1/*
2 * Copyright (C) ST-Ericsson SA 2011
3 *
4 * Author: BIBEK BASU <bibek.basu@stericsson.com>
5 * License terms: GNU General Public License (GPL) version 2
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11#include <linux/kernel.h>
12#include <linux/types.h>
13#include <linux/slab.h>
14#include <linux/init.h>
15#include <linux/module.h>
16#include <linux/err.h>
17#include <linux/platform_device.h>
18#include <linux/gpio.h>
19#include <linux/irq.h>
20#include <linux/interrupt.h>
21#include <linux/mfd/ab8500.h>
22#include <linux/mfd/abx500.h>
23#include <linux/mfd/ab8500/gpio.h>
24
25/*
26 * GPIO registers offset
27 * Bank: 0x10
28 */
29#define AB8500_GPIO_SEL1_REG	0x00
30#define AB8500_GPIO_SEL2_REG	0x01
31#define AB8500_GPIO_SEL3_REG	0x02
32#define AB8500_GPIO_SEL4_REG	0x03
33#define AB8500_GPIO_SEL5_REG	0x04
34#define AB8500_GPIO_SEL6_REG	0x05
35
36#define AB8500_GPIO_DIR1_REG	0x10
37#define AB8500_GPIO_DIR2_REG	0x11
38#define AB8500_GPIO_DIR3_REG	0x12
39#define AB8500_GPIO_DIR4_REG	0x13
40#define AB8500_GPIO_DIR5_REG	0x14
41#define AB8500_GPIO_DIR6_REG	0x15
42
43#define AB8500_GPIO_OUT1_REG	0x20
44#define AB8500_GPIO_OUT2_REG	0x21
45#define AB8500_GPIO_OUT3_REG	0x22
46#define AB8500_GPIO_OUT4_REG	0x23
47#define AB8500_GPIO_OUT5_REG	0x24
48#define AB8500_GPIO_OUT6_REG	0x25
49
50#define AB8500_GPIO_PUD1_REG	0x30
51#define AB8500_GPIO_PUD2_REG	0x31
52#define AB8500_GPIO_PUD3_REG	0x32
53#define AB8500_GPIO_PUD4_REG	0x33
54#define AB8500_GPIO_PUD5_REG	0x34
55#define AB8500_GPIO_PUD6_REG	0x35
56
57#define AB8500_GPIO_IN1_REG	0x40
58#define AB8500_GPIO_IN2_REG	0x41
59#define AB8500_GPIO_IN3_REG	0x42
60#define AB8500_GPIO_IN4_REG	0x43
61#define AB8500_GPIO_IN5_REG	0x44
62#define AB8500_GPIO_IN6_REG	0x45
63#define AB8500_GPIO_ALTFUN_REG	0x45
64#define ALTFUN_REG_INDEX	6
65#define AB8500_NUM_GPIO		42
66#define AB8500_NUM_VIR_GPIO_IRQ	16
67
68enum ab8500_gpio_action {
69	NONE,
70	STARTUP,
71	SHUTDOWN,
72	MASK,
73	UNMASK
74};
75
76struct ab8500_gpio {
77	struct gpio_chip chip;
78	struct ab8500 *parent;
79	struct device *dev;
80	struct mutex lock;
81	u32 irq_base;
82	enum ab8500_gpio_action irq_action;
83	u16 rising;
84	u16 falling;
85};
86/**
87 * to_ab8500_gpio() - get the pointer to ab8500_gpio
88 * @chip:	Member of the structure ab8500_gpio
89 */
90static inline struct ab8500_gpio *to_ab8500_gpio(struct gpio_chip *chip)
91{
92	return container_of(chip, struct ab8500_gpio, chip);
93}
94
95static int ab8500_gpio_set_bits(struct gpio_chip *chip, u8 reg,
96					unsigned offset, int val)
97{
98	struct ab8500_gpio *ab8500_gpio = to_ab8500_gpio(chip);
99	u8 pos = offset % 8;
100	int ret;
101
102	reg = reg + (offset / 8);
103	ret = abx500_mask_and_set_register_interruptible(ab8500_gpio->dev,
104				AB8500_MISC, reg, 1 << pos, val << pos);
105	if (ret < 0)
106		dev_err(ab8500_gpio->dev, "%s write failed\n", __func__);
107	return ret;
108}
109/**
110 * ab8500_gpio_get() - Get the particular GPIO value
111 * @chip: Gpio device
112 * @offset: GPIO number to read
113 */
114static int ab8500_gpio_get(struct gpio_chip *chip, unsigned offset)
