1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3    Driver for the Spase sp887x demodulator
4 */
5 
6 /*
7  * This driver needs external firmware. Please use the command
8  * "<kerneldir>/scripts/get_dvb_firmware sp887x" to
9  * download/extract it, and then copy it to /usr/lib/hotplug/firmware
10  * or /lib/firmware (depending on configuration of firmware hotplug).
11  */
12 #define SP887X_DEFAULT_FIRMWARE "dvb-fe-sp887x.fw"
13 
14 #include <linux/init.h>
15 #include <linux/module.h>
16 #include <linux/device.h>
17 #include <linux/firmware.h>
18 #include <linux/string.h>
19 #include <linux/slab.h>
20 
21 #include <media/dvb_frontend.h>
22 #include "sp887x.h"
23 
24 
25 struct sp887x_state {
26 	struct i2c_adapter* i2c;
27 	const struct sp887x_config* config;
28 	struct dvb_frontend frontend;
29 
30 	/* demodulator private data */
31 	u8 initialised:1;
32 };
33 
34 static int debug;
35 #define dprintk(args...) \
36 	do { \
37 		if (debug) printk(KERN_DEBUG "sp887x: " args); \
38 	} while (0)
39 
40 static int i2c_writebytes (struct sp887x_state* state, u8 *buf, u8 len)
41 {
42 	struct i2c_msg msg = { .addr = state->config->demod_address, .flags = 0, .buf = buf, .len = len };
43 	int err;
44 
45 	if ((err = i2c_transfer (state->i2c, &msg, 1)) != 1) {
46 		printk ("%s: i2c write error (addr %02x, err == %i)\n",
47 			__func__, state->config->demod_address, err);
48 		return -EREMOTEIO;
49 	}
50 
51 	return 0;
52 }
53 
54 static int sp887x_writereg (struct sp887x_state* state, u16 reg, u16 data)
55 {
56 	u8 b0 [] = { reg >> 8 , reg & 0xff, data >> 8, data & 0xff };
57 	struct i2c_msg msg = { .addr = state->config->demod_address, .flags = 0, .buf = b0, .len = 4 };
58 	int ret;
59 
60 	if ((ret = i2c_transfer(state->i2c, &msg, 1)) != 1) {
61 		/*
62 		 *  in case of soft reset we ignore ACK errors...
63 		 */
64 		if (!(reg == 0xf1a && data == 0x000 &&
65 			(ret == -EREMOTEIO || ret == -EFAULT)))
66 		{
67 			printk("%s: writereg error (reg %03x, data %03x, ret == %i)\n",
68 			       __func__, reg & 0xffff, data & 0xffff, ret);
69 			return ret;
70 		}
71 	}
72 
73 	return 0;
74 }
75 
76 static int sp887x_readreg (struct sp887x_state* state, u16 reg)
77 {
78 	u8 b0 [] = { reg >> 8 , reg & 0xff };
79 	u8 b1 [2];
80 	int ret;
81 	struct i2c_msg msg[] = {{ .addr = state->config->demod_address, .flags = 0, .buf = b0, .len = 2 },
82 			 { .addr = state->config->demod_address, .flags = I2C_M_RD, .buf = b1, .len = 2 }};
83 
84 	if ((ret = i2c_transfer(state->i2c, msg, 2)) != 2) {
85 		printk("%s: readreg error (ret == %i)\n", __func__, ret);
86 		return -1;
87 	}
88 
89 	return (((b1[0] << 8) | b1[1]) & 0xfff);
90 }
91 
92 static void sp887x_microcontroller_stop (struct sp887x_state* state)
93 {
94 	dprintk("%s\n", __func__);
95 	sp887x_writereg(state, 0xf08, 0x000);
