1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) ST-Ericsson SA 2010-2013
4 * Author: Rickard Andersson <rickard.andersson@stericsson.com> for
5 *         ST-Ericsson.
6 * Author: Daniel Lezcano <daniel.lezcano@linaro.org> for Linaro.
7 * Author: Ulf Hansson <ulf.hansson@linaro.org> for Linaro.
8 */
9
10#include <linux/kernel.h>
11#include <linux/irqchip/arm-gic.h>
12#include <linux/delay.h>
13#include <linux/io.h>
14#include <linux/suspend.h>
15#include <linux/platform_data/arm-ux500-pm.h>
16#include <linux/of.h>
17#include <linux/of_address.h>
18
19/* ARM WFI Standby signal register */
20#define PRCM_ARM_WFI_STANDBY    (prcmu_base + 0x130)
21#define PRCM_ARM_WFI_STANDBY_WFI0		0x08
22#define PRCM_ARM_WFI_STANDBY_WFI1		0x10
23#define PRCM_IOCR		(prcmu_base + 0x310)
24#define PRCM_IOCR_IOFORCE			0x1
25
26/* Dual A9 core interrupt management unit registers */
27#define PRCM_A9_MASK_REQ	(prcmu_base + 0x328)
28#define PRCM_A9_MASK_REQ_PRCM_A9_MASK_REQ	0x1
29
30#define PRCM_A9_MASK_ACK	(prcmu_base + 0x32c)
31#define PRCM_ARMITMSK31TO0	(prcmu_base + 0x11c)
32#define PRCM_ARMITMSK63TO32	(prcmu_base + 0x120)
33#define PRCM_ARMITMSK95TO64	(prcmu_base + 0x124)
34#define PRCM_ARMITMSK127TO96	(prcmu_base + 0x128)
35#define PRCM_POWER_STATE_VAL	(prcmu_base + 0x25C)
36#define PRCM_ARMITVAL31TO0	(prcmu_base + 0x260)
37#define PRCM_ARMITVAL63TO32	(prcmu_base + 0x264)
38#define PRCM_ARMITVAL95TO64	(prcmu_base + 0x268)
39#define PRCM_ARMITVAL127TO96	(prcmu_base + 0x26C)
40
41static void __iomem *prcmu_base;
42static void __iomem *dist_base;
43
44/* This function decouple the gic from the prcmu */
45int prcmu_gic_decouple(void)
46{
47	u32 val = readl(PRCM_A9_MASK_REQ);
48
49	/* Set bit 0 register value to 1 */
50	writel(val | PRCM_A9_MASK_REQ_PRCM_A9_MASK_REQ,
51	       PRCM_A9_MASK_REQ);
52
53	/* Make sure the register is updated */
54	readl(PRCM_A9_MASK_REQ);
55
56	/* Wait a few cycles for the gic mask completion */
57	udelay(1);
58
59	return 0;
60}
61
62/* This function recouple the gic with the prcmu */
63int prcmu_gic_recouple(void)
64{
65	u32 val = readl(PRCM_A9_MASK_REQ);
66
67	/* Set bit 0 register value to 0 */
68	writel(val & ~PRCM_A9_MASK_REQ_PRCM_A9_MASK_REQ, PRCM_A9_MASK_REQ);
69
70	return 0;
71}
72
73#define PRCMU_GIC_NUMBER_REGS 5
74
75/*
76 * This function checks if there are pending irq on the gic. It only
77 * makes sense if the gic has been decoupled before with the
78 * db8500_prcmu_gic_decouple function. Disabling an interrupt only
79 * disables the forwarding of the interrupt to any CPU interface. It
80 * does not prevent the interrupt from changing state, for example
81 * becoming pending, or active and pending if it is already
82 * active. Hence, we have to check the interrupt is pending *and* is
83 * active.