115{
116	struct ab8500_gpio *ab8500_gpio = to_ab8500_gpio(chip);
117	u8 mask = 1 << (offset % 8);
118	u8 reg = AB8500_GPIO_OUT1_REG + (offset / 8);
119	int ret;
120	u8 data;
121	ret = abx500_get_register_interruptible(ab8500_gpio->dev, AB8500_MISC,
122						reg, &data);
123	if (ret < 0) {
124		dev_err(ab8500_gpio->dev, "%s read failed\n", __func__);
125		return ret;
126	}
127	return (data & mask) >> (offset % 8);
128}
129
130static void ab8500_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
131{
132	struct ab8500_gpio *ab8500_gpio = to_ab8500_gpio(chip);
133	int ret;
134	/* Write the data */
135	ret = ab8500_gpio_set_bits(chip, AB8500_GPIO_OUT1_REG, offset, 1);
136	if (ret < 0)
137		dev_err(ab8500_gpio->dev, "%s write failed\n", __func__);
138}
139
140static int ab8500_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
141					int val)
142{
143	int ret;
144	/* set direction as output */
145	ret = ab8500_gpio_set_bits(chip, AB8500_GPIO_DIR1_REG, offset, 1);
146	if (ret < 0)
147		return ret;
148	/* disable pull down */
149	ret = ab8500_gpio_set_bits(chip, AB8500_GPIO_PUD1_REG, offset, 1);
150	if (ret < 0)
151		return ret;
152	/* set the output as 1 or 0 */
153	return ab8500_gpio_set_bits(chip, AB8500_GPIO_OUT1_REG, offset, val);
154
155}
156
157static int ab8500_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
158{
159	/* set the register as input */
160	return ab8500_gpio_set_bits(chip, AB8500_GPIO_DIR1_REG, offset, 0);
161}
162
163static int ab8500_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
164{
165	/*
166	 * Only some GPIOs are interrupt capable, and they are
167	 * organized in discontiguous clusters:
168	 *
169	 *	GPIO6 to GPIO13
170	 *	GPIO24 and GPIO25
171	 *	GPIO36 to GPIO41
172	 */
173	static struct ab8500_gpio_irq_cluster {
174		int start;
175		int end;
176	} clusters[] = {
177		{.start = 6,  .end = 13},
178		{.start = 24, .end = 25},
179		{.start = 36, .end = 41},
180	};
181	struct ab8500_gpio *ab8500_gpio = to_ab8500_gpio(chip);
182	int base = ab8500_gpio->irq_base;
183	int i;
184
185	for (i = 0; i < ARRAY_SIZE(clusters); i++) {
186		struct ab8500_gpio_irq_cluster *cluster = &clusters[i];
187
188		if (offset >= cluster->start && offset <= cluster->end)
189			return base + offset - cluster->start;
190
191		/* Advance by the number of gpios in this cluster */
192		base += cluster->end - cluster->start + 1;
193	}
194
195	return -EINVAL;
196}
197
198static struct gpio_chip ab8500gpio_chip = {
199	.label			= "ab8500_gpio",
200	.owner			= THIS_MODULE,
201	.direction_input	= ab8500_gpio_direction_input,
202	.get			= ab8500_gpio_get,
203	.direction_output	= ab8500_gpio_direction_output,
204	.set			= ab8500_gpio_set,
205	.to_irq			= ab8500_gpio_to_irq,
206};
207
208static unsigned int irq_to_rising(unsigned int irq)
209{
210	struct ab8500_gpio *ab8500_gpio = get_irq_chip_data(irq);
211	int offset = irq - ab8500_gpio->irq_base;
212	int new_irq = offset +  AB8500_INT_GPIO6R
213			+ ab8500_gpio->parent->irq_base;
214	return new_irq;
215}
216
217static unsigned int irq_to_falling(unsigned int irq)
