1 /*
2  * Pinctrl driver for the Wondermedia SoC's
3  *
4  * Copyright (c) 2013 Tony Prisk <linux@prisktech.co.nz>
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms and conditions of the GNU General Public License,
8  * version 2, as published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope it will be useful, but WITHOUT
11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
13  * more details.
14  */
15 
16 #include <linux/err.h>
17 #include <linux/gpio.h>
18 #include <linux/interrupt.h>
19 #include <linux/io.h>
20 #include <linux/irq.h>
21 #include <linux/module.h>
22 #include <linux/of.h>
23 #include <linux/of_irq.h>
24 #include <linux/pinctrl/consumer.h>
25 #include <linux/pinctrl/machine.h>
26 #include <linux/pinctrl/pinconf.h>
27 #include <linux/pinctrl/pinconf-generic.h>
28 #include <linux/pinctrl/pinctrl.h>
29 #include <linux/pinctrl/pinmux.h>
30 #include <linux/platform_device.h>
31 #include <linux/slab.h>
32 
33 #include "pinctrl-wmt.h"
34 
35 static inline void wmt_setbits(struct wmt_pinctrl_data *data, u32 reg,
36 				 u32 mask)
37 {
38 	u32 val;
39 
40 	val = readl_relaxed(data->base + reg);
41 	val |= mask;
42 	writel_relaxed(val, data->base + reg);
43 }
44 
45 static inline void wmt_clearbits(struct wmt_pinctrl_data *data, u32 reg,
46 				   u32 mask)
47 {
48 	u32 val;
49 
50 	val = readl_relaxed(data->base + reg);
51 	val &= ~mask;
52 	writel_relaxed(val, data->base + reg);
53 }
54 
55 enum wmt_func_sel {
56 	WMT_FSEL_GPIO_IN = 0,
57 	WMT_FSEL_GPIO_OUT = 1,
58 	WMT_FSEL_ALT = 2,
59 	WMT_FSEL_COUNT = 3,
60 };
61 
62 static const char * const wmt_functions[WMT_FSEL_COUNT] = {
63 	[WMT_FSEL_GPIO_IN] = "gpio_in",
64 	[WMT_FSEL_GPIO_OUT] = "gpio_out",
65 	[WMT_FSEL_ALT] = "alt",
66 };
67 
68 static int wmt_pmx_get_functions_count(struct pinctrl_dev *pctldev)
69 {
70 	return WMT_FSEL_COUNT;
71 }
72 
73 static const char *wmt_pmx_get_function_name(struct pinctrl_dev *pctldev,
74 					     unsigned selector)
75 {
76 	return wmt_functions[selector];
77 }
78 
79 static int wmt_pmx_get_function_groups(struct pinctrl_dev *pctldev,
80 				       unsigned selector,
81 				       const char * const **groups,
82 				       unsigned * const num_groups)
83 {
84 	struct wmt_pinctrl_data *data = pinctrl_dev_get_drvdata(pctldev);
85 
86 	/* every pin does every function */
87 	*groups = data->groups;
88 	*num_groups = data->ngroups;
89 
90 	return 0;
91 }
92 
93 static int wmt_set_pinmux(struct wmt_pinctrl_data *data, unsigned func,
94 			  unsigned pin)
95 {
96 	u32 bank = WMT_BANK_FROM_PIN(pin);
97 	u32 bit = WMT_BIT_FROM_PIN(pin);
98 	u32 reg_en = data->banks[bank].reg_en;
99 	u32 reg_dir = data->banks[bank].reg_dir;
100 
101 	if (reg_dir == NO_REG) {
102 		dev_err(data->dev, "pin:%d no direction register defined\n",
103 			pin);
104 		return -EINVAL;
105 	}
106 
107 	/*
108 	 * If reg_en == NO_REG, we assume it is a dedicated GPIO and cannot be
109 	 * disabled (as on VT8500) and that no alternate function is available.
