1 /*
2 * Copyright (C) ST-Ericsson SA 2010-2013
3 * Author: Rickard Andersson <rickard.andersson@stericsson.com> for
4 * ST-Ericsson.
5 * Author: Daniel Lezcano <daniel.lezcano@linaro.org> for Linaro.
6 * Author: Ulf Hansson <ulf.hansson@linaro.org> for Linaro.
7 *
8 * License terms: GNU General Public License (GPL) version 2
9 *
10 */
11
12 #include <linux/kernel.h>
13 #include <linux/irqchip/arm-gic.h>
14 #include <linux/delay.h>
15 #include <linux/io.h>
16 #include <linux/suspend.h>
17 #include <linux/platform_data/arm-ux500-pm.h>
18 #include <linux/of.h>
19 #include <linux/of_address.h>
20
21 #include "db8500-regs.h"
22 #include "pm_domains.h"
23
24 /* ARM WFI Standby signal register */
25 #define PRCM_ARM_WFI_STANDBY (prcmu_base + 0x130)
26 #define PRCM_ARM_WFI_STANDBY_WFI0 0x08
27 #define PRCM_ARM_WFI_STANDBY_WFI1 0x10
28 #define PRCM_IOCR (prcmu_base + 0x310)
29 #define PRCM_IOCR_IOFORCE 0x1
30
31 /* Dual A9 core interrupt management unit registers */
32 #define PRCM_A9_MASK_REQ (prcmu_base + 0x328)
33 #define PRCM_A9_MASK_REQ_PRCM_A9_MASK_REQ 0x1
34
35 #define PRCM_A9_MASK_ACK (prcmu_base + 0x32c)
36 #define PRCM_ARMITMSK31TO0 (prcmu_base + 0x11c)
37 #define PRCM_ARMITMSK63TO32 (prcmu_base + 0x120)
38 #define PRCM_ARMITMSK95TO64 (prcmu_base + 0x124)
39 #define PRCM_ARMITMSK127TO96 (prcmu_base + 0x128)
40 #define PRCM_POWER_STATE_VAL (prcmu_base + 0x25C)
41 #define PRCM_ARMITVAL31TO0 (prcmu_base + 0x260)
42 #define PRCM_ARMITVAL63TO32 (prcmu_base + 0x264)
43 #define PRCM_ARMITVAL95TO64 (prcmu_base + 0x268)
44 #define PRCM_ARMITVAL127TO96 (prcmu_base + 0x26C)
45
46 static void __iomem *prcmu_base;
47 static void __iomem *dist_base;
48
49 /* This function decouple the gic from the prcmu */
prcmu_gic_decouple(void)50 int prcmu_gic_decouple(void)
51 {
52 u32 val = readl(PRCM_A9_MASK_REQ);
53
54 /* Set bit 0 register value to 1 */
55 writel(val | PRCM_A9_MASK_REQ_PRCM_A9_MASK_REQ,
56 PRCM_A9_MASK_REQ);
57
58 /* Make sure the register is updated */
59 readl(PRCM_A9_MASK_REQ);
60
61 /* Wait a few cycles for the gic mask completion */
62 udelay(1);
63
64 return 0;
65 }
66
67 /* This function recouple the gic with the prcmu */
prcmu_gic_recouple(void)68 int prcmu_gic_recouple(void)
69 {
70 u32 val = readl(PRCM_A9_MASK_REQ);
71
72 /* Set bit 0 register value to 0 */
73 writel(val & ~PRCM_A9_MASK_REQ_PRCM_A9_MASK_REQ, PRCM_A9_MASK_REQ);
74
75 return 0;
76 }
77
78 #define PRCMU_GIC_NUMBER_REGS 5
79
80 /*
81 * This function checks if there are pending irq on the gic. It only
82 * makes sense if the gic has been decoupled before with the
83 * db8500_prcmu_gic_decouple function. Disabling an interrupt only
84 * disables the forwarding of the interrupt to any CPU interface. It
85 * does not prevent the interrupt from changing state, for example
86 * becoming pending, or active and pending if it is already
87 * active. Hence, we have to check the interrupt is pending *and* is
88 * active.
