xref: /openbmc/linux/arch/arm/mach-tegra/pm.c (revision 12eb4683)
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 "pm.h"
41 #include "pmc.h"
42 #include "sleep.h"
43 
44 #ifdef CONFIG_PM_SLEEP
45 static DEFINE_SPINLOCK(tegra_lp2_lock);
46 static u32 iram_save_size;
47 static void *iram_save_addr;
48 struct tegra_lp1_iram tegra_lp1_iram;
49 void (*tegra_tear_down_cpu)(void);
50 void (*tegra_sleep_core_finish)(unsigned long v2p);
51 static int (*tegra_sleep_func)(unsigned long v2p);
52 
53 static void tegra_tear_down_cpu_init(void)
54 {
55 	switch (tegra_chip_id) {
56 	case TEGRA20:
57 		if (IS_ENABLED(CONFIG_ARCH_TEGRA_2x_SOC))
58 			tegra_tear_down_cpu = tegra20_tear_down_cpu;
59 		break;
60 	case TEGRA30:
61 	case TEGRA114:
62 	case TEGRA124:
63 		if (IS_ENABLED(CONFIG_ARCH_TEGRA_3x_SOC) ||
64 		    IS_ENABLED(CONFIG_ARCH_TEGRA_114_SOC) ||
65 		    IS_ENABLED(CONFIG_ARCH_TEGRA_124_SOC))
66 			tegra_tear_down_cpu = tegra30_tear_down_cpu;
67 		break;
68 	}
69 }
70 
71 /*
72  * restore_cpu_complex
73  *
74  * restores cpu clock setting, clears flow controller
75  *
76  * Always called on CPU 0.
77  */
78 static void restore_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 	/* Restore the CPU clock settings */
89 	tegra_cpu_clock_resume();
90 
91 	flowctrl_cpu_suspend_exit(cpu);
92 }
93 
94 /*
95  * suspend_cpu_complex
96  *
97  * saves pll state for use by restart_plls, prepares flow controller for
98  * transition to suspend state
99  *
100  * Must always be called on cpu 0.
101  */
102 static void suspend_cpu_complex(void)
103 {
104 	int cpu = smp_processor_id();
105 
106 	BUG_ON(cpu != 0);
107 
108 #ifdef CONFIG_SMP
109 	cpu = cpu_logical_map(cpu);
110 #endif
111 
112 	/* Save the CPU clock settings */
113 	tegra_cpu_clock_suspend();
114 
115 	flowctrl_cpu_suspend_enter(cpu);
116 }
117 
118 void tegra_clear_cpu_in_lp2(void)
119 {
120 	int phy_cpu_id = cpu_logical_map(smp_processor_id());
121 	u32 *cpu_in_lp2 = tegra_cpu_lp2_mask;
122 
123 	spin_lock(&tegra_lp2_lock);
124 
125 	BUG_ON(!(*cpu_in_lp2 & BIT(phy_cpu_id)));
126 	*cpu_in_lp2 &= ~BIT(phy_cpu_id);
127 
128 	spin_unlock(&tegra_lp2_lock);
129 }
130 
131 bool tegra_set_cpu_in_lp2(void)
132 {
133 	int phy_cpu_id = cpu_logical_map(smp_processor_id());
134 	bool last_cpu = false;
135 	cpumask_t *cpu_lp2_mask = tegra_cpu_lp2_mask;
136 	u32 *cpu_in_lp2 = tegra_cpu_lp2_mask;
137 
138 	spin_lock(&tegra_lp2_lock);
139 
140 	BUG_ON((*cpu_in_lp2 & BIT(phy_cpu_id)));
141 	*cpu_in_lp2 |= BIT(phy_cpu_id);
142 
143 	if ((phy_cpu_id == 0) && cpumask_equal(cpu_lp2_mask, cpu_online_mask))
144 		last_cpu = true;
145 	else if (tegra_chip_id == TEGRA20 && phy_cpu_id == 1)
146 		tegra20_cpu_set_resettable_soon();
147 
148 	spin_unlock(&tegra_lp2_lock);
149 	return last_cpu;
150 }
151 
152 int tegra_cpu_do_idle(void)
153 {
154 	return cpu_do_idle();
155 }
156 
157 static int tegra_sleep_cpu(unsigned long v2p)
158 {
159 	setup_mm_for_reboot();
160 	tegra_sleep_cpu_finish(v2p);
161 
162 	/* should never here */
163 	BUG();
164 
165 	return 0;
166 }
167 
168 void tegra_idle_lp2_last(void)
169 {
170 	tegra_pmc_pm_set(TEGRA_SUSPEND_LP2);
171 
172 	cpu_cluster_pm_enter();
173 	suspend_cpu_complex();
174 
175 	cpu_suspend(PHYS_OFFSET - PAGE_OFFSET, &tegra_sleep_cpu);
176 
177 	restore_cpu_complex();
178 	cpu_cluster_pm_exit();
179 }
180 
181 enum tegra_suspend_mode tegra_pm_validate_suspend_mode(
182 				enum tegra_suspend_mode mode)
183 {
184 	/*
185 	 * The Tegra devices support suspending to LP1 or lower currently.
