1 /*
2  * GemTek radio card driver
3  *
4  * Copyright 1998 Jonas Munsin <jmunsin@iki.fi>
5  *
6  * GemTek hasn't released any specs on the card, so the protocol had to
7  * be reverse engineered with dosemu.
8  *
9  * Besides the protocol changes, this is mostly a copy of:
10  *
11  *    RadioTrack II driver for Linux radio support (C) 1998 Ben Pfaff
12  *
13  *    Based on RadioTrack I/RadioReveal (C) 1997 M. Kirkwood
14  *    Converted to new API by Alan Cox <alan@lxorguk.ukuu.org.uk>
15  *    Various bugfixes and enhancements by Russell Kroll <rkroll@exploits.org>
16  *
17  * Converted to the radio-isa framework by Hans Verkuil <hans.verkuil@cisco.com>
18  * Converted to V4L2 API by Mauro Carvalho Chehab <mchehab@infradead.org>
19  *
20  * Note: this card seems to swap the left and right audio channels!
21  *
22  * Fully tested with the Keene USB FM Transmitter and the v4l2-compliance tool.
23  */
24 
25 #include <linux/module.h>	/* Modules 			*/
26 #include <linux/init.h>		/* Initdata			*/
27 #include <linux/ioport.h>	/* request_region		*/
28 #include <linux/delay.h>	/* udelay			*/
29 #include <linux/videodev2.h>	/* kernel radio structs		*/
30 #include <linux/mutex.h>
31 #include <linux/io.h>		/* outb, outb_p			*/
32 #include <linux/slab.h>
33 #include <media/v4l2-ioctl.h>
34 #include <media/v4l2-device.h>
35 #include "radio-isa.h"
36 
37 /*
38  * Module info.
39  */
40 
41 MODULE_AUTHOR("Jonas Munsin, Pekka Seppänen <pexu@kapsi.fi>");
42 MODULE_DESCRIPTION("A driver for the GemTek Radio card.");
43 MODULE_LICENSE("GPL");
44 MODULE_VERSION("1.0.0");
45 
46 /*
47  * Module params.
48  */
49 
50 #ifndef CONFIG_RADIO_GEMTEK_PORT
51 #define CONFIG_RADIO_GEMTEK_PORT -1
52 #endif
53 #ifndef CONFIG_RADIO_GEMTEK_PROBE
54 #define CONFIG_RADIO_GEMTEK_PROBE 1
55 #endif
56 
57 #define GEMTEK_MAX 4
58 
59 static bool probe = CONFIG_RADIO_GEMTEK_PROBE;
60 static bool hardmute;
61 static int io[GEMTEK_MAX] = { [0] = CONFIG_RADIO_GEMTEK_PORT,
62 			      [1 ... (GEMTEK_MAX - 1)] = -1 };
63 static int radio_nr[GEMTEK_MAX]	= { [0 ... (GEMTEK_MAX - 1)] = -1 };
64 
65 module_param(probe, bool, 0444);
66 MODULE_PARM_DESC(probe, "Enable automatic device probing.");
67 
68 module_param(hardmute, bool, 0644);
69 MODULE_PARM_DESC(hardmute, "Enable 'hard muting' by shutting down PLL, may "
70 	 "reduce static noise.");
71 
72 module_param_array(io, int, NULL, 0444);
73 MODULE_PARM_DESC(io, "Force I/O ports for the GemTek Radio card if automatic "
74 	 "probing is disabled or fails. The most common I/O ports are: 0x20c "
75 	 "0x30c, 0x24c or 0x34c (0x20c, 0x248 and 0x28c have been reported to "
76 	 "work for the combined sound/radiocard).");
77 
78 module_param_array(radio_nr, int, NULL, 0444);
79 MODULE_PARM_DESC(radio_nr, "Radio device numbers");
80 
81 /*
82  * Frequency calculation constants.  Intermediate frequency 10.52 MHz (nominal
83  * value 10.7 MHz), reference divisor 6.39 kHz (nominal 6.25 kHz).
