// SPDX-License-Identifier: GPL-2.0
/*
 * Provides code common for host and device side USB.
 *
 * If either host side (ie. CONFIG_USB=y) or device side USB stack
 * (ie. CONFIG_USB_GADGET=y) is compiled in the kernel, this module is
 * compiled-in as well.  Otherwise, if either of the two stacks is
 * compiled as module, this file is compiled as module as well.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/usb/ch9.h>
#include <linux/usb/of.h>
#include <linux/usb/otg.h>
#include <linux/of_platform.h>
#include <linux/debugfs.h>
#include "common.h"

static const char *const ep_type_names[] = {
        [USB_ENDPOINT_XFER_CONTROL] = "ctrl",
        [USB_ENDPOINT_XFER_ISOC] = "isoc",
        [USB_ENDPOINT_XFER_BULK] = "bulk",
        [USB_ENDPOINT_XFER_INT] = "intr",
};

/**
 * usb_ep_type_string() - Returns human readable-name of the endpoint type.
 * @ep_type: The endpoint type to return human-readable name for.  If it's not
 *   any of the types: USB_ENDPOINT_XFER_{CONTROL, ISOC, BULK, INT},
 *   usually got by usb_endpoint_type(), the string 'unknown' will be returned.
 */
const char *usb_ep_type_string(int ep_type)
{
        if (ep_type < 0 || ep_type >= ARRAY_SIZE(ep_type_names))
                return "unknown";

        return ep_type_names[ep_type];
}
EXPORT_SYMBOL_GPL(usb_ep_type_string);

/**
 * usb_otg_state_string() - returns human readable name of OTG state.
 * @state: the OTG state to return the human readable name of. If it's not
 *    any of the states defined in usb_otg_state enum, 'UNDEFINED' will be
 *    returned.
 */
const char *usb_otg_state_string(enum usb_otg_state state)
{
        static const char *const names[] = {
                [OTG_STATE_A_IDLE] = "a_idle",
                [OTG_STATE_A_WAIT_VRISE] = "a_wait_vrise",
                [OTG_STATE_A_WAIT_BCON] = "a_wait_bcon",
                [OTG_STATE_A_HOST] = "a_host",
                [OTG_STATE_A_SUSPEND] = "a_suspend",
                [OTG_STATE_A_PERIPHERAL] = "a_peripheral",
                [OTG_STATE_A_WAIT_VFALL] = "a_wait_vfall",
                [OTG_STATE_A_VBUS_ERR] = "a_vbus_err",
                [OTG_STATE_B_IDLE] = "b_idle",
                [OTG_STATE_B_SRP_INIT] = "b_srp_init",
                [OTG_STATE_B_PERIPHERAL] = "b_peripheral",
                [OTG_STATE_B_WAIT_ACON] = "b_wait_acon",
                [OTG_STATE_B_HOST] = "b_host",
        };

        if (state < 0 || state >= ARRAY_SIZE(names))
                return "UNDEFINED";

        return names[state];
}
EXPORT_SYMBOL_GPL(usb_otg_state_string);

static const char *const speed_names[] = {
        [USB_SPEED_UNKNOWN] = "UNKNOWN",
        [USB_SPEED_LOW] = "low-speed",
        [USB_SPEED_FULL] = "full-speed",
        [USB_SPEED_HIGH] = "high-speed",
        [USB_SPEED_WIRELESS] = "wireless",
        [USB_SPEED_SUPER] = "super-speed",
        [USB_SPEED_SUPER_PLUS] = "super-speed-plus",
};

static const char *const ssp_rate[] = {
        [USB_SSP_GEN_UNKNOWN] = "UNKNOWN",
        [USB_SSP_GEN_2x1] = "super-speed-plus-gen2x1",
        [USB_SSP_GEN_1x2] = "super-speed-plus-gen1x2",
        [USB_SSP_GEN_2x2] = "super-speed-plus-gen2x2",
};

