xref: /openbmc/linux/arch/arm/mach-imx/gpc.c (revision 275876e2)
1 /*
2  * Copyright 2011-2013 Freescale Semiconductor, Inc.
3  * Copyright 2011 Linaro Ltd.
4  *
5  * The code contained herein is licensed under the GNU General Public
6  * License. You may obtain a copy of the GNU General Public License
7  * Version 2 or later at the following locations:
8  *
9  * http://www.opensource.org/licenses/gpl-license.html
10  * http://www.gnu.org/copyleft/gpl.html
11  */
12 
13 #include <linux/io.h>
14 #include <linux/irq.h>
15 #include <linux/of.h>
16 #include <linux/of_address.h>
17 #include <linux/of_irq.h>
18 #include <linux/irqchip/arm-gic.h>
19 #include "common.h"
20 
21 #define GPC_IMR1		0x008
22 #define GPC_PGC_CPU_PDN		0x2a0
23 
24 #define IMR_NUM			4
25 
26 static void __iomem *gpc_base;
27 static u32 gpc_wake_irqs[IMR_NUM];
28 static u32 gpc_saved_imrs[IMR_NUM];
29 
30 void imx_gpc_pre_suspend(bool arm_power_off)
31 {
32 	void __iomem *reg_imr1 = gpc_base + GPC_IMR1;
33 	int i;
34 
35 	/* Tell GPC to power off ARM core when suspend */
36 	if (arm_power_off)
37 		writel_relaxed(0x1, gpc_base + GPC_PGC_CPU_PDN);
38 
39 	for (i = 0; i < IMR_NUM; i++) {
40 		gpc_saved_imrs[i] = readl_relaxed(reg_imr1 + i * 4);
41 		writel_relaxed(~gpc_wake_irqs[i], reg_imr1 + i * 4);
42 	}
43 }
44 
45 void imx_gpc_post_resume(void)
46 {
47 	void __iomem *reg_imr1 = gpc_base + GPC_IMR1;
48 	int i;
49 
50 	/* Keep ARM core powered on for other low-power modes */
51 	writel_relaxed(0x0, gpc_base + GPC_PGC_CPU_PDN);
52 
53 	for (i = 0; i < IMR_NUM; i++)
54 		writel_relaxed(gpc_saved_imrs[i], reg_imr1 + i * 4);
55 }
56 
57 static int imx_gpc_irq_set_wake(struct irq_data *d, unsigned int on)
58 {
59 	unsigned int idx = d->irq / 32 - 1;
60 	u32 mask;
61 
62 	/* Sanity check for SPI irq */
63 	if (d->irq < 32)
64 		return -EINVAL;
65 
66 	mask = 1 << d->irq % 32;
67 	gpc_wake_irqs[idx] = on ? gpc_wake_irqs[idx] | mask :
68 				  gpc_wake_irqs[idx] & ~mask;
69 
70 	return 0;
71 }
72 
73 void imx_gpc_mask_all(void)
74 {
75 	void __iomem *reg_imr1 = gpc_base + GPC_IMR1;
76 	int i;
77 
78 	for (i = 0; i < IMR_NUM; i++) {
79 		gpc_saved_imrs[i] = readl_relaxed(reg_imr1 + i * 4);
80 		writel_relaxed(~0, reg_imr1 + i * 4);
81 	}
82 
83 }
84 
85 void imx_gpc_restore_all(void)
86 {
87 	void __iomem *reg_imr1 = gpc_base + GPC_IMR1;
88 	int i;
89 
90 	for (i = 0; i < IMR_NUM; i++)
91 		writel_relaxed(gpc_saved_imrs[i], reg_imr1 + i * 4);
92 }
93 
94 void imx_gpc_irq_unmask(struct irq_data *d)
95 {
96 	void __iomem *reg;
97 	u32 val;
98 
99 	/* Sanity check for SPI irq */
100 	if (d->irq < 32)
101 		return;
102 
103 	reg = gpc_base + GPC_IMR1 + (d->irq / 32 - 1) * 4;
104 	val = readl_relaxed(reg);
105 	val &= ~(1 << d->irq % 32);
106 	writel_relaxed(val, reg);
107 }
108 
109 void imx_gpc_irq_mask(struct irq_data *d)
110 {
111 	void __iomem *reg;
112 	u32 val;
113 
114 	/* Sanity check for SPI irq */
115 	if (d->irq < 32)
116 		return;
117 
118 	reg = gpc_base + GPC_IMR1 + (d->irq / 32 - 1) * 4;
119 	val = readl_relaxed(reg);
120 	val |= 1 << (d->irq % 32);
121 	writel_relaxed(val, reg);
122 }
123 
124 void __init imx_gpc_init(void)
125 {
126 	struct device_node *np;
127 	int i;
128 
129 	np = of_find_compatible_node(NULL, NULL, "fsl,imx6q-gpc");
130 	gpc_base = of_iomap(np, 0);
131 	WARN_ON(!gpc_base);
132 
133 	/* Initially mask all interrupts */
134 	for (i = 0; i < IMR_NUM; i++)
135 		writel_relaxed(~0, gpc_base + GPC_IMR1 + i * 4);
136 
137 	/* Register GPC as the secondary interrupt controller behind GIC */
138 	gic_arch_extn.irq_mask = imx_gpc_irq_mask;
139 	gic_arch_extn.irq_unmask = imx_gpc_irq_unmask;
140 	gic_arch_extn.irq_set_wake = imx_gpc_irq_set_wake;
141 }
142