xref: /openbmc/linux/arch/arm/mach-tegra/pm.c (revision 6d99a79c)
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/clk/tegra.h>
20 #include <linux/cpumask.h>
21 #include <linux/cpu_pm.h>
22 #include <linux/delay.h>
23 #include <linux/err.h>
24 #include <linux/io.h>
25 #include <linux/kernel.h>
26 #include <linux/slab.h>
27 #include <linux/spinlock.h>
28 #include <linux/suspend.h>
29 
30 #include <soc/tegra/flowctrl.h>
31 #include <soc/tegra/fuse.h>
32 #include <soc/tegra/pm.h>
33 #include <soc/tegra/pmc.h>
34 
35 #include <asm/cacheflush.h>
36 #include <asm/idmap.h>
37 #include <asm/proc-fns.h>
38 #include <asm/smp_plat.h>
39 #include <asm/suspend.h>
40 #include <asm/tlbflush.h>
41 
42 #include "iomap.h"
43 #include "pm.h"
44 #include "reset.h"
45 #include "sleep.h"
46 
47 #ifdef CONFIG_PM_SLEEP
48 static DEFINE_SPINLOCK(tegra_lp2_lock);
49 static u32 iram_save_size;
50 static void *iram_save_addr;
51 struct tegra_lp1_iram tegra_lp1_iram;
52 void (*tegra_tear_down_cpu)(void);
53 void (*tegra_sleep_core_finish)(unsigned long v2p);
54 static int (*tegra_sleep_func)(unsigned long v2p);
55 
56 static void tegra_tear_down_cpu_init(void)
57 {
58 	switch (tegra_get_chip_id()) {
59 	case TEGRA20:
60 		if (IS_ENABLED(CONFIG_ARCH_TEGRA_2x_SOC))
61 			tegra_tear_down_cpu = tegra20_tear_down_cpu;
62 		break;
63 	case TEGRA30:
64 	case TEGRA114:
65 	case TEGRA124:
66 		if (IS_ENABLED(CONFIG_ARCH_TEGRA_3x_SOC) ||
67 		    IS_ENABLED(CONFIG_ARCH_TEGRA_114_SOC) ||
68 		    IS_ENABLED(CONFIG_ARCH_TEGRA_124_SOC))
69 			tegra_tear_down_cpu = tegra30_tear_down_cpu;
70 		break;
71 	}
72 }
73 
74 /*
75  * restore_cpu_complex
76  *
77  * restores cpu clock setting, clears flow controller
78  *
79  * Always called on CPU 0.
80  */
81 static void restore_cpu_complex(void)
82 {
83 	int cpu = smp_processor_id();
84 
85 	BUG_ON(cpu != 0);
86 
87 #ifdef CONFIG_SMP
88 	cpu = cpu_logical_map(cpu);
89 #endif
90 
91 	/* Restore the CPU clock settings */
92 	tegra_cpu_clock_resume();
93 
94 	flowctrl_cpu_suspend_exit(cpu);
95 }
96 
97 /*
98  * suspend_cpu_complex
99  *
100  * saves pll state for use by restart_plls, prepares flow controller for
101  * transition to suspend state
102  *
103  * Must always be called on cpu 0.
104  */
105 static void suspend_cpu_complex(void)
106 {
107 	int cpu = smp_processor_id();
108 
109 	BUG_ON(cpu != 0);
110 
111 #ifdef CONFIG_SMP
112 	cpu = cpu_logical_map(cpu);
113 #endif
114 
115 	/* Save the CPU clock settings */
116 	tegra_cpu_clock_suspend();
117 
118 	flowctrl_cpu_suspend_enter(cpu);
119 }
120 
121 void tegra_clear_cpu_in_lp2(void)
122 {
123 	int phy_cpu_id = cpu_logical_map(smp_processor_id());
124 	u32 *cpu_in_lp2 = tegra_cpu_lp2_mask;
125 
126 	spin_lock(&tegra_lp2_lock);
127 
128 	BUG_ON(!(*cpu_in_lp2 & BIT(phy_cpu_id)));
129 	*cpu_in_lp2 &= ~BIT(phy_cpu_id);
130 
131 	spin_unlock(&tegra_lp2_lock);
132 }
133 
134 bool tegra_set_cpu_in_lp2(void)
135 {
136 	int phy_cpu_id = cpu_logical_map(smp_processor_id());
137 	bool last_cpu = false;
138 	cpumask_t *cpu_lp2_mask = tegra_cpu_lp2_mask;
139 	u32 *cpu_in_lp2 = tegra_cpu_lp2_mask;
140 
141 	spin_lock(&tegra_lp2_lock);
142 
143 	BUG_ON((*cpu_in_lp2 & BIT(phy_cpu_id)));
