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
25struct 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
34static int debug;
35#define dprintk(args...) \
36	do { \
37		if (debug) printk(KERN_DEBUG "sp887x: " args); \
38	} while (0)
39
40static 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
54static 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
76static 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
92static 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
102static 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
112static 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 */
137static 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
210static 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 */
285static 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
303static 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
347static 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
417static 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
451static 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
465static 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
476static 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
486static 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
497static 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
508static 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
518static 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
549static 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
557static void sp887x_release(struct dvb_frontend* fe)
558{
559	struct sp887x_state* state = fe->demodulator_priv;
560	kfree(state);
561}
562
563static const struct dvb_frontend_ops sp887x_ops;
564
565struct 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
587error:
588	kfree(state);
589	return NULL;
590}
591
592static 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
621module_param(debug, int, 0644);
622MODULE_PARM_DESC(debug, "Turn on/off frontend debugging (default:off).");
623
624MODULE_DESCRIPTION("Spase sp887x DVB-T demodulator driver");
625MODULE_LICENSE("GPL");
626
627EXPORT_SYMBOL_GPL(sp887x_attach);
628