xref: /linux/drivers/gpio/gpio-wcove.c (revision c316cf670491def52a396d3bdc5a63ad01f7fefa)
1 /*
2  * Intel Whiskey Cove PMIC GPIO Driver
3  *
4  * This driver is written based on gpio-crystalcove.c
5  *
6  * Copyright (C) 2016 Intel Corporation. All rights reserved.
7  *
8  * This program is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU General Public License version
10  * 2 as published by the Free Software Foundation.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  */
17 
18 #include <linux/bitops.h>
19 #include <linux/module.h>
20 #include <linux/interrupt.h>
21 #include <linux/gpio/driver.h>
22 #include <linux/mfd/intel_soc_pmic.h>
23 #include <linux/platform_device.h>
24 #include <linux/regmap.h>
25 #include <linux/seq_file.h>
26 
27 /*
28  * Whiskey Cove PMIC has 13 physical GPIO pins divided into 3 banks:
29  * Bank 0: Pin 0 - 6
30  * Bank 1: Pin 7 - 10
31  * Bank 2: Pin 11 -12
32  * Each pin has one output control register and one input control register.
33  */
34 #define BANK0_NR_PINS		7
35 #define BANK1_NR_PINS		4
36 #define BANK2_NR_PINS		2
37 #define WCOVE_GPIO_NUM		(BANK0_NR_PINS + BANK1_NR_PINS + BANK2_NR_PINS)
38 #define WCOVE_VGPIO_NUM		94
39 /* GPIO output control registers (one per pin): 0x4e44 - 0x4e50 */
40 #define GPIO_OUT_CTRL_BASE	0x4e44
41 /* GPIO input control registers (one per pin): 0x4e51 - 0x4e5d */
42 #define GPIO_IN_CTRL_BASE	0x4e51
43 
44 /*
45  * GPIO interrupts are organized in two groups:
46  * Group 0: Bank 0 pins (Pin 0 - 6)
47  * Group 1: Bank 1 and Bank 2 pins (Pin 7 - 12)
48  * Each group has two registers (one bit per pin): status and mask.
49  */
50 #define GROUP0_NR_IRQS		7
51 #define GROUP1_NR_IRQS		6
52 #define IRQ_MASK_BASE		0x4e19
53 #define IRQ_STATUS_BASE		0x4e0b
54 #define GPIO_IRQ0_MASK		GENMASK(6, 0)
55 #define GPIO_IRQ1_MASK		GENMASK(5, 0)
56 #define UPDATE_IRQ_TYPE		BIT(0)
57 #define UPDATE_IRQ_MASK		BIT(1)
58 
59 #define CTLI_INTCNT_DIS		(0 << 1)
60 #define CTLI_INTCNT_NE		(1 << 1)
61 #define CTLI_INTCNT_PE		(2 << 1)
62 #define CTLI_INTCNT_BE		(3 << 1)
63 
64 #define CTLO_DIR_IN		(0 << 5)
65 #define CTLO_DIR_OUT		(1 << 5)
66 
67 #define CTLO_DRV_MASK		(1 << 4)
68 #define CTLO_DRV_OD		(0 << 4)
69 #define CTLO_DRV_CMOS		(1 << 4)
70 
71 #define CTLO_DRV_REN		(1 << 3)
72 
73 #define CTLO_RVAL_2KDOWN	(0 << 1)
74 #define CTLO_RVAL_2KUP		(1 << 1)
75 #define CTLO_RVAL_50KDOWN	(2 << 1)
76 #define CTLO_RVAL_50KUP		(3 << 1)
77 
78 #define CTLO_INPUT_SET	(CTLO_DRV_CMOS | CTLO_DRV_REN | CTLO_RVAL_2KUP)
79 #define CTLO_OUTPUT_SET	(CTLO_DIR_OUT | CTLO_INPUT_SET)
80 
81 enum ctrl_register {
82 	CTRL_IN,
83 	CTRL_OUT,
84 };
85 
86 /*
87  * struct wcove_gpio - Whiskey Cove GPIO controller
88  * @buslock: for bus lock/sync and unlock.
