arch/mips/ralink/ill_acc.c

   1 /*
   2  * This program is free software; you can redistribute it and/or modify it
   3  * under the terms of the GNU General Public License version 2 as published
   4  * by the Free Software Foundation.
   5  *
   6  * Copyright (C) 2013 John Crispin <john@phrozen.org>
   7  */
   8
   9 #include <linux/interrupt.h>
  10 #include <linux/of_platform.h>
  11 #include <linux/of_irq.h>
  12
  13 #include <asm/mach-ralink/ralink_regs.h>
  14
  15 #define REG_ILL_ACC_ADDR        0x10
  16 #define REG_ILL_ACC_TYPE        0x14
  17
  18 #define ILL_INT_STATUS          BIT(31)
  19 #define ILL_ACC_WRITE           BIT(30)
  20 #define ILL_ACC_LEN_M           0xff
  21 #define ILL_ACC_OFF_M           0xf
  22 #define ILL_ACC_OFF_S           16
  23 #define ILL_ACC_ID_M            0x7
  24 #define ILL_ACC_ID_S            8
  25
  26 #define DRV_NAME                "ill_acc"
  27
  28 static const char * const ill_acc_ids[] = {
  29         "cpu", "dma", "ppe", "pdma rx", "pdma tx", "pci/e", "wmac", "usb",
  30 };
  31
  32 static irqreturn_t ill_acc_irq_handler(int irq, void *_priv)
  33 {
  34         struct device *dev = (struct device *) _priv;
  35         u32 addr = rt_memc_r32(REG_ILL_ACC_ADDR);
  36         u32 type = rt_memc_r32(REG_ILL_ACC_TYPE);
  37
  38         dev_err(dev, "illegal %s access from %s - addr:0x%08x offset:%d len:%d\n",
  39                 (type & ILL_ACC_WRITE) ? ("write") : ("read"),
  40                 ill_acc_ids[(type >> ILL_ACC_ID_S) & ILL_ACC_ID_M],
  41                 addr, (type >> ILL_ACC_OFF_S) & ILL_ACC_OFF_M,
  42                 type & ILL_ACC_LEN_M);
  43
  44         rt_memc_w32(ILL_INT_STATUS, REG_ILL_ACC_TYPE);
  45
  46         return IRQ_HANDLED;
  47 }
  48
  49 static int __init ill_acc_of_setup(void)
  50 {
  51         struct platform_device *pdev;
  52         struct device_node *np;
  53         int irq;
  54
  55         /* somehow this driver breaks on RT5350 */
  56         if (of_machine_is_compatible("ralink,rt5350-soc"))
  57                 return -EINVAL;
  58
  59         np = of_find_compatible_node(NULL, NULL, "ralink,rt3050-memc");
  60         if (!np)
  61                 return -EINVAL;
  62
  63         pdev = of_find_device_by_node(np);
  64         if (!pdev) {
  65                 pr_err("%s: failed to lookup pdev\n", np->name);
  66                 return -EINVAL;
  67         }
  68
  69         irq = irq_of_parse_and_map(np, 0);
  70         if (!irq) {
  71                 dev_err(&pdev->dev, "failed to get irq\n");
  72                 return -EINVAL;
  73         }
  74
  75         if (request_irq(irq, ill_acc_irq_handler, 0, "ill_acc", &pdev->dev)) {
  76                 dev_err(&pdev->dev, "failed to request irq\n");
  77                 return -EINVAL;
  78         }
  79
  80         rt_memc_w32(ILL_INT_STATUS, REG_ILL_ACC_TYPE);
  81
  82         dev_info(&pdev->dev, "irq registered\n");
  83
  84         return 0;
  85 }
  86
  87 arch_initcall(ill_acc_of_setup);