xref: /linux/drivers/gpio/gpio-wcove.c (revision 447e140e66fd226350b3ce86cffc965eaae4c856)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Intel Whiskey Cove PMIC GPIO Driver
4  *
5  * This driver is written based on gpio-crystalcove.c
6  *
7  * Copyright (C) 2016 Intel Corporation. All rights reserved.
8  */
9 
10 #include <linux/bitops.h>
11 #include <linux/gpio/driver.h>
12 #include <linux/interrupt.h>
13 #include <linux/mfd/intel_soc_pmic.h>
14 #include <linux/module.h>
15 #include <linux/platform_device.h>
16 #include <linux/regmap.h>
17 #include <linux/seq_file.h>
18 
19 /*
20  * Whiskey Cove PMIC has 13 physical GPIO pins divided into 3 banks:
21  * Bank 0: Pin  0 - 6
22  * Bank 1: Pin  7 - 10
23  * Bank 2: Pin 11 - 12
24  * Each pin has one output control register and one input control register.
25  */
26 #define BANK0_NR_PINS		7
27 #define BANK1_NR_PINS		4
28 #define BANK2_NR_PINS		2
29 #define WCOVE_GPIO_NUM		(BANK0_NR_PINS + BANK1_NR_PINS + BANK2_NR_PINS)
30 #define WCOVE_VGPIO_NUM		94
31 /* GPIO output control registers (one per pin): 0x4e44 - 0x4e50 */
32 #define GPIO_OUT_CTRL_BASE	0x4e44
33 /* GPIO input control registers (one per pin): 0x4e51 - 0x4e5d */
34 #define GPIO_IN_CTRL_BASE	0x4e51
35 
36 /*
37  * GPIO interrupts are organized in two groups:
38  * Group 0: Bank 0 pins (Pin 0 - 6)
39  * Group 1: Bank 1 and Bank 2 pins (Pin 7 - 12)
40  * Each group has two registers (one bit per pin): status and mask.
41  */
42 #define GROUP0_NR_IRQS		7
43 #define GROUP1_NR_IRQS		6
44 #define IRQ_MASK_BASE		0x4e19
45 #define IRQ_STATUS_BASE		0x4e0b
46 #define GPIO_IRQ0_MASK		GENMASK(6, 0)
47 #define GPIO_IRQ1_MASK		GENMASK(5, 0)
48 #define UPDATE_IRQ_TYPE		BIT(0)
49 #define UPDATE_IRQ_MASK		BIT(1)
50 
51 #define CTLI_INTCNT_DIS		(0 << 1)
52 #define CTLI_INTCNT_NE		(1 << 1)
53 #define CTLI_INTCNT_PE		(2 << 1)
54 #define CTLI_INTCNT_BE		(3 << 1)
55 
56 #define CTLO_DIR_IN		(0 << 5)
57 #define CTLO_DIR_OUT		(1 << 5)
58 
59 #define CTLO_DRV_MASK		(1 << 4)
60 #define CTLO_DRV_OD		(0 << 4)
61 #define CTLO_DRV_CMOS		(1 << 4)
62 
63 #define CTLO_DRV_REN		(1 << 3)
64 
65 #define CTLO_RVAL_2KDOWN	(0 << 1)
66 #define CTLO_RVAL_2KUP		(1 << 1)
67 #define CTLO_RVAL_50KDOWN	(2 << 1)
68 #define CTLO_RVAL_50KUP		(3 << 1)
69 
70 #define CTLO_INPUT_SET		(CTLO_DRV_CMOS | CTLO_DRV_REN | CTLO_RVAL_2KUP)
71 #define CTLO_OUTPUT_SET		(CTLO_DIR_OUT | CTLO_INPUT_SET)
72 
73 enum ctrl_register {
74 	CTRL_IN,
75 	CTRL_OUT,
76 	IRQ_STATUS,
77 	IRQ_MASK,
78 };
79 
80 /*
81  * struct wcove_gpio - Whiskey Cove GPIO controller
82  * @buslock: for bus lock/sync and unlock.
83  * @chip: the abstract gpio_chip structure.
84  * @dev: the gpio device
85  * @regmap: the regmap from the parent device.
86  * @regmap_irq_chip: the regmap of the gpio irq chip.
87  * @update: pending IRQ setting update, to be written to the chip upon unlock.
88  * @intcnt: the Interrupt Detect value to be written.
