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
to_reg(int gpio,enum ctrl_register reg_type)108 static inline unsigned int to_reg(int gpio, enum ctrl_register reg_type)
109 {
110 unsigned int reg;
111
112 if (gpio >= WCOVE_GPIO_NUM)
113 return -EOPNOTSUPP;
114
115 if (reg_type == CTRL_IN)
116 reg = GPIO_IN_CTRL_BASE + gpio;
117 else
118 reg = GPIO_OUT_CTRL_BASE + gpio;
119
120 return reg;
121 }
122
wcove_update_irq_mask(struct wcove_gpio * wg,int gpio)123 static void wcove_update_irq_mask(struct wcove_gpio *wg, int gpio)
124 {
125 unsigned int reg, mask;
126
127 if (gpio < GROUP0_NR_IRQS) {
128 reg = IRQ_MASK_BASE;
129 mask = BIT(gpio % GROUP0_NR_IRQS);
130 } else {
131 reg = IRQ_MASK_BASE + 1;
132 mask = BIT((gpio - GROUP0_NR_IRQS) % GROUP1_NR_IRQS);
133 }
134
135 if (wg->set_irq_mask)
136 regmap_update_bits(wg->regmap, reg, mask, mask);
137 else
138 regmap_update_bits(wg->regmap, reg, mask, 0);
139 }
140
wcove_update_irq_ctrl(struct wcove_gpio * wg,int gpio)141 static void wcove_update_irq_ctrl(struct wcove_gpio *wg, int gpio)
142 {
143 int reg = to_reg(gpio, CTRL_IN);
144
145 if (reg < 0)
146 return;
147
148 regmap_update_bits(wg->regmap, reg, CTLI_INTCNT_BE, wg->intcnt);
149 }
150
wcove_gpio_dir_in(struct gpio_chip * chip,unsigned int gpio)151 static int wcove_gpio_dir_in(struct gpio_chip *chip, unsigned int gpio)
152 {
153 struct wcove_gpio *wg = gpiochip_get_data(chip);
154 int reg = to_reg(gpio, CTRL_OUT);
155
156 if (reg < 0)
157 return 0;
158
159 return regmap_write(wg->regmap, reg, CTLO_INPUT_SET);
160 }
161
wcove_gpio_dir_out(struct gpio_chip * chip,unsigned int gpio,int value)162 static int wcove_gpio_dir_out(struct gpio_chip *chip, unsigned int gpio,
163 int value)
164 {
165 struct wcove_gpio *wg = gpiochip_get_data(chip);
166 int reg = to_reg(gpio, CTRL_OUT);
167
168 if (reg < 0)
169 return 0;
170
171 return regmap_write(wg->regmap, reg, CTLO_OUTPUT_SET | value);
172 }
173
wcove_gpio_get_direction(struct gpio_chip * chip,unsigned int gpio)174 static int wcove_gpio_get_direction(struct gpio_chip *chip, unsigned int gpio)
175 {
176 struct wcove_gpio *wg = gpiochip_get_data(chip);
177 unsigned int val;
178 int ret, reg = to_reg(gpio, CTRL_OUT);
179
180 if (reg < 0)
181 return 0;
182
183 ret = regmap_read(wg->regmap, reg, &val);
184 if (ret)
185 return ret;
186
187 return !(val & CTLO_DIR_OUT);
188 }
189
wcove_gpio_get(struct gpio_chip * chip,unsigned int gpio)190 static int wcove_gpio_get(struct gpio_chip *chip, unsigned int gpio)
191 {
192 struct wcove_gpio *wg = gpiochip_get_data(chip);
193 unsigned int val;
194 int ret, reg = to_reg(gpio, CTRL_IN);
195
196 if (reg < 0)
197 return 0;
198
199 ret = regmap_read(wg->regmap, reg, &val);
200 if (ret)
201 return ret;
202
203 return val & 0x1;
204 }
205
wcove_gpio_set(struct gpio_chip * chip,unsigned int gpio,int value)206 static void wcove_gpio_set(struct gpio_chip *chip,
207 unsigned int gpio, int value)
208 {
209 struct wcove_gpio *wg = gpiochip_get_data(chip);
210 int reg = to_reg(gpio, CTRL_OUT);
211
212 if (reg < 0)
213 return;
214
215 if (value)
