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/init.h>
9 #include <linux/platform_device.h>
10 #include <linux/slab.h>
11 #include <linux/gpio/driver.h>
12 #include <linux/interrupt.h>
13 #include <linux/of.h>
14 #include <linux/mfd/stmpe.h>
15 #include <linux/seq_file.h>
16 #include <linux/bitops.h>
17
18 /*
19 * These registers are modified under the irq bus lock and cached to avoid
20 * unnecessary writes in bus_sync_unlock.
21 */
22 enum { REG_RE, REG_FE, REG_IE };
23
24 enum { LSB, CSB, MSB };
25
26 #define CACHE_NR_REGS 3
27 /* No variant has more than 24 GPIOs */
28 #define CACHE_NR_BANKS (24 / 8)
29
30 struct stmpe_gpio {
31 struct gpio_chip chip;
32 struct stmpe *stmpe;
33 struct device *dev;
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 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 stmpe_reg_read(stmpe, stmpe->regs[STMPE_IDX_GPMR_LSB]);
203 stmpe_reg_read(stmpe, stmpe->regs[STMPE_IDX_GPMR_CSB]);
204 }
205
206 for (i = 0; i < CACHE_NR_REGS; i++) {
207 /* STMPE801 and STMPE1600 don't have RE and FE registers */
208 if ((stmpe->partnum == STMPE801 ||
209 stmpe->partnum == STMPE1600) &&
210 (i != REG_IE))
211 continue;
212
213 for (j = 0; j < num_banks; j++) {
214 u8 old = stmpe_gpio->oldregs[i][j];
215 u8 new = stmpe_gpio->regs[i][j];
216
217 if (new == old)
218 continue;
219
220 stmpe_gpio->oldregs[i][j] = new;
221 stmpe_reg_write(stmpe, stmpe->regs[regmap[i][j]], new);
222 }
223 }
224
225 mutex_unlock(&stmpe_gpio->irq_lock);
226 }
227
stmpe_gpio_irq_mask(struct irq_data * d)228 static void stmpe_gpio_irq_mask(struct irq_data *d)
229 {
230 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
231 struct stmpe_gpio *stmpe_gpio = gpiochip_get_data(gc);
232 int offset = d->hwirq;
233 int regoffset = offset / 8;
234 int mask = BIT(offset % 8);
235
236 stmpe_gpio->regs[REG_IE][regoffset] &= ~mask;
237 gpiochip_disable_irq(gc, offset);
238 }
239
stmpe_gpio_irq_unmask(struct irq_data * d)240 static void stmpe_gpio_irq_unmask(struct irq_data *d)
241 {
242 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
243 struct stmpe_gpio *stmpe_gpio = gpiochip_get_data(gc);
244 int offset = d->hwirq;
245 int regoffset = offset / 8;
246 int mask = BIT(offset % 8);
247
248 gpiochip_enable_irq(gc, offset);
249 stmpe_gpio->regs[REG_IE][regoffset] |= mask;
250 }
251
stmpe_dbg_show_one(struct seq_file * s,struct gpio_chip * gc,unsigned offset,unsigned gpio)252 static void stmpe_dbg_show_one(struct seq_file *s,
253 struct gpio_chip *gc,
254 unsigned offset, unsigned gpio)
255 {
256 struct stmpe_gpio *stmpe_gpio = gpiochip_get_data(gc);
257 struct stmpe *stmpe = stmpe_gpio->stmpe;
258 const char *label = gpiochip_is_requested(gc, offset);
259 bool val = !!stmpe_gpio_get(gc, offset);
260 u8 bank = offset / 8;
261 u8 dir_reg = stmpe->regs[STMPE_IDX_GPDR_LSB + bank];
262 u8 mask = BIT(offset % 8);
263 int ret;
264 u8 dir;
265
266 ret = stmpe_reg_read(stmpe, dir_reg);
267 if (ret < 0)
268 return;
269 dir = !!(ret & mask);
270
271 if (dir) {
272 seq_printf(s, " gpio-%-3d (%-20.20s) out %s",
273 gpio, label ?: "(none)",
274 val ? "hi" : "lo");
275 } else {
276 u8 edge_det_reg;
277 u8 rise_reg;
278 u8 fall_reg;
279 u8 irqen_reg;
280
281 static const char * const edge_det_values[] = {
282 "edge-inactive",
283 "edge-asserted",
284 "not-supported"
285 };
286 static const char * const rise_values[] = {
287 "no-rising-edge-detection",
288 "rising-edge-detection",
289 "not-supported"
290 };
291 static const char * const fall_values[] = {
292 "no-falling-edge-detection",
293 "falling-edge-detection",
294 "not-supported"
295 };
296 #define NOT_SUPPORTED_IDX 2
