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1 /*
2  * CPU complex suspend & resume functions for Tegra SoCs
3  *
4  * Copyright (c) 2009-2012, NVIDIA Corporation. All rights reserved.
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms and conditions of the GNU General Public License,
8  * version 2, as published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope it will be useful, but WITHOUT
11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
13  * more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
17  */
18 
19 #include <linux/kernel.h>
20 #include <linux/spinlock.h>
21 #include <linux/io.h>
22 #include <linux/cpumask.h>
23 #include <linux/delay.h>
24 #include <linux/cpu_pm.h>
25 #include <linux/suspend.h>
26 #include <linux/err.h>
27 #include <linux/clk/tegra.h>
28 
29 #include <asm/smp_plat.h>
30 #include <asm/cacheflush.h>
31 #include <asm/suspend.h>
32 #include <asm/idmap.h>
33 #include <asm/proc-fns.h>
34 #include <asm/tlbflush.h>
35 
36 #include "iomap.h"
37 #include "reset.h"
38 #include "flowctrl.h"
39 #include "fuse.h"
40 #include "pmc.h"
41 #include "sleep.h"
42 
43 #ifdef CONFIG_PM_SLEEP
44 static DEFINE_SPINLOCK(tegra_lp2_lock);
45 void (*tegra_tear_down_cpu)(void);
46 
47 /*
48  * restore_cpu_complex
49  *
50  * restores cpu clock setting, clears flow controller
51  *
52  * Always called on CPU 0.
53  */
restore_cpu_complex(void)54 static void restore_cpu_complex(void)
55 {
56 	int cpu = smp_processor_id();
57 
58 	BUG_ON(cpu != 0);
59 
60 #ifdef CONFIG_SMP
61 	cpu = cpu_logical_map(cpu);
62 #endif
63 
64 	/* Restore the CPU clock settings */
65 	tegra_cpu_clock_resume();
66 
67 	flowctrl_cpu_suspend_exit(cpu);
68 }
69 
70 /*
71  * suspend_cpu_complex
72  *
73  * saves pll state for use by restart_plls, prepares flow controller for
74  * transition to suspend state
75  *
76  * Must always be called on cpu 0.
77  */
suspend_cpu_complex(void)78 static void suspend_cpu_complex(void)
79 {
80 	int cpu = smp_processor_id();
81 
82 	BUG_ON(cpu != 0);
83 
84 #ifdef CONFIG_SMP
85 	cpu = cpu_logical_map(cpu);
86 #endif
87 
88 	/* Save the CPU clock settings */
89 	tegra_cpu_clock_suspend();
90 
91 	flowctrl_cpu_suspend_enter(cpu);
92 }
93 
tegra_clear_cpu_in_lp2(int phy_cpu_id)94 void tegra_clear_cpu_in_lp2(int phy_cpu_id)
95 {
96 	u32 *cpu_in_lp2 = tegra_cpu_lp2_mask;
97 
98 	spin_lock(&tegra_lp2_lock);
99 
100 	BUG_ON(!(*cpu_in_lp2 & BIT(phy_cpu_id)));
101 	*cpu_in_lp2 &= ~BIT(phy_cpu_id);
102 
103 	spin_unlock(&tegra_lp2_lock);
104 }
105 
tegra_set_cpu_in_lp2(int phy_cpu_id)106 bool tegra_set_cpu_in_lp2(int phy_cpu_id)
107 {
108 	bool last_cpu = false;
109 	cpumask_t *cpu_lp2_mask = tegra_cpu_lp2_mask;
110 	u32 *cpu_in_lp2 = tegra_cpu_lp2_mask;
111 
112 	spin_lock(&tegra_lp2_lock);
113 
114 	BUG_ON((*cpu_in_lp2 & BIT(phy_cpu_id)));
115 	*cpu_in_lp2 |= BIT(phy_cpu_id);
116 
