diff options
Diffstat (limited to 'drivers/irqchip/irq-sun4i.c')
| -rw-r--r-- | drivers/irqchip/irq-sun4i.c | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/drivers/irqchip/irq-sun4i.c b/drivers/irqchip/irq-sun4i.c new file mode 100644 index 000000000..64155b686 --- /dev/null +++ b/drivers/irqchip/irq-sun4i.c @@ -0,0 +1,160 @@ +/* + * Allwinner A1X SoCs IRQ chip driver. + * + * Copyright (C) 2012 Maxime Ripard + * + * Maxime Ripard <maxime.ripard@free-electrons.com> + * + * Based on code from + * Allwinner Technology Co., Ltd. <www.allwinnertech.com> + * Benn Huang <benn@allwinnertech.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/io.h> +#include <linux/irq.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/of_irq.h> + +#include <asm/exception.h> +#include <asm/mach/irq.h> + +#include "irqchip.h" + +#define SUN4I_IRQ_VECTOR_REG 0x00 +#define SUN4I_IRQ_PROTECTION_REG 0x08 +#define SUN4I_IRQ_NMI_CTRL_REG 0x0c +#define SUN4I_IRQ_PENDING_REG(x) (0x10 + 0x4 * x) +#define SUN4I_IRQ_FIQ_PENDING_REG(x) (0x20 + 0x4 * x) +#define SUN4I_IRQ_ENABLE_REG(x) (0x40 + 0x4 * x) +#define SUN4I_IRQ_MASK_REG(x) (0x50 + 0x4 * x) + +static void __iomem *sun4i_irq_base; +static struct irq_domain *sun4i_irq_domain; + +static void __exception_irq_entry sun4i_handle_irq(struct pt_regs *regs); + +static void sun4i_irq_ack(struct irq_data *irqd) +{ + unsigned int irq = irqd_to_hwirq(irqd); + + if (irq != 0) + return; /* Only IRQ 0 / the ENMI needs to be acked */ + + writel(BIT(0), sun4i_irq_base + SUN4I_IRQ_PENDING_REG(0)); +} + +static void sun4i_irq_mask(struct irq_data *irqd) +{ + unsigned int irq = irqd_to_hwirq(irqd); + unsigned int irq_off = irq % 32; + int reg = irq / 32; + u32 val; + + val = readl(sun4i_irq_base + SUN4I_IRQ_ENABLE_REG(reg)); + writel(val & ~(1 << irq_off), + sun4i_irq_base + SUN4I_IRQ_ENABLE_REG(reg)); +} + +static void sun4i_irq_unmask(struct irq_data *irqd) +{ + unsigned int irq = irqd_to_hwirq(irqd); + unsigned int irq_off = irq % 32; + int reg = irq / 32; + u32 val; + + val = readl(sun4i_irq_base + SUN4I_IRQ_ENABLE_REG(reg)); + writel(val | (1 << irq_off), + sun4i_irq_base + SUN4I_IRQ_ENABLE_REG(reg)); +} + +static struct irq_chip sun4i_irq_chip = { + .name = "sun4i_irq", + .irq_eoi = sun4i_irq_ack, + .irq_mask = sun4i_irq_mask, + .irq_unmask = sun4i_irq_unmask, + .flags = IRQCHIP_EOI_THREADED | IRQCHIP_EOI_IF_HANDLED, +}; + +static int sun4i_irq_map(struct irq_domain *d, unsigned int virq, + irq_hw_number_t hw) +{ + irq_set_chip_and_handler(virq, &sun4i_irq_chip, handle_fasteoi_irq); + set_irq_flags(virq, IRQF_VALID | IRQF_PROBE); + + return 0; +} + +static struct irq_domain_ops sun4i_irq_ops = { + .map = sun4i_irq_map, + .xlate = irq_domain_xlate_onecell, +}; + +static int __init sun4i_of_init(struct device_node *node, + struct device_node *parent) +{ + sun4i_irq_base = of_iomap(node, 0); + if (!sun4i_irq_base) + panic("%s: unable to map IC registers\n", + node->full_name); + + /* Disable all interrupts */ + writel(0, sun4i_irq_base + SUN4I_IRQ_ENABLE_REG(0)); + writel(0, sun4i_irq_base + SUN4I_IRQ_ENABLE_REG(1)); + writel(0, sun4i_irq_base + SUN4I_IRQ_ENABLE_REG(2)); + + /* Unmask all the interrupts, ENABLE_REG(x) is used for masking */ + writel(0, sun4i_irq_base + SUN4I_IRQ_MASK_REG(0)); + writel(0, sun4i_irq_base + SUN4I_IRQ_MASK_REG(1)); + writel(0, sun4i_irq_base + SUN4I_IRQ_MASK_REG(2)); + + /* Clear all the pending interrupts */ + writel(0xffffffff, sun4i_irq_base + SUN4I_IRQ_PENDING_REG(0)); + writel(0xffffffff, sun4i_irq_base + SUN4I_IRQ_PENDING_REG(1)); + writel(0xffffffff, sun4i_irq_base + SUN4I_IRQ_PENDING_REG(2)); + + /* Enable protection mode */ + writel(0x01, sun4i_irq_base + SUN4I_IRQ_PROTECTION_REG); + + /* Configure the external interrupt source type */ + writel(0x00, sun4i_irq_base + SUN4I_IRQ_NMI_CTRL_REG); + + sun4i_irq_domain = irq_domain_add_linear(node, 3 * 32, + &sun4i_irq_ops, NULL); + if (!sun4i_irq_domain) + panic("%s: unable to create IRQ domain\n", node->full_name); + + set_handle_irq(sun4i_handle_irq); + + return 0; +} +IRQCHIP_DECLARE(allwinner_sun4i_ic, "allwinner,sun4i-a10-ic", sun4i_of_init); + +static void __exception_irq_entry sun4i_handle_irq(struct pt_regs *regs) +{ + u32 hwirq; + + /* + * hwirq == 0 can mean one of 3 things: + * 1) no more irqs pending + * 2) irq 0 pending + * 3) spurious irq + * So if we immediately get a reading of 0, check the irq-pending reg + * to differentiate between 2 and 3. We only do this once to avoid + * the extra check in the common case of 1 hapening after having + * read the vector-reg once. + */ + hwirq = readl(sun4i_irq_base + SUN4I_IRQ_VECTOR_REG) >> 2; + if (hwirq == 0 && + !(readl(sun4i_irq_base + SUN4I_IRQ_PENDING_REG(0)) & BIT(0))) + return; + + do { + handle_domain_irq(sun4i_irq_domain, hwirq, regs); + hwirq = readl(sun4i_irq_base + SUN4I_IRQ_VECTOR_REG) >> 2; + } while (hwirq != 0); +} |