mips/kernel/gpio_txx9.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * A gpio chip driver for TXx9 SoCs
0004  *
0005  * Copyright (C) 2008 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
0006  */
0007
0008 #include <linux/init.h>
0009 #include <linux/spinlock.h>
0010 #include <linux/gpio/driver.h>
0011 #include <linux/errno.h>
0012 #include <linux/io.h>
0013 #include <asm/txx9pio.h>
0014
0015 static DEFINE_SPINLOCK(txx9_gpio_lock);
0016
0017 static struct txx9_pio_reg __iomem *txx9_pioptr;
0018
0019 static int txx9_gpio_get(struct gpio_chip *chip, unsigned int offset)
0020 {
0021     return !!(__raw_readl(&txx9_pioptr->din) & (1 << offset));
0022 }
0023
0024 static void txx9_gpio_set_raw(unsigned int offset, int value)
0025 {
0026     u32 val;
0027     val = __raw_readl(&txx9_pioptr->dout);
0028     if (value)
0029         val |= 1 << offset;
0030     else
0031         val &= ~(1 << offset);
0032     __raw_writel(val, &txx9_pioptr->dout);
0033 }
0034
0035 static void txx9_gpio_set(struct gpio_chip *chip, unsigned int offset,
0036               int value)
0037 {
0038     unsigned long flags;
0039     spin_lock_irqsave(&txx9_gpio_lock, flags);
0040     txx9_gpio_set_raw(offset, value);
0041     mmiowb();
0042     spin_unlock_irqrestore(&txx9_gpio_lock, flags);
0043 }
0044
0045 static int txx9_gpio_dir_in(struct gpio_chip *chip, unsigned int offset)
0046 {
0047     unsigned long flags;
0048     spin_lock_irqsave(&txx9_gpio_lock, flags);
0049     __raw_writel(__raw_readl(&txx9_pioptr->dir) & ~(1 << offset),
0050              &txx9_pioptr->dir);
0051     mmiowb();
0052     spin_unlock_irqrestore(&txx9_gpio_lock, flags);
0053     return 0;
0054 }
0055
0056 static int txx9_gpio_dir_out(struct gpio_chip *chip, unsigned int offset,
0057                  int value)
0058 {
0059     unsigned long flags;
0060     spin_lock_irqsave(&txx9_gpio_lock, flags);
0061     txx9_gpio_set_raw(offset, value);
0062     __raw_writel(__raw_readl(&txx9_pioptr->dir) | (1 << offset),
0063              &txx9_pioptr->dir);
0064     mmiowb();
0065     spin_unlock_irqrestore(&txx9_gpio_lock, flags);
0066     return 0;
0067 }
0068
0069 static struct gpio_chip txx9_gpio_chip = {
0070     .get = txx9_gpio_get,
0071     .set = txx9_gpio_set,
0072     .direction_input = txx9_gpio_dir_in,
0073     .direction_output = txx9_gpio_dir_out,
0074     .label = "TXx9",
0075 };
0076
0077 int __init txx9_gpio_init(unsigned long baseaddr,
0078               unsigned int base, unsigned int num)
0079 {
0080     txx9_pioptr = ioremap(baseaddr, sizeof(struct txx9_pio_reg));
0081     if (!txx9_pioptr)
0082         return -ENODEV;
0083     txx9_gpio_chip.base = base;
0084     txx9_gpio_chip.ngpio = num;
0085     return gpiochip_add_data(&txx9_gpio_chip, NULL);
0086 }