1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *
4  * Copyright (C) 2013 John Crispin <john@phrozen.org>
5  */
6 
7 #include <linux/interrupt.h>
8 #include <linux/of_platform.h>
9 #include <linux/of_irq.h>
10 
11 #include <asm/mach-ralink/ralink_regs.h>
12 
13 #define REG_ILL_ACC_ADDR	0x10
14 #define REG_ILL_ACC_TYPE	0x14
15 
16 #define ILL_INT_STATUS		BIT(31)
17 #define ILL_ACC_WRITE		BIT(30)
18 #define ILL_ACC_LEN_M		0xff
19 #define ILL_ACC_OFF_M		0xf
20 #define ILL_ACC_OFF_S		16
21 #define ILL_ACC_ID_M		0x7
22 #define ILL_ACC_ID_S		8
23 
24 #define	DRV_NAME		"ill_acc"
25 
26 static const char * const ill_acc_ids[] = {
27 	"cpu", "dma", "ppe", "pdma rx", "pdma tx", "pci/e", "wmac", "usb",
28 };
29 
ill_acc_irq_handler(int irq,void * _priv)30 static irqreturn_t ill_acc_irq_handler(int irq, void *_priv)
31 {
32 	struct device *dev = (struct device *) _priv;
33 	u32 addr = rt_memc_r32(REG_ILL_ACC_ADDR);
34 	u32 type = rt_memc_r32(REG_ILL_ACC_TYPE);
35 
36 	dev_err(dev, "illegal %s access from %s - addr:0x%08x offset:%d len:%d\n",
37 		(type & ILL_ACC_WRITE) ? ("write") : ("read"),
38 		ill_acc_ids[(type >> ILL_ACC_ID_S) & ILL_ACC_ID_M],
39 		addr, (type >> ILL_ACC_OFF_S) & ILL_ACC_OFF_M,
40 		type & ILL_ACC_LEN_M);
41 
42 	rt_memc_w32(ILL_INT_STATUS, REG_ILL_ACC_TYPE);
43 
44 	return IRQ_HANDLED;
45 }
46 
ill_acc_of_setup(void)47 static int __init ill_acc_of_setup(void)
48 {
49 	struct platform_device *pdev;
50 	struct device_node *np;
51 	int irq;
52 
53 	/* somehow this driver breaks on RT5350 */
54 	if (of_machine_is_compatible("ralink,rt5350-soc"))
55 		return -EINVAL;
56 
57 	np = of_find_compatible_node(NULL, NULL, "ralink,rt3050-memc");
58 	if (!np)
59 		return -EINVAL;
60 
61 	pdev = of_find_device_by_node(np);
62 	if (!pdev) {
63 		pr_err("%pOFn: failed to lookup pdev\n", np);
64 		of_node_put(np);
65 		return -EINVAL;
66 	}
67 
68 	irq = irq_of_parse_and_map(np, 0);
69 	of_node_put(np);
70 	if (!irq) {
71 		dev_err(&pdev->dev, "failed to get irq\n");
72 		put_device(&pdev->dev);
73 		return -EINVAL;
74 	}
75 
76 	if (request_irq(irq, ill_acc_irq_handler, 0, "ill_acc", &pdev->dev)) {
77 		dev_err(&pdev->dev, "failed to request irq\n");
78 		put_device(&pdev->dev);
79 		return -EINVAL;
80 	}
81 
82 	rt_memc_w32(ILL_INT_STATUS, REG_ILL_ACC_TYPE);
83 
84 	dev_info(&pdev->dev, "irq registered\n");
85 
86 	return 0;
87 }
88 
89 arch_initcall(ill_acc_of_setup);
90