drivers/media/radio/radio-typhoon.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /* Typhoon Radio Card driver for radio support
   3  * (c) 1999 Dr. Henrik Seidel <Henrik.Seidel@gmx.de>
   4  *
   5  * Notes on the hardware
   6  *
   7  * This card has two output sockets, one for speakers and one for line.
   8  * The speaker output has volume control, but only in four discrete
   9  * steps. The line output has neither volume control nor mute.
  10  *
  11  * The card has auto-stereo according to its manual, although it all
  12  * sounds mono to me (even with the Win/DOS drivers). Maybe it's my
  13  * antenna - I really don't know for sure.
  14  *
  15  * Frequency control is done digitally.
  16  *
  17  * Volume control is done digitally, but there are only four different
  18  * possible values. So you should better always turn the volume up and
  19  * use line control. I got the best results by connecting line output
  20  * to the sound card microphone input. For such a configuration the
  21  * volume control has no effect, since volume control only influences
  22  * the speaker output.
  23  *
  24  * There is no explicit mute/unmute. So I set the radio frequency to a
  25  * value where I do expect just noise and turn the speaker volume down.
  26  * The frequency change is necessary since the card never seems to be
  27  * completely silent.
  28  *
  29  * Converted to V4L2 API by Mauro Carvalho Chehab <mchehab@kernel.org>
  30  */
  31
  32 #include <linux/module.h>       /* Modules                        */
  33 #include <linux/init.h>         /* Initdata                       */
  34 #include <linux/ioport.h>       /* request_region                 */
  35 #include <linux/videodev2.h>    /* kernel radio structs           */
  36 #include <linux/io.h>           /* outb, outb_p                   */
  37 #include <linux/slab.h>
  38 #include <media/v4l2-device.h>
  39 #include <media/v4l2-ioctl.h>
  40 #include "radio-isa.h"
  41
  42 #define DRIVER_VERSION "0.1.2"
  43
  44 MODULE_AUTHOR("Dr. Henrik Seidel");
  45 MODULE_DESCRIPTION("A driver for the Typhoon radio card (a.k.a. EcoRadio).");
  46 MODULE_LICENSE("GPL");
  47 MODULE_VERSION("0.1.99");
  48
  49 #ifndef CONFIG_RADIO_TYPHOON_PORT
  50 #define CONFIG_RADIO_TYPHOON_PORT -1
  51 #endif
  52
  53 #ifndef CONFIG_RADIO_TYPHOON_MUTEFREQ
  54 #define CONFIG_RADIO_TYPHOON_MUTEFREQ 87000
  55 #endif
  56
  57 #define TYPHOON_MAX 2
  58
  59 static int io[TYPHOON_MAX] = { [0] = CONFIG_RADIO_TYPHOON_PORT,
  60                               [1 ... (TYPHOON_MAX - 1)] = -1 };
  61 static int radio_nr[TYPHOON_MAX]        = { [0 ... (TYPHOON_MAX - 1)] = -1 };
  62 static unsigned long mutefreq = CONFIG_RADIO_TYPHOON_MUTEFREQ;
  63
  64 module_param_array(io, int, NULL, 0444);
  65 MODULE_PARM_DESC(io, "I/O addresses of the Typhoon card (0x316 or 0x336)");
  66 module_param_array(radio_nr, int, NULL, 0444);
  67 MODULE_PARM_DESC(radio_nr, "Radio device numbers");
  68 module_param(mutefreq, ulong, 0);
  69 MODULE_PARM_DESC(mutefreq, "Frequency used when muting the card (in kHz)");
  70
  71 struct typhoon {
  72         struct radio_isa_card isa;
  73         int muted;
  74 };
  75
  76 static struct radio_isa_card *typhoon_alloc(void)
  77 {
  78         struct typhoon *ty = kzalloc(sizeof(*ty), GFP_KERNEL);
  79
  80         return ty ? &ty->isa : NULL;
  81 }
  82
  83 static int typhoon_s_frequency(struct radio_isa_card *isa, u32 freq)
  84 {
  85         unsigned long outval;
  86         unsigned long x;
  87
  88         /*
  89          * The frequency transfer curve is not linear. The best fit I could
  90          * get is
  91          *
  92          * outval = -155 + exp((f + 15.55) * 0.057))
  93          *
  94          * where frequency f is in MHz. Since we don't have exp in the kernel,
  95          * I approximate this function by a third order polynomial.
