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  • only in /netgear-R7000-V1.0.7.12_1.2.5/components/opensource/linux/linux-2.6.36/arch/arm/plat-pxa/
1/*
2 *  linux/arch/arm/plat-pxa/gpio.c
3 *
4 *  Generic PXA GPIO handling
5 *
6 *  Author:	Nicolas Pitre
7 *  Created:	Jun 15, 2001
8 *  Copyright:	MontaVista Software Inc.
9 *
10 *  This program is free software; you can redistribute it and/or modify
11 *  it under the terms of the GNU General Public License version 2 as
12 *  published by the Free Software Foundation.
13 */
14
15#include <linux/init.h>
16#include <linux/irq.h>
17#include <linux/io.h>
18#include <linux/sysdev.h>
19#include <linux/slab.h>
20
21#include <mach/gpio.h>
22
23int pxa_last_gpio;
24
25struct pxa_gpio_chip {
26	struct gpio_chip chip;
27	void __iomem	*regbase;
28	char label[10];
29
30	unsigned long	irq_mask;
31	unsigned long	irq_edge_rise;
32	unsigned long	irq_edge_fall;
33
34#ifdef CONFIG_PM
35	unsigned long	saved_gplr;
36	unsigned long	saved_gpdr;
37	unsigned long	saved_grer;
38	unsigned long	saved_gfer;
39#endif
40};
41
42static DEFINE_SPINLOCK(gpio_lock);
43static struct pxa_gpio_chip *pxa_gpio_chips;
44
45#define for_each_gpio_chip(i, c)			\
46	for (i = 0, c = &pxa_gpio_chips[0]; i <= pxa_last_gpio; i += 32, c++)
47
48static inline void __iomem *gpio_chip_base(struct gpio_chip *c)
49{
50	return container_of(c, struct pxa_gpio_chip, chip)->regbase;
51}
52
53static inline struct pxa_gpio_chip *gpio_to_chip(unsigned gpio)
54{
55	return &pxa_gpio_chips[gpio_to_bank(gpio)];
56}
57
58static int pxa_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
59{
60	void __iomem *base = gpio_chip_base(chip);
61	uint32_t value, mask = 1 << offset;
62	unsigned long flags;
63
64	spin_lock_irqsave(&gpio_lock, flags);
65
66	value = __raw_readl(base + GPDR_OFFSET);
67	if (__gpio_is_inverted(chip->base + offset))
68		value |= mask;
69	else
70		value &= ~mask;
71	__raw_writel(value, base + GPDR_OFFSET);
72
73	spin_unlock_irqrestore(&gpio_lock, flags);
74	return 0;
75}
76
77static int pxa_gpio_direction_output(struct gpio_chip *chip,
78				     unsigned offset, int value)
79{
80	void __iomem *base = gpio_chip_base(chip);
81	uint32_t tmp, mask = 1 << offset;
82	unsigned long flags;
83
84	__raw_writel(mask, base + (value ? GPSR_OFFSET : GPCR_OFFSET));
85
86	spin_lock_irqsave(&gpio_lock, flags);
87
88	tmp = __raw_readl(base + GPDR_OFFSET);
89	if (__gpio_is_inverted(chip->base + offset))
90		tmp &= ~mask;
91	else
92		tmp |= mask;
93	__raw_writel(tmp, base + GPDR_OFFSET);
94
95	spin_unlock_irqrestore(&gpio_lock, flags);
96	return 0;
97}
98
99static int pxa_gpio_get(struct gpio_chip *chip, unsigned offset)
100{
101	return __raw_readl(gpio_chip_base(chip) + GPLR_OFFSET) & (1 << offset);
102}
103
104static void pxa_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
105{
106	__raw_writel(1 << offset, gpio_chip_base(chip) +
107				(value ? GPSR_OFFSET : GPCR_OFFSET));
108}
109
110static int __init pxa_init_gpio_chip(int gpio_end)
111{
112	int i, gpio, nbanks = gpio_to_bank(gpio_end) + 1;
113	struct pxa_gpio_chip *chips;
114
115	chips = kzalloc(nbanks * sizeof(struct pxa_gpio_chip), GFP_KERNEL);
116	if (chips == NULL) {
117		pr_err("%s: failed to allocate GPIO chips\n", __func__);
118		return -ENOMEM;
119	}
120
