1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Apple SoC pinctrl+GPIO+external IRQ driver
4  *
5  * Copyright (C) The Asahi Linux Contributors
6  * Copyright (C) 2020 Corellium LLC
7  *
8  * Based on: pinctrl-pistachio.c
9  * Copyright (C) 2014 Imagination Technologies Ltd.
10  * Copyright (C) 2014 Google, Inc.
11  */
12 
13 #include <dt-bindings/pinctrl/apple.h>
14 #include <linux/gpio/driver.h>
15 #include <linux/interrupt.h>
16 #include <linux/irq.h>
17 #include <linux/module.h>
18 #include <linux/of.h>
19 #include <linux/of_irq.h>
20 #include <linux/pinctrl/pinctrl.h>
21 #include <linux/pinctrl/pinmux.h>
22 #include <linux/platform_device.h>
23 #include <linux/regmap.h>
24 
25 #include "pinctrl-utils.h"
26 #include "core.h"
27 #include "pinmux.h"
28 
29 struct apple_gpio_pinctrl {
30 	struct device *dev;
31 	struct pinctrl_dev *pctldev;
32 
33 	void __iomem *base;
34 	struct regmap *map;
35 
36 	struct pinctrl_desc pinctrl_desc;
37 	struct gpio_chip gpio_chip;
38 	struct irq_chip irq_chip;
39 	u8 irqgrps[0];
40 };
41 
42 #define REG_GPIO(x)          (4 * (x))
43 #define REG_GPIOx_DATA       BIT(0)
44 #define REG_GPIOx_MODE       GENMASK(3, 1)
45 #define REG_GPIOx_OUT        1
46 #define REG_GPIOx_IN_IRQ_HI  2
47 #define REG_GPIOx_IN_IRQ_LO  3
48 #define REG_GPIOx_IN_IRQ_UP  4
49 #define REG_GPIOx_IN_IRQ_DN  5
50 #define REG_GPIOx_IN_IRQ_ANY 6
51 #define REG_GPIOx_IN_IRQ_OFF 7
52 #define REG_GPIOx_PERIPH     GENMASK(6, 5)
53 #define REG_GPIOx_PULL       GENMASK(8, 7)
54 #define REG_GPIOx_PULL_OFF   0
55 #define REG_GPIOx_PULL_DOWN  1
56 #define REG_GPIOx_PULL_UP_STRONG 2
57 #define REG_GPIOx_PULL_UP    3
58 #define REG_GPIOx_INPUT_ENABLE BIT(9)
59 #define REG_GPIOx_DRIVE_STRENGTH0 GENMASK(11, 10)
60 #define REG_GPIOx_SCHMITT    BIT(15)
61 #define REG_GPIOx_GRP        GENMASK(18, 16)
62 #define REG_GPIOx_LOCK       BIT(21)
63 #define REG_GPIOx_DRIVE_STRENGTH1 GENMASK(23, 22)
64 #define REG_IRQ(g, x)        (0x800 + 0x40 * (g) + 4 * ((x) >> 5))
65 
66 struct regmap_config regmap_config = {
67 	.reg_bits = 32,
68 	.val_bits = 32,
69 	.reg_stride = 4,
70 	.cache_type = REGCACHE_FLAT,
71 	.max_register = 512 * sizeof(u32),
72 	.num_reg_defaults_raw = 512,
73 	.use_relaxed_mmio = true
74 };
75 
76 // No locking needed to mask/unmask IRQs as the interrupt mode is per pin-register.
