linux/drivers/irqchip/irq-davinci-aintc.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2//
   3// Copyright (C) 2006, 2019 Texas Instruments.
   4//
   5// Interrupt handler for DaVinci boards.
   6
   7#include <linux/kernel.h>
   8#include <linux/init.h>
   9#include <linux/interrupt.h>
  10#include <linux/irq.h>
  11#include <linux/irqchip/irq-davinci-aintc.h>
  12#include <linux/io.h>
  13#include <linux/irqdomain.h>
  14
  15#include <asm/exception.h>
  16
  17#define DAVINCI_AINTC_FIQ_REG0          0x00
  18#define DAVINCI_AINTC_FIQ_REG1          0x04
  19#define DAVINCI_AINTC_IRQ_REG0          0x08
  20#define DAVINCI_AINTC_IRQ_REG1          0x0c
  21#define DAVINCI_AINTC_IRQ_IRQENTRY      0x14
  22#define DAVINCI_AINTC_IRQ_ENT_REG0      0x18
  23#define DAVINCI_AINTC_IRQ_ENT_REG1      0x1c
  24#define DAVINCI_AINTC_IRQ_INCTL_REG     0x20
  25#define DAVINCI_AINTC_IRQ_EABASE_REG    0x24
  26#define DAVINCI_AINTC_IRQ_INTPRI0_REG   0x30
  27#define DAVINCI_AINTC_IRQ_INTPRI7_REG   0x4c
  28
  29static void __iomem *davinci_aintc_base;
  30static struct irq_domain *davinci_aintc_irq_domain;
  31
  32static inline void davinci_aintc_writel(unsigned long value, int offset)
  33{
  34        writel_relaxed(value, davinci_aintc_base + offset);
  35}
  36
  37static inline unsigned long davinci_aintc_readl(int offset)
  38{
  39        return readl_relaxed(davinci_aintc_base + offset);
  40}
  41
  42static __init void
  43davinci_aintc_setup_gc(void __iomem *base,
  44                       unsigned int irq_start, unsigned int num)
  45{
  46        struct irq_chip_generic *gc;
  47        struct irq_chip_type *ct;
  48
  49        gc = irq_get_domain_generic_chip(davinci_aintc_irq_domain, irq_start);
  50        gc->reg_base = base;
  51        gc->irq_base = irq_start;
  52
  53        ct = gc->chip_types;
  54        ct->chip.irq_ack = irq_gc_ack_set_bit;
  55        ct->chip.irq_mask = irq_gc_mask_clr_bit;
  56        ct->chip.irq_unmask = irq_gc_mask_set_bit;
  57
  58        ct->regs.ack = DAVINCI_AINTC_IRQ_REG0;
  59        ct->regs.mask = DAVINCI_AINTC_IRQ_ENT_REG0;
  60        irq_setup_generic_chip(gc, IRQ_MSK(num), IRQ_GC_INIT_MASK_CACHE,
  61                               IRQ_NOREQUEST | IRQ_NOPROBE, 0);
  62}
  63
  64static asmlinkage void __exception_irq_entry
  65davinci_aintc_handle_irq(struct pt_regs *regs)
  66{
  67        int irqnr = davinci_aintc_readl(DAVINCI_AINTC_IRQ_IRQENTRY);
  68
  69        /*
  70         * Use the formula for entry vector index generation from section
  71         * 8.3.3 of the manual.
