1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2018 MediaTek Inc.
4  *
5  * Author: Sean Wang <sean.wang@mediatek.com>
6  *
7  */
8 
9 #include <linux/device.h>
10 #include <linux/err.h>
11 #include <linux/gpio/driver.h>
12 #include <linux/platform_device.h>
13 #include <linux/io.h>
14 #include <linux/of_irq.h>
15 
16 #include "mtk-eint.h"
17 #include "pinctrl-mtk-common-v2.h"
18 
19 /**
20  * struct mtk_drive_desc - the structure that holds the information
21  *			    of the driving current
22  * @min:	the minimum current of this group
23  * @max:	the maximum current of this group
24  * @step:	the step current of this group
25  * @scal:	the weight factor
26  *
27  * formula: output = ((input) / step - 1) * scal
28  */
29 struct mtk_drive_desc {
30 	u8 min;
31 	u8 max;
32 	u8 step;
33 	u8 scal;
34 };
35 
36 /* The groups of drive strength */
37 static const struct mtk_drive_desc mtk_drive[] = {
38 	[DRV_GRP0] = { 4, 16, 4, 1 },
39 	[DRV_GRP1] = { 4, 16, 4, 2 },
40 	[DRV_GRP2] = { 2, 8, 2, 1 },
41 	[DRV_GRP3] = { 2, 8, 2, 2 },
42 	[DRV_GRP4] = { 2, 16, 2, 1 },
43 };
44 
45 static void mtk_w32(struct mtk_pinctrl *pctl, u8 i, u32 reg, u32 val)
46 {
47 	writel_relaxed(val, pctl->base[i] + reg);
48 }
49 
50 static u32 mtk_r32(struct mtk_pinctrl *pctl, u8 i, u32 reg)
51 {
52 	return readl_relaxed(pctl->base[i] + reg);
53 }
54 
55 void mtk_rmw(struct mtk_pinctrl *pctl, u8 i, u32 reg, u32 mask, u32 set)
56 {
57 	u32 val;
58 
59 	val = mtk_r32(pctl, i, reg);
60 	val &= ~mask;
61 	val |= set;
62 	mtk_w32(pctl, i, reg, val);
63 }
64 
65 static int mtk_hw_pin_field_lookup(struct mtk_pinctrl *hw,
66 				   const struct mtk_pin_desc *desc,
67 				   int field, struct mtk_pin_field *pfd)
68 {
69 	const struct mtk_pin_field_calc *c, *e;
70 	const struct mtk_pin_reg_calc *rc;
71 	u32 bits;
72 
73 	if (hw->soc->reg_cal && hw->soc->reg_cal[field].range) {
74 		rc = &hw->soc->reg_cal[field];
75 	} else {
76 		dev_dbg(hw->dev,
77 			"Not support field %d for pin %d (%s)\n",
78 			field, desc->number, desc->name);
79 		return -ENOTSUPP;
80 	}
81 
82 	c = rc->range;
83 	e = c + rc->nranges;
84 
85 	while (c < e) {
86 		if (desc->number >= c->s_pin && desc->number <= c->e_pin)
87 			break;
88 		c++;
89 	}
90 
91 	if (c >= e) {
92 		dev_dbg(hw->dev, "Not support field %d for pin = %d (%s)\n",
93 			field, desc->number, desc->name);
94 		return -ENOTSUPP;
95 	}
96 
97 	if (c->i_base > hw->nbase - 1) {
98 		dev_err(hw->dev,
99 			"Invalid base for field %d for pin = %d (%s)\n",
100 			field, desc->number, desc->name);
101 		return -EINVAL;
102 	}
103 
104 	/* Calculated bits as the overall offset the pin is located at,
105 	 * if c->fixed is held, that determines the all the pins in the
106 	 * range use the same field with the s_pin.
107 	 */
108 	bits = c->fixed ? c->s_bit : c->s_bit +
109 	       (desc->number - c->s_pin) * (c->x_bits);
110 
111 	/* Fill pfd from bits. For example 32-bit register applied is assumed
112 	 * when c->sz_reg is equal to 32.