110 	 */
111 	switch (func) {
112 	case WMT_FSEL_GPIO_IN:
113 		if (reg_en != NO_REG)
114 			wmt_setbits(data, reg_en, BIT(bit));
115 		wmt_clearbits(data, reg_dir, BIT(bit));
116 		break;
117 	case WMT_FSEL_GPIO_OUT:
118 		if (reg_en != NO_REG)
119 			wmt_setbits(data, reg_en, BIT(bit));
120 		wmt_setbits(data, reg_dir, BIT(bit));
121 		break;
122 	case WMT_FSEL_ALT:
123 		if (reg_en == NO_REG) {
124 			dev_err(data->dev, "pin:%d no alt function available\n",
125 				pin);
126 			return -EINVAL;
127 		}
128 		wmt_clearbits(data, reg_en, BIT(bit));
129 	}
130 
131 	return 0;
132 }
133 
134 static int wmt_pmx_enable(struct pinctrl_dev *pctldev,
135 			  unsigned func_selector,
136 			  unsigned group_selector)
137 {
138 	struct wmt_pinctrl_data *data = pinctrl_dev_get_drvdata(pctldev);
139 	u32 pinnum = data->pins[group_selector].number;
140 
141 	return wmt_set_pinmux(data, func_selector, pinnum);
142 }
143 
144 static void wmt_pmx_disable(struct pinctrl_dev *pctldev,
145 			    unsigned func_selector,
146 			    unsigned group_selector)
147 {
148 	struct wmt_pinctrl_data *data = pinctrl_dev_get_drvdata(pctldev);
149 	u32 pinnum = data->pins[group_selector].number;
150 
151 	/* disable by setting GPIO_IN */
152 	wmt_set_pinmux(data, WMT_FSEL_GPIO_IN, pinnum);
153 }
154 
155 static void wmt_pmx_gpio_disable_free(struct pinctrl_dev *pctldev,
156 				      struct pinctrl_gpio_range *range,
157 				      unsigned offset)
158 {
159 	struct wmt_pinctrl_data *data = pinctrl_dev_get_drvdata(pctldev);
160 
161 	/* disable by setting GPIO_IN */
162 	wmt_set_pinmux(data, WMT_FSEL_GPIO_IN, offset);
163 }
164 
165 static int wmt_pmx_gpio_set_direction(struct pinctrl_dev *pctldev,
166 				      struct pinctrl_gpio_range *range,
167 				      unsigned offset,
168 				      bool input)
169 {
170 	struct wmt_pinctrl_data *data = pinctrl_dev_get_drvdata(pctldev);
171 
172 	wmt_set_pinmux(data, (input ? WMT_FSEL_GPIO_IN : WMT_FSEL_GPIO_OUT),
173 		       offset);
174 
175 	return 0;
176 }
177 
178 static struct pinmux_ops wmt_pinmux_ops = {
179 	.get_functions_count = wmt_pmx_get_functions_count,
180 	.get_function_name = wmt_pmx_get_function_name,
181 	.get_function_groups = wmt_pmx_get_function_groups,
182 	.enable = wmt_pmx_enable,
183 	.disable = wmt_pmx_disable,
184 	.gpio_disable_free = wmt_pmx_gpio_disable_free,
185 	.gpio_set_direction = wmt_pmx_gpio_set_direction,
186 };
187 
188 static int wmt_get_groups_count(struct pinctrl_dev *pctldev)
189 {
190 	struct wmt_pinctrl_data *data = pinctrl_dev_get_drvdata(pctldev);
191 
192 	return data->ngroups;
193 }
194 
195 static const char *wmt_get_group_name(struct pinctrl_dev *pctldev,
196 				      unsigned selector)
197 {
198 	struct wmt_pinctrl_data *data = pinctrl_dev_get_drvdata(pctldev);
199 
200 	return data->groups[selector];
201 }
202 
203 static int wmt_get_group_pins(struct pinctrl_dev *pctldev,
204 			      unsigned selector,
205 			      const unsigned **pins,
206 			      unsigned *num_pins)
207 {
208 	struct wmt_pinctrl_data *data = pinctrl_dev_get_drvdata(pctldev);
209 
210 	*pins = &data->pins[selector].number;
211 	*num_pins = 1;
212 
213 	return 0;
214 }
215 
