linux/drivers/media/radio/radio-typhoon.c

// SPDX-License-Identifier: GPL-2.0-only
/* Typhoon Radio Card driver for radio support
 * (c) 1999 Dr. Henrik Seidel <[email protected]>
 *
 * Notes on the hardware
 *
 * This card has two output sockets, one for speakers and one for line.
 * The speaker output has volume control, but only in four discrete
 * steps. The line output has neither volume control nor mute.
 *
 * The card has auto-stereo according to its manual, although it all
 * sounds mono to me (even with the Win/DOS drivers). Maybe it's my
 * antenna - I really don't know for sure.
 *
 * Frequency control is done digitally.
 *
 * Volume control is done digitally, but there are only four different
 * possible values. So you should better always turn the volume up and
 * use line control. I got the best results by connecting line output
 * to the sound card microphone input. For such a configuration the
 * volume control has no effect, since volume control only influences
 * the speaker output.
 *
 * There is no explicit mute/unmute. So I set the radio frequency to a
 * value where I do expect just noise and turn the speaker volume down.
 * The frequency change is necessary since the card never seems to be
 * completely silent.
 *
 * Converted to V4L2 API by Mauro Carvalho Chehab <[email protected]>
 */

#include <linux/module.h>	/* Modules                        */
#include <linux/init.h>		/* Initdata                       */
#include <linux/ioport.h>	/* request_region		  */
#include <linux/videodev2.h>	/* kernel radio structs           */
#include <linux/io.h>		/* outb, outb_p                   */
#include <linux/slab.h>
#include <media/v4l2-device.h>
#include <media/v4l2-ioctl.h>
#include "radio-isa.h"

#define DRIVER_VERSION …

MODULE_AUTHOR(…) …;
MODULE_DESCRIPTION(…) …;
MODULE_LICENSE(…) …;
MODULE_VERSION(…) …;

#ifndef CONFIG_RADIO_TYPHOON_PORT
#define CONFIG_RADIO_TYPHOON_PORT …
#endif

#ifndef CONFIG_RADIO_TYPHOON_MUTEFREQ
#define CONFIG_RADIO_TYPHOON_MUTEFREQ …
#endif

#define TYPHOON_MAX …

static int io[TYPHOON_MAX] = …;
static int radio_nr[TYPHOON_MAX]	= …;
static unsigned long mutefreq = …;

module_param_array(…);
MODULE_PARM_DESC(…) …;
module_param_array(…);
MODULE_PARM_DESC(…) …;
module_param(mutefreq, ulong, 0);
MODULE_PARM_DESC(…) …;

struct typhoon { … };

static struct radio_isa_card *typhoon_alloc(void)
{ … }

static int typhoon_s_frequency(struct radio_isa_card *isa, u32 freq)
{ … }

static int typhoon_s_mute_volume(struct radio_isa_card *isa, bool mute, int vol)
{ … }

static const struct radio_isa_ops typhoon_ops = …;

static const int typhoon_ioports[] = …;

static struct radio_isa_driver typhoon_driver = …;

static int __init typhoon_init(void)
{ … }

static void __exit typhoon_exit(void)
{ … }


module_init(…) …;
module_exit(typhoon_exit);