89 */
prcmu_gic_pending_irq(void)90 bool prcmu_gic_pending_irq(void)
91 {
92 u32 pr; /* Pending register */
93 u32 er; /* Enable register */
94 int i;
95
96 /* 5 registers. STI & PPI not skipped */
97 for (i = 0; i < PRCMU_GIC_NUMBER_REGS; i++) {
98
99 pr = readl_relaxed(dist_base + GIC_DIST_PENDING_SET + i * 4);
100 er = readl_relaxed(dist_base + GIC_DIST_ENABLE_SET + i * 4);
101
102 if (pr & er)
103 return true; /* There is a pending interrupt */
104 }
105
106 return false;
107 }
108
109 /*
110 * This function checks if there are pending interrupt on the
111 * prcmu which has been delegated to monitor the irqs with the
112 * db8500_prcmu_copy_gic_settings function.
113 */
prcmu_pending_irq(void)114 bool prcmu_pending_irq(void)
115 {
116 u32 it, im;
117 int i;
118
119 for (i = 0; i < PRCMU_GIC_NUMBER_REGS - 1; i++) {
120 it = readl(PRCM_ARMITVAL31TO0 + i * 4);
121 im = readl(PRCM_ARMITMSK31TO0 + i * 4);
122 if (it & im)
123 return true; /* There is a pending interrupt */
124 }
125
126 return false;
127 }
128
129 /*
130 * This function checks if the specified cpu is in in WFI. It's usage
131 * makes sense only if the gic is decoupled with the db8500_prcmu_gic_decouple
132 * function. Of course passing smp_processor_id() to this function will
133 * always return false...
134 */
prcmu_is_cpu_in_wfi(int cpu)135 bool prcmu_is_cpu_in_wfi(int cpu)
136 {
137 return readl(PRCM_ARM_WFI_STANDBY) &
138 (cpu ? PRCM_ARM_WFI_STANDBY_WFI1 : PRCM_ARM_WFI_STANDBY_WFI0);
139 }
140
141 /*
142 * This function copies the gic SPI settings to the prcmu in order to
143 * monitor them and abort/finish the retention/off sequence or state.
144 */
prcmu_copy_gic_settings(void)145 int prcmu_copy_gic_settings(void)
146 {
147 u32 er; /* Enable register */
148 int i;
149
150 /* We skip the STI and PPI */
151 for (i = 0; i < PRCMU_GIC_NUMBER_REGS - 1; i++) {
152 er = readl_relaxed(dist_base +
153 GIC_DIST_ENABLE_SET + (i + 1) * 4);
154 writel(er, PRCM_ARMITMSK31TO0 + i * 4);
155 }
156
157 return 0;
158 }
159
160 #ifdef CONFIG_SUSPEND
ux500_suspend_enter(suspend_state_t state)161 static int ux500_suspend_enter(suspend_state_t state)
162 {
163 cpu_do_idle();
164 return 0;
165 }
166
ux500_suspend_valid(suspend_state_t state)167 static int ux500_suspend_valid(suspend_state_t state)
168 {
169 return state == PM_SUSPEND_MEM || state == PM_SUSPEND_STANDBY;
170 }
171
172 static const struct platform_suspend_ops ux500_suspend_ops = {
173 .enter = ux500_suspend_enter,
174 .valid = ux500_suspend_valid,
175 };
176 #define UX500_SUSPEND_OPS (&ux500_suspend_ops)
177 #else
178 #define UX500_SUSPEND_OPS NULL
179 #endif
180
ux500_pm_init(u32 phy_base,u32 size)181 void __init ux500_pm_init(u32 phy_base, u32 size)
182 {
183 struct device_node *np;
184
185 prcmu_base = ioremap(phy_base, size);
186 if (!prcmu_base) {
187 pr_err("could not remap PRCMU for PM functions\n");
188 return;
189 }
190 np = of_find_compatible_node(NULL, NULL, "arm,cortex-a9-gic");
191 dist_base = of_iomap(np, 0);
192 of_node_put(np);
193 if (!dist_base) {
194 pr_err("could not remap GIC dist base for PM functions\n");
195 return;
196 }
197
198 /*
199 * On watchdog reboot the GIC is in some cases decoupled.
200 * This will make sure that the GIC is correctly configured.
201 */
202 prcmu_gic_recouple();
203
204 /* Set up ux500 suspend callbacks. */
205 suspend_set_ops(UX500_SUSPEND_OPS);
206
207 /* Initialize ux500 power domains */
208 ux500_pm_domains_init();
209 }
210