arch/arm/mach-mxs/icoll.c

   1 /*
   2  * Copyright (C) 2009-2010 Freescale Semiconductor, Inc. All Rights Reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along
  15  * with this program; if not, write to the Free Software Foundation, Inc.,
  16  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  17  */
  18
  19 #include <linux/kernel.h>
  20 #include <linux/init.h>
  21 #include <linux/irq.h>
  22 #include <linux/irqdomain.h>
  23 #include <linux/io.h>
  24 #include <linux/of.h>
  25 #include <linux/of_irq.h>
  26 #include <asm/exception.h>
  27 #include <mach/mxs.h>
  28 #include <mach/common.h>
  29
  30 #define HW_ICOLL_VECTOR                         0x0000
  31 #define HW_ICOLL_LEVELACK                       0x0010
  32 #define HW_ICOLL_CTRL                           0x0020
  33 #define HW_ICOLL_STAT_OFFSET                    0x0070
  34 #define HW_ICOLL_INTERRUPTn_SET(n)              (0x0124 + (n) * 0x10)
  35 #define HW_ICOLL_INTERRUPTn_CLR(n)              (0x0128 + (n) * 0x10)
  36 #define BM_ICOLL_INTERRUPTn_ENABLE              0x00000004
  37 #define BV_ICOLL_LEVELACK_IRQLEVELACK__LEVEL0   0x1
  38
  39 #define ICOLL_NUM_IRQS          128
  40
  41 static void __iomem *icoll_base = MXS_IO_ADDRESS(MXS_ICOLL_BASE_ADDR);
  42 static struct irq_domain *icoll_domain;
  43
  44 static void icoll_ack_irq(struct irq_data *d)
  45 {
  46         /*
  47          * The Interrupt Collector is able to prioritize irqs.
  48          * Currently only level 0 is used. So acking can use
  49          * BV_ICOLL_LEVELACK_IRQLEVELACK__LEVEL0 unconditionally.
  50          */
  51         __raw_writel(BV_ICOLL_LEVELACK_IRQLEVELACK__LEVEL0,
  52                         icoll_base + HW_ICOLL_LEVELACK);
  53 }
  54
  55 static void icoll_mask_irq(struct irq_data *d)
  56 {
  57         __raw_writel(BM_ICOLL_INTERRUPTn_ENABLE,
  58                         icoll_base + HW_ICOLL_INTERRUPTn_CLR(d->hwirq));
  59 }
  60
  61 static void icoll_unmask_irq(struct irq_data *d)
  62 {
  63         __raw_writel(BM_ICOLL_INTERRUPTn_ENABLE,
  64                         icoll_base + HW_ICOLL_INTERRUPTn_SET(d->hwirq));
  65 }
  66
  67 static struct irq_chip mxs_icoll_chip = {
  68         .irq_ack = icoll_ack_irq,
  69         .irq_mask = icoll_mask_irq,
  70         .irq_unmask = icoll_unmask_irq,
  71 };
  72
  73 asmlinkage void __exception_irq_entry icoll_handle_irq(struct pt_regs *regs)
  74 {
  75         u32 irqnr;
  76
  77         do {
  78                 irqnr = __raw_readl(icoll_base + HW_ICOLL_STAT_OFFSET);
  79                 if (irqnr != 0x7f) {
  80                         __raw_writel(irqnr, icoll_base + HW_ICOLL_VECTOR);
  81                         irqnr = irq_find_mapping(icoll_domain, irqnr);
  82                         handle_IRQ(irqnr, regs);
  83                         continue;
  84                 }
  85                 break;
  86         } while (1);
  87 }
  88
  89 static int icoll_irq_domain_map(struct irq_domain *d, unsigned int virq,
  90                                 irq_hw_number_t hw)
  91 {
  92         irq_set_chip_and_handler(virq, &mxs_icoll_chip, handle_level_irq);
  93         set_irq_flags(virq, IRQF_VALID);
  94
  95         return 0;
  96 }
  97
  98 static struct irq_domain_ops icoll_irq_domain_ops = {
  99         .map = icoll_irq_domain_map,
 100         .xlate = irq_domain_xlate_onecell,
 101 };
 102
 103 static void __init icoll_of_init(struct device_node *np,
 104                           struct device_node *interrupt_parent)
 105 {
 106         /*
 107          * Interrupt Collector reset, which initializes the priority
 108          * for each irq to level 0.
 109          */
 110         mxs_reset_block(icoll_base + HW_ICOLL_CTRL);
 111
 112         icoll_domain = irq_domain_add_linear(np, ICOLL_NUM_IRQS,
 113                                              &icoll_irq_domain_ops, NULL);
 114         WARN_ON(!icoll_domain);
 115 }
 116
 117 static const struct of_device_id icoll_of_match[] __initconst = {
 118         {.compatible = "fsl,icoll", .data = icoll_of_init},
 119         { /* sentinel */ }
 120 };
 121
 122 void __init icoll_init_irq(void)
 123 {
 124         of_irq_init(icoll_of_match);
 125 }