96 	sp887x_writereg(state, 0xf09, 0x000);
97 
98 	/* microcontroller STOP */
99 	sp887x_writereg(state, 0xf00, 0x000);
100 }
101 
102 static void sp887x_microcontroller_start (struct sp887x_state* state)
103 {
104 	dprintk("%s\n", __func__);
105 	sp887x_writereg(state, 0xf08, 0x000);
106 	sp887x_writereg(state, 0xf09, 0x000);
107 
108 	/* microcontroller START */
109 	sp887x_writereg(state, 0xf00, 0x001);
110 }
111 
112 static void sp887x_setup_agc (struct sp887x_state* state)
113 {
114 	/* setup AGC parameters */
115 	dprintk("%s\n", __func__);
116 	sp887x_writereg(state, 0x33c, 0x054);
117 	sp887x_writereg(state, 0x33b, 0x04c);
118 	sp887x_writereg(state, 0x328, 0x000);
119 	sp887x_writereg(state, 0x327, 0x005);
120 	sp887x_writereg(state, 0x326, 0x001);
121 	sp887x_writereg(state, 0x325, 0x001);
122 	sp887x_writereg(state, 0x324, 0x001);
123 	sp887x_writereg(state, 0x318, 0x050);
124 	sp887x_writereg(state, 0x317, 0x3fe);
125 	sp887x_writereg(state, 0x316, 0x001);
126 	sp887x_writereg(state, 0x313, 0x005);
127 	sp887x_writereg(state, 0x312, 0x002);
128 	sp887x_writereg(state, 0x306, 0x000);
129 	sp887x_writereg(state, 0x303, 0x000);
130 }
131 
132 #define BLOCKSIZE 30
133 #define FW_SIZE 0x4000
134 /*
135  *  load firmware and setup MPEG interface...
136  */
137 static int sp887x_initial_setup (struct dvb_frontend* fe, const struct firmware *fw)
138 {
139 	struct sp887x_state* state = fe->demodulator_priv;
140 	u8 buf [BLOCKSIZE + 2];
141 	int i;
142 	int fw_size = fw->size;
143 	const unsigned char *mem = fw->data + 10;
144 
145 	dprintk("%s\n", __func__);
146 
147 	/* ignore the first 10 bytes, then we expect 0x4000 bytes of firmware */
148 	if (fw_size < FW_SIZE + 10)
149 		return -ENODEV;
150 
151 	/* soft reset */
152 	sp887x_writereg(state, 0xf1a, 0x000);
153 
154 	sp887x_microcontroller_stop (state);
155 
156 	printk ("%s: firmware upload... ", __func__);
157 
158 	/* setup write pointer to -1 (end of memory) */
159 	/* bit 0x8000 in address is set to enable 13bit mode */
160 	sp887x_writereg(state, 0x8f08, 0x1fff);
161 
162 	/* dummy write (wrap around to start of memory) */
163 	sp887x_writereg(state, 0x8f0a, 0x0000);
164 
165 	for (i = 0; i < FW_SIZE; i += BLOCKSIZE) {
166 		int c = BLOCKSIZE;
167 		int err;
168 
169 		if (c > FW_SIZE - i)
170 			c = FW_SIZE - i;
171 
172 		/* bit 0x8000 in address is set to enable 13bit mode */
173 		/* bit 0x4000 enables multibyte read/write transfers */
174 		/* write register is 0xf0a */
175 		buf[0] = 0xcf;
176 		buf[1] = 0x0a;
177 
178 		memcpy(&buf[2], mem + i, c);
179 
180 		if ((err = i2c_writebytes (state, buf, c+2)) < 0) {
181 			printk ("failed.\n");
182 			printk ("%s: i2c error (err == %i)\n", __func__, err);
183 			return err;
184 		}
185 	}
186 
187 	/* don't write RS bytes between packets */
188 	sp887x_writereg(state, 0xc13, 0x001);