113 	 */
114 	pfd->index = c->i_base;
115 	pfd->offset = c->s_addr + c->x_addrs * (bits / c->sz_reg);
116 	pfd->bitpos = bits % c->sz_reg;
117 	pfd->mask = (1 << c->x_bits) - 1;
118 
119 	/* pfd->next is used for indicating that bit wrapping-around happens
120 	 * which requires the manipulation for bit 0 starting in the next
121 	 * register to form the complete field read/write.
122 	 */
123 	pfd->next = pfd->bitpos + c->x_bits > c->sz_reg ? c->x_addrs : 0;
124 
125 	return 0;
126 }
127 
128 static int mtk_hw_pin_field_get(struct mtk_pinctrl *hw,
129 				const struct mtk_pin_desc *desc,
130 				int field, struct mtk_pin_field *pfd)
131 {
132 	if (field < 0 || field >= PINCTRL_PIN_REG_MAX) {
133 		dev_err(hw->dev, "Invalid Field %d\n", field);
134 		return -EINVAL;
135 	}
136 
137 	return mtk_hw_pin_field_lookup(hw, desc, field, pfd);
138 }
139 
140 static void mtk_hw_bits_part(struct mtk_pin_field *pf, int *h, int *l)
141 {
142 	*l = 32 - pf->bitpos;
143 	*h = get_count_order(pf->mask) - *l;
144 }
145 
146 static void mtk_hw_write_cross_field(struct mtk_pinctrl *hw,
147 				     struct mtk_pin_field *pf, int value)
148 {
149 	int nbits_l, nbits_h;
150 
151 	mtk_hw_bits_part(pf, &nbits_h, &nbits_l);
152 
153 	mtk_rmw(hw, pf->index, pf->offset, pf->mask << pf->bitpos,
154 		(value & pf->mask) << pf->bitpos);
155 
156 	mtk_rmw(hw, pf->index, pf->offset + pf->next, BIT(nbits_h) - 1,
157 		(value & pf->mask) >> nbits_l);
158 }
159 
160 static void mtk_hw_read_cross_field(struct mtk_pinctrl *hw,
161 				    struct mtk_pin_field *pf, int *value)
162 {
163 	int nbits_l, nbits_h, h, l;
164 
165 	mtk_hw_bits_part(pf, &nbits_h, &nbits_l);
166 
167 	l  = (mtk_r32(hw, pf->index, pf->offset)
168 	      >> pf->bitpos) & (BIT(nbits_l) - 1);
169 	h  = (mtk_r32(hw, pf->index, pf->offset + pf->next))
170 	      & (BIT(nbits_h) - 1);
171 
172 	*value = (h << nbits_l) | l;
173 }
174 
175 int mtk_hw_set_value(struct mtk_pinctrl *hw, const struct mtk_pin_desc *desc,
176 		     int field, int value)
177 {
178 	struct mtk_pin_field pf;
179 	int err;
180 
181 	err = mtk_hw_pin_field_get(hw, desc, field, &pf);
182 	if (err)
183 		return err;
184 
185 	if (!pf.next)
186 		mtk_rmw(hw, pf.index, pf.offset, pf.mask << pf.bitpos,
187 			(value & pf.mask) << pf.bitpos);
188 	else
189 		mtk_hw_write_cross_field(hw, &pf, value);
190 
191 	return 0;
192 }
193 
194 int mtk_hw_get_value(struct mtk_pinctrl *hw, const struct mtk_pin_desc *desc,
195 		     int field, int *value)
196 {
197 	struct mtk_pin_field pf;
198 	int err;
199 
200 	err = mtk_hw_pin_field_get(hw, desc, field, &pf);
201 	if (err)
202 		return err;
203 
204 	if (!pf.next)
205 		*value = (mtk_r32(hw, pf.index, pf.offset)
