1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) ST-Ericsson SA 2010
4 *
5 * Author: Rabin Vincent <rabin.vincent@stericsson.com> for ST-Ericsson
6 */
7
8 #include <linux/bitops.h>
9 #include <linux/cleanup.h>
10 #include <linux/gpio/driver.h>
11 #include <linux/init.h>
12 #include <linux/interrupt.h>
13 #include <linux/mfd/stmpe.h>
14 #include <linux/property.h>
15 #include <linux/platform_device.h>
16 #include <linux/seq_file.h>
17 #include <linux/slab.h>
18
19 /*
20 * These registers are modified under the irq bus lock and cached to avoid
21 * unnecessary writes in bus_sync_unlock.
22 */
23 enum { REG_RE, REG_FE, REG_IE };
24
25 enum { LSB, CSB, MSB };
26
27 #define CACHE_NR_REGS 3
28 /* No variant has more than 24 GPIOs */
29 #define CACHE_NR_BANKS (24 / 8)
30
31 struct stmpe_gpio {
32 struct gpio_chip chip;
33 struct stmpe *stmpe;
34 struct mutex irq_lock;
35 u32 norequest_mask;
36 /* Caches of interrupt control registers for bus_lock */
37 u8 regs[CACHE_NR_REGS][CACHE_NR_BANKS];
38 u8 oldregs[CACHE_NR_REGS][CACHE_NR_BANKS];
39 };
40
stmpe_gpio_get(struct gpio_chip * chip,unsigned offset)41 static int stmpe_gpio_get(struct gpio_chip *chip, unsigned offset)
42 {
43 struct stmpe_gpio *stmpe_gpio = gpiochip_get_data(chip);
44 struct stmpe *stmpe = stmpe_gpio->stmpe;
45 u8 reg = stmpe->regs[STMPE_IDX_GPMR_LSB + (offset / 8)];
46 u8 mask = BIT(offset % 8);
47 int ret;
48
49 ret = stmpe_reg_read(stmpe, reg);
50 if (ret < 0)
51 return ret;
52
53 return !!(ret & mask);
54 }
55
stmpe_gpio_set(struct gpio_chip * chip,unsigned offset,int val)56 static void stmpe_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
57 {
58 struct stmpe_gpio *stmpe_gpio = gpiochip_get_data(chip);
59 struct stmpe *stmpe = stmpe_gpio->stmpe;
60 int which = val ? STMPE_IDX_GPSR_LSB : STMPE_IDX_GPCR_LSB;
61 u8 reg = stmpe->regs[which + (offset / 8)];
62 u8 mask = BIT(offset % 8);
63
64 /*
65 * Some variants have single register for gpio set/clear functionality.
66 * For them we need to write 0 to clear and 1 to set.
67 */
68 if (stmpe->regs[STMPE_IDX_GPSR_LSB] == stmpe->regs[STMPE_IDX_GPCR_LSB])
69 stmpe_set_bits(stmpe, reg, mask, val ? mask : 0);
70 else
71 stmpe_reg_write(stmpe, reg, mask);
72 }
73
stmpe_gpio_get_direction(struct gpio_chip * chip,unsigned offset)74 static int stmpe_gpio_get_direction(struct gpio_chip *chip,
75 unsigned offset)
76 {
77 struct stmpe_gpio *stmpe_gpio = gpiochip_get_data(chip);
78 struct stmpe *stmpe = stmpe_gpio->stmpe;
79 u8 reg = stmpe->regs[STMPE_IDX_GPDR_LSB] - (offset / 8);
80 u8 mask = BIT(offset % 8);
81 int ret;
82
83 ret = stmpe_reg_read(stmpe, reg);
84 if (ret < 0)
85 return ret;
86
