1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * OMAP MPUSS low power code
4 *
5 * Copyright (C) 2011 Texas Instruments, Inc.
6 * Santosh Shilimkar <santosh.shilimkar@ti.com>
7 *
8 * OMAP4430 MPUSS mainly consists of dual Cortex-A9 with per-CPU
9 * Local timer and Watchdog, GIC, SCU, PL310 L2 cache controller,
10 * CPU0 and CPU1 LPRM modules.
11 * CPU0, CPU1 and MPUSS each have there own power domain and
12 * hence multiple low power combinations of MPUSS are possible.
13 *
14 * The CPU0 and CPU1 can't support Closed switch Retention (CSWR)
15 * because the mode is not supported by hw constraints of dormant
16 * mode. While waking up from the dormant mode, a reset signal
17 * to the Cortex-A9 processor must be asserted by the external
18 * power controller.
19 *
20 * With architectural inputs and hardware recommendations, only
21 * below modes are supported from power gain vs latency point of view.
22 *
23 * CPU0 CPU1 MPUSS
24 * ----------------------------------------------
25 * ON ON ON
26 * ON(Inactive) OFF ON(Inactive)
27 * OFF OFF CSWR
28 * OFF OFF OSWR
29 * OFF OFF OFF(Device OFF *TBD)
30 * ----------------------------------------------
31 *
32 * Note: CPU0 is the master core and it is the last CPU to go down
33 * and first to wake-up when MPUSS low power states are excercised
34 */
35
36#include <linux/cpuidle.h>
37#include <linux/kernel.h>
38#include <linux/io.h>
39#include <linux/errno.h>
40#include <linux/linkage.h>
41#include <linux/smp.h>
42
43#include <asm/cacheflush.h>
44#include <asm/tlbflush.h>
45#include <asm/smp_scu.h>
46#include <asm/suspend.h>
47#include <asm/virt.h>
48#include <asm/hardware/cache-l2x0.h>
49
50#include "soc.h"
51#include "common.h"
52#include "omap44xx.h"
53#include "omap4-sar-layout.h"
54#include "pm.h"
55#include "prcm_mpu44xx.h"
56#include "prcm_mpu54xx.h"
57#include "prminst44xx.h"
58#include "prcm44xx.h"
59#include "prm44xx.h"
60#include "prm-regbits-44xx.h"
61
62static void __iomem *sar_base;
63static u32 old_cpu1_ns_pa_addr;
64
65#if defined(CONFIG_PM) && defined(CONFIG_SMP)
66
67struct omap4_cpu_pm_info {
68 struct powerdomain *pwrdm;
69 void __iomem *scu_sar_addr;
70 void __iomem *wkup_sar_addr;
71 void __iomem *l2x0_sar_addr;
72};
73
74/**
75 * struct cpu_pm_ops - CPU pm operations
76 * @finish_suspend: CPU suspend finisher function pointer
77 * @resume: CPU resume function pointer
78 * @scu_prepare: CPU Snoop Control program function pointer
79 * @hotplug_restart: CPU restart function pointer
80 *
81 * Structure holds functions pointer for CPU low power operations like
82 * suspend, resume and scu programming.
83 */
84struct cpu_pm_ops {
85 int (*finish_suspend)(unsigned long cpu_state);
86 void (*resume)(void);
87 void (*scu_prepare)(unsigned int cpu_id, unsigned int cpu_state);
88 void (*hotplug_restart)(void);
89};
90
91static DEFINE_PER_CPU(struct omap4_cpu_pm_info, omap4_pm_info);
92static struct powerdomain *mpuss_pd;
93static u32 cpu_context_offset;
94
95static int default_finish_suspend(unsigned long cpu_state)
96{
97 omap_do_wfi();
98 return 0;
99}
100
101static void dummy_cpu_resume(void)
102{}
103
104static void dummy_scu_prepare(unsigned int cpu_id, unsigned int cpu_state)
105{}
106
107static struct cpu_pm_ops omap_pm_ops = {
108 .finish_suspend = default_finish_suspend,
109 .resume = dummy_cpu_resume,
110 .scu_prepare = dummy_scu_prepare,
111 .hotplug_restart = dummy_cpu_resume,
112};
113
114/*
115 * Program the wakeup routine address for the CPU0 and CPU1
116 * used for OFF or DORMANT wakeup.