206 			  >> pf.bitpos) & pf.mask;
207 	else
208 		mtk_hw_read_cross_field(hw, &pf, value);
209 
210 	return 0;
211 }
212 
213 static int mtk_xt_find_eint_num(struct mtk_pinctrl *hw, unsigned long eint_n)
214 {
215 	const struct mtk_pin_desc *desc;
216 	int i = 0;
217 
218 	desc = (const struct mtk_pin_desc *)hw->soc->pins;
219 
220 	while (i < hw->soc->npins) {
221 		if (desc[i].eint.eint_n == eint_n)
222 			return desc[i].number;
223 		i++;
224 	}
225 
226 	return EINT_NA;
227 }
228 
229 static int mtk_xt_get_gpio_n(void *data, unsigned long eint_n,
230 			     unsigned int *gpio_n,
231 			     struct gpio_chip **gpio_chip)
232 {
233 	struct mtk_pinctrl *hw = (struct mtk_pinctrl *)data;
234 	const struct mtk_pin_desc *desc;
235 
236 	desc = (const struct mtk_pin_desc *)hw->soc->pins;
237 	*gpio_chip = &hw->chip;
238 
239 	/* Be greedy to guess first gpio_n is equal to eint_n */
240 	if (desc[eint_n].eint.eint_n == eint_n)
241 		*gpio_n = eint_n;
242 	else
243 		*gpio_n = mtk_xt_find_eint_num(hw, eint_n);
244 
245 	return *gpio_n == EINT_NA ? -EINVAL : 0;
246 }
247 
248 static int mtk_xt_get_gpio_state(void *data, unsigned long eint_n)
249 {
250 	struct mtk_pinctrl *hw = (struct mtk_pinctrl *)data;
251 	const struct mtk_pin_desc *desc;
252 	struct gpio_chip *gpio_chip;
253 	unsigned int gpio_n;
254 	int value, err;
255 
256 	err = mtk_xt_get_gpio_n(hw, eint_n, &gpio_n, &gpio_chip);
257 	if (err)
258 		return err;
259 
260 	desc = (const struct mtk_pin_desc *)&hw->soc->pins[gpio_n];
261 
262 	err = mtk_hw_get_value(hw, desc, PINCTRL_PIN_REG_DI, &value);
263 	if (err)
264 		return err;
265 
266 	return !!value;
267 }
268 
269 static int mtk_xt_set_gpio_as_eint(void *data, unsigned long eint_n)
270 {
271 	struct mtk_pinctrl *hw = (struct mtk_pinctrl *)data;
272 	const struct mtk_pin_desc *desc;
273 	struct gpio_chip *gpio_chip;
274 	unsigned int gpio_n;
275 	int err;
276 
277 	err = mtk_xt_get_gpio_n(hw, eint_n, &gpio_n, &gpio_chip);
278 	if (err)
279 		return err;
280 
281 	desc = (const struct mtk_pin_desc *)&hw->soc->pins[gpio_n];
282 
283 	err = mtk_hw_set_value(hw, desc, PINCTRL_PIN_REG_MODE,
284 			       desc->eint.eint_m);
285 	if (err)
286 		return err;
287 
288 	err = mtk_hw_set_value(hw, desc, PINCTRL_PIN_REG_DIR, MTK_INPUT);
289 	if (err)
290 		return err;
291 
292 	err = mtk_hw_set_value(hw, desc, PINCTRL_PIN_REG_SMT, MTK_ENABLE);
293 	/* SMT is supposed to be supported by every real GPIO and doesn't
294 	 * support virtual GPIOs, so the extra condition err != -ENOTSUPP
295 	 * is just for adding EINT support to these virtual GPIOs. It should
296 	 * add an extra flag in the pin descriptor when more pins with
297 	 * distinctive characteristic come out.
