arch/arm/mach-vt8500/irq.c

   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
  41 #define VT8500_ICPC_IRQ         0x20
  42 #define VT8500_ICPC_FIQ         0x24
  43 #define VT8500_ICDC             0x40            /* Destination Control 64*u32 */
  44 #define VT8500_ICIS             0x80            /* Interrupt status, 16*u32 */
  45
  46 /* ICPC */
  47 #define ICPC_MASK               0x3F
  48 #define ICPC_ROTATE             BIT(6)
  49
  50 /* IC_DCTR */
  51 #define ICDC_IRQ                0x00
  52 #define ICDC_FIQ                0x01
  53 #define ICDC_DSS0               0x02
  54 #define ICDC_DSS1               0x03
  55 #define ICDC_DSS2               0x04
  56 #define ICDC_DSS3               0x05
  57 #define ICDC_DSS4               0x06
  58 #define ICDC_DSS5               0x07
  59
  60 #define VT8500_INT_DISABLE      0
  61 #define VT8500_INT_ENABLE       BIT(3)
  62
  63 #define VT8500_TRIGGER_HIGH     0
  64 #define VT8500_TRIGGER_RISING   BIT(5)
  65 #define VT8500_TRIGGER_FALLING  BIT(6)
  66 #define VT8500_EDGE             ( VT8500_TRIGGER_RISING \
  67                                 | VT8500_TRIGGER_FALLING)
  68
  69 /* vt8500 has 1 intc, wm8505 and wm8650 have 2 */
  70 #define VT8500_INTC_MAX         2
  71
  72 struct vt8500_irq_data {
  73         void __iomem            *base;          /* IO Memory base address */
  74         struct irq_domain       *domain;        /* Domain for this controller */
  75 };
  76
  77 /* Global variable for accessing io-mem addresses */
  78 static struct vt8500_irq_data intc[VT8500_INTC_MAX];
  79 static u32 active_cnt = 0;
  80
  81 static void vt8500_irq_mask(struct irq_data *d)
  82 {
  83         struct vt8500_irq_data *priv = d->domain->host_data;
  84         void __iomem *base = priv->base;
  85         void __iomem *stat_reg = base + VT8500_ICIS + (d->hwirq < 32 ? 0 : 4);
  86         u8 edge, dctr;
  87         u32 status;
  88
  89         edge = readb(base + VT8500_ICDC + d->hwirq) & VT8500_EDGE;
  90         if (edge) {
  91                 status = readl(stat_reg);
  92
  93                 status |= (1 << (d->hwirq & 0x1f));
  94                 writel(status, stat_reg);
  95         } else {
  96                 dctr = readb(base + VT8500_ICDC + d->hwirq);
  97                 dctr &= ~VT8500_INT_ENABLE;
  98                 writeb(dctr, base + VT8500_ICDC + d->hwirq);
  99         }
 100 }
 101
 102 static void vt8500_irq_unmask(struct irq_data *d)
 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_INT_ENABLE;
 110         writeb(dctr, base + VT8500_ICDC + d->hwirq);
 111 }
 112
 113 static int vt8500_irq_set_type(struct irq_data *d, unsigned int flow_type)
 114 {
 115         struct vt8500_irq_data *priv = d->domain->host_data;
 116         void __iomem *base = priv->base;
 117         u8 dctr;
 118
 119         dctr = readb(base + VT8500_ICDC + d->hwirq);
 120         dctr &= ~VT8500_EDGE;
 121
 122         switch (flow_type) {
 123         case IRQF_TRIGGER_LOW:
 124                 return -EINVAL;
 125         case IRQF_TRIGGER_HIGH:
 126                 dctr |= VT8500_TRIGGER_HIGH;
 127                 __irq_set_handler_locked(d->irq, handle_level_irq);
 128                 break;
 129         case IRQF_TRIGGER_FALLING:
 130                 dctr |= VT8500_TRIGGER_FALLING;
 131                 __irq_set_handler_locked(d->irq, handle_edge_irq);
 132                 break;
 133         case IRQF_TRIGGER_RISING:
 134                 dctr |= VT8500_TRIGGER_RISING;
 135                 __irq_set_handler_locked(d->irq, handle_edge_irq);
 136                 break;
 137         }
 138         writeb(dctr, base + VT8500_ICDC + d->hwirq);
 139
 140         return 0;
 141 }
 142
 143 static struct irq_chip vt8500_irq_chip = {
 144         .name = "vt8500",
 145         .irq_ack = vt8500_irq_mask,
 146         .irq_mask = vt8500_irq_mask,