189 
190 	/* suppress clock if (!data_valid) */
191 	sp887x_writereg(state, 0xc14, 0x000);
192 
193 	/* setup MPEG interface... */
194 	sp887x_writereg(state, 0xc1a, 0x872);
195 	sp887x_writereg(state, 0xc1b, 0x001);
196 	sp887x_writereg(state, 0xc1c, 0x000); /* parallel mode (serial mode == 1) */
197 	sp887x_writereg(state, 0xc1a, 0x871);
198 
199 	/* ADC mode, 2 for MT8872, 3 for SP8870/SP8871 */
200 	sp887x_writereg(state, 0x301, 0x002);
201 
202 	sp887x_setup_agc(state);
203 
204 	/* bit 0x010: enable data valid signal */
205 	sp887x_writereg(state, 0xd00, 0x010);
206 	sp887x_writereg(state, 0x0d1, 0x000);
207 	return 0;
208 };
209 
210 static int configure_reg0xc05(struct dtv_frontend_properties *p, u16 *reg0xc05)
211 {
212 	int known_parameters = 1;
213 
214 	*reg0xc05 = 0x000;
215 
216 	switch (p->modulation) {
217 	case QPSK:
218 		break;
219 	case QAM_16:
220 		*reg0xc05 |= (1 << 10);
221 		break;
222 	case QAM_64:
223 		*reg0xc05 |= (2 << 10);
224 		break;
225 	case QAM_AUTO:
226 		known_parameters = 0;
227 		break;
228 	default:
229 		return -EINVAL;
230 	}
231 
232 	switch (p->hierarchy) {
233 	case HIERARCHY_NONE:
234 		break;
235 	case HIERARCHY_1:
236 		*reg0xc05 |= (1 << 7);
237 		break;
238 	case HIERARCHY_2:
239 		*reg0xc05 |= (2 << 7);
240 		break;
241 	case HIERARCHY_4:
242 		*reg0xc05 |= (3 << 7);
243 		break;
244 	case HIERARCHY_AUTO:
245 		known_parameters = 0;
246 		break;
247 	default:
248 		return -EINVAL;
249 	}
250 
251 	switch (p->code_rate_HP) {
252 	case FEC_1_2:
253 		break;
254 	case FEC_2_3:
255 		*reg0xc05 |= (1 << 3);
256 		break;
257 	case FEC_3_4:
258 		*reg0xc05 |= (2 << 3);
259 		break;
260 	case FEC_5_6:
261 		*reg0xc05 |= (3 << 3);
262 		break;
263 	case FEC_7_8:
264 		*reg0xc05 |= (4 << 3);
265 		break;
266 	case FEC_AUTO:
267 		known_parameters = 0;
268 		break;
269 	default:
270 		return -EINVAL;
271 	}
272 
273 	if (known_parameters)
274 		*reg0xc05 |= (2 << 1);	/* use specified parameters */
275 	else
276 		*reg0xc05 |= (1 << 1);	/* enable autoprobing */
277 
278 	return 0;
279 }
280 
281 /*
282  *  estimates division of two 24bit numbers,
283  *  derived from the ves1820/stv0299 driver code
284  */
285 static void divide (int n, int d, int *quotient_i, int *quotient_f)
286 {
287 	unsigned int q, r;
288 
289 	r = (n % d) << 8;
290 	q = (r / d);
291 
292 	if (quotient_i)
293 		*quotient_i = q;
294 
295 	if (quotient_f) {
296 		r = (r % d) << 8;
297 		q = (q << 8) | (r / d);
298 		r = (r % d) << 8;
299 		*quotient_f = (q << 8) | (r / d);
300 	}
301 }
302 
303 static void sp887x_correct_offsets (struct sp887x_state* state,
304 				    struct dtv_frontend_properties *p,
305 				    int actual_freq)
306 {
307 	static const u32 srate_correction [] = { 1879617, 4544878, 8098561 };
308 	int bw_index;
