1 /*
2  *    Support for AltoBeam GB20600 (a.k.a DMB-TH) demodulator
3  *    ATBM8830, ATBM8831
4  *
5  *    Copyright (C) 2009 David T.L. Wong <davidtlwong@gmail.com>
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 #include <asm/div64.h>
23 #include "dvb_frontend.h"
24 
25 #include "atbm8830.h"
26 #include "atbm8830_priv.h"
27 
28 #define dprintk(args...) \
29 	do { \
30 		if (debug) \
31 			printk(KERN_DEBUG "atbm8830: " args); \
32 	} while (0)
33 
34 static int debug;
35 
36 module_param(debug, int, 0644);
37 MODULE_PARM_DESC(debug, "Turn on/off frontend debugging (default:off).");
38 
39 static int atbm8830_write_reg(struct atbm_state *priv, u16 reg, u8 data)
40 {
41 	int ret = 0;
42 	u8 dev_addr;
43 	u8 buf1[] = { reg >> 8, reg & 0xFF };
44 	u8 buf2[] = { data };
45 	struct i2c_msg msg1 = { .flags = 0, .buf = buf1, .len = 2 };
46 	struct i2c_msg msg2 = { .flags = 0, .buf = buf2, .len = 1 };
47 
48 	dev_addr = priv->config->demod_address;
49 	msg1.addr = dev_addr;
50 	msg2.addr = dev_addr;
51 
52 	if (debug >= 2)
53 		dprintk("%s: reg=0x%04X, data=0x%02X\n", __func__, reg, data);
54 
55 	ret = i2c_transfer(priv->i2c, &msg1, 1);
56 	if (ret != 1)
57 		return -EIO;
58 
59 	ret = i2c_transfer(priv->i2c, &msg2, 1);
60 	return (ret != 1) ? -EIO : 0;
61 }
62 
63 static int atbm8830_read_reg(struct atbm_state *priv, u16 reg, u8 *p_data)
64 {
65 	int ret;
66 	u8 dev_addr;
67 
68 	u8 buf1[] = { reg >> 8, reg & 0xFF };
69 	u8 buf2[] = { 0 };
70 	struct i2c_msg msg1 = { .flags = 0, .buf = buf1, .len = 2 };
71 	struct i2c_msg msg2 = { .flags = I2C_M_RD, .buf = buf2, .len = 1 };
72 
73 	dev_addr = priv->config->demod_address;
74 	msg1.addr = dev_addr;
75 	msg2.addr = dev_addr;
76 
77 	ret = i2c_transfer(priv->i2c, &msg1, 1);
78 	if (ret != 1) {
79 		dprintk("%s: error reg=0x%04x, ret=%i\n", __func__, reg, ret);
80 		return -EIO;
81 	}
82 
83 	ret = i2c_transfer(priv->i2c, &msg2, 1);
84 	if (ret != 1)
85 		return -EIO;
86 
87 	*p_data = buf2[0];
88 	if (debug >= 2)
89 		dprintk("%s: reg=0x%04X, data=0x%02X\n",
90 			__func__, reg, buf2[0]);
91 
92 	return 0;
93 }
94 
95 /* Lock register latch so that multi-register read is atomic */
96 static inline int atbm8830_reglatch_lock(struct atbm_state *priv, int lock)
97 {
98 	return atbm8830_write_reg(priv, REG_READ_LATCH, lock ? 1 : 0);
99 }
100 
101 static int set_osc_freq(struct atbm_state *priv, u32 freq /*in kHz*/)
102 {
103 	u32 val;
104 	u64 t;
105 
106 	/* 0x100000 * freq / 30.4MHz */
107 	t = (u64)0x100000 * freq;
108 	do_div(t, 30400);
109 	val = t;
110 
111 	atbm8830_write_reg(priv, REG_OSC_CLK, val);
112 	atbm8830_write_reg(priv, REG_OSC_CLK + 1, val >> 8);
113 	atbm8830_write_reg(priv, REG_OSC_CLK + 2, val >> 16);
114 
115 	return 0;
116 }
117 
118 static int set_if_freq(struct atbm_state *priv, u32 freq /*in kHz*/)
119 {
120 
121 	u32 fs = priv->config->osc_clk_freq;
122 	u64 t;
123 	u32 val;
124 	u8 dat;
125 
126 	if (freq != 0) {
127 		/* 2 * PI * (freq - fs) / fs * (2 ^ 22) */
128 		t = (u64) 2 * 31416 * (freq - fs);
129 		t <<= 22;
130 		do_div(t, fs);
131 		do_div(t, 1000);
132 		val = t;
133 
134 		atbm8830_write_reg(priv, REG_TUNER_BASEBAND, 1);
135 		atbm8830_write_reg(priv, REG_IF_FREQ, val);
136 		atbm8830_write_reg(priv, REG_IF_FREQ+1, val >> 8);
