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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 dvb_ofdm_parameters * p)124 static int cx22700_set_tps (struct cx22700_state *state, struct dvb_ofdm_parameters *p)
125 {
126 	static const u8 qam_tab [4] = { 0, 1, 0, 2 };
127 	static const u8 fec_tab [6] = { 0, 1, 2, 0, 3, 4 };
128 	u8 val;
129 
130 	dprintk ("%s\n", __func__);
131 
132 	if (p->code_rate_HP < FEC_1_2 || p->code_rate_HP > FEC_7_8)
133 		return -EINVAL;
134 
135 	if (p->code_rate_LP < FEC_1_2 || p->code_rate_LP > FEC_7_8)
136 		return -EINVAL;
137 
138 	if (p->code_rate_HP == FEC_4_5 || p->code_rate_LP == FEC_4_5)
139 		return -EINVAL;
140 
141 	if (p->guard_interval < GUARD_INTERVAL_1_32 ||
142 	    p->guard_interval > GUARD_INTERVAL_1_4)
143 		return -EINVAL;
144 
145 	if (p->transmission_mode != TRANSMISSION_MODE_2K &&
146 	    p->transmission_mode != TRANSMISSION_MODE_8K)
147 		return -EINVAL;
148 
149 	if (p->constellation != QPSK &&
150 	    p->constellation != QAM_16 &&
151 	    p->constellation != QAM_64)
152 		return -EINVAL;
153 
154 	if (p->hierarchy_information < HIERARCHY_NONE ||
155 	    p->hierarchy_information > HIERARCHY_4)
156 		return -EINVAL;
157 
158 	if (p->bandwidth < BANDWIDTH_8_MHZ && p->bandwidth > BANDWIDTH_6_MHZ)
159 		return -EINVAL;
160 
161 	if (p->bandwidth == BANDWIDTH_7_MHZ)
162 		cx22700_writereg (state, 0x09, cx22700_readreg (state, 0x09 | 0x10));
163 	else
164 		cx22700_writereg (state, 0x09, cx22700_readreg (state, 0x09 & ~0x10));
165 
166 	val = qam_tab[p->constellation - QPSK];
167 	val |= p->hierarchy_information - HIERARCHY_NONE;
168 
169 	cx22700_writereg (state, 0x04, val);
170 
171 	val = fec_tab[p->code_rate_HP - FEC_1_2] << 3;
172 	val |= fec_tab[p->code_rate_LP - FEC_1_2];
173 
174 	cx22700_writereg (state, 0x05, val);
175 
176 	val = (p->guard_interval - GUARD_INTERVAL_1_32) << 2;
177 	val |= p->transmission_mode - TRANSMISSION_MODE_2K;
178 
179 	cx22700_writereg (state, 0x06, val);
180 
181 	cx22700_writereg (state, 0x08, 0x04 | 0x02);  /* use user tps parameters */
182 	cx22700_writereg (state, 0x08, 0x04);         /* restart aquisition */
183 
184 	return 0;
185 }
186 
cx22700_get_tps(struct cx22700_state * state,struct dvb_ofdm_parameters * p)187 static int cx22700_get_tps (struct cx22700_state* state, struct dvb_ofdm_parameters *p)
188 {
189 	static const fe_modulation_t qam_tab [3] = { QPSK, QAM_16, QAM_64 };
190 	static const fe_code_rate_t fec_tab [5] = { FEC_1_2, FEC_2_3, FEC_3_4,
191 						    FEC_5_6, FEC_7_8 };
192 	u8 val;
193 
194 	dprintk ("%s\n", __func__);
195 
196 	if (!(cx22700_readreg(state, 0x07) & 0x20))  /*  tps valid? */
197 		return -EAGAIN;
198 
199 	val = cx22700_readreg (state, 0x01);
200 
201 	if ((val & 0x7) > 4)
202 		p->hierarchy_information = HIERARCHY_AUTO;
203 	else
204 		p->hierarchy_information = HIERARCHY_NONE + (val & 0x7);
205 
206 	if (((val >> 3) & 0x3) > 2)
207 		p->constellation = QAM_AUTO;
208 	else
209 		p->constellation = qam_tab[(val >> 3) & 0x3];
210 
211 	val = cx22700_readreg (state, 0x02);
212 
213 	if (((val >> 3) & 0x07) > 4)
214 		p->code_rate_HP = FEC_AUTO;
215 	else
216 		p->code_rate_HP = fec_tab[(val >> 3) & 0x07];
217 
218 	if ((val & 0x07) > 4)
219 		p->code_rate_LP = FEC_AUTO;
220 	else
221 		p->code_rate_LP = fec_tab[val & 0x07];
222 
223 	val = cx22700_readreg (state, 0x03);
224 
225 	p->guard_interval = GUARD_INTERVAL_1_32 + ((val >> 6) & 0x3);
