From f00666140cb84cd80276c9a874198874890d5733 Mon Sep 17 00:00:00 2001 From: Tzachi Perelstein Date: Thu, 15 Nov 2007 10:57:48 +0200 Subject: [PATCH] [ARM] Orion edge GPIO IRQ support This patch adds support for Orion edge sensitive GPIO IRQs. Signed-off-by: Tzachi Perelstein Signed-off-by: Nicolas Pitre CC: Thomas Gleixner --- arch/arm/mach-orion/gpio.c | 2 +- arch/arm/mach-orion/irq.c | 117 +++++++++++++++++++++++++++++++------ 2 files changed, 100 insertions(+), 19 deletions(-) diff --git a/arch/arm/mach-orion/gpio.c b/arch/arm/mach-orion/gpio.c index 0418f5b1ebe7..d5f00c86d616 100644 --- a/arch/arm/mach-orion/gpio.c +++ b/arch/arm/mach-orion/gpio.c @@ -93,7 +93,7 @@ int gpio_get_value(unsigned pin) int val, mask = 1 << pin; if (orion_read(GPIO_IO_CONF) & mask) - val = orion_read(GPIO_DATA_IN); + val = orion_read(GPIO_DATA_IN) ^ orion_read(GPIO_IN_POL); else val = orion_read(GPIO_OUT); diff --git a/arch/arm/mach-orion/irq.c b/arch/arm/mach-orion/irq.c index 585a0fb06262..df7e12ad378b 100644 --- a/arch/arm/mach-orion/irq.c +++ b/arch/arm/mach-orion/irq.c @@ -19,22 +19,66 @@ /***************************************************************************** * 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 orion_gpio_irq_ack(u32 irq) +{ + int pin = irq_to_gpio(irq); + if (irq_desc[irq].status & IRQ_LEVEL) + /* + * Mask bit for level interrupt + */ + orion_clrbits(GPIO_LEVEL_MASK, 1 << pin); + else + /* + * Clear casue bit for egde interrupt + */ + orion_clrbits(GPIO_EDGE_CAUSE, 1 << pin); +} + static void orion_gpio_irq_mask(u32 irq) { int pin = irq_to_gpio(irq); - orion_clrbits(GPIO_LEVEL_MASK, 1 << pin); + if (irq_desc[irq].status & IRQ_LEVEL) + orion_clrbits(GPIO_LEVEL_MASK, 1 << pin); + else + orion_clrbits(GPIO_EDGE_MASK, 1 << pin); } static void orion_gpio_irq_unmask(u32 irq) { int pin = irq_to_gpio(irq); - orion_setbits(GPIO_LEVEL_MASK, 1 << pin); + if (irq_desc[irq].status & IRQ_LEVEL) + orion_setbits(GPIO_LEVEL_MASK, 1 << pin); + else + orion_setbits(GPIO_EDGE_MASK, 1 << pin); } static int orion_gpio_set_irq_type(u32 irq, u32 type) { int pin = irq_to_gpio(irq); + struct irq_desc *desc; if ((orion_read(GPIO_IO_CONF) & (1 << pin)) == 0) { printk(KERN_ERR "orion_gpio_set_irq_type failed " @@ -42,24 +86,56 @@ static int orion_gpio_set_irq_type(u32 irq, u32 type) return -EINVAL; } + desc = irq_desc + irq; + switch (type) { case IRQT_HIGH: + desc->handle_irq = handle_level_irq; + desc->status |= IRQ_LEVEL; orion_clrbits(GPIO_IN_POL, (1 << pin)); break; case IRQT_LOW: + desc->handle_irq = handle_level_irq; + desc->status |= IRQ_LEVEL; orion_setbits(GPIO_IN_POL, (1 << pin)); + break; + case IRQT_RISING: + desc->handle_irq = handle_edge_irq; + desc->status &= ~IRQ_LEVEL; + orion_clrbits(GPIO_IN_POL, (1 << pin)); + break; + case IRQT_FALLING: + desc->handle_irq = handle_edge_irq; + desc->status &= ~IRQ_LEVEL; + orion_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 ((orion_read(GPIO_IN_POL) ^ orion_read(GPIO_DATA_IN)) + & (1 << pin)) + orion_setbits(GPIO_IN_POL, (1 << pin)); /* falling */ + else + orion_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 orion_gpio_irq_chip = { .name = "Orion-IRQ-GPIO", - .ack = orion_gpio_irq_mask, + .ack = orion_gpio_irq_ack, .mask = orion_gpio_irq_mask, .unmask = orion_gpio_irq_unmask, .set_type = orion_gpio_set_irq_type, @@ -67,24 +143,24 @@ static struct irq_chip orion_gpio_irq_chip = { static void orion_gpio_irq_handler(unsigned int irq, struct irq_desc *desc) { - int i; - u32 cause, shift; + u32 cause, offs, pin; BUG_ON(irq < IRQ_ORION_GPIO_0_7 || irq > IRQ_ORION_GPIO_24_31); - shift = (irq - IRQ_ORION_GPIO_0_7) * 8; - cause = orion_read(GPIO_EDGE_CAUSE) & orion_read(GPIO_LEVEL_MASK); - cause &= (0xff << shift); + offs = (irq - IRQ_ORION_GPIO_0_7) * 8; + cause = (orion_read(GPIO_DATA_IN) & orion_read(GPIO_LEVEL_MASK)) | + (orion_read(GPIO_EDGE_CAUSE) & orion_read(GPIO_EDGE_MASK)); - for (i = shift; i < shift + 8; i++) { - if (cause & (1 << i)) { - int gpio_irq = i + IRQ_ORION_GPIO_START; - if (gpio_irq > 0) { - desc = irq_desc + gpio_irq; - desc_handle_irq(gpio_irq, desc); - } else { - printk(KERN_ERR "orion_gpio_irq_handler error, " - "invalid irq %d\n", gpio_irq); + 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 = orion_read(GPIO_IN_POL); + polarity ^= 1 << pin; + orion_write(GPIO_IN_POL, polarity); } + desc_handle_irq(irq, desc); } } } @@ -92,19 +168,24 @@ static void orion_gpio_irq_handler(unsigned int irq, struct irq_desc *desc) static void __init orion_init_gpio_irq(void) { int i; + struct irq_desc *desc; /* * Mask and clear GPIO IRQ interrupts */ orion_write(GPIO_LEVEL_MASK, 0x0); + orion_write(GPIO_EDGE_MASK, 0x0); orion_write(GPIO_EDGE_CAUSE, 0x0); /* - * Register chained level handlers for GPIO IRQs + * 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_ORION_GPIO_START; i < NR_IRQS; i++) { set_irq_chip(i, &orion_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_ORION_GPIO_0_7, orion_gpio_irq_handler);