218{
219	struct ab8500_gpio *ab8500_gpio = get_irq_chip_data(irq);
220	int offset = irq - ab8500_gpio->irq_base;
221	int new_irq = offset +  AB8500_INT_GPIO6F
222			+  ab8500_gpio->parent->irq_base;
223	return new_irq;
224
225}
226
227static unsigned int rising_to_irq(unsigned int irq, void *dev)
228{
229	struct ab8500_gpio *ab8500_gpio = dev;
230	int offset = irq - AB8500_INT_GPIO6R
231			- ab8500_gpio->parent->irq_base ;
232	int new_irq = offset + ab8500_gpio->irq_base;
233	return new_irq;
234}
235
236static unsigned int falling_to_irq(unsigned int irq, void *dev)
237{
238	struct ab8500_gpio *ab8500_gpio = dev;
239	int offset = irq - AB8500_INT_GPIO6F
240			- ab8500_gpio->parent->irq_base ;
241	int new_irq = offset + ab8500_gpio->irq_base;
242	return new_irq;
243
244}
245
246/*
247 * IRQ handler
248 */
249
250static irqreturn_t handle_rising(int irq, void *dev)
251{
252
253	handle_nested_irq(rising_to_irq(irq , dev));
254	return IRQ_HANDLED;
255}
256
257static irqreturn_t handle_falling(int irq, void *dev)
258{
259
260	handle_nested_irq(falling_to_irq(irq, dev));
261	return IRQ_HANDLED;
262}
263
264static void ab8500_gpio_irq_lock(unsigned int irq)
265{
266	struct ab8500_gpio *ab8500_gpio = get_irq_chip_data(irq);
267	mutex_lock(&ab8500_gpio->lock);
268}
269
270static void ab8500_gpio_irq_sync_unlock(unsigned int irq)
271{
272	struct ab8500_gpio *ab8500_gpio = get_irq_chip_data(irq);
273	int offset = irq - ab8500_gpio->irq_base;
274	bool rising = ab8500_gpio->rising & BIT(offset);
275	bool falling = ab8500_gpio->falling & BIT(offset);
276	int ret;
277
278	switch (ab8500_gpio->irq_action)	{
279	case STARTUP:
280		if (rising)
281			ret = request_threaded_irq(irq_to_rising(irq),
282					NULL, handle_rising,
283					IRQF_TRIGGER_RISING,
284					"ab8500-gpio-r", ab8500_gpio);
285		if (falling)
286			ret = request_threaded_irq(irq_to_falling(irq),
287				       NULL, handle_falling,
288				       IRQF_TRIGGER_FALLING,
289				       "ab8500-gpio-f", ab8500_gpio);
290		break;
291	case SHUTDOWN:
292		if (rising)
293			free_irq(irq_to_rising(irq), ab8500_gpio);
294		if (falling)
295			free_irq(irq_to_falling(irq), ab8500_gpio);
296		break;
297	case MASK:
298		if (rising)
299			disable_irq(irq_to_rising(irq));
300		if (falling)
301			disable_irq(irq_to_falling(irq));
302		break;
303	case UNMASK:
304		if (rising)
305			enable_irq(irq_to_rising(irq));
306		if (falling)
307			enable_irq(irq_to_falling(irq));
308		break;
309	case NONE:
310		break;
311	}
312	ab8500_gpio->irq_action = NONE;
313	ab8500_gpio->rising &= ~(BIT(offset));
314	ab8500_gpio->falling &= ~(BIT(offset));
315	mutex_unlock(&ab8500_gpio->lock);
316}
317
318
319static void ab8500_gpio_irq_mask(unsigned int irq)
320{
321	struct ab8500_gpio *ab8500_gpio = get_irq_chip_data(irq);
322	ab8500_gpio->irq_action = MASK;
323}
324
325static void ab8500_gpio_irq_unmask(unsigned int irq)
326{
327	struct ab8500_gpio *ab8500_gpio = get_irq_chip_data(irq);
328	ab8500_gpio->irq_action = UNMASK;
329}
330
331static int ab8500_gpio_irq_set_type(unsigned int irq, unsigned int type)
332{
