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/driver.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 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 59 static 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 72 static 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 80 int __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_data(&txx9_gpio_chip, NULL); 89 } 90