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  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * CPU complex suspend & resume functions for Tegra SoCs
  4 *
  5 * Copyright (c) 2009-2012, NVIDIA Corporation. All rights reserved.
  6 */
  7
  8#include <linux/clk/tegra.h>
  9#include <linux/cpumask.h>
 10#include <linux/cpu_pm.h>
 11#include <linux/delay.h>
 12#include <linux/err.h>
 13#include <linux/io.h>
 14#include <linux/kernel.h>
 15#include <linux/slab.h>
 16#include <linux/spinlock.h>
 17#include <linux/suspend.h>
 18
 19#include <linux/firmware/trusted_foundations.h>
 20
 21#include <soc/tegra/flowctrl.h>
 22#include <soc/tegra/fuse.h>
 23#include <soc/tegra/pm.h>
 24#include <soc/tegra/pmc.h>
 25
 26#include <asm/cacheflush.h>
 27#include <asm/firmware.h>
 28#include <asm/idmap.h>
 29#include <asm/proc-fns.h>
 30#include <asm/smp_plat.h>
 31#include <asm/suspend.h>
 32#include <asm/tlbflush.h>
 33
 34#include "iomap.h"
 35#include "pm.h"
 36#include "reset.h"
 37#include "sleep.h"
 38
 39#ifdef CONFIG_PM_SLEEP
 40static DEFINE_SPINLOCK(tegra_lp2_lock);
 41static u32 iram_save_size;
 42static void *iram_save_addr;
 43struct tegra_lp1_iram tegra_lp1_iram;
 44void (*tegra_tear_down_cpu)(void);
 45void (*tegra_sleep_core_finish)(unsigned long v2p);
 46static int (*tegra_sleep_func)(unsigned long v2p);
 47
 48static void tegra_tear_down_cpu_init(void)
 49{
 50	switch (tegra_get_chip_id()) {
 51	case TEGRA20:
 52		if (IS_ENABLED(CONFIG_ARCH_TEGRA_2x_SOC))
 53			tegra_tear_down_cpu = tegra20_tear_down_cpu;
 54		break;
 55	case TEGRA30:
 56	case TEGRA114:
 57	case TEGRA124:
 58		if (IS_ENABLED(CONFIG_ARCH_TEGRA_3x_SOC) ||
 59		    IS_ENABLED(CONFIG_ARCH_TEGRA_114_SOC) ||
 60		    IS_ENABLED(CONFIG_ARCH_TEGRA_124_SOC))
 61			tegra_tear_down_cpu = tegra30_tear_down_cpu;
 62		break;
 63	}
 64}
 65
 66/*
 67 * restore_cpu_complex
 68 *
 69 * restores cpu clock setting, clears flow controller
 70 *
 71 * Always called on CPU 0.
 72 */
 73static void restore_cpu_complex(void)
 74{
 75	int cpu = smp_processor_id();
 76
 77	BUG_ON(cpu != 0);
 78
 79#ifdef CONFIG_SMP
 80	cpu = cpu_logical_map(cpu);
 81#endif
 82
 83	/* Restore the CPU clock settings */
 84	tegra_cpu_clock_resume();
 85
 86	flowctrl_cpu_suspend_exit(cpu);
 87}
 88
 89/*
 90 * suspend_cpu_complex
 91 *
 92 * saves pll state for use by restart_plls, prepares flow controller for
 93 * transition to suspend state
 94 *
 95 * Must always be called on cpu 0.
