_device_list);
                }
        }
}

/**
 * sh_early_platform_driver_register_all - register early platform drivers
 * @class_str: string to identify early platform driver class
 *
 * Used by architecture code to register all early platform drivers
 * for a certain class. If omitted then only early platform drivers
 * with matching kernel command line class parameters will be registered.
 */
void __init sh_early_platform_driver_register_all(char *class_str)
{
        /* The "class_str" parameter may or may not be present on the kernel
         * command line. If it is present then there may be more than one
         * matching parameter.
         *
         * Since we register our early platform drivers using early_param()
         * we need to make sure that they also get registered in the case
         * when the parameter is missing from the kernel command line.
         *
         * We use parse_early_options() to make sure the early_param() gets
         * called at least once. The early_param() may be called more than
         * once since the name of the preferred device may be specified on
         * the kernel command line. sh_early_platform_driver_register() handles
         * this case for us.
         */
        parse_early_options(class_str);
}

/**
 * sh_early_platform_match - find early platform device matching driver
 * @epdrv: early platform driver structure
 * @id: id to match against
 */
static struct platform_device * __init
sh_early_platform_match(struct sh_early_platform_driver *epdrv, int id)
{
        struct platform_device *pd;

        list_for_each_entry(pd, &sh_early_platform_device_list, dev.devres_head)
                if (platform_match(&pd->dev, &epdrv->pdrv->driver))
                        if (pd->id == id)
                                return pd;

        return NULL;
}

/**
 * sh_early_platform_left - check if early platform driver has matching devices
 * @epdrv: early platform driver structure
 * @id: return true if id or above exists
 */
static int __init sh_early_platform_left(struct sh_early_platform_driver *epdrv,
                                       int id)
{
        struct platform_device *pd;

        list_for_each_entry(pd, &sh_early_platform_device_list, dev.devres_head)
                if (platform_match(&pd->dev, &epdrv->pdrv->driver))
                        if (pd->id >= id)
                                return 1;

        return 0;
}

/**
 * sh_early_platform_driver_probe_id - probe drivers matching class_str and id
 * @class_str: string to identify early platform driver class
 * @id: id to match against
 * @nr_probe: number of platform devices to successfully probe before exiting
 */
static int __init sh_early_platform_driver_probe_id(char *class_str,
                                                 int id,
                                                 int nr_probe)
{
        struct sh_early_platform_driver *epdrv;
        struct platform_device *match;
        int match_id;
        int n = 0;
        int left = 0;

        list_for_each_entry(epdrv, &sh_early_platform_driver_list, list) {
                /* only use drivers matching our class_str */
                if (strcmp(class_str, epdrv->class_str))
                        continue;

                if (id == -2) {
                        match_id = epdrv->requested_id;
                        left = 1;

                } else {
                        match_id = id;
                        left += sh_early_platform_left(epdrv, id);

                        /* skip requested id */
                        switch (epdrv->requested_id) {
                        case EARLY_PLATFORM_ID_ERROR:
                        case EARLY_PLATFORM_ID_UNSET:
                                break;
                        default:
                                if (epdrv->requested_id == id)
                                        match_id = EARLY_PLATFORM_ID_UNSET;
                        }
                }

                switch (match_id) {
                case EARLY_PLATFORM_ID_ERROR:
                        pr_warn("%s: unable to parse %s parameter\n",
                                class_str, epdrv->pdrv->driver.name);
                        fallthrough;
                case EARLY_PLATFORM_ID_UNSET:
                        match = NULL;
                        break;
                default:
                        match = sh_early_platform_match(epdrv, match_id);
                }

                if (match) {
                        /*
                         * Set up a sensible init_name to enable
                         * dev_name() and others to be used before the
                         * rest of the driver core is initialized.
                         */
                        if (!match->dev.init_name && slab_is_available()) {
                                if (match->id != -1)
                                        match->dev.init_name =
                                                kasprintf(GFP_KERNEL, "%s.%d",
                                                          match->name,
                                                          match->id);
                                else
                                        match->dev.init_name =
                                                kasprintf(GFP_KERNEL, "%s",
                                                          match->name);

                                if (!match->dev.init_name)
                                        return -ENOMEM;
                        }

                        if (epdrv->pdrv->probe(match))
                                pr_warn("%s: unable to probe %s early.\n",
                                        class_str, match->name);
                        else
                                n++;
                }

                if (n >= nr_probe)
                        break;
        }

        if (left)
                return n;
        else
                return -ENODEV;
}

/**
 * sh_early_platform_driver_probe - probe a class of registered drivers
 * @class_str: string to identify early platform driver class
 * @nr_probe: number of platform devices to successfully probe before exiting
 * @user_only: only probe user specified early platform devices
 *
 * Used by architecture code to probe registered early platform drivers
 * within a certain class. For probe to happen a registered early platform
 * device matching a registered early platform driver is needed.
 */
int __init sh_early_platform_driver_probe(char *class_str,
                                       int nr_probe,
                                       int user_only)
{
        int k, n, i;

        n = 0;
        for (i = -2; n < nr_probe; i++) {
                k = sh_early_platform_driver_probe_id(class_str, i, nr_probe - n);

                if (k < 0)
                        break;

                n += k;

                if (user_only)
                        break;
        }

        return n;
}

/**
 * early_platform_cleanup - clean up early platform code
 */
void __init early_platform_cleanup(void)
{
        struct platform_device *pd, *pd2;

        /* clean up the devres list used to chain devices */
        list_for_each_entry_safe(pd, pd2, &sh_early_platform_device_list,
                                 dev.devres_head) {
                list_del(&pd->dev.devres_head);
                memset(&pd->dev.devres_head, 0, sizeof(pd->dev.devres_head));
        }
}