297 u8 edge_det = NOT_SUPPORTED_IDX;
298 u8 rise = NOT_SUPPORTED_IDX;
299 u8 fall = NOT_SUPPORTED_IDX;
300 bool irqen;
301
302 switch (stmpe->partnum) {
303 case STMPE610:
304 case STMPE811:
305 case STMPE1601:
306 case STMPE2401:
307 case STMPE2403:
308 edge_det_reg = stmpe->regs[STMPE_IDX_GPEDR_LSB + bank];
309 ret = stmpe_reg_read(stmpe, edge_det_reg);
310 if (ret < 0)
311 return;
312 edge_det = !!(ret & mask);
313 fallthrough;
314 case STMPE1801:
315 rise_reg = stmpe->regs[STMPE_IDX_GPRER_LSB + bank];
316 fall_reg = stmpe->regs[STMPE_IDX_GPFER_LSB + bank];
317
318 ret = stmpe_reg_read(stmpe, rise_reg);
319 if (ret < 0)
320 return;
321 rise = !!(ret & mask);
322 ret = stmpe_reg_read(stmpe, fall_reg);
323 if (ret < 0)
324 return;
325 fall = !!(ret & mask);
326 fallthrough;
327 case STMPE801:
328 case STMPE1600:
329 irqen_reg = stmpe->regs[STMPE_IDX_IEGPIOR_LSB + bank];
330 break;
331
332 default:
333 return;
334 }
335
336 ret = stmpe_reg_read(stmpe, irqen_reg);
337 if (ret < 0)
338 return;
339 irqen = !!(ret & mask);
340
341 seq_printf(s, " gpio-%-3d (%-20.20s) in %s %13s %13s %25s %25s",
342 gpio, label ?: "(none)",
343 val ? "hi" : "lo",
344 edge_det_values[edge_det],
345 irqen ? "IRQ-enabled" : "IRQ-disabled",
346 rise_values[rise],
347 fall_values[fall]);
348 }
349 }
350
stmpe_dbg_show(struct seq_file * s,struct gpio_chip * gc)351 static void stmpe_dbg_show(struct seq_file *s, struct gpio_chip *gc)
352 {
353 unsigned i;
354 unsigned gpio = gc->base;
355
356 for (i = 0; i < gc->ngpio; i++, gpio++) {
357 stmpe_dbg_show_one(s, gc, i, gpio);
358 seq_putc(s, '\n');
359 }
360 }
361
362 static const struct irq_chip stmpe_gpio_irq_chip = {
363 .name = "stmpe-gpio",
364 .irq_bus_lock = stmpe_gpio_irq_lock,
365 .irq_bus_sync_unlock = stmpe_gpio_irq_sync_unlock,
366 .irq_mask = stmpe_gpio_irq_mask,
367 .irq_unmask = stmpe_gpio_irq_unmask,
368 .irq_set_type = stmpe_gpio_irq_set_type,
369 .flags = IRQCHIP_IMMUTABLE,
370 GPIOCHIP_IRQ_RESOURCE_HELPERS,
371 };
372
373 #define MAX_GPIOS 24
374
stmpe_gpio_irq(int irq,void * dev)375 static irqreturn_t stmpe_gpio_irq(int irq, void *dev)
376 {
377 struct stmpe_gpio *stmpe_gpio = dev;
378 struct stmpe *stmpe = stmpe_gpio->stmpe;
379 u8 statmsbreg;
380 int num_banks = DIV_ROUND_UP(stmpe->num_gpios, 8);
381 u8 status[DIV_ROUND_UP(MAX_GPIOS, 8)];
382 int ret;
383 int i;
384
385 /*
386 * the stmpe_block_read() call below, imposes to set statmsbreg
387 * with the register located at the lowest address. As STMPE1600
388 * variant is the only one which respect registers address's order
389 * (LSB regs located at lowest address than MSB ones) whereas all
390 * the others have a registers layout with MSB located before the
391 * LSB regs.
392 */
393 if (stmpe->partnum == STMPE1600)
394 statmsbreg = stmpe->regs[STMPE_IDX_ISGPIOR_LSB];
395 else
396 statmsbreg = stmpe->regs[STMPE_IDX_ISGPIOR_MSB];
397
398 ret = stmpe_block_read(stmpe, statmsbreg, num_banks, status);
399 if (ret < 0)
400 return IRQ_NONE;
401
402 for (i = 0; i < num_banks; i++) {
403 int bank = (stmpe_gpio->stmpe->partnum == STMPE1600) ? i :
404 num_banks - i - 1;
405 unsigned int enabled = stmpe_gpio->regs[REG_IE][bank];
406 unsigned int stat = status[i];
407
408 stat &= enabled;
409 if (!stat)
410 continue;
411
412 while (stat) {
413 int bit = __ffs(stat);
414 int line = bank * 8 + bit;
415 int child_irq = irq_find_mapping(stmpe_gpio->chip.irq.domain,
416 line);
417
418 handle_nested_irq(child_irq);
419 stat &= ~BIT(bit);
420 }
421
422 /*
423 * interrupt status register write has no effect on
424 * 801/1801/1600, bits are cleared when read.
