linux/drivers/irqchip/irq-vt8500.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 *  arch/arm/mach-vt8500/irq.c
   4 *
   5 *  Copyright (C) 2012 Tony Prisk <linux@prisktech.co.nz>
   6 *  Copyright (C) 2010 Alexey Charkov <alchark@gmail.com>
   7 */
   8
   9/*
  10 * This file is copied and modified from the original irq.c provided by
  11 * Alexey Charkov. Minor changes have been made for Device Tree Support.
  12 */
  13
  14#include <linux/slab.h>
  15#include <linux/io.h>
  16#include <linux/irq.h>
  17#include <linux/irqchip.h>
  18#include <linux/irqdomain.h>
  19#include <linux/interrupt.h>
  20#include <linux/bitops.h>
  21
  22#include <linux/of.h>
  23#include <linux/of_irq.h>
  24#include <linux/of_address.h>
  25
  26#include <asm/irq.h>
  27#include <asm/exception.h>
  28#include <asm/mach/irq.h>
  29
  30#define VT8500_ICPC_IRQ         0x20
  31#define VT8500_ICPC_FIQ         0x24
  32#define VT8500_ICDC             0x40            /* Destination Control 64*u32 */
  33#define VT8500_ICIS             0x80            /* Interrupt status, 16*u32 */
  34
  35/* ICPC */
  36#define ICPC_MASK               0x3F
  37#define ICPC_ROTATE             BIT(6)
  38
  39/* IC_DCTR */
  40#define ICDC_IRQ                0x00
  41#define ICDC_FIQ                0x01
  42#define ICDC_DSS0               0x02
  43#define ICDC_DSS1               0x03
  44#define ICDC_DSS2               0x04
  45#define ICDC_DSS3               0x05
  46#define ICDC_DSS4               0x06
  47#define ICDC_DSS5               0x07
  48
  49#define VT8500_INT_DISABLE      0
  50#define VT8500_INT_ENABLE       BIT(3)
  51
  52#define VT8500_TRIGGER_HIGH     0
  53#define VT8500_TRIGGER_RISING   BIT(5)
  54#define VT8500_TRIGGER_FALLING  BIT(6)
  55#define VT8500_EDGE             ( VT8500_TRIGGER_RISING \
  56                                | VT8500_TRIGGER_FALLING)
  57
  58/* vt8500 has 1 intc, wm8505 and wm8650 have 2 */
  59#define VT8500_INTC_MAX         2
  60
  61struct vt8500_irq_data {
  62        void __iomem            *base;          /* IO Memory base address */
  63        struct irq_domain       *domain;        /* Domain for this controller */
  64};
  65
  66/* Global variable for accessing io-mem addresses */
  67static struct vt8500_irq_data intc[VT8500_INTC_MAX];
  68static u32 active_cnt = 0;
  69
  70static void vt8500_irq_mask(struct irq_data *d)
  71{
  72        struct vt8500_irq_data *priv = d->domain->host_data;
  73        void __iomem *base = priv->base;
  74        void __iomem *stat_reg = base + VT8500_ICIS + (d->hwirq < 32 ? 0 : 4);
  75        u8 edge, dctr;
  76        u32 status;
  77
  78        edge = readb(base + VT8500_ICDC + d->hwirq) & VT8500_EDGE;
  79        if (edge) {
  80                status = readl(stat_reg);
  81
  82                status |= (1 << (d->hwirq & 0x1f));
  83                writel(status, stat_reg);
  84        } else {
  85                dctr = readb(base + VT8500_ICDC + d->hwirq);
  86                dctr &= ~VT8500_INT_ENABLE;
  87                writeb(dctr, base + VT8500_ICDC + d->hwirq);
  88        }
  89}
  90
  91static void vt8500_irq_unmask(struct irq_data *d)
  92{
  93        struct vt8500_irq_data *priv = d->domain->host_data;
  94        void __iomem *base = priv->base;
  95        u8 dctr;
  96
  97        dctr = readb(base + VT8500_ICDC + d->hwirq);
  98        dctr |= VT8500_INT_ENABLE;
  99        writeb(dctr, base + VT8500_ICDC + d->hwirq);
 100}
 101
 102static int vt8500_irq_set_type(struct irq_data *d, unsigned int flow_type)
 103{
 104        struct vt8500_irq_data *priv = d->domain->host_data;
 105        void __iomem *base = priv->base;
 106        u8 dctr;
 107
 108        dctr = readb(base + VT8500_ICDC + d->hwirq);
 109        dctr &= ~VT8500_EDGE;
 110
 111        switch (flow_type) {
 112        case IRQF_TRIGGER_LOW:
 113                return -EINVAL;
 114        case IRQF_TRIGGER_HIGH:
 115                dctr |= VT8500_TRIGGER_HIGH;
 116                irq_set_handler_locked(d, handle_level_irq);
 117                break;
 118        case IRQF_TRIGGER_FALLING:
 119                dctr |= VT8500_TRIGGER_FALLING;
 120                irq_set_handler_locked(d, handle_edge_irq);
 121                break;
 122        case IRQF_TRIGGER_RISING:
