aboutsummaryrefslogtreecommitdiffstats
path: root/arch/arm/mach-davinci/gpio.c
blob: bf0ff587e46a15f98c6be4a883e15d448ffa225c (plain) (blame)
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
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
/*
 * TI DaVinci GPIO Support
 *
 * Copyright (c) 2006-2007 David Brownell
 * Copyright (c) 2007, MontaVista Software, Inc. <source@mvista.com>
 *
 * 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/clk.h>
#include <linux/err.h>
#include <linux/io.h>

#include <mach/gpio.h>

#include <asm/mach/irq.h>

struct davinci_gpio_regs {
	u32	dir;
	u32	out_data;
	u32	set_data;
	u32	clr_data;
	u32	in_data;
	u32	set_rising;
	u32	clr_rising;
	u32	set_falling;
	u32	clr_falling;
	u32	intstat;
};

#define chip2controller(chip)	\
	container_of(chip, struct davinci_gpio_controller, chip)

static struct davinci_gpio_controller chips[DIV_ROUND_UP(DAVINCI_N_GPIO, 32)];
static void __iomem *gpio_base;

static struct davinci_gpio_regs __iomem __init *gpio2regs(unsigned gpio)
{
	void __iomem *ptr;

	if (gpio < 32 * 1)
		ptr = gpio_base + 0x10;
	else if (gpio < 32 * 2)
		ptr = gpio_base + 0x38;
	else if (gpio < 32 * 3)
		ptr = gpio_base + 0x60;
	else if (gpio < 32 * 4)
		ptr = gpio_base + 0x88;
	else if (gpio < 32 * 5)
		ptr = gpio_base + 0xb0;
	else
		ptr = NULL;
	return ptr;
}

static inline struct davinci_gpio_regs __iomem *irq2regs(int irq)
{
	struct davinci_gpio_regs __iomem *g;

	g = (__force struct davinci_gpio_regs __iomem *)get_irq_chip_data(irq);

	return g;
}

static int __init davinci_gpio_irq_setup(void);

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

/* board setup code *MUST* setup pinmux and enable the GPIO clock. */
static inline int __davinci_direction(struct gpio_chip *chip,
			unsigned offset, bool out, int value)
{
	struct davinci_gpio_controller *d = chip2controller(chip);
	struct davinci_gpio_regs __iomem *g = d->regs;
	unsigned long flags;
	u32 temp;
	u32 mask = 1 << offset;

	spin_lock_irqsave(&d->lock, flags);
	temp = __raw_readl(&g->dir);
	if (out) {
		temp &= ~mask;
		__raw_writel(mask, value ? &g->set_data : &g->clr_data);
	} else {
		temp |= mask;
	}
	__raw_writel(temp, &g->dir);
	spin_unlock_irqrestore(&d->lock, flags);

	return 0;
}

static int davinci_direction_in(struct gpio_chip *chip, unsigned offset)
{
	return __davinci_direction(chip, offset, false, 0);
}

static int
davinci_direction_out(struct gpio_chip *chip, unsigned offset, int value)
{
	return __davinci_direction(chip, offset, true, value);
}

/*
 * Read the pin's value (works even if it's set up as output);
 * returns zero/nonzero.
 *
 * Note that changes are synched to the GPIO clock, so reading values back
 * right after you've set them may give old values.
 */
static int davinci_gpio_get(struct gpio_chip *chip, unsigned offset)
{
	struct davinci_gpio_controller *d = chip2controller(chip);
	struct davinci_gpio_regs __iomem *g = d->regs;

	return (1 << offset) & __raw_readl(&g->in_data);
}

/*
 * Assuming the pin is muxed as a gpio output, set its output value.
 */
static void
davinci_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
{
	struct davinci_gpio_controller *d = chip2controller(chip);
	struct davinci_gpio_regs __iomem *g = d->regs;

	__raw_writel((1 << offset), value ? &g->set_data : &g->clr_data);
}

static int __init davinci_gpio_setup(void)
{
	int i, base;
	unsigned ngpio;
	struct davinci_soc_info *soc_info = &davinci_soc_info;
	struct davinci_gpio_regs *regs;

	if (soc_info->gpio_type != GPIO_TYPE_DAVINCI)
		return 0;

	/*
	 * The gpio banks conceptually expose a segmented bitmap,
	 * and "ngpio" is one more than the largest zero-based
	 * bit index that's valid.
	 */
	ngpio = soc_info->gpio_num;
	if (ngpio == 0) {
		pr_err("GPIO setup:  how many GPIOs?\n");
		return -EINVAL;
	}

	if (WARN_ON(DAVINCI_N_GPIO < ngpio))
		ngpio = DAVINCI_N_GPIO;

	gpio_base = ioremap(soc_info->gpio_base, SZ_4K);
	if (WARN_ON(!gpio_base))
		return -ENOMEM;

	for (i = 0, base = 0; base < ngpio; i++, base += 32) {
		chips[i].chip.label = "DaVinci";

		chips[i].chip.direction_input = davinci_direction_in;
		chips[i].chip.get = davinci_gpio_get;
		chips[i].chip.direction_output = davinci_direction_out;
		chips[i].chip.set = davinci_gpio_set;