186 	 */
187 	if (mode > TEGRA_SUSPEND_LP1)
188 		return TEGRA_SUSPEND_LP1;
189 
190 	return mode;
191 }
192 
193 static int tegra_sleep_core(unsigned long v2p)
194 {
195 	setup_mm_for_reboot();
196 	tegra_sleep_core_finish(v2p);
197 
198 	/* should never here */
199 	BUG();
200 
201 	return 0;
202 }
203 
204 /*
205  * tegra_lp1_iram_hook
206  *
207  * Hooking the address of LP1 reset vector and SDRAM self-refresh code in
208  * SDRAM. These codes not be copied to IRAM in this fuction. We need to
209  * copy these code to IRAM before LP0/LP1 suspend and restore the content
210  * of IRAM after resume.
211  */
212 static bool tegra_lp1_iram_hook(void)
213 {
214 	switch (tegra_chip_id) {
215 	case TEGRA20:
216 		if (IS_ENABLED(CONFIG_ARCH_TEGRA_2x_SOC))
217 			tegra20_lp1_iram_hook();
218 		break;
219 	case TEGRA30:
220 	case TEGRA114:
221 	case TEGRA124:
222 		if (IS_ENABLED(CONFIG_ARCH_TEGRA_3x_SOC) ||
223 		    IS_ENABLED(CONFIG_ARCH_TEGRA_114_SOC) ||
224 		    IS_ENABLED(CONFIG_ARCH_TEGRA_124_SOC))
225 			tegra30_lp1_iram_hook();
226 		break;
227 	default:
228 		break;
229 	}
230 
231 	if (!tegra_lp1_iram.start_addr || !tegra_lp1_iram.end_addr)
232 		return false;
233 
234 	iram_save_size = tegra_lp1_iram.end_addr - tegra_lp1_iram.start_addr;
235 	iram_save_addr = kmalloc(iram_save_size, GFP_KERNEL);
236 	if (!iram_save_addr)
237 		return false;
238 
239 	return true;
240 }
241 
242 static bool tegra_sleep_core_init(void)
243 {
244 	switch (tegra_chip_id) {
245 	case TEGRA20:
246 		if (IS_ENABLED(CONFIG_ARCH_TEGRA_2x_SOC))
247 			tegra20_sleep_core_init();
248 		break;
249 	case TEGRA30:
250 	case TEGRA114:
251 	case TEGRA124:
252 		if (IS_ENABLED(CONFIG_ARCH_TEGRA_3x_SOC) ||
253 		    IS_ENABLED(CONFIG_ARCH_TEGRA_114_SOC) ||
254 		    IS_ENABLED(CONFIG_ARCH_TEGRA_124_SOC))
255 			tegra30_sleep_core_init();
256 		break;
257 	default:
258 		break;
259 	}
260 
261 	if (!tegra_sleep_core_finish)
262 		return false;
263 
264 	return true;
265 }
266 
267 static void tegra_suspend_enter_lp1(void)
268 {
269 	tegra_pmc_suspend();
270 
271 	/* copy the reset vector & SDRAM shutdown code into IRAM */
272 	memcpy(iram_save_addr, IO_ADDRESS(TEGRA_IRAM_LPx_RESUME_AREA),
273 		iram_save_size);
274 	memcpy(IO_ADDRESS(TEGRA_IRAM_LPx_RESUME_AREA),
275 		tegra_lp1_iram.start_addr, iram_save_size);
276 
277 	*((u32 *)tegra_cpu_lp1_mask) = 1;
278 }
279 
280 static void tegra_suspend_exit_lp1(void)
281 {
282 	tegra_pmc_resume();