216 static int wmt_pctl_find_group_by_pin(struct wmt_pinctrl_data *data, u32 pin)
217 {
218 	int i;
219 
220 	for (i = 0; i < data->npins; i++) {
221 		if (data->pins[i].number == pin)
222 			return i;
223 	}
224 
225 	return -EINVAL;
226 }
227 
228 static int wmt_pctl_dt_node_to_map_func(struct wmt_pinctrl_data *data,
229 					struct device_node *np,
230 					u32 pin, u32 fnum,
231 					struct pinctrl_map **maps)
232 {
233 	int group;
234 	struct pinctrl_map *map = *maps;
235 
236 	if (fnum >= ARRAY_SIZE(wmt_functions)) {
237 		dev_err(data->dev, "invalid wm,function %d\n", fnum);
238 		return -EINVAL;
239 	}
240 
241 	group = wmt_pctl_find_group_by_pin(data, pin);
242 	if (group < 0) {
243 		dev_err(data->dev, "unable to match pin %d to group\n", pin);
244 		return group;
245 	}
246 
247 	map->type = PIN_MAP_TYPE_MUX_GROUP;
248 	map->data.mux.group = data->groups[group];
249 	map->data.mux.function = wmt_functions[fnum];
250 	(*maps)++;
251 
252 	return 0;
253 }
254 
255 static int wmt_pctl_dt_node_to_map_pull(struct wmt_pinctrl_data *data,
256 					struct device_node *np,
257 					u32 pin, u32 pull,
258 					struct pinctrl_map **maps)
259 {
260 	int group;
261 	unsigned long *configs;
262 	struct pinctrl_map *map = *maps;
263 
264 	if (pull > 2) {
265 		dev_err(data->dev, "invalid wm,pull %d\n", pull);
266 		return -EINVAL;
267 	}
268 
269 	group = wmt_pctl_find_group_by_pin(data, pin);
270 	if (group < 0) {
271 		dev_err(data->dev, "unable to match pin %d to group\n", pin);
272 		return group;
273 	}
274 
275 	configs = kzalloc(sizeof(*configs), GFP_KERNEL);
276 	if (!configs)
277 		return -ENOMEM;
278 
279 	configs[0] = pull;
280 
281 	map->type = PIN_MAP_TYPE_CONFIGS_PIN;
282 	map->data.configs.group_or_pin = data->groups[group];
283 	map->data.configs.configs = configs;
284 	map->data.configs.num_configs = 1;
285 	(*maps)++;
286 
287 	return 0;
288 }
289 
290 static void wmt_pctl_dt_free_map(struct pinctrl_dev *pctldev,
291 				 struct pinctrl_map *maps,
292 				 unsigned num_maps)
293 {
294 	int i;
295 
296 	for (i = 0; i < num_maps; i++)
297 		if (maps[i].type == PIN_MAP_TYPE_CONFIGS_PIN)
298 			kfree(maps[i].data.configs.configs);
299 
300 	kfree(maps);
301 }
302 
303 static int wmt_pctl_dt_node_to_map(struct pinctrl_dev *pctldev,
304 				   struct device_node *np,
305 				   struct pinctrl_map **map,
306 				   unsigned *num_maps)
307 {
308 	struct pinctrl_map *maps, *cur_map;
309 	struct property *pins, *funcs, *pulls;
310 	u32 pin, func, pull;
311 	int num_pins, num_funcs, num_pulls, maps_per_pin;
312 	int i, err;
313 	struct wmt_pinctrl_data *data = pinctrl_dev_get_drvdata(pctldev);
314 
315 	pins = of_find_property(np, "wm,pins", NULL);
316 	if (!pins) {
317 		dev_err(data->dev, "missing wmt,pins property\n");
318 		return -EINVAL;
319 	}
320 
321 	funcs = of_find_property(np, "wm,function", NULL);
322 	pulls = of_find_property(np, "wm,pull", NULL);
323 
324 	if (!funcs && !pulls) {
325 		dev_err(data->dev, "neither wm,function nor wm,pull specified\n");
326 		return -EINVAL;
327 	}
328 
329 	/*
330 	 * The following lines calculate how many values are defined for each
331 	 * of the properties.