		chips[i].chip.base = base;
		chips[i].chip.ngpio = ngpio - base;
		if (chips[i].chip.ngpio > 32)
			chips[i].chip.ngpio = 32;

		spin_lock_init(&chips[i].lock);

		regs = gpio2regs(base);
		chips[i].regs = regs;
		chips[i].set_data = &regs->set_data;
		chips[i].clr_data = &regs->clr_data;
		chips[i].in_data = &regs->in_data;

		gpiochip_add(&chips[i].chip);
	}

	soc_info->gpio_ctlrs = chips;
	soc_info->gpio_ctlrs_num = DIV_ROUND_UP(ngpio, 32);

	davinci_gpio_irq_setup();
	return 0;
}
pure_initcall(davinci_gpio_setup);

/*--------------------------------------------------------------------------*/
/*
 * We expect irqs will normally be set up as input pins, but they can also be
 * used as output pins ... which is convenient for testing.
 *
 * NOTE:  The first few GPIOs also have direct INTC hookups in addition
 * to their GPIOBNK0 irq, with a bit less overhead.
 *
 * All those INTC hookups (direct, plus several IRQ banks) can also
 * serve as EDMA event triggers.
 */

static void gpio_irq_disable(unsigned irq)
{
	struct davinci_gpio_regs __iomem *g = irq2regs(irq);
	u32 mask = (u32) get_irq_data(irq);

	__raw_writel(mask, &g->clr_falling);
	__raw_writel(mask, &g->clr_rising);
}

static void gpio_irq_enable(unsigned irq)
{
	struct davinci_gpio_regs __iomem *g = irq2regs(irq);
	u32 mask = (u32) get_irq_data(irq);
	unsigned status = irq_desc[irq].status;

	status &= IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING;
	if (!status)
		status = IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING;

	if (status & IRQ_TYPE_EDGE_FALLING)
		__raw_writel(mask, &g->set_falling);
	if (status & IRQ_TYPE_EDGE_RISING)
		__raw_writel(mask, &g->set_rising);
}

static int gpio_irq_type(unsigned irq, unsigned trigger)
{
	struct davinci_gpio_regs __iomem *g = irq2regs(irq);
	u32 mask = (u32) get_irq_data(irq);

	if (trigger & ~(IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING))
		return -EINVAL;

	irq_desc[irq].status &= ~IRQ_TYPE_SENSE_MASK;
	irq_desc[irq].status |= trigger;

	/* don't enable the IRQ if it's currently disabled */
	if (irq_desc[irq].depth == 0) {
		__raw_writel(mask, (trigger & IRQ_TYPE_EDGE_FALLING)
			     ? &g->set_falling : &g->clr_falling);
		__raw_writel(mask, (trigger & IRQ_TYPE_EDGE_RISING)
			     ? &g->set_rising : &g->clr_rising);
	}
	return 0;
}

static struct irq_chip gpio_irqchip = {
	.name		= "GPIO",
	.enable		= gpio_irq_enable,
	.disable	= gpio_irq_disable,
	.set_type	= gpio_irq_type,
};

static void
gpio_irq_handler(unsigned irq, struct irq_desc *desc)
{
	struct davinci_gpio_regs __iomem *g = irq2regs(irq);
	u32 mask = 0xffff;

	/* we only care about one bank */
	if (irq & 1)
		mask <<= 16;

	/* temporarily mask (level sensitive) parent IRQ */
	desc->chip->mask(irq);
	desc->chip->ack(irq);
	while (1) {
		u32		status;
		int		n;
		int		res;

		/* ack any irqs */
		status = __raw_readl(&g->intstat) & mask;
		if (!status)
			break;
		__raw_writel(status, &g->intstat);
		if (irq & 1)
			status >>= 16;

		/* now demux them to the right lowlevel handler */
		n = (int)get_irq_data(irq);
		while (status) {
			res = ffs(status);
			n += res;
			generic_handle_irq(n - 1);
			status >>= res;
		}
	}
	desc->chip->unmask(irq);
	/* now it may re-trigger */
}

static int gpio_to_irq_banked(struct gpio_chip *chip, unsigned offset)
{
	struct davinci_gpio_controller *d = chip2controller(chip);

	if (d->irq_base >= 0)
		return d->irq_base + offset;
	else
		return -ENODEV;
}

static int gpio_to_irq_unbanked(struct gpio_chip *chip, unsigned offset)
{
	struct davinci_soc_info *soc_info = &davinci_soc_info;

	/* NOTE:  we assume for now that only irqs in the first gpio_chip
	 * can provide direct-mapped IRQs to AINTC (up to 32 GPIOs).
	 */
	if (offset < soc_info->gpio_unbanked)
		return soc_info->gpio_irq + offset;
	else
		return -ENODEV;
}

static int gpio_irq_type_unbanked(unsigned irq, unsigned trigger)
{
	struct davinci_gpio_regs __iomem *g = irq2regs(irq);
	u32 mask = (u32) get_irq_data(irq);

	if (trigger & ~(IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING))
		return -EINVAL;

