xref: /openbmc/linux/arch/arm/mach-imx/avic.c (revision f9834f18)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright 2004-2007 Freescale Semiconductor, Inc. All Rights Reserved.
4  * Copyright 2008 Juergen Beisert, kernel@pengutronix.de
5  */
6 
7 #include <linux/module.h>
8 #include <linux/irq.h>
9 #include <linux/irqdomain.h>
10 #include <linux/io.h>
11 #include <linux/of.h>
12 #include <linux/of_address.h>
13 #include <asm/mach/irq.h>
14 #include <asm/exception.h>
15 
16 #include "common.h"
17 #include "hardware.h"
18 #include "irq-common.h"
19 
20 #define AVIC_INTCNTL		0x00	/* int control reg */
21 #define AVIC_NIMASK		0x04	/* int mask reg */
22 #define AVIC_INTENNUM		0x08	/* int enable number reg */
23 #define AVIC_INTDISNUM		0x0C	/* int disable number reg */
24 #define AVIC_INTENABLEH		0x10	/* int enable reg high */
25 #define AVIC_INTENABLEL		0x14	/* int enable reg low */
26 #define AVIC_INTTYPEH		0x18	/* int type reg high */
27 #define AVIC_INTTYPEL		0x1C	/* int type reg low */
28 #define AVIC_NIPRIORITY(x)	(0x20 + 4 * (7 - (x))) /* int priority */
29 #define AVIC_NIVECSR		0x40	/* norm int vector/status */
30 #define AVIC_FIVECSR		0x44	/* fast int vector/status */
31 #define AVIC_INTSRCH		0x48	/* int source reg high */
32 #define AVIC_INTSRCL		0x4C	/* int source reg low */
33 #define AVIC_INTFRCH		0x50	/* int force reg high */
34 #define AVIC_INTFRCL		0x54	/* int force reg low */
35 #define AVIC_NIPNDH		0x58	/* norm int pending high */
36 #define AVIC_NIPNDL		0x5C	/* norm int pending low */
37 #define AVIC_FIPNDH		0x60	/* fast int pending high */
38 #define AVIC_FIPNDL		0x64	/* fast int pending low */
39 
40 #define AVIC_NUM_IRQS 64
41 
42 /* low power interrupt mask registers */
43 #define MX25_CCM_LPIMR0	0x68
44 #define MX25_CCM_LPIMR1	0x6C
45 
46 static void __iomem *avic_base;
47 static void __iomem *mx25_ccm_base;
48 static struct irq_domain *domain;
49 
50 #ifdef CONFIG_FIQ
51 static int avic_set_irq_fiq(unsigned int hwirq, unsigned int type)
52 {
53 	unsigned int irqt;
54 
55 	if (hwirq >= AVIC_NUM_IRQS)
56 		return -EINVAL;
57 
58 	if (hwirq < AVIC_NUM_IRQS / 2) {
59 		irqt = imx_readl(avic_base + AVIC_INTTYPEL) & ~(1 << hwirq);
60 		imx_writel(irqt | (!!type << hwirq), avic_base + AVIC_INTTYPEL);
61 	} else {
62 		hwirq -= AVIC_NUM_IRQS / 2;
63 		irqt = imx_readl(avic_base + AVIC_INTTYPEH) & ~(1 << hwirq);
64 		imx_writel(irqt | (!!type << hwirq), avic_base + AVIC_INTTYPEH);
65 	}
66 
67 	return 0;
68 }
69 #endif /* CONFIG_FIQ */
70 
71 
72 static struct mxc_extra_irq avic_extra_irq = {
73 #ifdef CONFIG_FIQ
74 	.set_irq_fiq = avic_set_irq_fiq,
75 #endif
76 };
77 
78 #ifdef CONFIG_PM
79 static u32 avic_saved_mask_reg[2];
80 
81 static void avic_irq_suspend(struct irq_data *d)
82 {
83 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
84 	struct irq_chip_type *ct = gc->chip_types;
85 	int idx = d->hwirq >> 5;
86 
87 	avic_saved_mask_reg[idx] = imx_readl(avic_base + ct->regs.mask);
88 	imx_writel(gc->wake_active, avic_base + ct->regs.mask);
89 
90 	if (mx25_ccm_base) {
91 		u8 offs = d->hwirq < AVIC_NUM_IRQS / 2 ?
92 			MX25_CCM_LPIMR0 : MX25_CCM_LPIMR1;
93 		/*
94 		 * The interrupts which are still enabled will be used as wakeup
95 		 * sources. Allow those interrupts in low-power mode.
96 		 * The LPIMR registers use 0 to allow an interrupt, the AVIC
97 		 * registers use 1.
