diff options
Diffstat (limited to 'arch/arm/plat-orion/gpio.c')
| -rw-r--r-- | arch/arm/plat-orion/gpio.c | 239 |
1 files changed, 239 insertions, 0 deletions
diff --git a/arch/arm/plat-orion/gpio.c b/arch/arm/plat-orion/gpio.c new file mode 100644 index 000000000000..d86fc085e489 --- /dev/null +++ b/arch/arm/plat-orion/gpio.c @@ -0,0 +1,239 @@ +/* + * arch/arm/plat-orion/gpio.c + * + * Marvell Orion SoC GPIO handling. + * + * This file is licensed under the terms of the GNU General Public + * License version 2. This program is licensed "as is" without any + * warranty of any kind, whether express or implied. + */ + +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/module.h> +#include <linux/spinlock.h> +#include <linux/bitops.h> +#include <linux/io.h> +#include <asm/gpio.h> + +static DEFINE_SPINLOCK(gpio_lock); +static const char *gpio_label[GPIO_MAX]; /* non null for allocated GPIOs */ +static unsigned long gpio_valid[BITS_TO_LONGS(GPIO_MAX)]; + +static inline void __set_direction(unsigned pin, int input) +{ + u32 u; + + u = readl(GPIO_IO_CONF(pin)); + if (input) + u |= 1 << (pin & 31); + else + u &= ~(1 << (pin & 31)); + writel(u, GPIO_IO_CONF(pin)); +} + +static void __set_level(unsigned pin, int high) +{ + u32 u; + + u = readl(GPIO_OUT(pin)); + if (high) + u |= 1 << (pin & 31); + else + u &= ~(1 << (pin & 31)); + writel(u, GPIO_OUT(pin)); +} + + +/* + * GENERIC_GPIO primitives. + */ +int gpio_direction_input(unsigned pin) +{ + unsigned long flags; + + if (pin >= GPIO_MAX || !test_bit(pin, gpio_valid)) { + pr_debug("%s: invalid GPIO %d\n", __func__, pin); + return -EINVAL; + } + + spin_lock_irqsave(&gpio_lock, flags); + + /* + * Some callers might not have used gpio_request(), + * so flag this pin as requested now. + */ + if (gpio_label[pin] == NULL) + gpio_label[pin] = "?"; + + /* + * Configure GPIO direction. + */ + __set_direction(pin, 1); + + spin_unlock_irqrestore(&gpio_lock, flags); + + return 0; +} +EXPORT_SYMBOL(gpio_direction_input); + +int gpio_direction_output(unsigned pin, int value) +{ + unsigned long flags; + u32 u; + + if (pin >= GPIO_MAX || !test_bit(pin, gpio_valid)) { + pr_debug("%s: invalid GPIO %d\n", __func__, pin); + return -EINVAL; + } + + spin_lock_irqsave(&gpio_lock, flags); + + /* + * Some callers might not have used gpio_request(), + * so flag this pin as requested now. + */ + if (gpio_label[pin] == NULL) + gpio_label[pin] = "?"; + + /* + * Disable blinking. + */ + u = readl(GPIO_BLINK_EN(pin)); + u &= ~(1 << (pin & 31)); + writel(u, GPIO_BLINK_EN(pin)); + + /* + * Configure GPIO output value. + */ + __set_level(pin, value); + + /* + * Configure GPIO direction. + */ + __set_direction(pin, 0); + + spin_unlock_irqrestore(&gpio_lock, flags); + + return 0; +} +EXPORT_SYMBOL(gpio_direction_output); + +int gpio_get_value(unsigned pin) +{ + int val; + + if (readl(GPIO_IO_CONF(pin)) & (1 << (pin & 31))) + val = readl(GPIO_DATA_IN(pin)) ^ readl(GPIO_IN_POL(pin)); + else + val = readl(GPIO_OUT(pin)); + + return (val >> (pin & 31)) & 1; +} +EXPORT_SYMBOL(gpio_get_value); + +void gpio_set_value(unsigned pin, int value) +{ + unsigned long flags; + u32 u; + + spin_lock_irqsave(&gpio_lock, flags); + + /* + * Disable blinking. + */ + u = readl(GPIO_BLINK_EN(pin)); + u &= ~(1 << (pin & 31)); + writel(u, GPIO_BLINK_EN(pin)); + + /* + * Configure GPIO output value. + */ + __set_level(pin, value); + + spin_unlock_irqrestore(&gpio_lock, flags); +} +EXPORT_SYMBOL(gpio_set_value); + +int gpio_request(unsigned pin, const char *label) +{ + unsigned long flags; + int ret; + + if (pin >= GPIO_MAX || !test_bit(pin, gpio_valid)) { + pr_debug("%s: invalid GPIO %d\n", __func__, pin); + return -EINVAL; + } + + spin_lock_irqsave(&gpio_lock, flags); + if (gpio_label[pin] == NULL) { + gpio_label[pin] = label ? label : "?"; + ret = 0; + } else { + pr_debug("%s: GPIO %d already used as %s\n", + __func__, pin, gpio_label[pin]); + ret = -EBUSY; + } + spin_unlock_irqrestore(&gpio_lock, flags); + + return ret; +} +EXPORT_SYMBOL(gpio_request); + +void gpio_free(unsigned pin) +{ + if (pin >= GPIO_MAX || !test_bit(pin, gpio_valid)) { + pr_debug("%s: invalid GPIO %d\n", __func__, pin); + return; + } + + if (gpio_label[pin] == NULL) + pr_warning("%s: GPIO %d already freed\n", __func__, pin); + else + gpio_label[pin] = NULL; +} +EXPORT_SYMBOL(gpio_free); + + +/* + * Orion-specific GPIO API extensions. + */ +void __init orion_gpio_set_unused(unsigned pin) +{ + /* + * Configure as output, drive low. + */ + __set_level(pin, 0); + __set_direction(pin, 0); +} + +void __init orion_gpio_set_valid(unsigned pin, int valid) +{ + if (valid) + __set_bit(pin, gpio_valid); + else + __clear_bit(pin, gpio_valid); +} + +void orion_gpio_set_blink(unsigned pin, int blink) +{ + unsigned long flags; + u32 u; + + spin_lock_irqsave(&gpio_lock, flags); + + /* + * Set output value to zero. + */ + __set_level(pin, 0); + + u = readl(GPIO_BLINK_EN(pin)); + if (blink) + u |= 1 << (pin & 31); + else + u &= ~(1 << (pin & 31)); + writel(u, GPIO_BLINK_EN(pin)); + + spin_unlock_irqrestore(&gpio_lock, flags); +} +EXPORT_SYMBOL(orion_gpio_set_blink); |