333	struct ab8500_gpio *ab8500_gpio = get_irq_chip_data(irq);
334	int offset = irq - ab8500_gpio->irq_base;
335
336	if (type == IRQ_TYPE_EDGE_BOTH) {
337		ab8500_gpio->rising =  BIT(offset);
338		ab8500_gpio->falling = BIT(offset);
339	} else if (type == IRQ_TYPE_EDGE_RISING) {
340		ab8500_gpio->rising =  BIT(offset);
341	} else  {
342		ab8500_gpio->falling = BIT(offset);
343	}
344	return 0;
345}
346
347unsigned int ab8500_gpio_irq_startup(unsigned int irq)
348{
349	struct ab8500_gpio *ab8500_gpio = get_irq_chip_data(irq);
350	ab8500_gpio->irq_action = STARTUP;
351	return 0;
352}
353
354void ab8500_gpio_irq_shutdown(unsigned int irq)
355{
356	struct ab8500_gpio *ab8500_gpio = get_irq_chip_data(irq);
357	ab8500_gpio->irq_action = SHUTDOWN;
358}
359
360static struct irq_chip ab8500_gpio_irq_chip = {
361	.name			= "ab8500-gpio",
362	.startup		= ab8500_gpio_irq_startup,
363	.shutdown		= ab8500_gpio_irq_shutdown,
364	.bus_lock		= ab8500_gpio_irq_lock,
365	.bus_sync_unlock	= ab8500_gpio_irq_sync_unlock,
366	.mask			= ab8500_gpio_irq_mask,
367	.unmask			= ab8500_gpio_irq_unmask,
368	.set_type		= ab8500_gpio_irq_set_type,
369};
370
371static int ab8500_gpio_irq_init(struct ab8500_gpio *ab8500_gpio)
372{
373	u32 base = ab8500_gpio->irq_base;
374	int irq;
375
376	for (irq = base; irq < base + AB8500_NUM_VIR_GPIO_IRQ ; irq++) {
377		set_irq_chip_data(irq, ab8500_gpio);
378		set_irq_chip_and_handler(irq, &ab8500_gpio_irq_chip,
379				handle_simple_irq);
380		set_irq_nested_thread(irq, 1);
381#ifdef CONFIG_ARM
382		set_irq_flags(irq, IRQF_VALID);
383#else
384		set_irq_noprobe(irq);
385#endif
386	}
387
388	return 0;
389}
390
391static void ab8500_gpio_irq_remove(struct ab8500_gpio *ab8500_gpio)
392{
393	int base = ab8500_gpio->irq_base;
394	int irq;
395
396	for (irq = base; irq < base + AB8500_NUM_VIR_GPIO_IRQ; irq++) {
397#ifdef CONFIG_ARM
398		set_irq_flags(irq, 0);
399#endif
400		set_irq_chip_and_handler(irq, NULL, NULL);
401		set_irq_chip_data(irq, NULL);
402	}
403}
404
405static int __devinit ab8500_gpio_probe(struct platform_device *pdev)
406{
407	struct ab8500_platform_data *ab8500_pdata =
408				dev_get_platdata(pdev->dev.parent);
409	struct ab8500_gpio_platform_data *pdata;
410	struct ab8500_gpio *ab8500_gpio;
411	int ret;
412	int i;
413
414	pdata = ab8500_pdata->gpio;
415	if (!pdata)	{
416		dev_err(&pdev->dev, "gpio platform data missing\n");
417		return -ENODEV;
418	}
419
420	ab8500_gpio = kzalloc(sizeof(struct ab8500_gpio), GFP_KERNEL);
421	if (ab8500_gpio == NULL) {
422		dev_err(&pdev->dev, "failed to allocate memory\n");
423		return -ENOMEM;
424	}
425	ab8500_gpio->dev = &pdev->dev;
426	ab8500_gpio->parent = dev_get_drvdata(pdev->dev.parent);
427	ab8500_gpio->chip = ab8500gpio_chip;
428	ab8500_gpio->chip.ngpio = AB8500_NUM_GPIO;
429	ab8500_gpio->chip.dev = &pdev->dev;
430	ab8500_gpio->chip.base = pdata->gpio_base;
431	ab8500_gpio->irq_base = pdata->irq_base;
432	/* initialize the lock */
433	mutex_init(&ab8500_gpio->lock);
434	/*
435	 * AB8500 core will handle and clear the IRQ
436	 * configre GPIO based on config-reg value.