216 regmap_update_bits(wg->regmap, reg, 1, 1);
217 else
218 regmap_update_bits(wg->regmap, reg, 1, 0);
219 }
220
wcove_gpio_set_config(struct gpio_chip * chip,unsigned int gpio,unsigned long config)221 static int wcove_gpio_set_config(struct gpio_chip *chip, unsigned int gpio,
222 unsigned long config)
223 {
224 struct wcove_gpio *wg = gpiochip_get_data(chip);
225 int reg = to_reg(gpio, CTRL_OUT);
226
227 if (reg < 0)
228 return 0;
229
230 switch (pinconf_to_config_param(config)) {
231 case PIN_CONFIG_DRIVE_OPEN_DRAIN:
232 return regmap_update_bits(wg->regmap, reg, CTLO_DRV_MASK,
233 CTLO_DRV_OD);
234 case PIN_CONFIG_DRIVE_PUSH_PULL:
235 return regmap_update_bits(wg->regmap, reg, CTLO_DRV_MASK,
236 CTLO_DRV_CMOS);
237 default:
238 break;
239 }
240
241 return -ENOTSUPP;
242 }
243
wcove_irq_type(struct irq_data * data,unsigned int type)244 static int wcove_irq_type(struct irq_data *data, unsigned int type)
245 {
246 struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
247 struct wcove_gpio *wg = gpiochip_get_data(chip);
248
249 if (data->hwirq >= WCOVE_GPIO_NUM)
250 return 0;
251
252 switch (type) {
253 case IRQ_TYPE_NONE:
254 wg->intcnt = CTLI_INTCNT_DIS;
255 break;
256 case IRQ_TYPE_EDGE_BOTH:
257 wg->intcnt = CTLI_INTCNT_BE;
258 break;
259 case IRQ_TYPE_EDGE_RISING:
260 wg->intcnt = CTLI_INTCNT_PE;
261 break;
262 case IRQ_TYPE_EDGE_FALLING:
263 wg->intcnt = CTLI_INTCNT_NE;
264 break;
265 default:
266 return -EINVAL;
267 }
268
269 wg->update |= UPDATE_IRQ_TYPE;
270
271 return 0;
272 }
273
wcove_bus_lock(struct irq_data * data)274 static void wcove_bus_lock(struct irq_data *data)
275 {
276 struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
277 struct wcove_gpio *wg = gpiochip_get_data(chip);
278
279 mutex_lock(&wg->buslock);
280 }
281
wcove_bus_sync_unlock(struct irq_data * data)282 static void wcove_bus_sync_unlock(struct irq_data *data)
283 {
284 struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
285 struct wcove_gpio *wg = gpiochip_get_data(chip);
286 int gpio = data->hwirq;
287
288 if (wg->update & UPDATE_IRQ_TYPE)
289 wcove_update_irq_ctrl(wg, gpio);
290 if (wg->update & UPDATE_IRQ_MASK)
291 wcove_update_irq_mask(wg, gpio);
292 wg->update = 0;
293
294 mutex_unlock(&wg->buslock);
295 }
296
wcove_irq_unmask(struct irq_data * data)297 static void wcove_irq_unmask(struct irq_data *data)
298 {
299 struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
300 struct wcove_gpio *wg = gpiochip_get_data(chip);
301
302 if (data->hwirq >= WCOVE_GPIO_NUM)
303 return;
304
305 wg->set_irq_mask = false;
306 wg->update |= UPDATE_IRQ_MASK;
307 }
308
wcove_irq_mask(struct irq_data * data)309 static void wcove_irq_mask(struct irq_data *data)
310 {
311 struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
312 struct wcove_gpio *wg = gpiochip_get_data(chip);
313
314 if (data->hwirq >= WCOVE_GPIO_NUM)
315 return;
316
317 wg->set_irq_mask = true;
318 wg->update |= UPDATE_IRQ_MASK;
319 }
320
321 static struct irq_chip wcove_irqchip = {
322 .name = "Whiskey Cove",
323 .irq_mask = wcove_irq_mask,
324 .irq_unmask = wcove_irq_unmask,