89  * @set_irq_mask: true if the IRQ mask needs to be set, false to clear.
90  */
91 struct wcove_gpio {
92 	struct mutex buslock;
93 	struct gpio_chip chip;
94 	struct device *dev;
95 	struct regmap *regmap;
96 	struct regmap_irq_chip_data *regmap_irq_chip;
97 	int update;
98 	int intcnt;
99 	bool set_irq_mask;
100 };
101 
102 static inline int to_reg(int gpio, enum ctrl_register type)
103 {
104 	unsigned int reg = type == CTRL_IN ? GPIO_IN_CTRL_BASE : GPIO_OUT_CTRL_BASE;
105 
106 	if (gpio >= WCOVE_GPIO_NUM)
107 		return -ENOTSUPP;
108 
109 	return reg + gpio;
110 }
111 
112 static inline int to_ireg(int gpio, enum ctrl_register type, unsigned int *mask)
113 {
114 	unsigned int reg = type == IRQ_STATUS ? IRQ_STATUS_BASE : IRQ_MASK_BASE;
115 
116 	if (gpio < GROUP0_NR_IRQS) {
117 		reg += 0;
118 		*mask = BIT(gpio);
119 	} else {
120 		reg += 1;
121 		*mask = BIT(gpio - GROUP0_NR_IRQS);
122 	}
123 
124 	return reg;
125 }
126 
127 static void wcove_update_irq_mask(struct wcove_gpio *wg, irq_hw_number_t gpio)
128 {
129 	unsigned int mask, reg = to_ireg(gpio, IRQ_MASK, &mask);
130 
131 	if (wg->set_irq_mask)
132 		regmap_set_bits(wg->regmap, reg, mask);
133 	else
134 		regmap_clear_bits(wg->regmap, reg, mask);
135 }
136 
137 static void wcove_update_irq_ctrl(struct wcove_gpio *wg, irq_hw_number_t gpio)
138 {
139 	int reg = to_reg(gpio, CTRL_IN);
140 
141 	regmap_update_bits(wg->regmap, reg, CTLI_INTCNT_BE, wg->intcnt);
142 }
143 
144 static int wcove_gpio_dir_in(struct gpio_chip *chip, unsigned int gpio)
145 {
146 	struct wcove_gpio *wg = gpiochip_get_data(chip);
147 	int reg = to_reg(gpio, CTRL_OUT);
148 
149 	if (reg < 0)
150 		return 0;
151 
152 	return regmap_write(wg->regmap, reg, CTLO_INPUT_SET);
153 }
154 
155 static int wcove_gpio_dir_out(struct gpio_chip *chip, unsigned int gpio,
156 				    int value)
157 {
158 	struct wcove_gpio *wg = gpiochip_get_data(chip);
159 	int reg = to_reg(gpio, CTRL_OUT);
160 
161 	if (reg < 0)
162 		return 0;
163 
164 	return regmap_write(wg->regmap, reg, CTLO_OUTPUT_SET | value);
165 }
166 
167 static int wcove_gpio_get_direction(struct gpio_chip *chip, unsigned int gpio)
168 {
169 	struct wcove_gpio *wg = gpiochip_get_data(chip);
170 	unsigned int val;
171 	int ret, reg = to_reg(gpio, CTRL_OUT);
172 
173 	if (reg < 0)
174 		return GPIO_LINE_DIRECTION_OUT;
175 
176 	ret = regmap_read(wg->regmap, reg, &val);
177 	if (ret)
178 		return ret;
179 
180 	if (val & CTLO_DIR_OUT)
181 		return GPIO_LINE_DIRECTION_OUT;
182 
183 	return GPIO_LINE_DIRECTION_IN;
184 }
185 
186 static int wcove_gpio_get(struct gpio_chip *chip, unsigned int gpio)
187 {
188 	struct wcove_gpio *wg = gpiochip_get_data(chip);
189 	unsigned int val;
190 	int ret, reg = to_reg(gpio, CTRL_IN);
191 
192 	if (reg < 0)
193 		return 0;
194 
195 	ret = regmap_read(wg->regmap, reg, &val);
196 	if (ret)
197 		return ret;
198 
199 	return val & 0x1;
200 }
201 
202 static void wcove_gpio_set(struct gpio_chip *chip, unsigned int gpio, int value)
203 {
204 	struct wcove_gpio *wg = gpiochip_get_data(chip);
205 	int reg = to_reg(gpio, CTRL_OUT);
206 
207 	if (reg < 0)
208 		return;
209 
