xref: /linux/drivers/pinctrl/pinctrl-apple-gpio.c (revision ca220141fa8ebae09765a242076b2b77338106b0)
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 static const 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 int *num_maps)
106 {
107 	unsigned int 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 bool apple_gpio_pinmux_func_is_gpio(struct pinctrl_dev *pctldev,
174 					   unsigned int selector)
175 {
176 	/* Function selector 0 is always the GPIO mode */
177 	return (selector == 0);
178 }
179 
180 static int apple_gpio_pinmux_set(struct pinctrl_dev *pctldev, unsigned int func,
181 				 unsigned int group)
182 {
183 	struct apple_gpio_pinctrl *pctl = pinctrl_dev_get_drvdata(pctldev);
184 
185 	apple_gpio_set_reg(
186 		pctl, group, REG_GPIOx_PERIPH | REG_GPIOx_INPUT_ENABLE,
187 		FIELD_PREP(REG_GPIOx_PERIPH, func) | REG_GPIOx_INPUT_ENABLE);
188 
189 	return 0;
190 }
191 
192 static const struct pinmux_ops apple_gpio_pinmux_ops = {
193 	.get_functions_count = pinmux_generic_get_function_count,
194 	.get_function_name = pinmux_generic_get_function_name,
195 	.get_function_groups = pinmux_generic_get_function_groups,
196 	.function_is_gpio = apple_gpio_pinmux_func_is_gpio,
197 	.set_mux = apple_gpio_pinmux_set,
198 	.strict = true,
199 };
200 
201 /* GPIO chip functions */
202 
203 static int apple_gpio_get_direction(struct gpio_chip *chip, unsigned int offset)
204 {
205 	struct apple_gpio_pinctrl *pctl = gpiochip_get_data(chip);
206 	unsigned int reg = apple_gpio_get_reg(pctl, offset);
207 
208 	if (FIELD_GET(REG_GPIOx_MODE, reg) == REG_GPIOx_OUT)
209 		return GPIO_LINE_DIRECTION_OUT;
210 	return GPIO_LINE_DIRECTION_IN;
211 }
212 
213 static int apple_gpio_get(struct gpio_chip *chip, unsigned int offset)
214 {
215 	struct apple_gpio_pinctrl *pctl = gpiochip_get_data(chip);
216 	unsigned int reg = apple_gpio_get_reg(pctl, offset);
217 
218 	/*
219 	 * If this is an input GPIO, read the actual value (not the
220 	 * cached regmap value)
221 	 */
222 	if (FIELD_GET(REG_GPIOx_MODE, reg) != REG_GPIOx_OUT)
223 		reg = readl_relaxed(pctl->base + REG_GPIO(offset));
224 
225 	return !!(reg & REG_GPIOx_DATA);
226 }
227 
228 static int apple_gpio_set(struct gpio_chip *chip, unsigned int offset, int value)
229 {
230 	struct apple_gpio_pinctrl *pctl = gpiochip_get_data(chip);
231 
232 	apple_gpio_set_reg(pctl, offset, REG_GPIOx_DATA, value ? REG_GPIOx_DATA : 0);
233 
234 	return 0;
235 }
236 
237 static int apple_gpio_direction_input(struct gpio_chip *chip, unsigned int offset)
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 				   REG_GPIOx_INPUT_ENABLE,
244 			   FIELD_PREP(REG_GPIOx_MODE, REG_GPIOx_IN_IRQ_OFF) |
245 				   REG_GPIOx_INPUT_ENABLE);
246 	return 0;
247 }
248 
249 static int apple_gpio_direction_output(struct gpio_chip *chip,
250 				       unsigned int offset, int value)
251 {
252 	struct apple_gpio_pinctrl *pctl = gpiochip_get_data(chip);
253 
254 	apple_gpio_set_reg(pctl, offset,
255 			   REG_GPIOx_PERIPH | REG_GPIOx_MODE | REG_GPIOx_DATA,
256 			   FIELD_PREP(REG_GPIOx_MODE, REG_GPIOx_OUT) |
257 				   (value ? REG_GPIOx_DATA : 0));
258 	return 0;
259 }
260 