309 	int freq_offset = actual_freq - p->frequency;
310 	int sysclock = 61003; //[kHz]
311 	int ifreq = 36000000;
312 	int freq;
313 	int frequency_shift;
314 
315 	switch (p->bandwidth_hz) {
316 	default:
317 	case 8000000:
318 		bw_index = 0;
319 		break;
320 	case 7000000:
321 		bw_index = 1;
322 		break;
323 	case 6000000:
324 		bw_index = 2;
325 		break;
326 	}
327 
328 	if (p->inversion == INVERSION_ON)
329 		freq = ifreq - freq_offset;
330 	else
331 		freq = ifreq + freq_offset;
332 
333 	divide(freq / 333, sysclock, NULL, &frequency_shift);
334 
335 	if (p->inversion == INVERSION_ON)
336 		frequency_shift = -frequency_shift;
337 
338 	/* sample rate correction */
339 	sp887x_writereg(state, 0x319, srate_correction[bw_index] >> 12);
340 	sp887x_writereg(state, 0x31a, srate_correction[bw_index] & 0xfff);
341 
342 	/* carrier offset correction */
343 	sp887x_writereg(state, 0x309, frequency_shift >> 12);
344 	sp887x_writereg(state, 0x30a, frequency_shift & 0xfff);
345 }
346 
347 static int sp887x_setup_frontend_parameters(struct dvb_frontend *fe)
348 {
349 	struct dtv_frontend_properties *p = &fe->dtv_property_cache;
350 	struct sp887x_state* state = fe->demodulator_priv;
351 	unsigned actual_freq;
352 	int err;
353 	u16 val, reg0xc05;
354 
355 	if (p->bandwidth_hz != 8000000 &&
356 	    p->bandwidth_hz != 7000000 &&
357 	    p->bandwidth_hz != 6000000)
358 		return -EINVAL;
359 
360 	if ((err = configure_reg0xc05(p, &reg0xc05)))
361 		return err;
362 
363 	sp887x_microcontroller_stop(state);
364 
365 	/* setup the PLL */
366 	if (fe->ops.tuner_ops.set_params) {
367 		fe->ops.tuner_ops.set_params(fe);
368 		if (fe->ops.i2c_gate_ctrl) fe->ops.i2c_gate_ctrl(fe, 0);
369 	}
370 	if (fe->ops.tuner_ops.get_frequency) {
371 		fe->ops.tuner_ops.get_frequency(fe, &actual_freq);
372 		if (fe->ops.i2c_gate_ctrl) fe->ops.i2c_gate_ctrl(fe, 0);
373 	} else {
374 		actual_freq = p->frequency;
375 	}
376 
377 	/* read status reg in order to clear <pending irqs */
378 	sp887x_readreg(state, 0x200);
379 
380 	sp887x_correct_offsets(state, p, actual_freq);
381 
382 	/* filter for 6/7/8 Mhz channel */
383 	if (p->bandwidth_hz == 6000000)
384 		val = 2;
385 	else if (p->bandwidth_hz == 7000000)
386 		val = 1;
387 	else
388 		val = 0;
389 
390 	sp887x_writereg(state, 0x311, val);
391 
392 	/* scan order: 2k first = 0, 8k first = 1 */
393 	if (p->transmission_mode == TRANSMISSION_MODE_2K)
394 		sp887x_writereg(state, 0x338, 0x000);
395 	else
396 		sp887x_writereg(state, 0x338, 0x001);
397 
398 	sp887x_writereg(state, 0xc05, reg0xc05);
399 
400 	if (p->bandwidth_hz == 6000000)
401 		val = 2 << 3;
402 	else if (p->bandwidth_hz == 7000000)
403 		val = 3 << 3;
404 	else
405 		val = 0 << 3;
406 
407 	/* enable OFDM and SAW bits as lock indicators in sync register 0xf17,
408 	 * optimize algorithm for given bandwidth...