117 */
118static inline void set_cpu_wakeup_addr(unsigned int cpu_id, u32 addr)
119{
120 struct omap4_cpu_pm_info *pm_info = &per_cpu(omap4_pm_info, cpu_id);
121
122 if (pm_info->wkup_sar_addr)
123 writel_relaxed(addr, pm_info->wkup_sar_addr);
124}
125
126/*
127 * Store the SCU power status value to scratchpad memory
128 */
129static void scu_pwrst_prepare(unsigned int cpu_id, unsigned int cpu_state)
130{
131 struct omap4_cpu_pm_info *pm_info = &per_cpu(omap4_pm_info, cpu_id);
132 u32 scu_pwr_st;
133
134 switch (cpu_state) {
135 case PWRDM_POWER_RET:
136 scu_pwr_st = SCU_PM_DORMANT;
137 break;
138 case PWRDM_POWER_OFF:
139 scu_pwr_st = SCU_PM_POWEROFF;
140 break;
141 case PWRDM_POWER_ON:
142 case PWRDM_POWER_INACTIVE:
143 default:
144 scu_pwr_st = SCU_PM_NORMAL;
145 break;
146 }
147
148 if (pm_info->scu_sar_addr)
149 writel_relaxed(scu_pwr_st, pm_info->scu_sar_addr);
150}
151
152/* Helper functions for MPUSS OSWR */
153static inline void mpuss_clear_prev_logic_pwrst(void)
154{
155 u32 reg;
156
157 reg = omap4_prminst_read_inst_reg(OMAP4430_PRM_PARTITION,
158 OMAP4430_PRM_MPU_INST, OMAP4_RM_MPU_MPU_CONTEXT_OFFSET);
159 omap4_prminst_write_inst_reg(val: reg, OMAP4430_PRM_PARTITION,
160 OMAP4430_PRM_MPU_INST, OMAP4_RM_MPU_MPU_CONTEXT_OFFSET);
161}
162
163static inline void cpu_clear_prev_logic_pwrst(unsigned int cpu_id)
164{
165 u32 reg;
166
167 if (cpu_id) {
168 reg = omap4_prcm_mpu_read_inst_reg(OMAP4430_PRCM_MPU_CPU1_INST,
169 idx: cpu_context_offset);
170 omap4_prcm_mpu_write_inst_reg(val: reg, OMAP4430_PRCM_MPU_CPU1_INST,
171 idx: cpu_context_offset);
172 } else {
173 reg = omap4_prcm_mpu_read_inst_reg(OMAP4430_PRCM_MPU_CPU0_INST,
174 idx: cpu_context_offset);
175 omap4_prcm_mpu_write_inst_reg(val: reg, OMAP4430_PRCM_MPU_CPU0_INST,
176 idx: cpu_context_offset);
177 }
178}
179
180/*
181 * Store the CPU cluster state for L2X0 low power operations.
182 */
183static void l2x0_pwrst_prepare(unsigned int cpu_id, unsigned int save_state)
184{
185 struct omap4_cpu_pm_info *pm_info = &per_cpu(omap4_pm_info, cpu_id);
186
187 if (pm_info->l2x0_sar_addr)
188 writel_relaxed(save_state, pm_info->l2x0_sar_addr);
189}
190
191/*
192 * Save the L2X0 AUXCTRL and POR value to SAR memory. Its used to
193 * in every restore MPUSS OFF path.
194 */
195#ifdef CONFIG_CACHE_L2X0
196static void __init save_l2x0_context(void)
197{
198 void __iomem *l2x0_base = omap4_get_l2cache_base();
199
200 if (l2x0_base && sar_base) {
201 writel_relaxed(l2x0_saved_regs.aux_ctrl,
202 sar_base + L2X0_AUXCTRL_OFFSET);
203 writel_relaxed(l2x0_saved_regs.prefetch_ctrl,
204 sar_base + L2X0_PREFETCH_CTRL_OFFSET);
205 }
206}
207#else
208static void __init save_l2x0_context(void)
209{}
210#endif
211
212/**
213 * omap4_enter_lowpower: OMAP4 MPUSS Low Power Entry Function
214 * The purpose of this function is to manage low power programming
215 * of OMAP4 MPUSS subsystem
216 * @cpu : CPU ID
217 * @power_state: Low power state.