437	 * These values are for selecting the PINs as
438	 * GPIO or alternate function
439	 */
440	for (i = AB8500_GPIO_SEL1_REG; i <= AB8500_GPIO_SEL6_REG; i++)	{
441		ret = abx500_set_register_interruptible(ab8500_gpio->dev,
442				AB8500_MISC, i,
443				pdata->config_reg[i]);
444		if (ret < 0)
445			goto out_free;
446	}
447	ret = abx500_set_register_interruptible(ab8500_gpio->dev, AB8500_MISC,
448				AB8500_GPIO_ALTFUN_REG,
449				pdata->config_reg[ALTFUN_REG_INDEX]);
450	if (ret < 0)
451		goto out_free;
452
453	ret = ab8500_gpio_irq_init(ab8500_gpio);
454	if (ret)
455		goto out_free;
456	ret = gpiochip_add(&ab8500_gpio->chip);
457	if (ret) {
458		dev_err(&pdev->dev, "unable to add gpiochip: %d\n",
459				ret);
460		goto out_rem_irq;
461	}
462	platform_set_drvdata(pdev, ab8500_gpio);
463	return 0;
464
465out_rem_irq:
466	ab8500_gpio_irq_remove(ab8500_gpio);
467out_free:
468	mutex_destroy(&ab8500_gpio->lock);
469	kfree(ab8500_gpio);
470	return ret;
471}
472
473/*
474 * ab8500_gpio_remove() - remove Ab8500-gpio driver
475 * @pdev :	Platform device registered
476 */
477static int __devexit ab8500_gpio_remove(struct platform_device *pdev)
478{
479	struct ab8500_gpio *ab8500_gpio = platform_get_drvdata(pdev);
480	int ret;
481
482	ret = gpiochip_remove(&ab8500_gpio->chip);
483	if (ret < 0) {
484		dev_err(ab8500_gpio->dev, "unable to remove gpiochip: %d\n",
485			ret);
486		return ret;
487	}
488
489	platform_set_drvdata(pdev, NULL);
490	mutex_destroy(&ab8500_gpio->lock);
491	kfree(ab8500_gpio);
492
493	return 0;
494}
495
496static struct platform_driver ab8500_gpio_driver = {
497	.driver = {
498		.name = "ab8500-gpio",
499		.owner = THIS_MODULE,
500	},
501	.probe = ab8500_gpio_probe,
502	.remove = __devexit_p(ab8500_gpio_remove),
503};
504
505static int __init ab8500_gpio_init(void)
506{
507	return platform_driver_register(&ab8500_gpio_driver);
508}
509arch_initcall(ab8500_gpio_init);
510
511static void __exit ab8500_gpio_exit(void)
512{
513	platform_driver_unregister(&ab8500_gpio_driver);
514}
515module_exit(ab8500_gpio_exit);
516
517MODULE_AUTHOR("BIBEK BASU <bibek.basu@stericsson.com>");
518MODULE_DESCRIPTION("Driver allows to use AB8500 unused pins to be used as GPIO");
519MODULE_ALIAS("platform:ab8500-gpio");
520MODULE_LICENSE("GPL v2");
521