1 /*
2 * GPIO Chip driver for Analog Devices
3 * ADP5588/ADP5587 I/O Expander and QWERTY Keypad Controller
4 *
5 * Copyright 2009-2010 Analog Devices Inc.
6 *
7 * Licensed under the GPL-2 or later.
8 */
9
10 #include <linux/module.h>
11 #include <linux/kernel.h>
12 #include <linux/slab.h>
13 #include <linux/init.h>
14 #include <linux/i2c.h>
15 #include <linux/gpio.h>
16 #include <linux/interrupt.h>
17 #include <linux/irq.h>
18
19 #include <linux/i2c/adp5588.h>
20
21 #define DRV_NAME "adp5588-gpio"
22
23 /*
24 * Early pre 4.0 Silicon required to delay readout by at least 25ms,
25 * since the Event Counter Register updated 25ms after the interrupt
26 * asserted.
27 */
28 #define WA_DELAYED_READOUT_REVID(rev) ((rev) < 4)
29
30 struct adp5588_gpio {
31 struct i2c_client *client;
32 struct gpio_chip gpio_chip;
33 struct mutex lock; /* protect cached dir, dat_out */
34 /* protect serialized access to the interrupt controller bus */
35 struct mutex irq_lock;
36 unsigned gpio_start;
37 unsigned irq_base;
38 uint8_t dat_out[3];
39 uint8_t dir[3];
40 uint8_t int_lvl[3];
41 uint8_t int_en[3];
42 uint8_t irq_mask[3];
43 uint8_t irq_stat[3];
44 };
45
adp5588_gpio_read(struct i2c_client * client,u8 reg)46 static int adp5588_gpio_read(struct i2c_client *client, u8 reg)
47 {
48 int ret = i2c_smbus_read_byte_data(client, reg);
49
50 if (ret < 0)
51 dev_err(&client->dev, "Read Error\n");
52
53 return ret;
54 }
55
adp5588_gpio_write(struct i2c_client * client,u8 reg,u8 val)56 static int adp5588_gpio_write(struct i2c_client *client, u8 reg, u8 val)
57 {
58 int ret = i2c_smbus_write_byte_data(client, reg, val);
59
60 if (ret < 0)
61 dev_err(&client->dev, "Write Error\n");
62
63 return ret;
64 }
65
adp5588_gpio_get_value(struct gpio_chip * chip,unsigned off)66 static int adp5588_gpio_get_value(struct gpio_chip *chip, unsigned off)
67 {
68 struct adp5588_gpio *dev =
69 container_of(chip, struct adp5588_gpio, gpio_chip);
70 unsigned bank = ADP5588_BANK(off);
71 unsigned bit = ADP5588_BIT(off);
72 int val;
73
74 mutex_lock(&dev->lock);
75
76 if (dev->dir[bank] & bit)
77 val = dev->dat_out[bank];
78 else
79 val = adp5588_gpio_read(dev->client, GPIO_DAT_STAT1 + bank);
80
81 mutex_unlock(&dev->lock);
82
83 return !!(val & bit);
84 }
85
adp5588_gpio_set_value(struct gpio_chip * chip,unsigned off,int val)86 static void adp5588_gpio_set_value(struct gpio_chip *chip,
87 unsigned off, int val)
88 {
89 unsigned bank, bit;
90 struct adp5588_gpio *dev =
91 container_of(chip, struct adp5588_gpio, gpio_chip);
92
93 bank = ADP5588_BANK(off);
94 bit = ADP5588_BIT(off);
95
96 mutex_lock(&dev->lock);
97 if (val)
98 dev->dat_out[bank] |= bit;
99 else
100 dev->dat_out[bank] &= ~bit;
101
102 adp5588_gpio_write(dev->client, GPIO_DAT_OUT1 + bank,
103 dev->dat_out[bank]);
104 mutex_unlock(&dev->lock);
105 }
106
adp5588_gpio_direction_input(struct gpio_chip * chip,unsigned off)107 static int adp5588_gpio_direction_input(struct gpio_chip *chip, unsigned off)
108 {
109 int ret;
110 unsigned bank;
111 struct adp5588_gpio *dev =
112 container_of(chip, struct adp5588_gpio, gpio_chip);
113
114 bank = ADP5588_BANK(off);
115
116 mutex_lock(&dev->lock);
117 dev->dir[bank] &= ~ADP5588_BIT(off);
118 ret = adp5588_gpio_write(dev->client, GPIO_DIR1 + bank, dev->dir[bank]);
119 mutex_unlock(&dev->lock);
120
121 return ret;
122 }
123
adp5588_gpio_direction_output(struct gpio_chip * chip,unsigned off,int val)124 static int adp5588_gpio_direction_output(struct gpio_chip *chip,
125 unsigned off, int val)
126 {
127 int ret;
