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
43MODULE_AUTHOR("Dr. Henrik Seidel");
44MODULE_DESCRIPTION("A driver for the Typhoon radio card (a.k.a. EcoRadio).");
45MODULE_LICENSE("GPL");
46MODULE_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
58static int io[TYPHOON_MAX] = { [0] = CONFIG_RADIO_TYPHOON_PORT,
59			      [1 ... (TYPHOON_MAX - 1)] = -1 };
60static int radio_nr[TYPHOON_MAX]	= { [0 ... (TYPHOON_MAX - 1)] = -1 };
61static unsigned long mutefreq = CONFIG_RADIO_TYPHOON_MUTEFREQ;
62
63module_param_array(io, int, NULL, 0444);
64MODULE_PARM_DESC(io, "I/O addresses of the Typhoon card (0x316 or 0x336)");
65module_param_array(radio_nr, int, NULL, 0444);
66MODULE_PARM_DESC(radio_nr, "Radio device numbers");
67module_param(mutefreq, ulong, 0);
68MODULE_PARM_DESC(mutefreq, "Frequency used when muting the card (in kHz)");
69
70struct typhoon {
71	struct radio_isa_card isa;
72	int muted;
73};
74
75static 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
82static 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
110static 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
132static 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
138static const int typhoon_ioports[] = { 0x316, 0x336 };
139
140static 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
160static 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
172static void __exit typhoon_exit(void)
173{
174	isa_unregister_driver(&typhoon_driver.driver);
175}
176
177
178module_init(typhoon_init);
179module_exit(typhoon_exit);
180
181