77 static void apple_gpio_set_reg(struct apple_gpio_pinctrl *pctl,
78 			       unsigned int pin, u32 mask, u32 value)
79 {
80 	regmap_update_bits(pctl->map, REG_GPIO(pin), mask, value);
81 }
82 
83 static uint32_t apple_gpio_get_reg(struct apple_gpio_pinctrl *pctl,
84 				   unsigned int pin)
85 {
86 	unsigned int val = 0;
87 
88 	regmap_read(pctl->map, REG_GPIO(pin), &val);
89 	return val;
90 }
91 
92 /* Pin controller functions */
93 
94 static int apple_gpio_dt_node_to_map(struct pinctrl_dev *pctldev,
95 				     struct device_node *node,
96 				     struct pinctrl_map **map,
97 				     unsigned *num_maps)
98 {
99 	unsigned reserved_maps;
100 	struct apple_gpio_pinctrl *pctl;
101 	u32 pinfunc, pin, func;
102 	int num_pins, i, ret;
103 	const char *group_name;
104 	const char *function_name;
105 
106 	*map = NULL;
107 	*num_maps = 0;
108 	reserved_maps = 0;
109 
110 	pctl = pinctrl_dev_get_drvdata(pctldev);
111 
112 	ret = of_property_count_u32_elems(node, "pinmux");
113 	if (ret <= 0) {
114 		dev_err(pctl->dev,
115 			"missing or empty pinmux property in node %pOFn.\n",
116 			node);
117 		return ret;
118 	}
119 
120 	num_pins = ret;
121 
122 	ret = pinctrl_utils_reserve_map(pctldev, map, &reserved_maps, num_maps,
123 					num_pins);
124 	if (ret)
125 		return ret;
126 
127 	for (i = 0; i < num_pins; i++) {
128 		ret = of_property_read_u32_index(node, "pinmux", i, &pinfunc);
129 		if (ret)
130 			goto free_map;
131 
132 		pin = APPLE_PIN(pinfunc);
133 		func = APPLE_FUNC(pinfunc);
134 
135 		if (func >= pinmux_generic_get_function_count(pctldev)) {
136 			ret = -EINVAL;
137 			goto free_map;
138 		}
139 
140 		group_name = pinctrl_generic_get_group_name(pctldev, pin);
141 		function_name =
142 			pinmux_generic_get_function_name(pctl->pctldev, func);
143 		ret = pinctrl_utils_add_map_mux(pctl->pctldev, map,
144 						&reserved_maps, num_maps,
145 						group_name, function_name);
146 		if (ret)
147 			goto free_map;
148 	}
149 
150 free_map:
151 	if (ret < 0)
152 		pinctrl_utils_free_map(pctldev, *map, *num_maps);
153 
154 	return ret;
155 }
156 
157 static const struct pinctrl_ops apple_gpio_pinctrl_ops = {
158 	.get_groups_count = pinctrl_generic_get_group_count,
159 	.get_group_name = pinctrl_generic_get_group_name,
160 	.get_group_pins = pinctrl_generic_get_group_pins,
161 	.dt_node_to_map = apple_gpio_dt_node_to_map,
162 	.dt_free_map = pinctrl_utils_free_map,
163 };
164 
165 /* Pin multiplexer functions */
166 
167 static int apple_gpio_pinmux_set(struct pinctrl_dev *pctldev, unsigned func,
168 				    unsigned group)
169 {
170 	struct apple_gpio_pinctrl *pctl = pinctrl_dev_get_drvdata(pctldev);
171 
172 	apple_gpio_set_reg(
173 		pctl, group, REG_GPIOx_PERIPH | REG_GPIOx_INPUT_ENABLE,
174 		FIELD_PREP(REG_GPIOx_PERIPH, func) | REG_GPIOx_INPUT_ENABLE);
175 
176 	return 0;
177 }
178 
179 static const struct pinmux_ops apple_gpio_pinmux_ops = {
180 	.get_functions_count = pinmux_generic_get_function_count,
181 	.get_function_name = pinmux_generic_get_function_name,
182 	.get_function_groups = pinmux_generic_get_function_groups,
183 	.set_mux = apple_gpio_pinmux_set,
184 	.strict = true,
185 };
186 
187 /* GPIO chip functions */
188 
189 static int apple_gpio_get_direction(struct gpio_chip *chip,
190 					 unsigned int offset)
191 {
192 	struct apple_gpio_pinctrl *pctl = gpiochip_get_data(chip);
193 	unsigned int reg = apple_gpio_get_reg(pctl, offset);
194 
195 	return (FIELD_GET(REG_GPIOx_MODE, reg) == REG_GPIOx_OUT) ?
