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9#include <linux/gpio/driver.h>
10#include <linux/i2c.h>
11#include <linux/interrupt.h>
12#include <linux/module.h>
13#include <linux/of_irq.h>
14#include <linux/seq_file.h>
15#include <linux/slab.h>
16
17#define GPIO_DDR(gpio) (0x00 << (gpio)->reg_shift)
18#define GPIO_PLR(gpio) (0x01 << (gpio)->reg_shift)
19#define GPIO_IER(gpio) (0x02 << (gpio)->reg_shift)
20#define GPIO_ISR(gpio) (0x03 << (gpio)->reg_shift)
21#define GPIO_PTR(gpio) (0x04 << (gpio)->reg_shift)
22
23struct adnp {
24 struct i2c_client *client;
25 struct gpio_chip gpio;
26 unsigned int reg_shift;
27
28 struct mutex i2c_lock;
29 struct mutex irq_lock;
30
31 u8 *irq_enable;
32 u8 *irq_level;
33 u8 *irq_rise;
34 u8 *irq_fall;
35 u8 *irq_high;
36 u8 *irq_low;
37};
38
39static int adnp_read(struct adnp *adnp, unsigned offset, uint8_t *value)
40{
41 int err;
42
43 err = i2c_smbus_read_byte_data(adnp->client, offset);
44 if (err < 0) {
45 dev_err(adnp->gpio.parent, "%s failed: %d\n",
46 "i2c_smbus_read_byte_data()", err);
47 return err;
48 }
49
50 *value = err;
51 return 0;
52}
53
54static int adnp_write(struct adnp *adnp, unsigned offset, uint8_t value)
55{
56 int err;
57
58 err = i2c_smbus_write_byte_data(adnp->client, offset, value);
59 if (err < 0) {
60 dev_err(adnp->gpio.parent, "%s failed: %d\n",
61 "i2c_smbus_write_byte_data()", err);
62 return err;
63 }
64
65 return 0;
66}
67
68static int adnp_gpio_get(struct gpio_chip *chip, unsigned offset)
69{
70 struct adnp *adnp = gpiochip_get_data(chip);
71 unsigned int reg = offset >> adnp->reg_shift;
72 unsigned int pos = offset & 7;
73 u8 value;
74 int err;
75
76 err = adnp_read(adnp, GPIO_PLR(adnp) + reg, &value);
77 if (err < 0)
78 return err;
79
80 return (value & BIT(pos)) ? 1 : 0;
81}
82
83static void __adnp_gpio_set(struct adnp *adnp, unsigned offset, int value)
84{
85 unsigned int reg = offset >> adnp->reg_shift;
86 unsigned int pos = offset & 7;
87 int err;
88 u8 val;
89
90 err = adnp_read(adnp, GPIO_PLR(adnp) + reg, &val);
91 if (err < 0)
92 return;
93
94 if (value)
95 val |= BIT(pos);
96 else
97 val &= ~BIT(pos);
98
99 adnp_write(adnp, GPIO_PLR(adnp) + reg, val);
100}
101
102static void adnp_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
103{
104 struct adnp *adnp = gpiochip_get_data(chip);
105
106 mutex_lock(&adnp->i2c_lock);
107 __adnp_gpio_set(adnp, offset, value);
108 mutex_unlock(&adnp->i2c_lock);
109}
110
111static int adnp_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
112{
113 struct adnp *adnp = gpiochip_get_data(chip);
114 unsigned int reg = offset >> adnp->reg_shift;
115 unsigned int pos = offset & 7;
116 u8 value;
117 int err;
118
119 mutex_lock(&adnp->i2c_lock);
120
121 err = adnp_read(adnp, GPIO_DDR(adnp) + reg, &value);
122 if (err < 0)
123 goto out;
124
125 value &= ~BIT(pos);
126
127 err = adnp_write(adnp, GPIO_DDR(adnp) + reg, value);
128 if (err < 0)
129 goto out;
130
131 err = adnp_read(adnp, GPIO_DDR(adnp) + reg, &value);
132 if (err < 0)
133 goto out;
134
135 if (err & BIT(pos))
136 err = -EACCES;
137
138 err = 0;
139
140out:
141 mutex_unlock(&adnp->i2c_lock);
142 return err;
143}
144
145static int adnp_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
