159 lines
4.5 KiB
C
159 lines
4.5 KiB
C
/*
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* Allwinner A1X SoCs IRQ chip driver.
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*
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* Copyright (C) 2012 Maxime Ripard
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*
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* Maxime Ripard <maxime.ripard@free-electrons.com>
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*
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* Based on code from
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* Allwinner Technology Co., Ltd. <www.allwinnertech.com>
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* Benn Huang <benn@allwinnertech.com>
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*
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* This file is licensed under the terms of the GNU General Public
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* License version 2. This program is licensed "as is" without any
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* warranty of any kind, whether express or implied.
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*/
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#include <linux/io.h>
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#include <linux/irq.h>
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#include <linux/irqchip.h>
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#include <linux/of.h>
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#include <linux/of_address.h>
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#include <linux/of_irq.h>
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#include <asm/exception.h>
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#define SUN4I_IRQ_VECTOR_REG 0x00
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#define SUN4I_IRQ_PROTECTION_REG 0x08
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#define SUN4I_IRQ_NMI_CTRL_REG 0x0c
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#define SUN4I_IRQ_PENDING_REG(x) (0x10 + 0x4 * x)
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#define SUN4I_IRQ_FIQ_PENDING_REG(x) (0x20 + 0x4 * x)
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#define SUN4I_IRQ_ENABLE_REG(x) (0x40 + 0x4 * x)
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#define SUN4I_IRQ_MASK_REG(x) (0x50 + 0x4 * x)
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static void __iomem *sun4i_irq_base;
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static struct irq_domain *sun4i_irq_domain;
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static void __exception_irq_entry sun4i_handle_irq(struct pt_regs *regs);
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static void sun4i_irq_ack(struct irq_data *irqd)
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{
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unsigned int irq = irqd_to_hwirq(irqd);
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if (irq != 0)
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return; /* Only IRQ 0 / the ENMI needs to be acked */
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writel(BIT(0), sun4i_irq_base + SUN4I_IRQ_PENDING_REG(0));
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}
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static void sun4i_irq_mask(struct irq_data *irqd)
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{
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unsigned int irq = irqd_to_hwirq(irqd);
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unsigned int irq_off = irq % 32;
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int reg = irq / 32;
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u32 val;
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val = readl(sun4i_irq_base + SUN4I_IRQ_ENABLE_REG(reg));
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writel(val & ~(1 << irq_off),
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sun4i_irq_base + SUN4I_IRQ_ENABLE_REG(reg));
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}
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static void sun4i_irq_unmask(struct irq_data *irqd)
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{
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unsigned int irq = irqd_to_hwirq(irqd);
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unsigned int irq_off = irq % 32;
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int reg = irq / 32;
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u32 val;
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val = readl(sun4i_irq_base + SUN4I_IRQ_ENABLE_REG(reg));
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writel(val | (1 << irq_off),
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sun4i_irq_base + SUN4I_IRQ_ENABLE_REG(reg));
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}
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static struct irq_chip sun4i_irq_chip = {
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.name = "sun4i_irq",
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.irq_eoi = sun4i_irq_ack,
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.irq_mask = sun4i_irq_mask,
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.irq_unmask = sun4i_irq_unmask,
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.flags = IRQCHIP_EOI_THREADED | IRQCHIP_EOI_IF_HANDLED,
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};
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static int sun4i_irq_map(struct irq_domain *d, unsigned int virq,
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irq_hw_number_t hw)
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{
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irq_set_chip_and_handler(virq, &sun4i_irq_chip, handle_fasteoi_irq);
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irq_set_probe(virq);
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return 0;
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}
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static const struct irq_domain_ops sun4i_irq_ops = {
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.map = sun4i_irq_map,
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.xlate = irq_domain_xlate_onecell,
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};
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static int __init sun4i_of_init(struct device_node *node,
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struct device_node *parent)
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{
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sun4i_irq_base = of_iomap(node, 0);
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if (!sun4i_irq_base)
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panic("%pOF: unable to map IC registers\n",
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node);
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/* Disable all interrupts */
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writel(0, sun4i_irq_base + SUN4I_IRQ_ENABLE_REG(0));
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writel(0, sun4i_irq_base + SUN4I_IRQ_ENABLE_REG(1));
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writel(0, sun4i_irq_base + SUN4I_IRQ_ENABLE_REG(2));
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/* Unmask all the interrupts, ENABLE_REG(x) is used for masking */
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writel(0, sun4i_irq_base + SUN4I_IRQ_MASK_REG(0));
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writel(0, sun4i_irq_base + SUN4I_IRQ_MASK_REG(1));
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writel(0, sun4i_irq_base + SUN4I_IRQ_MASK_REG(2));
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/* Clear all the pending interrupts */
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writel(0xffffffff, sun4i_irq_base + SUN4I_IRQ_PENDING_REG(0));
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writel(0xffffffff, sun4i_irq_base + SUN4I_IRQ_PENDING_REG(1));
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writel(0xffffffff, sun4i_irq_base + SUN4I_IRQ_PENDING_REG(2));
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/* Enable protection mode */
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writel(0x01, sun4i_irq_base + SUN4I_IRQ_PROTECTION_REG);
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/* Configure the external interrupt source type */
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writel(0x00, sun4i_irq_base + SUN4I_IRQ_NMI_CTRL_REG);
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sun4i_irq_domain = irq_domain_add_linear(node, 3 * 32,
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&sun4i_irq_ops, NULL);
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if (!sun4i_irq_domain)
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panic("%pOF: unable to create IRQ domain\n", node);
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set_handle_irq(sun4i_handle_irq);
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return 0;
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}
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IRQCHIP_DECLARE(allwinner_sun4i_ic, "allwinner,sun4i-a10-ic", sun4i_of_init);
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static void __exception_irq_entry sun4i_handle_irq(struct pt_regs *regs)
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{
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u32 hwirq;
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/*
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* hwirq == 0 can mean one of 3 things:
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* 1) no more irqs pending
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* 2) irq 0 pending
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* 3) spurious irq
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* So if we immediately get a reading of 0, check the irq-pending reg
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* to differentiate between 2 and 3. We only do this once to avoid
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* the extra check in the common case of 1 hapening after having
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* read the vector-reg once.
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*/
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hwirq = readl(sun4i_irq_base + SUN4I_IRQ_VECTOR_REG) >> 2;
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if (hwirq == 0 &&
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!(readl(sun4i_irq_base + SUN4I_IRQ_PENDING_REG(0)) & BIT(0)))
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return;
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do {
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handle_domain_irq(sun4i_irq_domain, hwirq, regs);
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hwirq = readl(sun4i_irq_base + SUN4I_IRQ_VECTOR_REG) >> 2;
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} while (hwirq != 0);
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}
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