 123                dctr |= VT8500_TRIGGER_RISING;
 124                irq_set_handler_locked(d, handle_edge_irq);
 125                break;
 126        }
 127        writeb(dctr, base + VT8500_ICDC + d->hwirq);
 128
 129        return 0;
 130}
 131
 132static struct irq_chip vt8500_irq_chip = {
 133        .name = "vt8500",
 134        .irq_ack = vt8500_irq_mask,
 135        .irq_mask = vt8500_irq_mask,
 136        .irq_unmask = vt8500_irq_unmask,
 137        .irq_set_type = vt8500_irq_set_type,
 138};
 139
 140static void __init vt8500_init_irq_hw(void __iomem *base)
 141{
 142        u32 i;
 143
 144        /* Enable rotating priority for IRQ */
 145        writel(ICPC_ROTATE, base + VT8500_ICPC_IRQ);
 146        writel(0x00, base + VT8500_ICPC_FIQ);
 147
 148        /* Disable all interrupts and route them to IRQ */
 149        for (i = 0; i < 64; i++)
 150                writeb(VT8500_INT_DISABLE | ICDC_IRQ, base + VT8500_ICDC + i);
 151}
 152
 153static int vt8500_irq_map(struct irq_domain *h, unsigned int virq,
 154                                                        irq_hw_number_t hw)
 155{
 156        irq_set_chip_and_handler(virq, &vt8500_irq_chip, handle_level_irq);
 157
 158        return 0;
 159}
 160
 161static const struct irq_domain_ops vt8500_irq_domain_ops = {
 162        .map = vt8500_irq_map,
 163        .xlate = irq_domain_xlate_onecell,
 164};
 165
 166static void __exception_irq_entry vt8500_handle_irq(struct pt_regs *regs)
 167{
 168        u32 stat, i;
 169        int irqnr;
 170        void __iomem *base;
 171
 172        /* Loop through each active controller */
 173        for (i=0; i<active_cnt; i++) {
 174                base = intc[i].base;
 175                irqnr = readl_relaxed(base) & 0x3F;
 176                /*
 177                  Highest Priority register default = 63, so check that this
 178                  is a real interrupt by checking the status register
 179                */
 180                if (irqnr == 63) {
 181                        stat = readl_relaxed(base + VT8500_ICIS + 4);
 182                        if (!(stat & BIT(31)))
 183                                continue;
 184                }
 185
 186                handle_domain_irq(intc[i].domain, irqnr, regs);
 187        }
 188}
 189
 190static int __init vt8500_irq_init(struct device_node *node,
 191                                  struct device_node *parent)
 192{
 193        int irq, i;
 194        struct device_node *np = node;
 195
 196        if (active_cnt == VT8500_INTC_MAX) {
 197                pr_err("%s: Interrupt controllers > VT8500_INTC_MAX\n",
 198                                                                __func__);
 199                goto out;
 200        }
 201
 202        intc[active_cnt].base = of_iomap(np, 0);
 203        intc[active_cnt].domain = irq_domain_add_linear(node, 64,
 204                        &vt8500_irq_domain_ops, &intc[active_cnt]);
 205
 206        if (!intc[active_cnt].base) {
 207                pr_err("%s: Unable to map IO memory\n", __func__);
 208                goto out;
 209        }
 210
 211        if (!intc[active_cnt].domain) {
 212                pr_err("%s: Unable to add irq domain!\n", __func__);
 213                goto out;
 214        }
 215
 216        set_handle_irq(vt8500_handle_irq);
 217
 218        vt8500_init_irq_hw(intc[active_cnt].base);
 219
 220        pr_info("vt8500-irq: Added interrupt controller\n");
 221
 222        active_cnt++;
 223
 224        /* check if this is a slaved controller */
 225        if (of_irq_count(np) != 0) {
 226                /* check that we have the correct number of interrupts */
 227                if (of_irq_count(np) != 8) {
 228                        pr_err("%s: Incorrect IRQ map for slaved controller\n",
 229                                        __func__);
 230                        return -EINVAL;
 231                }
 232
 233                for (i = 0; i < 8; i++) {
 234                        irq = irq_of_parse_and_map(np, i);
 235                        enable_irq(irq);
 236                }
 237
 238                pr_info("vt8500-irq: Enabled slave->parent interrupts\n");
 239        }
 240out:
 241        return 0;
 242}
 243
 244IRQCHIP_DECLARE(vt8500_irq, "via,vt8500-intc", vt8500_irq_init);
 245