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 
cx22700_writereg(struct cx22700_state * state,u8 reg,u8 data)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 
cx22700_readreg(struct cx22700_state * state,u8 reg)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 
cx22700_set_inversion(struct cx22700_state * state,int inversion)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 
cx22700_set_tps(struct cx22700_state * state,struct dtv_frontend_properties * p)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 (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 (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 	val = fec_tab[p->code_rate_HP - FEC_1_2] << 3;
173 	val |= fec_tab[p->code_rate_LP - FEC_1_2];
174 
175 	cx22700_writereg (state, 0x05, val);
176 
177 	val = (p->guard_interval - GUARD_INTERVAL_1_32) << 2;
178 	val |= p->transmission_mode - TRANSMISSION_MODE_2K;
179 
180 	cx22700_writereg (state, 0x06, val);
181 
182 	cx22700_writereg (state, 0x08, 0x04 | 0x02);  /* use user tps parameters */
183 	cx22700_writereg (state, 0x08, 0x04);         /* restart acquisition */
184 
185 	return 0;
186 }
187 
cx22700_get_tps(struct cx22700_state * state,struct dtv_frontend_properties * p)188 static int cx22700_get_tps(struct cx22700_state *state,
189 			   struct dtv_frontend_properties *p)
190 {
191 	static const fe_modulation_t qam_tab [3] = { QPSK, QAM_16, QAM_64 };
192 	static const fe_code_rate_t fec_tab [5] = { FEC_1_2, FEC_2_3, FEC_3_4,
193 						    FEC_5_6, FEC_7_8 };
194 	u8 val;
195 
196 	dprintk ("%s\n", __func__);
197 
198 	if (!(cx22700_readreg(state, 0x07) & 0x20))  /*  tps valid? */
199 		return -EAGAIN;
200 
201 	val = cx22700_readreg (state, 0x01);
202 
203 	if ((val & 0x7) > 4)
204 		p->hierarchy = HIERARCHY_AUTO;
205 	else
206 		p->hierarchy = HIERARCHY_NONE + (val & 0x7);
207 
208 	if (((val >> 3) & 0x3) > 2)
209 		p->modulation = QAM_AUTO;
210 	else
211 		p->modulation = qam_tab[(val >> 3) & 0x3];
212 
213 	val = cx22700_readreg (state, 0x02);
214 
215 	if (((val >> 3) & 0x07) > 4)
216 		p->code_rate_HP = FEC_AUTO;
217 	else
218 		p->code_rate_HP = fec_tab[(val >> 3) & 0x07];
219 
220 	if ((val & 0x07) > 4)
221 		p->code_rate_LP = FEC_AUTO;
222 	else
223 		p->code_rate_LP = fec_tab[val & 0x07];
224 
225 	val = cx22700_readreg (state, 0x03);
226 
227 	p->guard_interval = GUARD_INTERVAL_1_32 + ((val >> 6) & 0x3);
228 	p->transmission_mode = TRANSMISSION_MODE_2K + ((val >> 5) & 0x1);
229 
230 	return 0;
231 }
232 
cx22700_init(struct dvb_frontend * fe)233 static int cx22700_init (struct dvb_frontend* fe)
234 
235 {	struct cx22700_state* state = fe->demodulator_priv;
236 	int i;
237 
238 	dprintk("cx22700_init: init chip\n");
239 
240 	cx22700_writereg (state, 0x00, 0x02);   /*  soft reset */
241 	cx22700_writereg (state, 0x00, 0x00);
242 
243 	msleep(10);
244 
245 	for (i=0; i<sizeof(init_tab); i+=2)
246 		cx22700_writereg (state, init_tab[i], init_tab[i+1]);
247 
248 	cx22700_writereg (state, 0x00, 0x01);
249 
250 	return 0;
251 }
252 
cx22700_read_status(struct dvb_frontend * fe,fe_status_t * status)253 static int cx22700_read_status(struct dvb_frontend* fe, fe_status_t* status)
