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