aboutsummaryrefslogtreecommitdiffstats
path: root/arch/arm/mach-at91rm9200/gpio.c
blob: a9f718bf8ba873f064d4f58c10a8884378670ddf (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
/*
 * linux/arch/arm/mach-at91rm9200/gpio.c
 *
 * Copyright (C) 2005 HP Labs
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/module.h>

#include <asm/io.h>
#include <asm/mach/irq.h>
#include <asm/arch/hardware.h>
#include <asm/arch/gpio.h>

static const u32 pio_controller_offset[4] = {
	AT91_PIOA,
	AT91_PIOB,
	AT91_PIOC,
	AT91_PIOD,
};

static inline void __iomem *pin_to_controller(unsigned pin)
{
	void __iomem *sys_base = (void __iomem *) AT91_VA_BASE_SYS;

	pin -= PIN_BASE;
	pin /= 32;
	if (likely(pin < BGA_GPIO_BANKS))
		return sys_base + pio_controller_offset[pin];

	return NULL;
}

static inline unsigned pin_to_mask(unsigned pin)
{
	pin -= PIN_BASE;
	return 1 << (pin % 32);
}


/*--------------------------------------------------------------------------*/

/* Not all hardware capabilities are exposed through these calls; they
 * only encapsulate the most common features and modes.  (So if you
 * want to change signals in groups, do it directly.)
 *
 * Bootloaders will usually handle some of the pin multiplexing setup.
 * The intent is certainly that by the time Linux is fully booted, all
 * pins should have been fully initialized.  These setup calls should
 * only be used by board setup routines, or possibly in driver probe().
 *
 * For bootloaders doing all that setup, these calls could be inlined
 * as NOPs so Linux won't duplicate any setup code
 */


/*
 * mux the pin to the "A" internal peripheral role.
 */
int __init_or_module at91_set_A_periph(unsigned pin, int use_pullup)
{
	void __iomem	*pio = pin_to_controller(pin);
	unsigned	mask = pin_to_mask(pin);

	if (!pio)
		return -EINVAL;

	__raw_writel(mask, pio + PIO_IDR);
	__raw_writel(mask, pio + (use_pullup ? PIO_PUER : PIO_PUDR));
	__raw_writel(mask, pio + PIO_ASR);
	__raw_writel(mask, pio + PIO_PDR);
	return 0;
}
EXPORT_SYMBOL(at91_set_A_periph);


/*
 * mux the pin to the "B" internal peripheral role.
 */
int __init_or_module at91_set_B_periph(unsigned pin, int use_pullup)
{
	void __iomem	*pio = pin_to_controller(pin);
	unsigned	mask = pin_to_mask(pin);

	if (!pio)
		return -EINVAL;

	__raw_writel(mask, pio + PIO_IDR);
	__raw_writel(mask, pio + (use_pullup ? PIO_PUER : PIO_PUDR));
	__raw_writel(mask, pio + PIO_BSR);
	__raw_writel(mask, pio + PIO_PDR);
	return 0;
}
EXPORT_SYMBOL(at91_set_B_periph);


/*
 * mux the pin to the gpio controller (instead of "A" or "B" peripheral), and
 * configure it for an input.
 */
int __init_or_module at91_set_gpio_input(unsigned pin, int use_pullup)
{
	void __iomem	*pio = pin_to_controller(pin);
	unsigned	mask = pin_to_mask(pin);

	if (!pio)
		return -EINVAL;

	__raw_writel(mask, pio + PIO_IDR);
	__raw_writel(mask, pio + (use_pullup ? PIO_PUER : PIO_PUDR));
	__raw_writel(mask, pio + PIO_ODR);
	__raw_writel(mask, pio + PIO_PER);
	return 0;
}
EXPORT_SYMBOL(at91_set_gpio_input);


/*
 * mux the pin to the gpio controller (instead of "A" or "B" peripheral),
 * and configure it for an output.
 */
int __init_or_module at91_set_gpio_output(unsigned pin, int value)
{
	void __iomem	*pio = pin_to_controller(pin);
	unsigned	mask = pin_to_mask(pin);

	if (!pio)
		return -EINVAL;

	__raw_writel(mask, pio + PIO_IDR);
	__raw_writel(mask, pio + PIO_PUDR);
	__raw_writel(mask, pio + (value ? PIO_SODR : PIO_CODR));
	__raw_writel(mask, pio + PIO_OER);
	__raw_writel(mask, pio + PIO_PER);
	return 0;
}
EXPORT_SYMBOL(at91_set_gpio_output);


/*
 * enable/disable the glitch filter; mostly used with IRQ handling.
 */
int __init_or_module at91_set_deglitch(unsigned pin, int is_on)
{
	void __iomem	*pio = pin_to_controller(pin);
	unsigned	mask = pin_to_mask(pin);

	if (!pio)
		return -EINVAL;
	__raw_writel(mask, pio + (is_on ? PIO_IFER : PIO_IFDR));
	return 0;
}
EXPORT_SYMBOL(at91_set_deglitch);