254 {
255 	struct cx22700_state* state = fe->demodulator_priv;
256 
257 	u16 rs_ber = (cx22700_readreg (state, 0x0d) << 9)
258 		   | (cx22700_readreg (state, 0x0e) << 1);
259 	u8 sync = cx22700_readreg (state, 0x07);
260 
261 	*status = 0;
262 
263 	if (rs_ber < 0xff00)
264 		*status |= FE_HAS_SIGNAL;
265 
266 	if (sync & 0x20)
267 		*status |= FE_HAS_CARRIER;
268 
269 	if (sync & 0x10)
270 		*status |= FE_HAS_VITERBI;
271 
272 	if (sync & 0x10)
273 		*status |= FE_HAS_SYNC;
274 
275 	if (*status == 0x0f)
276 		*status |= FE_HAS_LOCK;
277 
278 	return 0;
279 }
280 
cx22700_read_ber(struct dvb_frontend * fe,u32 * ber)281 static int cx22700_read_ber(struct dvb_frontend* fe, u32* ber)
282 {
283 	struct cx22700_state* state = fe->demodulator_priv;
284 
285 	*ber = cx22700_readreg (state, 0x0c) & 0x7f;
286 	cx22700_writereg (state, 0x0c, 0x00);
287 
288 	return 0;
289 }
290 
cx22700_read_signal_strength(struct dvb_frontend * fe,u16 * signal_strength)291 static int cx22700_read_signal_strength(struct dvb_frontend* fe, u16* signal_strength)
292 {
293 	struct cx22700_state* state = fe->demodulator_priv;
294 
295 	u16 rs_ber = (cx22700_readreg (state, 0x0d) << 9)
296 		   | (cx22700_readreg (state, 0x0e) << 1);
297 	*signal_strength = ~rs_ber;
298 
299 	return 0;
300 }
301 
cx22700_read_snr(struct dvb_frontend * fe,u16 * snr)302 static int cx22700_read_snr(struct dvb_frontend* fe, u16* snr)
303 {
304 	struct cx22700_state* state = fe->demodulator_priv;
305 
306 	u16 rs_ber = (cx22700_readreg (state, 0x0d) << 9)
307 		   | (cx22700_readreg (state, 0x0e) << 1);
308 	*snr = ~rs_ber;
309 
310 	return 0;
311 }
312 
cx22700_read_ucblocks(struct dvb_frontend * fe,u32 * ucblocks)313 static int cx22700_read_ucblocks(struct dvb_frontend* fe, u32* ucblocks)
314 {
315 	struct cx22700_state* state = fe->demodulator_priv;
316 
317 	*ucblocks = cx22700_readreg (state, 0x0f);
318 	cx22700_writereg (state, 0x0f, 0x00);
319 
320 	return 0;
321 }
322 
cx22700_set_frontend(struct dvb_frontend * fe)323 static int cx22700_set_frontend(struct dvb_frontend *fe)
324 {
325 	struct dtv_frontend_properties *c = &fe->dtv_property_cache;
326 	struct cx22700_state* state = fe->demodulator_priv;
327 
328 	cx22700_writereg (state, 0x00, 0x02); /* XXX CHECKME: soft reset*/
329 	cx22700_writereg (state, 0x00, 0x00);
330 
331 	if (fe->ops.tuner_ops.set_params) {
332 		fe->ops.tuner_ops.set_params(fe);
333 		if (fe->ops.i2c_gate_ctrl) fe->ops.i2c_gate_ctrl(fe, 0);
334 	}
335 
336 	cx22700_set_inversion(state, c->inversion);
337 	cx22700_set_tps(state, c);
338 	cx22700_writereg (state, 0x37, 0x01);  /* PAL loop filter off */
339 	cx22700_writereg (state, 0x00, 0x01);  /* restart acquire */
340 
341 	return 0;
342 }
343 
cx22700_get_frontend(struct dvb_frontend * fe)344 static int cx22700_get_frontend(struct dvb_frontend *fe)
345 {
346 	struct dtv_frontend_properties *c = &fe->dtv_property_cache;
347 	struct cx22700_state* state = fe->demodulator_priv;
348 	u8 reg09 = cx22700_readreg (state, 0x09);
349 
350 	c->inversion = reg09 & 0x1 ? INVERSION_ON : INVERSION_OFF;