332 	 */
333 	num_pins = pins->length / sizeof(u32);
334 	num_funcs = funcs ? (funcs->length / sizeof(u32)) : 0;
335 	num_pulls = pulls ? (pulls->length / sizeof(u32)) : 0;
336 
337 	if (num_funcs > 1 && num_funcs != num_pins) {
338 		dev_err(data->dev, "wm,function must have 1 or %d entries\n",
339 			num_pins);
340 		return -EINVAL;
341 	}
342 
343 	if (num_pulls > 1 && num_pulls != num_pins) {
344 		dev_err(data->dev, "wm,pull must have 1 or %d entries\n",
345 			num_pins);
346 		return -EINVAL;
347 	}
348 
349 	maps_per_pin = 0;
350 	if (num_funcs)
351 		maps_per_pin++;
352 	if (num_pulls)
353 		maps_per_pin++;
354 
355 	cur_map = maps = kzalloc(num_pins * maps_per_pin * sizeof(*maps),
356 				 GFP_KERNEL);
357 	if (!maps)
358 		return -ENOMEM;
359 
360 	for (i = 0; i < num_pins; i++) {
361 		err = of_property_read_u32_index(np, "wm,pins", i, &pin);
362 		if (err)
363 			goto fail;
364 
365 		if (pin >= (data->nbanks * 32)) {
366 			dev_err(data->dev, "invalid wm,pins value\n");
367 			err = -EINVAL;
368 			goto fail;
369 		}
370 
371 		if (num_funcs) {
372 			err = of_property_read_u32_index(np, "wm,function",
373 						(num_funcs > 1 ? i : 0), &func);
374 			if (err)
375 				goto fail;
376 
377 			err = wmt_pctl_dt_node_to_map_func(data, np, pin, func,
378 							   &cur_map);
379 			if (err)
380 				goto fail;
381 		}
382 
383 		if (num_pulls) {
384 			err = of_property_read_u32_index(np, "wm,pull",
385 						(num_pulls > 1 ? i : 0), &pull);
386 			if (err)
387 				goto fail;
388 
389 			err = wmt_pctl_dt_node_to_map_pull(data, np, pin, pull,
390 							   &cur_map);
391 			if (err)
392 				goto fail;
393 		}
394 	}
395 	*map = maps;
396 	*num_maps = num_pins * maps_per_pin;
397 	return 0;
398 
399 /*
400  * The fail path removes any maps that have been allocated. The fail path is
401  * only called from code after maps has been kzalloc'd. It is also safe to
402  * pass 'num_pins * maps_per_pin' as the map count even though we probably
403  * failed before all the mappings were read as all maps are allocated at once,
404  * and configs are only allocated for .type = PIN_MAP_TYPE_CONFIGS_PIN - there
405  * is no failpath where a config can be allocated without .type being set.