117 	if ((phy_cpu_id == 0) && cpumask_equal(cpu_lp2_mask, cpu_online_mask))
118 		last_cpu = true;
119 	else if (tegra_chip_id == TEGRA20 && phy_cpu_id == 1)
120 		tegra20_cpu_set_resettable_soon();
121 
122 	spin_unlock(&tegra_lp2_lock);
123 	return last_cpu;
124 }
125 
tegra_cpu_do_idle(void)126 int tegra_cpu_do_idle(void)
127 {
128 	return cpu_do_idle();
129 }
130 
tegra_sleep_cpu(unsigned long v2p)131 static int tegra_sleep_cpu(unsigned long v2p)
132 {
133 	setup_mm_for_reboot();
134 	tegra_sleep_cpu_finish(v2p);
135 
136 	/* should never here */
137 	BUG();
138 
139 	return 0;
140 }
141 
tegra_idle_lp2_last(void)142 void tegra_idle_lp2_last(void)
143 {
144 	tegra_pmc_pm_set(TEGRA_SUSPEND_LP2);
145 
146 	cpu_cluster_pm_enter();
147 	suspend_cpu_complex();
148 
149 	cpu_suspend(PHYS_OFFSET - PAGE_OFFSET, &tegra_sleep_cpu);
150 
151 	restore_cpu_complex();
152 	cpu_cluster_pm_exit();
153 }
154 
tegra_pm_validate_suspend_mode(enum tegra_suspend_mode mode)155 enum tegra_suspend_mode tegra_pm_validate_suspend_mode(
156 				enum tegra_suspend_mode mode)
157 {
158 	/* Tegra114 didn't support any suspending mode yet. */
159 	if (tegra_chip_id == TEGRA114)
160 		return TEGRA_SUSPEND_NONE;
161 
162 	/*
163 	 * The Tegra devices only support suspending to LP2 currently.
164 	 */
165 	if (mode > TEGRA_SUSPEND_LP2)
166 		return TEGRA_SUSPEND_LP2;
167 
168 	return mode;
169 }
170 
171 static const char *lp_state[TEGRA_MAX_SUSPEND_MODE] = {
172 	[TEGRA_SUSPEND_NONE] = "none",
173 	[TEGRA_SUSPEND_LP2] = "LP2",
174 	[TEGRA_SUSPEND_LP1] = "LP1",
175 	[TEGRA_SUSPEND_LP0] = "LP0",
176 };
177 
tegra_suspend_enter(suspend_state_t state)178 static int __cpuinit tegra_suspend_enter(suspend_state_t state)
179 {
180 	enum tegra_suspend_mode mode = tegra_pmc_get_suspend_mode();
181 
182 	if (WARN_ON(mode < TEGRA_SUSPEND_NONE ||
183 		    mode >= TEGRA_MAX_SUSPEND_MODE))
184 		return -EINVAL;
185 
186 	pr_info("Entering suspend state %s\n", lp_state[mode]);
187 
188 	tegra_pmc_pm_set(mode);
189 
190 	local_fiq_disable();
191 
192 	suspend_cpu_complex();
193 	switch (mode) {
194 	case TEGRA_SUSPEND_LP2:
195 		tegra_set_cpu_in_lp2(0);
196 		break;
197 	default:
198 		break;
199 	}
200 
201 	cpu_suspend(PHYS_OFFSET - PAGE_OFFSET, &tegra_sleep_cpu);
202 
203 	switch (mode) {
204 	case TEGRA_SUSPEND_LP2:
205 		tegra_clear_cpu_in_lp2(0);
206 		break;
207 	default:
208 		break;
209 	}
210 	restore_cpu_complex();
211 
212 	local_fiq_enable();
213 
214 	return 0;
215 }
216 
217 static const struct platform_suspend_ops tegra_suspend_ops = {
218 	.valid		= suspend_valid_only_mem,
219 	.enter		= tegra_suspend_enter,
220 };
221 
tegra_init_suspend(void)222 void __init tegra_init_suspend(void)
223 {
224 	if (tegra_pmc_get_suspend_mode() == TEGRA_SUSPEND_NONE)
225 		return;
226 
227 	tegra_pmc_suspend_init();
228 
229 	suspend_set_ops(&tegra_suspend_ops);
230 }
231 #endif
232