128 unsigned bank, bit;
129 struct adp5588_gpio *dev =
130 container_of(chip, struct adp5588_gpio, gpio_chip);
131
132 bank = ADP5588_BANK(off);
133 bit = ADP5588_BIT(off);
134
135 mutex_lock(&dev->lock);
136 dev->dir[bank] |= bit;
137
138 if (val)
139 dev->dat_out[bank] |= bit;
140 else
141 dev->dat_out[bank] &= ~bit;
142
143 ret = adp5588_gpio_write(dev->client, GPIO_DAT_OUT1 + bank,
144 dev->dat_out[bank]);
145 ret |= adp5588_gpio_write(dev->client, GPIO_DIR1 + bank,
146 dev->dir[bank]);
147 mutex_unlock(&dev->lock);
148
149 return ret;
150 }
151
152 #ifdef CONFIG_GPIO_ADP5588_IRQ
adp5588_gpio_to_irq(struct gpio_chip * chip,unsigned off)153 static int adp5588_gpio_to_irq(struct gpio_chip *chip, unsigned off)
154 {
155 struct adp5588_gpio *dev =
156 container_of(chip, struct adp5588_gpio, gpio_chip);
157 return dev->irq_base + off;
158 }
159
adp5588_irq_bus_lock(struct irq_data * d)160 static void adp5588_irq_bus_lock(struct irq_data *d)
161 {
162 struct adp5588_gpio *dev = irq_data_get_irq_chip_data(d);
163
164 mutex_lock(&dev->irq_lock);
165 }
166
167 /*
168 * genirq core code can issue chip->mask/unmask from atomic context.
169 * This doesn't work for slow busses where an access needs to sleep.
170 * bus_sync_unlock() is therefore called outside the atomic context,
171 * syncs the current irq mask state with the slow external controller
172 * and unlocks the bus.
173 */
174
adp5588_irq_bus_sync_unlock(struct irq_data * d)175 static void adp5588_irq_bus_sync_unlock(struct irq_data *d)
176 {
177 struct adp5588_gpio *dev = irq_data_get_irq_chip_data(d);
178 int i;
179
180 for (i = 0; i <= ADP5588_BANK(ADP5588_MAXGPIO); i++)
181 if (dev->int_en[i] ^ dev->irq_mask[i]) {
182 dev->int_en[i] = dev->irq_mask[i];
183 adp5588_gpio_write(dev->client, GPIO_INT_EN1 + i,
184 dev->int_en[i]);
185 }
186
187 mutex_unlock(&dev->irq_lock);
188 }
189
adp5588_irq_mask(struct irq_data * d)190 static void adp5588_irq_mask(struct irq_data *d)
191 {
192 struct adp5588_gpio *dev = irq_data_get_irq_chip_data(d);
193 unsigned gpio = d->irq - dev->irq_base;
194
195 dev->irq_mask[ADP5588_BANK(gpio)] &= ~ADP5588_BIT(gpio);
196 }
197
adp5588_irq_unmask(struct irq_data * d)198 static void adp5588_irq_unmask(struct irq_data *d)
199 {
200 struct adp5588_gpio *dev = irq_data_get_irq_chip_data(d);
201 unsigned gpio = d->irq - dev->irq_base;
202
203 dev->irq_mask[ADP5588_BANK(gpio)] |= ADP5588_BIT(gpio);
204 }
205
adp5588_irq_set_type(struct irq_data * d,unsigned int type)206 static int adp5588_irq_set_type(struct irq_data *d, unsigned int type)
207 {
208 struct adp5588_gpio *dev = irq_data_get_irq_chip_data(d);
209 uint16_t gpio = d->irq - dev->irq_base;
210 unsigned bank, bit;
211
212 if ((type & IRQ_TYPE_EDGE_BOTH)) {
213 dev_err(&dev->client->dev, "irq %d: unsupported type %d\n",
214 d->irq, type);
215 return -EINVAL;
216 }
217
218 bank = ADP5588_BANK(gpio);
219 bit = ADP5588_BIT(gpio);
220
221 if (type & IRQ_TYPE_LEVEL_HIGH)
222 dev->int_lvl[bank] |= bit;
223 else if (type & IRQ_TYPE_LEVEL_LOW)
224 dev->int_lvl[bank] &= ~bit;
225 else
226 return -EINVAL;
227
228 adp5588_gpio_direction_input(&dev->gpio_chip, gpio);
229 adp5588_gpio_write(dev->client, GPIO_INT_LVL1 + bank,
230 dev->int_lvl[bank]);
231
232 return 0;
233 }
234
235 static struct irq_chip adp5588_irq_chip = {
236 .name = "adp5588",
237 .irq_mask = adp5588_irq_mask,
238 .irq_unmask = adp5588_irq_unmask,
239 .irq_bus_lock = adp5588_irq_bus_lock,
240 .irq_bus_sync_unlock = adp5588_irq_bus_sync_unlock,
241 .irq_set_type = adp5588_irq_set_type,