121	for (i = 0, gpio = 0; i < nbanks; i++, gpio += 32) {
122		struct gpio_chip *c = &chips[i].chip;
123
124		sprintf(chips[i].label, "gpio-%d", i);
125		chips[i].regbase = (void __iomem *)GPIO_BANK(i);
126
127		c->base  = gpio;
128		c->label = chips[i].label;
129
130		c->direction_input  = pxa_gpio_direction_input;
131		c->direction_output = pxa_gpio_direction_output;
132		c->get = pxa_gpio_get;
133		c->set = pxa_gpio_set;
134
135		/* number of GPIOs on last bank may be less than 32 */
136		c->ngpio = (gpio + 31 > gpio_end) ? (gpio_end - gpio + 1) : 32;
137		gpiochip_add(c);
138	}
139	pxa_gpio_chips = chips;
140	return 0;
141}
142
143/* Update only those GRERx and GFERx edge detection register bits if those
144 * bits are set in c->irq_mask
145 */
146static inline void update_edge_detect(struct pxa_gpio_chip *c)
147{
148	uint32_t grer, gfer;
149
150	grer = __raw_readl(c->regbase + GRER_OFFSET) & ~c->irq_mask;
151	gfer = __raw_readl(c->regbase + GFER_OFFSET) & ~c->irq_mask;
152	grer |= c->irq_edge_rise & c->irq_mask;
153	gfer |= c->irq_edge_fall & c->irq_mask;
154	__raw_writel(grer, c->regbase + GRER_OFFSET);
155	__raw_writel(gfer, c->regbase + GFER_OFFSET);
156}
157
158static int pxa_gpio_irq_type(unsigned int irq, unsigned int type)
159{
160	struct pxa_gpio_chip *c;
161	int gpio = irq_to_gpio(irq);
162	unsigned long gpdr, mask = GPIO_bit(gpio);
163
164	c = gpio_to_chip(gpio);
165
166	if (type == IRQ_TYPE_PROBE) {
167		/* Don't mess with enabled GPIOs using preconfigured edges or
168		 * GPIOs set to alternate function or to output during probe
169		 */
170		if ((c->irq_edge_rise | c->irq_edge_fall) & GPIO_bit(gpio))
171			return 0;
172
173		if (__gpio_is_occupied(gpio))
174			return 0;
175
176		type = IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING;
177	}
178
179	gpdr = __raw_readl(c->regbase + GPDR_OFFSET);
180
181	if (__gpio_is_inverted(gpio))
182		__raw_writel(gpdr | mask,  c->regbase + GPDR_OFFSET);
183	else
184		__raw_writel(gpdr & ~mask, c->regbase + GPDR_OFFSET);
185
186	if (type & IRQ_TYPE_EDGE_RISING)
187		c->irq_edge_rise |= mask;
188	else
189		c->irq_edge_rise &= ~mask;
190
191	if (type & IRQ_TYPE_EDGE_FALLING)
192		c->irq_edge_fall |= mask;
193	else
194		c->irq_edge_fall &= ~mask;
195
196	update_edge_detect(c);
197
198	pr_debug("%s: IRQ%d (GPIO%d) - edge%s%s\n", __func__, irq, gpio,
199		((type & IRQ_TYPE_EDGE_RISING)  ? " rising"  : ""),
200		((type & IRQ_TYPE_EDGE_FALLING) ? " falling" : ""));
201	return 0;
202}
203
204static void pxa_gpio_demux_handler(unsigned int irq, struct irq_desc *desc)
205{
206	struct pxa_gpio_chip *c;
207	int loop, gpio, gpio_base, n;
208	unsigned long gedr;
209
210	do {
211		loop = 0;
212		for_each_gpio_chip(gpio, c) {
213			gpio_base = c->chip.base;
214
215			gedr = __raw_readl(c->regbase + GEDR_OFFSET);
216			gedr = gedr & c->irq_mask;
217			__raw_writel(gedr, c->regbase + GEDR_OFFSET);
218
219			n = find_first_bit(&gedr, BITS_PER_LONG);
220			while (n < BITS_PER_LONG) {
221				loop = 1;
222
223				generic_handle_irq(gpio_to_irq(gpio_base + n));
224				n = find_next_bit(&gedr, BITS_PER_LONG, n + 1);
225			}
226		}
227	} while (loop);
228}
229
230static void pxa_ack_muxed_gpio(unsigned int irq)
231{
232	int gpio = irq_to_gpio(irq);
233	struct pxa_gpio_chip *c = gpio_to_chip(gpio);
