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 fe_modulation_t qam_tab [3] = { QPSK, QAM_16, QAM_64 };
195 	static const fe_code_rate_t fec_tab [5] = { FEC_1_2, FEC_2_3, FEC_3_4,
196 						    FEC_5_6, FEC_7_8 };
197 	u8 val;
198 
199 	dprintk ("%s\n", __func__);
200 
201 	if (!(cx22700_readreg(state, 0x07) & 0x20))  /*  tps valid? */
202 		return -EAGAIN;
203 
204 	val = cx22700_readreg (state, 0x01);
205 
206 	if ((val & 0x7) > 4)
207 		p->hierarchy = HIERARCHY_AUTO;
208 	else
209 		p->hierarchy = HIERARCHY_NONE + (val & 0x7);
210 
211 	if (((val >> 3) & 0x3) > 2)
212 		p->modulation = QAM_AUTO;
213 	else
214 		p->modulation = qam_tab[(val >> 3) & 0x3];
215 
216 	val = cx22700_readreg (state, 0x02);
217 
218 	if (((val >> 3) & 0x07) > 4)
219 		p->code_rate_HP = FEC_AUTO;
220 	else
221 		p->code_rate_HP = fec_tab[(val >> 3) & 0x07];
222 
223 	if ((val & 0x07) > 4)
224 		p->code_rate_LP = FEC_AUTO;
225 	else
226 		p->code_rate_LP = fec_tab[val & 0x07];
227 
228 	val = cx22700_readreg (state, 0x03);
229 
230 	p->guard_interval = GUARD_INTERVAL_1_32 + ((val >> 6) & 0x3);
231 	p->transmission_mode = TRANSMISSION_MODE_2K + ((val >> 5) & 0x1);
232 
233 	return 0;
234 }
235 
236 static int cx22700_init (struct dvb_frontend* fe)
237 
238 {	struct cx22700_state* state = fe->demodulator_priv;
239 	int i;
240 
241 	dprintk("cx22700_init: init chip\n");
242 
243 	cx22700_writereg (state, 0x00, 0x02);   /*  soft reset */
244 	cx22700_writereg (state, 0x00, 0x00);
245 
246 	msleep(10);
247 
248 	for (i=0; i<sizeof(init_tab); i+=2)
249 		cx22700_writereg (state, init_tab[i], init_tab[i+1]);
250 
251 	cx22700_writereg (state, 0x00, 0x01);
252 
253 	return 0;
254 }
255 
256 static int cx22700_read_status(struct dvb_frontend* fe, fe_status_t* status)
257 {
258 	struct cx22700_state* state = fe->demodulator_priv;
259 
260 	u16 rs_ber = (cx22700_readreg (state, 0x0d) << 9)
261 		   | (cx22700_readreg (state, 0x0e) << 1);
262 	u8 sync = cx22700_readreg (state, 0x07);
263 
264 	*status = 0;
265 
266 	if (rs_ber < 0xff00)
267 		*status |= FE_HAS_SIGNAL;
268 
269 	if (sync & 0x20)
270 		*status |= FE_HAS_CARRIER;
271 
272 	if (sync & 0x10)
273 		*status |= FE_HAS_VITERBI;
274 
275 	if (sync & 0x10)
276 		*status |= FE_HAS_SYNC;
277 
278 	if (*status == 0x0f)
279 		*status |= FE_HAS_LOCK;
280 
281 	return 0;
282 }
283 
284 static int cx22700_read_ber(struct dvb_frontend* fe, u32* ber)
285 {
286 	struct cx22700_state* state = fe->demodulator_priv;
287 
288 	*ber = cx22700_readreg (state, 0x0c) & 0x7f;
289 	cx22700_writereg (state, 0x0c, 0x00);
290 
291 	return 0;
292 }
293 
294 static int cx22700_read_signal_strength(struct dvb_frontend* fe, u16* signal_strength)
295 {
296 	struct cx22700_state* state = fe->demodulator_priv;
297 
298 	u16 rs_ber = (cx22700_readreg (state, 0x0d) << 9)
299 		   | (cx22700_readreg (state, 0x0e) << 1);
300 	*signal_strength = ~rs_ber;
301 
302 	return 0;
303 }
304 
305 static int cx22700_read_snr(struct dvb_frontend* fe, u16* snr)
306 {
307 	struct cx22700_state* state = fe->demodulator_priv;
308 
309 	u16 rs_ber = (cx22700_readreg (state, 0x0d) << 9)
310 		   | (cx22700_readreg (state, 0x0e) << 1);
311 	*snr = ~rs_ber;
312 
313 	return 0;
314 }
315 
316 static int cx22700_read_ucblocks(struct dvb_frontend* fe, u32* ucblocks)
317 {
318 	struct cx22700_state* state = fe->demodulator_priv;
319 
320 	*ucblocks = cx22700_readreg (state, 0x0f);
321 	cx22700_writereg (state, 0x0f, 0x00);
322 
323 	return 0;
324 }
325 
326 static int cx22700_set_frontend(struct dvb_frontend *fe)
327 {
328 	struct dtv_frontend_properties *c = &fe->dtv_property_cache;
329 	struct cx22700_state* state = fe->demodulator_priv;