137 		atbm8830_write_reg(priv, REG_IF_FREQ+2, val >> 16);
138 
139 		atbm8830_read_reg(priv, REG_ADC_CONFIG, &dat);
140 		dat &= 0xFC;
141 		atbm8830_write_reg(priv, REG_ADC_CONFIG, dat);
142 	} else {
143 		/* Zero IF */
144 		atbm8830_write_reg(priv, REG_TUNER_BASEBAND, 0);
145 
146 		atbm8830_read_reg(priv, REG_ADC_CONFIG, &dat);
147 		dat &= 0xFC;
148 		dat |= 0x02;
149 		atbm8830_write_reg(priv, REG_ADC_CONFIG, dat);
150 
151 		if (priv->config->zif_swap_iq)
152 			atbm8830_write_reg(priv, REG_SWAP_I_Q, 0x03);
153 		else
154 			atbm8830_write_reg(priv, REG_SWAP_I_Q, 0x01);
155 	}
156 
157 	return 0;
158 }
159 
160 static int is_locked(struct atbm_state *priv, u8 *locked)
161 {
162 	u8 status;
163 
164 	atbm8830_read_reg(priv, REG_LOCK_STATUS, &status);
165 
166 	if (locked != NULL)
167 		*locked = (status == 1);
168 	return 0;
169 }
170 
171 static int set_agc_config(struct atbm_state *priv,
172 	u8 min, u8 max, u8 hold_loop)
173 {
174 	/* no effect if both min and max are zero */
175 	if (!min && !max)
176 	    return 0;
177 
178 	atbm8830_write_reg(priv, REG_AGC_MIN, min);
179 	atbm8830_write_reg(priv, REG_AGC_MAX, max);
180 	atbm8830_write_reg(priv, REG_AGC_HOLD_LOOP, hold_loop);
181 
182 	return 0;
183 }
184 
185 static int set_static_channel_mode(struct atbm_state *priv)
186 {
187 	int i;
188 
189 	for (i = 0; i < 5; i++)
190 		atbm8830_write_reg(priv, 0x099B + i, 0x08);
191 
192 	atbm8830_write_reg(priv, 0x095B, 0x7F);
193 	atbm8830_write_reg(priv, 0x09CB, 0x01);
194 	atbm8830_write_reg(priv, 0x09CC, 0x7F);
195 	atbm8830_write_reg(priv, 0x09CD, 0x7F);
196 	atbm8830_write_reg(priv, 0x0E01, 0x20);
197 
198 	/* For single carrier */
199 	atbm8830_write_reg(priv, 0x0B03, 0x0A);
200 	atbm8830_write_reg(priv, 0x0935, 0x10);
201 	atbm8830_write_reg(priv, 0x0936, 0x08);
202 	atbm8830_write_reg(priv, 0x093E, 0x08);
203 	atbm8830_write_reg(priv, 0x096E, 0x06);
204 
205 	/* frame_count_max0 */
206 	atbm8830_write_reg(priv, 0x0B09, 0x00);
207 	/* frame_count_max1 */
208 	atbm8830_write_reg(priv, 0x0B0A, 0x08);
209 
210 	return 0;
211 }
212 
213 static int set_ts_config(struct atbm_state *priv)
214 {
215 	const struct atbm8830_config *cfg = priv->config;
216 
217 	/*Set parallel/serial ts mode*/
218 	atbm8830_write_reg(priv, REG_TS_SERIAL, cfg->serial_ts ? 1 : 0);
219 	atbm8830_write_reg(priv, REG_TS_CLK_MODE, cfg->serial_ts ? 1 : 0);
220 	/*Set ts sampling edge*/
221 	atbm8830_write_reg(priv, REG_TS_SAMPLE_EDGE,
222 		cfg->ts_sampling_edge ? 1 : 0);
223 	/*Set ts clock freerun*/
224 	atbm8830_write_reg(priv, REG_TS_CLK_FREERUN,
225 		cfg->ts_clk_gated ? 0 : 1);
226 
227 	return 0;
228 }
229 
230 static int atbm8830_init(struct dvb_frontend *fe)
231 {
232 	struct atbm_state *priv = fe->demodulator_priv;
233 	const struct atbm8830_config *cfg = priv->config;
234 
235 	/*Set oscillator frequency*/
236 	set_osc_freq(priv, cfg->osc_clk_freq);
237 
238 	/*Set IF frequency*/
239 	set_if_freq(priv, cfg->if_freq);
240 
241 	/*Set AGC Config*/
242 	set_agc_config(priv, cfg->agc_min, cfg->agc_max,
243 		cfg->agc_hold_loop);
244 
245 	/*Set static channel mode*/
246 	set_static_channel_mode(priv);
247 
248 	set_ts_config(priv);
249 	/*Turn off DSP reset*/
250 	atbm8830_write_reg(priv, 0x000A, 0);
251 
252 	/*SW version test*/