242 };
243
adp5588_gpio_read_intstat(struct i2c_client * client,u8 * buf)244 static int adp5588_gpio_read_intstat(struct i2c_client *client, u8 *buf)
245 {
246 int ret = i2c_smbus_read_i2c_block_data(client, GPIO_INT_STAT1, 3, buf);
247
248 if (ret < 0)
249 dev_err(&client->dev, "Read INT_STAT Error\n");
250
251 return ret;
252 }
253
adp5588_irq_handler(int irq,void * devid)254 static irqreturn_t adp5588_irq_handler(int irq, void *devid)
255 {
256 struct adp5588_gpio *dev = devid;
257 unsigned status, bank, bit, pending;
258 int ret;
259 status = adp5588_gpio_read(dev->client, INT_STAT);
260
261 if (status & ADP5588_GPI_INT) {
262 ret = adp5588_gpio_read_intstat(dev->client, dev->irq_stat);
263 if (ret < 0)
264 memset(dev->irq_stat, 0, ARRAY_SIZE(dev->irq_stat));
265
266 for (bank = 0, bit = 0; bank <= ADP5588_BANK(ADP5588_MAXGPIO);
267 bank++, bit = 0) {
268 pending = dev->irq_stat[bank] & dev->irq_mask[bank];
269
270 while (pending) {
271 if (pending & (1 << bit)) {
272 handle_nested_irq(dev->irq_base +
273 (bank << 3) + bit);
274 pending &= ~(1 << bit);
275
276 }
277 bit++;
278 }
279 }
280 }
281
282 adp5588_gpio_write(dev->client, INT_STAT, status); /* Status is W1C */
283
284 return IRQ_HANDLED;
285 }
286
adp5588_irq_setup(struct adp5588_gpio * dev)287 static int adp5588_irq_setup(struct adp5588_gpio *dev)
288 {
289 struct i2c_client *client = dev->client;
290 struct adp5588_gpio_platform_data *pdata =
291 dev_get_platdata(&client->dev);
292 unsigned gpio;
293 int ret;
294
295 adp5588_gpio_write(client, CFG, ADP5588_AUTO_INC);
296 adp5588_gpio_write(client, INT_STAT, -1); /* status is W1C */
297 adp5588_gpio_read_intstat(client, dev->irq_stat); /* read to clear */
298
299 dev->irq_base = pdata->irq_base;
300 mutex_init(&dev->irq_lock);
301
302 for (gpio = 0; gpio < dev->gpio_chip.ngpio; gpio++) {
303 int irq = gpio + dev->irq_base;
304 irq_set_chip_data(irq, dev);
305 irq_set_chip_and_handler(irq, &adp5588_irq_chip,
306 handle_level_irq);
307 irq_set_nested_thread(irq, 1);
308 #ifdef CONFIG_ARM
309 /*
310 * ARM needs us to explicitly flag the IRQ as VALID,
311 * once we do so, it will also set the noprobe.
312 */
313 set_irq_flags(irq, IRQF_VALID);
314 #else
315 irq_set_noprobe(irq);
316 #endif
317 }
318
319 ret = request_threaded_irq(client->irq,
320 NULL,
321 adp5588_irq_handler,
322 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
323 dev_name(&client->dev), dev);
324 if (ret) {
325 dev_err(&client->dev, "failed to request irq %d\n",
326 client->irq);
327 goto out;
328 }
329
330 dev->gpio_chip.to_irq = adp5588_gpio_to_irq;
331 adp5588_gpio_write(client, CFG,
332 ADP5588_AUTO_INC | ADP5588_INT_CFG | ADP5588_GPI_INT);
333
334 return 0;
335
336 out:
337 dev->irq_base = 0;
338 return ret;
339 }
340
adp5588_irq_teardown(struct adp5588_gpio * dev)341 static void adp5588_irq_teardown(struct adp5588_gpio *dev)
342 {
343 if (dev->irq_base)
344 free_irq(dev->client->irq, dev);
345 }
346
347 #else
adp5588_irq_setup(struct adp5588_gpio * dev)348 static int adp5588_irq_setup(struct adp5588_gpio *dev)
349 {
350 struct i2c_client *client = dev->client;
351 dev_warn(&client->dev, "interrupt support not compiled in\n");
352
353 return 0;
354 }
355
adp5588_irq_teardown(struct adp5588_gpio * dev)356 static void adp5588_irq_teardown(struct adp5588_gpio *dev)
357 {
358 }
359 #endif /* CONFIG_GPIO_ADP5588_IRQ */
360
adp5588_gpio_probe(struct i2c_client * client,const struct i2c_device_id * id)361 static int adp5588_gpio_probe(struct i2c_client *client,
362 const struct i2c_device_id *id)