218 * @rcuidle: RCU needs to be idled
219 *
220 * MPUSS states for the context save:
221 * save_state =
222 * 0 - Nothing lost and no need to save: MPUSS INACTIVE
223 * 1 - CPUx L1 and logic lost: MPUSS CSWR
224 * 2 - CPUx L1 and logic lost + GIC lost: MPUSS OSWR
225 * 3 - CPUx L1 and logic lost + GIC + L2 lost: DEVICE OFF
226 */
227__cpuidle int omap4_enter_lowpower(unsigned int cpu, unsigned int power_state,
228 bool rcuidle)
229{
230 struct omap4_cpu_pm_info *pm_info = &per_cpu(omap4_pm_info, cpu);
231 unsigned int save_state = 0, cpu_logic_state = PWRDM_POWER_RET;
232
233 if (omap_rev() == OMAP4430_REV_ES1_0)
234 return -ENXIO;
235
236 switch (power_state) {
237 case PWRDM_POWER_ON:
238 case PWRDM_POWER_INACTIVE:
239 save_state = 0;
240 break;
241 case PWRDM_POWER_OFF:
242 cpu_logic_state = PWRDM_POWER_OFF;
243 save_state = 1;
244 break;
245 case PWRDM_POWER_RET:
246 if (IS_PM44XX_ERRATUM(PM_OMAP4_CPU_OSWR_DISABLE))
247 save_state = 0;
248 break;
249 default:
250 /*
251 * CPUx CSWR is invalid hardware state. Also CPUx OSWR
252 * doesn't make much scense, since logic is lost and $L1
253 * needs to be cleaned because of coherency. This makes
254 * CPUx OSWR equivalent to CPUX OFF and hence not supported
255 */
256 WARN_ON(1);
257 return -ENXIO;
258 }
259
260 pwrdm_pre_transition(NULL);
261
262 /*
263 * Check MPUSS next state and save interrupt controller if needed.
264 * In MPUSS OSWR or device OFF, interrupt controller contest is lost.
265 */
266 mpuss_clear_prev_logic_pwrst();
267 if ((pwrdm_read_next_pwrst(pwrdm: mpuss_pd) == PWRDM_POWER_RET) &&
268 (pwrdm_read_logic_retst(pwrdm: mpuss_pd) == PWRDM_POWER_OFF))
269 save_state = 2;
270
271 cpu_clear_prev_logic_pwrst(cpu_id: cpu);
272 pwrdm_set_next_pwrst(pwrdm: pm_info->pwrdm, pwrst: power_state);
273 pwrdm_set_logic_retst(pwrdm: pm_info->pwrdm, pwrst: cpu_logic_state);
274
275 if (rcuidle)
276 ct_cpuidle_enter();
277
278 set_cpu_wakeup_addr(cpu_id: cpu, __pa_symbol(omap_pm_ops.resume));
279 omap_pm_ops.scu_prepare(cpu, power_state);
280 l2x0_pwrst_prepare(cpu_id: cpu, save_state);
281
282 /*
283 * Call low level function with targeted low power state.
284 */
285 if (save_state)
286 cpu_suspend(save_state, omap_pm_ops.finish_suspend);
287 else
288 omap_pm_ops.finish_suspend(save_state);
289
290 if (IS_PM44XX_ERRATUM(PM_OMAP4_ROM_SMP_BOOT_ERRATUM_GICD) && cpu)
291 gic_dist_enable();
292
293 if (rcuidle)
294 ct_cpuidle_exit();
295
296 /*
297 * Restore the CPUx power state to ON otherwise CPUx
298 * power domain can transitions to programmed low power
299 * state while doing WFI outside the low powe code. On
300 * secure devices, CPUx does WFI which can result in
301 * domain transition
302 */
303 pwrdm_set_next_pwrst(pwrdm: pm_info->pwrdm, PWRDM_POWER_ON);
304
305 pwrdm_post_transition(NULL);
306
307 return 0;
308}
309
310/**
311 * omap4_hotplug_cpu: OMAP4 CPU hotplug entry
312 * @cpu : CPU ID
313 * @power_state: CPU low power state.