196 		       GPIO_LINE_DIRECTION_OUT : GPIO_LINE_DIRECTION_IN;
197 }
198 
199 static int apple_gpio_get(struct gpio_chip *chip, unsigned offset)
200 {
201 	struct apple_gpio_pinctrl *pctl = gpiochip_get_data(chip);
202 	unsigned int reg = apple_gpio_get_reg(pctl, offset);
203 
204 	/*
205 	 * If this is an input GPIO, read the actual value (not the
206 	 * cached regmap value)
207 	 */
208 	if (FIELD_GET(REG_GPIOx_MODE, reg) != REG_GPIOx_OUT)
209 		reg = readl_relaxed(pctl->base + REG_GPIO(offset));
210 
211 	return !!(reg & REG_GPIOx_DATA);
212 }
213 
214 static void apple_gpio_set(struct gpio_chip *chip, unsigned int offset,
215 				int value)
216 {
217 	struct apple_gpio_pinctrl *pctl = gpiochip_get_data(chip);
218 
219 	apple_gpio_set_reg(pctl, offset, REG_GPIOx_DATA,
220 			   value ? REG_GPIOx_DATA : 0);
221 }
222 
223 static int apple_gpio_direction_input(struct gpio_chip *chip,
224 					   unsigned int offset)
225 {
226 	struct apple_gpio_pinctrl *pctl = gpiochip_get_data(chip);
227 
228 	apple_gpio_set_reg(pctl, offset,
229 			   REG_GPIOx_PERIPH | REG_GPIOx_MODE | REG_GPIOx_DATA |
230 				   REG_GPIOx_INPUT_ENABLE,
231 			   FIELD_PREP(REG_GPIOx_MODE, REG_GPIOx_IN_IRQ_OFF) |
232 				   REG_GPIOx_INPUT_ENABLE);
233 	return 0;
234 }
235 
236 static int apple_gpio_direction_output(struct gpio_chip *chip,
237 					    unsigned int offset, int value)
238 {
239 	struct apple_gpio_pinctrl *pctl = gpiochip_get_data(chip);
240 
241 	apple_gpio_set_reg(pctl, offset,
242 			   REG_GPIOx_PERIPH | REG_GPIOx_MODE | REG_GPIOx_DATA,
243 			   FIELD_PREP(REG_GPIOx_MODE, REG_GPIOx_OUT) |
244 				   (value ? REG_GPIOx_DATA : 0));
245 	return 0;
246 }
247 
248 /* IRQ chip functions */
249 
250 static void apple_gpio_irq_ack(struct irq_data *data)
251 {
252 	struct apple_gpio_pinctrl *pctl =
253 		gpiochip_get_data(irq_data_get_irq_chip_data(data));
254 	unsigned int irqgrp =
255 		FIELD_GET(REG_GPIOx_GRP, apple_gpio_get_reg(pctl, data->hwirq));
256 
257 	writel(BIT(data->hwirq & 31),
258 	       pctl->base + REG_IRQ(irqgrp, data->hwirq));
259 }
260 
261 static int apple_gpio_irq_type(unsigned int type)
262 {
263 	switch (type & IRQ_TYPE_SENSE_MASK) {
264 	case IRQ_TYPE_EDGE_RISING:
265 		return REG_GPIOx_IN_IRQ_UP;
266 	case IRQ_TYPE_EDGE_FALLING:
267 		return REG_GPIOx_IN_IRQ_DN;
268 	case IRQ_TYPE_EDGE_BOTH:
269 		return REG_GPIOx_IN_IRQ_ANY;
270 	case IRQ_TYPE_LEVEL_HIGH:
271 		return REG_GPIOx_IN_IRQ_HI;
272 	case IRQ_TYPE_LEVEL_LOW:
273 		return REG_GPIOx_IN_IRQ_LO;
274 	default:
275 		return -EINVAL;
276 	}
277 }
278 
279 static void apple_gpio_irq_mask(struct irq_data *data)
280 {
281 	struct apple_gpio_pinctrl *pctl =
282 		gpiochip_get_data(irq_data_get_irq_chip_data(data));
283 	apple_gpio_set_reg(pctl, data->hwirq, REG_GPIOx_MODE,
