1 // SPDX-License-Identifier: GPL-2.0-only
2 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
3 
4 #include <linux/i2c.h>
5 #include <linux/mutex.h>
6 #include <linux/module.h>
7 
8 #include "dibx000_common.h"
9 
10 static int debug;
11 module_param(debug, int, 0644);
12 MODULE_PARM_DESC(debug, "turn on debugging (default: 0)");
13 
14 #define dprintk(fmt, arg...) do {					\
15 	if (debug)							\
16 		printk(KERN_DEBUG pr_fmt("%s: " fmt),			\
17 		       __func__, ##arg);				\
18 } while (0)
19 
20 static int dibx000_write_word(struct dibx000_i2c_master *mst, u16 reg, u16 val)
21 {
22 	int ret;
23 
24 	if (mutex_lock_interruptible(&mst->i2c_buffer_lock) < 0) {
25 		dprintk("could not acquire lock\n");
26 		return -EINVAL;
27 	}
28 
29 	mst->i2c_write_buffer[0] = (reg >> 8) & 0xff;
30 	mst->i2c_write_buffer[1] = reg & 0xff;
31 	mst->i2c_write_buffer[2] = (val >> 8) & 0xff;
32 	mst->i2c_write_buffer[3] = val & 0xff;
33 
34 	memset(mst->msg, 0, sizeof(struct i2c_msg));
35 	mst->msg[0].addr = mst->i2c_addr;
36 	mst->msg[0].flags = 0;
37 	mst->msg[0].buf = mst->i2c_write_buffer;
38 	mst->msg[0].len = 4;
39 
40 	ret = i2c_transfer(mst->i2c_adap, mst->msg, 1) != 1 ? -EREMOTEIO : 0;
41 	mutex_unlock(&mst->i2c_buffer_lock);
42 
43 	return ret;
44 }
45 
46 static u16 dibx000_read_word(struct dibx000_i2c_master *mst, u16 reg)
47 {
48 	u16 ret;
49 
50 	if (mutex_lock_interruptible(&mst->i2c_buffer_lock) < 0) {
51 		dprintk("could not acquire lock\n");
52 		return 0;
53 	}
54 
55 	mst->i2c_write_buffer[0] = reg >> 8;
56 	mst->i2c_write_buffer[1] = reg & 0xff;
57 
58 	memset(mst->msg, 0, 2 * sizeof(struct i2c_msg));
59 	mst->msg[0].addr = mst->i2c_addr;
60 	mst->msg[0].flags = 0;
61 	mst->msg[0].buf = mst->i2c_write_buffer;
62 	mst->msg[0].len = 2;
63 	mst->msg[1].addr = mst->i2c_addr;
64 	mst->msg[1].flags = I2C_M_RD;
65 	mst->msg[1].buf = mst->i2c_read_buffer;
66 	mst->msg[1].len = 2;
67 
68 	if (i2c_transfer(mst->i2c_adap, mst->msg, 2) != 2)
69 		dprintk("i2c read error on %d\n", reg);
70 
71 	ret = (mst->i2c_read_buffer[0] << 8) | mst->i2c_read_buffer[1];
72 	mutex_unlock(&mst->i2c_buffer_lock);
73 
74 	return ret;
75 }
76 
77 static int dibx000_is_i2c_done(struct dibx000_i2c_master *mst)
78 {
79 	int i = 100;
80 	u16 status;
81 
82 	while (((status = dibx000_read_word(mst, mst->base_reg + 2)) & 0x0100) == 0 && --i > 0)
83 		;
84 
85 	/* i2c timed out */
86 	if (i == 0)
87 		return -EREMOTEIO;
88 
89 	/* no acknowledge */
90 	if ((status & 0x0080) == 0)
91 		return -EREMOTEIO;
92 
93 	return 0;
94 }
95 
96 static int dibx000_master_i2c_write(struct dibx000_i2c_master *mst, struct i2c_msg *msg, u8 stop)
97 {
98 	u16 data;
99 	u16 da;
100 	u16 i;
101 	u16 txlen = msg->len, len;
102 	const u8 *b = msg->buf;
103 
104 	while (txlen) {
105 		dibx000_read_word(mst, mst->base_reg + 2);
106 
107 		len = txlen > 8 ? 8 : txlen;
108 		for (i = 0; i < len; i += 2) {
109 			data = *b++ << 8;
110 			if (i+1 < len)