146 int value)
147{
148 struct adnp *adnp = gpiochip_get_data(chip);
149 unsigned int reg = offset >> adnp->reg_shift;
150 unsigned int pos = offset & 7;
151 int err;
152 u8 val;
153
154 mutex_lock(&adnp->i2c_lock);
155
156 err = adnp_read(adnp, GPIO_DDR(adnp) + reg, &val);
157 if (err < 0)
158 goto out;
159
160 val |= BIT(pos);
161
162 err = adnp_write(adnp, GPIO_DDR(adnp) + reg, val);
163 if (err < 0)
164 goto out;
165
166 err = adnp_read(adnp, GPIO_DDR(adnp) + reg, &val);
167 if (err < 0)
168 goto out;
169
170 if (!(val & BIT(pos))) {
171 err = -EPERM;
172 goto out;
173 }
174
175 __adnp_gpio_set(adnp, offset, value);
176 err = 0;
177
178out:
179 mutex_unlock(&adnp->i2c_lock);
180 return err;
181}
182
183static void adnp_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
184{
185 struct adnp *adnp = gpiochip_get_data(chip);
186 unsigned int num_regs = 1 << adnp->reg_shift, i, j;
187 int err;
188
189 for (i = 0; i < num_regs; i++) {
190 u8 ddr, plr, ier, isr;
191
192 mutex_lock(&adnp->i2c_lock);
193
194 err = adnp_read(adnp, GPIO_DDR(adnp) + i, &ddr);
195 if (err < 0) {
196 mutex_unlock(&adnp->i2c_lock);
197 return;
198 }
199
200 err = adnp_read(adnp, GPIO_PLR(adnp) + i, &plr);
201 if (err < 0) {
202 mutex_unlock(&adnp->i2c_lock);
203 return;
204 }
205
206 err = adnp_read(adnp, GPIO_IER(adnp) + i, &ier);
207 if (err < 0) {
208 mutex_unlock(&adnp->i2c_lock);
209 return;
210 }
211
212 err = adnp_read(adnp, GPIO_ISR(adnp) + i, &isr);
213 if (err < 0) {
214 mutex_unlock(&adnp->i2c_lock);
215 return;
216 }
217
218 mutex_unlock(&adnp->i2c_lock);
219
220 for (j = 0; j < 8; j++) {
221 unsigned int bit = (i << adnp->reg_shift) + j;
222 const char *direction = "input ";
223 const char *level = "low ";
224 const char *interrupt = "disabled";
225 const char *pending = "";
226
227 if (ddr & BIT(j))
228 direction = "output";
229
230 if (plr & BIT(j))
231 level = "high";
232
233 if (ier & BIT(j))
234 interrupt = "enabled ";
235
236 if (isr & BIT(j))
237 pending = "pending";
238
239 seq_printf(s, "%2u: %s %s IRQ %s %s\n", bit,
240 direction, level, interrupt, pending);
241 }
242 }
243}
244
245static int adnp_gpio_setup(struct adnp *adnp, unsigned int num_gpios)
246{
247 struct gpio_chip *chip = &adnp->gpio;
248 int err;
249
250 adnp->reg_shift = get_count_order(num_gpios) - 3;
251
252 chip->direction_input = adnp_gpio_direction_input;
253 chip->direction_output = adnp_gpio_direction_output;
254 chip->get = adnp_gpio_get;
255 chip->set = adnp_gpio_set;
256 chip->can_sleep = true;
257
258 if (IS_ENABLED(CONFIG_DEBUG_FS))
259 chip->dbg_show = adnp_gpio_dbg_show;
260
261 chip->base = -1;
262 chip->ngpio = num_gpios;
263 chip->label = adnp->client->name;
264 chip->parent = &adnp->client->dev;
265 chip->of_node = chip->parent->of_node;
266 chip->owner = THIS_MODULE;
267
268 err = devm_gpiochip_add_data(&adnp->client->dev, chip, adnp);
269 if (err)
270 return err;
271
272 return 0;
273}
274
275static irqreturn_t adnp_irq(int irq, void *data)
276{
277 struct adnp *adnp = data;
278 unsigned int num_regs, i;
279
280 num_regs = 1 << adnp->reg_shift;
281
282 for (i = 0; i < num_regs; i++) {
283 unsigned int base = i << adnp->reg_shift, bit;