284 			   FIELD_PREP(REG_GPIOx_MODE, REG_GPIOx_IN_IRQ_OFF));
285 }
286 
287 static void apple_gpio_irq_unmask(struct irq_data *data)
288 {
289 	struct apple_gpio_pinctrl *pctl =
290 		gpiochip_get_data(irq_data_get_irq_chip_data(data));
291 	int irqtype = apple_gpio_irq_type(irqd_get_trigger_type(data));
292 
293 	apple_gpio_set_reg(pctl, data->hwirq, REG_GPIOx_MODE,
294 			   FIELD_PREP(REG_GPIOx_MODE, irqtype));
295 }
296 
297 static unsigned int apple_gpio_irq_startup(struct irq_data *data)
298 {
299 	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
300 	struct apple_gpio_pinctrl *pctl = gpiochip_get_data(chip);
301 
302 	apple_gpio_set_reg(pctl, data->hwirq, REG_GPIOx_GRP,
303 			   FIELD_PREP(REG_GPIOx_GRP, 0));
304 
305 	apple_gpio_direction_input(chip, data->hwirq);
306 	apple_gpio_irq_unmask(data);
307 
308 	return 0;
309 }
310 
311 static int apple_gpio_irq_set_type(struct irq_data *data,
312 					unsigned int type)
313 {
314 	struct apple_gpio_pinctrl *pctl =
315 		gpiochip_get_data(irq_data_get_irq_chip_data(data));
316 	int irqtype = apple_gpio_irq_type(type);
317 
318 	if (irqtype < 0)
319 		return irqtype;
320 
321 	apple_gpio_set_reg(pctl, data->hwirq, REG_GPIOx_MODE,
322 			   FIELD_PREP(REG_GPIOx_MODE, irqtype));
323 
324 	if (type & IRQ_TYPE_LEVEL_MASK)
325 		irq_set_handler_locked(data, handle_level_irq);
326 	else
327 		irq_set_handler_locked(data, handle_edge_irq);
328 	return 0;
329 }
330 
331 static void apple_gpio_irq_handler(struct irq_desc *desc)
332 {
333 	struct irq_chip *chip = irq_desc_get_chip(desc);
334 	u8 *grpp = irq_desc_get_handler_data(desc);
335 	struct apple_gpio_pinctrl *pctl;
336 	unsigned int pinh, pinl;
337 	unsigned long pending;
338 	struct gpio_chip *gc;
339 
340 	pctl = container_of(grpp - *grpp, typeof(*pctl), irqgrps[0]);
341 	gc = &pctl->gpio_chip;
342 
343 	chained_irq_enter(chip, desc);
344 	for (pinh = 0; pinh < gc->ngpio; pinh += 32) {
345 		pending = readl_relaxed(pctl->base + REG_IRQ(*grpp, pinh));
346 		for_each_set_bit(pinl, &pending, 32)
347 			generic_handle_domain_irq(gc->irq.domain, pinh + pinl);
348 	}
349 	chained_irq_exit(chip, desc);
350 }
351 
352 static struct irq_chip apple_gpio_irqchip = {
353 	.name		= "Apple-GPIO",
354 	.irq_startup	= apple_gpio_irq_startup,
355 	.irq_ack	= apple_gpio_irq_ack,
356 	.irq_mask	= apple_gpio_irq_mask,
357 	.irq_unmask	= apple_gpio_irq_unmask,
358 	.irq_set_type	= apple_gpio_irq_set_type,
359 };
360 
361 /* Probe & register */
362 
363 static int apple_gpio_register(struct apple_gpio_pinctrl *pctl)
364 {
365 	struct gpio_irq_chip *girq = &pctl->gpio_chip.irq;
366 	void **irq_data = NULL;
367 	int ret;
368 
369 	if (!of_property_read_bool(pctl->dev->of_node, "gpio-controller"))