89  * @chip: the abstract gpio_chip structure.
90  * @dev: the gpio device
91  * @regmap: the regmap from the parent device.
92  * @regmap_irq_chip: the regmap of the gpio irq chip.
93  * @update: pending IRQ setting update, to be written to the chip upon unlock.
94  * @intcnt: the Interrupt Detect value to be written.
95  * @set_irq_mask: true if the IRQ mask needs to be set, false to clear.
96  */
97 struct wcove_gpio {
98 	struct mutex buslock;
99 	struct gpio_chip chip;
100 	struct device *dev;
101 	struct regmap *regmap;
102 	struct regmap_irq_chip_data *regmap_irq_chip;
103 	int update;
104 	int intcnt;
105 	bool set_irq_mask;
106 };
107 
108 static inline unsigned int to_reg(int gpio, enum ctrl_register reg_type)
109 {
110 	unsigned int reg;
111 	int bank;
112 
113 	if (gpio < BANK0_NR_PINS)
114 		bank = 0;
115 	else if (gpio < BANK0_NR_PINS + BANK1_NR_PINS)
116 		bank = 1;
117 	else
118 		bank = 2;
119 
120 	if (reg_type == CTRL_IN)
121 		reg = GPIO_IN_CTRL_BASE + bank;
122 	else
123 		reg = GPIO_OUT_CTRL_BASE + bank;
124 
125 	return reg;
126 }
127 
128 static void wcove_update_irq_mask(struct wcove_gpio *wg, int gpio)
129 {
130 	unsigned int reg, mask;
131 
132 	if (gpio < GROUP0_NR_IRQS) {
133 		reg = IRQ_MASK_BASE;
134 		mask = BIT(gpio % GROUP0_NR_IRQS);
135 	} else {
136 		reg = IRQ_MASK_BASE + 1;
137 		mask = BIT((gpio - GROUP0_NR_IRQS) % GROUP1_NR_IRQS);
138 	}
139 
140 	if (wg->set_irq_mask)
141 		regmap_update_bits(wg->regmap, reg, mask, mask);
142 	else
143 		regmap_update_bits(wg->regmap, reg, mask, 0);
144 }
145 
146 static void wcove_update_irq_ctrl(struct wcove_gpio *wg, int gpio)
147 {
148 	unsigned int reg = to_reg(gpio, CTRL_IN);
149 
150 	regmap_update_bits(wg->regmap, reg, CTLI_INTCNT_BE, wg->intcnt);
151 }
152 
153 static int wcove_gpio_dir_in(struct gpio_chip *chip, unsigned int gpio)
154 {
155 	struct wcove_gpio *wg = gpiochip_get_data(chip);
156 
157 	return regmap_write(wg->regmap, to_reg(gpio, CTRL_OUT),
158 			    CTLO_INPUT_SET);
159 }
160 
161 static int wcove_gpio_dir_out(struct gpio_chip *chip, unsigned int gpio,
162 				    int value)
163 {
164 	struct wcove_gpio *wg = gpiochip_get_data(chip);
165 
166 	return regmap_write(wg->regmap, to_reg(gpio, CTRL_OUT),
167 			    CTLO_OUTPUT_SET | value);
168 }
169 
170 static int wcove_gpio_get_direction(struct gpio_chip *chip, unsigned int gpio)
171 {
172 	struct wcove_gpio *wg = gpiochip_get_data(chip);
173 	unsigned int val;
174 	int ret;
175 
176 	ret = regmap_read(wg->regmap, to_reg(gpio, CTRL_OUT), &val);
177 	if (ret)
178 		return ret;
179 
180 	return !(val & CTLO_DIR_OUT);
181 }
182 
183 static int wcove_gpio_get(struct gpio_chip *chip, unsigned int gpio)
184 {
185 	struct wcove_gpio *wg = gpiochip_get_data(chip);
186 	unsigned int val;
187 	int ret;
188 
189 	ret = regmap_read(wg->regmap, to_reg(gpio, CTRL_IN), &val);
190 	if (ret)
191 		return ret;
192 
193 	return val & 0x1;
194 }
195 
196 static void wcove_gpio_set(struct gpio_chip *chip,
