// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * PTP 1588 clock support - sysfs interface.
 *
 * Copyright (C) 2010 OMICRON electronics GmbH
 * Copyright 2021 NXP
 */
#include <linux/capability.h>
#include <linux/slab.h>

#include "ptp_private.h"

static ssize_t clock_name_show(struct device *dev,
                               struct device_attribute *attr, char *page)
{
        struct ptp_clock *ptp = dev_get_drvdata(dev);
        return sysfs_emit(page, "%s\n", ptp->info->name);
}
static DEVICE_ATTR_RO(clock_name);

static ssize_t max_phase_adjustment_show(struct device *dev,
                                         struct device_attribute *attr,
                                         char *page)
{
        struct ptp_clock *ptp = dev_get_drvdata(dev);

        return sysfs_emit(page, "%d\n", ptp->info->getmaxphase(ptp->info));
}
static DEVICE_ATTR_RO(max_phase_adjustment);

#define PTP_SHOW_INT(name, var)                                         \
static ssize_t var##_show(struct device *dev,                           \
                           struct device_attribute *attr, char *page)   \
{                                                                       \
        struct ptp_clock *ptp = dev_get_drvdata(dev);                   \
        return sysfs_emit(page, "%d\n", ptp->info->var);        \
}                                                                       \
static DEVICE_ATTR(name, 0444, var##_show, NULL);

PTP_SHOW_INT(max_adjustment, max_adj);
PTP_SHOW_INT(n_alarms, n_alarm);
PTP_SHOW_INT(n_external_timestamps, n_ext_ts);
PTP_SHOW_INT(n_periodic_outputs, n_per_out);
PTP_SHOW_INT(n_programmable_pins, n_pins);
PTP_SHOW_INT(pps_available, pps);

static ssize_t extts_enable_store(struct device *dev,
                                  struct device_attribute *attr,
                                  const char *buf, size_t count)
{
        struct ptp_clock *ptp = dev_get_drvdata(dev);
        struct ptp_clock_info *ops = ptp->info;
        struct ptp_clock_request req = { .type = PTP_CLK_REQ_EXTTS };
        int cnt, enable;
        int err = -EINVAL;

        cnt = sscanf(buf, "%u %d", &req.extts.index, &enable);
        if (cnt != 2)
                goto out;
        if (req.extts.index >= ops->n_ext_ts)
                goto out;

        err = ops->enable(ops, &req, enable ? 1 : 0);
        if (err)
                goto out;

        return count;
out:
        return err;
}
static DEVICE_ATTR(extts_enable, 0220, NULL, extts_enable_store);

static ssize_t extts_fifo_show(struct device *dev,
                               struct device_attribute *attr, char *page)
{
        struct ptp_clock *ptp = dev_get_drvdata(dev);
        struct timestamp_event_queue *queue;
        struct ptp_extts_event event;
        unsigned long flags;
        size_t qcnt;
        int cnt = 0;

        cnt = list_count_nodes(&ptp->tsevqs);
        if (cnt <= 0)
                goto out;

        /* The sysfs fifo will always draw from the fist queue */
        queue = list_first_entry(&ptp->tsevqs, struct timestamp_event_queue,
                                 qlist);

        memset(&event, 0, sizeof(event));
        spin_lock_irqsave(&queue->lock, flags);
        qcnt = queue_cnt(queue);
        if (qcnt) {
                event = queue->buf[queue->head];
                /* Paired with READ_ONCE() in queue_cnt() */
                WRITE_ONCE(queue->head, (queue->head + 1) % PTP_MAX_TIMESTAMPS);
        }
        spin_unlock_irqrestore(&queue->lock, flags);

        if (!qcnt)
                goto out;

        cnt = sysfs_emit(page, "%u %lld %u\n",
                         event.index, event.t.sec, event.t.nsec);
out:
        return cnt;
}
static DEVICE_ATTR(fifo, 0444, extts_fifo_show, NULL);