370 		return dev_err_probe(pctl->dev,	-ENODEV,
371 				     "No gpio-controller property\n");
372 
373 	pctl->irq_chip = apple_gpio_irqchip;
374 
375 	pctl->gpio_chip.label = dev_name(pctl->dev);
376 	pctl->gpio_chip.request = gpiochip_generic_request;
377 	pctl->gpio_chip.free = gpiochip_generic_free;
378 	pctl->gpio_chip.get_direction = apple_gpio_get_direction;
379 	pctl->gpio_chip.direction_input = apple_gpio_direction_input;
380 	pctl->gpio_chip.direction_output = apple_gpio_direction_output;
381 	pctl->gpio_chip.get = apple_gpio_get;
382 	pctl->gpio_chip.set = apple_gpio_set;
383 	pctl->gpio_chip.base = -1;
384 	pctl->gpio_chip.ngpio = pctl->pinctrl_desc.npins;
385 	pctl->gpio_chip.parent = pctl->dev;
386 	pctl->gpio_chip.of_node = pctl->dev->of_node;
387 
388 	if (girq->num_parents) {
389 		int i;
390 
391 		girq->chip = &pctl->irq_chip;
392 		girq->parent_handler = apple_gpio_irq_handler;
393 
394 		girq->parents = kmalloc_array(girq->num_parents,
395 					      sizeof(*girq->parents),
396 					      GFP_KERNEL);
397 		irq_data = kmalloc_array(girq->num_parents, sizeof(*irq_data),
398 					 GFP_KERNEL);
399 		if (!girq->parents || !irq_data) {
400 			ret = -ENOMEM;
401 			goto out;
402 		}
403 
404 		for (i = 0; i < girq->num_parents; i++) {
405 			ret = platform_get_irq(to_platform_device(pctl->dev),
406 					       i);
407 			if (ret < 0)
408 				goto out;
409 
410 			girq->parents[i] = ret;
411 			pctl->irqgrps[i] = i;
412 			irq_data[i] = &pctl->irqgrps[i];
413 		}
414 
415 		girq->parent_handler_data_array = irq_data;
416 		girq->per_parent_data = true;
417 		girq->default_type = IRQ_TYPE_NONE;
418 		girq->handler = handle_level_irq;
419 	}
420 
421 	ret = devm_gpiochip_add_data(pctl->dev, &pctl->gpio_chip, pctl);
422 out:
423 	kfree(girq->parents);
424 	kfree(irq_data);
425 
426 	return ret;
427 }
428 
429 static int apple_gpio_pinctrl_probe(struct platform_device *pdev)
430 {
431 	struct apple_gpio_pinctrl *pctl;
432 	struct pinctrl_pin_desc *pins;
433 	unsigned int npins;
434 	const char **pin_names;
435 	unsigned int *pin_nums;
436 	static const char* pinmux_functions[] = {
437 		"gpio", "periph1", "periph2", "periph3"
438 	};
439 	unsigned int i, nirqs = 0;
440 	int res;
441 
442 	if (of_property_read_bool(pdev->dev.of_node, "interrupt-controller")) {
443 		res = platform_irq_count(pdev);
444 		if (res > 0)
445 			nirqs = res;
446 	}
447 
448 	pctl = devm_kzalloc(&pdev->dev, struct_size(pctl, irqgrps, nirqs),
449 			    GFP_KERNEL);
450 	if (!pctl)
451 		return -ENOMEM;
452 	pctl->dev = &pdev->dev;
453 	pctl->gpio_chip.irq.num_parents = nirqs;
454 	dev_set_drvdata(&pdev->dev, pctl);
455 
456 	if (of_property_read_u32(pdev->dev.of_node, "apple,npins", &npins))
457 		return dev_err_probe(&pdev->dev, -EINVAL,
