xref: /linux/drivers/gpio/gpio-wcove.c (revision 3839a7460721b87501134697b7b90c45dcc7825d)
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 };
77 
78 /*
79  * struct wcove_gpio - Whiskey Cove GPIO controller
80  * @buslock: for bus lock/sync and unlock.
81  * @chip: the abstract gpio_chip structure.
82  * @dev: the gpio device
83  * @regmap: the regmap from the parent device.
84  * @regmap_irq_chip: the regmap of the gpio irq chip.
85  * @update: pending IRQ setting update, to be written to the chip upon unlock.
86  * @intcnt: the Interrupt Detect value to be written.
87  * @set_irq_mask: true if the IRQ mask needs to be set, false to clear.
88  */
89 struct wcove_gpio {
90 	struct mutex buslock;
91 	struct gpio_chip chip;
92 	struct device *dev;
93 	struct regmap *regmap;
94 	struct regmap_irq_chip_data *regmap_irq_chip;
95 	int update;
96 	int intcnt;
97 	bool set_irq_mask;
98 };
99 
100 static inline int to_reg(int gpio, enum ctrl_register reg_type)
101 {
102 	unsigned int reg;
103 
104 	if (gpio >= WCOVE_GPIO_NUM)
105 		return -EOPNOTSUPP;
106 
107 	if (reg_type == CTRL_IN)
108 		reg = GPIO_IN_CTRL_BASE + gpio;
109 	else
110 		reg = GPIO_OUT_CTRL_BASE + gpio;
111 
112 	return reg;
113 }
114 
115 static void wcove_update_irq_mask(struct wcove_gpio *wg, int gpio)
116 {
117 	unsigned int reg, mask;
118 
119 	if (gpio < GROUP0_NR_IRQS) {
120 		reg = IRQ_MASK_BASE;
121 		mask = BIT(gpio % GROUP0_NR_IRQS);
122 	} else {
123 		reg = IRQ_MASK_BASE + 1;
124 		mask = BIT((gpio - GROUP0_NR_IRQS) % GROUP1_NR_IRQS);
125 	}
126 
127 	if (wg->set_irq_mask)
128 		regmap_update_bits(wg->regmap, reg, mask, mask);
129 	else
130 		regmap_update_bits(wg->regmap, reg, mask, 0);
131 }
132 
133 static void wcove_update_irq_ctrl(struct wcove_gpio *wg, int gpio)
134 {
135 	int reg = to_reg(gpio, CTRL_IN);
136 
137 	if (reg < 0)
138 		return;
139 
140 	regmap_update_bits(wg->regmap, reg, CTLI_INTCNT_BE, wg->intcnt);
141 }
142 
143 static int wcove_gpio_dir_in(struct gpio_chip *chip, unsigned int gpio)
144 {
145 	struct wcove_gpio *wg = gpiochip_get_data(chip);
146 	int reg = to_reg(gpio, CTRL_OUT);
147 
148 	if (reg < 0)
149 		return 0;
150 
151 	return regmap_write(wg->regmap, reg, CTLO_INPUT_SET);
152 }
153 
154 static int wcove_gpio_dir_out(struct gpio_chip *chip, unsigned int gpio,
155 				    int value)
156 {
157 	struct wcove_gpio *wg = gpiochip_get_data(chip);
158 	int reg = to_reg(gpio, CTRL_OUT);
159 
160 	if (reg < 0)
161 		return 0;
162 
163 	return regmap_write(wg->regmap, reg, CTLO_OUTPUT_SET | value);
164 }
165 
166 static int wcove_gpio_get_direction(struct gpio_chip *chip, unsigned int gpio)
167 {
168 	struct wcove_gpio *wg = gpiochip_get_data(chip);
169 	unsigned int val;
170 	int ret, reg = to_reg(gpio, CTRL_OUT);
171 
172 	if (reg < 0)
173 		return GPIO_LINE_DIRECTION_OUT;
174 
175 	ret = regmap_read(wg->regmap, reg, &val);
176 	if (ret)
177 		return ret;
178 
179 	if (val & CTLO_DIR_OUT)
180 		return GPIO_LINE_DIRECTION_OUT;
181 
182 	return GPIO_LINE_DIRECTION_IN;
183 }
184 
185 static int wcove_gpio_get(struct gpio_chip *chip, unsigned int gpio)
186 {
187 	struct wcove_gpio *wg = gpiochip_get_data(chip);
188 	unsigned int val;
189 	int ret, reg = to_reg(gpio, CTRL_IN);