111 				data |= *b++;
112 			dibx000_write_word(mst, mst->base_reg, data);
113 		}
114 		da = (((u8) (msg->addr))  << 9) |
115 			(1           << 8) |
116 			(1           << 7) |
117 			(0           << 6) |
118 			(0           << 5) |
119 			((len & 0x7) << 2) |
120 			(0           << 1) |
121 			(0           << 0);
122 
123 		if (txlen == msg->len)
124 			da |= 1 << 5; /* start */
125 
126 		if (txlen-len == 0 && stop)
127 			da |= 1 << 6; /* stop */
128 
129 		dibx000_write_word(mst, mst->base_reg+1, da);
130 
131 		if (dibx000_is_i2c_done(mst) != 0)
132 			return -EREMOTEIO;
133 		txlen -= len;
134 	}
135 
136 	return 0;
137 }
138 
139 static int dibx000_master_i2c_read(struct dibx000_i2c_master *mst, struct i2c_msg *msg)
140 {
141 	u16 da;
142 	u8 *b = msg->buf;
143 	u16 rxlen = msg->len, len;
144 
145 	while (rxlen) {
146 		len = rxlen > 8 ? 8 : rxlen;
147 		da = (((u8) (msg->addr)) << 9) |
148 			(1           << 8) |
149 			(1           << 7) |
150 			(0           << 6) |
151 			(0           << 5) |
152 			((len & 0x7) << 2) |
153 			(1           << 1) |
154 			(0           << 0);
155 
156 		if (rxlen == msg->len)
157 			da |= 1 << 5; /* start */
158 
159 		if (rxlen-len == 0)
160 			da |= 1 << 6; /* stop */
161 		dibx000_write_word(mst, mst->base_reg+1, da);
162 
163 		if (dibx000_is_i2c_done(mst) != 0)
164 			return -EREMOTEIO;
165 
166 		rxlen -= len;
167 
168 		while (len) {
169 			da = dibx000_read_word(mst, mst->base_reg);
170 			*b++ = (da >> 8) & 0xff;
171 			len--;
172 			if (len >= 1) {
173 				*b++ =  da   & 0xff;
174 				len--;
175 			}
176 		}
177 	}
178 
179 	return 0;
180 }
181 
182 int dibx000_i2c_set_speed(struct i2c_adapter *i2c_adap, u16 speed)
183 {
184 	struct dibx000_i2c_master *mst = i2c_get_adapdata(i2c_adap);
185 
186 	if (mst->device_rev < DIB7000MC && speed < 235)
187 		speed = 235;
188 	return dibx000_write_word(mst, mst->base_reg + 3, (u16)(60000 / speed));
189 
190 }
191 EXPORT_SYMBOL(dibx000_i2c_set_speed);
192 
193 static u32 dibx000_i2c_func(struct i2c_adapter *adapter)
194 {
195 	return I2C_FUNC_I2C;
196 }
197 
198 static int dibx000_i2c_select_interface(struct dibx000_i2c_master *mst,
199 					enum dibx000_i2c_interface intf)
200 {
201 	if (mst->device_rev > DIB3000MC && mst->selected_interface != intf) {
202 		dprintk("selecting interface: %d\n", intf);
203 		mst->selected_interface = intf;
204 		return dibx000_write_word(mst, mst->base_reg + 4, intf);
205 	}
206 	return 0;
207 }
208 
209 static int dibx000_i2c_master_xfer_gpio12(struct i2c_adapter *i2c_adap, struct i2c_msg msg[], int num)
210 {
211 	struct dibx000_i2c_master *mst = i2c_get_adapdata(i2c_adap);
212 	int msg_index;
213 	int ret = 0;
214 
215 	dibx000_i2c_select_interface(mst, DIBX000_I2C_INTERFACE_GPIO_1_2);
216 	for (msg_index = 0; msg_index < num; msg_index++) {
217 		if (msg[msg_index].flags & I2C_M_RD) {
218 			ret = dibx000_master_i2c_read(mst, &msg[msg_index]);