	__raw_writel(mask, (trigger & IRQ_TYPE_EDGE_FALLING)
		     ? &g->set_falling : &g->clr_falling);
	__raw_writel(mask, (trigger & IRQ_TYPE_EDGE_RISING)
		     ? &g->set_rising : &g->clr_rising);

	return 0;
}

/*
 * NOTE:  for suspend/resume, probably best to make a platform_device with
 * suspend_late/resume_resume calls hooking into results of the set_wake()
 * calls ... so if no gpios are wakeup events the clock can be disabled,
 * with outputs left at previously set levels, and so that VDD3P3V.IOPWDN0
 * (dm6446) can be set appropriately for GPIOV33 pins.
 */

static int __init davinci_gpio_irq_setup(void)
{
	unsigned	gpio, irq, bank;
	struct clk	*clk;
	u32		binten = 0;
	unsigned	ngpio, bank_irq;
	struct davinci_soc_info *soc_info = &davinci_soc_info;
	struct davinci_gpio_regs	__iomem *g;

	ngpio = soc_info->gpio_num;

	bank_irq = soc_info->gpio_irq;
	if (bank_irq == 0) {
		printk(KERN_ERR "Don't know first GPIO bank IRQ.\n");
		return -EINVAL;
	}

	clk = clk_get(NULL, "gpio");
	if (IS_ERR(clk)) {
		printk(KERN_ERR "Error %ld getting gpio clock?\n",
		       PTR_ERR(clk));
		return PTR_ERR(clk);
	}
	clk_enable(clk);

	/* Arrange gpio_to_irq() support, handling either direct IRQs or
	 * banked IRQs.  Having GPIOs in the first GPIO bank use direct
	 * IRQs, while the others use banked IRQs, would need some setup
	 * tweaks to recognize hardware which can do that.
	 */
	for (gpio = 0, bank = 0; gpio < ngpio; bank++, gpio += 32) {
		chips[bank].chip.to_irq = gpio_to_irq_banked;
		chips[bank].irq_base = soc_info->gpio_unbanked
			? -EINVAL
			: (soc_info->intc_irq_num + gpio);
	}

	/*
	 * AINTC can handle direct/unbanked IRQs for GPIOs, with the GPIO
	 * controller only handling trigger modes.  We currently assume no
	 * IRQ mux conflicts; gpio_irq_type_unbanked() is only for GPIOs.
	 */
	if (soc_info->gpio_unbanked) {
		static struct irq_chip gpio_irqchip_unbanked;

		/* pass "bank 0" GPIO IRQs to AINTC */
		chips[0].chip.to_irq = gpio_to_irq_unbanked;
		binten = BIT(0);

		/* AINTC handles mask/unmask; GPIO handles triggering */
		irq = bank_irq;
		gpio_irqchip_unbanked = *get_irq_desc_chip(irq_to_desc(irq));
		gpio_irqchip_unbanked.name = "GPIO-AINTC";
		gpio_irqchip_unbanked.set_type = gpio_irq_type_unbanked;

		/* default trigger: both edges */
		g = gpio2regs(0);
		__raw_writel(~0, &g->set_falling);
		__raw_writel(~0, &g->set_rising);

		/* set the direct IRQs up to use that irqchip */
		for (gpio = 0; gpio < soc_info->gpio_unbanked; gpio++, irq++) {
			set_irq_chip(irq, &gpio_irqchip_unbanked);
			set_irq_data(irq, (void *) __gpio_mask(gpio));
			set_irq_chip_data(irq, (__force void *) g);
			irq_desc[irq].status |= IRQ_TYPE_EDGE_BOTH;
		}

		goto done;
	}

	/*
	 * Or, AINTC can handle IRQs for banks of 16 GPIO IRQs, which we
	 * then chain through our own handler.
	 */
	for (gpio = 0, irq = gpio_to_irq(0), bank = 0;
			gpio < ngpio;
			bank++, bank_irq++) {
		unsigned		i;

		/* disabled by default, enabled only as needed */
		g = gpio2regs(gpio);
		__raw_writel(~0, &g->clr_falling);
		__raw_writel(~0, &g->clr_rising);

		/* set up all irqs in this bank */
		set_irq_chained_handler(bank_irq, gpio_irq_handler);
		set_irq_chip_data(bank_irq, (__force void *) g);
		set_irq_data(bank_irq, (void *) irq);

		for (i = 0; i < 16 && gpio < ngpio; i++, irq++, gpio++) {
			set_irq_chip(irq, &gpio_irqchip);
			set_irq_chip_data(irq, (__force void *) g);
			set_irq_data(irq, (void *) __gpio_mask(gpio));
			set_irq_handler(irq, handle_simple_irq);
			set_irq_flags(irq, IRQF_VALID);
		}

		binten |= BIT(bank);
	}

done:
	/* BINTEN -- per-bank interrupt enable. genirq would also let these
	 * bits be set/cleared dynamically.
	 */
	__raw_writel(binten, gpio_base + 0x08);

	printk(KERN_INFO "DaVinci: %d gpio irqs\n", irq - gpio_to_irq(0));

	return 0;
}