// SPDX-License-Identifier: GPL-2.0-only
/*
 * Miro PCM20 radio driver for Linux radio support
 * (c) 1998 Ruurd Reitsma <R.A.Reitsma@wbmt.tudelft.nl>
 * Thanks to Norberto Pellici for the ACI device interface specification
 * The API part is based on the radiotrack driver by M. Kirkwood
 * This driver relies on the aci mixer provided by the snd-miro
 * ALSA driver.
 * Look there for further info...
 *
 * From the original miro RDS sources:
 *
 *  (c) 2001 Robert Siemer <Robert.Siemer@gmx.de>
 *
 *  Many thanks to Fred Seidel <seidel@metabox.de>, the
 *  designer of the RDS decoder hardware. With his help
 *  I was able to code this driver.
 *  Thanks also to Norberto Pellicci, Dominic Mounteney
 *  <DMounteney@pinnaclesys.com> and www.teleauskunft.de
 *  for good hints on finding Fred. It was somewhat hard
 *  to locate him here in Germany... [:
 *
 * This code has been reintroduced and converted to use
 * the new V4L2 RDS API by:
 *
 * Hans Verkuil <hverkuil@kernel.org>
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/delay.h>
#include <linux/videodev2.h>
#include <linux/kthread.h>
#include <media/v4l2-device.h>
#include <media/v4l2-ioctl.h>
#include <media/v4l2-ctrls.h>
#include <media/v4l2-fh.h>
#include <media/v4l2-event.h>
#include <sound/aci.h>

#define RDS_DATASHIFT          2   /* Bit 2 */
#define RDS_DATAMASK        (1 << RDS_DATASHIFT)
#define RDS_BUSYMASK        0x10   /* Bit 4 */
#define RDS_CLOCKMASK       0x08   /* Bit 3 */
#define RDS_DATA(x)         (((x) >> RDS_DATASHIFT) & 1)

#define RDS_STATUS      0x01
#define RDS_STATIONNAME 0x02
#define RDS_TEXT        0x03
#define RDS_ALTFREQ     0x04
#define RDS_TIMEDATE    0x05
#define RDS_PI_CODE     0x06
#define RDS_PTYTATP     0x07
#define RDS_RESET       0x08
#define RDS_RXVALUE     0x09

static int radio_nr = -1;
module_param(radio_nr, int, 0);
MODULE_PARM_DESC(radio_nr, "Set radio device number (/dev/radioX).  Default: -1 (autodetect)");

struct pcm20 {
        struct v4l2_device v4l2_dev;
        struct video_device vdev;
        struct v4l2_ctrl_handler ctrl_handler;
        struct v4l2_ctrl *rds_pty;
        struct v4l2_ctrl *rds_ps_name;
        struct v4l2_ctrl *rds_radio_test;
        struct v4l2_ctrl *rds_ta;
        struct v4l2_ctrl *rds_tp;
        struct v4l2_ctrl *rds_ms;
        /* thread for periodic RDS status checking */
        struct task_struct *kthread;
        unsigned long freq;
        u32 audmode;
        struct snd_miro_aci *aci;
        struct mutex lock;
};

static struct pcm20 pcm20_card = {
        .freq = 87 * 16000,
        .audmode = V4L2_TUNER_MODE_STEREO,
};


static int rds_waitread(struct snd_miro_aci *aci)
{
        u8 byte;
        int i = 2000;

        do {
                byte = inb(aci->aci_port + ACI_REG_RDS);
                i--;
        } while ((byte & RDS_BUSYMASK) && i);