406  */
407 fail:
408 	wmt_pctl_dt_free_map(pctldev, maps, num_pins * maps_per_pin);
409 	return err;
410 }
411 
412 static struct pinctrl_ops wmt_pctl_ops = {
413 	.get_groups_count = wmt_get_groups_count,
414 	.get_group_name	= wmt_get_group_name,
415 	.get_group_pins	= wmt_get_group_pins,
416 	.dt_node_to_map = wmt_pctl_dt_node_to_map,
417 	.dt_free_map = wmt_pctl_dt_free_map,
418 };
419 
420 static int wmt_pinconf_get(struct pinctrl_dev *pctldev, unsigned pin,
421 			   unsigned long *config)
422 {
423 	return -ENOTSUPP;
424 }
425 
426 static int wmt_pinconf_set(struct pinctrl_dev *pctldev, unsigned pin,
427 			   unsigned long *configs, unsigned num_configs)
428 {
429 	struct wmt_pinctrl_data *data = pinctrl_dev_get_drvdata(pctldev);
430 	enum pin_config_param param;
431 	u16 arg;
432 	u32 bank = WMT_BANK_FROM_PIN(pin);
433 	u32 bit = WMT_BIT_FROM_PIN(pin);
434 	u32 reg_pull_en = data->banks[bank].reg_pull_en;
435 	u32 reg_pull_cfg = data->banks[bank].reg_pull_cfg;
436 	int i;
437 
438 	if ((reg_pull_en == NO_REG) || (reg_pull_cfg == NO_REG)) {
439 		dev_err(data->dev, "bias functions not supported on pin %d\n",
440 			pin);
441 		return -EINVAL;
442 	}
443 
444 	for (i = 0; i < num_configs; i++) {
445 		param = pinconf_to_config_param(configs[i]);
446 		arg = pinconf_to_config_argument(configs[i]);
447 
448 		if ((param == PIN_CONFIG_BIAS_PULL_DOWN) ||
449 		    (param == PIN_CONFIG_BIAS_PULL_UP)) {
450 			if (arg == 0)
451 				param = PIN_CONFIG_BIAS_DISABLE;
452 		}
453 
454 		switch (param) {
455 		case PIN_CONFIG_BIAS_DISABLE:
456 			wmt_clearbits(data, reg_pull_en, BIT(bit));
457 			break;
458 		case PIN_CONFIG_BIAS_PULL_DOWN:
459 			wmt_clearbits(data, reg_pull_cfg, BIT(bit));
460 			wmt_setbits(data, reg_pull_en, BIT(bit));
461 			break;
462 		case PIN_CONFIG_BIAS_PULL_UP:
463 			wmt_setbits(data, reg_pull_cfg, BIT(bit));
464 			wmt_setbits(data, reg_pull_en, BIT(bit));
465 			break;
466 		default:
467 			dev_err(data->dev, "unknown pinconf param\n");
468 			return -EINVAL;
469 		}
470 	} /* for each config */
471 
472 	return 0;
473 }
474 
475 static struct pinconf_ops wmt_pinconf_ops = {
476 	.pin_config_get = wmt_pinconf_get,
477 	.pin_config_set = wmt_pinconf_set,
478 };
479 
480 static struct pinctrl_desc wmt_desc = {
481 	.owner = THIS_MODULE,
482 	.name = "pinctrl-wmt",
483 	.pctlops = &wmt_pctl_ops,
484 	.pmxops = &wmt_pinmux_ops,
485 	.confops = &wmt_pinconf_ops,
486 };
487 
488 static int wmt_gpio_request(struct gpio_chip *chip, unsigned offset)
489 {
490 	return pinctrl_request_gpio(chip->base + offset);
491 }
492 
493 static void wmt_gpio_free(struct gpio_chip *chip, unsigned offset)
494 {
495 	pinctrl_free_gpio(chip->base + offset);
496 }
497 
498 static int wmt_gpio_get_direction(struct gpio_chip *chip, unsigned offset)
499 {
500 	struct wmt_pinctrl_data *data = dev_get_drvdata(chip->dev);
501 	u32 bank = WMT_BANK_FROM_PIN(offset);
502 	u32 bit = WMT_BIT_FROM_PIN(offset);
503 	u32 reg_dir = data->banks[bank].reg_dir;
504 	u32 val;
505 
506 	val = readl_relaxed(data->base + reg_dir);
507 	if (val & BIT(bit))
508 		return GPIOF_DIR_OUT;
509 	else
510 		return GPIOF_DIR_IN;
511 }
512 
513 static int wmt_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
514 {
515 	return pinctrl_gpio_direction_input(chip->base + offset);
516 }
517 
518 static int wmt_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
