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