        /*
         * It's magic, but without this the data that you read later on
         * is unreliable and full of bit errors. With this 1 usec delay
         * everything is fine.
         */
        udelay(1);
        return i ? byte : -1;
}

static int rds_rawwrite(struct snd_miro_aci *aci, u8 byte)
{
        if (rds_waitread(aci) >= 0) {
                outb(byte, aci->aci_port + ACI_REG_RDS);
                return 0;
        }
        return -1;
}

static int rds_write(struct snd_miro_aci *aci, u8 byte)
{
        u8 sendbuffer[8];
        int i;

        for (i = 7; i >= 0; i--)
                sendbuffer[7 - i] = (byte & (1 << i)) ? RDS_DATAMASK : 0;
        sendbuffer[0] |= RDS_CLOCKMASK;

        for (i = 0; i < 8; i++)
                rds_rawwrite(aci, sendbuffer[i]);
        return 0;
}

static int rds_readcycle_nowait(struct snd_miro_aci *aci)
{
        outb(0, aci->aci_port + ACI_REG_RDS);
        return rds_waitread(aci);
}

static int rds_readcycle(struct snd_miro_aci *aci)
{
        if (rds_rawwrite(aci, 0) < 0)
                return -1;
        return rds_waitread(aci);
}

static int rds_ack(struct snd_miro_aci *aci)
{
        int i = rds_readcycle(aci);

        if (i < 0)
                return -1;
        if (i & RDS_DATAMASK)
                return 0;  /* ACK  */
        return 1;  /* NACK */
}

static int rds_cmd(struct snd_miro_aci *aci, u8 cmd, u8 databuffer[], u8 datasize)
{
        int i, j;

        rds_write(aci, cmd);

        /* RDS_RESET doesn't need further processing */
        if (cmd == RDS_RESET)
                return 0;
        if (rds_ack(aci))
                return -EIO;
        if (datasize == 0)
                return 0;

        /* to be able to use rds_readcycle_nowait()
           I have to waitread() here */
        if (rds_waitread(aci) < 0)
                return -1;

        memset(databuffer, 0, datasize);

        for (i = 0; i < 8 * datasize; i++) {
                j = rds_readcycle_nowait(aci);
                if (j < 0)
                        return -EIO;
                databuffer[i / 8] |= RDS_DATA(j) << (7 - (i % 8));
        }
        return 0;
}

static int pcm20_setfreq(struct pcm20 *dev, unsigned long freq)
{
        unsigned char freql;
        unsigned char freqh;
        struct snd_miro_aci *aci = dev->aci;

        freq /= 160;
        if (!(aci->aci_version == 0x07 || aci->aci_version >= 0xb0))
                freq /= 10;  /* I don't know exactly which version
                              * needs this hack */
        freql = freq & 0xff;
        freqh = freq >> 8;

        rds_cmd(aci, RDS_RESET, NULL, 0);
        return snd_aci_cmd(aci, ACI_WRITE_TUNE, freql, freqh);
}

static int vidioc_querycap(struct file *file, void *priv,
                                struct v4l2_capability *v)
{
        strscpy(v->driver, "Miro PCM20", sizeof(v->driver));
        strscpy(v->card, "Miro PCM20", sizeof(v->card));
        strscpy(v->bus_info, "ISA:radio-miropcm20", sizeof(v->bus_info));
        return 0;
}

static bool sanitize(char *p, int size)
{
        int i;
        bool ret = true;

        for (i = 0; i < size; i++) {
                if (p[i] < 32) {
                        p[i] = ' ';
                        ret = false;
                }
        }
        return ret;
}

static int vidioc_g_tuner(struct file *file, void *priv,
                                struct v4l2_tuner *v)
{
        struct pcm20 *dev = video_drvdata(file);
        int res;
        u8 buf;

