diff options
Diffstat (limited to 'arch/arm/plat-orion')
| -rw-r--r-- | arch/arm/plat-orion/Makefile | 2 | ||||
| -rw-r--r-- | arch/arm/plat-orion/gpio.c | 415 | ||||
| -rw-r--r-- | arch/arm/plat-orion/include/plat/gpio.h | 39 |
3 files changed, 456 insertions, 0 deletions
diff --git a/arch/arm/plat-orion/Makefile b/arch/arm/plat-orion/Makefile index 198f3dde2be3..56021a72e10c 100644 --- a/arch/arm/plat-orion/Makefile +++ b/arch/arm/plat-orion/Makefile @@ -6,3 +6,5 @@ obj-y := irq.o pcie.o time.o obj-m := obj-n := obj- := + +obj-$(CONFIG_GENERIC_GPIO) += gpio.o diff --git a/arch/arm/plat-orion/gpio.c b/arch/arm/plat-orion/gpio.c new file mode 100644 index 000000000000..967186425ca1 --- /dev/null +++ b/arch/arm/plat-orion/gpio.c @@ -0,0 +1,415 @@ +/* + * 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/irq.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); + + +/***************************************************************************** + * Orion GPIO IRQ + * + * GPIO_IN_POL register controls whether GPIO_DATA_IN will hold the same + * value of the line or the opposite value. + * + * Level IRQ handlers: DATA_IN is used directly as cause register. + * Interrupt are masked by LEVEL_MASK registers. + * Edge IRQ handlers: Change in DATA_IN are latched in EDGE_CAUSE. + * Interrupt are masked by EDGE_MASK registers. + * Both-edge handlers: Similar to regular Edge handlers, but also swaps + * the polarity to catch the next line transaction. + * This is a race condition that might not perfectly + * work on some use cases. + * + * Every eight GPIO lines are grouped (OR'ed) before going up to main + * cause register. + * + * EDGE cause mask + * data-in /--------| |-----| |----\ + * -----| |----- ---- to main cause reg + * X \----------------| |----/ + * polarity LEVEL mask + * + ****************************************************************************/ +static void gpio_irq_edge_ack(u32 irq) +{ + int pin = irq_to_gpio(irq); + + writel(~(1 << (pin & 31)), GPIO_EDGE_CAUSE(pin)); +} + +static void gpio_irq_edge_mask(u32 irq) +{ + int pin = irq_to_gpio(irq); + u32 u; + + u = readl(GPIO_EDGE_MASK(pin)); + u &= ~(1 << (pin & 31)); + writel(u, GPIO_EDGE_MASK(pin)); +} + +static void gpio_irq_edge_unmask(u32 irq) +{ + int pin = irq_to_gpio(irq); + u32 u; + + u = readl(GPIO_EDGE_MASK(pin)); + u |= 1 << (pin & 31); + writel(u, GPIO_EDGE_MASK(pin)); +} + +static void gpio_irq_level_mask(u32 irq) +{ + int pin = irq_to_gpio(irq); + u32 u; + + u = readl(GPIO_LEVEL_MASK(pin)); + u &= ~(1 << (pin & 31)); + writel(u, GPIO_LEVEL_MASK(pin)); +} + +static void gpio_irq_level_unmask(u32 irq) +{ + int pin = irq_to_gpio(irq); + u32 u; + + u = readl(GPIO_LEVEL_MASK(pin)); + u |= 1 << (pin & 31); + writel(u, GPIO_LEVEL_MASK(pin)); +} + +static int gpio_irq_set_type(u32 irq, u32 type) +{ + int pin = irq_to_gpio(irq); + struct irq_desc *desc; + u32 u; + + u = readl(GPIO_IO_CONF(pin)) & (1 << (pin & 31)); + if (!u) { + printk(KERN_ERR "orion gpio_irq_set_type failed " + "(irq %d, pin %d).