linux/arch/mips/bcm63xx/gpio.c
zhouchuangao 7e9be673cb MIPS: BCM63XX: Use BUG_ON instead of condition followed by BUG.
BUG_ON uses unlikely in if(), it can be optimized at compile time.

Usually, the condition in if() is not satisfied. In my opinion,
this can improve the efficiency of the multi-stage pipeline.

Signed-off-by: zhouchuangao <zhouchuangao@vivo.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
2021-04-26 10:23:52 +02:00

149 lines
3.2 KiB
C

/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2008 Maxime Bizon <mbizon@freebox.fr>
* Copyright (C) 2008-2011 Florian Fainelli <florian@openwrt.org>
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/platform_device.h>
#include <linux/gpio/driver.h>
#include <bcm63xx_cpu.h>
#include <bcm63xx_gpio.h>
#include <bcm63xx_io.h>
#include <bcm63xx_regs.h>
static u32 gpio_out_low_reg;
static void bcm63xx_gpio_out_low_reg_init(void)
{
switch (bcm63xx_get_cpu_id()) {
case BCM6345_CPU_ID:
gpio_out_low_reg = GPIO_DATA_LO_REG_6345;
break;
default:
gpio_out_low_reg = GPIO_DATA_LO_REG;
break;
}
}
static DEFINE_SPINLOCK(bcm63xx_gpio_lock);
static u32 gpio_out_low, gpio_out_high;
static void bcm63xx_gpio_set(struct gpio_chip *chip,
unsigned gpio, int val)
{
u32 reg;
u32 mask;
u32 *v;
unsigned long flags;
BUG_ON(gpio >= chip->ngpio);
if (gpio < 32) {
reg = gpio_out_low_reg;
mask = 1 << gpio;
v = &gpio_out_low;
} else {
reg = GPIO_DATA_HI_REG;
mask = 1 << (gpio - 32);
v = &gpio_out_high;
}
spin_lock_irqsave(&bcm63xx_gpio_lock, flags);
if (val)
*v |= mask;
else
*v &= ~mask;
bcm_gpio_writel(*v, reg);
spin_unlock_irqrestore(&bcm63xx_gpio_lock, flags);
}
static int bcm63xx_gpio_get(struct gpio_chip *chip, unsigned gpio)
{
u32 reg;
u32 mask;
BUG_ON(gpio >= chip->ngpio);
if (gpio < 32) {
reg = gpio_out_low_reg;
mask = 1 << gpio;
} else {
reg = GPIO_DATA_HI_REG;
mask = 1 << (gpio - 32);
}
return !!(bcm_gpio_readl(reg) & mask);
}
static int bcm63xx_gpio_set_direction(struct gpio_chip *chip,
unsigned gpio, int dir)
{
u32 reg;
u32 mask;
u32 tmp;
unsigned long flags;
BUG_ON(gpio >= chip->ngpio);
if (gpio < 32) {
reg = GPIO_CTL_LO_REG;
mask = 1 << gpio;
} else {
reg = GPIO_CTL_HI_REG;
mask = 1 << (gpio - 32);
}
spin_lock_irqsave(&bcm63xx_gpio_lock, flags);
tmp = bcm_gpio_readl(reg);
if (dir == BCM63XX_GPIO_DIR_IN)
tmp &= ~mask;
else
tmp |= mask;
bcm_gpio_writel(tmp, reg);
spin_unlock_irqrestore(&bcm63xx_gpio_lock, flags);
return 0;
}
static int bcm63xx_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
{
return bcm63xx_gpio_set_direction(chip, gpio, BCM63XX_GPIO_DIR_IN);
}
static int bcm63xx_gpio_direction_output(struct gpio_chip *chip,
unsigned gpio, int value)
{
bcm63xx_gpio_set(chip, gpio, value);
return bcm63xx_gpio_set_direction(chip, gpio, BCM63XX_GPIO_DIR_OUT);
}
static struct gpio_chip bcm63xx_gpio_chip = {
.label = "bcm63xx-gpio",
.direction_input = bcm63xx_gpio_direction_input,
.direction_output = bcm63xx_gpio_direction_output,
.get = bcm63xx_gpio_get,
.set = bcm63xx_gpio_set,
.base = 0,
};
int __init bcm63xx_gpio_init(void)
{
bcm63xx_gpio_out_low_reg_init();
gpio_out_low = bcm_gpio_readl(gpio_out_low_reg);
if (!BCMCPU_IS_6345())
gpio_out_high = bcm_gpio_readl(GPIO_DATA_HI_REG);
bcm63xx_gpio_chip.ngpio = bcm63xx_gpio_count();
pr_info("registering %d GPIOs\n", bcm63xx_gpio_chip.ngpio);
return gpiochip_add_data(&bcm63xx_gpio_chip, NULL);
}