190 
191 	if (reg < 0)
192 		return 0;
193 
194 	ret = regmap_read(wg->regmap, reg, &val);
195 	if (ret)
196 		return ret;
197 
198 	return val & 0x1;
199 }
200 
201 static void wcove_gpio_set(struct gpio_chip *chip, unsigned int gpio, int value)
202 {
203 	struct wcove_gpio *wg = gpiochip_get_data(chip);
204 	int reg = to_reg(gpio, CTRL_OUT);
205 
206 	if (reg < 0)
207 		return;
208 
209 	if (value)
210 		regmap_update_bits(wg->regmap, reg, 1, 1);
211 	else
212 		regmap_update_bits(wg->regmap, reg, 1, 0);
213 }
214 
215 static int wcove_gpio_set_config(struct gpio_chip *chip, unsigned int gpio,
216 				 unsigned long config)
217 {
218 	struct wcove_gpio *wg = gpiochip_get_data(chip);
219 	int reg = to_reg(gpio, CTRL_OUT);
220 
221 	if (reg < 0)
222 		return 0;
223 
224 	switch (pinconf_to_config_param(config)) {
225 	case PIN_CONFIG_DRIVE_OPEN_DRAIN:
226 		return regmap_update_bits(wg->regmap, reg, CTLO_DRV_MASK,
227 					  CTLO_DRV_OD);
228 	case PIN_CONFIG_DRIVE_PUSH_PULL:
229 		return regmap_update_bits(wg->regmap, reg, CTLO_DRV_MASK,
230 					  CTLO_DRV_CMOS);
231 	default:
232 		break;
233 	}
234 
235 	return -ENOTSUPP;
236 }
237 
238 static int wcove_irq_type(struct irq_data *data, unsigned int type)
239 {
240 	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
241 	struct wcove_gpio *wg = gpiochip_get_data(chip);
242 
243 	if (data->hwirq >= WCOVE_GPIO_NUM)
244 		return 0;
245 
246 	switch (type) {
247 	case IRQ_TYPE_NONE:
248 		wg->intcnt = CTLI_INTCNT_DIS;
249 		break;
250 	case IRQ_TYPE_EDGE_BOTH:
251 		wg->intcnt = CTLI_INTCNT_BE;
252 		break;
253 	case IRQ_TYPE_EDGE_RISING:
254 		wg->intcnt = CTLI_INTCNT_PE;
255 		break;
256 	case IRQ_TYPE_EDGE_FALLING:
257 		wg->intcnt = CTLI_INTCNT_NE;
258 		break;
259 	default:
260 		return -EINVAL;
261 	}
262 
263 	wg->update |= UPDATE_IRQ_TYPE;
264 
265 	return 0;
266 }
267 
268 static void wcove_bus_lock(struct irq_data *data)
269 {
270 	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
271 	struct wcove_gpio *wg = gpiochip_get_data(chip);
272 
273 	mutex_lock(&wg->buslock);
274 }
275 
276 static void wcove_bus_sync_unlock(struct irq_data *data)
277 {
278 	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
279 	struct wcove_gpio *wg = gpiochip_get_data(chip);
280 	int gpio = data->hwirq;
281 
282 	if (wg->update & UPDATE_IRQ_TYPE)
283 		wcove_update_irq_ctrl(wg, gpio);
284 	if (wg->update & UPDATE_IRQ_MASK)
285 		wcove_update_irq_mask(wg, gpio);
286 	wg->update = 0;
287 
288 	mutex_unlock(&wg->buslock);
289 }
290 
291 static void wcove_irq_unmask(struct irq_data *data)
292 {
293 	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
294 	struct wcove_gpio *wg = gpiochip_get_data(chip);
295 
296 	if (data->hwirq >= WCOVE_GPIO_NUM)
297 		return;
298 
299 	wg->set_irq_mask = false;
300 	wg->update |= UPDATE_IRQ_MASK;
301 }
302 
303 static void wcove_irq_mask(struct irq_data *data)
304 {
305 	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
306 	struct wcove_gpio *wg = gpiochip_get_data(chip);
307 
308 	if (data->hwirq >= WCOVE_GPIO_NUM)
309 		return;
310 
311 	wg->set_irq_mask = true;
312 	wg->update |= UPDATE_IRQ_MASK;
313 }
314 
315 static struct irq_chip wcove_irqchip = {
316 	.name			= "Whiskey Cove",
