drivers/irqchip/irq-vt8500.c

   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
  61 struct 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 */
  67 static struct vt8500_irq_data intc[VT8500_INTC_MAX];
  68 static u32 active_cnt = 0;
  69
  70 static 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
  91 static 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
 102 static 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
 132 static 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
 140 static 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
 153 static 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
 161 static const struct irq_domain_ops vt8500_irq_domain_ops = {
 162         .map = vt8500_irq_map,
 163         .xlate = irq_domain_xlate_onecell,
 164 };
 165
 166 static 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                 generic_handle_domain_irq(intc[i].domain, irqnr);
 187         }
 188 }
 189
 190 static 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         }
 240 out:
 241         return 0;
 242 }
 243
 244 IRQCHIP_DECLARE(vt8500_irq, "via,vt8500-intc", vt8500_irq_init);