87 if (ret & mask)
88 return GPIO_LINE_DIRECTION_OUT;
89
90 return GPIO_LINE_DIRECTION_IN;
91 }
92
stmpe_gpio_direction_output(struct gpio_chip * chip,unsigned offset,int val)93 static int stmpe_gpio_direction_output(struct gpio_chip *chip,
94 unsigned offset, int val)
95 {
96 struct stmpe_gpio *stmpe_gpio = gpiochip_get_data(chip);
97 struct stmpe *stmpe = stmpe_gpio->stmpe;
98 u8 reg = stmpe->regs[STMPE_IDX_GPDR_LSB + (offset / 8)];
99 u8 mask = BIT(offset % 8);
100
101 stmpe_gpio_set(chip, offset, val);
102
103 return stmpe_set_bits(stmpe, reg, mask, mask);
104 }
105
stmpe_gpio_direction_input(struct gpio_chip * chip,unsigned offset)106 static int stmpe_gpio_direction_input(struct gpio_chip *chip,
107 unsigned offset)
108 {
109 struct stmpe_gpio *stmpe_gpio = gpiochip_get_data(chip);
110 struct stmpe *stmpe = stmpe_gpio->stmpe;
111 u8 reg = stmpe->regs[STMPE_IDX_GPDR_LSB + (offset / 8)];
112 u8 mask = BIT(offset % 8);
113
114 return stmpe_set_bits(stmpe, reg, mask, 0);
115 }
116
stmpe_gpio_request(struct gpio_chip * chip,unsigned offset)117 static int stmpe_gpio_request(struct gpio_chip *chip, unsigned offset)
118 {
119 struct stmpe_gpio *stmpe_gpio = gpiochip_get_data(chip);
120 struct stmpe *stmpe = stmpe_gpio->stmpe;
121
122 if (stmpe_gpio->norequest_mask & BIT(offset))
123 return -EINVAL;
124
125 return stmpe_set_altfunc(stmpe, BIT(offset), STMPE_BLOCK_GPIO);
126 }
127
128 static const struct gpio_chip template_chip = {
129 .label = "stmpe",
130 .owner = THIS_MODULE,
131 .get_direction = stmpe_gpio_get_direction,
132 .direction_input = stmpe_gpio_direction_input,
133 .get = stmpe_gpio_get,
134 .direction_output = stmpe_gpio_direction_output,
135 .set = stmpe_gpio_set,
136 .request = stmpe_gpio_request,
137 .can_sleep = true,
138 };
139
stmpe_gpio_irq_set_type(struct irq_data * d,unsigned int type)140 static int stmpe_gpio_irq_set_type(struct irq_data *d, unsigned int type)
141 {
142 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
143 struct stmpe_gpio *stmpe_gpio = gpiochip_get_data(gc);
144 int offset = d->hwirq;
145 int regoffset = offset / 8;
146 int mask = BIT(offset % 8);
147
148 if (type & IRQ_TYPE_LEVEL_LOW || type & IRQ_TYPE_LEVEL_HIGH)
149 return -EINVAL;
150
151 /* STMPE801 and STMPE 1600 don't have RE and FE registers */
152 if (stmpe_gpio->stmpe->partnum == STMPE801 ||
153 stmpe_gpio->stmpe->partnum == STMPE1600)
154 return 0;
155
156 if (type & IRQ_TYPE_EDGE_RISING)
157 stmpe_gpio->regs[REG_RE][regoffset] |= mask;
158 else
159 stmpe_gpio->regs[REG_RE][regoffset] &= ~mask;
160
161 if (type & IRQ_TYPE_EDGE_FALLING)
162 stmpe_gpio->regs[REG_FE][regoffset] |= mask;
163 else
164 stmpe_gpio->regs[REG_FE][regoffset] &= ~mask;