        if (v->index)
                return -EINVAL;
        strscpy(v->name, "FM", sizeof(v->name));
        v->type = V4L2_TUNER_RADIO;
        v->rangelow = 87*16000;
        v->rangehigh = 108*16000;
        res = snd_aci_cmd(dev->aci, ACI_READ_TUNERSTATION, -1, -1);
        v->signal = (res & 0x80) ? 0 : 0xffff;
        /* Note: stereo detection does not work if the audio is muted,
           it will default to mono in that case. */
        res = snd_aci_cmd(dev->aci, ACI_READ_TUNERSTEREO, -1, -1);
        v->rxsubchans = (res & 0x40) ? V4L2_TUNER_SUB_MONO :
                                        V4L2_TUNER_SUB_STEREO;
        v->capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO |
                        V4L2_TUNER_CAP_RDS | V4L2_TUNER_CAP_RDS_CONTROLS;
        v->audmode = dev->audmode;
        res = rds_cmd(dev->aci, RDS_RXVALUE, &buf, 1);
        if (res >= 0 && buf)
                v->rxsubchans |= V4L2_TUNER_SUB_RDS;
        return 0;
}

static int vidioc_s_tuner(struct file *file, void *priv,
                                const struct v4l2_tuner *v)
{
        struct pcm20 *dev = video_drvdata(file);

        if (v->index)
                return -EINVAL;
        if (v->audmode > V4L2_TUNER_MODE_STEREO)
                dev->audmode = V4L2_TUNER_MODE_STEREO;
        else
                dev->audmode = v->audmode;
        snd_aci_cmd(dev->aci, ACI_SET_TUNERMONO,
                        dev->audmode == V4L2_TUNER_MODE_MONO, -1);
        return 0;
}

static int vidioc_g_frequency(struct file *file, void *priv,
                                struct v4l2_frequency *f)
{
        struct pcm20 *dev = video_drvdata(file);

        if (f->tuner != 0)
                return -EINVAL;

        f->type = V4L2_TUNER_RADIO;
        f->frequency = dev->freq;
        return 0;
}


static int vidioc_s_frequency(struct file *file, void *priv,
                                const struct v4l2_frequency *f)
{
        struct pcm20 *dev = video_drvdata(file);

        if (f->tuner != 0 || f->type != V4L2_TUNER_RADIO)
                return -EINVAL;

        dev->freq = clamp_t(u32, f->frequency, 87 * 16000U, 108 * 16000U);
        pcm20_setfreq(dev, dev->freq);
        return 0;
}

static int pcm20_s_ctrl(struct v4l2_ctrl *ctrl)
{
        struct pcm20 *dev = container_of(ctrl->handler, struct pcm20, ctrl_handler);

        switch (ctrl->id) {
        case V4L2_CID_AUDIO_MUTE:
                snd_aci_cmd(dev->aci, ACI_SET_TUNERMUTE, ctrl->val, -1);
                return 0;
        }
        return -EINVAL;
}

static int pcm20_thread(void *data)
{
        struct pcm20 *dev = data;
        const unsigned no_rds_start_counter = 5;
        const unsigned sleep_msecs = 2000;
        unsigned no_rds_counter = no_rds_start_counter;

        for (;;) {
                char text_buffer[66];
                u8 buf;
                int res;

                msleep_interruptible(sleep_msecs);

                if (kthread_should_stop())
                        break;

                res = rds_cmd(dev->aci, RDS_RXVALUE, &buf, 1);
                if (res)
                        continue;
                if (buf == 0) {
                        if (no_rds_counter == 0)
                                continue;
                        no_rds_counter--;
                        if (no_rds_counter)
                                continue;

                        /*
                         * No RDS seen for no_rds_start_counter * sleep_msecs
                         * milliseconds, clear all RDS controls to their
                         * default values.
                         */
                        v4l2_ctrl_s_ctrl_string(dev->rds_ps_name, "");
                        v4l2_ctrl_s_ctrl(dev->rds_ms, 1);
                        v4l2_ctrl_s_ctrl(dev->rds_ta, 0);
                        v4l2_ctrl_s_ctrl(dev->rds_tp, 0);
                        v4l2_ctrl_s_ctrl(dev->rds_pty, 0);
                        v4l2_ctrl_s_ctrl_string(dev->rds_radio_test, "");
                        continue;
                }
                no_rds_counter = no_rds_start_counter;