84  */
85 #define FSCALE		8
86 #define IF_OFFSET	((unsigned int)(10.52 * 16000 * (1<<FSCALE)))
87 #define REF_FREQ	((unsigned int)(6.39 * 16 * (1<<FSCALE)))
88 
89 #define GEMTEK_CK		0x01	/* Clock signal			*/
90 #define GEMTEK_DA		0x02	/* Serial data			*/
91 #define GEMTEK_CE		0x04	/* Chip enable			*/
92 #define GEMTEK_NS		0x08	/* No signal			*/
93 #define GEMTEK_MT		0x10	/* Line mute			*/
94 #define GEMTEK_STDF_3_125_KHZ	0x01	/* Standard frequency 3.125 kHz	*/
95 #define GEMTEK_PLL_OFF		0x07	/* PLL off			*/
96 
97 #define BU2614_BUS_SIZE	32	/* BU2614 / BU2614FS bus size		*/
98 
99 #define SHORT_DELAY 5		/* usec */
100 #define LONG_DELAY 75		/* usec */
101 
102 struct gemtek {
103 	struct radio_isa_card isa;
104 	bool muted;
105 	u32 bu2614data;
106 };
107 
108 #define BU2614_FREQ_BITS 	16 /* D0..D15, Frequency data		*/
109 #define BU2614_PORT_BITS	3 /* P0..P2, Output port control data	*/
110 #define BU2614_VOID_BITS	4 /* unused 				*/
111 #define BU2614_FMES_BITS	1 /* CT, Frequency measurement beginning data */
112 #define BU2614_STDF_BITS	3 /* R0..R2, Standard frequency data	*/
113 #define BU2614_SWIN_BITS	1 /* S, Switch between FMIN / AMIN	*/
114 #define BU2614_SWAL_BITS        1 /* PS, Swallow counter division (AMIN only)*/
115 #define BU2614_VOID2_BITS	1 /* unused				*/
116 #define BU2614_FMUN_BITS	1 /* GT, Frequency measurement time & unlock */
117 #define BU2614_TEST_BITS	1 /* TS, Test data is input		*/
118 
119 #define BU2614_FREQ_SHIFT 	0
120 #define BU2614_PORT_SHIFT	(BU2614_FREQ_BITS + BU2614_FREQ_SHIFT)
121 #define BU2614_VOID_SHIFT	(BU2614_PORT_BITS + BU2614_PORT_SHIFT)
122 #define BU2614_FMES_SHIFT	(BU2614_VOID_BITS + BU2614_VOID_SHIFT)
123 #define BU2614_STDF_SHIFT	(BU2614_FMES_BITS + BU2614_FMES_SHIFT)
124 #define BU2614_SWIN_SHIFT	(BU2614_STDF_BITS + BU2614_STDF_SHIFT)
125 #define BU2614_SWAL_SHIFT	(BU2614_SWIN_BITS + BU2614_SWIN_SHIFT)
126 #define BU2614_VOID2_SHIFT	(BU2614_SWAL_BITS + BU2614_SWAL_SHIFT)
127 #define BU2614_FMUN_SHIFT	(BU2614_VOID2_BITS + BU2614_VOID2_SHIFT)
128 #define BU2614_TEST_SHIFT	(BU2614_FMUN_BITS + BU2614_FMUN_SHIFT)
129 
130 #define MKMASK(field)	(((1<<BU2614_##field##_BITS) - 1) << \
131 			BU2614_##field##_SHIFT)
132 #define BU2614_PORT_MASK	MKMASK(PORT)
133 #define BU2614_FREQ_MASK	MKMASK(FREQ)
134 #define BU2614_VOID_MASK	MKMASK(VOID)
135 #define BU2614_FMES_MASK	MKMASK(FMES)
136 #define BU2614_STDF_MASK	MKMASK(STDF)
137 #define BU2614_SWIN_MASK	MKMASK(SWIN)
138 #define BU2614_SWAL_MASK	MKMASK(SWAL)
139 #define BU2614_VOID2_MASK	MKMASK(VOID2)
140 #define BU2614_FMUN_MASK	MKMASK(FMUN)
141 #define BU2614_TEST_MASK	MKMASK(TEST)
142 
143 /*
144  * Set data which will be sent to BU2614FS.