  72         */
  73        irqnr >>= 2;
  74        irqnr -= 1;
  75
  76        handle_domain_irq(davinci_aintc_irq_domain, irqnr, regs);
  77}
  78
  79/* ARM Interrupt Controller Initialization */
  80void __init davinci_aintc_init(const struct davinci_aintc_config *config)
  81{
  82        unsigned int irq_off, reg_off, prio, shift;
  83        void __iomem *req;
  84        int ret, irq_base;
  85        const u8 *prios;
  86
  87        req = request_mem_region(config->reg.start,
  88                                 resource_size(&config->reg),
  89                                 "davinci-cp-intc");
  90        if (!req) {
  91                pr_err("%s: register range busy\n", __func__);
  92                return;
  93        }
  94
  95        davinci_aintc_base = ioremap(config->reg.start,
  96                                     resource_size(&config->reg));
  97        if (!davinci_aintc_base) {
  98                pr_err("%s: unable to ioremap register range\n", __func__);
  99                return;
 100        }
 101
 102        /* Clear all interrupt requests */
 103        davinci_aintc_writel(~0x0, DAVINCI_AINTC_FIQ_REG0);
 104        davinci_aintc_writel(~0x0, DAVINCI_AINTC_FIQ_REG1);
 105        davinci_aintc_writel(~0x0, DAVINCI_AINTC_IRQ_REG0);
 106        davinci_aintc_writel(~0x0, DAVINCI_AINTC_IRQ_REG1);
 107
 108        /* Disable all interrupts */
 109        davinci_aintc_writel(0x0, DAVINCI_AINTC_IRQ_ENT_REG0);
 110        davinci_aintc_writel(0x0, DAVINCI_AINTC_IRQ_ENT_REG1);
 111
 112        /* Interrupts disabled immediately, IRQ entry reflects all */
 113        davinci_aintc_writel(0x0, DAVINCI_AINTC_IRQ_INCTL_REG);
 114
 115        /* we don't use the hardware vector table, just its entry addresses */
 116        davinci_aintc_writel(0, DAVINCI_AINTC_IRQ_EABASE_REG);
 117
 118        /* Clear all interrupt requests */
 119        davinci_aintc_writel(~0x0, DAVINCI_AINTC_FIQ_REG0);
 120        davinci_aintc_writel(~0x0, DAVINCI_AINTC_FIQ_REG1);
 121        davinci_aintc_writel(~0x0, DAVINCI_AINTC_IRQ_REG0);
 122        davinci_aintc_writel(~0x0, DAVINCI_AINTC_IRQ_REG1);
 123
 124        prios = config->prios;
 125        for (reg_off = DAVINCI_AINTC_IRQ_INTPRI0_REG;
 126             reg_off <= DAVINCI_AINTC_IRQ_INTPRI7_REG; reg_off += 4) {
 127                for (shift = 0, prio = 0; shift < 32; shift += 4, prios++)
 128                        prio |= (*prios & 0x07) << shift;
 129                davinci_aintc_writel(prio, reg_off);
 130        }
 131
 132        irq_base = irq_alloc_descs(-1, 0, config->num_irqs, 0);
 133        if (irq_base < 0) {
 134                pr_err("%s: unable to allocate interrupt descriptors: %d\n",
 135                       __func__, irq_base);
 136                return;
 137        }
 138
 139        davinci_aintc_irq_domain = irq_domain_add_legacy(NULL,
 140                                                config->num_irqs, irq_base, 0,
 141                                                &irq_domain_simple_ops, NULL);
 142        if (!davinci_aintc_irq_domain) {
 143                pr_err("%s: unable to create interrupt domain\n", __func__);
 144                return;
 145        }
 146
 147        ret = irq_alloc_domain_generic_chips(davinci_aintc_irq_domain, 32, 1,
 148                                             "AINTC", handle_edge_irq,
 149                                             IRQ_NOREQUEST | IRQ_NOPROBE, 0, 0);
 150        if (ret) {
 151                pr_err("%s: unable to allocate generic irq chips for domain\n",
 152                       __func__);
 153                return;
 154        }
 155
 156        for (irq_off = 0, reg_off = 0;
 157             irq_off < config->num_irqs;
 158             irq_off += 32, reg_off += 0x04)
 159                davinci_aintc_setup_gc(davinci_aintc_base + reg_off,
 160                                       irq_base + irq_off, 32);
 161
 162        set_handle_irq(davinci_aintc_handle_irq);
 163}
 164