144 	*cpu_in_lp2 |= BIT(phy_cpu_id);
145 
146 	if ((phy_cpu_id == 0) && cpumask_equal(cpu_lp2_mask, cpu_online_mask))
147 		last_cpu = true;
148 	else if (tegra_get_chip_id() == TEGRA20 && phy_cpu_id == 1)
149 		tegra20_cpu_set_resettable_soon();
150 
151 	spin_unlock(&tegra_lp2_lock);
152 	return last_cpu;
153 }
154 
155 int tegra_cpu_do_idle(void)
156 {
157 	return cpu_do_idle();
158 }
159 
160 static int tegra_sleep_cpu(unsigned long v2p)
161 {
162 	setup_mm_for_reboot();
163 	tegra_sleep_cpu_finish(v2p);
164 
165 	/* should never here */
166 	BUG();
167 
168 	return 0;
169 }
170 
171 static void tegra_pm_set(enum tegra_suspend_mode mode)
172 {
173 	u32 value;
174 
175 	switch (tegra_get_chip_id()) {
176 	case TEGRA20:
177 	case TEGRA30:
178 		break;
179 	default:
180 		/* Turn off CRAIL */
181 		value = flowctrl_read_cpu_csr(0);
182 		value &= ~FLOW_CTRL_CSR_ENABLE_EXT_MASK;
183 		value |= FLOW_CTRL_CSR_ENABLE_EXT_CRAIL;
184 		flowctrl_write_cpu_csr(0, value);
185 		break;
186 	}
187 
188 	tegra_pmc_enter_suspend_mode(mode);
189 }
190 
191 void tegra_idle_lp2_last(void)
192 {
193 	tegra_pm_set(TEGRA_SUSPEND_LP2);
194 
195 	cpu_cluster_pm_enter();
196 	suspend_cpu_complex();
197 
198 	cpu_suspend(PHYS_OFFSET - PAGE_OFFSET, &tegra_sleep_cpu);
199 
200 	restore_cpu_complex();
201 	cpu_cluster_pm_exit();
202 }
203 
204 enum tegra_suspend_mode tegra_pm_validate_suspend_mode(
205 				enum tegra_suspend_mode mode)
206 {
207 	/*
208 	 * The Tegra devices support suspending to LP1 or lower currently.
209 	 */
210 	if (mode > TEGRA_SUSPEND_LP1)
211 		return TEGRA_SUSPEND_LP1;
212 
213 	return mode;
214 }
215 
216 static int tegra_sleep_core(unsigned long v2p)
217 {
218 	setup_mm_for_reboot();
219 	tegra_sleep_core_finish(v2p);
220 
221 	/* should never here */
222 	BUG();
223 
224 	return 0;
225 }
226 
227 /*
228  * tegra_lp1_iram_hook
229  *
230  * Hooking the address of LP1 reset vector and SDRAM self-refresh code in
231  * SDRAM. These codes not be copied to IRAM in this fuction. We need to
232  * copy these code to IRAM before LP0/LP1 suspend and restore the content
233  * of IRAM after resume.
234  */
235 static bool tegra_lp1_iram_hook(void)
236 {
237 	switch (tegra_get_chip_id()) {
238 	case TEGRA20:
239 		if (IS_ENABLED(CONFIG_ARCH_TEGRA_2x_SOC))
240 			tegra20_lp1_iram_hook();
241 		break;
242 	case TEGRA30:
243 	case TEGRA114:
244 	case TEGRA124:
245 		if (IS_ENABLED(CONFIG_ARCH_TEGRA_3x_SOC) ||
246 		    IS_ENABLED(CONFIG_ARCH_TEGRA_114_SOC) ||
247 		    IS_ENABLED(CONFIG_ARCH_TEGRA_124_SOC))
248 			tegra30_lp1_iram_hook();
249 		break;
250 	default:
251 		break;
252 	}
253 
254 	if (!tegra_lp1_iram.start_addr || !tegra_lp1_iram.end_addr)
255 		return false;
256 
257 	iram_save_size = tegra_lp1_iram.end_addr - tegra_lp1_iram.start_addr;
258 	iram_save_addr = kmalloc(iram_save_size, GFP_KERNEL);
259 	if (!iram_save_addr)
260 		return false;
261 
262 	return true;
263 }
264 
265 static bool tegra_sleep_core_init(void)
266 {
267 	switch (tegra_get_chip_id()) {
268 	case TEGRA20:
269 		if (IS_ENABLED(CONFIG_ARCH_TEGRA_2x_SOC))
270 			tegra20_sleep_core_init();
271 		break;
272 	case TEGRA30:
