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
32struct cx22700_state {
33
34	struct i2c_adapter* i2c;
35
36	const struct cx22700_config* config;
37
38	struct dvb_frontend frontend;
39};
40
41
42static int debug;
43#define dprintk(args...) \
44	do { \
45		if (debug) printk(KERN_DEBUG "cx22700: " args); \
46	} while (0)
47
48static 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
70static 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
87static 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
104static 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
124static 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
191static 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
237static 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
257static 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
285static 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
295static 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
306static 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
317static 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
327static 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
348static int cx22700_get_frontend(struct dvb_frontend *fe)
349{
350	struct dtv_frontend_properties *c = &fe->dtv_property_cache;
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
358static 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
369static 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
377static void cx22700_release(struct dvb_frontend* fe)
378{
379	struct cx22700_state* state = fe->demodulator_priv;
380	kfree(state);
381}
382
383static struct dvb_frontend_ops cx22700_ops;
384
385struct 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
406error:
407	kfree(state);
408	return NULL;
409}
410
411static 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
440module_param(debug, int, 0644);
441MODULE_PARM_DESC(debug, "Turn on/off frontend debugging (default:off).");
442
443MODULE_DESCRIPTION("Conexant CX22700 DVB-T Demodulator driver");
444MODULE_AUTHOR("Holger Waechtler");
445MODULE_LICENSE("GPL");
446
447EXPORT_SYMBOL(cx22700_attach);
448