xref: /openbmc/linux/drivers/gpio/gpio-wcove.c (revision 2645d8d0)
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 0;
174 
175 	ret = regmap_read(wg->regmap, reg, &val);
176 	if (ret)
177 		return ret;
178 
179 	return !(val & CTLO_DIR_OUT);
180 }
181 
182 static int wcove_gpio_get(struct gpio_chip *chip, unsigned int gpio)
183 {
184 	struct wcove_gpio *wg = gpiochip_get_data(chip);
185 	unsigned int val;
186 	int ret, reg = to_reg(gpio, CTRL_IN);
187 
188 	if (reg < 0)
189 		return 0;
190 
191 	ret = regmap_read(wg->regmap, reg, &val);
192 	if (ret)
193 		return ret;
194 
195 	return val & 0x1;
196 }
197 
198 static void wcove_gpio_set(struct gpio_chip *chip, unsigned int gpio, int value)
199 {
200 	struct wcove_gpio *wg = gpiochip_get_data(chip);
201 	int reg = to_reg(gpio, CTRL_OUT);
202 
203 	if (reg < 0)
204 		return;
205 
206 	if (value)
207 		regmap_update_bits(wg->regmap, reg, 1, 1);
208 	else
209 		regmap_update_bits(wg->regmap, reg, 1, 0);
210 }
211 
212 static int wcove_gpio_set_config(struct gpio_chip *chip, unsigned int gpio,
213 				 unsigned long config)
214 {
215 	struct wcove_gpio *wg = gpiochip_get_data(chip);
216 	int reg = to_reg(gpio, CTRL_OUT);
217 
218 	if (reg < 0)
219 		return 0;
220 
221 	switch (pinconf_to_config_param(config)) {
222 	case PIN_CONFIG_DRIVE_OPEN_DRAIN:
223 		return regmap_update_bits(wg->regmap, reg, CTLO_DRV_MASK,
224 					  CTLO_DRV_OD);
225 	case PIN_CONFIG_DRIVE_PUSH_PULL:
226 		return regmap_update_bits(wg->regmap, reg, CTLO_DRV_MASK,
227 					  CTLO_DRV_CMOS);
228 	default:
229 		break;
230 	}
231 
232 	return -ENOTSUPP;
233 }
234 
235 static int wcove_irq_type(struct irq_data *data, unsigned int type)
236 {
237 	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
238 	struct wcove_gpio *wg = gpiochip_get_data(chip);
239 
240 	if (data->hwirq >= WCOVE_GPIO_NUM)
241 		return 0;
242 
243 	switch (type) {
244 	case IRQ_TYPE_NONE:
245 		wg->intcnt = CTLI_INTCNT_DIS;
246 		break;
247 	case IRQ_TYPE_EDGE_BOTH:
248 		wg->intcnt = CTLI_INTCNT_BE;
249 		break;
250 	case IRQ_TYPE_EDGE_RISING:
251 		wg->intcnt = CTLI_INTCNT_PE;
252 		break;
253 	case IRQ_TYPE_EDGE_FALLING:
254 		wg->intcnt = CTLI_INTCNT_NE;
255 		break;
256 	default:
257 		return -EINVAL;
258 	}
259 
260 	wg->update |= UPDATE_IRQ_TYPE;
261 
262 	return 0;
263 }
264 
265 static void wcove_bus_lock(struct irq_data *data)
266 {
267 	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
268 	struct wcove_gpio *wg = gpiochip_get_data(chip);
269 
270 	mutex_lock(&wg->buslock);
271 }
272 
273 static void wcove_bus_sync_unlock(struct irq_data *data)
274 {
275 	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
276 	struct wcove_gpio *wg = gpiochip_get_data(chip);
277 	int gpio = data->hwirq;
278 
279 	if (wg->update & UPDATE_IRQ_TYPE)
280 		wcove_update_irq_ctrl(wg, gpio);
281 	if (wg->update & UPDATE_IRQ_MASK)
282 		wcove_update_irq_mask(wg, gpio);
283 	wg->update = 0;
284 
285 	mutex_unlock(&wg->buslock);
286 }
287 
288 static void wcove_irq_unmask(struct irq_data *data)
289 {
290 	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
291 	struct wcove_gpio *wg = gpiochip_get_data(chip);
292 
293 	if (data->hwirq >= WCOVE_GPIO_NUM)
294 		return;
295 
296 	wg->set_irq_mask = false;
297 	wg->update |= UPDATE_IRQ_MASK;
298 }
299 
300 static void wcove_irq_mask(struct irq_data *data)
301 {
302 	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
303 	struct wcove_gpio *wg = gpiochip_get_data(chip);