519 				     int value)
520 {
521 	return pinctrl_gpio_direction_output(chip->base + offset);
522 }
523 
524 static int wmt_gpio_get_value(struct gpio_chip *chip, unsigned offset)
525 {
526 	struct wmt_pinctrl_data *data = dev_get_drvdata(chip->dev);
527 	u32 bank = WMT_BANK_FROM_PIN(offset);
528 	u32 bit = WMT_BIT_FROM_PIN(offset);
529 	u32 reg_data_in = data->banks[bank].reg_data_in;
530 
531 	if (reg_data_in == NO_REG) {
532 		dev_err(data->dev, "no data in register defined\n");
533 		return -EINVAL;
534 	}
535 
536 	return !!(readl_relaxed(data->base + reg_data_in) & BIT(bit));
537 }
538 
539 static void wmt_gpio_set_value(struct gpio_chip *chip, unsigned offset,
540 			       int val)
541 {
542 	struct wmt_pinctrl_data *data = dev_get_drvdata(chip->dev);
543 	u32 bank = WMT_BANK_FROM_PIN(offset);
544 	u32 bit = WMT_BIT_FROM_PIN(offset);
545 	u32 reg_data_out = data->banks[bank].reg_data_out;
546 
547 	if (reg_data_out == NO_REG) {
548 		dev_err(data->dev, "no data out register defined\n");
549 		return;
550 	}
551 
552 	if (val)
553 		wmt_setbits(data, reg_data_out, BIT(bit));
554 	else
555 		wmt_clearbits(data, reg_data_out, BIT(bit));
556 }
557 
558 static struct gpio_chip wmt_gpio_chip = {
559 	.label = "gpio-wmt",
560 	.owner = THIS_MODULE,
561 	.request = wmt_gpio_request,
562 	.free = wmt_gpio_free,
563 	.get_direction = wmt_gpio_get_direction,
564 	.direction_input = wmt_gpio_direction_input,
565 	.direction_output = wmt_gpio_direction_output,
566 	.get = wmt_gpio_get_value,
567 	.set = wmt_gpio_set_value,
568 	.can_sleep = 0,
569 };
570 
571 int wmt_pinctrl_probe(struct platform_device *pdev,
572 		      struct wmt_pinctrl_data *data)
573 {
574 	int err;
575 	struct resource *res;
576 
577 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
578 	data->base = devm_ioremap_resource(&pdev->dev, res);
579 	if (IS_ERR(data->base))
580 		return PTR_ERR(data->base);
581 
582 	wmt_desc.pins = data->pins;
583 	wmt_desc.npins = data->npins;
584 
585 	data->gpio_chip = wmt_gpio_chip;
586 	data->gpio_chip.dev = &pdev->dev;
587 	data->gpio_chip.of_node = pdev->dev.of_node;
588 	data->gpio_chip.ngpio = data->nbanks * 32;
589 
590 	platform_set_drvdata(pdev, data);
591 
592 	data->dev = &pdev->dev;
593 
594 	data->pctl_dev = pinctrl_register(&wmt_desc, &pdev->dev, data);
595 	if (!data->pctl_dev) {
596 		dev_err(&pdev->dev, "Failed to register pinctrl\n");
597 		return -EINVAL;
598 	}
599 
600 	err = gpiochip_add(&data->gpio_chip);
601 	if (err) {
602 		dev_err(&pdev->dev, "could not add GPIO chip\n");
603 		goto fail_gpio;
604 	}
605 
606 	err = gpiochip_add_pin_range(&data->gpio_chip, dev_name(data->dev),
607 				     0, 0, data->nbanks * 32);
608 	if (err)
609 		goto fail_range;
610 
611 	dev_info(&pdev->dev, "Pin controller initialized\n");
612 
613 	return 0;
614 
615 fail_range:
616 	if (gpiochip_remove(&data->gpio_chip))
617 		dev_err(&pdev->dev, "failed to remove gpio chip\n");
618 fail_gpio:
619 	pinctrl_unregister(data->pctl_dev);
620 	return err;
621 }
622 
623 int wmt_pinctrl_remove(struct platform_device *pdev)
624 {
625 	struct wmt_pinctrl_data *data = platform_get_drvdata(pdev);
626 	int err;
627 
628 	err = gpiochip_remove(&data->gpio_chip);
629 	if (err)
630 		dev_err(&pdev->dev, "failed to remove gpio chip\n");
631 
632 	pinctrl_unregister(data->pctl_dev);
633 
634 	return 0;
635 }
636