gpio_txx9.c

 1// SPDX-License-Identifier: GPL-2.0-only
 2/*
 3 * A gpio chip driver for TXx9 SoCs
 4 *
 5 * Copyright (C) 2008 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
 6 */
 7
 8#include <linux/init.h>
 9#include <linux/spinlock.h>
10#include <linux/gpio/driver.h>
11#include <linux/errno.h>
12#include <linux/io.h>
13#include <asm/txx9pio.h>
14
15static DEFINE_SPINLOCK(txx9_gpio_lock);
16
17static struct txx9_pio_reg __iomem *txx9_pioptr;
18
19static int txx9_gpio_get(struct gpio_chip *chip, unsigned int offset)
20{
21	return !!(__raw_readl(&txx9_pioptr->din) & (1 << offset));
22}
23
24static void txx9_gpio_set_raw(unsigned int offset, int value)
25{
26	u32 val;
27	val = __raw_readl(&txx9_pioptr->dout);
28	if (value)
29		val |= 1 << offset;
30	else
31		val &= ~(1 << offset);
32	__raw_writel(val, &txx9_pioptr->dout);
33}
34
35static int txx9_gpio_set(struct gpio_chip *chip, unsigned int offset,
36			 int value)
37{
38	unsigned long flags;
39	spin_lock_irqsave(&txx9_gpio_lock, flags);
40	txx9_gpio_set_raw(offset, value);
41	mmiowb();
42	spin_unlock_irqrestore(&txx9_gpio_lock, flags);
43
44	return 0;
45}
46
47static int txx9_gpio_dir_in(struct gpio_chip *chip, unsigned int offset)
48{
49	unsigned long flags;
50	spin_lock_irqsave(&txx9_gpio_lock, flags);
51	__raw_writel(__raw_readl(&txx9_pioptr->dir) & ~(1 << offset),
52		     &txx9_pioptr->dir);
53	mmiowb();
54	spin_unlock_irqrestore(&txx9_gpio_lock, flags);
55	return 0;
56}
57
58static int txx9_gpio_dir_out(struct gpio_chip *chip, unsigned int offset,
59			     int value)
60{
61	unsigned long flags;
62	spin_lock_irqsave(&txx9_gpio_lock, flags);
63	txx9_gpio_set_raw(offset, value);
64	__raw_writel(__raw_readl(&txx9_pioptr->dir) | (1 << offset),
65		     &txx9_pioptr->dir);
66	mmiowb();
67	spin_unlock_irqrestore(&txx9_gpio_lock, flags);
68	return 0;
69}
70
71static struct gpio_chip txx9_gpio_chip = {
72	.get = txx9_gpio_get,
73	.set = txx9_gpio_set,
74	.direction_input = txx9_gpio_dir_in,
75	.direction_output = txx9_gpio_dir_out,
76	.label = "TXx9",
77};
78
79int __init txx9_gpio_init(unsigned long baseaddr,
80			  unsigned int base, unsigned int num)
81{
82	txx9_pioptr = ioremap(baseaddr, sizeof(struct txx9_pio_reg));
83	if (!txx9_pioptr)
84		return -ENODEV;
85	txx9_gpio_chip.base = base;
86	txx9_gpio_chip.ngpio = num;
87	return gpiochip_add_data(&txx9_gpio_chip, NULL);
88}