409 	 */
410 	sp887x_writereg(state, 0xf14, 0x160 | val);
411 	sp887x_writereg(state, 0xf15, 0x000);
412 
413 	sp887x_microcontroller_start(state);
414 	return 0;
415 }
416 
417 static int sp887x_read_status(struct dvb_frontend *fe, enum fe_status *status)
418 {
419 	struct sp887x_state* state = fe->demodulator_priv;
420 	u16 snr12 = sp887x_readreg(state, 0xf16);
421 	u16 sync0x200 = sp887x_readreg(state, 0x200);
422 	u16 sync0xf17 = sp887x_readreg(state, 0xf17);
423 
424 	*status = 0;
425 
426 	if (snr12 > 0x00f)
427 		*status |= FE_HAS_SIGNAL;
428 
429 	//if (sync0x200 & 0x004)
430 	//	*status |= FE_HAS_SYNC | FE_HAS_CARRIER;
431 
432 	//if (sync0x200 & 0x008)
433 	//	*status |= FE_HAS_VITERBI;
434 
435 	if ((sync0xf17 & 0x00f) == 0x002) {
436 		*status |= FE_HAS_LOCK;
437 		*status |= FE_HAS_VITERBI | FE_HAS_SYNC | FE_HAS_CARRIER;
438 	}
439 
440 	if (sync0x200 & 0x001) {	/* tuner adjustment requested...*/
441 		int steps = (sync0x200 >> 4) & 0x00f;
442 		if (steps & 0x008)
443 			steps = -steps;
444 		dprintk("sp887x: implement tuner adjustment (%+i steps)!!\n",
445 		       steps);
446 	}
447 
448 	return 0;
449 }
450 
451 static int sp887x_read_ber(struct dvb_frontend* fe, u32* ber)
452 {
453 	struct sp887x_state* state = fe->demodulator_priv;
454 
455 	*ber = (sp887x_readreg(state, 0xc08) & 0x3f) |
456 	       (sp887x_readreg(state, 0xc07) << 6);
457 	sp887x_writereg(state, 0xc08, 0x000);
458 	sp887x_writereg(state, 0xc07, 0x000);
459 	if (*ber >= 0x3fff0)
460 		*ber = ~0;
461 
462 	return 0;
463 }
464 
465 static int sp887x_read_signal_strength(struct dvb_frontend* fe, u16* strength)
466 {
467 	struct sp887x_state* state = fe->demodulator_priv;
468 
469 	u16 snr12 = sp887x_readreg(state, 0xf16);
470 	u32 signal = 3 * (snr12 << 4);
471 	*strength = (signal < 0xffff) ? signal : 0xffff;
472 
473 	return 0;
474 }
475 
476 static int sp887x_read_snr(struct dvb_frontend* fe, u16* snr)
477 {
478 	struct sp887x_state* state = fe->demodulator_priv;
479 
480 	u16 snr12 = sp887x_readreg(state, 0xf16);
481 	*snr = (snr12 << 4) | (snr12 >> 8);
482 
483 	return 0;
484 }
485 
486 static int sp887x_read_ucblocks(struct dvb_frontend* fe, u32* ucblocks)
487 {
488 	struct sp887x_state* state = fe->demodulator_priv;
489 
490 	*ucblocks = sp887x_readreg(state, 0xc0c);
491 	if (*ucblocks == 0xfff)
492 		*ucblocks = ~0;
493 
494 	return 0;
495 }
496 
497 static int sp887x_i2c_gate_ctrl(struct dvb_frontend* fe, int enable)
498 {
499 	struct sp887x_state* state = fe->demodulator_priv;
500 
501 	if (enable) {
502 		return sp887x_writereg(state, 0x206, 0x001);
503 	} else {
504 		return sp887x_writereg(state, 0x206, 0x000);
505 	}
506 }
507 
508 static int sp887x_sleep(struct dvb_frontend* fe)
509 {
510 	struct sp887x_state* state = fe->demodulator_priv;
511 
512 	/* tristate TS output and disable interface pins */
513 	sp887x_writereg(state, 0xc18, 0x000);
514 
515 	return 0;
516 }
517 
518 static int sp887x_init(struct dvb_frontend* fe)
519 {
520 	struct sp887x_state* state = fe->demodulator_priv;
521 	const struct firmware *fw = NULL;
522 	int ret;
523 
524 	if (!state->initialised) {
525 		/* request the firmware, this will block until someone uploads it */
