drivers/irqchip/irq-sun4i.c

   1 /*
   2  * Allwinner A1X SoCs IRQ chip driver.
   3  *
   4  * Copyright (C) 2012 Maxime Ripard
   5  *
   6  * Maxime Ripard <maxime.ripard@free-electrons.com>
   7  *
   8  * Based on code from
   9  * Allwinner Technology Co., Ltd. <www.allwinnertech.com>
  10  * Benn Huang <benn@allwinnertech.com>
  11  *
  12  * This file is licensed under the terms of the GNU General Public
  13  * License version 2.  This program is licensed "as is" without any
  14  * warranty of any kind, whether express or implied.
  15  */
  16
  17 #include <linux/io.h>
  18 #include <linux/irq.h>
  19 #include <linux/of.h>
  20 #include <linux/of_address.h>
  21 #include <linux/of_irq.h>
  22
  23 #include <asm/exception.h>
  24 #include <asm/mach/irq.h>
  25
  26 #include "irqchip.h"
  27
  28 #define SUN4I_IRQ_VECTOR_REG            0x00
  29 #define SUN4I_IRQ_PROTECTION_REG        0x08
  30 #define SUN4I_IRQ_NMI_CTRL_REG          0x0c
  31 #define SUN4I_IRQ_PENDING_REG(x)        (0x10 + 0x4 * x)
  32 #define SUN4I_IRQ_FIQ_PENDING_REG(x)    (0x20 + 0x4 * x)
  33 #define SUN4I_IRQ_ENABLE_REG(x)         (0x40 + 0x4 * x)
  34 #define SUN4I_IRQ_MASK_REG(x)           (0x50 + 0x4 * x)
  35
  36 static void __iomem *sun4i_irq_base;
  37 static struct irq_domain *sun4i_irq_domain;
  38
  39 static asmlinkage void __exception_irq_entry sun4i_handle_irq(struct pt_regs *regs);
  40
  41 static void sun4i_irq_ack(struct irq_data *irqd)
  42 {
  43         unsigned int irq = irqd_to_hwirq(irqd);
  44         unsigned int irq_off = irq % 32;
  45         int reg = irq / 32;
  46         u32 val;
  47
  48         val = readl(sun4i_irq_base + SUN4I_IRQ_PENDING_REG(reg));
  49         writel(val | (1 << irq_off),
  50                sun4i_irq_base + SUN4I_IRQ_PENDING_REG(reg));
  51 }
  52
  53 static void sun4i_irq_mask(struct irq_data *irqd)
  54 {
  55         unsigned int irq = irqd_to_hwirq(irqd);
  56         unsigned int irq_off = irq % 32;
  57         int reg = irq / 32;
  58         u32 val;
  59
  60         val = readl(sun4i_irq_base + SUN4I_IRQ_ENABLE_REG(reg));
  61         writel(val & ~(1 << irq_off),
  62                sun4i_irq_base + SUN4I_IRQ_ENABLE_REG(reg));
  63 }
  64
  65 static void sun4i_irq_unmask(struct irq_data *irqd)
  66 {
  67         unsigned int irq = irqd_to_hwirq(irqd);
  68         unsigned int irq_off = irq % 32;
  69         int reg = irq / 32;
  70         u32 val;
  71
  72         val = readl(sun4i_irq_base + SUN4I_IRQ_ENABLE_REG(reg));
  73         writel(val | (1 << irq_off),
  74                sun4i_irq_base + SUN4I_IRQ_ENABLE_REG(reg));
  75 }
  76
  77 static struct irq_chip sun4i_irq_chip = {
  78         .name           = "sun4i_irq",
  79         .irq_ack        = sun4i_irq_ack,
  80         .irq_mask       = sun4i_irq_mask,
  81         .irq_unmask     = sun4i_irq_unmask,
  82 };
  83
  84 static int sun4i_irq_map(struct irq_domain *d, unsigned int virq,
  85                          irq_hw_number_t hw)
  86 {
  87         irq_set_chip_and_handler(virq, &sun4i_irq_chip,
  88                                  handle_level_irq);
  89         set_irq_flags(virq, IRQF_VALID | IRQF_PROBE);
  90
  91         return 0;
  92 }
  93
  94 static struct irq_domain_ops sun4i_irq_ops = {
  95         .map = sun4i_irq_map,
  96         .xlate = irq_domain_xlate_onecell,
  97 };
  98
  99 static int __init sun4i_of_init(struct device_node *node,
 100                                 struct device_node *parent)
 101 {
 102         sun4i_irq_base = of_iomap(node, 0);
 103         if (!sun4i_irq_base)
 104                 panic("%s: unable to map IC registers\n",
 105                         node->full_name);
 106
 107         /* Disable all interrupts */
 108         writel(0, sun4i_irq_base + SUN4I_IRQ_ENABLE_REG(0));
 109         writel(0, sun4i_irq_base + SUN4I_IRQ_ENABLE_REG(1));
 110         writel(0, sun4i_irq_base + SUN4I_IRQ_ENABLE_REG(2));
 111
 112         /* Mask all the interrupts */
 113         writel(0, sun4i_irq_base + SUN4I_IRQ_MASK_REG(0));
 114         writel(0, sun4i_irq_base + SUN4I_IRQ_MASK_REG(1));
 115         writel(0, sun4i_irq_base + SUN4I_IRQ_MASK_REG(2));
 116
 117         /* Clear all the pending interrupts */
 118         writel(0xffffffff, sun4i_irq_base + SUN4I_IRQ_PENDING_REG(0));
 119         writel(0xffffffff, sun4i_irq_base + SUN4I_IRQ_PENDING_REG(1));
 120         writel(0xffffffff, sun4i_irq_base + SUN4I_IRQ_PENDING_REG(2));
 121
 122         /* Enable protection mode */
 123         writel(0x01, sun4i_irq_base + SUN4I_IRQ_PROTECTION_REG);
 124
 125         /* Configure the external interrupt source type */
 126         writel(0x00, sun4i_irq_base + SUN4I_IRQ_NMI_CTRL_REG);
 127
 128         sun4i_irq_domain = irq_domain_add_linear(node, 3 * 32,
 129                                                  &sun4i_irq_ops, NULL);
 130         if (!sun4i_irq_domain)
 131                 panic("%s: unable to create IRQ domain\n", node->full_name);
 132
 133         set_handle_irq(sun4i_handle_irq);
 134
 135         return 0;
 136 }
 137 IRQCHIP_DECLARE(allwinner_sun4i_ic, "allwinner,sun4i-ic", sun4i_of_init);
 138
 139 static asmlinkage void __exception_irq_entry sun4i_handle_irq(struct pt_regs *regs)
 140 {
 141         u32 irq, hwirq;
 142
 143         hwirq = readl(sun4i_irq_base + SUN4I_IRQ_VECTOR_REG) >> 2;
 144         while (hwirq != 0) {
 145                 irq = irq_find_mapping(sun4i_irq_domain, hwirq);
 146                 handle_IRQ(irq, regs);
 147                 hwirq = readl(sun4i_irq_base + SUN4I_IRQ_VECTOR_REG) >> 2;
 148         }
 149 }