284 u8 changed, level, isr, ier;
285 unsigned long pending;
286 int err;
287
288 mutex_lock(&adnp->i2c_lock);
289
290 err = adnp_read(adnp, GPIO_PLR(adnp) + i, &level);
291 if (err < 0) {
292 mutex_unlock(&adnp->i2c_lock);
293 continue;
294 }
295
296 err = adnp_read(adnp, GPIO_ISR(adnp) + i, &isr);
297 if (err < 0) {
298 mutex_unlock(&adnp->i2c_lock);
299 continue;
300 }
301
302 err = adnp_read(adnp, GPIO_IER(adnp) + i, &ier);
303 if (err < 0) {
304 mutex_unlock(&adnp->i2c_lock);
305 continue;
306 }
307
308 mutex_unlock(&adnp->i2c_lock);
309
310
311 changed = level ^ adnp->irq_level[i];
312
313
314 pending = changed & ((adnp->irq_fall[i] & ~level) |
315 (adnp->irq_rise[i] & level));
316
317
318 pending |= (adnp->irq_high[i] & level) |
319 (adnp->irq_low[i] & ~level);
320
321
322 pending &= isr & ier;
323
324 for_each_set_bit(bit, &pending, 8) {
325 unsigned int child_irq;
326 child_irq = irq_find_mapping(adnp->gpio.irqdomain,
327 base + bit);
328 handle_nested_irq(child_irq);
329 }
330 }
331
332 return IRQ_HANDLED;
333}
334
335static void adnp_irq_mask(struct irq_data *d)
336{
337 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
338 struct adnp *adnp = gpiochip_get_data(gc);
339 unsigned int reg = d->hwirq >> adnp->reg_shift;
340 unsigned int pos = d->hwirq & 7;
341
342 adnp->irq_enable[reg] &= ~BIT(pos);
343}
344
345static void adnp_irq_unmask(struct irq_data *d)
346{
347 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
348 struct adnp *adnp = gpiochip_get_data(gc);
349 unsigned int reg = d->hwirq >> adnp->reg_shift;
350 unsigned int pos = d->hwirq & 7;
351
352 adnp->irq_enable[reg] |= BIT(pos);
353}
354
355static int adnp_irq_set_type(struct irq_data *d, unsigned int type)
356{
357 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
358 struct adnp *adnp = gpiochip_get_data(gc);
359 unsigned int reg = d->hwirq >> adnp->reg_shift;
360 unsigned int pos = d->hwirq & 7;
361
362 if (type & IRQ_TYPE_EDGE_RISING)
363 adnp->irq_rise[reg] |= BIT(pos);
364 else
365 adnp->irq_rise[reg] &= ~BIT(pos);
366
367 if (type & IRQ_TYPE_EDGE_FALLING)
368 adnp->irq_fall[reg] |= BIT(pos);
369 else
370 adnp->irq_fall[reg] &= ~BIT(pos);
371
372 if (type & IRQ_TYPE_LEVEL_HIGH)
373 adnp->irq_high[reg] |= BIT(pos);
374 else
375 adnp->irq_high[reg] &= ~BIT(pos);
376
377 if (type & IRQ_TYPE_LEVEL_LOW)
378 adnp->irq_low[reg] |= BIT(pos);
379 else
380 adnp->irq_low[reg] &= ~BIT(pos);
381
382 return 0;
383}
384
385static void adnp_irq_bus_lock(struct irq_data *d)
386{
387 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
388 struct adnp *adnp = gpiochip_get_data(gc);
389
390 mutex_lock(&adnp->irq_lock);
391}
392
393static void adnp_irq_bus_unlock(struct irq_data *d)
394{
395 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
396 struct adnp *adnp = gpiochip_get_data(gc);
397 unsigned int num_regs = 1 << adnp->reg_shift, i;
398
399 mutex_lock(&adnp->i2c_lock);
400
401 for (i = 0; i < num_regs; i++)
402 adnp_write(adnp, GPIO_IER(adnp) + i, adnp->irq_enable[i]);
403
404 mutex_unlock(&adnp->i2c_lock);
405 mutex_unlock(&adnp->irq_lock);
406}
407
408static struct irq_chip adnp_irq_chip = {
409 .name = "gpio-adnp",
410 .irq_mask = adnp_irq_mask,
411 .irq_unmask = adnp_irq_unmask,