165
166 return 0;
167 }
168
stmpe_gpio_irq_lock(struct irq_data * d)169 static void stmpe_gpio_irq_lock(struct irq_data *d)
170 {
171 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
172 struct stmpe_gpio *stmpe_gpio = gpiochip_get_data(gc);
173
174 mutex_lock(&stmpe_gpio->irq_lock);
175 }
176
stmpe_gpio_irq_sync_unlock(struct irq_data * d)177 static void stmpe_gpio_irq_sync_unlock(struct irq_data *d)
178 {
179 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
180 struct stmpe_gpio *stmpe_gpio = gpiochip_get_data(gc);
181 struct stmpe *stmpe = stmpe_gpio->stmpe;
182 int num_banks = DIV_ROUND_UP(stmpe->num_gpios, 8);
183 static const u8 regmap[CACHE_NR_REGS][CACHE_NR_BANKS] = {
184 [REG_RE][LSB] = STMPE_IDX_GPRER_LSB,
185 [REG_RE][CSB] = STMPE_IDX_GPRER_CSB,
186 [REG_RE][MSB] = STMPE_IDX_GPRER_MSB,
187 [REG_FE][LSB] = STMPE_IDX_GPFER_LSB,
188 [REG_FE][CSB] = STMPE_IDX_GPFER_CSB,
189 [REG_FE][MSB] = STMPE_IDX_GPFER_MSB,
190 [REG_IE][LSB] = STMPE_IDX_IEGPIOR_LSB,
191 [REG_IE][CSB] = STMPE_IDX_IEGPIOR_CSB,
192 [REG_IE][MSB] = STMPE_IDX_IEGPIOR_MSB,
193 };
194 int ret, i, j;
195
196 /*
197 * STMPE1600: to be able to get IRQ from pins,
198 * a read must be done on GPMR register, or a write in
199 * GPSR or GPCR registers
200 */
201 if (stmpe->partnum == STMPE1600) {
202 ret = stmpe_reg_read(stmpe, stmpe->regs[STMPE_IDX_GPMR_LSB]);
203 if (ret < 0) {
204 dev_err(stmpe->dev, "Failed to read GPMR_LSB: %d\n", ret);
205 goto err;
206 }
207 ret = stmpe_reg_read(stmpe, stmpe->regs[STMPE_IDX_GPMR_CSB]);
208 if (ret < 0) {
209 dev_err(stmpe->dev, "Failed to read GPMR_CSB: %d\n", ret);
210 goto err;
211 }
212 }
213
214 for (i = 0; i < CACHE_NR_REGS; i++) {
215 /* STMPE801 and STMPE1600 don't have RE and FE registers */
216 if ((stmpe->partnum == STMPE801 ||
217 stmpe->partnum == STMPE1600) &&
218 (i != REG_IE))
219 continue;
220
221 for (j = 0; j < num_banks; j++) {
222 u8 old = stmpe_gpio->oldregs[i][j];
223 u8 new = stmpe_gpio->regs[i][j];
224
225 if (new == old)
226 continue;
227
228 stmpe_gpio->oldregs[i][j] = new;
229 stmpe_reg_write(stmpe, stmpe->regs[regmap[i][j]], new);
230 }
231 }
232
233 err:
234 mutex_unlock(&stmpe_gpio->irq_lock);
235 }
236
stmpe_gpio_irq_mask(struct irq_data * d)237 static void stmpe_gpio_irq_mask(struct irq_data *d)
238 {
239 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
240 struct stmpe_gpio *stmpe_gpio = gpiochip_get_data(gc);
241 int offset = d->hwirq;
242 int regoffset = offset / 8;
243 int mask = BIT(offset % 8);
244
245 stmpe_gpio->regs[REG_IE][regoffset] &= ~mask;
246 gpiochip_disable_irq(gc, offset);
247 }
248