314 */
315int omap4_hotplug_cpu(unsigned int cpu, unsigned int power_state)
316{
317 struct omap4_cpu_pm_info *pm_info = &per_cpu(omap4_pm_info, cpu);
318 unsigned int cpu_state = 0;
319
320 if (omap_rev() == OMAP4430_REV_ES1_0)
321 return -ENXIO;
322
323 /* Use the achievable power state for the domain */
324 power_state = pwrdm_get_valid_lp_state(pwrdm: pm_info->pwrdm,
325 is_logic_state: false, req_state: power_state);
326
327 if (power_state == PWRDM_POWER_OFF)
328 cpu_state = 1;
329
330 pwrdm_clear_all_prev_pwrst(pwrdm: pm_info->pwrdm);
331 pwrdm_set_next_pwrst(pwrdm: pm_info->pwrdm, pwrst: power_state);
332 set_cpu_wakeup_addr(cpu_id: cpu, __pa_symbol(omap_pm_ops.hotplug_restart));
333 omap_pm_ops.scu_prepare(cpu, power_state);
334
335 /*
336 * CPU never retuns back if targeted power state is OFF mode.
337 * CPU ONLINE follows normal CPU ONLINE ptah via
338 * omap4_secondary_startup().
339 */
340 omap_pm_ops.finish_suspend(cpu_state);
341
342 pwrdm_set_next_pwrst(pwrdm: pm_info->pwrdm, PWRDM_POWER_ON);
343 return 0;
344}
345
346
347/*
348 * Enable Mercury Fast HG retention mode by default.
349 */
350static void enable_mercury_retention_mode(void)
351{
352 u32 reg;
353
354 reg = omap4_prcm_mpu_read_inst_reg(OMAP54XX_PRCM_MPU_DEVICE_INST,
355 OMAP54XX_PRCM_MPU_PRM_PSCON_COUNT_OFFSET);
356 /* Enable HG_EN, HG_RAMPUP = fast mode */
357 reg |= BIT(24) | BIT(25);
358 omap4_prcm_mpu_write_inst_reg(val: reg, OMAP54XX_PRCM_MPU_DEVICE_INST,
359 OMAP54XX_PRCM_MPU_PRM_PSCON_COUNT_OFFSET);
360}
361
362/*
363 * Initialise OMAP4 MPUSS
364 */
365int __init omap4_mpuss_init(void)
366{
367 struct omap4_cpu_pm_info *pm_info;
368
369 if (omap_rev() == OMAP4430_REV_ES1_0) {
370 WARN(1, "Power Management not supported on OMAP4430 ES1.0\n");
371 return -ENODEV;
372 }
373
374 /* Initilaise per CPU PM information */
375 pm_info = &per_cpu(omap4_pm_info, 0x0);
376 if (sar_base) {
377 pm_info->scu_sar_addr = sar_base + SCU_OFFSET0;
378 if (cpu_is_omap44xx())
379 pm_info->wkup_sar_addr = sar_base +
380 CPU0_WAKEUP_NS_PA_ADDR_OFFSET;
381 else
382 pm_info->wkup_sar_addr = sar_base +
383 OMAP5_CPU0_WAKEUP_NS_PA_ADDR_OFFSET;
384 pm_info->l2x0_sar_addr = sar_base + L2X0_SAVE_OFFSET0;
385 }
386 pm_info->pwrdm = pwrdm_lookup(name: "cpu0_pwrdm");
387 if (!pm_info->pwrdm) {
388 pr_err("Lookup failed for CPU0 pwrdm\n");
389 return -ENODEV;
390 }
391
392 /* Clear CPU previous power domain state */
393 pwrdm_clear_all_prev_pwrst(pwrdm: pm_info->pwrdm);
394 cpu_clear_prev_logic_pwrst(cpu_id: 0);
395
396 /* Initialise CPU0 power domain state to ON */
397 pwrdm_set_next_pwrst(pwrdm: pm_info->pwrdm, PWRDM_POWER_ON);
398
399 pm_info = &per_cpu(omap4_pm_info, 0x1);
400 if (sar_base) {
401 pm_info->scu_sar_addr = sar_base + SCU_OFFSET1;
402 if (cpu_is_omap44xx())
403 pm_info->wkup_sar_addr = sar_base +
404 CPU1_WAKEUP_NS_PA_ADDR_OFFSET;
405 else
406 pm_info->wkup_sar_addr = sar_base +
407 OMAP5_CPU1_WAKEUP_NS_PA_ADDR_OFFSET;