static ssize_t period_store(struct device *dev,
                            struct device_attribute *attr,
                            const char *buf, size_t count)
{
        struct ptp_clock *ptp = dev_get_drvdata(dev);
        struct ptp_clock_info *ops = ptp->info;
        struct ptp_clock_request req = { .type = PTP_CLK_REQ_PEROUT };
        int cnt, enable, err = -EINVAL;

        cnt = sscanf(buf, "%u %lld %u %lld %u", &req.perout.index,
                     &req.perout.start.sec, &req.perout.start.nsec,
                     &req.perout.period.sec, &req.perout.period.nsec);
        if (cnt != 5)
                goto out;
        if (req.perout.index >= ops->n_per_out)
                goto out;

        enable = req.perout.period.sec || req.perout.period.nsec;
        err = ops->enable(ops, &req, enable);
        if (err)
                goto out;

        return count;
out:
        return err;
}
static DEVICE_ATTR(period, 0220, NULL, period_store);

static ssize_t pps_enable_store(struct device *dev,
                                struct device_attribute *attr,
                                const char *buf, size_t count)
{
        struct ptp_clock *ptp = dev_get_drvdata(dev);
        struct ptp_clock_info *ops = ptp->info;
        struct ptp_clock_request req = { .type = PTP_CLK_REQ_PPS };
        int cnt, enable;
        int err = -EINVAL;

        if (!capable(CAP_SYS_TIME))
                return -EPERM;

        cnt = sscanf(buf, "%d", &enable);
        if (cnt != 1)
                goto out;

        err = ops->enable(ops, &req, enable ? 1 : 0);
        if (err)
                goto out;

        return count;
out:
        return err;
}
static DEVICE_ATTR(pps_enable, 0220, NULL, pps_enable_store);

static int unregister_vclock(struct device *dev, void *data)
{
        struct ptp_clock *ptp = dev_get_drvdata(dev);
        struct ptp_clock_info *info = ptp->info;
        struct ptp_vclock *vclock;
        u32 *num = data;

        vclock = info_to_vclock(info);
        dev_info(dev->parent, "delete virtual clock ptp%d\n",
                 vclock->clock->index);

        ptp_vclock_unregister(vclock);
        (*num)--;

        /* For break. Not error. */
        if (*num == 0)
                return -EINVAL;

        return 0;
}

static ssize_t n_vclocks_show(struct device *dev,
                              struct device_attribute *attr, char *page)
{
        struct ptp_clock *ptp = dev_get_drvdata(dev);
        ssize_t size;

        if (mutex_lock_interruptible(&ptp->n_vclocks_mux))
                return -ERESTARTSYS;

        size = sysfs_emit(page, "%u\n", ptp->n_vclocks);

        mutex_unlock(&ptp->n_vclocks_mux);

        return size;
}

static ssize_t n_vclocks_store(struct device *dev,
                               struct device_attribute *attr,
                               const char *buf, size_t count)
{
        struct ptp_clock *ptp = dev_get_drvdata(dev);
        struct ptp_vclock *vclock;
        int err = -EINVAL;
        u32 num, i;

        if (kstrtou32(buf, 0, &num))
                return err;

        if (mutex_lock_interruptible(&ptp->n_vclocks_mux))
                return -ERESTARTSYS;

        if (num > ptp->max_vclocks) {
                dev_err(dev, "max value is %d\n", ptp->max_vclocks);
                goto out;
        }

        /* Need to create more vclocks */
        if (num > ptp->n_vclocks) {
                for (i = 0; i < num - ptp->n_vclocks; i++) {
                        vclock = ptp_vclock_register(ptp);
                        if (!vclock)
                                goto out;

                        *(ptp->vclock_index + ptp->n_vclocks + i) =
                                vclock->clock->index;

                        dev_info(dev, "new virtual clock ptp%d\n",
                                 vclock->clock->index);
                }
        }

