1 /*
2     Conexant cx22700 DVB OFDM demodulator driver
3 
4     Copyright (C) 2001-2002 Convergence Integrated Media GmbH
5 	Holger Waechtler <holger@convergence.de>
6 
7     This program is free software; you can redistribute it and/or modify
8     it under the terms of the GNU General Public License as published by
9     the Free Software Foundation; either version 2 of the License, or
10     (at your option) any later version.
11 
12     This program is distributed in the hope that it will be useful,
13     but WITHOUT ANY WARRANTY; without even the implied warranty of
14     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15     GNU General Public License for more details.
16 
17     You should have received a copy of the GNU General Public License
18     along with this program; if not, write to the Free Software
19     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 
21 */
22 
23 #include <linux/kernel.h>
24 #include <linux/init.h>
25 #include <linux/module.h>
26 #include <linux/string.h>
27 #include <linux/slab.h>
28 #include "dvb_frontend.h"
29 #include "cx22700.h"
30 
31 
32 struct cx22700_state {
33 
34 	struct i2c_adapter* i2c;
35 
36 	const struct cx22700_config* config;
37 
38 	struct dvb_frontend frontend;
39 };
40 
41 
42 static int debug;
43 #define dprintk(args...) \
44 	do { \
45 		if (debug) printk(KERN_DEBUG "cx22700: " args); \
46 	} while (0)
47 
48 static u8 init_tab [] = {
49 	0x04, 0x10,
50 	0x05, 0x09,
51 	0x06, 0x00,
52 	0x08, 0x04,
53 	0x09, 0x00,
54 	0x0a, 0x01,
55 	0x15, 0x40,
56 	0x16, 0x10,
57 	0x17, 0x87,
58 	0x18, 0x17,
59 	0x1a, 0x10,
60 	0x25, 0x04,
61 	0x2e, 0x00,
62 	0x39, 0x00,
63 	0x3a, 0x04,
64 	0x45, 0x08,
65 	0x46, 0x02,
66 	0x47, 0x05,
67 };
68 
69 
70 static int cx22700_writereg (struct cx22700_state* state, u8 reg, u8 data)
71 {
72 	int ret;
73 	u8 buf [] = { reg, data };
74 	struct i2c_msg msg = { .addr = state->config->demod_address, .flags = 0, .buf = buf, .len = 2 };
75 
76 	dprintk ("%s\n", __func__);
77 
78 	ret = i2c_transfer (state->i2c, &msg, 1);
79 
80 	if (ret != 1)
81 		printk("%s: writereg error (reg == 0x%02x, val == 0x%02x, ret == %i)\n",
82 			__func__, reg, data, ret);
83 
84 	return (ret != 1) ? -1 : 0;
85 }
86 
87 static int cx22700_readreg (struct cx22700_state* state, u8 reg)
88 {
89 	int ret;
90 	u8 b0 [] = { reg };
91 	u8 b1 [] = { 0 };
92 	struct i2c_msg msg [] = { { .addr = state->config->demod_address, .flags = 0, .buf = b0, .len = 1 },
93 			   { .addr = state->config->demod_address, .flags = I2C_M_RD, .buf = b1, .len = 1 } };
94 
95 	dprintk ("%s\n", __func__);
96 
97 	ret = i2c_transfer (state->i2c, msg, 2);
98 
99 	if (ret != 2) return -EIO;
100 
101 	return b1[0];
102 }
103 
104 static int cx22700_set_inversion (struct cx22700_state* state, int inversion)
105 {
106 	u8 val;
107 
108 	dprintk ("%s\n", __func__);
109 
110 	switch (inversion) {
111 	case INVERSION_AUTO:
112 		return -EOPNOTSUPP;
113 	case INVERSION_ON:
114 		val = cx22700_readreg (state, 0x09);
115 		return cx22700_writereg (state, 0x09, val | 0x01);
116 	case INVERSION_OFF:
117 		val = cx22700_readreg (state, 0x09);
118 		return cx22700_writereg (state, 0x09, val & 0xfe);
119 	default:
120 		return -EINVAL;
121 	}
122 }
123 
124 static int cx22700_set_tps(struct cx22700_state *state,
125 			   struct dtv_frontend_properties *p)
126 {
127 	static const u8 qam_tab [4] = { 0, 1, 0, 2 };
128 	static const u8 fec_tab [6] = { 0, 1, 2, 0, 3, 4 };
129 	u8 val;
130 
131 	dprintk ("%s\n", __func__);
132 
133 	if (p->code_rate_HP < FEC_1_2 || p->code_rate_HP > FEC_7_8)
134 		return -EINVAL;
135 
136 	if (p->code_rate_LP < FEC_1_2 || p->code_rate_LP > FEC_7_8)
137 		return -EINVAL;
138 
139 	if (p->code_rate_HP == FEC_4_5 || p->code_rate_LP == FEC_4_5)
140 		return -EINVAL;
141 
142 	if ((int)p->guard_interval < GUARD_INTERVAL_1_32 ||
143 	    p->guard_interval > GUARD_INTERVAL_1_4)
144 		return -EINVAL;
145 
146 	if (p->transmission_mode != TRANSMISSION_MODE_2K &&
147 	    p->transmission_mode != TRANSMISSION_MODE_8K)
148 		return -EINVAL;
149 
150 	if (p->modulation != QPSK &&
151 	    p->modulation != QAM_16 &&
152 	    p->modulation != QAM_64)
153 		return -EINVAL;
154 
155 	if ((int)p->hierarchy < HIERARCHY_NONE ||
156 	    p->hierarchy > HIERARCHY_4)
157 		return -EINVAL;
158 
159 	if (p->bandwidth_hz > 8000000 || p->bandwidth_hz < 6000000)
160 		return -EINVAL;
161 
162 	if (p->bandwidth_hz == 7000000)
163 		cx22700_writereg (state, 0x09, cx22700_readreg (state, 0x09 | 0x10));
164 	else
165 		cx22700_writereg (state, 0x09, cx22700_readreg (state, 0x09 & ~0x10));
166 
167 	val = qam_tab[p->modulation - QPSK];
168 	val |= p->hierarchy - HIERARCHY_NONE;
169 
170 	cx22700_writereg (state, 0x04, val);
171 
172 	if (p->code_rate_HP - FEC_1_2 >= sizeof(fec_tab) ||
173 	    p->code_rate_LP - FEC_1_2 >= sizeof(fec_tab))
174 		return -EINVAL;
175 	val = fec_tab[p->code_rate_HP - FEC_1_2] << 3;
176 	val |= fec_tab[p->code_rate_LP - FEC_1_2];
177 
178 	cx22700_writereg (state, 0x05, val);
179 
180 	val = (p->guard_interval - GUARD_INTERVAL_1_32) << 2;
181 	val |= p->transmission_mode - TRANSMISSION_MODE_2K;
182 
183 	cx22700_writereg (state, 0x06, val);
184 
185 	cx22700_writereg (state, 0x08, 0x04 | 0x02);  /* use user tps parameters */
186 	cx22700_writereg (state, 0x08, 0x04);         /* restart acquisition */
187 
188 	return 0;
189 }
190 
191 static int cx22700_get_tps(struct cx22700_state *state,
192 			   struct dtv_frontend_properties *p)
193 {
194 	static const enum fe_modulation qam_tab[3] = { QPSK, QAM_16, QAM_64 };
195 	static const enum fe_code_rate fec_tab[5] = {
196 		FEC_1_2, FEC_2_3, FEC_3_4, FEC_5_6, FEC_7_8
197 	};
198 	u8 val;
199 
200 	dprintk ("%s\n", __func__);
201 
202 	if (!(cx22700_readreg(state, 0x07) & 0x20))  /*  tps valid? */
203 		return -EAGAIN;
204 
205 	val = cx22700_readreg (state, 0x01);
206 
207 	if ((val & 0x7) > 4)
208 		p->hierarchy = HIERARCHY_AUTO;
209 	else
210 		p->hierarchy = HIERARCHY_NONE + (val & 0x7);
211 
212 	if (((val >> 3) & 0x3) > 2)
213 		p->modulation = QAM_AUTO;
214 	else
215 		p->modulation = qam_tab[(val >> 3) & 0x3];
216 
217 	val = cx22700_readreg (state, 0x02);
218 
219 	if (((val >> 3) & 0x07) > 4)
220 		p->code_rate_HP = FEC_AUTO;
221 	else
222 		p->code_rate_HP = fec_tab[(val >> 3) & 0x07];
223 
224 	if ((val & 0x07) > 4)
225 		p->code_rate_LP = FEC_AUTO;
226 	else
