xref: /openbmc/linux/arch/arm/mach-imx/avic.c (revision 35267cea)
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/irqchip.h>
11 #include <linux/io.h>
12 #include <linux/of.h>
13 #include <linux/of_address.h>
14 #include <asm/mach/irq.h>
15 #include <asm/exception.h>
16 
17 #include "common.h"
18 #include "hardware.h"
19 #include "irq-common.h"
20 
21 #define AVIC_INTCNTL		0x00	/* int control reg */
22 #define AVIC_NIMASK		0x04	/* int mask reg */
23 #define AVIC_INTENNUM		0x08	/* int enable number reg */
24 #define AVIC_INTDISNUM		0x0C	/* int disable number reg */
25 #define AVIC_INTENABLEH		0x10	/* int enable reg high */
26 #define AVIC_INTENABLEL		0x14	/* int enable reg low */
27 #define AVIC_INTTYPEH		0x18	/* int type reg high */
28 #define AVIC_INTTYPEL		0x1C	/* int type reg low */
29 #define AVIC_NIPRIORITY(x)	(0x20 + 4 * (7 - (x))) /* int priority */
30 #define AVIC_NIVECSR		0x40	/* norm int vector/status */
31 #define AVIC_FIVECSR		0x44	/* fast int vector/status */
32 #define AVIC_INTSRCH		0x48	/* int source reg high */
33 #define AVIC_INTSRCL		0x4C	/* int source reg low */
34 #define AVIC_INTFRCH		0x50	/* int force reg high */
35 #define AVIC_INTFRCL		0x54	/* int force reg low */
36 #define AVIC_NIPNDH		0x58	/* norm int pending high */
37 #define AVIC_NIPNDL		0x5C	/* norm int pending low */
38 #define AVIC_FIPNDH		0x60	/* fast int pending high */
39 #define AVIC_FIPNDL		0x64	/* fast int pending low */
40 
41 #define AVIC_NUM_IRQS 64
42 
43 /* low power interrupt mask registers */
44 #define MX25_CCM_LPIMR0	0x68
45 #define MX25_CCM_LPIMR1	0x6C
46 
47 static void __iomem *avic_base;
48 static void __iomem *mx25_ccm_base;
49 static struct irq_domain *domain;
50 
51 #ifdef CONFIG_FIQ
52 static int avic_set_irq_fiq(unsigned int hwirq, unsigned int type)
53 {
54 	unsigned int irqt;
55 
56 	if (hwirq >= AVIC_NUM_IRQS)
57 		return -EINVAL;
58 
59 	if (hwirq < AVIC_NUM_IRQS / 2) {
60 		irqt = imx_readl(avic_base + AVIC_INTTYPEL) & ~(1 << hwirq);
61 		imx_writel(irqt | (!!type << hwirq), avic_base + AVIC_INTTYPEL);
62 	} else {
63 		hwirq -= AVIC_NUM_IRQS / 2;
64 		irqt = imx_readl(avic_base + AVIC_INTTYPEH) & ~(1 << hwirq);
65 		imx_writel(irqt | (!!type << hwirq), avic_base + AVIC_INTTYPEH);
66 	}
67 
68 	return 0;
69 }
70 #endif /* CONFIG_FIQ */
71 
72 
73 static struct mxc_extra_irq avic_extra_irq = {
74 #ifdef CONFIG_FIQ
75 	.set_irq_fiq = avic_set_irq_fiq,
76 #endif
77 };
78 
79 #ifdef CONFIG_PM
80 static u32 avic_saved_mask_reg[2];
81 
82 static void avic_irq_suspend(struct irq_data *d)
83 {
84 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
85 	struct irq_chip_type *ct = gc->chip_types;
86 	int idx = d->hwirq >> 5;
87 
88 	avic_saved_mask_reg[idx] = imx_readl(avic_base + ct->regs.mask);
89 	imx_writel(gc->wake_active, avic_base + ct->regs.mask);
90 
91 	if (mx25_ccm_base) {
92 		u8 offs = d->hwirq < AVIC_NUM_IRQS / 2 ?
93 			MX25_CCM_LPIMR0 : MX25_CCM_LPIMR1;
94 		/*
95 		 * The interrupts which are still enabled will be used as wakeup
96 		 * sources. Allow those interrupts in low-power mode.
97 		 * The LPIMR registers use 0 to allow an interrupt, the AVIC
98 		 * registers use 1.
99 		 */
100 		imx_writel(~gc->wake_active, mx25_ccm_base + offs);
101 	}
102 }
103 
104 static void avic_irq_resume(struct irq_data *d)
105 {
106 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
107 	struct irq_chip_type *ct = gc->chip_types;
108 	int idx = d->hwirq >> 5;
109 
110 	imx_writel(avic_saved_mask_reg[idx], avic_base + ct->regs.mask);
111 
112 	if (mx25_ccm_base) {
113 		u8 offs = d->hwirq < AVIC_NUM_IRQS / 2 ?