425 * Edge detect register is not present on 801/1600/1801
426 */
427 if (stmpe->partnum != STMPE801 && stmpe->partnum != STMPE1600 &&
428 stmpe->partnum != STMPE1801) {
429 stmpe_reg_write(stmpe, statmsbreg + i, status[i]);
430 stmpe_reg_write(stmpe,
431 stmpe->regs[STMPE_IDX_GPEDR_MSB] + i,
432 status[i]);
433 }
434 }
435
436 return IRQ_HANDLED;
437 }
438
stmpe_init_irq_valid_mask(struct gpio_chip * gc,unsigned long * valid_mask,unsigned int ngpios)439 static void stmpe_init_irq_valid_mask(struct gpio_chip *gc,
440 unsigned long *valid_mask,
441 unsigned int ngpios)
442 {
443 struct stmpe_gpio *stmpe_gpio = gpiochip_get_data(gc);
444 int i;
445
446 if (!stmpe_gpio->norequest_mask)
447 return;
448
449 /* Forbid unused lines to be mapped as IRQs */
450 for (i = 0; i < sizeof(u32); i++) {
451 if (stmpe_gpio->norequest_mask & BIT(i))
452 clear_bit(i, valid_mask);
453 }
454 }
455
stmpe_gpio_disable(void * stmpe)456 static void stmpe_gpio_disable(void *stmpe)
457 {
458 stmpe_disable(stmpe, STMPE_BLOCK_GPIO);
459 }
460
stmpe_gpio_probe(struct platform_device * pdev)461 static int stmpe_gpio_probe(struct platform_device *pdev)
462 {
463 struct stmpe *stmpe = dev_get_drvdata(pdev->dev.parent);
464 struct device_node *np = pdev->dev.of_node;
465 struct stmpe_gpio *stmpe_gpio;
466 int ret, irq;
467
468 if (stmpe->num_gpios > MAX_GPIOS) {
469 dev_err(&pdev->dev, "Need to increase maximum GPIO number\n");
470 return -EINVAL;
471 }
472
473 stmpe_gpio = devm_kzalloc(&pdev->dev, sizeof(*stmpe_gpio), GFP_KERNEL);
474 if (!stmpe_gpio)
475 return -ENOMEM;
476
477 mutex_init(&stmpe_gpio->irq_lock);
478
479 stmpe_gpio->dev = &pdev->dev;
480 stmpe_gpio->stmpe = stmpe;
481 stmpe_gpio->chip = template_chip;
482 stmpe_gpio->chip.ngpio = stmpe->num_gpios;
483 stmpe_gpio->chip.parent = &pdev->dev;
484 stmpe_gpio->chip.base = -1;
485
486 if (IS_ENABLED(CONFIG_DEBUG_FS))
487 stmpe_gpio->chip.dbg_show = stmpe_dbg_show;
488
489 of_property_read_u32(np, "st,norequest-mask",
490 &stmpe_gpio->norequest_mask);
491
492 irq = platform_get_irq(pdev, 0);
493 if (irq < 0)
494 dev_info(&pdev->dev,
495 "device configured in no-irq mode: "
496 "irqs are not available\n");
497
498 ret = stmpe_enable(stmpe, STMPE_BLOCK_GPIO);
499 if (ret)
500 return ret;
501
502 ret = devm_add_action_or_reset(&pdev->dev, stmpe_gpio_disable, stmpe);
503 if (ret)
504 return ret;
505
506 if (irq > 0) {
507 struct gpio_irq_chip *girq;
508
509 ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
510 stmpe_gpio_irq, IRQF_ONESHOT,
511 "stmpe-gpio", stmpe_gpio);
512 if (ret) {
513 dev_err(&pdev->dev, "unable to get irq: %d\n", ret);
514 return ret;
515 }
516
517 girq = &stmpe_gpio->chip.irq;
518 gpio_irq_chip_set_chip(girq, &stmpe_gpio_irq_chip);
519 /* This will let us handle the parent IRQ in the driver */
520 girq->parent_handler = NULL;
521 girq->num_parents = 0;
522 girq->parents = NULL;
523 girq->default_type = IRQ_TYPE_NONE;
524 girq->handler = handle_simple_irq;
525 girq->threaded = true;
526 girq->init_valid_mask = stmpe_init_irq_valid_mask;
527 }
528
529 return devm_gpiochip_add_data(&pdev->dev, &stmpe_gpio->chip, stmpe_gpio);
530 }
531
532 static struct platform_driver stmpe_gpio_driver = {
533 .driver = {
534 .suppress_bind_attrs = true,
535 .name = "stmpe-gpio",
536 },
537 .probe = stmpe_gpio_probe,
538 };
539
stmpe_gpio_init(void)540 static int __init stmpe_gpio_init(void)
541 {
542 return platform_driver_register(&stmpe_gpio_driver);
543 }
544 subsys_initcall(stmpe_gpio_init);
545