210 	if (value)
211 		regmap_set_bits(wg->regmap, reg, 1);
212 	else
213 		regmap_clear_bits(wg->regmap, reg, 1);
214 }
215 
216 static int wcove_gpio_set_config(struct gpio_chip *chip, unsigned int gpio,
217 				 unsigned long config)
218 {
219 	struct wcove_gpio *wg = gpiochip_get_data(chip);
220 	int reg = to_reg(gpio, CTRL_OUT);
221 
222 	if (reg < 0)
223 		return 0;
224 
225 	switch (pinconf_to_config_param(config)) {
226 	case PIN_CONFIG_DRIVE_OPEN_DRAIN:
227 		return regmap_update_bits(wg->regmap, reg, CTLO_DRV_MASK,
228 					  CTLO_DRV_OD);
229 	case PIN_CONFIG_DRIVE_PUSH_PULL:
230 		return regmap_update_bits(wg->regmap, reg, CTLO_DRV_MASK,
231 					  CTLO_DRV_CMOS);
232 	default:
233 		break;
234 	}
235 
236 	return -ENOTSUPP;
237 }
238 
239 static int wcove_irq_type(struct irq_data *data, unsigned int type)
240 {
241 	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
242 	struct wcove_gpio *wg = gpiochip_get_data(chip);
243 	irq_hw_number_t gpio = irqd_to_hwirq(data);
244 
245 	if (gpio >= WCOVE_GPIO_NUM)
246 		return 0;
247 
248 	switch (type) {
249 	case IRQ_TYPE_NONE:
250 		wg->intcnt = CTLI_INTCNT_DIS;
251 		break;
252 	case IRQ_TYPE_EDGE_BOTH:
253 		wg->intcnt = CTLI_INTCNT_BE;
254 		break;
255 	case IRQ_TYPE_EDGE_RISING:
256 		wg->intcnt = CTLI_INTCNT_PE;
257 		break;
258 	case IRQ_TYPE_EDGE_FALLING:
259 		wg->intcnt = CTLI_INTCNT_NE;
260 		break;
261 	default:
262 		return -EINVAL;
263 	}
264 
265 	wg->update |= UPDATE_IRQ_TYPE;
266 
267 	return 0;
268 }
269 
270 static void wcove_bus_lock(struct irq_data *data)
271 {
272 	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
273 	struct wcove_gpio *wg = gpiochip_get_data(chip);
274 
275 	mutex_lock(&wg->buslock);
276 }
277 
278 static void wcove_bus_sync_unlock(struct irq_data *data)
279 {
280 	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
281 	struct wcove_gpio *wg = gpiochip_get_data(chip);
282 	irq_hw_number_t gpio = irqd_to_hwirq(data);
283 
284 	if (wg->update & UPDATE_IRQ_TYPE)
285 		wcove_update_irq_ctrl(wg, gpio);
286 	if (wg->update & UPDATE_IRQ_MASK)
287 		wcove_update_irq_mask(wg, gpio);
288 	wg->update = 0;
289 
290 	mutex_unlock(&wg->buslock);
291 }
292 
293 static void wcove_irq_unmask(struct irq_data *data)
294 {
295 	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
296 	struct wcove_gpio *wg = gpiochip_get_data(chip);
297 	irq_hw_number_t gpio = irqd_to_hwirq(data);
298 
299 	if (gpio >= WCOVE_GPIO_NUM)
300 		return;
301 
302 	gpiochip_enable_irq(chip, gpio);
303 
304 	wg->set_irq_mask = false;
305 	wg->update |= UPDATE_IRQ_MASK;
306 }
307 
308 static void wcove_irq_mask(struct irq_data *data)
309 {
310 	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
311 	struct wcove_gpio *wg = gpiochip_get_data(chip);
312 	irq_hw_number_t gpio = irqd_to_hwirq(data);
313 
314 	if (gpio >= WCOVE_GPIO_NUM)
315 		return;
316 
317 	wg->set_irq_mask = true;
318 	wg->update |= UPDATE_IRQ_MASK;
319 
320 	gpiochip_disable_irq(chip, gpio);
321 }
322 
323 static const struct irq_chip wcove_irqchip = {
324 	.name			= "Whiskey Cove",
325 	.irq_mask		= wcove_irq_mask,
326 	.irq_unmask		= wcove_irq_unmask,
