linux/drivers/irqchip/irq-vt8500.c
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   1/*
   2 *  arch/arm/mach-vt8500/irq.c
   3 *
   4 *  Copyright (C) 2012 Tony Prisk <linux@prisktech.co.nz>
   5 *  Copyright (C) 2010 Alexey Charkov <alchark@gmail.com>
   6 *
   7 * This program is free software; you can redistribute it and/or modify
   8 * it under the terms of the GNU General Public License as published by
   9 * the Free Software Foundation; either version 2 of the License, or
  10 * (at your option) any later version.
  11 *
  12 * This program is distributed in the hope that it will be useful,
  13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 * GNU General Public License for more details.
  16 *
  17 * You should have received a copy of the GNU General Public License
  18 * along with this program; if not, write to the Free Software
  19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20 */
  21
  22/*
  23 * This file is copied and modified from the original irq.c provided by
  24 * Alexey Charkov. Minor changes have been made for Device Tree Support.
  25 */
  26
  27#include <linux/slab.h>
  28#include <linux/io.h>
  29#include <linux/irq.h>
  30#include <linux/irqdomain.h>
  31#include <linux/interrupt.h>
  32#include <linux/bitops.h>
  33
  34#include <linux/of.h>
  35#include <linux/of_irq.h>
  36#include <linux/of_address.h>
  37
  38#include <asm/irq.h>
  39#include <asm/exception.h>
  40#include <asm/mach/irq.h>
  41
  42#include "irqchip.h"
  43
  44#define VT8500_ICPC_IRQ         0x20
  45#define VT8500_ICPC_FIQ         0x24
  46#define VT8500_ICDC             0x40            /* Destination Control 64*u32 */
  47#define VT8500_ICIS             0x80            /* Interrupt status, 16*u32 */
  48
  49/* ICPC */
  50#define ICPC_MASK               0x3F
  51#define ICPC_ROTATE             BIT(6)
  52
  53/* IC_DCTR */
  54#define ICDC_IRQ                0x00
  55#define ICDC_FIQ                0x01
  56#define ICDC_DSS0               0x02
  57#define ICDC_DSS1               0x03
  58#define ICDC_DSS2               0x04
  59#define ICDC_DSS3               0x05
  60#define ICDC_DSS4               0x06
  61#define ICDC_DSS5               0x07
  62
  63#define VT8500_INT_DISABLE      0
  64#define VT8500_INT_ENABLE       BIT(3)
  65
  66#define VT8500_TRIGGER_HIGH     0
  67#define VT8500_TRIGGER_RISING   BIT(5)
  68#define VT8500_TRIGGER_FALLING  BIT(6)
  69#define VT8500_EDGE             ( VT8500_TRIGGER_RISING \
  70                                | VT8500_TRIGGER_FALLING)
  71
  72/* vt8500 has 1 intc, wm8505 and wm8650 have 2 */
  73#define VT8500_INTC_MAX         2
  74
  75struct vt8500_irq_data {
  76        void __iomem            *base;          /* IO Memory base address */
  77        struct irq_domain       *domain;        /* Domain for this controller */
  78};
  79
  80/* Global variable for accessing io-mem addresses */
  81static struct vt8500_irq_data intc[VT8500_INTC_MAX];
  82static u32 active_cnt = 0;
  83
  84static void vt8500_irq_mask(struct irq_data *d)
  85{
  86        struct vt8500_irq_data *priv = d->domain->host_data;
  87        void __iomem *base = priv->base;
  88        void __iomem *stat_reg = base + VT8500_ICIS + (d->hwirq < 32 ? 0 : 4);
  89        u8 edge, dctr;
  90        u32 status;
  91
  92        edge = readb(base + VT8500_ICDC + d->hwirq) & VT8500_EDGE;
  93        if (edge) {
  94                status = readl(stat_reg);
  95
  96                status |= (1 << (d->hwirq & 0x1f));
  97                writel(status, stat_reg);
  98        } else {
  99                dctr = readb(base + VT8500_ICDC + d->hwirq);
 100                dctr &= ~VT8500_INT_ENABLE;
 101                writeb(dctr, base + VT8500_ICDC + d->hwirq);
 102        }
 103}
 104
 105static void vt8500_irq_unmask(struct irq_data *d)
 106{
 107        struct vt8500_irq_data *priv = d->domain->host_data;
 108        void __iomem *base = priv->base;
 109        u8 dctr;
 110
 111        dctr = readb(base + VT8500_ICDC + d->hwirq);
 112        dctr |= VT8500_INT_ENABLE;
 113        writeb(dctr, base + VT8500_ICDC + d->hwirq);
 114}
 115
 116static int vt8500_irq_set_type(struct irq_data *d, unsigned int flow_type)
 117{
 118        struct vt8500_irq_data *priv = d->domain->host_data;
 119        void __iomem *base = priv->base;
 120        u8 dctr;
 121
 122        dctr = readb(base + VT8500_ICDC + d->hwirq);
 123        dctr &= ~VT8500_EDGE;
 124
 125        switch (flow_type) {
 126        case IRQF_TRIGGER_LOW:
 127                return -EINVAL;
 128        case IRQF_TRIGGER_HIGH:
 129                dctr |= VT8500_TRIGGER_HIGH;
 130                __irq_set_handler_locked(d->irq, handle_level_irq);