317 	.irq_mask		= wcove_irq_mask,
318 	.irq_unmask		= wcove_irq_unmask,
319 	.irq_set_type		= wcove_irq_type,
320 	.irq_bus_lock		= wcove_bus_lock,
321 	.irq_bus_sync_unlock	= wcove_bus_sync_unlock,
322 };
323 
324 static irqreturn_t wcove_gpio_irq_handler(int irq, void *data)
325 {
326 	struct wcove_gpio *wg = (struct wcove_gpio *)data;
327 	unsigned int pending, virq, gpio, mask, offset;
328 	u8 p[2];
329 
330 	if (regmap_bulk_read(wg->regmap, IRQ_STATUS_BASE, p, 2)) {
331 		dev_err(wg->dev, "Failed to read irq status register\n");
332 		return IRQ_NONE;
333 	}
334 
335 	pending = (p[0] & GPIO_IRQ0_MASK) | ((p[1] & GPIO_IRQ1_MASK) << 7);
336 	if (!pending)
337 		return IRQ_NONE;
338 
339 	/* Iterate until no interrupt is pending */
340 	while (pending) {
341 		/* One iteration is for all pending bits */
342 		for_each_set_bit(gpio, (const unsigned long *)&pending,
343 						 WCOVE_GPIO_NUM) {
344 			offset = (gpio > GROUP0_NR_IRQS) ? 1 : 0;
345 			mask = (offset == 1) ? BIT(gpio - GROUP0_NR_IRQS) :
346 								BIT(gpio);
347 			virq = irq_find_mapping(wg->chip.irq.domain, gpio);
348 			handle_nested_irq(virq);
349 			regmap_update_bits(wg->regmap, IRQ_STATUS_BASE + offset,
350 								mask, mask);
351 		}
352 
353 		/* Next iteration */
354 		if (regmap_bulk_read(wg->regmap, IRQ_STATUS_BASE, p, 2)) {
355 			dev_err(wg->dev, "Failed to read irq status\n");
356 			break;
357 		}
358 
359 		pending = (p[0] & GPIO_IRQ0_MASK) | ((p[1] & GPIO_IRQ1_MASK) << 7);
360 	}
361 
362 	return IRQ_HANDLED;
363 }
364 
365 static void wcove_gpio_dbg_show(struct seq_file *s,
366 				      struct gpio_chip *chip)
367 {
368 	unsigned int ctlo, ctli, irq_mask, irq_status;
369 	struct wcove_gpio *wg = gpiochip_get_data(chip);
370 	int gpio, offset, group, ret = 0;
371 
372 	for (gpio = 0; gpio < WCOVE_GPIO_NUM; gpio++) {
373 		group = gpio < GROUP0_NR_IRQS ? 0 : 1;
374 		ret += regmap_read(wg->regmap, to_reg(gpio, CTRL_OUT), &ctlo);
375 		ret += regmap_read(wg->regmap, to_reg(gpio, CTRL_IN), &ctli);
376 		ret += regmap_read(wg->regmap, IRQ_MASK_BASE + group,
377 							&irq_mask);
378 		ret += regmap_read(wg->regmap, IRQ_STATUS_BASE + group,
379 							&irq_status);
380 		if (ret) {
381 			pr_err("Failed to read registers: ctrl out/in or irq status/mask\n");
382 			break;
383 		}
384 
385 		offset = gpio % 8;
386 		seq_printf(s, " gpio-%-2d %s %s %s %s ctlo=%2x,%s %s\n",
387 			   gpio, ctlo & CTLO_DIR_OUT ? "out" : "in ",
388 			   ctli & 0x1 ? "hi" : "lo",
389 			   ctli & CTLI_INTCNT_NE ? "fall" : "    ",
390 			   ctli & CTLI_INTCNT_PE ? "rise" : "    ",
391 			   ctlo,
392 			   irq_mask & BIT(offset) ? "mask  " : "unmask",
393 			   irq_status & BIT(offset) ? "pending" : "       ");
394 	}
395 }
396 
397 static int wcove_gpio_probe(struct platform_device *pdev)
398 {
399 	struct intel_soc_pmic *pmic;
400 	struct wcove_gpio *wg;
401 	int virq, ret, irq;
402 	struct device *dev;
403 
404 	/*
405 	 * This gpio platform device is created by a mfd device (see
406 	 * drivers/mfd/intel_soc_pmic_bxtwc.c for details). Information
407 	 * shared by all sub-devices created by the mfd device, the regmap
408 	 * pointer for instance, is stored as driver data of the mfd device
409 	 * driver.