298 	 */
299 	if (err && err != -ENOTSUPP)
300 		return err;
301 
302 	return 0;
303 }
304 
305 static const struct mtk_eint_xt mtk_eint_xt = {
306 	.get_gpio_n = mtk_xt_get_gpio_n,
307 	.get_gpio_state = mtk_xt_get_gpio_state,
308 	.set_gpio_as_eint = mtk_xt_set_gpio_as_eint,
309 };
310 
311 int mtk_build_eint(struct mtk_pinctrl *hw, struct platform_device *pdev)
312 {
313 	struct device_node *np = pdev->dev.of_node;
314 	struct resource *res;
315 
316 	if (!IS_ENABLED(CONFIG_EINT_MTK))
317 		return 0;
318 
319 	if (!of_property_read_bool(np, "interrupt-controller"))
320 		return -ENODEV;
321 
322 	hw->eint = devm_kzalloc(hw->dev, sizeof(*hw->eint), GFP_KERNEL);
323 	if (!hw->eint)
324 		return -ENOMEM;
325 
326 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "eint");
327 	if (!res) {
328 		dev_err(&pdev->dev, "Unable to get eint resource\n");
329 		return -ENODEV;
330 	}
331 
332 	hw->eint->base = devm_ioremap_resource(&pdev->dev, res);
333 	if (IS_ERR(hw->eint->base))
334 		return PTR_ERR(hw->eint->base);
335 
336 	hw->eint->irq = irq_of_parse_and_map(np, 0);
337 	if (!hw->eint->irq)
338 		return -EINVAL;
339 
340 	if (!hw->soc->eint_hw)
341 		return -ENODEV;
342 
343 	hw->eint->dev = &pdev->dev;
344 	hw->eint->hw = hw->soc->eint_hw;
345 	hw->eint->pctl = hw;
346 	hw->eint->gpio_xlate = &mtk_eint_xt;
347 
348 	return mtk_eint_do_init(hw->eint);
349 }
350 
351 /* Revision 0 */
352 int mtk_pinconf_bias_disable_set(struct mtk_pinctrl *hw,
353 				 const struct mtk_pin_desc *desc)
354 {
355 	int err;
356 
357 	err = mtk_hw_set_value(hw, desc, PINCTRL_PIN_REG_PU,
358 			       MTK_DISABLE);
359 	if (err)
360 		return err;
361 
362 	err = mtk_hw_set_value(hw, desc, PINCTRL_PIN_REG_PD,
363 			       MTK_DISABLE);
364 	if (err)
365 		return err;
366 
367 	return 0;
368 }
369 
370 int mtk_pinconf_bias_disable_get(struct mtk_pinctrl *hw,
371 				 const struct mtk_pin_desc *desc, int *res)
372 {
373 	int v, v2;
374 	int err;
375 
376 	err = mtk_hw_get_value(hw, desc, PINCTRL_PIN_REG_PU, &v);
377 	if (err)
378 		return err;
379 
380 	err = mtk_hw_get_value(hw, desc, PINCTRL_PIN_REG_PD, &v2);
381 	if (err)
382 		return err;
383 
384 	if (v == MTK_ENABLE || v2 == MTK_ENABLE)
385 		return -EINVAL;
386 
387 	*res = 1;
388 
389 	return 0;
390 }
391 
392 int mtk_pinconf_bias_set(struct mtk_pinctrl *hw,
393 			 const struct mtk_pin_desc *desc, bool pullup)
394 {
395 	int err, arg;
396 
397 	arg = pullup ? 1 : 2;
398 
399 	err = mtk_hw_set_value(hw, desc, PINCTRL_PIN_REG_PU, arg & 1);
400 	if (err)
401 		return err;
402 
403 	err = mtk_hw_set_value(hw, desc, PINCTRL_PIN_REG_PD,
404 			       !!(arg & 2));
405 	if (err)
406 		return err;
407 
408 	return 0;
409 }
410 
411 int mtk_pinconf_bias_get(struct mtk_pinctrl *hw,
412 			 const struct mtk_pin_desc *desc, bool pullup, int *res)
413 {
414 	int reg, err, v;
415 
416 	reg = pullup ? PINCTRL_PIN_REG_PU : PINCTRL_PIN_REG_PD;
417 
418 	err = mtk_hw_get_value(hw, desc, reg, &v);
419 	if (err)
420 		return err;
421 
422 	if (!v)
423 		return -EINVAL;
424 
425 	*res = 1;
426 