197 				 unsigned int gpio, int value)
198 {
199 	struct wcove_gpio *wg = gpiochip_get_data(chip);
200 
201 	if (value)
202 		regmap_update_bits(wg->regmap, to_reg(gpio, CTRL_OUT), 1, 1);
203 	else
204 		regmap_update_bits(wg->regmap, to_reg(gpio, CTRL_OUT), 1, 0);
205 }
206 
207 static int wcove_gpio_set_config(struct gpio_chip *chip, unsigned int gpio,
208 				 unsigned long config)
209 {
210 	struct wcove_gpio *wg = gpiochip_get_data(chip);
211 
212 	switch (pinconf_to_config_param(config)) {
213 	case PIN_CONFIG_DRIVE_OPEN_DRAIN:
214 		return regmap_update_bits(wg->regmap, to_reg(gpio, CTRL_OUT),
215 						CTLO_DRV_MASK, CTLO_DRV_OD);
216 	case PIN_CONFIG_DRIVE_PUSH_PULL:
217 		return regmap_update_bits(wg->regmap, to_reg(gpio, CTRL_OUT),
218 						CTLO_DRV_MASK, CTLO_DRV_CMOS);
219 	default:
220 		break;
221 	}
222 
223 	return -ENOTSUPP;
224 }
225 
226 static int wcove_irq_type(struct irq_data *data, unsigned int type)
227 {
228 	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
229 	struct wcove_gpio *wg = gpiochip_get_data(chip);
230 
231 	switch (type) {
232 	case IRQ_TYPE_NONE:
233 		wg->intcnt = CTLI_INTCNT_DIS;
234 		break;
235 	case IRQ_TYPE_EDGE_BOTH:
236 		wg->intcnt = CTLI_INTCNT_BE;
237 		break;
238 	case IRQ_TYPE_EDGE_RISING:
239 		wg->intcnt = CTLI_INTCNT_PE;
240 		break;
241 	case IRQ_TYPE_EDGE_FALLING:
242 		wg->intcnt = CTLI_INTCNT_NE;
243 		break;
244 	default:
245 		return -EINVAL;
246 	}
247 
248 	wg->update |= UPDATE_IRQ_TYPE;
249 
250 	return 0;
251 }
252 
253 static void wcove_bus_lock(struct irq_data *data)
254 {
255 	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
256 	struct wcove_gpio *wg = gpiochip_get_data(chip);
257 
258 	mutex_lock(&wg->buslock);
259 }
260 
261 static void wcove_bus_sync_unlock(struct irq_data *data)
262 {
263 	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
264 	struct wcove_gpio *wg = gpiochip_get_data(chip);
265 	int gpio = data->hwirq;
266 
267 	if (wg->update & UPDATE_IRQ_TYPE)
268 		wcove_update_irq_ctrl(wg, gpio);
269 	if (wg->update & UPDATE_IRQ_MASK)
270 		wcove_update_irq_mask(wg, gpio);
271 	wg->update = 0;
272 
273 	mutex_unlock(&wg->buslock);
274 }
275 
276 static void wcove_irq_unmask(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 
281 	wg->set_irq_mask = false;
282 	wg->update |= UPDATE_IRQ_MASK;
283 }
284 
285 static void wcove_irq_mask(struct irq_data *data)
286 {
287 	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
288 	struct wcove_gpio *wg = gpiochip_get_data(chip);
289 
290 	wg->set_irq_mask = true;
291 	wg->update |= UPDATE_IRQ_MASK;
292 }
293 
294 static struct irq_chip wcove_irqchip = {
295 	.name			= "Whiskey Cove",
296 	.irq_mask		= wcove_irq_mask,
297 	.irq_unmask		= wcove_irq_unmask,
298 	.irq_set_type		= wcove_irq_type,
299 	.irq_bus_lock		= wcove_bus_lock,
300 	.irq_bus_sync_unlock	= wcove_bus_sync_unlock,
301 };
302 
303 static irqreturn_t wcove_gpio_irq_handler(int irq, void *data)