325 .irq_set_type = wcove_irq_type,
326 .irq_bus_lock = wcove_bus_lock,
327 .irq_bus_sync_unlock = wcove_bus_sync_unlock,
328 };
329
wcove_gpio_irq_handler(int irq,void * data)330 static irqreturn_t wcove_gpio_irq_handler(int irq, void *data)
331 {
332 struct wcove_gpio *wg = (struct wcove_gpio *)data;
333 unsigned int pending, virq, gpio, mask, offset;
334 u8 p[2];
335
336 if (regmap_bulk_read(wg->regmap, IRQ_STATUS_BASE, p, 2)) {
337 dev_err(wg->dev, "Failed to read irq status register\n");
338 return IRQ_NONE;
339 }
340
341 pending = (p[0] & GPIO_IRQ0_MASK) | ((p[1] & GPIO_IRQ1_MASK) << 7);
342 if (!pending)
343 return IRQ_NONE;
344
345 /* Iterate until no interrupt is pending */
346 while (pending) {
347 /* One iteration is for all pending bits */
348 for_each_set_bit(gpio, (const unsigned long *)&pending,
349 WCOVE_GPIO_NUM) {
350 offset = (gpio > GROUP0_NR_IRQS) ? 1 : 0;
351 mask = (offset == 1) ? BIT(gpio - GROUP0_NR_IRQS) :
352 BIT(gpio);
353 virq = irq_find_mapping(wg->chip.irq.domain, gpio);
354 handle_nested_irq(virq);
355 regmap_update_bits(wg->regmap, IRQ_STATUS_BASE + offset,
356 mask, mask);
357 }
358
359 /* Next iteration */
360 if (regmap_bulk_read(wg->regmap, IRQ_STATUS_BASE, p, 2)) {
361 dev_err(wg->dev, "Failed to read irq status\n");
362 break;
363 }
364
365 pending = (p[0] & GPIO_IRQ0_MASK) | ((p[1] & GPIO_IRQ1_MASK) << 7);
366 }
367
368 return IRQ_HANDLED;
369 }
370
wcove_gpio_dbg_show(struct seq_file * s,struct gpio_chip * chip)371 static void wcove_gpio_dbg_show(struct seq_file *s,
372 struct gpio_chip *chip)
373 {
374 unsigned int ctlo, ctli, irq_mask, irq_status;
375 struct wcove_gpio *wg = gpiochip_get_data(chip);
376 int gpio, offset, group, ret = 0;
377
378 for (gpio = 0; gpio < WCOVE_GPIO_NUM; gpio++) {
379 group = gpio < GROUP0_NR_IRQS ? 0 : 1;
380 ret += regmap_read(wg->regmap, to_reg(gpio, CTRL_OUT), &ctlo);
381 ret += regmap_read(wg->regmap, to_reg(gpio, CTRL_IN), &ctli);
382 ret += regmap_read(wg->regmap, IRQ_MASK_BASE + group,
383 &irq_mask);
384 ret += regmap_read(wg->regmap, IRQ_STATUS_BASE + group,
385 &irq_status);
386 if (ret) {
387 pr_err("Failed to read registers: ctrl out/in or irq status/mask\n");
388 break;
389 }
390
391 offset = gpio % 8;
392 seq_printf(s, " gpio-%-2d %s %s %s %s ctlo=%2x,%s %s\n",
393 gpio, ctlo & CTLO_DIR_OUT ? "out" : "in ",
394 ctli & 0x1 ? "hi" : "lo",
395 ctli & CTLI_INTCNT_NE ? "fall" : " ",
396 ctli & CTLI_INTCNT_PE ? "rise" : " ",
397 ctlo,
398 irq_mask & BIT(offset) ? "mask " : "unmask",
399 irq_status & BIT(offset) ? "pending" : " ");
400 }
401 }
402
wcove_gpio_probe(struct platform_device * pdev)403 static int wcove_gpio_probe(struct platform_device *pdev)
404 {
405 struct intel_soc_pmic *pmic;
406 struct wcove_gpio *wg;
407 int virq, ret, irq;
408 struct device *dev;
409
410 /*
411 * This gpio platform device is created by a mfd device (see
412 * drivers/mfd/intel_soc_pmic_bxtwc.c for details). Information
413 * shared by all sub-devices created by the mfd device, the regmap
414 * pointer for instance, is stored as driver data of the mfd device
415 * driver.