427 	return 0;
428 }
429 
430 /* Revision 1 */
431 int mtk_pinconf_bias_disable_set_rev1(struct mtk_pinctrl *hw,
432 				      const struct mtk_pin_desc *desc)
433 {
434 	int err;
435 
436 	err = mtk_hw_set_value(hw, desc, PINCTRL_PIN_REG_PULLEN,
437 			       MTK_DISABLE);
438 	if (err)
439 		return err;
440 
441 	return 0;
442 }
443 
444 int mtk_pinconf_bias_disable_get_rev1(struct mtk_pinctrl *hw,
445 				      const struct mtk_pin_desc *desc, int *res)
446 {
447 	int v, err;
448 
449 	err = mtk_hw_get_value(hw, desc, PINCTRL_PIN_REG_PULLEN, &v);
450 	if (err)
451 		return err;
452 
453 	if (v == MTK_ENABLE)
454 		return -EINVAL;
455 
456 	*res = 1;
457 
458 	return 0;
459 }
460 
461 int mtk_pinconf_bias_set_rev1(struct mtk_pinctrl *hw,
462 			      const struct mtk_pin_desc *desc, bool pullup)
463 {
464 	int err, arg;
465 
466 	arg = pullup ? MTK_PULLUP : MTK_PULLDOWN;
467 
468 	err = mtk_hw_set_value(hw, desc, PINCTRL_PIN_REG_PULLEN,
469 			       MTK_ENABLE);
470 	if (err)
471 		return err;
472 
473 	err = mtk_hw_set_value(hw, desc, PINCTRL_PIN_REG_PULLSEL, arg);
474 	if (err)
475 		return err;
476 
477 	return 0;
478 }
479 
480 int mtk_pinconf_bias_get_rev1(struct mtk_pinctrl *hw,
481 			      const struct mtk_pin_desc *desc, bool pullup,
482 			      int *res)
483 {
484 	int err, v;
485 
486 	err = mtk_hw_get_value(hw, desc, PINCTRL_PIN_REG_PULLEN, &v);
487 	if (err)
488 		return err;
489 
490 	if (v == MTK_DISABLE)
491 		return -EINVAL;
492 
493 	err = mtk_hw_get_value(hw, desc, PINCTRL_PIN_REG_PULLSEL, &v);
494 	if (err)
495 		return err;
496 
497 	if (pullup ^ (v == MTK_PULLUP))
498 		return -EINVAL;
499 
500 	*res = 1;
501 
502 	return 0;
503 }
504 
505 /* Revision 0 */
506 int mtk_pinconf_drive_set(struct mtk_pinctrl *hw,
507 			  const struct mtk_pin_desc *desc, u32 arg)
508 {
509 	const struct mtk_drive_desc *tb;
510 	int err = -ENOTSUPP;
511 
512 	tb = &mtk_drive[desc->drv_n];
513 	/* 4mA when (e8, e4) = (0, 0)
514 	 * 8mA when (e8, e4) = (0, 1)
515 	 * 12mA when (e8, e4) = (1, 0)
516 	 * 16mA when (e8, e4) = (1, 1)
517 	 */
518 	if ((arg >= tb->min && arg <= tb->max) && !(arg % tb->step)) {
519 		arg = (arg / tb->step - 1) * tb->scal;
520 		err = mtk_hw_set_value(hw, desc, PINCTRL_PIN_REG_E4,
521 				       arg & 0x1);
522 		if (err)
523 			return err;
524 
525 		err = mtk_hw_set_value(hw, desc, PINCTRL_PIN_REG_E8,
526 				       (arg & 0x2) >> 1);
527 		if (err)
528 			return err;
529 	}
530 
531 	return err;
532 }
533 
534 int mtk_pinconf_drive_get(struct mtk_pinctrl *hw,
535 			  const struct mtk_pin_desc *desc, int *val)
536 {
537 	const struct mtk_drive_desc *tb;
538 	int err, val1, val2;
539 
540 	tb = &mtk_drive[desc->drv_n];
541 
542 	err = mtk_hw_get_value(hw, desc, PINCTRL_PIN_REG_E4, &val1);
543 	if (err)
544 		return err;
545 
546 	err = mtk_hw_get_value(hw, desc, PINCTRL_PIN_REG_E8, &val2);
547 	if (err)
548 		return err;
549 
550 	/* 4mA when (e8, e4) = (0, 0); 8mA when (e8, e4) = (0, 1)
551 	 * 12mA when (e8, e4) = (1, 0); 16mA when (e8, e4) = (1, 1)
552 	 */
