diff options
Diffstat (limited to 'arch/arm/mach-orion5x/irq.c')
-rw-r--r-- | arch/arm/mach-orion5x/irq.c | 211 |
1 files changed, 211 insertions, 0 deletions
diff --git a/arch/arm/mach-orion5x/irq.c b/arch/arm/mach-orion5x/irq.c new file mode 100644 index 0000000..dd21f38 --- /dev/null +++ b/arch/arm/mach-orion5x/irq.c @@ -0,0 +1,211 @@ +/* + * arch/arm/mach-orion5x/irq.c + * + * Core IRQ functions for Marvell Orion System On Chip + * + * Maintainer: Tzachi Perelstein <tzachi@marvell.com> + * + * 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 <asm/gpio.h> +#include <asm/io.h> +#include <asm/arch/orion5x.h> +#include <asm/plat-orion/irq.h> +#include "common.h" + +/***************************************************************************** + * Orion GPIO IRQ + * + * GPIO_IN_POL register controlls 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 orion5x_gpio_irq_ack(u32 irq) +{ + int pin = irq_to_gpio(irq); + if (irq_desc[irq].status & IRQ_LEVEL) + /* + * Mask bit for level interrupt + */ + orion5x_clrbits(GPIO_LEVEL_MASK, 1 << pin); + else + /* + * Clear casue bit for egde interrupt + */ + orion5x_clrbits(GPIO_EDGE_CAUSE, 1 << pin); +} + +static void orion5x_gpio_irq_mask(u32 irq) +{ + int pin = irq_to_gpio(irq); + if (irq_desc[irq].status & IRQ_LEVEL) + orion5x_clrbits(GPIO_LEVEL_MASK, 1 << pin); + else + orion5x_clrbits(GPIO_EDGE_MASK, 1 << pin); +} + +static void orion5x_gpio_irq_unmask(u32 irq) +{ + int pin = irq_to_gpio(irq); + if (irq_desc[irq].status & IRQ_LEVEL) + orion5x_setbits(GPIO_LEVEL_MASK, 1 << pin); + else + orion5x_setbits(GPIO_EDGE_MASK, 1 << pin); +} + +static int orion5x_gpio_set_irq_type(u32 irq, u32 type) +{ + int pin = irq_to_gpio(irq); + struct irq_desc *desc; + + if ((orion5x_read(GPIO_IO_CONF) & (1 << pin)) == 0) { + printk(KERN_ERR "orion5x_gpio_set_irq_type failed " + "(irq %d, pin %d).\n", irq, pin); + return -EINVAL; + } + + desc = irq_desc + irq; + + switch (type) { + case IRQT_HIGH: + desc->handle_irq = handle_level_irq; + desc->status |= IRQ_LEVEL; + orion5x_clrbits(GPIO_IN_POL, (1 << pin)); + break; + case IRQT_LOW: + desc->handle_irq = handle_level_irq; + desc->status |= IRQ_LEVEL; + orion5x_setbits(GPIO_IN_POL, (1 << pin)); + break; + case IRQT_RISING: + desc->handle_irq = handle_edge_irq; + desc->status &= ~IRQ_LEVEL; + orion5x_clrbits(GPIO_IN_POL, (1 << pin)); + break; + case IRQT_FALLING: + desc->handle_irq = handle_edge_irq; + desc->status &= ~IRQ_LEVEL; + orion5x_setbits(GPIO_IN_POL, (1 << pin)); + break; + case IRQT_BOTHEDGE: + desc->handle_irq = handle_edge_irq; + desc->status &= ~IRQ_LEVEL; + /* + * set initial polarity based on current input level + */ + if ((orion5x_read(GPIO_IN_POL) ^ orion5x_read(GPIO_DATA_IN)) + & (1 << pin)) + orion5x_setbits(GPIO_IN_POL, (1 << pin)); /* falling */ + else + orion5x_clrbits(GPIO_IN_POL, (1 << pin)); /* rising */ + + break; + default: + printk(KERN_ERR "failed to set irq=%d (type=%d)\n", irq, type); + return -EINVAL; + } + + desc->status &= ~IRQ_TYPE_SENSE_MASK; + desc->status |= type & IRQ_TYPE_SENSE_MASK; + + return 0; +} + +static struct irq_chip orion5x_gpio_irq_chip = { + .name = "Orion-IRQ-GPIO", + .ack = orion5x_gpio_irq_ack, + .mask = orion5x_gpio_irq_mask, + .unmask = orion5x_gpio_irq_unmask, + .set_type = orion5x_gpio_set_irq_type, +}; + +static void orion5x_gpio_irq_handler(unsigned int irq, struct irq_desc *desc) +{ + u32 cause, offs, pin; + + BUG_ON(irq < IRQ_ORION5X_GPIO_0_7 || irq > IRQ_ORION5X_GPIO_24_31); + offs = (irq - IRQ_ORION5X_GPIO_0_7) * 8; + cause = (orion5x_read(GPIO_DATA_IN) & orion5x_read(GPIO_LEVEL_MASK)) | + (orion5x_read(GPIO_EDGE_CAUSE) & orion5x_read(GPIO_EDGE_MASK)); + + for (pin = offs; pin < offs + 8; pin++) { + if (cause & (1 << pin)) { + irq = gpio_to_irq(pin); + desc = irq_desc + irq; + if ((desc->status & IRQ_TYPE_SENSE_MASK) == IRQT_BOTHEDGE) { + /* Swap polarity (race with GPIO line) */ + u32 polarity = orion5x_read(GPIO_IN_POL); + polarity ^= 1 << pin; + orion5x_write(GPIO_IN_POL, polarity); + } + desc_handle_irq(irq, desc); + } + } +} + +static void __init orion5x_init_gpio_irq(void) +{ + int i; + struct irq_desc *desc; + + /* + * Mask and clear GPIO IRQ interrupts + */ + orion5x_write(GPIO_LEVEL_MASK, 0x0); + orion5x_write(GPIO_EDGE_MASK, 0x0); + orion5x_write(GPIO_EDGE_CAUSE, 0x0); + + /* + * Register chained level handlers for GPIO IRQs by default. + * User can use set_type() if he wants to use edge types handlers. + */ + for (i = IRQ_ORION5X_GPIO_START; i < NR_IRQS; i++) { + set_irq_chip(i, &orion5x_gpio_irq_chip); + set_irq_handler(i, handle_level_irq); + desc = irq_desc + i; + desc->status |= IRQ_LEVEL; + set_irq_flags(i, IRQF_VALID); + } + set_irq_chained_handler(IRQ_ORION5X_GPIO_0_7, orion5x_gpio_irq_handler); + set_irq_chained_handler(IRQ_ORION5X_GPIO_8_15, orion5x_gpio_irq_handler); + set_irq_chained_handler(IRQ_ORION5X_GPIO_16_23, orion5x_gpio_irq_handler); + set_irq_chained_handler(IRQ_ORION5X_GPIO_24_31, orion5x_gpio_irq_handler); +} + +/***************************************************************************** + * Orion Main IRQ + ****************************************************************************/ +static void __init orion5x_init_main_irq(void) +{ + orion_irq_init(0, (void __iomem *)MAIN_IRQ_MASK); +} + +void __init orion5x_init_irq(void) +{ + orion5x_init_main_irq(); + orion5x_init_gpio_irq(); +} |