273 	case TEGRA114:
274 	case TEGRA124:
275 		if (IS_ENABLED(CONFIG_ARCH_TEGRA_3x_SOC) ||
276 		    IS_ENABLED(CONFIG_ARCH_TEGRA_114_SOC) ||
277 		    IS_ENABLED(CONFIG_ARCH_TEGRA_124_SOC))
278 			tegra30_sleep_core_init();
279 		break;
280 	default:
281 		break;
282 	}
283 
284 	if (!tegra_sleep_core_finish)
285 		return false;
286 
287 	return true;
288 }
289 
290 static void tegra_suspend_enter_lp1(void)
291 {
292 	/* copy the reset vector & SDRAM shutdown code into IRAM */
293 	memcpy(iram_save_addr, IO_ADDRESS(TEGRA_IRAM_LPx_RESUME_AREA),
294 		iram_save_size);
295 	memcpy(IO_ADDRESS(TEGRA_IRAM_LPx_RESUME_AREA),
296 		tegra_lp1_iram.start_addr, iram_save_size);
297 
298 	*((u32 *)tegra_cpu_lp1_mask) = 1;
299 }
300 
301 static void tegra_suspend_exit_lp1(void)
302 {
303 	/* restore IRAM */
304 	memcpy(IO_ADDRESS(TEGRA_IRAM_LPx_RESUME_AREA), iram_save_addr,
305 		iram_save_size);
306 
307 	*(u32 *)tegra_cpu_lp1_mask = 0;
308 }
309 
310 static const char *lp_state[TEGRA_MAX_SUSPEND_MODE] = {
311 	[TEGRA_SUSPEND_NONE] = "none",
312 	[TEGRA_SUSPEND_LP2] = "LP2",
313 	[TEGRA_SUSPEND_LP1] = "LP1",
314 	[TEGRA_SUSPEND_LP0] = "LP0",
315 };
316 
317 static int tegra_suspend_enter(suspend_state_t state)
318 {
319 	enum tegra_suspend_mode mode = tegra_pmc_get_suspend_mode();
320 
321 	if (WARN_ON(mode < TEGRA_SUSPEND_NONE ||
322 		    mode >= TEGRA_MAX_SUSPEND_MODE))
323 		return -EINVAL;
324 
325 	pr_info("Entering suspend state %s\n", lp_state[mode]);
326 
327 	tegra_pm_set(mode);
328 
329 	local_fiq_disable();
330 
331 	suspend_cpu_complex();
332 	switch (mode) {
333 	case TEGRA_SUSPEND_LP1:
334 		tegra_suspend_enter_lp1();
335 		break;
336 	case TEGRA_SUSPEND_LP2:
337 		tegra_set_cpu_in_lp2();
338 		break;
339 	default:
340 		break;
341 	}
342 
343 	cpu_suspend(PHYS_OFFSET - PAGE_OFFSET, tegra_sleep_func);
344 
345 	switch (mode) {
346 	case TEGRA_SUSPEND_LP1:
347 		tegra_suspend_exit_lp1();
348 		break;
349 	case TEGRA_SUSPEND_LP2:
350 		tegra_clear_cpu_in_lp2();
351 		break;
352 	default:
353 		break;
354 	}
355 	restore_cpu_complex();
356 
357 	local_fiq_enable();
358 
359 	return 0;
360 }
361 
362 static const struct platform_suspend_ops tegra_suspend_ops = {
363 	.valid		= suspend_valid_only_mem,
364 	.enter		= tegra_suspend_enter,
365 };
366 
367 void __init tegra_init_suspend(void)
368 {
369 	enum tegra_suspend_mode mode = tegra_pmc_get_suspend_mode();
370 
371 	if (mode == TEGRA_SUSPEND_NONE)
372 		return;
373 
374 	tegra_tear_down_cpu_init();
375 
376 	if (mode >= TEGRA_SUSPEND_LP1) {
377 		if (!tegra_lp1_iram_hook() || !tegra_sleep_core_init()) {
378 			pr_err("%s: unable to allocate memory for SDRAM"
379 			       "self-refresh -- LP0/LP1 unavailable\n",
380 			       __func__);
381 			tegra_pmc_set_suspend_mode(TEGRA_SUSPEND_LP2);
382 			mode = TEGRA_SUSPEND_LP2;
383 		}
384 	}
385 
386 	/* set up sleep function for cpu_suspend */
387 	switch (mode) {
388 	case TEGRA_SUSPEND_LP1:
389 		tegra_sleep_func = tegra_sleep_core;
390 		break;
391 	case TEGRA_SUSPEND_LP2:
392 		tegra_sleep_func = tegra_sleep_cpu;
393 		break;
394 	default:
395 		break;
396 	}
397 
398 	suspend_set_ops(&tegra_suspend_ops);
399 }
400 #endif
401