553 	*val = (((val2 << 1) + val1) / tb->scal + 1) * tb->step;
554 
555 	return 0;
556 }
557 
558 /* Revision 1 */
559 int mtk_pinconf_drive_set_rev1(struct mtk_pinctrl *hw,
560 			       const struct mtk_pin_desc *desc, u32 arg)
561 {
562 	const struct mtk_drive_desc *tb;
563 	int err = -ENOTSUPP;
564 
565 	tb = &mtk_drive[desc->drv_n];
566 
567 	if ((arg >= tb->min && arg <= tb->max) && !(arg % tb->step)) {
568 		arg = (arg / tb->step - 1) * tb->scal;
569 
570 		err = mtk_hw_set_value(hw, desc, PINCTRL_PIN_REG_DRV,
571 				       arg);
572 		if (err)
573 			return err;
574 	}
575 
576 	return err;
577 }
578 
579 int mtk_pinconf_drive_get_rev1(struct mtk_pinctrl *hw,
580 			       const struct mtk_pin_desc *desc, int *val)
581 {
582 	const struct mtk_drive_desc *tb;
583 	int err, val1;
584 
585 	tb = &mtk_drive[desc->drv_n];
586 
587 	err = mtk_hw_get_value(hw, desc, PINCTRL_PIN_REG_DRV, &val1);
588 	if (err)
589 		return err;
590 
591 	*val = ((val1 & 0x7) / tb->scal + 1) * tb->step;
592 
593 	return 0;
594 }
595 
596 int mtk_pinconf_adv_pull_set(struct mtk_pinctrl *hw,
597 			     const struct mtk_pin_desc *desc, bool pullup,
598 			     u32 arg)
599 {
600 	int err;
601 
602 	/* 10K off & 50K (75K) off, when (R0, R1) = (0, 0);
603 	 * 10K off & 50K (75K) on, when (R0, R1) = (0, 1);
604 	 * 10K on & 50K (75K) off, when (R0, R1) = (1, 0);
605 	 * 10K on & 50K (75K) on, when (R0, R1) = (1, 1)
606 	 */
607 	err = mtk_hw_set_value(hw, desc, PINCTRL_PIN_REG_R0, arg & 1);
608 	if (err)
609 		return 0;
610 
611 	err = mtk_hw_set_value(hw, desc, PINCTRL_PIN_REG_R1,
612 			       !!(arg & 2));
613 	if (err)
614 		return 0;
615 
616 	arg = pullup ? 0 : 1;
617 
618 	err = mtk_hw_set_value(hw, desc, PINCTRL_PIN_REG_PUPD, arg);
619 
620 	/* If PUPD register is not supported for that pin, let's fallback to
621 	 * general bias control.
622 	 */
623 	if (err == -ENOTSUPP) {
624 		if (hw->soc->bias_set) {
625 			err = hw->soc->bias_set(hw, desc, pullup);
626 			if (err)
627 				return err;
628 		} else {
629 			return -ENOTSUPP;
630 		}
631 	}
632 
633 	return err;
634 }
635 
636 int mtk_pinconf_adv_pull_get(struct mtk_pinctrl *hw,
637 			     const struct mtk_pin_desc *desc, bool pullup,
638 			     u32 *val)
639 {
640 	u32 t, t2;
641 	int err;
642 
643 	err = mtk_hw_get_value(hw, desc, PINCTRL_PIN_REG_PUPD, &t);
644 
645 	/* If PUPD register is not supported for that pin, let's fallback to
646 	 * general bias control.
647 	 */
648 	if (err == -ENOTSUPP) {
649 		if (hw->soc->bias_get) {
650 			err = hw->soc->bias_get(hw, desc, pullup, val);
651 			if (err)
652 				return err;
653 		} else {
654 			return -ENOTSUPP;
655 		}
656 	} else {
657 		/* t == 0 supposes PULLUP for the customized PULL setup */
658 		if (err)
659 			return err;
660 
661 		if (pullup ^ !t)
662 			return -EINVAL;
663 	}
664 
665 	err = mtk_hw_get_value(hw, desc, PINCTRL_PIN_REG_R0, &t);
666 	if (err)
667 		return err;
668 
669 	err = mtk_hw_get_value(hw, desc, PINCTRL_PIN_REG_R1, &t2);
670 	if (err)
671 		return err;
672 
673 	*val = (t | t2 << 1) & 0x7;
674 
675 	return 0;
676 }
677