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
30struct 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
46static 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
56static 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
66static 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
86static 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
107static 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
124static 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
153static 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
160static 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
175static 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
190static 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
198static 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
206static 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
235static 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
244static 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
254static 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
287static 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
336out:
337	dev->irq_base = 0;
338	return ret;
339}
340
341static 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
348static 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
356static void adp5588_irq_teardown(struct adp5588_gpio *dev)
357{
358}
359#endif /* CONFIG_GPIO_ADP5588_IRQ */
360
361static 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) {
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 = devm_kzalloc(&client->dev, sizeof(*dev), GFP_KERNEL);
382	if (!dev)
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
446err_irq:
447	adp5588_irq_teardown(dev);
448err:
449	return ret;
450}
451
452static int adp5588_gpio_remove(struct i2c_client *client)
453{
454	struct adp5588_gpio_platform_data *pdata =
455			dev_get_platdata(&client->dev);
456	struct adp5588_gpio *dev = i2c_get_clientdata(client);
457	int ret;
458
459	if (pdata->teardown) {
460		ret = pdata->teardown(client,
461				      dev->gpio_chip.base, dev->gpio_chip.ngpio,
462				      pdata->context);
463		if (ret < 0) {
464			dev_err(&client->dev, "teardown failed %d\n", ret);
465			return ret;
466		}
467	}
468
469	if (dev->irq_base)
470		free_irq(dev->client->irq, dev);
471
472	gpiochip_remove(&dev->gpio_chip);
473
474	return 0;
475}
476
477static const struct i2c_device_id adp5588_gpio_id[] = {
478	{DRV_NAME, 0},
479	{}
480};
481
482MODULE_DEVICE_TABLE(i2c, adp5588_gpio_id);
483
484static struct i2c_driver adp5588_gpio_driver = {
485	.driver = {
486		   .name = DRV_NAME,
487		   },
488	.probe = adp5588_gpio_probe,
489	.remove = adp5588_gpio_remove,
490	.id_table = adp5588_gpio_id,
491};
492
493module_i2c_driver(adp5588_gpio_driver);
494
495MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
496MODULE_DESCRIPTION("GPIO ADP5588 Driver");
497MODULE_LICENSE("GPL");
498