1 /*
2 * OMAP MPUSS low power code
3 *
4 * Copyright (C) 2011 Texas Instruments, Inc.
5 * Santosh Shilimkar <santosh.shilimkar@ti.com>
6 *
7 * OMAP4430 MPUSS mainly consists of dual Cortex-A9 with per-CPU
8 * Local timer and Watchdog, GIC, SCU, PL310 L2 cache controller,
9 * CPU0 and CPU1 LPRM modules.
10 * CPU0, CPU1 and MPUSS each have there own power domain and
11 * hence multiple low power combinations of MPUSS are possible.
12 *
13 * The CPU0 and CPU1 can't support Closed switch Retention (CSWR)
14 * because the mode is not supported by hw constraints of dormant
15 * mode. While waking up from the dormant mode, a reset signal
16 * to the Cortex-A9 processor must be asserted by the external
17 * power controller.
18 *
19 * With architectural inputs and hardware recommendations, only
20 * below modes are supported from power gain vs latency point of view.
21 *
22 * CPU0 CPU1 MPUSS
23 * ----------------------------------------------
24 * ON ON ON
25 * ON(Inactive) OFF ON(Inactive)
26 * OFF OFF CSWR
27 * OFF OFF OSWR
28 * OFF OFF OFF(Device OFF *TBD)
29 * ----------------------------------------------
30 *
31 * Note: CPU0 is the master core and it is the last CPU to go down
32 * and first to wake-up when MPUSS low power states are excercised
33 *
34 *
35 * This program is free software; you can redistribute it and/or modify
36 * it under the terms of the GNU General Public License version 2 as
37 * published by the Free Software Foundation.
38 */
39
40 #include <linux/kernel.h>
41 #include <linux/io.h>
42 #include <linux/errno.h>
43 #include <linux/linkage.h>
44 #include <linux/smp.h>
45
46 #include <asm/cacheflush.h>
47 #include <asm/tlbflush.h>
48 #include <asm/smp_scu.h>
49 #include <asm/pgalloc.h>
50 #include <asm/suspend.h>
51 #include <asm/hardware/cache-l2x0.h>
52
53 #include "soc.h"
54 #include "common.h"
55 #include "omap44xx.h"
56 #include "omap4-sar-layout.h"
57 #include "pm.h"
58 #include "prcm_mpu44xx.h"
59 #include "prcm_mpu54xx.h"
60 #include "prminst44xx.h"
61 #include "prcm44xx.h"
62 #include "prm44xx.h"
63 #include "prm-regbits-44xx.h"
64
65 #ifdef CONFIG_SMP
66
67 struct 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 */
84 struct 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
91 static DEFINE_PER_CPU(struct omap4_cpu_pm_info, omap4_pm_info);
92 static struct powerdomain *mpuss_pd;
93 static void __iomem *sar_base;
94 static u32 cpu_context_offset;
95
default_finish_suspend(unsigned long cpu_state)96 static int default_finish_suspend(unsigned long cpu_state)
97 {
98 omap_do_wfi();
99 return 0;
100 }
101
dummy_cpu_resume(void)102 static void dummy_cpu_resume(void)
103 {}
104
dummy_scu_prepare(unsigned int cpu_id,unsigned int cpu_state)105 static void dummy_scu_prepare(unsigned int cpu_id, unsigned int cpu_state)
106 {}
107
108 static struct cpu_pm_ops omap_pm_ops = {
109 .finish_suspend = default_finish_suspend,
110 .resume = dummy_cpu_resume,
111 .scu_prepare = dummy_scu_prepare,
112 .hotplug_restart = dummy_cpu_resume,
113 };
114
115 /*
116 * Program the wakeup routine address for the CPU0 and CPU1
117 * used for OFF or DORMANT wakeup.