261 /* IRQ chip functions */
262 
263 static void apple_gpio_irq_ack(struct irq_data *data)
264 {
265 	struct apple_gpio_pinctrl *pctl = gpiochip_get_data(irq_data_get_irq_chip_data(data));
266 	unsigned int irqgrp = FIELD_GET(REG_GPIOx_GRP, apple_gpio_get_reg(pctl, data->hwirq));
267 
268 	writel(BIT(data->hwirq % 32), pctl->base + REG_IRQ(irqgrp, data->hwirq));
269 }
270 
271 static unsigned int apple_gpio_irq_type(unsigned int type)
272 {
273 	switch (type & IRQ_TYPE_SENSE_MASK) {
274 	case IRQ_TYPE_EDGE_RISING:
275 		return REG_GPIOx_IN_IRQ_UP;
276 	case IRQ_TYPE_EDGE_FALLING:
277 		return REG_GPIOx_IN_IRQ_DN;
278 	case IRQ_TYPE_EDGE_BOTH:
279 		return REG_GPIOx_IN_IRQ_ANY;
280 	case IRQ_TYPE_LEVEL_HIGH:
281 		return REG_GPIOx_IN_IRQ_HI;
282 	case IRQ_TYPE_LEVEL_LOW:
283 		return REG_GPIOx_IN_IRQ_LO;
284 	default:
285 		return REG_GPIOx_IN_IRQ_OFF;
286 	}
287 }
288 
289 static void apple_gpio_irq_mask(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 
294 	apple_gpio_set_reg(pctl, data->hwirq, REG_GPIOx_MODE,
295 			   FIELD_PREP(REG_GPIOx_MODE, REG_GPIOx_IN_IRQ_OFF));
296 	gpiochip_disable_irq(gc, data->hwirq);
297 }
298 
299 static void apple_gpio_irq_unmask(struct irq_data *data)
300 {
301 	struct gpio_chip *gc = irq_data_get_irq_chip_data(data);
302 	struct apple_gpio_pinctrl *pctl = gpiochip_get_data(gc);
303 	unsigned int irqtype = apple_gpio_irq_type(irqd_get_trigger_type(data));
304 
305 	gpiochip_enable_irq(gc, data->hwirq);
306 	apple_gpio_set_reg(pctl, data->hwirq, REG_GPIOx_MODE,
307 			   FIELD_PREP(REG_GPIOx_MODE, irqtype));
308 }
309 
310 static unsigned int apple_gpio_irq_startup(struct irq_data *data)
311 {
312 	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
313 	struct apple_gpio_pinctrl *pctl = gpiochip_get_data(chip);
314 
315 	apple_gpio_set_reg(pctl, data->hwirq, REG_GPIOx_GRP,
316 			   FIELD_PREP(REG_GPIOx_GRP, 0));
317 
318 	apple_gpio_direction_input(chip, data->hwirq);
319 	apple_gpio_irq_unmask(data);
320 
321 	return 0;
322 }
323 
324 static int apple_gpio_irq_set_type(struct irq_data *data, unsigned int type)
325 {
326 	struct apple_gpio_pinctrl *pctl = gpiochip_get_data(irq_data_get_irq_chip_data(data));
327 	unsigned int irqtype = apple_gpio_irq_type(type);
328 
329 	if (irqtype == REG_GPIOx_IN_IRQ_OFF)
330 		return -EINVAL;
331 
332 	apple_gpio_set_reg(pctl, data->hwirq, REG_GPIOx_MODE,
333 			   FIELD_PREP(REG_GPIOx_MODE, irqtype));
334 
335 	if (type & IRQ_TYPE_LEVEL_MASK)
336 		irq_set_handler_locked(data, handle_level_irq);
337 	else
338 		irq_set_handler_locked(data, handle_edge_irq);
339 	return 0;
340 }
341 
342 static void apple_gpio_irq_handler(struct irq_desc *desc)
343 {
344 	struct irq_chip *chip = irq_desc_get_chip(desc);
345 	u8 *grpp = irq_desc_get_handler_data(desc);
346 	struct apple_gpio_pinctrl *pctl;
347 	unsigned int pinh, pinl;
348 	unsigned long pending;
349 	struct gpio_chip *gc;
350 
351 	pctl = container_of(grpp - *grpp, typeof(*pctl), irqgrps[0]);
352 	gc = &pctl->gpio_chip;
353 
354 	chained_irq_enter(chip, desc);
355 	for (pinh = 0; pinh < gc->ngpio; pinh += 32) {
356 		pending = readl_relaxed(pctl->base + REG_IRQ(*grpp, pinh));