 147         .irq_unmask = vt8500_irq_unmask,
 148         .irq_set_type = vt8500_irq_set_type,
 149 };
 150
 151 static void __init vt8500_init_irq_hw(void __iomem *base)
 152 {
 153         u32 i;
 154
 155         /* Enable rotating priority for IRQ */
 156         writel(ICPC_ROTATE, base + VT8500_ICPC_IRQ);
 157         writel(0x00, base + VT8500_ICPC_FIQ);
 158
 159         /* Disable all interrupts and route them to IRQ */
 160         for (i = 0; i < 64; i++)
 161                 writeb(VT8500_INT_DISABLE | ICDC_IRQ, base + VT8500_ICDC + i);
 162 }
 163
 164 static int vt8500_irq_map(struct irq_domain *h, unsigned int virq,
 165                                                         irq_hw_number_t hw)
 166 {
 167         irq_set_chip_and_handler(virq, &vt8500_irq_chip, handle_level_irq);
 168         set_irq_flags(virq, IRQF_VALID);
 169
 170         return 0;
 171 }
 172
 173 static struct irq_domain_ops vt8500_irq_domain_ops = {
 174         .map = vt8500_irq_map,
 175         .xlate = irq_domain_xlate_onecell,
 176 };
 177
 178 asmlinkage void __exception_irq_entry vt8500_handle_irq(struct pt_regs *regs)
 179 {
 180         u32 stat, i;
 181         int irqnr, virq;
 182         void __iomem *base;
 183
 184         /* Loop through each active controller */
 185         for (i=0; i<active_cnt; i++) {
 186                 base = intc[i].base;
 187                 irqnr = readl_relaxed(base) & 0x3F;
 188                 /*
 189                   Highest Priority register default = 63, so check that this
 190                   is a real interrupt by checking the status register
 191                 */
 192                 if (irqnr == 63) {
 193                         stat = readl_relaxed(base + VT8500_ICIS + 4);
 194                         if (!(stat & BIT(31)))
 195                                 continue;
 196                 }
 197
 198                 virq = irq_find_mapping(intc[i].domain, irqnr);
 199                 handle_IRQ(virq, regs);
 200         }
 201 }
 202
 203 int __init vt8500_irq_init(struct device_node *node, struct device_node *parent)
 204 {
 205         int irq, i;
 206         struct device_node *np = node;
 207
 208         if (active_cnt == VT8500_INTC_MAX) {
 209                 pr_err("%s: Interrupt controllers > VT8500_INTC_MAX\n",
 210                                                                 __func__);
 211                 goto out;
 212         }
 213
 214         intc[active_cnt].base = of_iomap(np, 0);
 215         intc[active_cnt].domain = irq_domain_add_linear(node, 64,
 216                         &vt8500_irq_domain_ops, &intc[active_cnt]);
 217
 218         if (!intc[active_cnt].base) {
 219                 pr_err("%s: Unable to map IO memory\n", __func__);
 220                 goto out;
 221         }
 222
 223         if (!intc[active_cnt].domain) {
 224                 pr_err("%s: Unable to add irq domain!\n", __func__);
 225                 goto out;
 226         }
 227
 228         vt8500_init_irq_hw(intc[active_cnt].base);
 229
 230         pr_info("vt8500-irq: Added interrupt controller\n");
 231
 232         active_cnt++;
 233
 234         /* check if this is a slaved controller */
 235         if (of_irq_count(np) != 0) {
 236                 /* check that we have the correct number of interrupts */
 237                 if (of_irq_count(np) != 8) {
 238                         pr_err("%s: Incorrect IRQ map for slaved controller\n",
 239                                         __func__);
 240                         return -EINVAL;
 241                 }
 242
 243                 for (i = 0; i < 8; i++) {
 244                         irq = irq_of_parse_and_map(np, i);
 245                         enable_irq(irq);
 246                 }
 247
 248                 pr_info("vt8500-irq: Enabled slave->parent interrupts\n");
 249         }
 250 out:
 251         return 0;
 252 }
 253