84 */
85bool prcmu_gic_pending_irq(void)
86{
87	u32 pr; /* Pending register */
88	u32 er; /* Enable register */
89	int i;
90
91	/* 5 registers. STI & PPI not skipped */
92	for (i = 0; i < PRCMU_GIC_NUMBER_REGS; i++) {
93
94		pr = readl_relaxed(dist_base + GIC_DIST_PENDING_SET + i * 4);
95		er = readl_relaxed(dist_base + GIC_DIST_ENABLE_SET + i * 4);
96
97		if (pr & er)
98			return true; /* There is a pending interrupt */
99	}
100
101	return false;
102}
103
104/*
105 * This function checks if there are pending interrupt on the
106 * prcmu which has been delegated to monitor the irqs with the
107 * db8500_prcmu_copy_gic_settings function.
108 */
109bool prcmu_pending_irq(void)
110{
111	u32 it, im;
112	int i;
113
114	for (i = 0; i < PRCMU_GIC_NUMBER_REGS - 1; i++) {
115		it = readl(PRCM_ARMITVAL31TO0 + i * 4);
116		im = readl(PRCM_ARMITMSK31TO0 + i * 4);
117		if (it & im)
118			return true; /* There is a pending interrupt */
119	}
120
121	return false;
122}
123
124/*
125 * This function checks if the specified cpu is in WFI. It's usage
126 * makes sense only if the gic is decoupled with the db8500_prcmu_gic_decouple
127 * function. Of course passing smp_processor_id() to this function will
128 * always return false...
129 */
130bool prcmu_is_cpu_in_wfi(int cpu)
131{
132	return readl(PRCM_ARM_WFI_STANDBY) &
133		(cpu ? PRCM_ARM_WFI_STANDBY_WFI1 : PRCM_ARM_WFI_STANDBY_WFI0);
134}
135
136/*
137 * This function copies the gic SPI settings to the prcmu in order to
138 * monitor them and abort/finish the retention/off sequence or state.
139 */
140int prcmu_copy_gic_settings(void)
141{
142	u32 er; /* Enable register */
143	int i;
144
145	/* We skip the STI and PPI */
146	for (i = 0; i < PRCMU_GIC_NUMBER_REGS - 1; i++) {
147		er = readl_relaxed(dist_base +
148				   GIC_DIST_ENABLE_SET + (i + 1) * 4);
149		writel(er, PRCM_ARMITMSK31TO0 + i * 4);
150	}
151
152	return 0;
153}
154
155#ifdef CONFIG_SUSPEND
156static int ux500_suspend_enter(suspend_state_t state)
157{
158	cpu_do_idle();
159	return 0;
160}
161
162static int ux500_suspend_valid(suspend_state_t state)
163{
164	return state == PM_SUSPEND_MEM || state == PM_SUSPEND_STANDBY;
165}
166
167static const struct platform_suspend_ops ux500_suspend_ops = {
168	.enter	      = ux500_suspend_enter,
169	.valid	      = ux500_suspend_valid,
170};
171#define UX500_SUSPEND_OPS	(&ux500_suspend_ops)
172#else
173#define UX500_SUSPEND_OPS	NULL
174#endif
175
176void __init ux500_pm_init(u32 phy_base, u32 size)
177{
178	struct device_node *np;
179
180	prcmu_base = ioremap(phy_base, size);
181	if (!prcmu_base) {
182		pr_err("could not remap PRCMU for PM functions\n");
183		return;
184	}
185	np = of_find_compatible_node(NULL, NULL, "arm,cortex-a9-gic");
186	dist_base = of_iomap(np, 0);
187	of_node_put(np);
188	if (!dist_base) {
189		pr_err("could not remap GIC dist base for PM functions\n");
190		return;
191	}
192
193	/*
194	 * On watchdog reboot the GIC is in some cases decoupled.
195	 * This will make sure that the GIC is correctly configured.
196	 */
197	prcmu_gic_recouple();
198
199	/* Set up ux500 suspend callbacks. */
200	suspend_set_ops(UX500_SUSPEND_OPS);
201}
202