304 
305 	if (data->hwirq >= WCOVE_GPIO_NUM)
306 		return;
307 
308 	wg->set_irq_mask = true;
309 	wg->update |= UPDATE_IRQ_MASK;
310 }
311 
312 static struct irq_chip wcove_irqchip = {
313 	.name			= "Whiskey Cove",
314 	.irq_mask		= wcove_irq_mask,
315 	.irq_unmask		= wcove_irq_unmask,
316 	.irq_set_type		= wcove_irq_type,
317 	.irq_bus_lock		= wcove_bus_lock,
318 	.irq_bus_sync_unlock	= wcove_bus_sync_unlock,
319 };
320 
321 static irqreturn_t wcove_gpio_irq_handler(int irq, void *data)
322 {
323 	struct wcove_gpio *wg = (struct wcove_gpio *)data;
324 	unsigned int pending, virq, gpio, mask, offset;
325 	u8 p[2];
326 
327 	if (regmap_bulk_read(wg->regmap, IRQ_STATUS_BASE, p, 2)) {
328 		dev_err(wg->dev, "Failed to read irq status register\n");
329 		return IRQ_NONE;
330 	}
331 
332 	pending = (p[0] & GPIO_IRQ0_MASK) | ((p[1] & GPIO_IRQ1_MASK) << 7);
333 	if (!pending)
334 		return IRQ_NONE;
335 
336 	/* Iterate until no interrupt is pending */
337 	while (pending) {
338 		/* One iteration is for all pending bits */
339 		for_each_set_bit(gpio, (const unsigned long *)&pending,
340 						 WCOVE_GPIO_NUM) {
341 			offset = (gpio > GROUP0_NR_IRQS) ? 1 : 0;
342 			mask = (offset == 1) ? BIT(gpio - GROUP0_NR_IRQS) :
343 								BIT(gpio);
344 			virq = irq_find_mapping(wg->chip.irq.domain, gpio);
345 			handle_nested_irq(virq);
346 			regmap_update_bits(wg->regmap, IRQ_STATUS_BASE + offset,
347 								mask, mask);
348 		}
349 
350 		/* Next iteration */
351 		if (regmap_bulk_read(wg->regmap, IRQ_STATUS_BASE, p, 2)) {
352 			dev_err(wg->dev, "Failed to read irq status\n");
353 			break;
354 		}
355 
356 		pending = (p[0] & GPIO_IRQ0_MASK) | ((p[1] & GPIO_IRQ1_MASK) << 7);
357 	}
358 
359 	return IRQ_HANDLED;
360 }
361 
362 static void wcove_gpio_dbg_show(struct seq_file *s,
363 				      struct gpio_chip *chip)
364 {
365 	unsigned int ctlo, ctli, irq_mask, irq_status;
366 	struct wcove_gpio *wg = gpiochip_get_data(chip);
367 	int gpio, offset, group, ret = 0;
368 
369 	for (gpio = 0; gpio < WCOVE_GPIO_NUM; gpio++) {
370 		group = gpio < GROUP0_NR_IRQS ? 0 : 1;
371 		ret += regmap_read(wg->regmap, to_reg(gpio, CTRL_OUT), &ctlo);
372 		ret += regmap_read(wg->regmap, to_reg(gpio, CTRL_IN), &ctli);
373 		ret += regmap_read(wg->regmap, IRQ_MASK_BASE + group,
374 							&irq_mask);
375 		ret += regmap_read(wg->regmap, IRQ_STATUS_BASE + group,
376 							&irq_status);
377 		if (ret) {
378 			pr_err("Failed to read registers: ctrl out/in or irq status/mask\n");
379 			break;
380 		}
381 
382 		offset = gpio % 8;
383 		seq_printf(s, " gpio-%-2d %s %s %s %s ctlo=%2x,%s %s\n",
384 			   gpio, ctlo & CTLO_DIR_OUT ? "out" : "in ",
385 			   ctli & 0x1 ? "hi" : "lo",
386 			   ctli & CTLI_INTCNT_NE ? "fall" : "    ",
387 			   ctli & CTLI_INTCNT_PE ? "rise" : "    ",
388 			   ctlo,
389 			   irq_mask & BIT(offset) ? "mask  " : "unmask",
390 			   irq_status & BIT(offset) ? "pending" : "       ");
391 	}
392 }
393 
394 static int wcove_gpio_probe(struct platform_device *pdev)
395 {
396 	struct intel_soc_pmic *pmic;
397 	struct wcove_gpio *wg;
398 	int virq, ret, irq;
399 	struct device *dev;
400 
401 	/*
402 	 * This gpio platform device is created by a mfd device (see
403 	 * drivers/mfd/intel_soc_pmic_bxtwc.c for details). Information
404 	 * shared by all sub-devices created by the mfd device, the regmap
405 	 * pointer for instance, is stored as driver data of the mfd device
406 	 * driver.