/**
 * usb_speed_string() - Returns human readable-name of the speed.
 * @speed: The speed to return human-readable name for.  If it's not
 *   any of the speeds defined in usb_device_speed enum, string for
 *   USB_SPEED_UNKNOWN will be returned.
 */
const char *usb_speed_string(enum usb_device_speed speed)
{
        if (speed < 0 || speed >= ARRAY_SIZE(speed_names))
                speed = USB_SPEED_UNKNOWN;
        return speed_names[speed];
}
EXPORT_SYMBOL_GPL(usb_speed_string);

/**
 * usb_get_maximum_speed - Get maximum requested speed for a given USB
 * controller.
 * @dev: Pointer to the given USB controller device
 *
 * The function gets the maximum speed string from property "maximum-speed",
 * and returns the corresponding enum usb_device_speed.
 */
enum usb_device_speed usb_get_maximum_speed(struct device *dev)
{
        const char *p = "maximum-speed";
        int ret;

        ret = device_property_match_property_string(dev, p, ssp_rate, ARRAY_SIZE(ssp_rate));
        if (ret > 0)
                return USB_SPEED_SUPER_PLUS;

        ret = device_property_match_property_string(dev, p, speed_names, ARRAY_SIZE(speed_names));
        if (ret > 0)
                return ret;

        return USB_SPEED_UNKNOWN;
}
EXPORT_SYMBOL_GPL(usb_get_maximum_speed);

/**
 * usb_get_maximum_ssp_rate - Get the signaling rate generation and lane count
 *      of a SuperSpeed Plus capable device.
 * @dev: Pointer to the given USB controller device
 *
 * If the string from "maximum-speed" property is super-speed-plus-genXxY where
 * 'X' is the generation number and 'Y' is the number of lanes, then this
 * function returns the corresponding enum usb_ssp_rate.
 */
enum usb_ssp_rate usb_get_maximum_ssp_rate(struct device *dev)
{
        const char *maximum_speed;
        int ret;

        ret = device_property_read_string(dev, "maximum-speed", &maximum_speed);
        if (ret < 0)
                return USB_SSP_GEN_UNKNOWN;

        ret = match_string(ssp_rate, ARRAY_SIZE(ssp_rate), maximum_speed);
        return (ret < 0) ? USB_SSP_GEN_UNKNOWN : ret;
}
EXPORT_SYMBOL_GPL(usb_get_maximum_ssp_rate);

/**
 * usb_state_string - Returns human readable name for the state.
 * @state: The state to return a human-readable name for. If it's not
 *      any of the states devices in usb_device_state_string enum,
 *      the string UNKNOWN will be returned.
 */
const char *usb_state_string(enum usb_device_state state)
{
        static const char *const names[] = {
                [USB_STATE_NOTATTACHED] = "not attached",
                [USB_STATE_ATTACHED] = "attached",
                [USB_STATE_POWERED] = "powered",
                [USB_STATE_RECONNECTING] = "reconnecting",
                [USB_STATE_UNAUTHENTICATED] = "unauthenticated",
                [USB_STATE_DEFAULT] = "default",
                [USB_STATE_ADDRESS] = "addressed",
                [USB_STATE_CONFIGURED] = "configured",
                [USB_STATE_SUSPENDED] = "suspended",
        };

        if (state < 0 || state >= ARRAY_SIZE(names))
                return "UNKNOWN";

        return names[state];
}
EXPORT_SYMBOL_GPL(usb_state_string);

static const char *const usb_dr_modes[] = {
        [USB_DR_MODE_UNKNOWN]           = "",
        [USB_DR_MODE_HOST]              = "host",
        [USB_DR_MODE_PERIPHERAL]        = "peripheral",
        [USB_DR_MODE_OTG]               = "otg",
};