\n", irq, pin); + return -EINVAL; + } + + desc = irq_desc + irq; + + /* + * Set edge/level type. + */ + if (type & (IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING)) { + desc->chip = &orion_gpio_irq_edge_chip; + } else if (type & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW)) { + desc->chip = &orion_gpio_irq_level_chip; + } else { + printk(KERN_ERR "failed to set irq=%d (type=%d)\n", irq, type); + return -EINVAL; + } + + /* + * Configure interrupt polarity. + */ + if (type == IRQ_TYPE_EDGE_RISING || type == IRQ_TYPE_LEVEL_HIGH) { + u = readl(GPIO_IN_POL(pin)); + u &= ~(1 << (pin & 31)); + writel(u, GPIO_IN_POL(pin)); + } else if (type == IRQ_TYPE_EDGE_FALLING || type == IRQ_TYPE_LEVEL_LOW) { + u = readl(GPIO_IN_POL(pin)); + u |= 1 << (pin & 31); + writel(u, GPIO_IN_POL(pin)); + } else if (type == IRQ_TYPE_EDGE_BOTH) { + u32 v; + + v = readl(GPIO_IN_POL(pin)) ^ readl(GPIO_DATA_IN(pin)); + + /* + * set initial polarity based on current input level + */ + u = readl(GPIO_IN_POL(pin)); + if (v & (1 << (pin & 31))) + u |= 1 << (pin & 31); /* falling */ + else + u &= ~(1 << (pin & 31)); /* rising */ + writel(u, GPIO_IN_POL(pin)); + } + + desc->status = (desc->status & ~IRQ_TYPE_SENSE_MASK) | type; + + return 0; +} + +struct irq_chip orion_gpio_irq_edge_chip = { + .name = "orion_gpio_irq_edge", + .ack = gpio_irq_edge_ack, + .mask = gpio_irq_edge_mask, + .unmask = gpio_irq_edge_unmask, + .set_type = gpio_irq_set_type, +}; + +struct irq_chip orion_gpio_irq_level_chip = { + .name = "orion_gpio_irq_level", + .mask = gpio_irq_level_mask, + .mask_ack = gpio_irq_level_mask, + .unmask = gpio_irq_level_unmask, + .set_type = gpio_irq_set_type, +}; + +void orion_gpio_irq_handler(int pinoff) +{ + u32 cause; + int pin; + + cause = readl(GPIO_DATA_IN(pinoff)) & readl(GPIO_LEVEL_MASK(pinoff)); + cause |= readl(GPIO_EDGE_CAUSE(pinoff)) & readl(GPIO_EDGE_MASK(pinoff)); + + for (pin = pinoff; pin < pinoff + 8; pin++) { + int irq = gpio_to_irq(pin); + struct irq_desc *desc = irq_desc + irq; + + if (!(cause & (1 << (pin & 31)))) + continue; + + if ((desc->status & IRQ_TYPE_SENSE_MASK) == IRQ_TYPE_EDGE_BOTH) { + /* Swap polarity (race with GPIO line) */ + u32 polarity; + + polarity = readl(GPIO_IN_POL(pin)); + polarity ^= 1 << (pin & 31); + writel(polarity, GPIO_IN_POL(pin)); + } + desc_handle_irq(irq, desc); + } +} diff --git a/arch/arm/plat-orion/include/plat/gpio.h b/arch/arm/plat-orion/include/plat/gpio.h new file mode 100644 index 000000000000..54deaf274b52 --- /dev/null +++ b/arch/arm/plat-orion/include/plat/gpio.h @@ -0,0 +1,39 @@ +/* + * arch/arm/plat-orion/include/plat/gpio.h + * + * 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. + */ + +#ifndef __PLAT_GPIO_H +#define __PLAT_GPIO_H + +/* + * GENERIC_GPIO primitives. + */ +int gpio_request(unsigned pin, const char *label); +void gpio_free(unsigned pin); +int gpio_direction_input(unsigned pin); +int gpio_direction_output(unsigned pin, int value); +int gpio_get_value(unsigned pin); +void gpio_set_value(unsigned pin, int value); + +/* + * Orion-specific GPIO API extensions. + */ +void orion_gpio_set_unused(unsigned pin); +void orion_gpio_set_valid(unsigned pin, int valid); +void orion_gpio_set_blink(unsigned pin, int blink); + +/* + * GPIO interrupt handling. + */ +extern struct irq_chip orion_gpio_irq_edge_chip; +extern struct irq_chip orion_gpio_irq_level_chip; +void orion_gpio_irq_handler(int irqoff); + + +#endif |