 96 */
 97static void suspend_cpu_complex(void)
 98{
 99	int cpu = smp_processor_id();
100
101	BUG_ON(cpu != 0);
102
103#ifdef CONFIG_SMP
104	cpu = cpu_logical_map(cpu);
105#endif
106
107	/* Save the CPU clock settings */
108	tegra_cpu_clock_suspend();
109
110	flowctrl_cpu_suspend_enter(cpu);
111}
112
113void tegra_clear_cpu_in_lp2(void)
114{
115	int phy_cpu_id = cpu_logical_map(smp_processor_id());
116	u32 *cpu_in_lp2 = tegra_cpu_lp2_mask;
117
118	spin_lock(&tegra_lp2_lock);
119
120	BUG_ON(!(*cpu_in_lp2 & BIT(phy_cpu_id)));
121	*cpu_in_lp2 &= ~BIT(phy_cpu_id);
122
123	spin_unlock(&tegra_lp2_lock);
124}
125
126bool tegra_set_cpu_in_lp2(void)
127{
128	int phy_cpu_id = cpu_logical_map(smp_processor_id());
129	bool last_cpu = false;
130	cpumask_t *cpu_lp2_mask = tegra_cpu_lp2_mask;
131	u32 *cpu_in_lp2 = tegra_cpu_lp2_mask;
132
133	spin_lock(&tegra_lp2_lock);
134
135	BUG_ON((*cpu_in_lp2 & BIT(phy_cpu_id)));
136	*cpu_in_lp2 |= BIT(phy_cpu_id);
137
138	if ((phy_cpu_id == 0) && cpumask_equal(cpu_lp2_mask, cpu_online_mask))
139		last_cpu = true;
140	else if (tegra_get_chip_id() == TEGRA20 && phy_cpu_id == 1)
141		tegra20_cpu_set_resettable_soon();
142
143	spin_unlock(&tegra_lp2_lock);
144	return last_cpu;
145}
146
147int tegra_cpu_do_idle(void)
148{
149	return cpu_do_idle();
150}
151
152static int tegra_sleep_cpu(unsigned long v2p)
153{
154	/*
155	 * L2 cache disabling using kernel API only allowed when all
156	 * secondary CPU's are offline. Cache have to be disabled with
157	 * MMU-on if cache maintenance is done via Trusted Foundations
158	 * firmware. Note that CPUIDLE won't ever enter powergate on Tegra30
159	 * if any of secondary CPU's is online and this is the LP2-idle
160	 * code-path only for Tegra20/30.
161	 */
162	if (trusted_foundations_registered())
163		outer_disable();
164
165	/*
166	 * Note that besides of setting up CPU reset vector this firmware
167	 * call may also do the following, depending on the FW version:
168	 *  1) Disable L2. But this doesn't matter since we already
169	 *     disabled the L2.
170	 *  2) Disable D-cache. This need to be taken into account in
171	 *     particular by the tegra_disable_clean_inv_dcache() which
172	 *     shall avoid the re-disable.
173	 */
174	call_firmware_op(prepare_idle, TF_PM_MODE_LP2);
175
176	setup_mm_for_reboot();
177	tegra_sleep_cpu_finish(v2p);
178
179	/* should never here */
180	BUG();
181
182	return 0;
183}
184
185static void tegra_pm_set(enum tegra_suspend_mode mode)
186{
187	u32 value;
188
189	switch (tegra_get_chip_id()) {
190	case TEGRA20:
191	case TEGRA30:
192		break;
193	default:
194		/* Turn off CRAIL */
195		value = flowctrl_read_cpu_csr(0);
196		value &= ~FLOW_CTRL_CSR_ENABLE_EXT_MASK;
197		value |= FLOW_CTRL_CSR_ENABLE_EXT_CRAIL;
198		flowctrl_write_cpu_csr(0, value);
199		break;
200	}
201
202	tegra_pmc_enter_suspend_mode(mode);
203}
204
205void tegra_idle_lp2_last(void)
206{
207	tegra_pm_set(TEGRA_SUSPEND_LP2);
208
209	cpu_cluster_pm_enter();
210	suspend_cpu_complex();
211
212	cpu_suspend(PHYS_OFFSET - PAGE_OFFSET, &tegra_sleep_cpu);
213
214	/*
215	 * Resume L2 cache if it wasn't re-enabled early during resume,
216	 * which is the case for Tegra30 that has to re-enable the cache
217	 * via firmware call. In other cases cache is already enabled and
218	 * hence re-enabling is a no-op. This is always a no-op on Tegra114+.