/*
 * enable/disable the multi-driver; This is only valid for output and
 * allows the output pin to run as an open collector output.
 */
int __init_or_module at91_set_multi_drive(unsigned pin, int is_on)
{
	void __iomem	*pio = pin_to_controller(pin);
	unsigned	mask = pin_to_mask(pin);

	if (!pio)
		return -EINVAL;

	__raw_writel(mask, pio + (is_on ? PIO_MDER : PIO_MDDR));
	return 0;
}
EXPORT_SYMBOL(at91_set_multi_drive);

/*--------------------------------------------------------------------------*/


/*
 * assuming the pin is muxed as a gpio output, set its value.
 */
int at91_set_gpio_value(unsigned pin, int value)
{
	void __iomem	*pio = pin_to_controller(pin);
	unsigned	mask = pin_to_mask(pin);

	if (!pio)
		return -EINVAL;
	__raw_writel(mask, pio + (value ? PIO_SODR : PIO_CODR));
	return 0;
}
EXPORT_SYMBOL(at91_set_gpio_value);


/*
 * read the pin's value (works even if it's not muxed as a gpio).
 */
int at91_get_gpio_value(unsigned pin)
{
	void __iomem	*pio = pin_to_controller(pin);
	unsigned	mask = pin_to_mask(pin);
	u32		pdsr;

	if (!pio)
		return -EINVAL;
	pdsr = __raw_readl(pio + PIO_PDSR);
	return (pdsr & mask) != 0;
}
EXPORT_SYMBOL(at91_get_gpio_value);

/*--------------------------------------------------------------------------*/


/* Several AIC controller irqs are dispatched through this GPIO handler.
 * To use any AT91_PIN_* as an externally triggered IRQ, first call
 * at91_set_gpio_input() then maybe enable its glitch filter.
 * Then just request_irq() with the pin ID; it works like any ARM IRQ
 * handler, though it always triggers on rising and falling edges.
 *
 * Alternatively, certain pins may be used directly as IRQ0..IRQ6 after
 * configuring them with at91_set_a_periph() or at91_set_b_periph().
 * IRQ0..IRQ6 should be configurable, e.g. level vs edge triggering.
 */

static void gpio_irq_mask(unsigned pin)
{
	void __iomem	*pio = pin_to_controller(pin);
	unsigned	mask = pin_to_mask(pin);

	if (pio)
		__raw_writel(mask, pio + PIO_IDR);
}

static void gpio_irq_unmask(unsigned pin)
{
	void __iomem	*pio = pin_to_controller(pin);
	unsigned	mask = pin_to_mask(pin);

	if (pio)
		__raw_writel(mask, pio + PIO_IER);
}

static int gpio_irq_type(unsigned pin, unsigned type)
{
	return (type == IRQT_BOTHEDGE) ? 0 : -EINVAL;
}

static struct irqchip gpio_irqchip = {
	.mask		= gpio_irq_mask,
	.unmask		= gpio_irq_unmask,
	.set_type	= gpio_irq_type,
};

static void gpio_irq_handler(unsigned irq, struct irqdesc *desc, struct pt_regs *regs)
{
	unsigned	pin;
	struct irqdesc	*gpio;
	void __iomem	*pio;
	u32		isr;

	pio = (void __force __iomem *) desc->chipdata;

	/* temporarily mask (level sensitive) parent IRQ */
	desc->chip->ack(irq);
	for (;;) {
		isr = __raw_readl(pio + PIO_ISR) & __raw_readl(pio + PIO_IMR);
		if (!isr)
			break;

		pin = (unsigned) desc->data;
		gpio = &irq_desc[pin];

		while (isr) {
			if (isr & 1)
				gpio->handle(pin, gpio, regs);
			pin++;
			gpio++;
			isr >>= 1;
		}
	}
	desc->chip->unmask(irq);
	/* now it may re-trigger */
}

/* call this from board-specific init_irq */
void __init at91_gpio_irq_setup(unsigned banks)
{
	unsigned	pioc, pin, id;

	if (banks > 4)
		banks = 4;
	for (pioc = 0, pin = PIN_BASE, id = AT91_ID_PIOA;
			pioc < banks;
			pioc++, id++) {
		void __iomem	*controller;
		unsigned	i;

		controller = (void __iomem *) AT91_VA_BASE_SYS + pio_controller_offset[pioc];
		__raw_writel(~0, controller + PIO_IDR);

		set_irq_data(id, (void *) pin);
		set_irq_chipdata(id, (void __force *) controller);

		for (i = 0; i < 32; i++, pin++) {
			set_irq_chip(pin, &gpio_irqchip);
			set_irq_handler(pin, do_simple_IRQ);
			set_irq_flags(pin, IRQF_VALID);
		}

		set_irq_chained_handler(id, gpio_irq_handler);

		/* enable the PIO peripheral clock */
		at91_sys_write(AT91_PMC_PCER, 1 << id);
	}
	pr_info("AT91: %d gpio irqs in %d banks\n", pin - PIN_BASE, banks);
}