stmpe_gpio_irq_unmask(struct irq_data * d)249 static void stmpe_gpio_irq_unmask(struct irq_data *d)
250 {
251 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
252 struct stmpe_gpio *stmpe_gpio = gpiochip_get_data(gc);
253 int offset = d->hwirq;
254 int regoffset = offset / 8;
255 int mask = BIT(offset % 8);
256
257 gpiochip_enable_irq(gc, offset);
258 stmpe_gpio->regs[REG_IE][regoffset] |= mask;
259 }
260
stmpe_dbg_show_one(struct seq_file * s,struct gpio_chip * gc,unsigned offset,unsigned gpio)261 static void stmpe_dbg_show_one(struct seq_file *s,
262 struct gpio_chip *gc,
263 unsigned offset, unsigned gpio)
264 {
265 struct stmpe_gpio *stmpe_gpio = gpiochip_get_data(gc);
266 struct stmpe *stmpe = stmpe_gpio->stmpe;
267 bool val = !!stmpe_gpio_get(gc, offset);
268 u8 bank = offset / 8;
269 u8 dir_reg = stmpe->regs[STMPE_IDX_GPDR_LSB + bank];
270 u8 mask = BIT(offset % 8);
271 int ret;
272 u8 dir;
273
274 char *label __free(kfree) = gpiochip_dup_line_label(gc, offset);
275 if (IS_ERR(label))
276 return;
277
278 ret = stmpe_reg_read(stmpe, dir_reg);
279 if (ret < 0)
280 return;
281 dir = !!(ret & mask);
282
283 if (dir) {
284 seq_printf(s, " gpio-%-3d (%-20.20s) out %s",
285 gpio, label ?: "(none)",
286 val ? "hi" : "lo");
287 } else {
288 u8 edge_det_reg;
289 u8 rise_reg;
290 u8 fall_reg;
291 u8 irqen_reg;
292
293 static const char * const edge_det_values[] = {
294 "edge-inactive",
295 "edge-asserted",
296 "not-supported"
297 };
298 static const char * const rise_values[] = {
299 "no-rising-edge-detection",
300 "rising-edge-detection",
301 "not-supported"
302 };
303 static const char * const fall_values[] = {
304 "no-falling-edge-detection",
305 "falling-edge-detection",
306 "not-supported"
307 };
308 #define NOT_SUPPORTED_IDX 2
309 u8 edge_det = NOT_SUPPORTED_IDX;
310 u8 rise = NOT_SUPPORTED_IDX;
311 u8 fall = NOT_SUPPORTED_IDX;
312 bool irqen;
313
314 switch (stmpe->partnum) {
315 case STMPE610:
316 case STMPE811:
317 case STMPE1601:
318 case STMPE2401:
319 case STMPE2403:
320 edge_det_reg = stmpe->regs[STMPE_IDX_GPEDR_LSB + bank];
321 ret = stmpe_reg_read(stmpe, edge_det_reg);
322 if (ret < 0)
323 return;
324 edge_det = !!(ret & mask);
325 fallthrough;
326 case STMPE1801:
327 rise_reg = stmpe->regs[STMPE_IDX_GPRER_LSB + bank];
328 fall_reg = stmpe->regs[STMPE_IDX_GPFER_LSB + bank];
329
330 ret = stmpe_reg_read(stmpe, rise_reg);
331 if (ret < 0)
332 return;
333 rise = !!(ret & mask);
334 ret = stmpe_reg_read(stmpe, fall_reg);
335 if (ret < 0)
336 return;
337 fall = !!(ret & mask);
338 fallthrough;
339 case STMPE801:
340 case STMPE1600:
341 irqen_reg = stmpe->regs[STMPE_IDX_IEGPIOR_LSB + bank];
342 break;
343
344 default:
345 return;
346 }
347
