1/*
2 * A gpio chip driver for TXx9 SoCs
3 *
4 * Copyright (C) 2008 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10
11#include <linux/init.h>
12#include <linux/spinlock.h>
13#include <linux/gpio.h>
14#include <linux/errno.h>
15#include <linux/io.h>
16#include <asm/txx9pio.h>
17
18static DEFINE_SPINLOCK(txx9_gpio_lock);
19
20static struct txx9_pio_reg __iomem *txx9_pioptr;
21
22static int txx9_gpio_get(struct gpio_chip *chip, unsigned int offset)
23{
24	return __raw_readl(&txx9_pioptr->din) & (1 << offset);
25}
26
27static void txx9_gpio_set_raw(unsigned int offset, int value)
28{
29	u32 val;
30	val = __raw_readl(&txx9_pioptr->dout);
31	if (value)
32		val |= 1 << offset;
33	else
34		val &= ~(1 << offset);
35	__raw_writel(val, &txx9_pioptr->dout);
36}
37
38static void txx9_gpio_set(struct gpio_chip *chip, unsigned int offset,
39			  int value)
40{
41	unsigned long flags;
42	spin_lock_irqsave(&txx9_gpio_lock, flags);
43	txx9_gpio_set_raw(offset, value);
44	mmiowb();
45	spin_unlock_irqrestore(&txx9_gpio_lock, flags);
46}
47
48static int txx9_gpio_dir_in(struct gpio_chip *chip, unsigned int offset)
49{
50	unsigned long flags;
51	spin_lock_irqsave(&txx9_gpio_lock, flags);
52	__raw_writel(__raw_readl(&txx9_pioptr->dir) & ~(1 << offset),
53		     &txx9_pioptr->dir);
54	mmiowb();
55	spin_unlock_irqrestore(&txx9_gpio_lock, flags);
56	return 0;
57}
58
59static int txx9_gpio_dir_out(struct gpio_chip *chip, unsigned int offset,
60			     int value)
61{
62	unsigned long flags;
63	spin_lock_irqsave(&txx9_gpio_lock, flags);
64	txx9_gpio_set_raw(offset, value);
65	__raw_writel(__raw_readl(&txx9_pioptr->dir) | (1 << offset),
66		     &txx9_pioptr->dir);
67	mmiowb();
68	spin_unlock_irqrestore(&txx9_gpio_lock, flags);
69	return 0;
70}
71
72static struct gpio_chip txx9_gpio_chip = {
73	.get = txx9_gpio_get,
74	.set = txx9_gpio_set,
75	.direction_input = txx9_gpio_dir_in,
76	.direction_output = txx9_gpio_dir_out,
77	.label = "TXx9",
78};
79
80int __init txx9_gpio_init(unsigned long baseaddr,
81			  unsigned int base, unsigned int num)
82{
83	txx9_pioptr = ioremap(baseaddr, sizeof(struct txx9_pio_reg));
84	if (!txx9_pioptr)
85		return -ENODEV;
86	txx9_gpio_chip.base = base;
87	txx9_gpio_chip.ngpio = num;
88	return gpiochip_add(&txx9_gpio_chip);
89}
90