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 18 static DEFINE_SPINLOCK(txx9_gpio_lock); 19 20 static struct txx9_pio_reg __iomem *txx9_pioptr; 21 22 static int txx9_gpio_get(struct gpio_chip *chip, unsigned int offset) 23 { 24 return __raw_readl(&txx9_pioptr->din) & (1 << offset); 25 } 26 27 static 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 38 static 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 48 static int txx9_gpio_dir_in(struct gpio_chip *chip, unsigned int offset) 49 { 50 spin_lock_irq(&txx9_gpio_lock); 51 __raw_writel(__raw_readl(&txx9_pioptr->dir) & ~(1 << offset), 52 &txx9_pioptr->dir); 53 mmiowb(); 54 spin_unlock_irq(&txx9_gpio_lock); 55 return 0; 56 } 57 58 static int txx9_gpio_dir_out(struct gpio_chip *chip, unsigned int offset, 59 int value) 60 { 61 spin_lock_irq(&txx9_gpio_lock); 62 txx9_gpio_set_raw(offset, value); 63 __raw_writel(__raw_readl(&txx9_pioptr->dir) | (1 << offset), 64 &txx9_pioptr->dir); 65 mmiowb(); 66 spin_unlock_irq(&txx9_gpio_lock); 67 return 0; 68 } 69 70 static struct gpio_chip txx9_gpio_chip = { 71 .get = txx9_gpio_get, 72 .set = txx9_gpio_set, 73 .direction_input = txx9_gpio_dir_in, 74 .direction_output = txx9_gpio_dir_out, 75 .label = "TXx9", 76 }; 77 78 int __init txx9_gpio_init(unsigned long baseaddr, 79 unsigned int base, unsigned int num) 80 { 81 txx9_pioptr = ioremap(baseaddr, sizeof(struct txx9_pio_reg)); 82 if (!txx9_pioptr) 83 return -ENODEV; 84 txx9_gpio_chip.base = base; 85 txx9_gpio_chip.ngpio = num; 86 return gpiochip_add(&txx9_gpio_chip); 87 } 88