 131                break;
 132        case IRQF_TRIGGER_FALLING:
 133                dctr |= VT8500_TRIGGER_FALLING;
 134                __irq_set_handler_locked(d->irq, handle_edge_irq);
 135                break;
 136        case IRQF_TRIGGER_RISING:
 137                dctr |= VT8500_TRIGGER_RISING;
 138                __irq_set_handler_locked(d->irq, handle_edge_irq);
 139                break;
 140        }
 141        writeb(dctr, base + VT8500_ICDC + d->hwirq);
 142
 143        return 0;
 144}
 145
 146static struct irq_chip vt8500_irq_chip = {
 147        .name = "vt8500",
 148        .irq_ack = vt8500_irq_mask,
 149        .irq_mask = vt8500_irq_mask,
 150        .irq_unmask = vt8500_irq_unmask,
 151        .irq_set_type = vt8500_irq_set_type,
 152};
 153
 154static void __init vt8500_init_irq_hw(void __iomem *base)
 155{
 156        u32 i;
 157
 158        /* Enable rotating priority for IRQ */
 159        writel(ICPC_ROTATE, base + VT8500_ICPC_IRQ);
 160        writel(0x00, base + VT8500_ICPC_FIQ);
 161
 162        /* Disable all interrupts and route them to IRQ */
 163        for (i = 0; i < 64; i++)
 164                writeb(VT8500_INT_DISABLE | ICDC_IRQ, base + VT8500_ICDC + i);
 165}
 166
 167static int vt8500_irq_map(struct irq_domain *h, unsigned int virq,
 168                                                        irq_hw_number_t hw)
 169{
 170        irq_set_chip_and_handler(virq, &vt8500_irq_chip, handle_level_irq);
 171        set_irq_flags(virq, IRQF_VALID);
 172
 173        return 0;
 174}
 175
 176static struct irq_domain_ops vt8500_irq_domain_ops = {
 177        .map = vt8500_irq_map,
 178        .xlate = irq_domain_xlate_onecell,
 179};
 180
 181asmlinkage void __exception_irq_entry vt8500_handle_irq(struct pt_regs *regs)
 182{
 183        u32 stat, i;
 184        int irqnr, virq;
 185        void __iomem *base;
 186
 187        /* Loop through each active controller */
 188        for (i=0; i<active_cnt; i++) {
 189                base = intc[i].base;
 190                irqnr = readl_relaxed(base) & 0x3F;
 191                /*
 192                  Highest Priority register default = 63, so check that this
 193                  is a real interrupt by checking the status register
 194                */
 195                if (irqnr == 63) {
 196                        stat = readl_relaxed(base + VT8500_ICIS + 4);
 197                        if (!(stat & BIT(31)))
 198                                continue;
 199                }
 200
 201                virq = irq_find_mapping(intc[i].domain, irqnr);
 202                handle_IRQ(virq, regs);
 203        }
 204}
 205
 206int __init vt8500_irq_init(struct device_node *node, struct device_node *parent)
 207{
 208        int irq, i;
 209        struct device_node *np = node;
 210
 211        if (active_cnt == VT8500_INTC_MAX) {
 212                pr_err("%s: Interrupt controllers > VT8500_INTC_MAX\n",
 213                                                                __func__);
 214                goto out;
 215        }
 216
 217        intc[active_cnt].base = of_iomap(np, 0);
 218        intc[active_cnt].domain = irq_domain_add_linear(node, 64,
 219                        &vt8500_irq_domain_ops, &intc[active_cnt]);
 220
 221        if (!intc[active_cnt].base) {
 222                pr_err("%s: Unable to map IO memory\n", __func__);
 223                goto out;
 224        }
 225
 226        if (!intc[active_cnt].domain) {
 227                pr_err("%s: Unable to add irq domain!\n", __func__);
 228                goto out;
 229        }
 230
 231        set_handle_irq(vt8500_handle_irq);
 232
 233        vt8500_init_irq_hw(intc[active_cnt].base);
 234
 235        pr_info("vt8500-irq: Added interrupt controller\n");
 236
 237        active_cnt++;
 238
 239        /* check if this is a slaved controller */
 240        if (of_irq_count(np) != 0) {
 241                /* check that we have the correct number of interrupts */
 242                if (of_irq_count(np) != 8) {
 243                        pr_err("%s: Incorrect IRQ map for slaved controller\n",
 244                                        __func__);
 245                        return -EINVAL;
 246                }
 247
 248                for (i = 0; i < 8; i++) {
 249                        irq = irq_of_parse_and_map(np, i);
 250                        enable_irq(irq);
 251                }
 252
 253                pr_info("vt8500-irq: Enabled slave->parent interrupts\n");
 254        }
 255out:
 256        return 0;
 257}
 258
 259IRQCHIP_DECLARE(vt8500_irq, "via,vt8500-intc", vt8500_irq_init);
 260
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