                res = rds_cmd(dev->aci, RDS_STATUS, &buf, 1);
                if (res)
                        continue;
                if ((buf >> 3) & 1) {
                        res = rds_cmd(dev->aci, RDS_STATIONNAME, text_buffer, 8);
                        text_buffer[8] = 0;
                        if (!res && sanitize(text_buffer, 8))
                                v4l2_ctrl_s_ctrl_string(dev->rds_ps_name, text_buffer);
                }
                if ((buf >> 6) & 1) {
                        u8 pty;

                        res = rds_cmd(dev->aci, RDS_PTYTATP, &pty, 1);
                        if (!res) {
                                v4l2_ctrl_s_ctrl(dev->rds_ms, !!(pty & 0x01));
                                v4l2_ctrl_s_ctrl(dev->rds_ta, !!(pty & 0x02));
                                v4l2_ctrl_s_ctrl(dev->rds_tp, !!(pty & 0x80));
                                v4l2_ctrl_s_ctrl(dev->rds_pty, (pty >> 2) & 0x1f);
                        }
                }
                if ((buf >> 4) & 1) {
                        res = rds_cmd(dev->aci, RDS_TEXT, text_buffer, 65);
                        text_buffer[65] = 0;
                        if (!res && sanitize(text_buffer + 1, 64))
                                v4l2_ctrl_s_ctrl_string(dev->rds_radio_test, text_buffer + 1);
                }
        }
        return 0;
}

static int pcm20_open(struct file *file)
{
        struct pcm20 *dev = video_drvdata(file);
        int res = v4l2_fh_open(file);

        if (!res && v4l2_fh_is_singular_file(file) &&
            IS_ERR_OR_NULL(dev->kthread)) {
                dev->kthread = kthread_run(pcm20_thread, dev, "%s",
                                           dev->v4l2_dev.name);
                if (IS_ERR(dev->kthread)) {
                        v4l2_err(&dev->v4l2_dev, "kernel_thread() failed\n");
                        v4l2_fh_release(file);
                        return PTR_ERR(dev->kthread);
                }
        }
        return res;
}

static int pcm20_release(struct file *file)
{
        struct pcm20 *dev = video_drvdata(file);

        if (v4l2_fh_is_singular_file(file) && !IS_ERR_OR_NULL(dev->kthread)) {
                kthread_stop(dev->kthread);
                dev->kthread = NULL;
        }
        return v4l2_fh_release(file);
}

static const struct v4l2_file_operations pcm20_fops = {
        .owner          = THIS_MODULE,
        .open           = pcm20_open,
        .poll           = v4l2_ctrl_poll,
        .release        = pcm20_release,
        .unlocked_ioctl = video_ioctl2,
};

static const struct v4l2_ioctl_ops pcm20_ioctl_ops = {
        .vidioc_querycap    = vidioc_querycap,
        .vidioc_g_tuner     = vidioc_g_tuner,
        .vidioc_s_tuner     = vidioc_s_tuner,
        .vidioc_g_frequency = vidioc_g_frequency,
        .vidioc_s_frequency = vidioc_s_frequency,
        .vidioc_log_status  = v4l2_ctrl_log_status,
        .vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
        .vidioc_unsubscribe_event = v4l2_event_unsubscribe,
};

static const struct v4l2_ctrl_ops pcm20_ctrl_ops = {
        .s_ctrl = pcm20_s_ctrl,
};

static int __init pcm20_init(void)
{
        struct pcm20 *dev = &pcm20_card;
        struct v4l2_device *v4l2_dev = &dev->v4l2_dev;
        struct v4l2_ctrl_handler *hdl;
        int res;

        dev->aci = snd_aci_get_aci();
        if (dev->aci == NULL) {
                v4l2_err(v4l2_dev,
                         "you must load the snd-miro driver first!\n");
                return -ENODEV;
        }
        strscpy(v4l2_dev->name, "radio-miropcm20", sizeof(v4l2_dev->name));
        mutex_init(&dev->lock);

