root/drivers/media/radio/radio-isa.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Framework for ISA radio drivers.
 * This takes care of all the V4L2 scaffolding, allowing the ISA drivers
 * to concentrate on the actual hardware operation.
 *
 * Copyright (C) 2012 Hans Verkuil <hverkuil@kernel.org>
 */

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

#include "radio-isa.h"

MODULE_AUTHOR("Hans Verkuil");
MODULE_DESCRIPTION("A framework for ISA radio drivers.");
MODULE_LICENSE("GPL");

#define FREQ_LOW  (87U * 16000U)
#define FREQ_HIGH (108U * 16000U)

static int radio_isa_querycap(struct file *file, void  *priv,
                                        struct v4l2_capability *v)
{
        struct radio_isa_card *isa = video_drvdata(file);

        strscpy(v->driver, isa->drv->driver.driver.name, sizeof(v->driver));
        strscpy(v->card, isa->drv->card, sizeof(v->card));
        snprintf(v->bus_info, sizeof(v->bus_info), "ISA:%s", dev_name(isa->v4l2_dev.dev));
        return 0;
}

static int radio_isa_g_tuner(struct file *file, void *priv,
                                struct v4l2_tuner *v)
{
        struct radio_isa_card *isa = video_drvdata(file);
        const struct radio_isa_ops *ops = isa->drv->ops;

        if (v->index > 0)
                return -EINVAL;

        strscpy(v->name, "FM", sizeof(v->name));
        v->type = V4L2_TUNER_RADIO;
        v->rangelow = FREQ_LOW;
        v->rangehigh = FREQ_HIGH;
        v->capability = V4L2_TUNER_CAP_LOW;
        if (isa->drv->has_stereo)
                v->capability |= V4L2_TUNER_CAP_STEREO;

        if (ops->g_rxsubchans)
                v->rxsubchans = ops->g_rxsubchans(isa);
        else
                v->rxsubchans = V4L2_TUNER_SUB_MONO | V4L2_TUNER_SUB_STEREO;
        v->audmode = isa->stereo ? V4L2_TUNER_MODE_STEREO : V4L2_TUNER_MODE_MONO;
        if (ops->g_signal)
                v->signal = ops->g_signal(isa);
        else
                v->signal = (v->rxsubchans & V4L2_TUNER_SUB_STEREO) ?
                                                                0xffff : 0;
        return 0;
}

static int radio_isa_s_tuner(struct file *file, void *priv,
                                const struct v4l2_tuner *v)
{
        struct radio_isa_card *isa = video_drvdata(file);
        const struct radio_isa_ops *ops = isa->drv->ops;

        if (v->index)
                return -EINVAL;
        if (ops->s_stereo) {
                isa->stereo = (v->audmode == V4L2_TUNER_MODE_STEREO);
                return ops->s_stereo(isa, isa->stereo);
        }
        return 0;
}

static int radio_isa_s_frequency(struct file *file, void *priv,
                                const struct v4l2_frequency *f)
{
        struct radio_isa_card *isa = video_drvdata(file);
        u32 freq = f->frequency;
        int res;

        if (f->tuner != 0 || f->type != V4L2_TUNER_RADIO)
                return -EINVAL;
        freq = clamp(freq, FREQ_LOW, FREQ_HIGH);
        res = isa->drv->ops->s_frequency(isa, freq);
        if (res == 0)
                isa->freq = freq;
        return res;
}

static int radio_isa_g_frequency(struct file *file, void *priv,
                                struct v4l2_frequency *f)
{
        struct radio_isa_card *isa = video_drvdata(file);

        if (f->tuner != 0)
                return -EINVAL;
        f->type = V4L2_TUNER_RADIO;
        f->frequency = isa->freq;
        return 0;
}

static int radio_isa_s_ctrl(struct v4l2_ctrl *ctrl)
{
        struct radio_isa_card *isa =
                container_of(ctrl->handler, struct radio_isa_card, hdl);

        switch (ctrl->id) {
        case V4L2_CID_AUDIO_MUTE:
                return isa->drv->ops->s_mute_volume(isa, ctrl->val,
                                isa->volume ? isa->volume->val : 0);
        }
        return -EINVAL;
}

static int radio_isa_log_status(struct file *file, void *priv)
{
        struct radio_isa_card *isa = video_drvdata(file);

        v4l2_info(&isa->v4l2_dev, "I/O Port = 0x%03x\n", isa->io);
        v4l2_ctrl_handler_log_status(&isa->hdl, isa->v4l2_dev.name);
        return 0;
}