458 				     "apple,npins property not found\n");
459 
460 	pins = devm_kmalloc_array(&pdev->dev, npins, sizeof(pins[0]),
461 				  GFP_KERNEL);
462 	pin_names = devm_kmalloc_array(&pdev->dev, npins, sizeof(pin_names[0]),
463 				       GFP_KERNEL);
464 	pin_nums = devm_kmalloc_array(&pdev->dev, npins, sizeof(pin_nums[0]),
465 				      GFP_KERNEL);
466 	if (!pins || !pin_names || !pin_nums)
467 		return -ENOMEM;
468 
469 	pctl->base = devm_platform_ioremap_resource(pdev, 0);
470 	if (IS_ERR(pctl->base))
471 		return PTR_ERR(pctl->base);
472 
473 	pctl->map = devm_regmap_init_mmio(&pdev->dev, pctl->base, &regmap_config);
474 	if (IS_ERR(pctl->map))
475 		return dev_err_probe(&pdev->dev, PTR_ERR(pctl->map),
476 				     "Failed to create regmap\n");
477 
478 	for (i = 0; i < npins; i++) {
479 		pins[i].number = i;
480 		pins[i].name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "PIN%u", i);
481 		pins[i].drv_data = pctl;
482 		pin_names[i] = pins[i].name;
483 		pin_nums[i] = i;
484 	}
485 
486 	pctl->pinctrl_desc.name = dev_name(pctl->dev);
487 	pctl->pinctrl_desc.pins = pins;
488 	pctl->pinctrl_desc.npins = npins;
489 	pctl->pinctrl_desc.pctlops = &apple_gpio_pinctrl_ops;
490 	pctl->pinctrl_desc.pmxops = &apple_gpio_pinmux_ops;
491 
492 	pctl->pctldev =	devm_pinctrl_register(&pdev->dev, &pctl->pinctrl_desc, pctl);
493 	if (IS_ERR(pctl->pctldev))
494 		return dev_err_probe(&pdev->dev, PTR_ERR(pctl->pctldev),
495 				     "Failed to register pinctrl device.\n");
496 
497 	for (i = 0; i < npins; i++) {
498 		res = pinctrl_generic_add_group(pctl->pctldev, pins[i].name,
499 						pin_nums + i, 1, pctl);
500 		if (res < 0)
501 			return dev_err_probe(pctl->dev, res,
502 					     "Failed to register group");
503 	}
504 
505 	for (i = 0; i < ARRAY_SIZE(pinmux_functions); ++i) {
506 		res = pinmux_generic_add_function(pctl->pctldev, pinmux_functions[i],
507 						  pin_names, npins, pctl);
508 		if (res < 0)
509 			return dev_err_probe(pctl->dev, res,
510 					     "Failed to register function.");
511 	}
512 
513 	return apple_gpio_register(pctl);
514 }
515 
516 static const struct of_device_id apple_gpio_pinctrl_of_match[] = {
517 	{ .compatible = "apple,pinctrl", },
518 	{ }
519 };
520 
521 static struct platform_driver apple_gpio_pinctrl_driver = {
522 	.driver = {
523 		.name = "apple-gpio-pinctrl",
524 		.of_match_table = apple_gpio_pinctrl_of_match,
525 		.suppress_bind_attrs = true,
526 	},
527 	.probe = apple_gpio_pinctrl_probe,
528 };
529 module_platform_driver(apple_gpio_pinctrl_driver);
530 
531 MODULE_DESCRIPTION("Apple pinctrl/GPIO driver");
532 MODULE_AUTHOR("Stan Skowronek <stan@corellium.com>");
533 MODULE_AUTHOR("Joey Gouly <joey.gouly@arm.com>");
534 MODULE_LICENSE("GPL v2");
535