/**
 * usb_get_dr_mode_from_string() - Get dual role mode for given string
 * @str: String to find the corresponding dual role mode for
 *
 * This function performs a lookup for the given string and returns the
 * corresponding enum usb_dr_mode. If no match for the string could be found,
 * 'USB_DR_MODE_UNKNOWN' is returned.
 */
static enum usb_dr_mode usb_get_dr_mode_from_string(const char *str)
{
        int ret;

        ret = match_string(usb_dr_modes, ARRAY_SIZE(usb_dr_modes), str);
        return (ret < 0) ? USB_DR_MODE_UNKNOWN : ret;
}

enum usb_dr_mode usb_get_dr_mode(struct device *dev)
{
        const char *dr_mode;
        int err;

        err = device_property_read_string(dev, "dr_mode", &dr_mode);
        if (err < 0)
                return USB_DR_MODE_UNKNOWN;

        return usb_get_dr_mode_from_string(dr_mode);
}
EXPORT_SYMBOL_GPL(usb_get_dr_mode);

/**
 * usb_get_role_switch_default_mode - Get default mode for given device
 * @dev: Pointer to the given device
 *
 * The function gets string from property 'role-switch-default-mode',
 * and returns the corresponding enum usb_dr_mode.
 */
enum usb_dr_mode usb_get_role_switch_default_mode(struct device *dev)
{
        const char *str;
        int ret;

        ret = device_property_read_string(dev, "role-switch-default-mode", &str);
        if (ret < 0)
                return USB_DR_MODE_UNKNOWN;

        return usb_get_dr_mode_from_string(str);
}
EXPORT_SYMBOL_GPL(usb_get_role_switch_default_mode);

/**
 * usb_decode_interval - Decode bInterval into the time expressed in 1us unit
 * @epd: The descriptor of the endpoint
 * @speed: The speed that the endpoint works as
 *
 * Function returns the interval expressed in 1us unit for servicing
 * endpoint for data transfers.
 */
unsigned int usb_decode_interval(const struct usb_endpoint_descriptor *epd,
                                 enum usb_device_speed speed)
{
        unsigned int interval = 0;

        switch (usb_endpoint_type(epd)) {
        case USB_ENDPOINT_XFER_CONTROL:
                /* uframes per NAK */
                if (speed == USB_SPEED_HIGH)
                        interval = epd->bInterval;
                break;
        case USB_ENDPOINT_XFER_ISOC:
                interval = 1 << (epd->bInterval - 1);
                break;
        case USB_ENDPOINT_XFER_BULK:
                /* uframes per NAK */
                if (speed == USB_SPEED_HIGH && usb_endpoint_dir_out(epd))
                        interval = epd->bInterval;
                break;
        case USB_ENDPOINT_XFER_INT:
                if (speed >= USB_SPEED_HIGH)
                        interval = 1 << (epd->bInterval - 1);
                else
                        interval = epd->bInterval;
                break;
        }

        interval *= (speed >= USB_SPEED_HIGH) ? 125 : 1000;

        return interval;
}
EXPORT_SYMBOL_GPL(usb_decode_interval);

#ifdef CONFIG_OF
/**
 * of_usb_get_dr_mode_by_phy - Get dual role mode for the controller device
 * which is associated with the given phy device_node
 * @np: Pointer to the given phy device_node
 * @arg0: phandle args[0] for phy's with #phy-cells >= 1, or -1 for
 *        phys which do not have phy-cells
 *
 * In dts a usb controller associates with phy devices.  The function gets
 * the string from property 'dr_mode' of the controller associated with the
 * given phy device node, and returns the correspondig enum usb_dr_mode.
 */
enum usb_dr_mode of_usb_get_dr_mode_by_phy(struct device_node *np, int arg0)
{
        struct device_node *controller;
        struct of_phandle_args args;
        const char *dr_mode;
        int index;
        int err;

        for_each_node_with_property(controller, "phys") {
                if (!of_device_is_available(controller))
                        continue;
                index = 0;
                do {
                        if (arg0 == -1) {
                                args.np = of_parse_phandle(controller, "phys",
                                                        index);
                                args.args_count = 0;
                        } else {
                                err = of_parse_phandle_with_args(controller,
                                                        "phys", "#phy-cells",
                                                        index, &args);
                                if (err)
                                        break;
                        }

