xref: /openbmc/linux/arch/arm/mach-imx/avic.c (revision 5d331b7f)
1 /*
2  * Copyright 2004-2007 Freescale Semiconductor, Inc. All Rights Reserved.
3  * Copyright 2008 Juergen Beisert, kernel@pengutronix.de
4  *
5  * This program is free software; you can redistribute it and/or
6  * modify it under the terms of the GNU General Public License
7  * as published by the Free Software Foundation; either version 2
8  * of the License, or (at your option) any later version.
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software
16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
17  * MA  02110-1301, USA.
18  */
19 
20 #include <linux/module.h>
21 #include <linux/irq.h>
22 #include <linux/irqdomain.h>
23 #include <linux/io.h>
24 #include <linux/of.h>
25 #include <linux/of_address.h>
26 #include <asm/mach/irq.h>
27 #include <asm/exception.h>
28 
29 #include "common.h"
30 #include "hardware.h"
31 #include "irq-common.h"
32 
33 #define AVIC_INTCNTL		0x00	/* int control reg */
34 #define AVIC_NIMASK		0x04	/* int mask reg */
35 #define AVIC_INTENNUM		0x08	/* int enable number reg */
36 #define AVIC_INTDISNUM		0x0C	/* int disable number reg */
37 #define AVIC_INTENABLEH		0x10	/* int enable reg high */
38 #define AVIC_INTENABLEL		0x14	/* int enable reg low */
39 #define AVIC_INTTYPEH		0x18	/* int type reg high */
40 #define AVIC_INTTYPEL		0x1C	/* int type reg low */
41 #define AVIC_NIPRIORITY(x)	(0x20 + 4 * (7 - (x))) /* int priority */
42 #define AVIC_NIVECSR		0x40	/* norm int vector/status */
43 #define AVIC_FIVECSR		0x44	/* fast int vector/status */
44 #define AVIC_INTSRCH		0x48	/* int source reg high */
45 #define AVIC_INTSRCL		0x4C	/* int source reg low */
46 #define AVIC_INTFRCH		0x50	/* int force reg high */
47 #define AVIC_INTFRCL		0x54	/* int force reg low */
48 #define AVIC_NIPNDH		0x58	/* norm int pending high */
49 #define AVIC_NIPNDL		0x5C	/* norm int pending low */
50 #define AVIC_FIPNDH		0x60	/* fast int pending high */
51 #define AVIC_FIPNDL		0x64	/* fast int pending low */
52 
53 #define AVIC_NUM_IRQS 64
54 
55 /* low power interrupt mask registers */
56 #define MX25_CCM_LPIMR0	0x68
57 #define MX25_CCM_LPIMR1	0x6C
58 
59 static void __iomem *avic_base;
60 static void __iomem *mx25_ccm_base;
61 static struct irq_domain *domain;
62 
63 #ifdef CONFIG_FIQ
64 static int avic_set_irq_fiq(unsigned int hwirq, unsigned int type)
65 {
66 	unsigned int irqt;
67 
68 	if (hwirq >= AVIC_NUM_IRQS)
69 		return -EINVAL;
70 
71 	if (hwirq < AVIC_NUM_IRQS / 2) {
72 		irqt = imx_readl(avic_base + AVIC_INTTYPEL) & ~(1 << hwirq);
73 		imx_writel(irqt | (!!type << hwirq), avic_base + AVIC_INTTYPEL);
74 	} else {
75 		hwirq -= AVIC_NUM_IRQS / 2;
76 		irqt = imx_readl(avic_base + AVIC_INTTYPEH) & ~(1 << hwirq);
77 		imx_writel(irqt | (!!type << hwirq), avic_base + AVIC_INTTYPEH);
78 	}
79 
80 	return 0;
81 }
82 #endif /* CONFIG_FIQ */
83 
84 
85 static struct mxc_extra_irq avic_extra_irq = {
86 #ifdef CONFIG_FIQ
87 	.set_irq_fiq = avic_set_irq_fiq,
88 #endif
89 };
90 
91 #ifdef CONFIG_PM
92 static u32 avic_saved_mask_reg[2];
93 
94 static void avic_irq_suspend(struct irq_data *d)
95 {
96 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
97 	struct irq_chip_type *ct = gc->chip_types;
98 	int idx = d->hwirq >> 5;
99 
100 	avic_saved_mask_reg[idx] = imx_readl(avic_base + ct->regs.mask);
101 	imx_writel(gc->wake_active, avic_base + ct->regs.mask);
102 
103 	if (mx25_ccm_base) {
104 		u8 offs = d->hwirq < AVIC_NUM_IRQS / 2 ?
105 			MX25_CCM_LPIMR0 : MX25_CCM_LPIMR1;
106 		/*
107 		 * The interrupts which are still enabled will be used as wakeup
108 		 * sources. Allow those interrupts in low-power mode.
109 		 * The LPIMR registers use 0 to allow an interrupt, the AVIC
110 		 * registers use 1.
