// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * driver for the SAA7146 based AV110 cards
 * - CA and CI stuff
 *
 * Copyright (C) 1999-2002 Ralph  Metzler
 *                       & Marcus Metzler for convergence integrated media GmbH
 *
 * originally based on code by:
 * Copyright (C) 1998,1999 Christian Theiss <mistert@rz.fh-augsburg.de>
 *
 * the project's page is at https://linuxtv.org
 */

#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/delay.h>
#include <linux/fs.h>
#include <linux/timer.h>
#include <linux/poll.h>
#include <linux/gfp.h>

#include "av7110.h"
#include "av7110_hw.h"
#include "av7110_ca.h"

void CI_handle(struct av7110 *av7110, u8 *data, u16 len)
{
        unsigned int slot_num;

        dprintk(8, "av7110:%p\n", av7110);

        if (len < 3)
                return;
        switch (data[0]) {
        case CI_MSG_CI_INFO:
                if (data[2] != 1 && data[2] != MAX_CI_SLOTS)
                        break;

                slot_num = array_index_nospec(data[2] - 1, MAX_CI_SLOTS);

                switch (data[1]) {
                case 0:
                        av7110->ci_slot[slot_num].flags = 0;
                        break;
                case 1:
                        av7110->ci_slot[slot_num].flags |= CA_CI_MODULE_PRESENT;
                        break;
                case 2:
                        av7110->ci_slot[slot_num].flags |= CA_CI_MODULE_READY;
                        break;
                }
                break;
        case CI_SWITCH_PRG_REPLY:
                //av7110->ci_stat=data[1];
                break;
        default:
                break;
        }
}

void ci_get_data(struct dvb_ringbuffer *cibuf, u8 *data, int len)
{
        if (dvb_ringbuffer_free(cibuf) < len + 2)
                return;

        DVB_RINGBUFFER_WRITE_BYTE(cibuf, len >> 8);
        DVB_RINGBUFFER_WRITE_BYTE(cibuf, len & 0xff);
        dvb_ringbuffer_write(cibuf, data, len);
        wake_up_interruptible(&cibuf->queue);
}

/******************************************************************************
 * CI link layer file ops
 ******************************************************************************/

static int ci_ll_init(struct dvb_ringbuffer *cirbuf, struct dvb_ringbuffer *ciwbuf, int size)
{
        struct dvb_ringbuffer *tab[] = { cirbuf, ciwbuf, NULL }, **p;
        void *data;

        for (p = tab; *p; p++) {
                data = vmalloc(size);
                if (!data) {
                        while (p-- != tab) {
                                vfree(p[0]->data);
                                p[0]->data = NULL;
                        }
                        return -ENOMEM;
                }
                dvb_ringbuffer_init(*p, data, size);
        }
        return 0;
}

static void ci_ll_flush(struct dvb_ringbuffer *cirbuf, struct dvb_ringbuffer *ciwbuf)
{
        dvb_ringbuffer_flush_spinlock_wakeup(cirbuf);
        dvb_ringbuffer_flush_spinlock_wakeup(ciwbuf);
}

static void ci_ll_release(struct dvb_ringbuffer *cirbuf, struct dvb_ringbuffer *ciwbuf)
{
        vfree(cirbuf->data);
        cirbuf->data = NULL;
        vfree(ciwbuf->data);
        ciwbuf->data = NULL;
}

static int ci_ll_reset(struct dvb_ringbuffer *cibuf, struct file *file,
                       int slots, struct ca_slot_info *slot)
{
        int i;
        int len = 0;
        u8 msg[8] = { 0x00, 0x06, 0x00, 0x00, 0xff, 0x02, 0x00, 0x00 };

        for (i = 0; i < 2; i++) {
                if (slots & (1 << i))
                        len += 8;
        }

        if (dvb_ringbuffer_free(cibuf) < len)
                return -EBUSY;

        for (i = 0; i < 2; i++) {
                if (slots & (1 << i)) {
                        msg[2] = i;
                        dvb_ringbuffer_write(cibuf, msg, 8);
                        slot[i].flags = 0;
                }
        }