357 		for_each_set_bit(pinl, &pending, 32)
358 			generic_handle_domain_irq(gc->irq.domain, pinh + pinl);
359 	}
360 	chained_irq_exit(chip, desc);
361 }
362 
363 static const struct irq_chip apple_gpio_irqchip = {
364 	.name			= "Apple-GPIO",
365 	.irq_startup		= apple_gpio_irq_startup,
366 	.irq_ack		= apple_gpio_irq_ack,
367 	.irq_mask		= apple_gpio_irq_mask,
368 	.irq_unmask		= apple_gpio_irq_unmask,
369 	.irq_set_type		= apple_gpio_irq_set_type,
370 	.flags			= IRQCHIP_IMMUTABLE,
371 	GPIOCHIP_IRQ_RESOURCE_HELPERS,
372 };
373 
374 /* Probe & register */
375 
376 static int apple_gpio_register(struct apple_gpio_pinctrl *pctl)
377 {
378 	struct gpio_irq_chip *girq = &pctl->gpio_chip.irq;
379 	void **irq_data = NULL;
380 	int ret;
381 
382 	pctl->gpio_chip.label = dev_name(pctl->dev);
383 	pctl->gpio_chip.request = gpiochip_generic_request;
384 	pctl->gpio_chip.free = gpiochip_generic_free;
385 	pctl->gpio_chip.get_direction = apple_gpio_get_direction;
386 	pctl->gpio_chip.direction_input = apple_gpio_direction_input;
387 	pctl->gpio_chip.direction_output = apple_gpio_direction_output;
388 	pctl->gpio_chip.get = apple_gpio_get;
389 	pctl->gpio_chip.set = apple_gpio_set;
390 	pctl->gpio_chip.base = -1;
391 	pctl->gpio_chip.ngpio = pctl->pinctrl_desc.npins;
392 	pctl->gpio_chip.parent = pctl->dev;
393 
394 	if (girq->num_parents) {
395 		int i;
396 
397 		gpio_irq_chip_set_chip(girq, &apple_gpio_irqchip);
398 		girq->parent_handler = apple_gpio_irq_handler;
399 
400 		girq->parents = kmalloc_array(girq->num_parents,
401 					      sizeof(*girq->parents),
402 					      GFP_KERNEL);
403 		irq_data = kmalloc_array(girq->num_parents, sizeof(*irq_data),
404 					 GFP_KERNEL);
405 		if (!girq->parents || !irq_data) {
406 			ret = -ENOMEM;
407 			goto out_free_irq_data;
408 		}
409 
410 		for (i = 0; i < girq->num_parents; i++) {
411 			ret = platform_get_irq(to_platform_device(pctl->dev), i);
412 			if (ret < 0)
413 				goto out_free_irq_data;
414 
415 			girq->parents[i] = ret;
416 			pctl->irqgrps[i] = i;
417 			irq_data[i] = &pctl->irqgrps[i];
418 		}
419 
420 		girq->parent_handler_data_array = irq_data;
421 		girq->per_parent_data = true;
422 		girq->default_type = IRQ_TYPE_NONE;
423 		girq->handler = handle_level_irq;
424 	}
425 
426 	ret = devm_gpiochip_add_data(pctl->dev, &pctl->gpio_chip, pctl);
427 
428 out_free_irq_data:
429 	kfree(girq->parents);
430 	kfree(irq_data);
431 
432 	return ret;
433 }
434 
435 static int apple_gpio_pinctrl_probe(struct platform_device *pdev)
436 {
437 	struct apple_gpio_pinctrl *pctl;
438 	struct pinctrl_pin_desc *pins;
439 	unsigned int npins;
440 	const char **pin_names;
441 	unsigned int *pin_nums;
442 	static const char *pinmux_functions[] = {
443 		"gpio", "periph1", "periph2", "periph3"
444 	};
445 	unsigned int i, nirqs = 0;
446 	int res;
447 
448 	if (of_property_read_bool(pdev->dev.of_node, "interrupt-controller")) {
449 		res = platform_irq_count(pdev);
450 		if (res > 0)
451 			nirqs = res;
452 	}
453 
454 	pctl = devm_kzalloc(&pdev->dev, struct_size(pctl, irqgrps, nirqs),
455 			    GFP_KERNEL);
456 	if (!pctl)
457 		return -ENOMEM;