        res = v4l2_device_register(NULL, v4l2_dev);
        if (res < 0) {
                v4l2_err(v4l2_dev, "could not register v4l2_device\n");
                return -EINVAL;
        }

        hdl = &dev->ctrl_handler;
        v4l2_ctrl_handler_init(hdl, 7);
        v4l2_ctrl_new_std(hdl, &pcm20_ctrl_ops,
                        V4L2_CID_AUDIO_MUTE, 0, 1, 1, 1);
        dev->rds_pty = v4l2_ctrl_new_std(hdl, NULL,
                        V4L2_CID_RDS_RX_PTY, 0, 0x1f, 1, 0);
        dev->rds_ps_name = v4l2_ctrl_new_std(hdl, NULL,
                        V4L2_CID_RDS_RX_PS_NAME, 0, 8, 8, 0);
        dev->rds_radio_test = v4l2_ctrl_new_std(hdl, NULL,
                        V4L2_CID_RDS_RX_RADIO_TEXT, 0, 64, 64, 0);
        dev->rds_ta = v4l2_ctrl_new_std(hdl, NULL,
                        V4L2_CID_RDS_RX_TRAFFIC_ANNOUNCEMENT, 0, 1, 1, 0);
        dev->rds_tp = v4l2_ctrl_new_std(hdl, NULL,
                        V4L2_CID_RDS_RX_TRAFFIC_PROGRAM, 0, 1, 1, 0);
        dev->rds_ms = v4l2_ctrl_new_std(hdl, NULL,
                        V4L2_CID_RDS_RX_MUSIC_SPEECH, 0, 1, 1, 1);
        v4l2_dev->ctrl_handler = hdl;
        if (hdl->error) {
                res = hdl->error;
                v4l2_err(v4l2_dev, "Could not register control\n");
                goto err_hdl;
        }
        strscpy(dev->vdev.name, v4l2_dev->name, sizeof(dev->vdev.name));
        dev->vdev.v4l2_dev = v4l2_dev;
        dev->vdev.fops = &pcm20_fops;
        dev->vdev.ioctl_ops = &pcm20_ioctl_ops;
        dev->vdev.release = video_device_release_empty;
        dev->vdev.lock = &dev->lock;
        dev->vdev.device_caps = V4L2_CAP_TUNER | V4L2_CAP_RADIO |
                                V4L2_CAP_RDS_CAPTURE;
        video_set_drvdata(&dev->vdev, dev);
        snd_aci_cmd(dev->aci, ACI_SET_TUNERMONO,
                        dev->audmode == V4L2_TUNER_MODE_MONO, -1);
        pcm20_setfreq(dev, dev->freq);

        if (video_register_device(&dev->vdev, VFL_TYPE_RADIO, radio_nr) < 0)
                goto err_hdl;

        v4l2_info(v4l2_dev, "Mirosound PCM20 Radio tuner\n");
        return 0;
err_hdl:
        v4l2_ctrl_handler_free(hdl);
        v4l2_device_unregister(v4l2_dev);
        return -EINVAL;
}

MODULE_AUTHOR("Ruurd Reitsma, Krzysztof Helt");
MODULE_DESCRIPTION("A driver for the Miro PCM20 radio card.");
MODULE_LICENSE("GPL");

static void __exit pcm20_cleanup(void)
{
        struct pcm20 *dev = &pcm20_card;

        video_unregister_device(&dev->vdev);
        snd_aci_cmd(dev->aci, ACI_SET_TUNERMUTE, 1, -1);
        v4l2_ctrl_handler_free(&dev->ctrl_handler);
        v4l2_device_unregister(&dev->v4l2_dev);
}

module_init(pcm20_init);
module_exit(pcm20_cleanup);