        return 0;
}

static ssize_t ci_ll_write(struct dvb_ringbuffer *cibuf, struct file *file,
                           const char __user *buf, size_t count, loff_t *ppos)
{
        int free;
        int non_blocking = file->f_flags & O_NONBLOCK;
        u8 *page = (u8 *)__get_free_page(GFP_USER);
        int res;

        if (!page)
                return -ENOMEM;

        res = -EINVAL;
        if (count > 2048)
                goto out;

        res = -EFAULT;
        if (copy_from_user(page, buf, count))
                goto out;

        free = dvb_ringbuffer_free(cibuf);
        if (count + 2 > free) {
                res = -EWOULDBLOCK;
                if (non_blocking)
                        goto out;
                res = -ERESTARTSYS;
                if (wait_event_interruptible(cibuf->queue,
                                             (dvb_ringbuffer_free(cibuf) >= count + 2)))
                        goto out;
        }

        DVB_RINGBUFFER_WRITE_BYTE(cibuf, count >> 8);
        DVB_RINGBUFFER_WRITE_BYTE(cibuf, count & 0xff);

        res = dvb_ringbuffer_write(cibuf, page, count);
out:
        free_page((unsigned long)page);
        return res;
}

static ssize_t ci_ll_read(struct dvb_ringbuffer *cibuf, struct file *file,
                          char __user *buf, size_t count, loff_t *ppos)
{
        int avail;
        int non_blocking = file->f_flags & O_NONBLOCK;
        ssize_t len;

        if (!cibuf->data || !count)
                return 0;
        if (non_blocking && (dvb_ringbuffer_empty(cibuf)))
                return -EWOULDBLOCK;
        if (wait_event_interruptible(cibuf->queue,
                                     !dvb_ringbuffer_empty(cibuf)))
                return -ERESTARTSYS;
        avail = dvb_ringbuffer_avail(cibuf);
        if (avail < 4)
                return 0;
        len = DVB_RINGBUFFER_PEEK(cibuf, 0) << 8;
        len |= DVB_RINGBUFFER_PEEK(cibuf, 1);
        if (avail < len + 2 || count < len)
                return -EINVAL;
        DVB_RINGBUFFER_SKIP(cibuf, 2);

        return dvb_ringbuffer_read_user(cibuf, buf, len);
}

static int dvb_ca_open(struct inode *inode, struct file *file)
{
        struct dvb_device *dvbdev = file->private_data;
        struct av7110 *av7110 = dvbdev->priv;
        int err = dvb_generic_open(inode, file);

        dprintk(8, "av7110:%p\n", av7110);

        if (err < 0)
                return err;
        ci_ll_flush(&av7110->ci_rbuffer, &av7110->ci_wbuffer);
        return 0;
}

static __poll_t dvb_ca_poll(struct file *file, poll_table *wait)
{
        struct dvb_device *dvbdev = file->private_data;
        struct av7110 *av7110 = dvbdev->priv;
        struct dvb_ringbuffer *rbuf = &av7110->ci_rbuffer;
        struct dvb_ringbuffer *wbuf = &av7110->ci_wbuffer;
        __poll_t mask = 0;

        dprintk(8, "av7110:%p\n", av7110);

        poll_wait(file, &rbuf->queue, wait);
        poll_wait(file, &wbuf->queue, wait);

        if (!dvb_ringbuffer_empty(rbuf))
                mask |= (EPOLLIN | EPOLLRDNORM);

        if (dvb_ringbuffer_free(wbuf) > 1024)
                mask |= (EPOLLOUT | EPOLLWRNORM);

        return mask;
}

static int dvb_ca_ioctl(struct file *file, unsigned int cmd, void *parg)
{
        struct dvb_device *dvbdev = file->private_data;
        struct av7110 *av7110 = dvbdev->priv;
        unsigned long arg = (unsigned long)parg;
        int ret = 0;

        dprintk(8, "av7110:%p\n", av7110);

        if (mutex_lock_interruptible(&av7110->ioctl_mutex))
                return -ERESTARTSYS;

        switch (cmd) {
        case CA_RESET:
                ret = ci_ll_reset(&av7110->ci_wbuffer, file, arg,
                                  &av7110->ci_slot[0]);
                break;
        case CA_GET_CAP:
        {
                struct ca_caps cap;