                        of_node_put(args.np);
                        if (args.np == np && (args.args_count == 0 ||
                                              args.args[0] == arg0))
                                goto finish;
                        index++;
                } while (args.np);
        }

finish:
        err = of_property_read_string(controller, "dr_mode", &dr_mode);
        of_node_put(controller);

        if (err < 0)
                return USB_DR_MODE_UNKNOWN;

        return usb_get_dr_mode_from_string(dr_mode);
}
EXPORT_SYMBOL_GPL(of_usb_get_dr_mode_by_phy);

/**
 * of_usb_host_tpl_support - to get if Targeted Peripheral List is supported
 * for given targeted hosts (non-PC hosts)
 * @np: Pointer to the given device_node
 *
 * The function gets if the targeted hosts support TPL or not
 */
bool of_usb_host_tpl_support(struct device_node *np)
{
        return of_property_read_bool(np, "tpl-support");
}
EXPORT_SYMBOL_GPL(of_usb_host_tpl_support);

/**
 * of_usb_update_otg_caps - to update usb otg capabilities according to
 * the passed properties in DT.
 * @np: Pointer to the given device_node
 * @otg_caps: Pointer to the target usb_otg_caps to be set
 *
 * The function updates the otg capabilities
 */
int of_usb_update_otg_caps(struct device_node *np,
                        struct usb_otg_caps *otg_caps)
{
        u32 otg_rev;

        if (!otg_caps)
                return -EINVAL;

        if (!of_property_read_u32(np, "otg-rev", &otg_rev)) {
                switch (otg_rev) {
                case 0x0100:
                case 0x0120:
                case 0x0130:
                case 0x0200:
                        /* Choose the lesser one if it's already been set */
                        if (otg_caps->otg_rev)
                                otg_caps->otg_rev = min_t(u16, otg_rev,
                                                        otg_caps->otg_rev);
                        else
                                otg_caps->otg_rev = otg_rev;
                        break;
                default:
                        pr_err("%pOF: unsupported otg-rev: 0x%x\n",
                                                np, otg_rev);
                        return -EINVAL;
                }
        } else {
                /*
                 * otg-rev is mandatory for otg properties, if not passed
                 * we set it to be 0 and assume it's a legacy otg device.
                 * Non-dt platform can set it afterwards.
                 */
                otg_caps->otg_rev = 0;
        }

        if (of_property_read_bool(np, "hnp-disable"))
                otg_caps->hnp_support = false;
        if (of_property_read_bool(np, "srp-disable"))
                otg_caps->srp_support = false;
        if (of_property_read_bool(np, "adp-disable") ||
                                (otg_caps->otg_rev < 0x0200))
                otg_caps->adp_support = false;

        return 0;
}
EXPORT_SYMBOL_GPL(of_usb_update_otg_caps);

/**
 * usb_of_get_companion_dev - Find the companion device
 * @dev: the device pointer to find a companion
 *
 * Find the companion device from platform bus.
 *
 * Takes a reference to the returned struct device which needs to be dropped
 * after use.
 *
 * Return: On success, a pointer to the companion device, %NULL on failure.
 */
struct device *usb_of_get_companion_dev(struct device *dev)
{
        struct device_node *node;
        struct platform_device *pdev = NULL;

        node = of_parse_phandle(dev->of_node, "companion", 0);
        if (node)
                pdev = of_find_device_by_node(node);

        of_node_put(node);

        return pdev ? &pdev->dev : NULL;
}
EXPORT_SYMBOL_GPL(usb_of_get_companion_dev);
#endif

struct dentry *usb_debug_root;
EXPORT_SYMBOL_GPL(usb_debug_root);

DEFINE_MUTEX(usb_dynids_lock);
EXPORT_SYMBOL_GPL(usb_dynids_lock);

static int __init usb_common_init(void)
{
        usb_debug_root = debugfs_create_dir("usb", NULL);
        ledtrig_usb_init();
        return 0;
}

static void __exit usb_common_exit(void)
{
        ledtrig_usb_exit();
        debugfs_remove_recursive(usb_debug_root);
}

subsys_initcall(usb_common_init);
module_exit(usb_common_exit);

MODULE_DESCRIPTION("Common code for host and device side USB");
MODULE_LICENSE("GPL");