410 	 */
411 	pmic = dev_get_drvdata(pdev->dev.parent);
412 	if (!pmic)
413 		return -ENODEV;
414 
415 	irq = platform_get_irq(pdev, 0);
416 	if (irq < 0)
417 		return irq;
418 
419 	dev = &pdev->dev;
420 
421 	wg = devm_kzalloc(dev, sizeof(*wg), GFP_KERNEL);
422 	if (!wg)
423 		return -ENOMEM;
424 
425 	wg->regmap_irq_chip = pmic->irq_chip_data;
426 
427 	platform_set_drvdata(pdev, wg);
428 
429 	mutex_init(&wg->buslock);
430 	wg->chip.label = KBUILD_MODNAME;
431 	wg->chip.direction_input = wcove_gpio_dir_in;
432 	wg->chip.direction_output = wcove_gpio_dir_out;
433 	wg->chip.get_direction = wcove_gpio_get_direction;
434 	wg->chip.get = wcove_gpio_get;
435 	wg->chip.set = wcove_gpio_set;
436 	wg->chip.set_config = wcove_gpio_set_config,
437 	wg->chip.base = -1;
438 	wg->chip.ngpio = WCOVE_VGPIO_NUM;
439 	wg->chip.can_sleep = true;
440 	wg->chip.parent = pdev->dev.parent;
441 	wg->chip.dbg_show = wcove_gpio_dbg_show;
442 	wg->dev = dev;
443 	wg->regmap = pmic->regmap;
444 
445 	ret = devm_gpiochip_add_data(dev, &wg->chip, wg);
446 	if (ret) {
447 		dev_err(dev, "Failed to add gpiochip: %d\n", ret);
448 		return ret;
449 	}
450 
451 	ret = gpiochip_irqchip_add_nested(&wg->chip, &wcove_irqchip, 0,
452 					  handle_simple_irq, IRQ_TYPE_NONE);
453 	if (ret) {
454 		dev_err(dev, "Failed to add irqchip: %d\n", ret);
455 		return ret;
456 	}
457 
458 	virq = regmap_irq_get_virq(wg->regmap_irq_chip, irq);
459 	if (virq < 0) {
460 		dev_err(dev, "Failed to get virq by irq %d\n", irq);
461 		return virq;
462 	}
463 
464 	ret = devm_request_threaded_irq(dev, virq, NULL,
465 		wcove_gpio_irq_handler, IRQF_ONESHOT, pdev->name, wg);
466 	if (ret) {
467 		dev_err(dev, "Failed to request irq %d\n", virq);
468 		return ret;
469 	}
470 
471 	gpiochip_set_nested_irqchip(&wg->chip, &wcove_irqchip, virq);
472 
473 	/* Enable GPIO0 interrupts */
474 	ret = regmap_update_bits(wg->regmap, IRQ_MASK_BASE, GPIO_IRQ0_MASK,
475 				 0x00);
476 	if (ret)
477 		return ret;
478 
479 	/* Enable GPIO1 interrupts */
480 	ret = regmap_update_bits(wg->regmap, IRQ_MASK_BASE + 1, GPIO_IRQ1_MASK,
481 				 0x00);
482 	if (ret)
483 		return ret;
484 
485 	return 0;
486 }
487 
488 /*
489  * Whiskey Cove PMIC itself is a analog device(but with digital control
490  * interface) providing power management support for other devices in
491  * the accompanied SoC, so we have no .pm for Whiskey Cove GPIO driver.
492  */
493 static struct platform_driver wcove_gpio_driver = {
494 	.driver = {
495 		.name = "bxt_wcove_gpio",
496 	},
497 	.probe = wcove_gpio_probe,
498 };
499 
500 module_platform_driver(wcove_gpio_driver);
501 
502 MODULE_AUTHOR("Ajay Thomas <ajay.thomas.david.rajamanickam@intel.com>");
503 MODULE_AUTHOR("Bin Gao <bin.gao@intel.com>");
504 MODULE_DESCRIPTION("Intel Whiskey Cove GPIO Driver");
505 MODULE_LICENSE("GPL v2");
506 MODULE_ALIAS("platform:bxt_wcove_gpio");
507