drivers/irqchip/irq-mxs.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_address.h>
  26 #include <linux/of_irq.h>
  27 #include <linux/stmp_device.h>
  28 #include <asm/exception.h>
  29
  30 #include "irqchip.h"
  31
  32 #define HW_ICOLL_VECTOR                         0x0000
  33 #define HW_ICOLL_LEVELACK                       0x0010
  34 #define HW_ICOLL_CTRL                           0x0020
  35 #define HW_ICOLL_STAT_OFFSET                    0x0070
  36 #define HW_ICOLL_INTERRUPTn_SET(n)              (0x0124 + (n) * 0x10)
  37 #define HW_ICOLL_INTERRUPTn_CLR(n)              (0x0128 + (n) * 0x10)
  38 #define BM_ICOLL_INTERRUPTn_ENABLE              0x00000004
  39 #define BV_ICOLL_LEVELACK_IRQLEVELACK__LEVEL0   0x1
  40
  41 #define ICOLL_NUM_IRQS          128
  42
  43 static void __iomem *icoll_base;
  44 static struct irq_domain *icoll_domain;
  45
  46 static void icoll_ack_irq(struct irq_data *d)
  47 {
  48         /*
  49          * The Interrupt Collector is able to prioritize irqs.
  50          * Currently only level 0 is used. So acking can use
  51          * BV_ICOLL_LEVELACK_IRQLEVELACK__LEVEL0 unconditionally.
  52          */
  53         __raw_writel(BV_ICOLL_LEVELACK_IRQLEVELACK__LEVEL0,
  54                         icoll_base + HW_ICOLL_LEVELACK);
  55 }
  56
  57 static void icoll_mask_irq(struct irq_data *d)
  58 {
  59         __raw_writel(BM_ICOLL_INTERRUPTn_ENABLE,
  60                         icoll_base + HW_ICOLL_INTERRUPTn_CLR(d->hwirq));
  61 }
  62
  63 static void icoll_unmask_irq(struct irq_data *d)
  64 {
  65         __raw_writel(BM_ICOLL_INTERRUPTn_ENABLE,
  66                         icoll_base + HW_ICOLL_INTERRUPTn_SET(d->hwirq));
  67 }
  68
  69 static struct irq_chip mxs_icoll_chip = {
  70         .irq_ack = icoll_ack_irq,
  71         .irq_mask = icoll_mask_irq,
  72         .irq_unmask = icoll_unmask_irq,
  73 };
  74
  75 asmlinkage void __exception_irq_entry icoll_handle_irq(struct pt_regs *regs)
  76 {
  77         u32 irqnr;
  78
  79         irqnr = __raw_readl(icoll_base + HW_ICOLL_STAT_OFFSET);
  80         __raw_writel(irqnr, icoll_base + HW_ICOLL_VECTOR);
  81         handle_domain_irq(icoll_domain, irqnr, regs);
  82 }
  83
  84 static int icoll_irq_domain_map(struct irq_domain *d, unsigned int virq,
  85                                 irq_hw_number_t hw)
  86 {
  87         irq_set_chip_and_handler(virq, &mxs_icoll_chip, handle_level_irq);
  88         set_irq_flags(virq, IRQF_VALID);
  89
  90         return 0;
  91 }
  92
  93 static struct irq_domain_ops icoll_irq_domain_ops = {
  94         .map = icoll_irq_domain_map,
  95         .xlate = irq_domain_xlate_onecell,
  96 };
  97
  98 static int __init icoll_of_init(struct device_node *np,
  99                           struct device_node *interrupt_parent)
 100 {
 101         icoll_base = of_iomap(np, 0);
 102         WARN_ON(!icoll_base);
 103
 104         /*
 105          * Interrupt Collector reset, which initializes the priority
 106          * for each irq to level 0.
 107          */
 108         stmp_reset_block(icoll_base + HW_ICOLL_CTRL);
 109
 110         icoll_domain = irq_domain_add_linear(np, ICOLL_NUM_IRQS,
 111                                              &icoll_irq_domain_ops, NULL);
 112         return icoll_domain ? 0 : -ENODEV;
 113 }
 114 IRQCHIP_DECLARE(mxs, "fsl,icoll", icoll_of_init);