408 pm_info->l2x0_sar_addr = sar_base + L2X0_SAVE_OFFSET1;
409 }
410
411 pm_info->pwrdm = pwrdm_lookup(name: "cpu1_pwrdm");
412 if (!pm_info->pwrdm) {
413 pr_err("Lookup failed for CPU1 pwrdm\n");
414 return -ENODEV;
415 }
416
417 /* Clear CPU previous power domain state */
418 pwrdm_clear_all_prev_pwrst(pwrdm: pm_info->pwrdm);
419 cpu_clear_prev_logic_pwrst(cpu_id: 1);
420
421 /* Initialise CPU1 power domain state to ON */
422 pwrdm_set_next_pwrst(pwrdm: pm_info->pwrdm, PWRDM_POWER_ON);
423
424 mpuss_pd = pwrdm_lookup(name: "mpu_pwrdm");
425 if (!mpuss_pd) {
426 pr_err("Failed to lookup MPUSS power domain\n");
427 return -ENODEV;
428 }
429 pwrdm_clear_all_prev_pwrst(pwrdm: mpuss_pd);
430 mpuss_clear_prev_logic_pwrst();
431
432 if (sar_base) {
433 /* Save device type on scratchpad for low level code to use */
434 writel_relaxed((omap_type() != OMAP2_DEVICE_TYPE_GP) ? 1 : 0,
435 sar_base + OMAP_TYPE_OFFSET);
436 save_l2x0_context();
437 }
438
439 if (cpu_is_omap44xx()) {
440 omap_pm_ops.finish_suspend = omap4_finish_suspend;
441 omap_pm_ops.resume = omap4_cpu_resume;
442 omap_pm_ops.scu_prepare = scu_pwrst_prepare;
443 omap_pm_ops.hotplug_restart = omap4_secondary_startup;
444 cpu_context_offset = OMAP4_RM_CPU0_CPU0_CONTEXT_OFFSET;
445 } else if (soc_is_omap54xx() || soc_is_dra7xx()) {
446 cpu_context_offset = OMAP54XX_RM_CPU0_CPU0_CONTEXT_OFFSET;
447 enable_mercury_retention_mode();
448 }
449
450 if (cpu_is_omap446x())
451 omap_pm_ops.hotplug_restart = omap4460_secondary_startup;
452
453 return 0;
454}
455
456#endif
457
458u32 omap4_get_cpu1_ns_pa_addr(void)
459{
460 return old_cpu1_ns_pa_addr;
461}
462
463/*
464 * For kexec, we must set CPU1_WAKEUP_NS_PA_ADDR to point to
465 * current kernel's secondary_startup() early before
466 * clockdomains_init(). Otherwise clockdomain_init() can
467 * wake CPU1 and cause a hang.
468 */
469void __init omap4_mpuss_early_init(void)
470{
471 unsigned long startup_pa;
472 void __iomem *ns_pa_addr;
473
474 if (!(soc_is_omap44xx() || soc_is_omap54xx()))
475 return;
476
477 sar_base = omap4_get_sar_ram_base();
478
479 /* Save old NS_PA_ADDR for validity checks later on */
480 if (soc_is_omap44xx())
481 ns_pa_addr = sar_base + CPU1_WAKEUP_NS_PA_ADDR_OFFSET;
482 else
483 ns_pa_addr = sar_base + OMAP5_CPU1_WAKEUP_NS_PA_ADDR_OFFSET;
484 old_cpu1_ns_pa_addr = readl_relaxed(ns_pa_addr);
485
486 if (soc_is_omap443x())
487 startup_pa = __pa_symbol(omap4_secondary_startup);
488 else if (soc_is_omap446x())
489 startup_pa = __pa_symbol(omap4460_secondary_startup);
490 else if ((__boot_cpu_mode & MODE_MASK) == HYP_MODE)
491 startup_pa = __pa_symbol(omap5_secondary_hyp_startup);
492 else
493 startup_pa = __pa_symbol(omap5_secondary_startup);
494
495 if (soc_is_omap44xx())
496 writel_relaxed(startup_pa, sar_base +
497 CPU1_WAKEUP_NS_PA_ADDR_OFFSET);
498 else
499 writel_relaxed(startup_pa, sar_base +
500 OMAP5_CPU1_WAKEUP_NS_PA_ADDR_OFFSET);
501}
502

source code of linux/arch/arm/mach-omap2/omap-mpuss-lowpower.c