348 ret = stmpe_reg_read(stmpe, irqen_reg);
349 if (ret < 0)
350 return;
351 irqen = !!(ret & mask);
352
353 seq_printf(s, " gpio-%-3d (%-20.20s) in %s %13s %13s %25s %25s",
354 gpio, label ?: "(none)",
355 val ? "hi" : "lo",
356 edge_det_values[edge_det],
357 irqen ? "IRQ-enabled" : "IRQ-disabled",
358 rise_values[rise],
359 fall_values[fall]);
360 }
361 }
362
stmpe_dbg_show(struct seq_file * s,struct gpio_chip * gc)363 static void stmpe_dbg_show(struct seq_file *s, struct gpio_chip *gc)
364 {
365 unsigned i;
366 unsigned gpio = gc->base;
367
368 for (i = 0; i < gc->ngpio; i++, gpio++) {
369 stmpe_dbg_show_one(s, gc, i, gpio);
370 seq_putc(s, '\n');
371 }
372 }
373
374 static const struct irq_chip stmpe_gpio_irq_chip = {
375 .name = "stmpe-gpio",
376 .irq_bus_lock = stmpe_gpio_irq_lock,
377 .irq_bus_sync_unlock = stmpe_gpio_irq_sync_unlock,
378 .irq_mask = stmpe_gpio_irq_mask,
379 .irq_unmask = stmpe_gpio_irq_unmask,
380 .irq_set_type = stmpe_gpio_irq_set_type,
381 .flags = IRQCHIP_IMMUTABLE,
382 GPIOCHIP_IRQ_RESOURCE_HELPERS,
383 };
384
385 #define MAX_GPIOS 24
386
stmpe_gpio_irq(int irq,void * dev)387 static irqreturn_t stmpe_gpio_irq(int irq, void *dev)
388 {
389 struct stmpe_gpio *stmpe_gpio = dev;
390 struct stmpe *stmpe = stmpe_gpio->stmpe;
391 u8 statmsbreg;
392 int num_banks = DIV_ROUND_UP(stmpe->num_gpios, 8);
393 u8 status[DIV_ROUND_UP(MAX_GPIOS, 8)];
394 int ret;
395 int i;
396
397 /*
398 * the stmpe_block_read() call below, imposes to set statmsbreg
399 * with the register located at the lowest address. As STMPE1600
400 * variant is the only one which respect registers address's order
401 * (LSB regs located at lowest address than MSB ones) whereas all
402 * the others have a registers layout with MSB located before the
403 * LSB regs.
404 */
405 if (stmpe->partnum == STMPE1600)
406 statmsbreg = stmpe->regs[STMPE_IDX_ISGPIOR_LSB];
407 else
408 statmsbreg = stmpe->regs[STMPE_IDX_ISGPIOR_MSB];
409
410 ret = stmpe_block_read(stmpe, statmsbreg, num_banks, status);
411 if (ret < 0)
412 return IRQ_NONE;
413
414 for (i = 0; i < num_banks; i++) {
415 int bank = (stmpe_gpio->stmpe->partnum == STMPE1600) ? i :
416 num_banks - i - 1;
417 unsigned int enabled = stmpe_gpio->regs[REG_IE][bank];
418 unsigned int stat = status[i];
419
420 stat &= enabled;
421 if (!stat)
422 continue;
423
424 while (stat) {
425 int bit = __ffs(stat);
426 int line = bank * 8 + bit;
427 int child_irq = irq_find_mapping(stmpe_gpio->chip.irq.domain,
428 line);
429
430 handle_nested_irq(child_irq);
431 stat &= ~BIT(bit);
432 }
433
434 /*
435 * interrupt status register write has no effect on
436 * 801/1801/1600, bits are cleared when read.