226 	p->transmission_mode = TRANSMISSION_MODE_2K + ((val >> 5) & 0x1);
227 
228 	return 0;
229 }
230 
cx22700_init(struct dvb_frontend * fe)231 static int cx22700_init (struct dvb_frontend* fe)
232 
233 {	struct cx22700_state* state = fe->demodulator_priv;
234 	int i;
235 
236 	dprintk("cx22700_init: init chip\n");
237 
238 	cx22700_writereg (state, 0x00, 0x02);   /*  soft reset */
239 	cx22700_writereg (state, 0x00, 0x00);
240 
241 	msleep(10);
242 
243 	for (i=0; i<sizeof(init_tab); i+=2)
244 		cx22700_writereg (state, init_tab[i], init_tab[i+1]);
245 
246 	cx22700_writereg (state, 0x00, 0x01);
247 
248 	return 0;
249 }
250 
cx22700_read_status(struct dvb_frontend * fe,fe_status_t * status)251 static int cx22700_read_status(struct dvb_frontend* fe, fe_status_t* status)
252 {
253 	struct cx22700_state* state = fe->demodulator_priv;
254 
255 	u16 rs_ber = (cx22700_readreg (state, 0x0d) << 9)
256 		   | (cx22700_readreg (state, 0x0e) << 1);
257 	u8 sync = cx22700_readreg (state, 0x07);
258 
259 	*status = 0;
260 
261 	if (rs_ber < 0xff00)
262 		*status |= FE_HAS_SIGNAL;
263 
264 	if (sync & 0x20)
265 		*status |= FE_HAS_CARRIER;
266 
267 	if (sync & 0x10)
268 		*status |= FE_HAS_VITERBI;
269 
270 	if (sync & 0x10)
271 		*status |= FE_HAS_SYNC;
272 
273 	if (*status == 0x0f)
274 		*status |= FE_HAS_LOCK;
275 
276 	return 0;
277 }
278 
cx22700_read_ber(struct dvb_frontend * fe,u32 * ber)279 static int cx22700_read_ber(struct dvb_frontend* fe, u32* ber)
280 {
281 	struct cx22700_state* state = fe->demodulator_priv;
282 
283 	*ber = cx22700_readreg (state, 0x0c) & 0x7f;
284 	cx22700_writereg (state, 0x0c, 0x00);
285 
286 	return 0;
287 }
288 
cx22700_read_signal_strength(struct dvb_frontend * fe,u16 * signal_strength)289 static int cx22700_read_signal_strength(struct dvb_frontend* fe, u16* signal_strength)
290 {
291 	struct cx22700_state* state = fe->demodulator_priv;
292 
293 	u16 rs_ber = (cx22700_readreg (state, 0x0d) << 9)
294 		   | (cx22700_readreg (state, 0x0e) << 1);
295 	*signal_strength = ~rs_ber;
296 
297 	return 0;
298 }
299 
cx22700_read_snr(struct dvb_frontend * fe,u16 * snr)300 static int cx22700_read_snr(struct dvb_frontend* fe, u16* snr)
301 {
302 	struct cx22700_state* state = fe->demodulator_priv;
303 
304 	u16 rs_ber = (cx22700_readreg (state, 0x0d) << 9)
305 		   | (cx22700_readreg (state, 0x0e) << 1);
306 	*snr = ~rs_ber;
307 
308 	return 0;
309 }
310 
cx22700_read_ucblocks(struct dvb_frontend * fe,u32 * ucblocks)311 static int cx22700_read_ucblocks(struct dvb_frontend* fe, u32* ucblocks)
312 {
313 	struct cx22700_state* state = fe->demodulator_priv;
314 
315 	*ucblocks = cx22700_readreg (state, 0x0f);
316 	cx22700_writereg (state, 0x0f, 0x00);
317 
318 	return 0;
319 }
320 
cx22700_set_frontend(struct dvb_frontend * fe,struct dvb_frontend_parameters * p)321 static int cx22700_set_frontend(struct dvb_frontend* fe, struct dvb_frontend_parameters *p)
322 {
323 	struct cx22700_state* state = fe->demodulator_priv;
324 
325 	cx22700_writereg (state, 0x00, 0x02); /* XXX CHECKME: soft reset*/
326 	cx22700_writereg (state, 0x00, 0x00);
327 
328 	if (fe->ops.tuner_ops.set_params) {
329 		fe->ops.tuner_ops.set_params(fe, p);
330 		if (fe->ops.i2c_gate_ctrl) fe->ops.i2c_gate_ctrl(fe, 0);
331 	}
332 
333 	cx22700_set_inversion (state, p->inversion);
334 	cx22700_set_tps (state, &p->u.ofdm);
335 	cx22700_writereg (state, 0x37, 0x01);  /* PAL loop filter off */
336 	cx22700_writereg (state, 0x00, 0x01);  /* restart acquire */
337 
338 	return 0;