304 {
305 	struct wcove_gpio *wg = (struct wcove_gpio *)data;
306 	unsigned int pending, virq, gpio, mask, offset;
307 	u8 p[2];
308 
309 	if (regmap_bulk_read(wg->regmap, IRQ_STATUS_BASE, p, 2)) {
310 		dev_err(wg->dev, "Failed to read irq status register\n");
311 		return IRQ_NONE;
312 	}
313 
314 	pending = (p[0] & GPIO_IRQ0_MASK) | ((p[1] & GPIO_IRQ1_MASK) << 7);
315 	if (!pending)
316 		return IRQ_NONE;
317 
318 	/* Iterate until no interrupt is pending */
319 	while (pending) {
320 		/* One iteration is for all pending bits */
321 		for_each_set_bit(gpio, (const unsigned long *)&pending,
322 						 WCOVE_GPIO_NUM) {
323 			offset = (gpio > GROUP0_NR_IRQS) ? 1 : 0;
324 			mask = (offset == 1) ? BIT(gpio - GROUP0_NR_IRQS) :
325 								BIT(gpio);
326 			virq = irq_find_mapping(wg->chip.irqdomain, gpio);
327 			handle_nested_irq(virq);
328 			regmap_update_bits(wg->regmap, IRQ_STATUS_BASE + offset,
329 								mask, mask);
330 		}
331 
332 		/* Next iteration */
333 		if (regmap_bulk_read(wg->regmap, IRQ_STATUS_BASE, p, 2)) {
334 			dev_err(wg->dev, "Failed to read irq status\n");
335 			break;
336 		}
337 
338 		pending = (p[0] & GPIO_IRQ0_MASK) | ((p[1] & GPIO_IRQ1_MASK) << 7);
339 	}
340 
341 	return IRQ_HANDLED;
342 }
343 
344 static void wcove_gpio_dbg_show(struct seq_file *s,
345 				      struct gpio_chip *chip)
346 {
347 	unsigned int ctlo, ctli, irq_mask, irq_status;
348 	struct wcove_gpio *wg = gpiochip_get_data(chip);
349 	int gpio, offset, group, ret = 0;
350 
351 	for (gpio = 0; gpio < WCOVE_GPIO_NUM; gpio++) {
352 		group = gpio < GROUP0_NR_IRQS ? 0 : 1;
353 		ret += regmap_read(wg->regmap, to_reg(gpio, CTRL_OUT), &ctlo);
354 		ret += regmap_read(wg->regmap, to_reg(gpio, CTRL_IN), &ctli);
355 		ret += regmap_read(wg->regmap, IRQ_MASK_BASE + group,
356 							&irq_mask);
357 		ret += regmap_read(wg->regmap, IRQ_STATUS_BASE + group,
358 							&irq_status);
359 		if (ret) {
360 			pr_err("Failed to read registers: ctrl out/in or irq status/mask\n");
361 			break;
362 		}
363 
364 		offset = gpio % 8;
365 		seq_printf(s, " gpio-%-2d %s %s %s %s ctlo=%2x,%s %s\n",
366 			   gpio, ctlo & CTLO_DIR_OUT ? "out" : "in ",
367 			   ctli & 0x1 ? "hi" : "lo",
368 			   ctli & CTLI_INTCNT_NE ? "fall" : "    ",
369 			   ctli & CTLI_INTCNT_PE ? "rise" : "    ",
370 			   ctlo,
371 			   irq_mask & BIT(offset) ? "mask  " : "unmask",
372 			   irq_status & BIT(offset) ? "pending" : "       ");
373 	}
374 }
375 
376 static int wcove_gpio_probe(struct platform_device *pdev)
377 {
378 	struct intel_soc_pmic *pmic;
379 	struct wcove_gpio *wg;
380 	int virq, ret, irq;
381 	struct device *dev;
382 
383 	/*
384 	 * This gpio platform device is created by a mfd device (see
385 	 * drivers/mfd/intel_soc_pmic_bxtwc.c for details). Information
386 	 * shared by all sub-devices created by the mfd device, the regmap
387 	 * pointer for instance, is stored as driver data of the mfd device
388 	 * driver.