253 	atbm8830_write_reg(priv, 0x020C, 11);
254 
255 	/* Run */
256 	atbm8830_write_reg(priv, REG_DEMOD_RUN, 1);
257 
258 	return 0;
259 }
260 
261 
262 static void atbm8830_release(struct dvb_frontend *fe)
263 {
264 	struct atbm_state *state = fe->demodulator_priv;
265 	dprintk("%s\n", __func__);
266 
267 	kfree(state);
268 }
269 
270 static int atbm8830_set_fe(struct dvb_frontend *fe)
271 {
272 	struct atbm_state *priv = fe->demodulator_priv;
273 	int i;
274 	u8 locked = 0;
275 	dprintk("%s\n", __func__);
276 
277 	/* set frequency */
278 	if (fe->ops.tuner_ops.set_params) {
279 		if (fe->ops.i2c_gate_ctrl)
280 			fe->ops.i2c_gate_ctrl(fe, 1);
281 		fe->ops.tuner_ops.set_params(fe);
282 		if (fe->ops.i2c_gate_ctrl)
283 			fe->ops.i2c_gate_ctrl(fe, 0);
284 	}
285 
286 	/* start auto lock */
287 	for (i = 0; i < 10; i++) {
288 		mdelay(100);
289 		dprintk("Try %d\n", i);
290 		is_locked(priv, &locked);
291 		if (locked != 0) {
292 			dprintk("ATBM8830 locked!\n");
293 			break;
294 		}
295 	}
296 
297 	return 0;
298 }
299 
300 static int atbm8830_get_fe(struct dvb_frontend *fe)
301 {
302 	struct dtv_frontend_properties *c = &fe->dtv_property_cache;
303 	dprintk("%s\n", __func__);
304 
305 	/* TODO: get real readings from device */
306 	/* inversion status */
307 	c->inversion = INVERSION_OFF;
308 
309 	/* bandwidth */
310 	c->bandwidth_hz = 8000000;
311 
312 	c->code_rate_HP = FEC_AUTO;
313 	c->code_rate_LP = FEC_AUTO;
314 
315 	c->modulation = QAM_AUTO;
316 
317 	/* transmission mode */
318 	c->transmission_mode = TRANSMISSION_MODE_AUTO;
319 
320 	/* guard interval */
321 	c->guard_interval = GUARD_INTERVAL_AUTO;
322 
323 	/* hierarchy */
324 	c->hierarchy = HIERARCHY_NONE;
325 
326 	return 0;
327 }
328 
329 static int atbm8830_get_tune_settings(struct dvb_frontend *fe,
330 	struct dvb_frontend_tune_settings *fesettings)
331 {
332 	fesettings->min_delay_ms = 0;
333 	fesettings->step_size = 0;
334 	fesettings->max_drift = 0;
335 	return 0;
336 }
337 
338 static int atbm8830_read_status(struct dvb_frontend *fe,
339 				enum fe_status *fe_status)
340 {
341 	struct atbm_state *priv = fe->demodulator_priv;
342 	u8 locked = 0;
343 	u8 agc_locked = 0;
344 
345 	dprintk("%s\n", __func__);
346 	*fe_status = 0;
347 
348 	is_locked(priv, &locked);
349 	if (locked) {
350 		*fe_status |= FE_HAS_SIGNAL | FE_HAS_CARRIER |
351 			FE_HAS_VITERBI | FE_HAS_SYNC | FE_HAS_LOCK;
352 	}
353 	dprintk("%s: fe_status=0x%x\n", __func__, *fe_status);
354 
355 	atbm8830_read_reg(priv, REG_AGC_LOCK, &agc_locked);
356 	dprintk("AGC Lock: %d\n", agc_locked);
357 
358 	return 0;
359 }
360 
361 static int atbm8830_read_ber(struct dvb_frontend *fe, u32 *ber)
362 {
363 	struct atbm_state *priv = fe->demodulator_priv;
364 	u32 frame_err;
365 	u8 t;
366 
367 	dprintk("%s\n", __func__);
368 
369 	atbm8830_reglatch_lock(priv, 1);
370 
371 	atbm8830_read_reg(priv, REG_FRAME_ERR_CNT + 1, &t);
372 	frame_err = t & 0x7F;
373 	frame_err <<= 8;
374 	atbm8830_read_reg(priv, REG_FRAME_ERR_CNT, &t);
375 	frame_err |= t;
376 
377 	atbm8830_reglatch_lock(priv, 0);
378 
379 	*ber = frame_err * 100 / 32767;
380 
381 	dprintk("%s: ber=0x%x\n", __func__, *ber);
382 	return 0;
383 }
384 
385 static int atbm8830_read_signal_strength(struct dvb_frontend *fe, u16 *signal)
386 {