static const struct v4l2_ctrl_ops radio_isa_ctrl_ops = {
        .s_ctrl = radio_isa_s_ctrl,
};

static const struct v4l2_file_operations radio_isa_fops = {
        .owner          = THIS_MODULE,
        .open           = v4l2_fh_open,
        .release        = v4l2_fh_release,
        .poll           = v4l2_ctrl_poll,
        .unlocked_ioctl = video_ioctl2,
};

static const struct v4l2_ioctl_ops radio_isa_ioctl_ops = {
        .vidioc_querycap    = radio_isa_querycap,
        .vidioc_g_tuner     = radio_isa_g_tuner,
        .vidioc_s_tuner     = radio_isa_s_tuner,
        .vidioc_g_frequency = radio_isa_g_frequency,
        .vidioc_s_frequency = radio_isa_s_frequency,
        .vidioc_log_status  = radio_isa_log_status,
        .vidioc_subscribe_event   = v4l2_ctrl_subscribe_event,
        .vidioc_unsubscribe_event = v4l2_event_unsubscribe,
};

int radio_isa_match(struct device *pdev, unsigned int dev)
{
        struct radio_isa_driver *drv = pdev->platform_data;

        return drv->probe || drv->io_params[dev] >= 0;
}
EXPORT_SYMBOL_GPL(radio_isa_match);

static bool radio_isa_valid_io(const struct radio_isa_driver *drv, int io)
{
        int i;

        for (i = 0; i < drv->num_of_io_ports; i++)
                if (drv->io_ports[i] == io)
                        return true;
        return false;
}

static struct radio_isa_card *radio_isa_alloc(struct radio_isa_driver *drv,
                                struct device *pdev)
{
        struct v4l2_device *v4l2_dev;
        struct radio_isa_card *isa = drv->ops->alloc();
        if (!isa)
                return NULL;

        dev_set_drvdata(pdev, isa);
        isa->drv = drv;
        v4l2_dev = &isa->v4l2_dev;
        strscpy(v4l2_dev->name, dev_name(pdev), sizeof(v4l2_dev->name));

        return isa;
}

static int radio_isa_common_probe(struct radio_isa_card *isa,
                                  struct device *pdev,
                                  int radio_nr, unsigned region_size)
{
        const struct radio_isa_driver *drv = isa->drv;
        const struct radio_isa_ops *ops = drv->ops;
        struct v4l2_device *v4l2_dev = &isa->v4l2_dev;
        int res;

        if (!request_region(isa->io, region_size, v4l2_dev->name)) {
                v4l2_err(v4l2_dev, "port 0x%x already in use\n", isa->io);
                kfree(isa);
                return -EBUSY;
        }

        res = v4l2_device_register(pdev, v4l2_dev);
        if (res < 0) {
                v4l2_err(v4l2_dev, "Could not register v4l2_device\n");
                goto err_dev_reg;
        }

        v4l2_ctrl_handler_init(&isa->hdl, 1);
        isa->mute = v4l2_ctrl_new_std(&isa->hdl, &radio_isa_ctrl_ops,
                                V4L2_CID_AUDIO_MUTE, 0, 1, 1, 1);
        if (drv->max_volume)
                isa->volume = v4l2_ctrl_new_std(&isa->hdl, &radio_isa_ctrl_ops,
                        V4L2_CID_AUDIO_VOLUME, 0, drv->max_volume, 1,
                        drv->max_volume);
        v4l2_dev->ctrl_handler = &isa->hdl;
        if (isa->hdl.error) {
                res = isa->hdl.error;
                v4l2_err(v4l2_dev, "Could not register controls\n");
                goto err_hdl;
        }
        if (drv->max_volume)
                v4l2_ctrl_cluster(2, &isa->mute);
        v4l2_dev->ctrl_handler = &isa->hdl;

        mutex_init(&isa->lock);
        isa->vdev.lock = &isa->lock;
        strscpy(isa->vdev.name, v4l2_dev->name, sizeof(isa->vdev.name));
        isa->vdev.v4l2_dev = v4l2_dev;
        isa->vdev.fops = &radio_isa_fops;
        isa->vdev.ioctl_ops = &radio_isa_ioctl_ops;
        isa->vdev.release = video_device_release_empty;
        isa->vdev.device_caps = V4L2_CAP_TUNER | V4L2_CAP_RADIO;
        video_set_drvdata(&isa->vdev, isa);
        isa->freq = FREQ_LOW;
        isa->stereo = drv->has_stereo;