227 		p->code_rate_LP = fec_tab[val & 0x07];
228 
229 	val = cx22700_readreg (state, 0x03);
230 
231 	p->guard_interval = GUARD_INTERVAL_1_32 + ((val >> 6) & 0x3);
232 	p->transmission_mode = TRANSMISSION_MODE_2K + ((val >> 5) & 0x1);
233 
234 	return 0;
235 }
236 
237 static int cx22700_init (struct dvb_frontend* fe)
238 
239 {	struct cx22700_state* state = fe->demodulator_priv;
240 	int i;
241 
242 	dprintk("cx22700_init: init chip\n");
243 
244 	cx22700_writereg (state, 0x00, 0x02);   /*  soft reset */
245 	cx22700_writereg (state, 0x00, 0x00);
246 
247 	msleep(10);
248 
249 	for (i=0; i<sizeof(init_tab); i+=2)
250 		cx22700_writereg (state, init_tab[i], init_tab[i+1]);
251 
252 	cx22700_writereg (state, 0x00, 0x01);
253 
254 	return 0;
255 }
256 
257 static int cx22700_read_status(struct dvb_frontend *fe, enum fe_status *status)
258 {
259 	struct cx22700_state* state = fe->demodulator_priv;
260 
261 	u16 rs_ber = (cx22700_readreg (state, 0x0d) << 9)
262 		   | (cx22700_readreg (state, 0x0e) << 1);
263 	u8 sync = cx22700_readreg (state, 0x07);
264 
265 	*status = 0;
266 
267 	if (rs_ber < 0xff00)
268 		*status |= FE_HAS_SIGNAL;
269 
270 	if (sync & 0x20)
271 		*status |= FE_HAS_CARRIER;
272 
273 	if (sync & 0x10)
274 		*status |= FE_HAS_VITERBI;
275 
276 	if (sync & 0x10)
277 		*status |= FE_HAS_SYNC;
278 
279 	if (*status == 0x0f)
280 		*status |= FE_HAS_LOCK;
281 
282 	return 0;
283 }
284 
285 static int cx22700_read_ber(struct dvb_frontend* fe, u32* ber)
286 {
287 	struct cx22700_state* state = fe->demodulator_priv;
288 
289 	*ber = cx22700_readreg (state, 0x0c) & 0x7f;
290 	cx22700_writereg (state, 0x0c, 0x00);
291 
292 	return 0;
293 }
294 
295 static int cx22700_read_signal_strength(struct dvb_frontend* fe, u16* signal_strength)
296 {
297 	struct cx22700_state* state = fe->demodulator_priv;
298 
299 	u16 rs_ber = (cx22700_readreg (state, 0x0d) << 9)
300 		   | (cx22700_readreg (state, 0x0e) << 1);
301 	*signal_strength = ~rs_ber;
302 
303 	return 0;
304 }
305 
306 static int cx22700_read_snr(struct dvb_frontend* fe, u16* snr)
307 {
308 	struct cx22700_state* state = fe->demodulator_priv;
309 
310 	u16 rs_ber = (cx22700_readreg (state, 0x0d) << 9)
311 		   | (cx22700_readreg (state, 0x0e) << 1);
312 	*snr = ~rs_ber;
313 
314 	return 0;
315 }
316 
317 static int cx22700_read_ucblocks(struct dvb_frontend* fe, u32* ucblocks)
318 {
319 	struct cx22700_state* state = fe->demodulator_priv;
320 
321 	*ucblocks = cx22700_readreg (state, 0x0f);
322 	cx22700_writereg (state, 0x0f, 0x00);
323 
324 	return 0;
325 }
326 
327 static int cx22700_set_frontend(struct dvb_frontend *fe)
328 {
329 	struct dtv_frontend_properties *c = &fe->dtv_property_cache;
330 	struct cx22700_state* state = fe->demodulator_priv;
331 
332 	cx22700_writereg (state, 0x00, 0x02); /* XXX CHECKME: soft reset*/
333 	cx22700_writereg (state, 0x00, 0x00);
334 
335 	if (fe->ops.tuner_ops.set_params) {
336 		fe->ops.tuner_ops.set_params(fe);
337 		if (fe->ops.i2c_gate_ctrl) fe->ops.i2c_gate_ctrl(fe, 0);
338 	}
339 
340 	cx22700_set_inversion(state, c->inversion);
341 	cx22700_set_tps(state, c);
342 	cx22700_writereg (state, 0x37, 0x01);  /* PAL loop filter off */