219 			if (ret != 0)
220 				return 0;
221 		} else {
222 			ret = dibx000_master_i2c_write(mst, &msg[msg_index], 1);
223 			if (ret != 0)
224 				return 0;
225 		}
226 	}
227 
228 	return num;
229 }
230 
231 static int dibx000_i2c_master_xfer_gpio34(struct i2c_adapter *i2c_adap, struct i2c_msg msg[], int num)
232 {
233 	struct dibx000_i2c_master *mst = i2c_get_adapdata(i2c_adap);
234 	int msg_index;
235 	int ret = 0;
236 
237 	dibx000_i2c_select_interface(mst, DIBX000_I2C_INTERFACE_GPIO_3_4);
238 	for (msg_index = 0; msg_index < num; msg_index++) {
239 		if (msg[msg_index].flags & I2C_M_RD) {
240 			ret = dibx000_master_i2c_read(mst, &msg[msg_index]);
241 			if (ret != 0)
242 				return 0;
243 		} else {
244 			ret = dibx000_master_i2c_write(mst, &msg[msg_index], 1);
245 			if (ret != 0)
246 				return 0;
247 		}
248 	}
249 
250 	return num;
251 }
252 
253 static struct i2c_algorithm dibx000_i2c_master_gpio12_xfer_algo = {
254 	.master_xfer = dibx000_i2c_master_xfer_gpio12,
255 	.functionality = dibx000_i2c_func,
256 };
257 
258 static struct i2c_algorithm dibx000_i2c_master_gpio34_xfer_algo = {
259 	.master_xfer = dibx000_i2c_master_xfer_gpio34,
260 	.functionality = dibx000_i2c_func,
261 };
262 
263 static int dibx000_i2c_gate_ctrl(struct dibx000_i2c_master *mst, u8 tx[4],
264 				 u8 addr, int onoff)
265 {
266 	u16 val;
267 
268 
269 	if (onoff)
270 		val = addr << 8;	// bit 7 = use master or not, if 0, the gate is open
271 	else
272 		val = 1 << 7;
273 
274 	if (mst->device_rev > DIB7000)
275 		val <<= 1;
276 
277 	tx[0] = (((mst->base_reg + 1) >> 8) & 0xff);
278 	tx[1] = ((mst->base_reg + 1) & 0xff);
279 	tx[2] = val >> 8;
280 	tx[3] = val & 0xff;
281 
282 	return 0;
283 }
284 
285 static int dibx000_i2c_gated_gpio67_xfer(struct i2c_adapter *i2c_adap,
286 					struct i2c_msg msg[], int num)
287 {
288 	struct dibx000_i2c_master *mst = i2c_get_adapdata(i2c_adap);
289 	int ret;
290 
291 	if (num > 32) {
292 		dprintk("%s: too much I2C message to be transmitted (%i). Maximum is 32",
293 			__func__, num);
294 		return -ENOMEM;
295 	}
296 
297 	dibx000_i2c_select_interface(mst, DIBX000_I2C_INTERFACE_GPIO_6_7);
298 
299 	if (mutex_lock_interruptible(&mst->i2c_buffer_lock) < 0) {
300 		dprintk("could not acquire lock\n");
301 		return -EINVAL;
302 	}
303 
304 	memset(mst->msg, 0, sizeof(struct i2c_msg) * (2 + num));
305 
306 	/* open the gate */
307 	dibx000_i2c_gate_ctrl(mst, &mst->i2c_write_buffer[0], msg[0].addr, 1);
308 	mst->msg[0].addr = mst->i2c_addr;
309 	mst->msg[0].buf = &mst->i2c_write_buffer[0];
310 	mst->msg[0].len = 4;
311 
312 	memcpy(&mst->msg[1], msg, sizeof(struct i2c_msg) * num);
313 
314 	/* close the gate */
315 	dibx000_i2c_gate_ctrl(mst, &mst->i2c_write_buffer[4], 0, 0);
316 	mst->msg[num + 1].addr = mst->i2c_addr;
317 	mst->msg[num + 1].buf = &mst->i2c_write_buffer[4];
318 	mst->msg[num + 1].len = 4;
319 
320 	ret = (i2c_transfer(mst->i2c_adap, mst->msg, 2 + num) == 2 + num ?
