xref: /linux/arch/mips/ralink/ill_acc.c (revision 4e0ae876f77bc01a7e77724dea57b4b82bd53244)
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("%pOFn: failed to lookup pdev\n", np);
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);
88