drivers/media/radio/radio-typhoon.c

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