1 /*
2  * Special GIC quirks for the ARM RealView
3  * Copyright (C) 2015 Linus Walleij
4  */
5 #include <linux/of.h>
6 #include <linux/regmap.h>
7 #include <linux/mfd/syscon.h>
8 #include <linux/bitops.h>
9 #include <linux/irqchip.h>
10 #include <linux/irqchip/arm-gic.h>
11 
12 #define REALVIEW_SYS_LOCK_OFFSET	0x20
13 #define REALVIEW_SYS_PLD_CTRL1		0x74
14 #define REALVIEW_EB_REVB_SYS_PLD_CTRL1	0xD8
15 #define VERSATILE_LOCK_VAL		0xA05F
16 #define PLD_INTMODE_MASK		BIT(22)|BIT(23)|BIT(24)
17 #define PLD_INTMODE_LEGACY		0x0
18 #define PLD_INTMODE_NEW_DCC		BIT(22)
19 #define PLD_INTMODE_NEW_NO_DCC		BIT(23)
20 #define PLD_INTMODE_FIQ_ENABLE		BIT(24)
21 
22 /* For some reason RealView EB Rev B moved this register */
23 static const struct of_device_id syscon_pldset_of_match[] = {
24 	{
25 		.compatible = "arm,realview-eb11mp-revb-syscon",
26 		.data = (void *)REALVIEW_EB_REVB_SYS_PLD_CTRL1,
27 	},
28 	{
29 		.compatible = "arm,realview-eb11mp-revc-syscon",
30 		.data = (void *)REALVIEW_SYS_PLD_CTRL1,
31 	},
32 	{
33 		.compatible = "arm,realview-eb-syscon",
34 		.data = (void *)REALVIEW_SYS_PLD_CTRL1,
35 	},
36 	{
37 		.compatible = "arm,realview-pb11mp-syscon",
38 		.data = (void *)REALVIEW_SYS_PLD_CTRL1,
39 	},
40 	{},
41 };
42 
43 static int __init
44 realview_gic_of_init(struct device_node *node, struct device_node *parent)
45 {
46 	static struct regmap *map;
47 	struct device_node *np;
48 	const struct of_device_id *gic_id;
49 	u32 pld1_ctrl;
50 
51 	np = of_find_matching_node_and_match(NULL, syscon_pldset_of_match,
52 					     &gic_id);
53 	if (!np)
54 		return -ENODEV;
55 	pld1_ctrl = (u32)gic_id->data;
56 
57 	/* The PB11MPCore GIC needs to be configured in the syscon */
58 	map = syscon_node_to_regmap(np);
59 	if (!IS_ERR(map)) {
60 		/* new irq mode with no DCC */
61 		regmap_write(map, REALVIEW_SYS_LOCK_OFFSET,
62 			     VERSATILE_LOCK_VAL);
63 		regmap_update_bits(map, pld1_ctrl,
64 				   PLD_INTMODE_NEW_NO_DCC,
65 				   PLD_INTMODE_MASK);
66 		regmap_write(map, REALVIEW_SYS_LOCK_OFFSET, 0x0000);
67 		pr_info("RealView GIC: set up interrupt controller to NEW mode, no DCC\n");
68 	} else {
69 		pr_err("RealView GIC setup: could not find syscon\n");
70 		return -ENODEV;
71 	}
72 	return gic_of_init(node, parent);
73 }
74 IRQCHIP_DECLARE(armtc11mp_gic, "arm,tc11mp-gic", realview_gic_of_init);
75 IRQCHIP_DECLARE(armeb11mp_gic, "arm,eb11mp-gic", realview_gic_of_init);
76