111 		 */
112 		imx_writel(~gc->wake_active, mx25_ccm_base + offs);
113 	}
114 }
115 
116 static void avic_irq_resume(struct irq_data *d)
117 {
118 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
119 	struct irq_chip_type *ct = gc->chip_types;
120 	int idx = d->hwirq >> 5;
121 
122 	imx_writel(avic_saved_mask_reg[idx], avic_base + ct->regs.mask);
123 
124 	if (mx25_ccm_base) {
125 		u8 offs = d->hwirq < AVIC_NUM_IRQS / 2 ?
126 			MX25_CCM_LPIMR0 : MX25_CCM_LPIMR1;
127 
128 		imx_writel(0xffffffff, mx25_ccm_base + offs);
129 	}
130 }
131 
132 #else
133 #define avic_irq_suspend NULL
134 #define avic_irq_resume NULL
135 #endif
136 
137 static __init void avic_init_gc(int idx, unsigned int irq_start)
138 {
139 	struct irq_chip_generic *gc;
140 	struct irq_chip_type *ct;
141 
142 	gc = irq_alloc_generic_chip("mxc-avic", 1, irq_start, avic_base,
143 				    handle_level_irq);
144 	gc->private = &avic_extra_irq;
145 	gc->wake_enabled = IRQ_MSK(32);
146 
147 	ct = gc->chip_types;
148 	ct->chip.irq_mask = irq_gc_mask_clr_bit;
149 	ct->chip.irq_unmask = irq_gc_mask_set_bit;
150 	ct->chip.irq_ack = irq_gc_mask_clr_bit;
151 	ct->chip.irq_set_wake = irq_gc_set_wake;
152 	ct->chip.irq_suspend = avic_irq_suspend;
153 	ct->chip.irq_resume = avic_irq_resume;
154 	ct->regs.mask = !idx ? AVIC_INTENABLEL : AVIC_INTENABLEH;
155 	ct->regs.ack = ct->regs.mask;
156 
157 	irq_setup_generic_chip(gc, IRQ_MSK(32), 0, IRQ_NOREQUEST, 0);
158 }
159 
160 static void __exception_irq_entry avic_handle_irq(struct pt_regs *regs)
161 {
162 	u32 nivector;
163 
164 	do {
165 		nivector = imx_readl(avic_base + AVIC_NIVECSR) >> 16;
166 		if (nivector == 0xffff)
167 			break;
168 
169 		handle_domain_irq(domain, nivector, regs);
170 	} while (1);
171 }
172 
173 /*
174  * This function initializes the AVIC hardware and disables all the
175  * interrupts. It registers the interrupt enable and disable functions
176  * to the kernel for each interrupt source.
177  */
178 void __init mxc_init_irq(void __iomem *irqbase)
179 {
180 	struct device_node *np;
181 	int irq_base;
182 	int i;
183 
184 	avic_base = irqbase;
185 
186 	np = of_find_compatible_node(NULL, NULL, "fsl,imx25-ccm");
187 	mx25_ccm_base = of_iomap(np, 0);
188 
189 	if (mx25_ccm_base) {
190 		/*
191 		 * By default, we mask all interrupts. We set the actual mask
192 		 * before we go into low-power mode.
193 		 */
194 		imx_writel(0xffffffff, mx25_ccm_base + MX25_CCM_LPIMR0);
195 		imx_writel(0xffffffff, mx25_ccm_base + MX25_CCM_LPIMR1);
196 	}
197 
198 	/* put the AVIC into the reset value with
199 	 * all interrupts disabled
200 	 */
201 	imx_writel(0, avic_base + AVIC_INTCNTL);
202 	imx_writel(0x1f, avic_base + AVIC_NIMASK);
203 
204 	/* disable all interrupts */
205 	imx_writel(0, avic_base + AVIC_INTENABLEH);
206 	imx_writel(0, avic_base + AVIC_INTENABLEL);
207 
208 	/* all IRQ no FIQ */
209 	imx_writel(0, avic_base + AVIC_INTTYPEH);
210 	imx_writel(0, avic_base + AVIC_INTTYPEL);
211 
212 	irq_base = irq_alloc_descs(-1, 0, AVIC_NUM_IRQS, numa_node_id());
213 	WARN_ON(irq_base < 0);
214 
215 	np = of_find_compatible_node(NULL, NULL, "fsl,avic");
216 	domain = irq_domain_add_legacy(np, AVIC_NUM_IRQS, irq_base, 0,
217 				       &irq_domain_simple_ops, NULL);
218 	WARN_ON(!domain);
219 
220 	for (i = 0; i < AVIC_NUM_IRQS / 32; i++, irq_base += 32)
221 		avic_init_gc(i, irq_base);
222 
223 	/* Set default priority value (0) for all IRQ's */
224 	for (i = 0; i < 8; i++)
225 		imx_writel(0, avic_base + AVIC_NIPRIORITY(i));
226 
227 	set_handle_irq(avic_handle_irq);
228 
229 #ifdef CONFIG_FIQ
230 	/* Initialize FIQ */
231 	init_FIQ(FIQ_START);
232 #endif
233 
234 	printk(KERN_INFO "MXC IRQ initialized\n");
235 }
236