321 			num : -EIO);
322 
323 	mutex_unlock(&mst->i2c_buffer_lock);
324 	return ret;
325 }
326 
327 static struct i2c_algorithm dibx000_i2c_gated_gpio67_algo = {
328 	.master_xfer = dibx000_i2c_gated_gpio67_xfer,
329 	.functionality = dibx000_i2c_func,
330 };
331 
332 static int dibx000_i2c_gated_tuner_xfer(struct i2c_adapter *i2c_adap,
333 					struct i2c_msg msg[], int num)
334 {
335 	struct dibx000_i2c_master *mst = i2c_get_adapdata(i2c_adap);
336 	int ret;
337 
338 	if (num > 32) {
339 		dprintk("%s: too much I2C message to be transmitted (%i). Maximum is 32",
340 			__func__, num);
341 		return -ENOMEM;
342 	}
343 
344 	dibx000_i2c_select_interface(mst, DIBX000_I2C_INTERFACE_TUNER);
345 
346 	if (mutex_lock_interruptible(&mst->i2c_buffer_lock) < 0) {
347 		dprintk("could not acquire lock\n");
348 		return -EINVAL;
349 	}
350 	memset(mst->msg, 0, sizeof(struct i2c_msg) * (2 + num));
351 
352 	/* open the gate */
353 	dibx000_i2c_gate_ctrl(mst, &mst->i2c_write_buffer[0], msg[0].addr, 1);
354 	mst->msg[0].addr = mst->i2c_addr;
355 	mst->msg[0].buf = &mst->i2c_write_buffer[0];
356 	mst->msg[0].len = 4;
357 
358 	memcpy(&mst->msg[1], msg, sizeof(struct i2c_msg) * num);
359 
360 	/* close the gate */
361 	dibx000_i2c_gate_ctrl(mst, &mst->i2c_write_buffer[4], 0, 0);
362 	mst->msg[num + 1].addr = mst->i2c_addr;
363 	mst->msg[num + 1].buf = &mst->i2c_write_buffer[4];
364 	mst->msg[num + 1].len = 4;
365 
366 	ret = (i2c_transfer(mst->i2c_adap, mst->msg, 2 + num) == 2 + num ?
367 			num : -EIO);
368 	mutex_unlock(&mst->i2c_buffer_lock);
369 	return ret;
370 }
371 
372 static struct i2c_algorithm dibx000_i2c_gated_tuner_algo = {
373 	.master_xfer = dibx000_i2c_gated_tuner_xfer,
374 	.functionality = dibx000_i2c_func,
375 };
376 
377 struct i2c_adapter *dibx000_get_i2c_adapter(struct dibx000_i2c_master *mst,
378 						enum dibx000_i2c_interface intf,
379 						int gating)
380 {
381 	struct i2c_adapter *i2c = NULL;
382 
383 	switch (intf) {
384 	case DIBX000_I2C_INTERFACE_TUNER:
385 		if (gating)
386 			i2c = &mst->gated_tuner_i2c_adap;
387 		break;
388 	case DIBX000_I2C_INTERFACE_GPIO_1_2:
389 		if (!gating)
390 			i2c = &mst->master_i2c_adap_gpio12;
391 		break;
392 	case DIBX000_I2C_INTERFACE_GPIO_3_4:
393 		if (!gating)
394 			i2c = &mst->master_i2c_adap_gpio34;
395 		break;
396 	case DIBX000_I2C_INTERFACE_GPIO_6_7:
397 		if (gating)
398 			i2c = &mst->master_i2c_adap_gpio67;
399 		break;
400 	default:
401 		pr_err("incorrect I2C interface selected\n");
402 		break;
403 	}
404 
405 	return i2c;
406 }
407 
408 EXPORT_SYMBOL(dibx000_get_i2c_adapter);
409 
410 void dibx000_reset_i2c_master(struct dibx000_i2c_master *mst)
411 {
412 	/* initialize the i2c-master by closing the gate */
413 	u8 tx[4];
414 	struct i2c_msg m = {.addr = mst->i2c_addr,.buf = tx,.len = 4 };
415 
416 	dibx000_i2c_gate_ctrl(mst, tx, 0, 0);
417 	i2c_transfer(mst->i2c_adap, &m, 1);
418 	mst->selected_interface = 0xff;	// the first time force a select of the I2C
419 	dibx000_i2c_select_interface(mst, DIBX000_I2C_INTERFACE_TUNER);
420 }
421 
422 EXPORT_SYMBOL(dibx000_reset_i2c_master);
423 