        if (ops->init)
                res = ops->init(isa);
        if (!res)
                res = v4l2_ctrl_handler_setup(&isa->hdl);
        if (!res)
                res = ops->s_frequency(isa, isa->freq);
        if (!res && ops->s_stereo)
                res = ops->s_stereo(isa, isa->stereo);
        if (res < 0) {
                v4l2_err(v4l2_dev, "Could not setup card\n");
                goto err_hdl;
        }
        res = video_register_device(&isa->vdev, VFL_TYPE_RADIO, radio_nr);

        if (res < 0) {
                v4l2_err(v4l2_dev, "Could not register device node\n");
                goto err_hdl;
        }

        v4l2_info(v4l2_dev, "Initialized radio card %s on port 0x%03x\n",
                        drv->card, isa->io);
        return 0;

err_hdl:
        v4l2_ctrl_handler_free(&isa->hdl);
err_dev_reg:
        release_region(isa->io, region_size);
        kfree(isa);
        return res;
}

static void radio_isa_common_remove(struct radio_isa_card *isa,
                                    unsigned region_size)
{
        const struct radio_isa_ops *ops = isa->drv->ops;

        ops->s_mute_volume(isa, true, isa->volume ? isa->volume->cur.val : 0);
        video_unregister_device(&isa->vdev);
        v4l2_ctrl_handler_free(&isa->hdl);
        v4l2_device_unregister(&isa->v4l2_dev);
        release_region(isa->io, region_size);
        v4l2_info(&isa->v4l2_dev, "Removed radio card %s\n", isa->drv->card);
        kfree(isa);
}

int radio_isa_probe(struct device *pdev, unsigned int dev)
{
        struct radio_isa_driver *drv = pdev->platform_data;
        const struct radio_isa_ops *ops = drv->ops;
        struct v4l2_device *v4l2_dev;
        struct radio_isa_card *isa;

        isa = radio_isa_alloc(drv, pdev);
        if (!isa)
                return -ENOMEM;
        isa->io = drv->io_params[dev];
        v4l2_dev = &isa->v4l2_dev;

        if (drv->probe && ops->probe) {
                int i;

                for (i = 0; i < drv->num_of_io_ports; ++i) {
                        int io = drv->io_ports[i];

                        if (request_region(io, drv->region_size, v4l2_dev->name)) {
                                bool found = ops->probe(isa, io);

                                release_region(io, drv->region_size);
                                if (found) {
                                        isa->io = io;
                                        break;
                                }
                        }
                }
        }

        if (!radio_isa_valid_io(drv, isa->io)) {
                int i;

                if (isa->io < 0)
                        return -ENODEV;
                v4l2_err(v4l2_dev, "you must set an I/O address with io=0x%03x",
                                drv->io_ports[0]);
                for (i = 1; i < drv->num_of_io_ports; i++)
                        printk(KERN_CONT "/0x%03x", drv->io_ports[i]);
                printk(KERN_CONT ".\n");
                kfree(isa);
                return -EINVAL;
        }

        return radio_isa_common_probe(isa, pdev, drv->radio_nr_params[dev],
                                        drv->region_size);
}
EXPORT_SYMBOL_GPL(radio_isa_probe);

void radio_isa_remove(struct device *pdev, unsigned int dev)
{
        struct radio_isa_card *isa = dev_get_drvdata(pdev);

        radio_isa_common_remove(isa, isa->drv->region_size);
}
EXPORT_SYMBOL_GPL(radio_isa_remove);

#ifdef CONFIG_PNP
int radio_isa_pnp_probe(struct pnp_dev *dev, const struct pnp_device_id *dev_id)
{
        struct pnp_driver *pnp_drv = to_pnp_driver(dev->dev.driver);
        struct radio_isa_driver *drv = container_of(pnp_drv,
                                        struct radio_isa_driver, pnp_driver);
        struct radio_isa_card *isa;

        if (!pnp_port_valid(dev, 0))
                return -ENODEV;

        isa = radio_isa_alloc(drv, &dev->dev);
        if (!isa)
                return -ENOMEM;

        isa->io = pnp_port_start(dev, 0);

        return radio_isa_common_probe(isa, &dev->dev, drv->radio_nr_params[0],
                                        pnp_port_len(dev, 0));
}
EXPORT_SYMBOL_GPL(radio_isa_pnp_probe);

void radio_isa_pnp_remove(struct pnp_dev *dev)
{
        struct radio_isa_card *isa = dev_get_drvdata(&dev->dev);

        radio_isa_common_remove(isa, pnp_port_len(dev, 0));
}
EXPORT_SYMBOL_GPL(radio_isa_pnp_remove);
#endif