526 		printk("sp887x: waiting for firmware upload (%s)...\n", SP887X_DEFAULT_FIRMWARE);
527 		ret = state->config->request_firmware(fe, &fw, SP887X_DEFAULT_FIRMWARE);
528 		if (ret) {
529 			printk("sp887x: no firmware upload (timeout or file not found?)\n");
530 			return ret;
531 		}
532 
533 		ret = sp887x_initial_setup(fe, fw);
534 		release_firmware(fw);
535 		if (ret) {
536 			printk("sp887x: writing firmware to device failed\n");
537 			return ret;
538 		}
539 		printk("sp887x: firmware upload complete\n");
540 		state->initialised = 1;
541 	}
542 
543 	/* enable TS output and interface pins */
544 	sp887x_writereg(state, 0xc18, 0x00d);
545 
546 	return 0;
547 }
548 
549 static int sp887x_get_tune_settings(struct dvb_frontend* fe, struct dvb_frontend_tune_settings* fesettings)
550 {
551 	fesettings->min_delay_ms = 350;
552 	fesettings->step_size = 166666*2;
553 	fesettings->max_drift = (166666*2)+1;
554 	return 0;
555 }
556 
557 static void sp887x_release(struct dvb_frontend* fe)
558 {
559 	struct sp887x_state* state = fe->demodulator_priv;
560 	kfree(state);
561 }
562 
563 static const struct dvb_frontend_ops sp887x_ops;
564 
565 struct dvb_frontend* sp887x_attach(const struct sp887x_config* config,
566 				   struct i2c_adapter* i2c)
567 {
568 	struct sp887x_state* state = NULL;
569 
570 	/* allocate memory for the internal state */
571 	state = kzalloc(sizeof(struct sp887x_state), GFP_KERNEL);
572 	if (state == NULL) goto error;
573 
574 	/* setup the state */
575 	state->config = config;
576 	state->i2c = i2c;
577 	state->initialised = 0;
578 
579 	/* check if the demod is there */
580 	if (sp887x_readreg(state, 0x0200) < 0) goto error;
581 
582 	/* create dvb_frontend */
583 	memcpy(&state->frontend.ops, &sp887x_ops, sizeof(struct dvb_frontend_ops));
584 	state->frontend.demodulator_priv = state;
585 	return &state->frontend;
586 
587 error:
588 	kfree(state);
589 	return NULL;
590 }
591 
592 static const struct dvb_frontend_ops sp887x_ops = {
593 	.delsys = { SYS_DVBT },
594 	.info = {
595 		.name = "Spase SP887x DVB-T",
596 		.frequency_min_hz =  50500 * kHz,
597 		.frequency_max_hz = 858000 * kHz,
598 		.frequency_stepsize_hz = 166666,
599 		.caps = FE_CAN_FEC_1_2 | FE_CAN_FEC_2_3 | FE_CAN_FEC_3_4 |
600 			FE_CAN_FEC_5_6 | FE_CAN_FEC_7_8 | FE_CAN_FEC_AUTO |
601 			FE_CAN_QPSK | FE_CAN_QAM_16 | FE_CAN_QAM_64 |
602 			FE_CAN_RECOVER
603 	},
604 
605 	.release = sp887x_release,
606 
607 	.init = sp887x_init,
608 	.sleep = sp887x_sleep,
609 	.i2c_gate_ctrl = sp887x_i2c_gate_ctrl,
610 
611 	.set_frontend = sp887x_setup_frontend_parameters,
612 	.get_tune_settings = sp887x_get_tune_settings,
613 
614 	.read_status = sp887x_read_status,
615 	.read_ber = sp887x_read_ber,
616 	.read_signal_strength = sp887x_read_signal_strength,
617 	.read_snr = sp887x_read_snr,
618 	.read_ucblocks = sp887x_read_ucblocks,
619 };
620 
621 module_param(debug, int, 0644);
622 MODULE_PARM_DESC(debug, "Turn on/off frontend debugging (default:off).");
623 
624 MODULE_DESCRIPTION("Spase sp887x DVB-T demodulator driver");
625 MODULE_LICENSE("GPL");
626 
627 EXPORT_SYMBOL(sp887x_attach);
628