407 	 */
408 	pmic = dev_get_drvdata(pdev->dev.parent);
409 	if (!pmic)
410 		return -ENODEV;
411 
412 	irq = platform_get_irq(pdev, 0);
413 	if (irq < 0)
414 		return irq;
415 
416 	dev = &pdev->dev;
417 
418 	wg = devm_kzalloc(dev, sizeof(*wg), GFP_KERNEL);
419 	if (!wg)
420 		return -ENOMEM;
421 
422 	wg->regmap_irq_chip = pmic->irq_chip_data;
423 
424 	platform_set_drvdata(pdev, wg);
425 
426 	mutex_init(&wg->buslock);
427 	wg->chip.label = KBUILD_MODNAME;
428 	wg->chip.direction_input = wcove_gpio_dir_in;
429 	wg->chip.direction_output = wcove_gpio_dir_out;
430 	wg->chip.get_direction = wcove_gpio_get_direction;
431 	wg->chip.get = wcove_gpio_get;
432 	wg->chip.set = wcove_gpio_set;
433 	wg->chip.set_config = wcove_gpio_set_config,
434 	wg->chip.base = -1;
435 	wg->chip.ngpio = WCOVE_VGPIO_NUM;
436 	wg->chip.can_sleep = true;
437 	wg->chip.parent = pdev->dev.parent;
438 	wg->chip.dbg_show = wcove_gpio_dbg_show;
439 	wg->dev = dev;
440 	wg->regmap = pmic->regmap;
441 
442 	ret = devm_gpiochip_add_data(dev, &wg->chip, wg);
443 	if (ret) {
444 		dev_err(dev, "Failed to add gpiochip: %d\n", ret);
445 		return ret;
446 	}
447 
448 	ret = gpiochip_irqchip_add_nested(&wg->chip, &wcove_irqchip, 0,
449 					  handle_simple_irq, IRQ_TYPE_NONE);
450 	if (ret) {
451 		dev_err(dev, "Failed to add irqchip: %d\n", ret);
452 		return ret;
453 	}
454 
455 	virq = regmap_irq_get_virq(wg->regmap_irq_chip, irq);
456 	if (virq < 0) {
457 		dev_err(dev, "Failed to get virq by irq %d\n", irq);
458 		return virq;
459 	}
460 
461 	ret = devm_request_threaded_irq(dev, virq, NULL,
462 		wcove_gpio_irq_handler, IRQF_ONESHOT, pdev->name, wg);
463 	if (ret) {
464 		dev_err(dev, "Failed to request irq %d\n", virq);
465 		return ret;
466 	}
467 
468 	gpiochip_set_nested_irqchip(&wg->chip, &wcove_irqchip, virq);
469 
470 	/* Enable GPIO0 interrupts */
471 	ret = regmap_update_bits(wg->regmap, IRQ_MASK_BASE, GPIO_IRQ0_MASK,
472 				 0x00);
473 	if (ret)
474 		return ret;
475 
476 	/* Enable GPIO1 interrupts */
477 	ret = regmap_update_bits(wg->regmap, IRQ_MASK_BASE + 1, GPIO_IRQ1_MASK,
478 				 0x00);
479 	if (ret)
480 		return ret;
481 
482 	return 0;
483 }
484 
485 /*
486  * Whiskey Cove PMIC itself is a analog device(but with digital control
487  * interface) providing power management support for other devices in
488  * the accompanied SoC, so we have no .pm for Whiskey Cove GPIO driver.
489  */
490 static struct platform_driver wcove_gpio_driver = {
491 	.driver = {
492 		.name = "bxt_wcove_gpio",
493 	},
494 	.probe = wcove_gpio_probe,
495 };
496 
497 module_platform_driver(wcove_gpio_driver);
498 
499 MODULE_AUTHOR("Ajay Thomas <ajay.thomas.david.rajamanickam@intel.com>");
500 MODULE_AUTHOR("Bin Gao <bin.gao@intel.com>");
501 MODULE_DESCRIPTION("Intel Whiskey Cove GPIO Driver");
502 MODULE_LICENSE("GPL v2");
503 MODULE_ALIAS("platform:bxt_wcove_gpio");
504