diff options
Diffstat (limited to 'drivers/media/radio/radio-typhoon.c')
| -rw-r--r-- | drivers/media/radio/radio-typhoon.c | 181 |
1 files changed, 181 insertions, 0 deletions
diff --git a/drivers/media/radio/radio-typhoon.c b/drivers/media/radio/radio-typhoon.c new file mode 100644 index 000000000..1aa856df7 --- /dev/null +++ b/drivers/media/radio/radio-typhoon.c @@ -0,0 +1,181 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Typhoon Radio Card driver for radio support + * (c) 1999 Dr. Henrik Seidel <Henrik.Seidel@gmx.de> + * + * 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 <mchehab@kernel.org> + */ + +#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 "0.1.2" + +MODULE_AUTHOR("Dr. Henrik Seidel"); +MODULE_DESCRIPTION("A driver for the Typhoon radio card (a.k.a. EcoRadio)."); +MODULE_LICENSE("GPL"); +MODULE_VERSION("0.1.99"); + +#ifndef CONFIG_RADIO_TYPHOON_PORT +#define CONFIG_RADIO_TYPHOON_PORT -1 +#endif + +#ifndef CONFIG_RADIO_TYPHOON_MUTEFREQ +#define CONFIG_RADIO_TYPHOON_MUTEFREQ 87000 +#endif + +#define TYPHOON_MAX 2 + +static int io[TYPHOON_MAX] = { [0] = CONFIG_RADIO_TYPHOON_PORT, + [1 ... (TYPHOON_MAX - 1)] = -1 }; +static int radio_nr[TYPHOON_MAX] = { [0 ... (TYPHOON_MAX - 1)] = -1 }; +static unsigned long mutefreq = CONFIG_RADIO_TYPHOON_MUTEFREQ; + +module_param_array(io, int, NULL, 0444); +MODULE_PARM_DESC(io, "I/O addresses of the Typhoon card (0x316 or 0x336)"); +module_param_array(radio_nr, int, NULL, 0444); +MODULE_PARM_DESC(radio_nr, "Radio device numbers"); +module_param(mutefreq, ulong, 0); +MODULE_PARM_DESC(mutefreq, "Frequency used when muting the card (in kHz)"); + +struct typhoon { + struct radio_isa_card isa; + int muted; +}; + +static struct radio_isa_card *typhoon_alloc(void) +{ + struct typhoon *ty = kzalloc(sizeof(*ty), GFP_KERNEL); + + return ty ? &ty->isa : NULL; +} + +static int typhoon_s_frequency(struct radio_isa_card *isa, u32 freq) +{ + unsigned long outval; + unsigned long x; + + /* + * The frequency transfer curve is not linear. The best fit I could + * get is + * + * outval = -155 + exp((f + 15.55) * 0.057)) + * + * where frequency f is in MHz. Since we don't have exp in the kernel, + * I approximate this function by a third order polynomial. + * + */ + + x = freq / 160; + outval = (x * x + 2500) / 5000; + outval = (outval * x + 5000) / 10000; + outval -= (10 * x * x + 10433) / 20866; + outval += 4 * x - 11505; + + outb_p((outval >> 8) & 0x01, isa->io + 4); + outb_p(outval >> 9, isa->io + 6); + outb_p(outval & 0xff, isa->io + 8); + return 0; +} + +static int typhoon_s_mute_volume(struct radio_isa_card *isa, bool mute, int vol) +{ + struct typhoon *ty = container_of(isa, struct typhoon, isa); + + if (mute) + vol = 0; + vol >>= 14; /* Map 16 bit to 2 bit */ + vol &= 3; + outb_p(vol / 2, isa->io); /* Set the volume, high bit. */ + outb_p(vol % 2, isa->io + 2); /* Set the volume, low bit. */ + + if (vol == 0 && !ty->muted) { + ty->muted = true; + return typhoon_s_frequency(isa, mutefreq << 4); + } + if (vol && ty->muted) { + ty->muted = false; + return typhoon_s_frequency(isa, isa->freq); + } + return 0; +} + +static const struct radio_isa_ops typhoon_ops = { + .alloc = typhoon_alloc, + .s_mute_volume = typhoon_s_mute_volume, + .s_frequency = typhoon_s_frequency, +}; + +static const int typhoon_ioports[] = { 0x316, 0x336 }; + +static struct radio_isa_driver typhoon_driver = { + .driver = { + .match = radio_isa_match, + .probe = radio_isa_probe, + .remove = radio_isa_remove, + .driver = { + .name = "radio-typhoon", + }, + }, + .io_params = io, + .radio_nr_params = radio_nr, + .io_ports = typhoon_ioports, + .num_of_io_ports = ARRAY_SIZE(typhoon_ioports), + .region_size = 8, + .card = "Typhoon Radio", + .ops = &typhoon_ops, + .has_stereo = true, + .max_volume = 3, +}; + +static int __init typhoon_init(void) +{ + if (mutefreq < 87000 || mutefreq > 108000) { + printk(KERN_ERR "%s: You must set a frequency (in kHz) used when muting the card,\n", + typhoon_driver.driver.driver.name); + printk(KERN_ERR "%s: e.g. with \"mutefreq=87500\" (87000 <= mutefreq <= 108000)\n", + typhoon_driver.driver.driver.name); + return -ENODEV; + } + return isa_register_driver(&typhoon_driver.driver, TYPHOON_MAX); +} + +static void __exit typhoon_exit(void) +{ + isa_unregister_driver(&typhoon_driver.driver); +} + + +module_init(typhoon_init); +module_exit(typhoon_exit); + |