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_PB11MP_SYS_PLD_CTRL1	0x74
14 #define VERSATILE_LOCK_VAL		0xA05F
15 #define PLD_INTMODE_MASK		BIT(22)|BIT(23)|BIT(24)
16 #define PLD_INTMODE_LEGACY		0x0
17 #define PLD_INTMODE_NEW_DCC		BIT(22)
18 #define PLD_INTMODE_NEW_NO_DCC		BIT(23)
19 #define PLD_INTMODE_FIQ_ENABLE		BIT(24)
20 
21 static int __init
22 realview_gic_of_init(struct device_node *node, struct device_node *parent)
23 {
24 	static struct regmap *map;
25 
26 	/* The PB11MPCore GIC needs to be configured in the syscon */
27 	map = syscon_regmap_lookup_by_compatible("arm,realview-pb11mp-syscon");
28 	if (!IS_ERR(map)) {
29 		/* new irq mode with no DCC */
30 		regmap_write(map, REALVIEW_SYS_LOCK_OFFSET,
31 			     VERSATILE_LOCK_VAL);
32 		regmap_update_bits(map, REALVIEW_PB11MP_SYS_PLD_CTRL1,
33 				   PLD_INTMODE_NEW_NO_DCC,
34 				   PLD_INTMODE_MASK);
35 		regmap_write(map, REALVIEW_SYS_LOCK_OFFSET, 0x0000);
36 		pr_info("TC11MP GIC: set up interrupt controller to NEW mode, no DCC\n");
37 	} else {
38 		pr_err("TC11MP GIC setup: could not find syscon\n");
39 		return -ENXIO;
40 	}
41 	return gic_of_init(node, parent);
42 }
43 IRQCHIP_DECLARE(armtc11mp_gic, "arm,tc11mp-gic", realview_gic_of_init);
44