219	 */
220	outer_resume();
221
222	restore_cpu_complex();
223	cpu_cluster_pm_exit();
224}
225
226enum tegra_suspend_mode tegra_pm_validate_suspend_mode(
227				enum tegra_suspend_mode mode)
228{
229	/*
230	 * The Tegra devices support suspending to LP1 or lower currently.
231	 */
232	if (mode > TEGRA_SUSPEND_LP1)
233		return TEGRA_SUSPEND_LP1;
234
235	return mode;
236}
237
238static int tegra_sleep_core(unsigned long v2p)
239{
240	/*
241	 * Cache have to be disabled with MMU-on if cache maintenance is done
242	 * via Trusted Foundations firmware. This is a no-op on Tegra114+.
243	 */
244	if (trusted_foundations_registered())
245		outer_disable();
246
247	call_firmware_op(prepare_idle, TF_PM_MODE_LP1);
248
249	setup_mm_for_reboot();
250	tegra_sleep_core_finish(v2p);
251
252	/* should never here */
253	BUG();
254
255	return 0;
256}
257
258/*
259 * tegra_lp1_iram_hook
260 *
261 * Hooking the address of LP1 reset vector and SDRAM self-refresh code in
262 * SDRAM. These codes not be copied to IRAM in this fuction. We need to
263 * copy these code to IRAM before LP0/LP1 suspend and restore the content
264 * of IRAM after resume.
265 */
266static bool tegra_lp1_iram_hook(void)
267{
268	switch (tegra_get_chip_id()) {
269	case TEGRA20:
270		if (IS_ENABLED(CONFIG_ARCH_TEGRA_2x_SOC))
271			tegra20_lp1_iram_hook();
272		break;
273	case TEGRA30:
274	case TEGRA114:
275	case TEGRA124:
276		if (IS_ENABLED(CONFIG_ARCH_TEGRA_3x_SOC) ||
277		    IS_ENABLED(CONFIG_ARCH_TEGRA_114_SOC) ||
278		    IS_ENABLED(CONFIG_ARCH_TEGRA_124_SOC))
279			tegra30_lp1_iram_hook();
280		break;
281	default:
282		break;
283	}
284
285	if (!tegra_lp1_iram.start_addr || !tegra_lp1_iram.end_addr)
286		return false;
287
288	iram_save_size = tegra_lp1_iram.end_addr - tegra_lp1_iram.start_addr;
289	iram_save_addr = kmalloc(iram_save_size, GFP_KERNEL);
290	if (!iram_save_addr)
291		return false;
292
293	return true;
294}
295
296static bool tegra_sleep_core_init(void)
297{
298	switch (tegra_get_chip_id()) {
299	case TEGRA20:
300		if (IS_ENABLED(CONFIG_ARCH_TEGRA_2x_SOC))
301			tegra20_sleep_core_init();
302		break;
303	case TEGRA30:
304	case TEGRA114:
305	case TEGRA124:
306		if (IS_ENABLED(CONFIG_ARCH_TEGRA_3x_SOC) ||
307		    IS_ENABLED(CONFIG_ARCH_TEGRA_114_SOC) ||
308		    IS_ENABLED(CONFIG_ARCH_TEGRA_124_SOC))
309			tegra30_sleep_core_init();
310		break;
311	default:
312		break;
313	}
314
315	if (!tegra_sleep_core_finish)
316		return false;
317
318	return true;
319}
320
321static void tegra_suspend_enter_lp1(void)
322{
323	/* copy the reset vector & SDRAM shutdown code into IRAM */
324	memcpy(iram_save_addr, IO_ADDRESS(TEGRA_IRAM_LPx_RESUME_AREA),
325		iram_save_size);
326	memcpy(IO_ADDRESS(TEGRA_IRAM_LPx_RESUME_AREA),