234
235	__raw_writel(GPIO_bit(gpio), c->regbase + GEDR_OFFSET);
236}
237
238static void pxa_mask_muxed_gpio(unsigned int irq)
239{
240	int gpio = irq_to_gpio(irq);
241	struct pxa_gpio_chip *c = gpio_to_chip(gpio);
242	uint32_t grer, gfer;
243
244	c->irq_mask &= ~GPIO_bit(gpio);
245
246	grer = __raw_readl(c->regbase + GRER_OFFSET) & ~GPIO_bit(gpio);
247	gfer = __raw_readl(c->regbase + GFER_OFFSET) & ~GPIO_bit(gpio);
248	__raw_writel(grer, c->regbase + GRER_OFFSET);
249	__raw_writel(gfer, c->regbase + GFER_OFFSET);
250}
251
252static void pxa_unmask_muxed_gpio(unsigned int irq)
253{
254	int gpio = irq_to_gpio(irq);
255	struct pxa_gpio_chip *c = gpio_to_chip(gpio);
256
257	c->irq_mask |= GPIO_bit(gpio);
258	update_edge_detect(c);
259}
260
261static struct irq_chip pxa_muxed_gpio_chip = {
262	.name		= "GPIO",
263	.ack		= pxa_ack_muxed_gpio,
264	.mask		= pxa_mask_muxed_gpio,
265	.unmask		= pxa_unmask_muxed_gpio,
266	.set_type	= pxa_gpio_irq_type,
267};
268
269void __init pxa_init_gpio(int mux_irq, int start, int end, set_wake_t fn)
270{
271	struct pxa_gpio_chip *c;
272	int gpio, irq;
273
274	pxa_last_gpio = end;
275
276	/* Initialize GPIO chips */
277	pxa_init_gpio_chip(end);
278
279	/* clear all GPIO edge detects */
280	for_each_gpio_chip(gpio, c) {
281		__raw_writel(0, c->regbase + GFER_OFFSET);
282		__raw_writel(0, c->regbase + GRER_OFFSET);
283		__raw_writel(~0,c->regbase + GEDR_OFFSET);
284	}
285
286	for (irq  = gpio_to_irq(start); irq <= gpio_to_irq(end); irq++) {
287		set_irq_chip(irq, &pxa_muxed_gpio_chip);
288		set_irq_handler(irq, handle_edge_irq);
289		set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
290	}
291
292	/* Install handler for GPIO>=2 edge detect interrupts */
293	set_irq_chained_handler(mux_irq, pxa_gpio_demux_handler);
294	pxa_muxed_gpio_chip.set_wake = fn;
295}
296
297#ifdef CONFIG_PM
298static int pxa_gpio_suspend(struct sys_device *dev, pm_message_t state)
299{
300	struct pxa_gpio_chip *c;
301	int gpio;
302
303	for_each_gpio_chip(gpio, c) {
304		c->saved_gplr = __raw_readl(c->regbase + GPLR_OFFSET);
305		c->saved_gpdr = __raw_readl(c->regbase + GPDR_OFFSET);
306		c->saved_grer = __raw_readl(c->regbase + GRER_OFFSET);
307		c->saved_gfer = __raw_readl(c->regbase + GFER_OFFSET);
308
309		/* Clear GPIO transition detect bits */
310		__raw_writel(0xffffffff, c->regbase + GEDR_OFFSET);
311	}
312	return 0;
313}
314
315static int pxa_gpio_resume(struct sys_device *dev)
316{
317	struct pxa_gpio_chip *c;
318	int gpio;
319
320	for_each_gpio_chip(gpio, c) {
321		/* restore level with set/clear */
322		__raw_writel( c->saved_gplr, c->regbase + GPSR_OFFSET);
323		__raw_writel(~c->saved_gplr, c->regbase + GPCR_OFFSET);
324
325		__raw_writel(c->saved_grer, c->regbase + GRER_OFFSET);
326		__raw_writel(c->saved_gfer, c->regbase + GFER_OFFSET);
327		__raw_writel(c->saved_gpdr, c->regbase + GPDR_OFFSET);
328	}
329	return 0;
330}
331#else
332#define pxa_gpio_suspend	NULL
333#define pxa_gpio_resume		NULL
334#endif
335
336struct sysdev_class pxa_gpio_sysclass = {
337	.name		= "gpio",
338	.suspend	= pxa_gpio_suspend,
339	.resume		= pxa_gpio_resume,
340};
341
342static int __init pxa_gpio_init(void)
343{
344	return sysdev_class_register(&pxa_gpio_sysclass);
345}
346
347core_initcall(pxa_gpio_init);
348