118 */
set_cpu_wakeup_addr(unsigned int cpu_id,u32 addr)119 static inline void set_cpu_wakeup_addr(unsigned int cpu_id, u32 addr)
120 {
121 struct omap4_cpu_pm_info *pm_info = &per_cpu(omap4_pm_info, cpu_id);
122
123 if (pm_info->wkup_sar_addr)
124 writel_relaxed(addr, pm_info->wkup_sar_addr);
125 }
126
127 /*
128 * Store the SCU power status value to scratchpad memory
129 */
scu_pwrst_prepare(unsigned int cpu_id,unsigned int cpu_state)130 static void scu_pwrst_prepare(unsigned int cpu_id, unsigned int cpu_state)
131 {
132 struct omap4_cpu_pm_info *pm_info = &per_cpu(omap4_pm_info, cpu_id);
133 u32 scu_pwr_st;
134
135 switch (cpu_state) {
136 case PWRDM_POWER_RET:
137 scu_pwr_st = SCU_PM_DORMANT;
138 break;
139 case PWRDM_POWER_OFF:
140 scu_pwr_st = SCU_PM_POWEROFF;
141 break;
142 case PWRDM_POWER_ON:
143 case PWRDM_POWER_INACTIVE:
144 default:
145 scu_pwr_st = SCU_PM_NORMAL;
146 break;
147 }
148
149 if (pm_info->scu_sar_addr)
150 writel_relaxed(scu_pwr_st, pm_info->scu_sar_addr);
151 }
152
153 /* Helper functions for MPUSS OSWR */
mpuss_clear_prev_logic_pwrst(void)154 static inline void mpuss_clear_prev_logic_pwrst(void)
155 {
156 u32 reg;
157
158 reg = omap4_prminst_read_inst_reg(OMAP4430_PRM_PARTITION,
159 OMAP4430_PRM_MPU_INST, OMAP4_RM_MPU_MPU_CONTEXT_OFFSET);
160 omap4_prminst_write_inst_reg(reg, OMAP4430_PRM_PARTITION,
161 OMAP4430_PRM_MPU_INST, OMAP4_RM_MPU_MPU_CONTEXT_OFFSET);
162 }
163
cpu_clear_prev_logic_pwrst(unsigned int cpu_id)164 static inline void cpu_clear_prev_logic_pwrst(unsigned int cpu_id)
165 {
166 u32 reg;
167
168 if (cpu_id) {
169 reg = omap4_prcm_mpu_read_inst_reg(OMAP4430_PRCM_MPU_CPU1_INST,
170 cpu_context_offset);
171 omap4_prcm_mpu_write_inst_reg(reg, OMAP4430_PRCM_MPU_CPU1_INST,
172 cpu_context_offset);
173 } else {
174 reg = omap4_prcm_mpu_read_inst_reg(OMAP4430_PRCM_MPU_CPU0_INST,
175 cpu_context_offset);
176 omap4_prcm_mpu_write_inst_reg(reg, OMAP4430_PRCM_MPU_CPU0_INST,
177 cpu_context_offset);
178 }
179 }
180
181 /*
182 * Store the CPU cluster state for L2X0 low power operations.
183 */
l2x0_pwrst_prepare(unsigned int cpu_id,unsigned int save_state)184 static void l2x0_pwrst_prepare(unsigned int cpu_id, unsigned int save_state)
185 {
186 struct omap4_cpu_pm_info *pm_info = &per_cpu(omap4_pm_info, cpu_id);
187
188 if (pm_info->l2x0_sar_addr)
189 writel_relaxed(save_state, pm_info->l2x0_sar_addr);
190 }
191
192 /*
193 * Save the L2X0 AUXCTRL and POR value to SAR memory. Its used to
194 * in every restore MPUSS OFF path.
195 */
196 #ifdef CONFIG_CACHE_L2X0
save_l2x0_context(void)197 static void __init save_l2x0_context(void)
198 {
199 void __iomem *l2x0_base = omap4_get_l2cache_base();
200
201 if (l2x0_base && sar_base) {
202 writel_relaxed(l2x0_saved_regs.aux_ctrl,
203 sar_base + L2X0_AUXCTRL_OFFSET);
204 writel_relaxed(l2x0_saved_regs.prefetch_ctrl,
205 sar_base + L2X0_PREFETCH_CTRL_OFFSET);
206 }
207 }
208 #else
save_l2x0_context(void)209 static void __init save_l2x0_context(void)
210 {}
211 #endif
212
213 /**
214 * omap4_enter_lowpower: OMAP4 MPUSS Low Power Entry Function
215 * The purpose of this function is to manage low power programming
216 * of OMAP4 MPUSS subsystem
217 * @cpu : CPU ID
218 * @power_state: Low power state.