339 }
340 
cx22700_get_frontend(struct dvb_frontend * fe,struct dvb_frontend_parameters * p)341 static int cx22700_get_frontend(struct dvb_frontend* fe, struct dvb_frontend_parameters *p)
342 {
343 	struct cx22700_state* state = fe->demodulator_priv;
344 	u8 reg09 = cx22700_readreg (state, 0x09);
345 
346 	p->inversion = reg09 & 0x1 ? INVERSION_ON : INVERSION_OFF;
347 	return cx22700_get_tps (state, &p->u.ofdm);
348 }
349 
cx22700_i2c_gate_ctrl(struct dvb_frontend * fe,int enable)350 static int cx22700_i2c_gate_ctrl(struct dvb_frontend* fe, int enable)
351 {
352 	struct cx22700_state* state = fe->demodulator_priv;
353 
354 	if (enable) {
355 		return cx22700_writereg(state, 0x0a, 0x00);
356 	} else {
357 		return cx22700_writereg(state, 0x0a, 0x01);
358 	}
359 }
360 
cx22700_get_tune_settings(struct dvb_frontend * fe,struct dvb_frontend_tune_settings * fesettings)361 static int cx22700_get_tune_settings(struct dvb_frontend* fe, struct dvb_frontend_tune_settings* fesettings)
362 {
363 	fesettings->min_delay_ms = 150;
364 	fesettings->step_size = 166667;
365 	fesettings->max_drift = 166667*2;
366 	return 0;
367 }
368 
cx22700_release(struct dvb_frontend * fe)369 static void cx22700_release(struct dvb_frontend* fe)
370 {
371 	struct cx22700_state* state = fe->demodulator_priv;
372 	kfree(state);
373 }
374 
375 static struct dvb_frontend_ops cx22700_ops;
376 
cx22700_attach(const struct cx22700_config * config,struct i2c_adapter * i2c)377 struct dvb_frontend* cx22700_attach(const struct cx22700_config* config,
378 				    struct i2c_adapter* i2c)
379 {
380 	struct cx22700_state* state = NULL;
381 
382 	/* allocate memory for the internal state */
383 	state = kmalloc(sizeof(struct cx22700_state), GFP_KERNEL);
384 	if (state == NULL) goto error;
385 
386 	/* setup the state */
387 	state->config = config;
388 	state->i2c = i2c;
389 
390 	/* check if the demod is there */
391 	if (cx22700_readreg(state, 0x07) < 0) goto error;
392 
393 	/* create dvb_frontend */
394 	memcpy(&state->frontend.ops, &cx22700_ops, sizeof(struct dvb_frontend_ops));
395 	state->frontend.demodulator_priv = state;
396 	return &state->frontend;
397 
398 error:
399 	kfree(state);
400 	return NULL;
401 }
402 
403 static struct dvb_frontend_ops cx22700_ops = {
404 
405 	.info = {
406 		.name			= "Conexant CX22700 DVB-T",
407 		.type			= FE_OFDM,
408 		.frequency_min		= 470000000,
409 		.frequency_max		= 860000000,
410 		.frequency_stepsize	= 166667,
411 		.caps = FE_CAN_FEC_1_2 | FE_CAN_FEC_2_3 | FE_CAN_FEC_3_4 |
412 		      FE_CAN_FEC_5_6 | FE_CAN_FEC_7_8 | FE_CAN_FEC_AUTO |
413 		      FE_CAN_QPSK | FE_CAN_QAM_16 | FE_CAN_QAM_64 |
414 		      FE_CAN_RECOVER
415 	},
416 
417 	.release = cx22700_release,
418 
419 	.init = cx22700_init,
420 	.i2c_gate_ctrl = cx22700_i2c_gate_ctrl,
421 
422 	.set_frontend = cx22700_set_frontend,
423 	.get_frontend = cx22700_get_frontend,
424 	.get_tune_settings = cx22700_get_tune_settings,
425 
426 	.read_status = cx22700_read_status,
427 	.read_ber = cx22700_read_ber,
428 	.read_signal_strength = cx22700_read_signal_strength,
429 	.read_snr = cx22700_read_snr,
430 	.read_ucblocks = cx22700_read_ucblocks,
431 };
432 
433 module_param(debug, int, 0644);
434 MODULE_PARM_DESC(debug, "Turn on/off frontend debugging (default:off).");
435 
436 MODULE_DESCRIPTION("Conexant CX22700 DVB-T Demodulator driver");
437 MODULE_AUTHOR("Holger Waechtler");
438 MODULE_LICENSE("GPL");
439 
440 EXPORT_SYMBOL(cx22700_attach);
441