        /* Need to delete vclocks */
        if (num < ptp->n_vclocks) {
                i = ptp->n_vclocks - num;
                device_for_each_child_reverse(dev, &i,
                                              unregister_vclock);

                for (i = 1; i <= ptp->n_vclocks - num; i++)
                        *(ptp->vclock_index + ptp->n_vclocks - i) = -1;
        }

        /* Need to inform about changed physical clock behavior */
        if (!ptp->has_cycles) {
                if (num == 0)
                        dev_info(dev, "only physical clock in use now\n");
                else
                        dev_info(dev, "guarantee physical clock free running\n");
        }

        ptp->n_vclocks = num;
        mutex_unlock(&ptp->n_vclocks_mux);

        return count;
out:
        mutex_unlock(&ptp->n_vclocks_mux);
        return err;
}
static DEVICE_ATTR_RW(n_vclocks);

static ssize_t max_vclocks_show(struct device *dev,
                                struct device_attribute *attr, char *page)
{
        struct ptp_clock *ptp = dev_get_drvdata(dev);
        ssize_t size;

        size = sysfs_emit(page, "%u\n", ptp->max_vclocks);

        return size;
}

static ssize_t max_vclocks_store(struct device *dev,
                                 struct device_attribute *attr,
                                 const char *buf, size_t count)
{
        struct ptp_clock *ptp = dev_get_drvdata(dev);
        unsigned int *vclock_index;
        int err = -EINVAL;
        size_t size;
        u32 max;

        if (kstrtou32(buf, 0, &max) || max == 0 || max > PTP_MAX_VCLOCKS_LIMIT)
                return -EINVAL;

        if (max == ptp->max_vclocks)
                return count;

        if (mutex_lock_interruptible(&ptp->n_vclocks_mux))
                return -ERESTARTSYS;

        if (max < ptp->n_vclocks)
                goto out;

        vclock_index = kcalloc(max, sizeof(int), GFP_KERNEL);
        if (!vclock_index) {
                err = -ENOMEM;
                goto out;
        }

        size = sizeof(int) * ptp->n_vclocks;
        memcpy(vclock_index, ptp->vclock_index, size);

        kfree(ptp->vclock_index);
        ptp->vclock_index = vclock_index;
        ptp->max_vclocks = max;

        mutex_unlock(&ptp->n_vclocks_mux);

        return count;
out:
        mutex_unlock(&ptp->n_vclocks_mux);
        return err;
}
static DEVICE_ATTR_RW(max_vclocks);

static struct attribute *ptp_attrs[] = {
        &dev_attr_clock_name.attr,

        &dev_attr_max_adjustment.attr,
        &dev_attr_max_phase_adjustment.attr,
        &dev_attr_n_alarms.attr,
        &dev_attr_n_external_timestamps.attr,
        &dev_attr_n_periodic_outputs.attr,
        &dev_attr_n_programmable_pins.attr,
        &dev_attr_pps_available.attr,

        &dev_attr_extts_enable.attr,
        &dev_attr_fifo.attr,
        &dev_attr_period.attr,
        &dev_attr_pps_enable.attr,
        &dev_attr_n_vclocks.attr,
        &dev_attr_max_vclocks.attr,
        NULL
};

static umode_t ptp_is_attribute_visible(struct kobject *kobj,
                                        struct attribute *attr, int n)
{
        struct device *dev = kobj_to_dev(kobj);
        struct ptp_clock *ptp = dev_get_drvdata(dev);
        struct ptp_clock_info *info = ptp->info;
        umode_t mode = attr->mode;

