// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (C) 2007 by Alan Stern
 */

/* this file is part of ehci-hcd.c */


/* Display the ports dedicated to the companion controller */
static ssize_t companion_show(struct device *dev,
                              struct device_attribute *attr,
                              char *buf)
{
        struct ehci_hcd         *ehci;
        int                     nports, index;
        int                     len = 0;

        ehci = hcd_to_ehci(dev_get_drvdata(dev));
        nports = HCS_N_PORTS(ehci->hcs_params);

        for (index = 0; index < nports; ++index) {
                if (test_bit(index, &ehci->companion_ports))
                        len += sysfs_emit_at(buf, len, "%d\n", index + 1);
        }
        return len;
}

/*
 * Dedicate or undedicate a port to the companion controller.
 * Syntax is "[-]portnum", where a leading '-' sign means
 * return control of the port to the EHCI controller.
 */
static ssize_t companion_store(struct device *dev,
                               struct device_attribute *attr,
                               const char *buf, size_t count)
{
        struct ehci_hcd         *ehci;
        int                     portnum, new_owner;

        ehci = hcd_to_ehci(dev_get_drvdata(dev));
        new_owner = PORT_OWNER;         /* Owned by companion */
        if (sscanf(buf, "%d", &portnum) != 1)
                return -EINVAL;
        if (portnum < 0) {
                portnum = - portnum;
                new_owner = 0;          /* Owned by EHCI */
        }
        if (portnum <= 0 || portnum > HCS_N_PORTS(ehci->hcs_params))
                return -ENOENT;
        portnum--;
        if (new_owner)
                set_bit(portnum, &ehci->companion_ports);
        else
                clear_bit(portnum, &ehci->companion_ports);
        set_owner(ehci, portnum, new_owner);
        return count;
}
static DEVICE_ATTR_RW(companion);


/*
 * Display / Set uframe_periodic_max
 */
static ssize_t uframe_periodic_max_show(struct device *dev,
                                        struct device_attribute *attr,
                                        char *buf)
{
        struct ehci_hcd         *ehci;

        ehci = hcd_to_ehci(dev_get_drvdata(dev));
        return sysfs_emit(buf, "%d\n", ehci->uframe_periodic_max);
}


static ssize_t uframe_periodic_max_store(struct device *dev,
                                        struct device_attribute *attr,
                                        const char *buf, size_t count)
{
        struct ehci_hcd         *ehci;
        unsigned                uframe_periodic_max;
        unsigned                uframe;
        unsigned long           flags;
        ssize_t                 ret;

        ehci = hcd_to_ehci(dev_get_drvdata(dev));
        if (kstrtouint(buf, 0, &uframe_periodic_max) < 0)
                return -EINVAL;

        if (uframe_periodic_max < 100 || uframe_periodic_max >= 125) {
                ehci_info(ehci, "rejecting invalid request for "
                                "uframe_periodic_max=%u\n", uframe_periodic_max);
                return -EINVAL;
        }

        ret = -EINVAL;

        /*
         * lock, so that our checking does not race with possible periodic
         * bandwidth allocation through submitting new urbs.
         */
        spin_lock_irqsave (&ehci->lock, flags);

        /*
         * for request to decrease max periodic bandwidth, we have to check
         * to see whether the decrease is possible.
         */
        if (uframe_periodic_max < ehci->uframe_periodic_max) {
                u8              allocated_max = 0;

                for (uframe = 0; uframe < EHCI_BANDWIDTH_SIZE; ++uframe)
                        allocated_max = max(allocated_max,
                                        ehci->bandwidth[uframe]);

                if (allocated_max > uframe_periodic_max) {
                        ehci_info(ehci,
                                "cannot decrease uframe_periodic_max because "
                                "periodic bandwidth is already allocated "
                                "(%u > %u)\n",
                                allocated_max, uframe_periodic_max);
                        goto out_unlock;
                }
        }

        /* increasing is always ok */

        ehci_info(ehci, "setting max periodic bandwidth to %u%% "
                        "(== %u usec/uframe)\n",
                        100*uframe_periodic_max/125, uframe_periodic_max);

        if (uframe_periodic_max != 100)
                ehci_warn(ehci, "max periodic bandwidth set is non-standard\n");

        ehci->uframe_periodic_max = uframe_periodic_max;
        ret = count;

out_unlock:
        spin_unlock_irqrestore (&ehci->lock, flags);
        return ret;
}
static DEVICE_ATTR_RW(uframe_periodic_max);


static inline int create_sysfs_files(struct ehci_hcd *ehci)
{
        struct device   *controller = ehci_to_hcd(ehci)->self.controller;
        int     i = 0;

        /* with integrated TT there is no companion! */
        if (!ehci_is_TDI(ehci))
                i = device_create_file(controller, &dev_attr_companion);
        if (i)
                goto out;

        i = device_create_file(controller, &dev_attr_uframe_periodic_max);
out:
        return i;
}

static inline void remove_sysfs_files(struct ehci_hcd *ehci)
{
        struct device   *controller = ehci_to_hcd(ehci)->self.controller;

        /* with integrated TT there is no companion! */
        if (!ehci_is_TDI(ehci))
                device_remove_file(controller, &dev_attr_companion);

        device_remove_file(controller, &dev_attr_uframe_periodic_max);
}