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 
182