        if (attr == &dev_attr_extts_enable.attr ||
            attr == &dev_attr_fifo.attr) {
                if (!info->n_ext_ts)
                        mode = 0;
        } else if (attr == &dev_attr_period.attr) {
                if (!info->n_per_out)
                        mode = 0;
        } else if (attr == &dev_attr_pps_enable.attr) {
                if (!info->pps)
                        mode = 0;
        } else if (attr == &dev_attr_n_vclocks.attr ||
                   attr == &dev_attr_max_vclocks.attr) {
                if (ptp->is_virtual_clock)
                        mode = 0;
        } else if (attr == &dev_attr_max_phase_adjustment.attr) {
                if (!info->adjphase || !info->getmaxphase)
                        mode = 0;
        }

        return mode;
}

static const struct attribute_group ptp_group = {
        .is_visible     = ptp_is_attribute_visible,
        .attrs          = ptp_attrs,
};

const struct attribute_group *ptp_groups[] = {
        &ptp_group,
        NULL
};

static int ptp_pin_name2index(struct ptp_clock *ptp, const char *name)
{
        int i;
        for (i = 0; i < ptp->info->n_pins; i++) {
                if (!strcmp(ptp->info->pin_config[i].name, name))
                        return i;
        }
        return -1;
}

static ssize_t ptp_pin_show(struct device *dev, struct device_attribute *attr,
                            char *page)
{
        struct ptp_clock *ptp = dev_get_drvdata(dev);
        unsigned int func, chan;
        int index;

        index = ptp_pin_name2index(ptp, attr->attr.name);
        if (index < 0)
                return -EINVAL;

        if (mutex_lock_interruptible(&ptp->pincfg_mux))
                return -ERESTARTSYS;

        func = ptp->info->pin_config[index].func;
        chan = ptp->info->pin_config[index].chan;

        mutex_unlock(&ptp->pincfg_mux);

        return sysfs_emit(page, "%u %u\n", func, chan);
}

static ssize_t ptp_pin_store(struct device *dev, struct device_attribute *attr,
                             const char *buf, size_t count)
{
        struct ptp_clock *ptp = dev_get_drvdata(dev);
        unsigned int func, chan;
        int cnt, err, index;

        cnt = sscanf(buf, "%u %u", &func, &chan);
        if (cnt != 2)
                return -EINVAL;

        index = ptp_pin_name2index(ptp, attr->attr.name);
        if (index < 0)
                return -EINVAL;

        if (mutex_lock_interruptible(&ptp->pincfg_mux))
                return -ERESTARTSYS;
        err = ptp_set_pinfunc(ptp, index, func, chan);
        mutex_unlock(&ptp->pincfg_mux);
        if (err)
                return err;

        return count;
}

int ptp_populate_pin_groups(struct ptp_clock *ptp)
{
        struct ptp_clock_info *info = ptp->info;
        int err = -ENOMEM, i, n_pins = info->n_pins;

        if (!n_pins)
                return 0;

        ptp->pin_dev_attr = kzalloc_objs(*ptp->pin_dev_attr, n_pins);
        if (!ptp->pin_dev_attr)
                goto no_dev_attr;

        ptp->pin_attr = kzalloc_objs(*ptp->pin_attr, 1 + n_pins);
        if (!ptp->pin_attr)
                goto no_pin_attr;

        for (i = 0; i < n_pins; i++) {
                struct device_attribute *da = &ptp->pin_dev_attr[i];
                sysfs_attr_init(&da->attr);
                da->attr.name = info->pin_config[i].name;
                da->attr.mode = 0644;
                da->show = ptp_pin_show;
                da->store = ptp_pin_store;
                ptp->pin_attr[i] = &da->attr;
        }

        ptp->pin_attr_group.name = "pins";
        ptp->pin_attr_group.attrs = ptp->pin_attr;

        ptp->pin_attr_groups[0] = &ptp->pin_attr_group;

        return 0;

no_pin_attr:
        kfree(ptp->pin_dev_attr);
no_dev_attr:
        return err;
}

void ptp_cleanup_pin_groups(struct ptp_clock *ptp)
{
        kfree(ptp->pin_attr);
        kfree(ptp->pin_dev_attr);
}