327 	.irq_set_type		= wcove_irq_type,
328 	.irq_bus_lock		= wcove_bus_lock,
329 	.irq_bus_sync_unlock	= wcove_bus_sync_unlock,
330 	.flags			= IRQCHIP_IMMUTABLE,
331 	GPIOCHIP_IRQ_RESOURCE_HELPERS,
332 };
333 
334 static irqreturn_t wcove_gpio_irq_handler(int irq, void *data)
335 {
336 	struct wcove_gpio *wg = (struct wcove_gpio *)data;
337 	unsigned int virq, gpio;
338 	unsigned long pending;
339 	u8 p[2];
340 
341 	if (regmap_bulk_read(wg->regmap, IRQ_STATUS_BASE, p, 2)) {
342 		dev_err(wg->dev, "Failed to read irq status register\n");
343 		return IRQ_NONE;
344 	}
345 
346 	pending = (p[0] & GPIO_IRQ0_MASK) | ((p[1] & GPIO_IRQ1_MASK) << 7);
347 	if (!pending)
348 		return IRQ_NONE;
349 
350 	/* Iterate until no interrupt is pending */
351 	while (pending) {
352 		/* One iteration is for all pending bits */
353 		for_each_set_bit(gpio, &pending, WCOVE_GPIO_NUM) {
354 			unsigned int mask, reg = to_ireg(gpio, IRQ_STATUS, &mask);
355 
356 			virq = irq_find_mapping(wg->chip.irq.domain, gpio);
357 			handle_nested_irq(virq);
358 			regmap_set_bits(wg->regmap, reg, mask);
359 		}
360 
361 		/* Next iteration */
362 		if (regmap_bulk_read(wg->regmap, IRQ_STATUS_BASE, p, 2)) {
363 			dev_err(wg->dev, "Failed to read irq status\n");
364 			break;
365 		}
366 
367 		pending = (p[0] & GPIO_IRQ0_MASK) | ((p[1] & GPIO_IRQ1_MASK) << 7);
368 	}
369 
370 	return IRQ_HANDLED;
371 }
372 
373 static void wcove_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
374 {
375 	unsigned int ctlo, ctli, irq_mask, irq_status;
376 	struct wcove_gpio *wg = gpiochip_get_data(chip);
377 	int gpio, mask, ret = 0;
378 
379 	for (gpio = 0; gpio < WCOVE_GPIO_NUM; gpio++) {
380 		ret += regmap_read(wg->regmap, to_reg(gpio, CTRL_OUT), &ctlo);
381 		ret += regmap_read(wg->regmap, to_reg(gpio, CTRL_IN), &ctli);
382 		if (ret) {
383 			dev_err(wg->dev, "Failed to read registers: CTRL out/in\n");
384 			break;
385 		}
386 
387 		ret += regmap_read(wg->regmap, to_ireg(gpio, IRQ_MASK, &mask), &irq_mask);
388 		ret += regmap_read(wg->regmap, to_ireg(gpio, IRQ_STATUS, &mask), &irq_status);
389 		if (ret) {
390 			dev_err(wg->dev, "Failed to read registers: IRQ status/mask\n");
391 			break;
392 		}
393 
394 		seq_printf(s, " gpio-%-2d %s %s %s %s ctlo=%2x,%s %s\n",
395 			   gpio, ctlo & CTLO_DIR_OUT ? "out" : "in ",
396 			   ctli & 0x1 ? "hi" : "lo",
397 			   ctli & CTLI_INTCNT_NE ? "fall" : "    ",
398 			   ctli & CTLI_INTCNT_PE ? "rise" : "    ",
399 			   ctlo,
400 			   irq_mask & mask ? "mask  " : "unmask",
401 			   irq_status & mask ? "pending" : "       ");
402 	}
403 }
404 
405 static int wcove_gpio_probe(struct platform_device *pdev)
406 {
407 	struct intel_soc_pmic *pmic;
408 	struct wcove_gpio *wg;
409 	int virq, ret, irq;
410 	struct device *dev;
411 	struct gpio_irq_chip *girq;
412 
413 	/*
414 	 * This gpio platform device is created by a mfd device (see
415 	 * drivers/mfd/intel_soc_pmic_bxtwc.c for details). Information
416 	 * shared by all sub-devices created by the mfd device, the regmap
417 	 * pointer for instance, is stored as driver data of the mfd device
418 	 * driver.