327		tegra_lp1_iram.start_addr, iram_save_size);
328
329	*((u32 *)tegra_cpu_lp1_mask) = 1;
330}
331
332static void tegra_suspend_exit_lp1(void)
333{
334	/* restore IRAM */
335	memcpy(IO_ADDRESS(TEGRA_IRAM_LPx_RESUME_AREA), iram_save_addr,
336		iram_save_size);
337
338	*(u32 *)tegra_cpu_lp1_mask = 0;
339}
340
341static const char *lp_state[TEGRA_MAX_SUSPEND_MODE] = {
342	[TEGRA_SUSPEND_NONE] = "none",
343	[TEGRA_SUSPEND_LP2] = "LP2",
344	[TEGRA_SUSPEND_LP1] = "LP1",
345	[TEGRA_SUSPEND_LP0] = "LP0",
346};
347
348static int tegra_suspend_enter(suspend_state_t state)
349{
350	enum tegra_suspend_mode mode = tegra_pmc_get_suspend_mode();
351
352	if (WARN_ON(mode < TEGRA_SUSPEND_NONE ||
353		    mode >= TEGRA_MAX_SUSPEND_MODE))
354		return -EINVAL;
355
356	pr_info("Entering suspend state %s\n", lp_state[mode]);
357
358	tegra_pm_set(mode);
359
360	local_fiq_disable();
361
362	suspend_cpu_complex();
363	switch (mode) {
364	case TEGRA_SUSPEND_LP1:
365		tegra_suspend_enter_lp1();
366		break;
367	case TEGRA_SUSPEND_LP2:
368		tegra_set_cpu_in_lp2();
369		break;
370	default:
371		break;
372	}
373
374	cpu_suspend(PHYS_OFFSET - PAGE_OFFSET, tegra_sleep_func);
375
376	/*
377	 * Resume L2 cache if it wasn't re-enabled early during resume,
378	 * which is the case for Tegra30 that has to re-enable the cache
379	 * via firmware call. In other cases cache is already enabled and
380	 * hence re-enabling is a no-op.
381	 */
382	outer_resume();
383
384	switch (mode) {
385	case TEGRA_SUSPEND_LP1:
386		tegra_suspend_exit_lp1();
387		break;
388	case TEGRA_SUSPEND_LP2:
389		tegra_clear_cpu_in_lp2();
390		break;
391	default:
392		break;
393	}
394	restore_cpu_complex();
395
396	local_fiq_enable();
397
398	return 0;
399}
400
401static const struct platform_suspend_ops tegra_suspend_ops = {
402	.valid		= suspend_valid_only_mem,
403	.enter		= tegra_suspend_enter,
404};
405
406void __init tegra_init_suspend(void)
407{
408	enum tegra_suspend_mode mode = tegra_pmc_get_suspend_mode();
409
410	if (mode == TEGRA_SUSPEND_NONE)
411		return;
412
413	tegra_tear_down_cpu_init();
414
415	if (mode >= TEGRA_SUSPEND_LP1) {
416		if (!tegra_lp1_iram_hook() || !tegra_sleep_core_init()) {
417			pr_err("%s: unable to allocate memory for SDRAM"
418			       "self-refresh -- LP0/LP1 unavailable\n",
419			       __func__);
420			tegra_pmc_set_suspend_mode(TEGRA_SUSPEND_LP2);
421			mode = TEGRA_SUSPEND_LP2;
422		}
423	}
424
425	/* set up sleep function for cpu_suspend */
426	switch (mode) {
427	case TEGRA_SUSPEND_LP1:
428		tegra_sleep_func = tegra_sleep_core;
429		break;
430	case TEGRA_SUSPEND_LP2:
431		tegra_sleep_func = tegra_sleep_cpu;
432		break;
433	default:
434		break;
435	}
436
437	suspend_set_ops(&tegra_suspend_ops);
438}
439#endif