                cap.slot_num = 2;
                cap.slot_type = (FW_CI_LL_SUPPORT(av7110->arm_app) ?
                                 CA_CI_LINK : CA_CI) | CA_DESCR;
                cap.descr_num = 16;
                cap.descr_type = CA_ECD;
                memcpy(parg, &cap, sizeof(cap));
                break;
        }

        case CA_GET_SLOT_INFO:
        {
                struct ca_slot_info *info = (struct ca_slot_info *)parg;
                unsigned int slot_num;

                if (info->num < 0 || info->num > 1) {
                        mutex_unlock(&av7110->ioctl_mutex);
                        return -EINVAL;
                }
                slot_num = array_index_nospec(info->num, MAX_CI_SLOTS);

                av7110->ci_slot[slot_num].num = info->num;
                av7110->ci_slot[slot_num].type = FW_CI_LL_SUPPORT(av7110->arm_app) ?
                                                 CA_CI_LINK : CA_CI;
                memcpy(info, &av7110->ci_slot[slot_num],
                       sizeof(struct ca_slot_info));
                break;
        }

        case CA_GET_MSG:
                break;

        case CA_SEND_MSG:
                break;

        case CA_GET_DESCR_INFO:
        {
                struct ca_descr_info info;

                info.num = 16;
                info.type = CA_ECD;
                memcpy(parg, &info, sizeof(info));
                break;
        }

        case CA_SET_DESCR:
        {
                struct ca_descr *descr = (struct ca_descr *)parg;

                if (descr->index >= 16 || descr->parity > 1) {
                        mutex_unlock(&av7110->ioctl_mutex);
                        return -EINVAL;
                }
                av7110_fw_cmd(av7110, COMTYPE_PIDFILTER, SetDescr, 5,
                              (descr->index << 8) | descr->parity,
                              (descr->cw[0] << 8) | descr->cw[1],
                              (descr->cw[2] << 8) | descr->cw[3],
                              (descr->cw[4] << 8) | descr->cw[5],
                              (descr->cw[6] << 8) | descr->cw[7]);
                break;
        }

        default:
                ret = -EINVAL;
                break;
        }

        mutex_unlock(&av7110->ioctl_mutex);
        return ret;
}

static ssize_t dvb_ca_write(struct file *file, const char __user *buf,
                            size_t count, loff_t *ppos)
{
        struct dvb_device *dvbdev = file->private_data;
        struct av7110 *av7110 = dvbdev->priv;

        dprintk(8, "av7110:%p\n", av7110);
        return ci_ll_write(&av7110->ci_wbuffer, file, buf, count, ppos);
}

static ssize_t dvb_ca_read(struct file *file, char __user *buf,
                           size_t count, loff_t *ppos)
{
        struct dvb_device *dvbdev = file->private_data;
        struct av7110 *av7110 = dvbdev->priv;

        dprintk(8, "av7110:%p\n", av7110);
        return ci_ll_read(&av7110->ci_rbuffer, file, buf, count, ppos);
}

static const struct file_operations dvb_ca_fops = {
        .owner          = THIS_MODULE,
        .read           = dvb_ca_read,
        .write          = dvb_ca_write,
        .unlocked_ioctl = dvb_generic_ioctl,
        .open           = dvb_ca_open,
        .release        = dvb_generic_release,
        .poll           = dvb_ca_poll,
        .llseek         = default_llseek,
};

static struct dvb_device dvbdev_ca = {
        .priv           = NULL,
        .users          = 1,
        .writers        = 1,
        .fops           = &dvb_ca_fops,
        .kernel_ioctl   = dvb_ca_ioctl,
};

int av7110_ca_register(struct av7110 *av7110)
{
        return dvb_register_device(&av7110->dvb_adapter, &av7110->ca_dev,
                                   &dvbdev_ca, av7110, DVB_DEVICE_CA, 0);
}

void av7110_ca_unregister(struct av7110 *av7110)
{
        dvb_unregister_device(av7110->ca_dev);
}

int av7110_ca_init(struct av7110 *av7110)
{
        return ci_ll_init(&av7110->ci_rbuffer, &av7110->ci_wbuffer, 8192);
}

void av7110_ca_exit(struct av7110 *av7110)
{
        ci_ll_release(&av7110->ci_rbuffer, &av7110->ci_wbuffer);
}