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  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
 73enum 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 */
 89struct 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
100static 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
115static 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
133static 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
143static 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
154static 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
166static 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
185static 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
201static 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
215static 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
238static 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
268static 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
276static 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
291static 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
303static 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
315static 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
324static 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
365static 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
397static 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	struct gpio_irq_chip *girq;
404
405	/*
406	 * This gpio platform device is created by a mfd device (see
407	 * drivers/mfd/intel_soc_pmic_bxtwc.c for details). Information
408	 * shared by all sub-devices created by the mfd device, the regmap
409	 * pointer for instance, is stored as driver data of the mfd device
410	 * driver.
411	 */
412	pmic = dev_get_drvdata(pdev->dev.parent);
413	if (!pmic)
414		return -ENODEV;
415
416	irq = platform_get_irq(pdev, 0);
417	if (irq < 0)
418		return irq;
419
420	dev = &pdev->dev;
421
422	wg = devm_kzalloc(dev, sizeof(*wg), GFP_KERNEL);
423	if (!wg)
424		return -ENOMEM;
425
426	wg->regmap_irq_chip = pmic->irq_chip_data;
427
428	platform_set_drvdata(pdev, wg);
429
430	mutex_init(&wg->buslock);
431	wg->chip.label = KBUILD_MODNAME;
432	wg->chip.direction_input = wcove_gpio_dir_in;
433	wg->chip.direction_output = wcove_gpio_dir_out;
434	wg->chip.get_direction = wcove_gpio_get_direction;
435	wg->chip.get = wcove_gpio_get;
436	wg->chip.set = wcove_gpio_set;
437	wg->chip.set_config = wcove_gpio_set_config,
438	wg->chip.base = -1;
439	wg->chip.ngpio = WCOVE_VGPIO_NUM;
440	wg->chip.can_sleep = true;
441	wg->chip.parent = pdev->dev.parent;
442	wg->chip.dbg_show = wcove_gpio_dbg_show;
443	wg->dev = dev;
444	wg->regmap = pmic->regmap;
445
446	virq = regmap_irq_get_virq(wg->regmap_irq_chip, irq);
447	if (virq < 0) {
448		dev_err(dev, "Failed to get virq by irq %d\n", irq);
449		return virq;
450	}
451
452	girq = &wg->chip.irq;
453	girq->chip = &wcove_irqchip;
454	/* This will let us handle the parent IRQ in the driver */
455	girq->parent_handler = NULL;
456	girq->num_parents = 0;
457	girq->parents = NULL;
458	girq->default_type = IRQ_TYPE_NONE;
459	girq->handler = handle_simple_irq;
460	girq->threaded = true;
461
462	ret = devm_request_threaded_irq(dev, virq, NULL, wcove_gpio_irq_handler,
463					IRQF_ONESHOT, pdev->name, wg);
464	if (ret) {
465		dev_err(dev, "Failed to request irq %d\n", virq);
466		return ret;
467	}
468
469	ret = devm_gpiochip_add_data(dev, &wg->chip, wg);
470	if (ret) {
471		dev_err(dev, "Failed to add gpiochip: %d\n", ret);
472		return ret;
473	}
474
475	/* Enable GPIO0 interrupts */
476	ret = regmap_update_bits(wg->regmap, IRQ_MASK_BASE, GPIO_IRQ0_MASK,
477				 0x00);
478	if (ret)
479		return ret;
480
481	/* Enable GPIO1 interrupts */
482	ret = regmap_update_bits(wg->regmap, IRQ_MASK_BASE + 1, GPIO_IRQ1_MASK,
483				 0x00);
484	if (ret)
485		return ret;
486
487	return 0;
488}
489
490/*
491 * Whiskey Cove PMIC itself is a analog device(but with digital control
492 * interface) providing power management support for other devices in
493 * the accompanied SoC, so we have no .pm for Whiskey Cove GPIO driver.
494 */
495static struct platform_driver wcove_gpio_driver = {
496	.driver = {
497		.name = "bxt_wcove_gpio",
498	},
499	.probe = wcove_gpio_probe,
500};
501
502module_platform_driver(wcove_gpio_driver);
503
504MODULE_AUTHOR("Ajay Thomas <ajay.thomas.david.rajamanickam@intel.com>");
505MODULE_AUTHOR("Bin Gao <bin.gao@intel.com>");
506MODULE_DESCRIPTION("Intel Whiskey Cove GPIO Driver");
507MODULE_LICENSE("GPL v2");
508MODULE_ALIAS("platform:bxt_wcove_gpio");