114 			MX25_CCM_LPIMR0 : MX25_CCM_LPIMR1;
115 
116 		imx_writel(0xffffffff, mx25_ccm_base + offs);
117 	}
118 }
119 
120 #else
121 #define avic_irq_suspend NULL
122 #define avic_irq_resume NULL
123 #endif
124 
125 static __init void avic_init_gc(int idx, unsigned int irq_start)
126 {
127 	struct irq_chip_generic *gc;
128 	struct irq_chip_type *ct;
129 
130 	gc = irq_alloc_generic_chip("mxc-avic", 1, irq_start, avic_base,
131 				    handle_level_irq);
132 	gc->private = &avic_extra_irq;
133 	gc->wake_enabled = IRQ_MSK(32);
134 
135 	ct = gc->chip_types;
136 	ct->chip.irq_mask = irq_gc_mask_clr_bit;
137 	ct->chip.irq_unmask = irq_gc_mask_set_bit;
138 	ct->chip.irq_ack = irq_gc_mask_clr_bit;
139 	ct->chip.irq_set_wake = irq_gc_set_wake;
140 	ct->chip.irq_suspend = avic_irq_suspend;
141 	ct->chip.irq_resume = avic_irq_resume;
142 	ct->regs.mask = !idx ? AVIC_INTENABLEL : AVIC_INTENABLEH;
143 	ct->regs.ack = ct->regs.mask;
144 
145 	irq_setup_generic_chip(gc, IRQ_MSK(32), 0, IRQ_NOREQUEST, 0);
146 }
147 
148 static void __exception_irq_entry avic_handle_irq(struct pt_regs *regs)
149 {
150 	u32 nivector;
151 
152 	do {
153 		nivector = imx_readl(avic_base + AVIC_NIVECSR) >> 16;
154 		if (nivector == 0xffff)
155 			break;
156 
157 		handle_domain_irq(domain, nivector, regs);
158 	} while (1);
159 }
160 
161 /*
162  * This function initializes the AVIC hardware and disables all the
163  * interrupts. It registers the interrupt enable and disable functions
164  * to the kernel for each interrupt source.
165  */
166 static void __init mxc_init_irq(void __iomem *irqbase)
167 {
168 	struct device_node *np;
169 	int irq_base;
170 	int i;
171 
172 	avic_base = irqbase;
173 
174 	np = of_find_compatible_node(NULL, NULL, "fsl,imx25-ccm");
175 	mx25_ccm_base = of_iomap(np, 0);
176 
177 	if (mx25_ccm_base) {
178 		/*
179 		 * By default, we mask all interrupts. We set the actual mask
180 		 * before we go into low-power mode.
181 		 */
182 		imx_writel(0xffffffff, mx25_ccm_base + MX25_CCM_LPIMR0);
183 		imx_writel(0xffffffff, mx25_ccm_base + MX25_CCM_LPIMR1);
184 	}
185 
186 	/* put the AVIC into the reset value with
187 	 * all interrupts disabled
188 	 */
189 	imx_writel(0, avic_base + AVIC_INTCNTL);
190 	imx_writel(0x1f, avic_base + AVIC_NIMASK);
191 
192 	/* disable all interrupts */
193 	imx_writel(0, avic_base + AVIC_INTENABLEH);
194 	imx_writel(0, avic_base + AVIC_INTENABLEL);
195 
196 	/* all IRQ no FIQ */
197 	imx_writel(0, avic_base + AVIC_INTTYPEH);
198 	imx_writel(0, avic_base + AVIC_INTTYPEL);
199 
200 	irq_base = irq_alloc_descs(-1, 0, AVIC_NUM_IRQS, numa_node_id());
201 	WARN_ON(irq_base < 0);
202 
203 	np = of_find_compatible_node(NULL, NULL, "fsl,avic");
204 	domain = irq_domain_add_legacy(np, AVIC_NUM_IRQS, irq_base, 0,
205 				       &irq_domain_simple_ops, NULL);
206 	WARN_ON(!domain);
207 
208 	for (i = 0; i < AVIC_NUM_IRQS / 32; i++, irq_base += 32)
209 		avic_init_gc(i, irq_base);
210 
211 	/* Set default priority value (0) for all IRQ's */
212 	for (i = 0; i < 8; i++)
213 		imx_writel(0, avic_base + AVIC_NIPRIORITY(i));
214 
215 	set_handle_irq(avic_handle_irq);
216 
217 #ifdef CONFIG_FIQ
218 	/* Initialize FIQ */
219 	init_FIQ(FIQ_START);
220 #endif
221 
222 	printk(KERN_INFO "MXC IRQ initialized\n");
223 }
224 
225 static int __init imx_avic_init(struct device_node *node,
226 			       struct device_node *parent)
227 {
228 	void __iomem *avic_base;
229 
230 	avic_base = of_iomap(node, 0);
231 	BUG_ON(!avic_base);
232 	mxc_init_irq(avic_base);
233 	return 0;
234 }
235 
236 IRQCHIP_DECLARE(imx_avic, "fsl,avic", imx_avic_init);
237