419 	 */
420 	pmic = dev_get_drvdata(pdev->dev.parent);
421 	if (!pmic)
422 		return -ENODEV;
423 
424 	irq = platform_get_irq(pdev, 0);
425 	if (irq < 0)
426 		return irq;
427 
428 	dev = &pdev->dev;
429 
430 	wg = devm_kzalloc(dev, sizeof(*wg), GFP_KERNEL);
431 	if (!wg)
432 		return -ENOMEM;
433 
434 	wg->regmap_irq_chip = pmic->irq_chip_data;
435 
436 	platform_set_drvdata(pdev, wg);
437 
438 	mutex_init(&wg->buslock);
439 	wg->chip.label = KBUILD_MODNAME;
440 	wg->chip.direction_input = wcove_gpio_dir_in;
441 	wg->chip.direction_output = wcove_gpio_dir_out;
442 	wg->chip.get_direction = wcove_gpio_get_direction;
443 	wg->chip.get = wcove_gpio_get;
444 	wg->chip.set = wcove_gpio_set;
445 	wg->chip.set_config = wcove_gpio_set_config;
446 	wg->chip.base = -1;
447 	wg->chip.ngpio = WCOVE_VGPIO_NUM;
448 	wg->chip.can_sleep = true;
449 	wg->chip.parent = pdev->dev.parent;
450 	wg->chip.dbg_show = wcove_gpio_dbg_show;
451 	wg->dev = dev;
452 	wg->regmap = pmic->regmap;
453 
454 	virq = regmap_irq_get_virq(wg->regmap_irq_chip, irq);
455 	if (virq < 0) {
456 		dev_err(dev, "Failed to get virq by irq %d\n", irq);
457 		return virq;
458 	}
459 
460 	girq = &wg->chip.irq;
461 	gpio_irq_chip_set_chip(girq, &wcove_irqchip);
462 	/* This will let us handle the parent IRQ in the driver */
463 	girq->parent_handler = NULL;
464 	girq->num_parents = 0;
465 	girq->parents = NULL;
466 	girq->default_type = IRQ_TYPE_NONE;
467 	girq->handler = handle_simple_irq;
468 	girq->threaded = true;
469 
470 	ret = devm_request_threaded_irq(dev, virq, NULL, wcove_gpio_irq_handler,
471 					IRQF_ONESHOT, pdev->name, wg);
472 	if (ret) {
473 		dev_err(dev, "Failed to request irq %d\n", virq);
474 		return ret;
475 	}
476 
477 	ret = devm_gpiochip_add_data(dev, &wg->chip, wg);
478 	if (ret) {
479 		dev_err(dev, "Failed to add gpiochip: %d\n", ret);
480 		return ret;
481 	}
482 
483 	/* Enable GPIO0 interrupts */
484 	ret = regmap_clear_bits(wg->regmap, IRQ_MASK_BASE + 0, GPIO_IRQ0_MASK);
485 	if (ret)
486 		return ret;
487 
488 	/* Enable GPIO1 interrupts */
489 	ret = regmap_clear_bits(wg->regmap, IRQ_MASK_BASE + 1, GPIO_IRQ1_MASK);
490 	if (ret)
491 		return ret;
492 
493 	return 0;
494 }
495 
496 /*
497  * Whiskey Cove PMIC itself is a analog device(but with digital control
498  * interface) providing power management support for other devices in
499  * the accompanied SoC, so we have no .pm for Whiskey Cove GPIO driver.
500  */
501 static struct platform_driver wcove_gpio_driver = {
502 	.driver = {
503 		.name = "bxt_wcove_gpio",
504 	},
505 	.probe = wcove_gpio_probe,
506 };
507 
508 module_platform_driver(wcove_gpio_driver);
509 
510 MODULE_AUTHOR("Ajay Thomas <ajay.thomas.david.rajamanickam@intel.com>");
511 MODULE_AUTHOR("Bin Gao <bin.gao@intel.com>");
512 MODULE_DESCRIPTION("Intel Whiskey Cove GPIO Driver");
513 MODULE_LICENSE("GPL v2");
514 MODULE_ALIAS("platform:bxt_wcove_gpio");
515