283 
284 	/* restore IRAM */
285 	memcpy(IO_ADDRESS(TEGRA_IRAM_LPx_RESUME_AREA), iram_save_addr,
286 		iram_save_size);
287 
288 	*(u32 *)tegra_cpu_lp1_mask = 0;
289 }
290 
291 static const char *lp_state[TEGRA_MAX_SUSPEND_MODE] = {
292 	[TEGRA_SUSPEND_NONE] = "none",
293 	[TEGRA_SUSPEND_LP2] = "LP2",
294 	[TEGRA_SUSPEND_LP1] = "LP1",
295 	[TEGRA_SUSPEND_LP0] = "LP0",
296 };
297 
298 static int tegra_suspend_enter(suspend_state_t state)
299 {
300 	enum tegra_suspend_mode mode = tegra_pmc_get_suspend_mode();
301 
302 	if (WARN_ON(mode < TEGRA_SUSPEND_NONE ||
303 		    mode >= TEGRA_MAX_SUSPEND_MODE))
304 		return -EINVAL;
305 
306 	pr_info("Entering suspend state %s\n", lp_state[mode]);
307 
308 	tegra_pmc_pm_set(mode);
309 
310 	local_fiq_disable();
311 
312 	suspend_cpu_complex();
313 	switch (mode) {
314 	case TEGRA_SUSPEND_LP1:
315 		tegra_suspend_enter_lp1();
316 		break;
317 	case TEGRA_SUSPEND_LP2:
318 		tegra_set_cpu_in_lp2();
319 		break;
320 	default:
321 		break;
322 	}
323 
324 	cpu_suspend(PHYS_OFFSET - PAGE_OFFSET, tegra_sleep_func);
325 
326 	switch (mode) {
327 	case TEGRA_SUSPEND_LP1:
328 		tegra_suspend_exit_lp1();
329 		break;
330 	case TEGRA_SUSPEND_LP2:
331 		tegra_clear_cpu_in_lp2();
332 		break;
333 	default:
334 		break;
335 	}
336 	restore_cpu_complex();
337 
338 	local_fiq_enable();
339 
340 	return 0;
341 }
342 
343 static const struct platform_suspend_ops tegra_suspend_ops = {
344 	.valid		= suspend_valid_only_mem,
345 	.enter		= tegra_suspend_enter,
346 };
347 
348 void __init tegra_init_suspend(void)
349 {
350 	enum tegra_suspend_mode mode = tegra_pmc_get_suspend_mode();
351 
352 	if (mode == TEGRA_SUSPEND_NONE)
353 		return;
354 
355 	tegra_tear_down_cpu_init();
356 	tegra_pmc_suspend_init();
357 
358 	if (mode >= TEGRA_SUSPEND_LP1) {
359 		if (!tegra_lp1_iram_hook() || !tegra_sleep_core_init()) {
360 			pr_err("%s: unable to allocate memory for SDRAM"
361 			       "self-refresh -- LP0/LP1 unavailable\n",
362 			       __func__);
363 			tegra_pmc_set_suspend_mode(TEGRA_SUSPEND_LP2);
364 			mode = TEGRA_SUSPEND_LP2;
365 		}
366 	}
367 
368 	/* set up sleep function for cpu_suspend */
369 	switch (mode) {
370 	case TEGRA_SUSPEND_LP1:
371 		tegra_sleep_func = tegra_sleep_core;
372 		break;
373 	case TEGRA_SUSPEND_LP2:
374 		tegra_sleep_func = tegra_sleep_cpu;
375 		break;
376 	default:
377 		break;
378 	}
379 
380 	suspend_set_ops(&tegra_suspend_ops);
381 }
382 #endif
383