98 		 */
99 		imx_writel(~gc->wake_active, mx25_ccm_base + offs);
100 	}
101 }
102 
103 static void avic_irq_resume(struct irq_data *d)
104 {
105 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
106 	struct irq_chip_type *ct = gc->chip_types;
107 	int idx = d->hwirq >> 5;
108 
109 	imx_writel(avic_saved_mask_reg[idx], avic_base + ct->regs.mask);
110 
111 	if (mx25_ccm_base) {
112 		u8 offs = d->hwirq < AVIC_NUM_IRQS / 2 ?
113 			MX25_CCM_LPIMR0 : MX25_CCM_LPIMR1;
114 
115 		imx_writel(0xffffffff, mx25_ccm_base + offs);
116 	}
117 }
118 
119 #else
120 #define avic_irq_suspend NULL
121 #define avic_irq_resume NULL
122 #endif
123 
124 static __init void avic_init_gc(int idx, unsigned int irq_start)
125 {
126 	struct irq_chip_generic *gc;
127 	struct irq_chip_type *ct;
128 
129 	gc = irq_alloc_generic_chip("mxc-avic", 1, irq_start, avic_base,
130 				    handle_level_irq);
131 	gc->private = &avic_extra_irq;
132 	gc->wake_enabled = IRQ_MSK(32);
133 
134 	ct = gc->chip_types;
135 	ct->chip.irq_mask = irq_gc_mask_clr_bit;
136 	ct->chip.irq_unmask = irq_gc_mask_set_bit;
137 	ct->chip.irq_ack = irq_gc_mask_clr_bit;
138 	ct->chip.irq_set_wake = irq_gc_set_wake;
139 	ct->chip.irq_suspend = avic_irq_suspend;
140 	ct->chip.irq_resume = avic_irq_resume;
141 	ct->regs.mask = !idx ? AVIC_INTENABLEL : AVIC_INTENABLEH;
142 	ct->regs.ack = ct->regs.mask;
143 
144 	irq_setup_generic_chip(gc, IRQ_MSK(32), 0, IRQ_NOREQUEST, 0);
145 }
146 
147 static void __exception_irq_entry avic_handle_irq(struct pt_regs *regs)
148 {
149 	u32 nivector;
150 
151 	do {
152 		nivector = imx_readl(avic_base + AVIC_NIVECSR) >> 16;
153 		if (nivector == 0xffff)
154 			break;
155 
156 		handle_domain_irq(domain, nivector, regs);
157 	} while (1);
158 }
159 
160 /*
161  * This function initializes the AVIC hardware and disables all the
162  * interrupts. It registers the interrupt enable and disable functions
163  * to the kernel for each interrupt source.
164  */
165 void __init mxc_init_irq(void __iomem *irqbase)
166 {
167 	struct device_node *np;
168 	int irq_base;
169 	int i;
170 
171 	avic_base = irqbase;
172 
173 	np = of_find_compatible_node(NULL, NULL, "fsl,imx25-ccm");
174 	mx25_ccm_base = of_iomap(np, 0);
175 
176 	if (mx25_ccm_base) {
177 		/*
178 		 * By default, we mask all interrupts. We set the actual mask
179 		 * before we go into low-power mode.
180 		 */
181 		imx_writel(0xffffffff, mx25_ccm_base + MX25_CCM_LPIMR0);
182 		imx_writel(0xffffffff, mx25_ccm_base + MX25_CCM_LPIMR1);
183 	}
184 
185 	/* put the AVIC into the reset value with
186 	 * all interrupts disabled
187 	 */
188 	imx_writel(0, avic_base + AVIC_INTCNTL);
189 	imx_writel(0x1f, avic_base + AVIC_NIMASK);
190 
191 	/* disable all interrupts */
192 	imx_writel(0, avic_base + AVIC_INTENABLEH);
193 	imx_writel(0, avic_base + AVIC_INTENABLEL);
194 
195 	/* all IRQ no FIQ */
196 	imx_writel(0, avic_base + AVIC_INTTYPEH);
197 	imx_writel(0, avic_base + AVIC_INTTYPEL);
198 
199 	irq_base = irq_alloc_descs(-1, 0, AVIC_NUM_IRQS, numa_node_id());
200 	WARN_ON(irq_base < 0);
201 
202 	np = of_find_compatible_node(NULL, NULL, "fsl,avic");
203 	domain = irq_domain_add_legacy(np, AVIC_NUM_IRQS, irq_base, 0,
204 				       &irq_domain_simple_ops, NULL);
205 	WARN_ON(!domain);
206 
207 	for (i = 0; i < AVIC_NUM_IRQS / 32; i++, irq_base += 32)
208 		avic_init_gc(i, irq_base);
209 
210 	/* Set default priority value (0) for all IRQ's */
211 	for (i = 0; i < 8; i++)
212 		imx_writel(0, avic_base + AVIC_NIPRIORITY(i));
213 
214 	set_handle_irq(avic_handle_irq);
215 
216 #ifdef CONFIG_FIQ
217 	/* Initialize FIQ */
218 	init_FIQ(FIQ_START);
219 #endif
220 
221 	printk(KERN_INFO "MXC IRQ initialized\n");
222 }
223