330 
331 	cx22700_writereg (state, 0x00, 0x02); /* XXX CHECKME: soft reset*/
332 	cx22700_writereg (state, 0x00, 0x00);
333 
334 	if (fe->ops.tuner_ops.set_params) {
335 		fe->ops.tuner_ops.set_params(fe);
336 		if (fe->ops.i2c_gate_ctrl) fe->ops.i2c_gate_ctrl(fe, 0);
337 	}
338 
339 	cx22700_set_inversion(state, c->inversion);
340 	cx22700_set_tps(state, c);
341 	cx22700_writereg (state, 0x37, 0x01);  /* PAL loop filter off */
342 	cx22700_writereg (state, 0x00, 0x01);  /* restart acquire */
343 
344 	return 0;
345 }
346 
347 static int cx22700_get_frontend(struct dvb_frontend *fe)
348 {
349 	struct dtv_frontend_properties *c = &fe->dtv_property_cache;
350 	struct cx22700_state* state = fe->demodulator_priv;
351 	u8 reg09 = cx22700_readreg (state, 0x09);
352 
353 	c->inversion = reg09 & 0x1 ? INVERSION_ON : INVERSION_OFF;
354 	return cx22700_get_tps(state, c);
355 }
356 
357 static int cx22700_i2c_gate_ctrl(struct dvb_frontend* fe, int enable)
358 {
359 	struct cx22700_state* state = fe->demodulator_priv;
360 
361 	if (enable) {
362 		return cx22700_writereg(state, 0x0a, 0x00);
363 	} else {
364 		return cx22700_writereg(state, 0x0a, 0x01);
365 	}
366 }
367 
368 static int cx22700_get_tune_settings(struct dvb_frontend* fe, struct dvb_frontend_tune_settings* fesettings)
369 {
370 	fesettings->min_delay_ms = 150;
371 	fesettings->step_size = 166667;
372 	fesettings->max_drift = 166667*2;
373 	return 0;
374 }
375 
376 static void cx22700_release(struct dvb_frontend* fe)
377 {
378 	struct cx22700_state* state = fe->demodulator_priv;
379 	kfree(state);
380 }
381 
382 static struct dvb_frontend_ops cx22700_ops;
383 
384 struct dvb_frontend* cx22700_attach(const struct cx22700_config* config,
385 				    struct i2c_adapter* i2c)
386 {
387 	struct cx22700_state* state = NULL;
388 
389 	/* allocate memory for the internal state */
390 	state = kzalloc(sizeof(struct cx22700_state), GFP_KERNEL);
391 	if (state == NULL) goto error;
392 
393 	/* setup the state */
394 	state->config = config;
395 	state->i2c = i2c;
396 
397 	/* check if the demod is there */
398 	if (cx22700_readreg(state, 0x07) < 0) goto error;
399 
400 	/* create dvb_frontend */
401 	memcpy(&state->frontend.ops, &cx22700_ops, sizeof(struct dvb_frontend_ops));
402 	state->frontend.demodulator_priv = state;
403 	return &state->frontend;
404 
405 error:
406 	kfree(state);
407 	return NULL;
408 }
409 
410 static struct dvb_frontend_ops cx22700_ops = {
411 	.delsys = { SYS_DVBT },
412 	.info = {
413 		.name			= "Conexant CX22700 DVB-T",
414 		.frequency_min		= 470000000,
415 		.frequency_max		= 860000000,
416 		.frequency_stepsize	= 166667,
417 		.caps = FE_CAN_FEC_1_2 | FE_CAN_FEC_2_3 | FE_CAN_FEC_3_4 |
418 		      FE_CAN_FEC_5_6 | FE_CAN_FEC_7_8 | FE_CAN_FEC_AUTO |
419 		      FE_CAN_QPSK | FE_CAN_QAM_16 | FE_CAN_QAM_64 |
420 		      FE_CAN_RECOVER
421 	},
422 
423 	.release = cx22700_release,
424 
425 	.init = cx22700_init,
426 	.i2c_gate_ctrl = cx22700_i2c_gate_ctrl,
427 
428 	.set_frontend = cx22700_set_frontend,
429 	.get_frontend = cx22700_get_frontend,
430 	.get_tune_settings = cx22700_get_tune_settings,
431 
432 	.read_status = cx22700_read_status,
433 	.read_ber = cx22700_read_ber,
434 	.read_signal_strength = cx22700_read_signal_strength,
435 	.read_snr = cx22700_read_snr,
436 	.read_ucblocks = cx22700_read_ucblocks,
437 };
438 
439 module_param(debug, int, 0644);
440 MODULE_PARM_DESC(debug, "Turn on/off frontend debugging (default:off).");
441 
442 MODULE_DESCRIPTION("Conexant CX22700 DVB-T Demodulator driver");
443 MODULE_AUTHOR("Holger Waechtler");
444 MODULE_LICENSE("GPL");
445 
446 EXPORT_SYMBOL(cx22700_attach);
447