xref: /openbmc/linux/arch/arm/mach-tegra/pm.c (revision 80ecbd24)
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 static void tegra_tear_down_cpu_init(void)
48 {
49 	switch (tegra_chip_id) {
50 	case TEGRA20:
51 		if (IS_ENABLED(CONFIG_ARCH_TEGRA_2x_SOC))
52 			tegra_tear_down_cpu = tegra20_tear_down_cpu;
53 		break;
54 	case TEGRA30:
55 		if (IS_ENABLED(CONFIG_ARCH_TEGRA_3x_SOC))
56 			tegra_tear_down_cpu = tegra30_tear_down_cpu;
57 		break;
58 	}
59 }
60 
61 /*
62  * restore_cpu_complex
63  *
64  * restores cpu clock setting, clears flow controller
65  *
66  * Always called on CPU 0.
67  */
68 static void restore_cpu_complex(void)
69 {
70 	int cpu = smp_processor_id();
71 
72 	BUG_ON(cpu != 0);
73 
74 #ifdef CONFIG_SMP
75 	cpu = cpu_logical_map(cpu);
76 #endif
77 
78 	/* Restore the CPU clock settings */
79 	tegra_cpu_clock_resume();
80 
81 	flowctrl_cpu_suspend_exit(cpu);
82 }
83 
84 /*
85  * suspend_cpu_complex
86  *
87  * saves pll state for use by restart_plls, prepares flow controller for
88  * transition to suspend state
89  *
90  * Must always be called on cpu 0.
91  */
92 static void suspend_cpu_complex(void)
93 {
94 	int cpu = smp_processor_id();
95 
96 	BUG_ON(cpu != 0);
97 
98 #ifdef CONFIG_SMP
99 	cpu = cpu_logical_map(cpu);
100 #endif
101 
102 	/* Save the CPU clock settings */
103 	tegra_cpu_clock_suspend();
104 
105 	flowctrl_cpu_suspend_enter(cpu);
106 }
107 
108 void tegra_clear_cpu_in_lp2(void)
109 {
110 	int phy_cpu_id = cpu_logical_map(smp_processor_id());
111 	u32 *cpu_in_lp2 = tegra_cpu_lp2_mask;
112 
113 	spin_lock(&tegra_lp2_lock);
114 
115 	BUG_ON(!(*cpu_in_lp2 & BIT(phy_cpu_id)));
116 	*cpu_in_lp2 &= ~BIT(phy_cpu_id);
117 
118 	spin_unlock(&tegra_lp2_lock);
119 }
120 
121 bool tegra_set_cpu_in_lp2(void)
122 {
123 	int phy_cpu_id = cpu_logical_map(smp_processor_id());
124 	bool last_cpu = false;
125 	cpumask_t *cpu_lp2_mask = tegra_cpu_lp2_mask;
126 	u32 *cpu_in_lp2 = tegra_cpu_lp2_mask;
127 
128 	spin_lock(&tegra_lp2_lock);
129 
130 	BUG_ON((*cpu_in_lp2 & BIT(phy_cpu_id)));
131 	*cpu_in_lp2 |= BIT(phy_cpu_id);
132 
133 	if ((phy_cpu_id == 0) && cpumask_equal(cpu_lp2_mask, cpu_online_mask))
134 		last_cpu = true;
135 	else if (tegra_chip_id == TEGRA20 && phy_cpu_id == 1)
136 		tegra20_cpu_set_resettable_soon();
137 
138 	spin_unlock(&tegra_lp2_lock);
139 	return last_cpu;
140 }
141 
142 int tegra_cpu_do_idle(void)
143 {
144 	return cpu_do_idle();
145 }
146 
147 static int tegra_sleep_cpu(unsigned long v2p)
148 {
149 	setup_mm_for_reboot();
150 	tegra_sleep_cpu_finish(v2p);
151 
152 	/* should never here */
153 	BUG();
154 
155 	return 0;
156 }
157 
158 void tegra_idle_lp2_last(void)
159 {
160 	tegra_pmc_pm_set(TEGRA_SUSPEND_LP2);
161 
162 	cpu_cluster_pm_enter();
163 	suspend_cpu_complex();
164 
165 	cpu_suspend(PHYS_OFFSET - PAGE_OFFSET, &tegra_sleep_cpu);
166 
167 	restore_cpu_complex();
168 	cpu_cluster_pm_exit();
169 }
170 
171 enum tegra_suspend_mode tegra_pm_validate_suspend_mode(
172 				enum tegra_suspend_mode mode)
173 {
174 	/* Tegra114 didn't support any suspending mode yet. */
175 	if (tegra_chip_id == TEGRA114)
176 		return TEGRA_SUSPEND_NONE;
177 
178 	/*
179 	 * The Tegra devices only support suspending to LP2 currently.
180 	 */
181 	if (mode > TEGRA_SUSPEND_LP2)
182 		return TEGRA_SUSPEND_LP2;
183 
184 	return mode;
185 }
186 
187 static const char *lp_state[TEGRA_MAX_SUSPEND_MODE] = {
188 	[TEGRA_SUSPEND_NONE] = "none",
189 	[TEGRA_SUSPEND_LP2] = "LP2",
190 	[TEGRA_SUSPEND_LP1] = "LP1",
191 	[TEGRA_SUSPEND_LP0] = "LP0",
192 };
193 
194 static int tegra_suspend_enter(suspend_state_t state)
195 {
196 	enum tegra_suspend_mode mode = tegra_pmc_get_suspend_mode();
197 
198 	if (WARN_ON(mode < TEGRA_SUSPEND_NONE ||
199 		    mode >= TEGRA_MAX_SUSPEND_MODE))
200 		return -EINVAL;
201 
202 	pr_info("Entering suspend state %s\n", lp_state[mode]);
203 
204 	tegra_pmc_pm_set(mode);
205 
206 	local_fiq_disable();
207 
208 	suspend_cpu_complex();
209 	switch (mode) {
210 	case TEGRA_SUSPEND_LP2:
211 		tegra_set_cpu_in_lp2();
212 		break;
213 	default:
214 		break;
215 	}
216 
217 	cpu_suspend(PHYS_OFFSET - PAGE_OFFSET, &tegra_sleep_cpu);
218 
219 	switch (mode) {
220 	case TEGRA_SUSPEND_LP2:
221 		tegra_clear_cpu_in_lp2();
222 		break;
223 	default:
224 		break;
225 	}
226 	restore_cpu_complex();
227 
228 	local_fiq_enable();
229 
230 	return 0;
231 }
232 
233 static const struct platform_suspend_ops tegra_suspend_ops = {
234 	.valid		= suspend_valid_only_mem,
235 	.enter		= tegra_suspend_enter,
236 };
237 
238 void __init tegra_init_suspend(void)
239 {
240 	if (tegra_pmc_get_suspend_mode() == TEGRA_SUSPEND_NONE)
241 		return;
242 
243 	tegra_tear_down_cpu_init();
244 	tegra_pmc_suspend_init();
245 
246 	suspend_set_ops(&tegra_suspend_ops);
247 }
248 #endif
249