437 * Edge detect register is not present on 801/1600/1801
438 */
439 if (stmpe->partnum != STMPE801 && stmpe->partnum != STMPE1600 &&
440 stmpe->partnum != STMPE1801) {
441 stmpe_reg_write(stmpe, statmsbreg + i, status[i]);
442 stmpe_reg_write(stmpe,
443 stmpe->regs[STMPE_IDX_GPEDR_MSB] + i,
444 status[i]);
445 }
446 }
447
448 return IRQ_HANDLED;
449 }
450
stmpe_init_irq_valid_mask(struct gpio_chip * gc,unsigned long * valid_mask,unsigned int ngpios)451 static void stmpe_init_irq_valid_mask(struct gpio_chip *gc,
452 unsigned long *valid_mask,
453 unsigned int ngpios)
454 {
455 struct stmpe_gpio *stmpe_gpio = gpiochip_get_data(gc);
456 int i;
457
458 if (!stmpe_gpio->norequest_mask)
459 return;
460
461 /* Forbid unused lines to be mapped as IRQs */
462 for (i = 0; i < sizeof(u32); i++) {
463 if (stmpe_gpio->norequest_mask & BIT(i))
464 clear_bit(i, valid_mask);
465 }
466 }
467
stmpe_gpio_disable(void * stmpe)468 static void stmpe_gpio_disable(void *stmpe)
469 {
470 stmpe_disable(stmpe, STMPE_BLOCK_GPIO);
471 }
472
stmpe_gpio_probe(struct platform_device * pdev)473 static int stmpe_gpio_probe(struct platform_device *pdev)
474 {
475 struct device *dev = &pdev->dev;
476 struct stmpe *stmpe = dev_get_drvdata(dev->parent);
477 struct stmpe_gpio *stmpe_gpio;
478 int ret, irq;
479
480 if (stmpe->num_gpios > MAX_GPIOS) {
481 dev_err(dev, "Need to increase maximum GPIO number\n");
482 return -EINVAL;
483 }
484
485 stmpe_gpio = devm_kzalloc(dev, sizeof(*stmpe_gpio), GFP_KERNEL);
486 if (!stmpe_gpio)
487 return -ENOMEM;
488
489 mutex_init(&stmpe_gpio->irq_lock);
490
491 stmpe_gpio->stmpe = stmpe;
492 stmpe_gpio->chip = template_chip;
493 stmpe_gpio->chip.ngpio = stmpe->num_gpios;
494 stmpe_gpio->chip.parent = dev;
495 stmpe_gpio->chip.base = -1;
496
497 if (IS_ENABLED(CONFIG_DEBUG_FS))
498 stmpe_gpio->chip.dbg_show = stmpe_dbg_show;
499
500 device_property_read_u32(dev, "st,norequest-mask", &stmpe_gpio->norequest_mask);
501
502 ret = stmpe_enable(stmpe, STMPE_BLOCK_GPIO);
503 if (ret)
504 return ret;
505
506 ret = devm_add_action_or_reset(dev, stmpe_gpio_disable, stmpe);
507 if (ret)
508 return ret;
509
510 irq = platform_get_irq(pdev, 0);
511 if (irq > 0) {
512 struct gpio_irq_chip *girq;
513
514 ret = devm_request_threaded_irq(dev, irq, NULL, stmpe_gpio_irq,
515 IRQF_ONESHOT, "stmpe-gpio", stmpe_gpio);
516 if (ret)
517 return dev_err_probe(dev, ret, "unable to register IRQ handler\n");
518
519 girq = &stmpe_gpio->chip.irq;
520 gpio_irq_chip_set_chip(girq, &stmpe_gpio_irq_chip);
521 /* This will let us handle the parent IRQ in the driver */
522 girq->parent_handler = NULL;
523 girq->num_parents = 0;
524 girq->parents = NULL;
525 girq->default_type = IRQ_TYPE_NONE;
526 girq->handler = handle_simple_irq;
527 girq->threaded = true;
528 girq->init_valid_mask = stmpe_init_irq_valid_mask;
529 }
530
531 return devm_gpiochip_add_data(dev, &stmpe_gpio->chip, stmpe_gpio);
532 }
533
534 static struct platform_driver stmpe_gpio_driver = {
535 .driver = {
536 .suppress_bind_attrs = true,
537 .name = "stmpe-gpio",
538 },
539 .probe = stmpe_gpio_probe,
540 };
541
stmpe_gpio_init(void)542 static int __init stmpe_gpio_init(void)
543 {
544 return platform_driver_register(&stmpe_gpio_driver);
545 }
546 subsys_initcall(stmpe_gpio_init);
547