424 static int i2c_adapter_init(struct i2c_adapter *i2c_adap,
425 				struct i2c_algorithm *algo, const char *name,
426 				struct dibx000_i2c_master *mst)
427 {
428 	strscpy(i2c_adap->name, name, sizeof(i2c_adap->name));
429 	i2c_adap->algo = algo;
430 	i2c_adap->algo_data = NULL;
431 	i2c_set_adapdata(i2c_adap, mst);
432 	if (i2c_add_adapter(i2c_adap) < 0)
433 		return -ENODEV;
434 	return 0;
435 }
436 
437 int dibx000_init_i2c_master(struct dibx000_i2c_master *mst, u16 device_rev,
438 				struct i2c_adapter *i2c_adap, u8 i2c_addr)
439 {
440 	int ret;
441 
442 	mutex_init(&mst->i2c_buffer_lock);
443 	if (mutex_lock_interruptible(&mst->i2c_buffer_lock) < 0) {
444 		dprintk("could not acquire lock\n");
445 		return -EINVAL;
446 	}
447 	memset(mst->msg, 0, sizeof(struct i2c_msg));
448 	mst->msg[0].addr = i2c_addr >> 1;
449 	mst->msg[0].flags = 0;
450 	mst->msg[0].buf = mst->i2c_write_buffer;
451 	mst->msg[0].len = 4;
452 
453 	mst->device_rev = device_rev;
454 	mst->i2c_adap = i2c_adap;
455 	mst->i2c_addr = i2c_addr >> 1;
456 
457 	if (device_rev == DIB7000P || device_rev == DIB8000)
458 		mst->base_reg = 1024;
459 	else
460 		mst->base_reg = 768;
461 
462 	mst->gated_tuner_i2c_adap.dev.parent = mst->i2c_adap->dev.parent;
463 	if (i2c_adapter_init
464 			(&mst->gated_tuner_i2c_adap, &dibx000_i2c_gated_tuner_algo,
465 			 "DiBX000 tuner I2C bus", mst) != 0)
466 		pr_err("could not initialize the tuner i2c_adapter\n");
467 
468 	mst->master_i2c_adap_gpio12.dev.parent = mst->i2c_adap->dev.parent;
469 	if (i2c_adapter_init
470 			(&mst->master_i2c_adap_gpio12, &dibx000_i2c_master_gpio12_xfer_algo,
471 			 "DiBX000 master GPIO12 I2C bus", mst) != 0)
472 		pr_err("could not initialize the master i2c_adapter\n");
473 
474 	mst->master_i2c_adap_gpio34.dev.parent = mst->i2c_adap->dev.parent;
475 	if (i2c_adapter_init
476 			(&mst->master_i2c_adap_gpio34, &dibx000_i2c_master_gpio34_xfer_algo,
477 			 "DiBX000 master GPIO34 I2C bus", mst) != 0)
478 		pr_err("could not initialize the master i2c_adapter\n");
479 
480 	mst->master_i2c_adap_gpio67.dev.parent = mst->i2c_adap->dev.parent;
481 	if (i2c_adapter_init
482 			(&mst->master_i2c_adap_gpio67, &dibx000_i2c_gated_gpio67_algo,
483 			 "DiBX000 master GPIO67 I2C bus", mst) != 0)
484 		pr_err("could not initialize the master i2c_adapter\n");
485 
486 	/* initialize the i2c-master by closing the gate */
487 	dibx000_i2c_gate_ctrl(mst, mst->i2c_write_buffer, 0, 0);
488 
489 	ret = (i2c_transfer(i2c_adap, mst->msg, 1) == 1);
490 	mutex_unlock(&mst->i2c_buffer_lock);
491 
492 	return ret;
493 }
494 
495 EXPORT_SYMBOL(dibx000_init_i2c_master);
496 
497 void dibx000_exit_i2c_master(struct dibx000_i2c_master *mst)
498 {
499 	i2c_del_adapter(&mst->gated_tuner_i2c_adap);
500 	i2c_del_adapter(&mst->master_i2c_adap_gpio12);
501 	i2c_del_adapter(&mst->master_i2c_adap_gpio34);
502 	i2c_del_adapter(&mst->master_i2c_adap_gpio67);
503 }
504 EXPORT_SYMBOL(dibx000_exit_i2c_master);
505 
506 MODULE_AUTHOR("Patrick Boettcher <patrick.boettcher@posteo.de>");
507 MODULE_DESCRIPTION("Common function the DiBcom demodulator family");
508 MODULE_LICENSE("GPL");
509