145  */
146 #define gemtek_bu2614_set(dev, field, data) ((dev)->bu2614data = \
147 	((dev)->bu2614data & ~field##_MASK) | ((data) << field##_SHIFT))
148 
149 /*
150  * Transmit settings to BU2614FS over GemTek IC.
151  */
152 static void gemtek_bu2614_transmit(struct gemtek *gt)
153 {
154 	struct radio_isa_card *isa = &gt->isa;
155 	int i, bit, q, mute;
156 
157 	mute = gt->muted ? GEMTEK_MT : 0x00;
158 
159 	outb_p(mute | GEMTEK_CE | GEMTEK_DA | GEMTEK_CK, isa->io);
160 	udelay(LONG_DELAY);
161 
162 	for (i = 0, q = gt->bu2614data; i < 32; i++, q >>= 1) {
163 		bit = (q & 1) ? GEMTEK_DA : 0;
164 		outb_p(mute | GEMTEK_CE | bit, isa->io);
165 		udelay(SHORT_DELAY);
166 		outb_p(mute | GEMTEK_CE | bit | GEMTEK_CK, isa->io);
167 		udelay(SHORT_DELAY);
168 	}
169 
170 	outb_p(mute | GEMTEK_DA | GEMTEK_CK, isa->io);
171 	udelay(SHORT_DELAY);
172 }
173 
174 /*
175  * Calculate divisor from FM-frequency for BU2614FS (3.125 KHz STDF expected).
176  */
177 static unsigned long gemtek_convfreq(unsigned long freq)
178 {
179 	return ((freq << FSCALE) + IF_OFFSET + REF_FREQ / 2) / REF_FREQ;
180 }
181 
182 static struct radio_isa_card *gemtek_alloc(void)
183 {
184 	struct gemtek *gt = kzalloc(sizeof(*gt), GFP_KERNEL);
185 
186 	if (gt)
187 		gt->muted = true;
188 	return gt ? &gt->isa : NULL;
189 }
190 
191 /*
192  * Set FM-frequency.
193  */
194 static int gemtek_s_frequency(struct radio_isa_card *isa, u32 freq)
195 {
196 	struct gemtek *gt = container_of(isa, struct gemtek, isa);
197 
198 	if (hardmute && gt->muted)
199 		return 0;
200 
201 	gemtek_bu2614_set(gt, BU2614_PORT, 0);
202 	gemtek_bu2614_set(gt, BU2614_FMES, 0);
203 	gemtek_bu2614_set(gt, BU2614_SWIN, 0);	/* FM-mode	*/
204 	gemtek_bu2614_set(gt, BU2614_SWAL, 0);
205 	gemtek_bu2614_set(gt, BU2614_FMUN, 1);	/* GT bit set	*/
206 	gemtek_bu2614_set(gt, BU2614_TEST, 0);
207 	gemtek_bu2614_set(gt, BU2614_STDF, GEMTEK_STDF_3_125_KHZ);
208 	gemtek_bu2614_set(gt, BU2614_FREQ, gemtek_convfreq(freq));
209 	gemtek_bu2614_transmit(gt);
210 	return 0;
211 }
212 
213 /*
214  * Set mute flag.
