gpio.c

  1/*
  2 * This file is subject to the terms and conditions of the GNU General Public
  3 * License.  See the file "COPYING" in the main directory of this archive
  4 * for more details.
  5 *
  6 * Copyright (C) 2008 Maxime Bizon <mbizon@freebox.fr>
  7 * Copyright (C) 2008-2011 Florian Fainelli <florian@openwrt.org>
  8 */
  9
 10#include <linux/kernel.h>
 11#include <linux/init.h>
 12#include <linux/spinlock.h>
 13#include <linux/platform_device.h>
 14#include <linux/gpio/driver.h>
 15
 16#include <bcm63xx_cpu.h>
 17#include <bcm63xx_gpio.h>
 18#include <bcm63xx_io.h>
 19#include <bcm63xx_regs.h>
 20
 21static u32 gpio_out_low_reg;
 22
 23static void bcm63xx_gpio_out_low_reg_init(void)
 24{
 25	switch (bcm63xx_get_cpu_id()) {
 26	case BCM6345_CPU_ID:
 27		gpio_out_low_reg = GPIO_DATA_LO_REG_6345;
 28		break;
 29	default:
 30		gpio_out_low_reg = GPIO_DATA_LO_REG;
 31		break;
 32	}
 33}
 34
 35static DEFINE_SPINLOCK(bcm63xx_gpio_lock);
 36static u32 gpio_out_low, gpio_out_high;
 37
 38static int bcm63xx_gpio_set(struct gpio_chip *chip, unsigned int gpio, int val)
 39{
 40	u32 reg;
 41	u32 mask;
 42	u32 *v;
 43	unsigned long flags;
 44
 45	BUG_ON(gpio >= chip->ngpio);
 46
 47	if (gpio < 32) {
 48		reg = gpio_out_low_reg;
 49		mask = 1 << gpio;
 50		v = &gpio_out_low;
 51	} else {
 52		reg = GPIO_DATA_HI_REG;
 53		mask = 1 << (gpio - 32);
 54		v = &gpio_out_high;
 55	}
 56
 57	spin_lock_irqsave(&bcm63xx_gpio_lock, flags);
 58	if (val)
 59		*v |= mask;
 60	else
 61		*v &= ~mask;
 62	bcm_gpio_writel(*v, reg);
 63	spin_unlock_irqrestore(&bcm63xx_gpio_lock, flags);
 64
 65	return 0;
 66}
 67
 68static int bcm63xx_gpio_get(struct gpio_chip *chip, unsigned gpio)
 69{
 70	u32 reg;
 71	u32 mask;
 72
 73	BUG_ON(gpio >= chip->ngpio);
 74
 75	if (gpio < 32) {
 76		reg = gpio_out_low_reg;
 77		mask = 1 << gpio;
 78	} else {
 79		reg = GPIO_DATA_HI_REG;
 80		mask = 1 << (gpio - 32);
 81	}
 82
 83	return !!(bcm_gpio_readl(reg) & mask);
 84}
 85
 86static int bcm63xx_gpio_set_direction(struct gpio_chip *chip,
 87				      unsigned gpio, int dir)
 88{
 89	u32 reg;
 90	u32 mask;
 91	u32 tmp;
 92	unsigned long flags;
 93
 94	BUG_ON(gpio >= chip->ngpio);
 95
 96	if (gpio < 32) {
 97		reg = GPIO_CTL_LO_REG;
 98		mask = 1 << gpio;
 99	} else {
100		reg = GPIO_CTL_HI_REG;
101		mask = 1 << (gpio - 32);
102	}
103
104	spin_lock_irqsave(&bcm63xx_gpio_lock, flags);
105	tmp = bcm_gpio_readl(reg);
106	if (dir == BCM63XX_GPIO_DIR_IN)
107		tmp &= ~mask;
108	else
109		tmp |= mask;
110	bcm_gpio_writel(tmp, reg);
111	spin_unlock_irqrestore(&bcm63xx_gpio_lock, flags);
112
113	return 0;
114}
115
116static int bcm63xx_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
117{
118	return bcm63xx_gpio_set_direction(chip, gpio, BCM63XX_GPIO_DIR_IN);
119}
120
121static int bcm63xx_gpio_direction_output(struct gpio_chip *chip,
122					 unsigned gpio, int value)
123{
124	bcm63xx_gpio_set(chip, gpio, value);
125	return bcm63xx_gpio_set_direction(chip, gpio, BCM63XX_GPIO_DIR_OUT);
126}
127
128
129static struct gpio_chip bcm63xx_gpio_chip = {
130	.label			= "bcm63xx-gpio",
131	.direction_input	= bcm63xx_gpio_direction_input,
132	.direction_output	= bcm63xx_gpio_direction_output,
133	.get			= bcm63xx_gpio_get,
134	.set			= bcm63xx_gpio_set,
135	.base			= 0,
136};
137
138int __init bcm63xx_gpio_init(void)
139{
140	bcm63xx_gpio_out_low_reg_init();
141
142	gpio_out_low = bcm_gpio_readl(gpio_out_low_reg);
143	if (!BCMCPU_IS_6345())
144		gpio_out_high = bcm_gpio_readl(GPIO_DATA_HI_REG);
145	bcm63xx_gpio_chip.ngpio = bcm63xx_gpio_count();
146	pr_info("registering %d GPIOs\n", bcm63xx_gpio_chip.ngpio);
147
148	return gpiochip_add_data(&bcm63xx_gpio_chip, NULL);
149}