412 .irq_set_type = adnp_irq_set_type,
413 .irq_bus_lock = adnp_irq_bus_lock,
414 .irq_bus_sync_unlock = adnp_irq_bus_unlock,
415};
416
417static int adnp_irq_setup(struct adnp *adnp)
418{
419 unsigned int num_regs = 1 << adnp->reg_shift, i;
420 struct gpio_chip *chip = &adnp->gpio;
421 int err;
422
423 mutex_init(&adnp->irq_lock);
424
425
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427
428
429
430
431
432
433 adnp->irq_enable = devm_kzalloc(chip->parent, num_regs * 6,
434 GFP_KERNEL);
435 if (!adnp->irq_enable)
436 return -ENOMEM;
437
438 adnp->irq_level = adnp->irq_enable + (num_regs * 1);
439 adnp->irq_rise = adnp->irq_enable + (num_regs * 2);
440 adnp->irq_fall = adnp->irq_enable + (num_regs * 3);
441 adnp->irq_high = adnp->irq_enable + (num_regs * 4);
442 adnp->irq_low = adnp->irq_enable + (num_regs * 5);
443
444 for (i = 0; i < num_regs; i++) {
445
446
447
448
449 err = adnp_read(adnp, GPIO_PLR(adnp) + i, &adnp->irq_level[i]);
450 if (err < 0)
451 return err;
452
453
454 err = adnp_write(adnp, GPIO_IER(adnp) + i, 0);
455 if (err < 0)
456 return err;
457
458 adnp->irq_enable[i] = 0x00;
459 }
460
461 err = devm_request_threaded_irq(chip->parent, adnp->client->irq,
462 NULL, adnp_irq,
463 IRQF_TRIGGER_RISING | IRQF_ONESHOT,
464 dev_name(chip->parent), adnp);
465 if (err != 0) {
466 dev_err(chip->parent, "can't request IRQ#%d: %d\n",
467 adnp->client->irq, err);
468 return err;
469 }
470
471 err = gpiochip_irqchip_add(chip,
472 &adnp_irq_chip,
473 0,
474 handle_simple_irq,
475 IRQ_TYPE_NONE);
476 if (err) {
477 dev_err(chip->parent,
478 "could not connect irqchip to gpiochip\n");
479 return err;
480 }
481
482 return 0;
483}
484
485static int adnp_i2c_probe(struct i2c_client *client,
486 const struct i2c_device_id *id)
487{
488 struct device_node *np = client->dev.of_node;
489 struct adnp *adnp;
490 u32 num_gpios;
491 int err;
492
493 err = of_property_read_u32(np, "nr-gpios", &num_gpios);
494 if (err < 0)
495 return err;
496
497 client->irq = irq_of_parse_and_map(np, 0);
498 if (!client->irq)
499 return -EPROBE_DEFER;
500
501 adnp = devm_kzalloc(&client->dev, sizeof(*adnp), GFP_KERNEL);
502 if (!adnp)
503 return -ENOMEM;
504
505 mutex_init(&adnp->i2c_lock);
506 adnp->client = client;
507
508 err = adnp_gpio_setup(adnp, num_gpios);
509 if (err)
510 return err;
511
512 if (of_find_property(np, "interrupt-controller", NULL)) {
513 err = adnp_irq_setup(adnp);
514 if (err)
515 return err;
516 }
517
518 i2c_set_clientdata(client, adnp);
519
520 return 0;
521}
522
523static const struct i2c_device_id adnp_i2c_id[] = {
524 { "gpio-adnp" },
525 { },
526};
527MODULE_DEVICE_TABLE(i2c, adnp_i2c_id);
528
529static const struct of_device_id adnp_of_match[] = {
530 { .compatible = "ad,gpio-adnp", },
531 { },
532};
533MODULE_DEVICE_TABLE(of, adnp_of_match);
534
535static struct i2c_driver adnp_i2c_driver = {
536 .driver = {
537 .name = "gpio-adnp",
538 .of_match_table = adnp_of_match,
539 },
540 .probe = adnp_i2c_probe,
541 .id_table = adnp_i2c_id,
542};
543module_i2c_driver(adnp_i2c_driver);
544
545MODULE_DESCRIPTION("Avionic Design N-bit GPIO expander");
546MODULE_AUTHOR("Thierry Reding <thierry.reding@avionic-design.de>");
547MODULE_LICENSE("GPL");
548
