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 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
182static 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
198static 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
212static 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
235static 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
265static 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
273static 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
288static 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
300static 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
312static 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
321static 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
362static 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
394static 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 */
490static struct platform_driver wcove_gpio_driver = {
491 .driver = {
492 .name = "bxt_wcove_gpio",
493 },
494 .probe = wcove_gpio_probe,
495};
496
497module_platform_driver(wcove_gpio_driver);
498
499MODULE_AUTHOR("Ajay Thomas <ajay.thomas.david.rajamanickam@intel.com>");
500MODULE_AUTHOR("Bin Gao <bin.gao@intel.com>");
501MODULE_DESCRIPTION("Intel Whiskey Cove GPIO Driver");
502MODULE_LICENSE("GPL v2");
503MODULE_ALIAS("platform:bxt_wcove_gpio");
504