351 	return cx22700_get_tps(state, c);
352 }
353 
cx22700_i2c_gate_ctrl(struct dvb_frontend * fe,int enable)354 static int cx22700_i2c_gate_ctrl(struct dvb_frontend* fe, int enable)
355 {
356 	struct cx22700_state* state = fe->demodulator_priv;
357 
358 	if (enable) {
359 		return cx22700_writereg(state, 0x0a, 0x00);
360 	} else {
361 		return cx22700_writereg(state, 0x0a, 0x01);
362 	}
363 }
364 
cx22700_get_tune_settings(struct dvb_frontend * fe,struct dvb_frontend_tune_settings * fesettings)365 static int cx22700_get_tune_settings(struct dvb_frontend* fe, struct dvb_frontend_tune_settings* fesettings)
366 {
367 	fesettings->min_delay_ms = 150;
368 	fesettings->step_size = 166667;
369 	fesettings->max_drift = 166667*2;
370 	return 0;
371 }
372 
cx22700_release(struct dvb_frontend * fe)373 static void cx22700_release(struct dvb_frontend* fe)
374 {
375 	struct cx22700_state* state = fe->demodulator_priv;
376 	kfree(state);
377 }
378 
379 static struct dvb_frontend_ops cx22700_ops;
380 
cx22700_attach(const struct cx22700_config * config,struct i2c_adapter * i2c)381 struct dvb_frontend* cx22700_attach(const struct cx22700_config* config,
382 				    struct i2c_adapter* i2c)
383 {
384 	struct cx22700_state* state = NULL;
385 
386 	/* allocate memory for the internal state */
387 	state = kzalloc(sizeof(struct cx22700_state), GFP_KERNEL);
388 	if (state == NULL) goto error;
389 
390 	/* setup the state */
391 	state->config = config;
392 	state->i2c = i2c;
393 
394 	/* check if the demod is there */
395 	if (cx22700_readreg(state, 0x07) < 0) goto error;
396 
397 	/* create dvb_frontend */
398 	memcpy(&state->frontend.ops, &cx22700_ops, sizeof(struct dvb_frontend_ops));
399 	state->frontend.demodulator_priv = state;
400 	return &state->frontend;
401 
402 error:
403 	kfree(state);
404 	return NULL;
405 }
406 
407 static struct dvb_frontend_ops cx22700_ops = {
408 	.delsys = { SYS_DVBT },
409 	.info = {
410 		.name			= "Conexant CX22700 DVB-T",
411 		.frequency_min		= 470000000,
412 		.frequency_max		= 860000000,
413 		.frequency_stepsize	= 166667,
414 		.caps = FE_CAN_FEC_1_2 | FE_CAN_FEC_2_3 | FE_CAN_FEC_3_4 |
415 		      FE_CAN_FEC_5_6 | FE_CAN_FEC_7_8 | FE_CAN_FEC_AUTO |
416 		      FE_CAN_QPSK | FE_CAN_QAM_16 | FE_CAN_QAM_64 |
417 		      FE_CAN_RECOVER
418 	},
419 
420 	.release = cx22700_release,
421 
422 	.init = cx22700_init,
423 	.i2c_gate_ctrl = cx22700_i2c_gate_ctrl,
424 
425 	.set_frontend = cx22700_set_frontend,
426 	.get_frontend = cx22700_get_frontend,
427 	.get_tune_settings = cx22700_get_tune_settings,
428 
429 	.read_status = cx22700_read_status,
430 	.read_ber = cx22700_read_ber,
431 	.read_signal_strength = cx22700_read_signal_strength,
432 	.read_snr = cx22700_read_snr,
433 	.read_ucblocks = cx22700_read_ucblocks,
434 };
435 
436 module_param(debug, int, 0644);
437 MODULE_PARM_DESC(debug, "Turn on/off frontend debugging (default:off).");
438 
439 MODULE_DESCRIPTION("Conexant CX22700 DVB-T Demodulator driver");
440 MODULE_AUTHOR("Holger Waechtler");
441 MODULE_LICENSE("GPL");
442 
443 EXPORT_SYMBOL(cx22700_attach);
444