389 	 */
390 	pmic = dev_get_drvdata(pdev->dev.parent);
391 	if (!pmic)
392 		return -ENODEV;
393 
394 	irq = platform_get_irq(pdev, 0);
395 	if (irq < 0)
396 		return irq;
397 
398 	dev = &pdev->dev;
399 
400 	wg = devm_kzalloc(dev, sizeof(*wg), GFP_KERNEL);
401 	if (!wg)
402 		return -ENOMEM;
403 
404 	wg->regmap_irq_chip = pmic->irq_chip_data_level2;
405 
406 	platform_set_drvdata(pdev, wg);
407 
408 	mutex_init(&wg->buslock);
409 	wg->chip.label = KBUILD_MODNAME;
410 	wg->chip.direction_input = wcove_gpio_dir_in;
411 	wg->chip.direction_output = wcove_gpio_dir_out;
412 	wg->chip.get_direction = wcove_gpio_get_direction;
413 	wg->chip.get = wcove_gpio_get;
414 	wg->chip.set = wcove_gpio_set;
415 	wg->chip.set_config = wcove_gpio_set_config,
416 	wg->chip.base = -1;
417 	wg->chip.ngpio = WCOVE_VGPIO_NUM;
418 	wg->chip.can_sleep = true;
419 	wg->chip.parent = pdev->dev.parent;
420 	wg->chip.dbg_show = wcove_gpio_dbg_show;
421 	wg->dev = dev;
422 	wg->regmap = pmic->regmap;
423 
424 	ret = devm_gpiochip_add_data(dev, &wg->chip, wg);
425 	if (ret) {
426 		dev_err(dev, "Failed to add gpiochip: %d\n", ret);
427 		return ret;
428 	}
429 
430 	ret = gpiochip_irqchip_add_nested(&wg->chip, &wcove_irqchip, 0,
431 					  handle_simple_irq, IRQ_TYPE_NONE);
432 	if (ret) {
433 		dev_err(dev, "Failed to add irqchip: %d\n", ret);
434 		return ret;
435 	}
436 
437 	virq = regmap_irq_get_virq(wg->regmap_irq_chip, irq);
438 	if (virq < 0) {
439 		dev_err(dev, "Failed to get virq by irq %d\n", irq);
440 		return virq;
441 	}
442 
443 	ret = devm_request_threaded_irq(dev, virq, NULL,
444 		wcove_gpio_irq_handler, IRQF_ONESHOT, pdev->name, wg);
445 	if (ret) {
446 		dev_err(dev, "Failed to request irq %d\n", virq);
447 		return ret;
448 	}
449 
450 	gpiochip_set_nested_irqchip(&wg->chip, &wcove_irqchip, virq);
451 
452 	return 0;
453 }
454 
455 /*
456  * Whiskey Cove PMIC itself is a analog device(but with digital control
457  * interface) providing power management support for other devices in
458  * the accompanied SoC, so we have no .pm for Whiskey Cove GPIO driver.
459  */
460 static struct platform_driver wcove_gpio_driver = {
461 	.driver = {
462 		.name = "bxt_wcove_gpio",
463 	},
464 	.probe = wcove_gpio_probe,
465 };
466 
467 module_platform_driver(wcove_gpio_driver);
468 
469 MODULE_AUTHOR("Ajay Thomas <ajay.thomas.david.rajamanickam@intel.com>");
470 MODULE_AUTHOR("Bin Gao <bin.gao@intel.com>");
471 MODULE_DESCRIPTION("Intel Whiskey Cove GPIO Driver");
472 MODULE_LICENSE("GPL v2");
473 MODULE_ALIAS("platform:bxt_wcove_gpio");
474