363 {
364 struct adp5588_gpio_platform_data *pdata =
365 dev_get_platdata(&client->dev);
366 struct adp5588_gpio *dev;
367 struct gpio_chip *gc;
368 int ret, i, revid;
369
370 if (pdata == NULL) {
371 dev_err(&client->dev, "missing platform data\n");
372 return -ENODEV;
373 }
374
375 if (!i2c_check_functionality(client->adapter,
376 I2C_FUNC_SMBUS_BYTE_DATA)) {
377 dev_err(&client->dev, "SMBUS Byte Data not Supported\n");
378 return -EIO;
379 }
380
381 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
382 if (dev == NULL)
383 return -ENOMEM;
384
385 dev->client = client;
386
387 gc = &dev->gpio_chip;
388 gc->direction_input = adp5588_gpio_direction_input;
389 gc->direction_output = adp5588_gpio_direction_output;
390 gc->get = adp5588_gpio_get_value;
391 gc->set = adp5588_gpio_set_value;
392 gc->can_sleep = true;
393
394 gc->base = pdata->gpio_start;
395 gc->ngpio = ADP5588_MAXGPIO;
396 gc->label = client->name;
397 gc->owner = THIS_MODULE;
398 gc->names = pdata->names;
399
400 mutex_init(&dev->lock);
401
402 ret = adp5588_gpio_read(dev->client, DEV_ID);
403 if (ret < 0)
404 goto err;
405
406 revid = ret & ADP5588_DEVICE_ID_MASK;
407
408 for (i = 0, ret = 0; i <= ADP5588_BANK(ADP5588_MAXGPIO); i++) {
409 dev->dat_out[i] = adp5588_gpio_read(client, GPIO_DAT_OUT1 + i);
410 dev->dir[i] = adp5588_gpio_read(client, GPIO_DIR1 + i);
411 ret |= adp5588_gpio_write(client, KP_GPIO1 + i, 0);
412 ret |= adp5588_gpio_write(client, GPIO_PULL1 + i,
413 (pdata->pullup_dis_mask >> (8 * i)) & 0xFF);
414 ret |= adp5588_gpio_write(client, GPIO_INT_EN1 + i, 0);
415 if (ret)
416 goto err;
417 }
418
419 if (pdata->irq_base) {
420 if (WA_DELAYED_READOUT_REVID(revid)) {
421 dev_warn(&client->dev, "GPIO int not supported\n");
422 } else {
423 ret = adp5588_irq_setup(dev);
424 if (ret)
425 goto err;
426 }
427 }
428
429 ret = gpiochip_add(&dev->gpio_chip);
430 if (ret)
431 goto err_irq;
432
433 dev_info(&client->dev, "IRQ Base: %d Rev.: %d\n",
434 pdata->irq_base, revid);
435
436 if (pdata->setup) {
437 ret = pdata->setup(client, gc->base, gc->ngpio, pdata->context);
438 if (ret < 0)
439 dev_warn(&client->dev, "setup failed, %d\n", ret);
440 }
441
442 i2c_set_clientdata(client, dev);
443
444 return 0;
445
446 err_irq:
447 adp5588_irq_teardown(dev);
448 err:
449 kfree(dev);
450 return ret;
451 }
452
adp5588_gpio_remove(struct i2c_client * client)453 static int adp5588_gpio_remove(struct i2c_client *client)
454 {
455 struct adp5588_gpio_platform_data *pdata =
456 dev_get_platdata(&client->dev);
457 struct adp5588_gpio *dev = i2c_get_clientdata(client);
458 int ret;
459
460 if (pdata->teardown) {
461 ret = pdata->teardown(client,
462 dev->gpio_chip.base, dev->gpio_chip.ngpio,
463 pdata->context);
464 if (ret < 0) {
465 dev_err(&client->dev, "teardown failed %d\n", ret);
466 return ret;
467 }
468 }
469
470 if (dev->irq_base)
471 free_irq(dev->client->irq, dev);
472
473 gpiochip_remove(&dev->gpio_chip);
474
475 kfree(dev);
476 return 0;
477 }
478
479 static const struct i2c_device_id adp5588_gpio_id[] = {
480 {DRV_NAME, 0},
481 {}
482 };
483
484 MODULE_DEVICE_TABLE(i2c, adp5588_gpio_id);
485
486 static struct i2c_driver adp5588_gpio_driver = {
487 .driver = {
488 .name = DRV_NAME,
489 },
490 .probe = adp5588_gpio_probe,
491 .remove = adp5588_gpio_remove,
492 .id_table = adp5588_gpio_id,
493 };
494
495 module_i2c_driver(adp5588_gpio_driver);
496
497 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
498 MODULE_DESCRIPTION("GPIO ADP5588 Driver");
499 MODULE_LICENSE("GPL");
500