416 */
417 pmic = dev_get_drvdata(pdev->dev.parent);
418 if (!pmic)
419 return -ENODEV;
420
421 irq = platform_get_irq(pdev, 0);
422 if (irq < 0)
423 return irq;
424
425 dev = &pdev->dev;
426
427 wg = devm_kzalloc(dev, sizeof(*wg), GFP_KERNEL);
428 if (!wg)
429 return -ENOMEM;
430
431 wg->regmap_irq_chip = pmic->irq_chip_data;
432
433 platform_set_drvdata(pdev, wg);
434
435 mutex_init(&wg->buslock);
436 wg->chip.label = KBUILD_MODNAME;
437 wg->chip.direction_input = wcove_gpio_dir_in;
438 wg->chip.direction_output = wcove_gpio_dir_out;
439 wg->chip.get_direction = wcove_gpio_get_direction;
440 wg->chip.get = wcove_gpio_get;
441 wg->chip.set = wcove_gpio_set;
442 wg->chip.set_config = wcove_gpio_set_config,
443 wg->chip.base = -1;
444 wg->chip.ngpio = WCOVE_VGPIO_NUM;
445 wg->chip.can_sleep = true;
446 wg->chip.parent = pdev->dev.parent;
447 wg->chip.dbg_show = wcove_gpio_dbg_show;
448 wg->dev = dev;
449 wg->regmap = pmic->regmap;
450
451 ret = devm_gpiochip_add_data(dev, &wg->chip, wg);
452 if (ret) {
453 dev_err(dev, "Failed to add gpiochip: %d\n", ret);
454 return ret;
455 }
456
457 ret = gpiochip_irqchip_add_nested(&wg->chip, &wcove_irqchip, 0,
458 handle_simple_irq, IRQ_TYPE_NONE);
459 if (ret) {
460 dev_err(dev, "Failed to add irqchip: %d\n", ret);
461 return ret;
462 }
463
464 virq = regmap_irq_get_virq(wg->regmap_irq_chip, irq);
465 if (virq < 0) {
466 dev_err(dev, "Failed to get virq by irq %d\n", irq);
467 return virq;
468 }
469
470 ret = devm_request_threaded_irq(dev, virq, NULL,
471 wcove_gpio_irq_handler, IRQF_ONESHOT, pdev->name, wg);
472 if (ret) {
473 dev_err(dev, "Failed to request irq %d\n", virq);
474 return ret;
475 }
476
477 gpiochip_set_nested_irqchip(&wg->chip, &wcove_irqchip, virq);
478
479 /* Enable GPIO0 interrupts */
480 ret = regmap_update_bits(wg->regmap, IRQ_MASK_BASE, GPIO_IRQ0_MASK,
481 0x00);
482 if (ret)
483 return ret;
484
485 /* Enable GPIO1 interrupts */
486 ret = regmap_update_bits(wg->regmap, IRQ_MASK_BASE + 1, GPIO_IRQ1_MASK,
487 0x00);
488 if (ret)
489 return ret;
490
491 return 0;
492 }
493
494 /*
495 * Whiskey Cove PMIC itself is a analog device(but with digital control
496 * interface) providing power management support for other devices in
497 * the accompanied SoC, so we have no .pm for Whiskey Cove GPIO driver.
498 */
499 static struct platform_driver wcove_gpio_driver = {
500 .driver = {
501 .name = "bxt_wcove_gpio",
502 },
503 .probe = wcove_gpio_probe,
504 };
505
506 module_platform_driver(wcove_gpio_driver);
507
508 MODULE_AUTHOR("Ajay Thomas <ajay.thomas.david.rajamanickam@intel.com>");
509 MODULE_AUTHOR("Bin Gao <bin.gao@intel.com>");
510 MODULE_DESCRIPTION("Intel Whiskey Cove GPIO Driver");
511 MODULE_LICENSE("GPL v2");
512 MODULE_ALIAS("platform:bxt_wcove_gpio");
513