387 	struct atbm_state *priv = fe->demodulator_priv;
388 	u32 pwm;
389 	u8 t;
390 
391 	dprintk("%s\n", __func__);
392 	atbm8830_reglatch_lock(priv, 1);
393 
394 	atbm8830_read_reg(priv, REG_AGC_PWM_VAL + 1, &t);
395 	pwm = t & 0x03;
396 	pwm <<= 8;
397 	atbm8830_read_reg(priv, REG_AGC_PWM_VAL, &t);
398 	pwm |= t;
399 
400 	atbm8830_reglatch_lock(priv, 0);
401 
402 	dprintk("AGC PWM = 0x%02X\n", pwm);
403 	pwm = 0x400 - pwm;
404 
405 	*signal = pwm * 0x10000 / 0x400;
406 
407 	return 0;
408 }
409 
410 static int atbm8830_read_snr(struct dvb_frontend *fe, u16 *snr)
411 {
412 	dprintk("%s\n", __func__);
413 	*snr = 0;
414 	return 0;
415 }
416 
417 static int atbm8830_read_ucblocks(struct dvb_frontend *fe, u32 *ucblocks)
418 {
419 	dprintk("%s\n", __func__);
420 	*ucblocks = 0;
421 	return 0;
422 }
423 
424 static int atbm8830_i2c_gate_ctrl(struct dvb_frontend *fe, int enable)
425 {
426 	struct atbm_state *priv = fe->demodulator_priv;
427 
428 	return atbm8830_write_reg(priv, REG_I2C_GATE, enable ? 1 : 0);
429 }
430 
431 static struct dvb_frontend_ops atbm8830_ops = {
432 	.delsys = { SYS_DTMB },
433 	.info = {
434 		.name = "AltoBeam ATBM8830/8831 DMB-TH",
435 		.frequency_min = 474000000,
436 		.frequency_max = 858000000,
437 		.frequency_stepsize = 10000,
438 		.caps =
439 			FE_CAN_FEC_AUTO |
440 			FE_CAN_QAM_AUTO |
441 			FE_CAN_TRANSMISSION_MODE_AUTO |
442 			FE_CAN_GUARD_INTERVAL_AUTO
443 	},
444 
445 	.release = atbm8830_release,
446 
447 	.init = atbm8830_init,
448 	.sleep = NULL,
449 	.write = NULL,
450 	.i2c_gate_ctrl = atbm8830_i2c_gate_ctrl,
451 
452 	.set_frontend = atbm8830_set_fe,
453 	.get_frontend = atbm8830_get_fe,
454 	.get_tune_settings = atbm8830_get_tune_settings,
455 
456 	.read_status = atbm8830_read_status,
457 	.read_ber = atbm8830_read_ber,
458 	.read_signal_strength = atbm8830_read_signal_strength,
459 	.read_snr = atbm8830_read_snr,
460 	.read_ucblocks = atbm8830_read_ucblocks,
461 };
462 
463 struct dvb_frontend *atbm8830_attach(const struct atbm8830_config *config,
464 	struct i2c_adapter *i2c)
465 {
466 	struct atbm_state *priv = NULL;
467 	u8 data = 0;
468 
469 	dprintk("%s()\n", __func__);
470 
471 	if (config == NULL || i2c == NULL)
472 		return NULL;
473 
474 	priv = kzalloc(sizeof(struct atbm_state), GFP_KERNEL);
475 	if (priv == NULL)
476 		goto error_out;
477 
478 	priv->config = config;
479 	priv->i2c = i2c;
480 
481 	/* check if the demod is there */
482 	if (atbm8830_read_reg(priv, REG_CHIP_ID, &data) != 0) {
483 		dprintk("%s atbm8830/8831 not found at i2c addr 0x%02X\n",
484 			__func__, priv->config->demod_address);
485 		goto error_out;
486 	}
487 	dprintk("atbm8830 chip id: 0x%02X\n", data);
488 
489 	memcpy(&priv->frontend.ops, &atbm8830_ops,
490 	       sizeof(struct dvb_frontend_ops));
491 	priv->frontend.demodulator_priv = priv;
492 
493 	atbm8830_init(&priv->frontend);
494 
495 	atbm8830_i2c_gate_ctrl(&priv->frontend, 1);
496 
497 	return &priv->frontend;
498 
499 error_out:
500 	dprintk("%s() error_out\n", __func__);
501 	kfree(priv);
502 	return NULL;
503 
504 }
505 EXPORT_SYMBOL(atbm8830_attach);
506 
507 MODULE_DESCRIPTION("AltoBeam ATBM8830/8831 GB20600 demodulator driver");
508 MODULE_AUTHOR("David T. L. Wong <davidtlwong@gmail.com>");
509 MODULE_LICENSE("GPL");
510