summaryrefslogtreecommitdiffstats
path: root/arch/arm/mach-ux500/pm.c
blob: 2cb587b50905af29edbfb914a61ad4e4c9615035 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
/*
 * Copyright (C) ST-Ericsson SA 2010-2013
 * Author: Rickard Andersson <rickard.andersson@stericsson.com> for
 *         ST-Ericsson.
 * Author: Daniel Lezcano <daniel.lezcano@linaro.org> for Linaro.
 * Author: Ulf Hansson <ulf.hansson@linaro.org> for Linaro.
 *
 * License terms: GNU General Public License (GPL) version 2
 *
 */

#include <linux/kernel.h>
#include <linux/irqchip/arm-gic.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/suspend.h>
#include <linux/platform_data/arm-ux500-pm.h>

#include "db8500-regs.h"
#include "pm_domains.h"

/* ARM WFI Standby signal register */
#define PRCM_ARM_WFI_STANDBY    (prcmu_base + 0x130)
#define PRCM_ARM_WFI_STANDBY_WFI0		0x08
#define PRCM_ARM_WFI_STANDBY_WFI1		0x10
#define PRCM_IOCR		(prcmu_base + 0x310)
#define PRCM_IOCR_IOFORCE			0x1

/* Dual A9 core interrupt management unit registers */
#define PRCM_A9_MASK_REQ	(prcmu_base + 0x328)
#define PRCM_A9_MASK_REQ_PRCM_A9_MASK_REQ	0x1

#define PRCM_A9_MASK_ACK	(prcmu_base + 0x32c)
#define PRCM_ARMITMSK31TO0	(prcmu_base + 0x11c)
#define PRCM_ARMITMSK63TO32	(prcmu_base + 0x120)
#define PRCM_ARMITMSK95TO64	(prcmu_base + 0x124)
#define PRCM_ARMITMSK127TO96	(prcmu_base + 0x128)
#define PRCM_POWER_STATE_VAL	(prcmu_base + 0x25C)
#define PRCM_ARMITVAL31TO0	(prcmu_base + 0x260)
#define PRCM_ARMITVAL63TO32	(prcmu_base + 0x264)
#define PRCM_ARMITVAL95TO64	(prcmu_base + 0x268)
#define PRCM_ARMITVAL127TO96	(prcmu_base + 0x26C)

static void __iomem *prcmu_base;

/* This function decouple the gic from the prcmu */
int prcmu_gic_decouple(void)
{
	u32 val = readl(PRCM_A9_MASK_REQ);

	/* Set bit 0 register value to 1 */
	writel(val | PRCM_A9_MASK_REQ_PRCM_A9_MASK_REQ,
	       PRCM_A9_MASK_REQ);

	/* Make sure the register is updated */
	readl(PRCM_A9_MASK_REQ);

	/* Wait a few cycles for the gic mask completion */
	udelay(1);

	return 0;
}

/* This function recouple the gic with the prcmu */
int prcmu_gic_recouple(void)
{
	u32 val = readl(PRCM_A9_MASK_REQ);

	/* Set bit 0 register value to 0 */
	writel(val & ~PRCM_A9_MASK_REQ_PRCM_A9_MASK_REQ, PRCM_A9_MASK_REQ);

	return 0;
}

#define PRCMU_GIC_NUMBER_REGS 5

/*
 * This function checks if there are pending irq on the gic. It only
 * makes sense if the gic has been decoupled before with the
 * db8500_prcmu_gic_decouple function. Disabling an interrupt only
 * disables the forwarding of the interrupt to any CPU interface. It
 * does not prevent the interrupt from changing state, for example
 * becoming pending, or active and pending if it is already
 * active. Hence, we have to check the interrupt is pending *and* is
 * active.
 */
bool prcmu_gic_pending_irq(void)
{
	u32 pr; /* Pending register */
	u32 er; /* Enable register */
	void __iomem *dist_base = __io_address(U8500_GIC_DIST_BASE);
	int i;

	/* 5 registers. STI & PPI not skipped */
	for (i = 0; i < PRCMU_GIC_NUMBER_REGS; i++) {

		pr = readl_relaxed(dist_base + GIC_DIST_PENDING_SET + i * 4);
		er = readl_relaxed(dist_base + GIC_DIST_ENABLE_SET + i * 4);

		if (pr & er)
			return true; /* There is a pending interrupt */
	}

	return false;
}

/*
 * This function checks if there are pending interrupt on the
 * prcmu which has been delegated to monitor the irqs with the
 * db8500_prcmu_copy_gic_settings function.
 */
bool prcmu_pending_irq(void)
{
	u32 it, im;
	int i;

	for (i = 0; i < PRCMU_GIC_NUMBER_REGS - 1; i++) {
		it = readl(PRCM_ARMITVAL31TO0 + i * 4);
		im = readl(PRCM_ARMITMSK31TO0 + i * 4);
		if (it & im)
			return true; /* There is a pending interrupt */
	}

	return false;
}

/*
 * This function checks if the specified cpu is in in WFI. It's usage
 * makes sense only if the gic is decoupled with the db8500_prcmu_gic_decouple
 * function. Of course passing smp_processor_id() to this function will
 * always return false...
 */
bool prcmu_is_cpu_in_wfi(int cpu)
{
	return readl(PRCM_ARM_WFI_STANDBY) & cpu ? PRCM_ARM_WFI_STANDBY_WFI1 :
		     PRCM_ARM_WFI_STANDBY_WFI0;
}

/*
 * This function copies the gic SPI settings to the prcmu in order to
 * monitor them and abort/finish the retention/off sequence or state.
 */
int prcmu_copy_gic_settings(void)
{
	u32 er; /* Enable register */
	void __iomem *dist_base = __io_address(U8500_GIC_DIST_BASE);
	int i;

	/* We skip the STI and PPI */
	for (i = 0; i < PRCMU_GIC_NUMBER_REGS - 1; i++) {
		er = readl_relaxed(dist_base +
				   GIC_DIST_ENABLE_SET + (i + 1) * 4);
		writel(er, PRCM_ARMITMSK31TO0 + i * 4);
	}

	return 0;
}

#ifdef CONFIG_SUSPEND
static int ux500_suspend_enter(suspend_state_t state)
{
	cpu_do_idle();
	return 0;
}

static int ux500_suspend_valid(suspend_state_t state)
{
	return state == PM_SUSPEND_MEM || state == PM_SUSPEND_STANDBY;
}

static const struct platform_suspend_ops ux500_suspend_ops = {
	.enter	      = ux500_suspend_enter,
	.valid	      = ux500_suspend_valid,
};
#define UX500_SUSPEND_OPS	(&ux500_suspend_ops)
#else
#define UX500_SUSPEND_OPS	NULL
#endif

void __init ux500_pm_init(u32 phy_base, u32 size)
{
	prcmu_base = ioremap(phy_base, size);
	if (!prcmu_base) {
		pr_err("could not remap PRCMU for PM functions\n");
		return;
	}
	/*
	 * On watchdog reboot the GIC is in some cases decoupled.
	 * This will make sure that the GIC is correctly configured.
	 */
	prcmu_gic_recouple();

	/* Set up ux500 suspend callbacks. */
	suspend_set_ops(UX500_SUSPEND_OPS);

	/* Initialize ux500 power domains */
	ux500_pm_domains_init();
}