  96          *
  97          */
  98
  99         x = freq / 160;
 100         outval = (x * x + 2500) / 5000;
 101         outval = (outval * x + 5000) / 10000;
 102         outval -= (10 * x * x + 10433) / 20866;
 103         outval += 4 * x - 11505;
 104
 105         outb_p((outval >> 8) & 0x01, isa->io + 4);
 106         outb_p(outval >> 9, isa->io + 6);
 107         outb_p(outval & 0xff, isa->io + 8);
 108         return 0;
 109 }
 110
 111 static int typhoon_s_mute_volume(struct radio_isa_card *isa, bool mute, int vol)
 112 {
 113         struct typhoon *ty = container_of(isa, struct typhoon, isa);
 114
 115         if (mute)
 116                 vol = 0;
 117         vol >>= 14;                     /* Map 16 bit to 2 bit */
 118         vol &= 3;
 119         outb_p(vol / 2, isa->io);       /* Set the volume, high bit. */
 120         outb_p(vol % 2, isa->io + 2);   /* Set the volume, low bit. */
 121
 122         if (vol == 0 && !ty->muted) {
 123                 ty->muted = true;
 124                 return typhoon_s_frequency(isa, mutefreq << 4);
 125         }
 126         if (vol && ty->muted) {
 127                 ty->muted = false;
 128                 return typhoon_s_frequency(isa, isa->freq);
 129         }
 130         return 0;
 131 }
 132
 133 static const struct radio_isa_ops typhoon_ops = {
 134         .alloc = typhoon_alloc,
 135         .s_mute_volume = typhoon_s_mute_volume,
 136         .s_frequency = typhoon_s_frequency,
 137 };
 138
 139 static const int typhoon_ioports[] = { 0x316, 0x336 };
 140
 141 static struct radio_isa_driver typhoon_driver = {
 142         .driver = {
 143                 .match          = radio_isa_match,
 144                 .probe          = radio_isa_probe,
 145                 .remove         = radio_isa_remove,
 146                 .driver         = {
 147                         .name   = "radio-typhoon",
 148                 },
 149         },
 150         .io_params = io,
 151         .radio_nr_params = radio_nr,
 152         .io_ports = typhoon_ioports,
 153         .num_of_io_ports = ARRAY_SIZE(typhoon_ioports),
 154         .region_size = 8,
 155         .card = "Typhoon Radio",
 156         .ops = &typhoon_ops,
 157         .has_stereo = true,
 158         .max_volume = 3,
 159 };
 160
 161 static int __init typhoon_init(void)
 162 {
 163         if (mutefreq < 87000 || mutefreq > 108000) {
 164                 printk(KERN_ERR "%s: You must set a frequency (in kHz) used when muting the card,\n",
 165                                 typhoon_driver.driver.driver.name);
 166                 printk(KERN_ERR "%s: e.g. with \"mutefreq=87500\" (87000 <= mutefreq <= 108000)\n",
 167                                 typhoon_driver.driver.driver.name);
 168                 return -ENODEV;
 169         }
 170         return isa_register_driver(&typhoon_driver.driver, TYPHOON_MAX);
 171 }
 172
 173 static void __exit typhoon_exit(void)
 174 {
 175         isa_unregister_driver(&typhoon_driver.driver);
 176 }
 177
 178
 179 module_init(typhoon_init);
 180 module_exit(typhoon_exit);
 181