215  */
216 static int gemtek_s_mute_volume(struct radio_isa_card *isa, bool mute, int vol)
217 {
218 	struct gemtek *gt = container_of(isa, struct gemtek, isa);
219 	int i;
220 
221 	gt->muted = mute;
222 	if (hardmute) {
223 		if (!mute)
224 			return gemtek_s_frequency(isa, isa->freq);
225 
226 		/* Turn off PLL, disable data output */
227 		gemtek_bu2614_set(gt, BU2614_PORT, 0);
228 		gemtek_bu2614_set(gt, BU2614_FMES, 0);	/* CT bit off	*/
229 		gemtek_bu2614_set(gt, BU2614_SWIN, 0);	/* FM-mode	*/
230 		gemtek_bu2614_set(gt, BU2614_SWAL, 0);
231 		gemtek_bu2614_set(gt, BU2614_FMUN, 0);	/* GT bit off	*/
232 		gemtek_bu2614_set(gt, BU2614_TEST, 0);
233 		gemtek_bu2614_set(gt, BU2614_STDF, GEMTEK_PLL_OFF);
234 		gemtek_bu2614_set(gt, BU2614_FREQ, 0);
235 		gemtek_bu2614_transmit(gt);
236 		return 0;
237 	}
238 
239 	/* Read bus contents (CE, CK and DA). */
240 	i = inb_p(isa->io);
241 	/* Write it back with mute flag set. */
242 	outb_p((i >> 5) | (mute ? GEMTEK_MT : 0), isa->io);
243 	udelay(SHORT_DELAY);
244 	return 0;
245 }
246 
247 static u32 gemtek_g_rxsubchans(struct radio_isa_card *isa)
248 {
249 	if (inb_p(isa->io) & GEMTEK_NS)
250 		return V4L2_TUNER_SUB_MONO;
251 	return V4L2_TUNER_SUB_STEREO;
252 }
253 
254 /*
255  * Check if requested card acts like GemTek Radio card.
256  */
257 static bool gemtek_probe(struct radio_isa_card *isa, int io)
258 {
259 	int i, q;
260 
261 	q = inb_p(io);	/* Read bus contents before probing. */
262 	/* Try to turn on CE, CK and DA respectively and check if card responds
263 	   properly. */
264 	for (i = 0; i < 3; ++i) {
265 		outb_p(1 << i, io);
266 		udelay(SHORT_DELAY);
267 
268 		if ((inb_p(io) & ~GEMTEK_NS) != (0x17 | (1 << (i + 5))))
269 			return false;
270 	}
271 	outb_p(q >> 5, io);	/* Write bus contents back. */
272 	udelay(SHORT_DELAY);
273 	return true;
274 }
275 
276 static const struct radio_isa_ops gemtek_ops = {
277 	.alloc = gemtek_alloc,
278 	.probe = gemtek_probe,
279 	.s_mute_volume = gemtek_s_mute_volume,
280 	.s_frequency = gemtek_s_frequency,
281 	.g_rxsubchans = gemtek_g_rxsubchans,
282 };
283 
284 static const int gemtek_ioports[] = { 0x20c, 0x30c, 0x24c, 0x34c, 0x248, 0x28c };
285 
286 static struct radio_isa_driver gemtek_driver = {
287 	.driver = {
288 		.match		= radio_isa_match,
289 		.probe		= radio_isa_probe,
290 		.remove		= radio_isa_remove,
291 		.driver		= {
292 			.name	= "radio-gemtek",
293 		},
294 	},
295 	.io_params = io,
296 	.radio_nr_params = radio_nr,
297 	.io_ports = gemtek_ioports,
298 	.num_of_io_ports = ARRAY_SIZE(gemtek_ioports),
299 	.region_size = 1,
300 	.card = "GemTek Radio",
301 	.ops = &gemtek_ops,
302 	.has_stereo = true,
303 };
304 
305 static int __init gemtek_init(void)
306 {
307 	gemtek_driver.probe = probe;
308 	return isa_register_driver(&gemtek_driver.driver, GEMTEK_MAX);
309 }
310 
311 static void __exit gemtek_exit(void)
312 {
313 	hardmute = 1;	/* Turn off PLL */
314 	isa_unregister_driver(&gemtek_driver.driver);
315 }
316 
317 module_init(gemtek_init);
318 module_exit(gemtek_exit);
319