458 	pctl->dev = &pdev->dev;
459 	pctl->gpio_chip.irq.num_parents = nirqs;
460 	dev_set_drvdata(&pdev->dev, pctl);
461 
462 	if (of_property_read_u32(pdev->dev.of_node, "apple,npins", &npins))
463 		return dev_err_probe(&pdev->dev, -EINVAL,
464 				     "apple,npins property not found\n");
465 
466 	pins = devm_kmalloc_array(&pdev->dev, npins, sizeof(pins[0]),
467 				  GFP_KERNEL);
468 	pin_names = devm_kmalloc_array(&pdev->dev, npins, sizeof(pin_names[0]),
469 				       GFP_KERNEL);
470 	pin_nums = devm_kmalloc_array(&pdev->dev, npins, sizeof(pin_nums[0]),
471 				      GFP_KERNEL);
472 	if (!pins || !pin_names || !pin_nums)
473 		return -ENOMEM;
474 
475 	pctl->base = devm_platform_ioremap_resource(pdev, 0);
476 	if (IS_ERR(pctl->base))
477 		return PTR_ERR(pctl->base);
478 
479 	pctl->map = devm_regmap_init_mmio(&pdev->dev, pctl->base, &regmap_config);
480 	if (IS_ERR(pctl->map))
481 		return dev_err_probe(&pdev->dev, PTR_ERR(pctl->map),
482 				     "Failed to create regmap\n");
483 
484 	for (i = 0; i < npins; i++) {
485 		pins[i].number = i;
486 		pins[i].name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "PIN%u", i);
487 		if (!pins[i].name)
488 			return -ENOMEM;
489 
490 		pins[i].drv_data = pctl;
491 		pin_names[i] = pins[i].name;
492 		pin_nums[i] = i;
493 	}
494 
495 	pctl->pinctrl_desc.name = dev_name(pctl->dev);
496 	pctl->pinctrl_desc.pins = pins;
497 	pctl->pinctrl_desc.npins = npins;
498 	pctl->pinctrl_desc.pctlops = &apple_gpio_pinctrl_ops;
499 	pctl->pinctrl_desc.pmxops = &apple_gpio_pinmux_ops;
500 
501 	pctl->pctldev =	devm_pinctrl_register(&pdev->dev, &pctl->pinctrl_desc, pctl);
502 	if (IS_ERR(pctl->pctldev))
503 		return dev_err_probe(&pdev->dev, PTR_ERR(pctl->pctldev),
504 				     "Failed to register pinctrl device.\n");
505 
506 	for (i = 0; i < npins; i++) {
507 		res = pinctrl_generic_add_group(pctl->pctldev, pins[i].name,
508 						pin_nums + i, 1, pctl);
509 		if (res < 0)
510 			return dev_err_probe(pctl->dev, res,
511 					     "Failed to register group");
512 	}
513 
514 	for (i = 0; i < ARRAY_SIZE(pinmux_functions); ++i) {
515 		res = pinmux_generic_add_function(pctl->pctldev, pinmux_functions[i],
516 						  pin_names, npins, pctl);
517 		if (res < 0)
518 			return dev_err_probe(pctl->dev, res,
519 					     "Failed to register function.");
520 	}
521 
522 	return apple_gpio_register(pctl);
523 }
524 
525 static const struct of_device_id apple_gpio_pinctrl_of_match[] = {
526 	{ .compatible = "apple,t8103-pinctrl", },
527 	{ .compatible = "apple,pinctrl", },
528 	{ }
529 };
530 MODULE_DEVICE_TABLE(of, apple_gpio_pinctrl_of_match);
531 
532 static struct platform_driver apple_gpio_pinctrl_driver = {
533 	.driver = {
534 		.name = "apple-gpio-pinctrl",
535 		.of_match_table = apple_gpio_pinctrl_of_match,
536 		.suppress_bind_attrs = true,
537 	},
538 	.probe = apple_gpio_pinctrl_probe,
539 };
540 module_platform_driver(apple_gpio_pinctrl_driver);
541 
542 MODULE_DESCRIPTION("Apple pinctrl/GPIO driver");
543 MODULE_AUTHOR("Stan Skowronek <stan@corellium.com>");
544 MODULE_AUTHOR("Joey Gouly <joey.gouly@arm.com>");
545 MODULE_LICENSE("GPL v2");
546