343 	cx22700_writereg (state, 0x00, 0x01);  /* restart acquire */
344 
345 	return 0;
346 }
347 
348 static int cx22700_get_frontend(struct dvb_frontend *fe,
349 				struct dtv_frontend_properties *c)
350 {
351 	struct cx22700_state* state = fe->demodulator_priv;
352 	u8 reg09 = cx22700_readreg (state, 0x09);
353 
354 	c->inversion = reg09 & 0x1 ? INVERSION_ON : INVERSION_OFF;
355 	return cx22700_get_tps(state, c);
356 }
357 
358 static int cx22700_i2c_gate_ctrl(struct dvb_frontend* fe, int enable)
359 {
360 	struct cx22700_state* state = fe->demodulator_priv;
361 
362 	if (enable) {
363 		return cx22700_writereg(state, 0x0a, 0x00);
364 	} else {
365 		return cx22700_writereg(state, 0x0a, 0x01);
366 	}
367 }
368 
369 static int cx22700_get_tune_settings(struct dvb_frontend* fe, struct dvb_frontend_tune_settings* fesettings)
370 {
371 	fesettings->min_delay_ms = 150;
372 	fesettings->step_size = 166667;
373 	fesettings->max_drift = 166667*2;
374 	return 0;
375 }
376 
377 static void cx22700_release(struct dvb_frontend* fe)
378 {
379 	struct cx22700_state* state = fe->demodulator_priv;
380 	kfree(state);
381 }
382 
383 static const struct dvb_frontend_ops cx22700_ops;
384 
385 struct dvb_frontend* cx22700_attach(const struct cx22700_config* config,
386 				    struct i2c_adapter* i2c)
387 {
388 	struct cx22700_state* state = NULL;
389 
390 	/* allocate memory for the internal state */
391 	state = kzalloc(sizeof(struct cx22700_state), GFP_KERNEL);
392 	if (state == NULL) goto error;
393 
394 	/* setup the state */
395 	state->config = config;
396 	state->i2c = i2c;
397 
398 	/* check if the demod is there */
399 	if (cx22700_readreg(state, 0x07) < 0) goto error;
400 
401 	/* create dvb_frontend */
402 	memcpy(&state->frontend.ops, &cx22700_ops, sizeof(struct dvb_frontend_ops));
403 	state->frontend.demodulator_priv = state;
404 	return &state->frontend;
405 
406 error:
407 	kfree(state);
408 	return NULL;
409 }
410 
411 static const struct dvb_frontend_ops cx22700_ops = {
412 	.delsys = { SYS_DVBT },
413 	.info = {
414 		.name			= "Conexant CX22700 DVB-T",
415 		.frequency_min		= 470000000,
416 		.frequency_max		= 860000000,
417 		.frequency_stepsize	= 166667,
418 		.caps = FE_CAN_FEC_1_2 | FE_CAN_FEC_2_3 | FE_CAN_FEC_3_4 |
419 		      FE_CAN_FEC_5_6 | FE_CAN_FEC_7_8 | FE_CAN_FEC_AUTO |
420 		      FE_CAN_QPSK | FE_CAN_QAM_16 | FE_CAN_QAM_64 |
421 		      FE_CAN_RECOVER
422 	},
423 
424 	.release = cx22700_release,
425 
426 	.init = cx22700_init,
427 	.i2c_gate_ctrl = cx22700_i2c_gate_ctrl,
428 
429 	.set_frontend = cx22700_set_frontend,
430 	.get_frontend = cx22700_get_frontend,
431 	.get_tune_settings = cx22700_get_tune_settings,
432 
433 	.read_status = cx22700_read_status,
434 	.read_ber = cx22700_read_ber,
435 	.read_signal_strength = cx22700_read_signal_strength,
436 	.read_snr = cx22700_read_snr,
437 	.read_ucblocks = cx22700_read_ucblocks,
438 };
439 
440 module_param(debug, int, 0644);
441 MODULE_PARM_DESC(debug, "Turn on/off frontend debugging (default:off).");
442 
443 MODULE_DESCRIPTION("Conexant CX22700 DVB-T Demodulator driver");
444 MODULE_AUTHOR("Holger Waechtler");
445 MODULE_LICENSE("GPL");
446 
447 EXPORT_SYMBOL(cx22700_attach);
448