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 */
omap4_enter_lowpower(unsigned int cpu,unsigned int power_state)227 int omap4_enter_lowpower(unsigned int cpu, unsigned int power_state)
228 {
229 struct omap4_cpu_pm_info *pm_info = &per_cpu(omap4_pm_info, cpu);
230 unsigned int save_state = 0, cpu_logic_state = PWRDM_POWER_RET;
231 unsigned int wakeup_cpu;
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(mpuss_pd) == PWRDM_POWER_RET) &&
268 (pwrdm_read_logic_retst(mpuss_pd) == PWRDM_POWER_OFF))
269 save_state = 2;
270
271 cpu_clear_prev_logic_pwrst(cpu);
272 pwrdm_set_next_pwrst(pm_info->pwrdm, power_state);
273 pwrdm_set_logic_retst(pm_info->pwrdm, cpu_logic_state);
274 set_cpu_wakeup_addr(cpu, virt_to_phys(omap_pm_ops.resume));
275 omap_pm_ops.scu_prepare(cpu, power_state);
276 l2x0_pwrst_prepare(cpu, save_state);
277
278 /*
279 * Call low level function with targeted low power state.
280 */
281 if (save_state)
282 cpu_suspend(save_state, omap_pm_ops.finish_suspend);
283 else
284 omap_pm_ops.finish_suspend(save_state);
285
286 if (IS_PM44XX_ERRATUM(PM_OMAP4_ROM_SMP_BOOT_ERRATUM_GICD) && cpu)
287 gic_dist_enable();
288
289 /*
290 * Restore the CPUx power state to ON otherwise CPUx
291 * power domain can transitions to programmed low power
292 * state while doing WFI outside the low powe code. On
293 * secure devices, CPUx does WFI which can result in
294 * domain transition
295 */
296 wakeup_cpu = smp_processor_id();
297 pwrdm_set_next_pwrst(pm_info->pwrdm, PWRDM_POWER_ON);
298
299 pwrdm_post_transition(NULL);
300
301 return 0;
302 }
303
304 /**
305 * omap4_hotplug_cpu: OMAP4 CPU hotplug entry
306 * @cpu : CPU ID
307 * @power_state: CPU low power state.
308 */
omap4_hotplug_cpu(unsigned int cpu,unsigned int power_state)309 int omap4_hotplug_cpu(unsigned int cpu, unsigned int power_state)
310 {
311 struct omap4_cpu_pm_info *pm_info = &per_cpu(omap4_pm_info, cpu);
312 unsigned int cpu_state = 0;
313
314 if (omap_rev() == OMAP4430_REV_ES1_0)
315 return -ENXIO;
316
317 /* Use the achievable power state for the domain */
318 power_state = pwrdm_get_valid_lp_state(pm_info->pwrdm,
319 false, power_state);
320
321 if (power_state == PWRDM_POWER_OFF)
322 cpu_state = 1;
323
324 pwrdm_clear_all_prev_pwrst(pm_info->pwrdm);
325 pwrdm_set_next_pwrst(pm_info->pwrdm, power_state);
326 set_cpu_wakeup_addr(cpu, virt_to_phys(omap_pm_ops.hotplug_restart));
327 omap_pm_ops.scu_prepare(cpu, power_state);
328
329 /*
330 * CPU never retuns back if targeted power state is OFF mode.
331 * CPU ONLINE follows normal CPU ONLINE ptah via
332 * omap4_secondary_startup().
333 */
334 omap_pm_ops.finish_suspend(cpu_state);
335
336 pwrdm_set_next_pwrst(pm_info->pwrdm, PWRDM_POWER_ON);
337 return 0;
338 }
339
340
341 /*
342 * Enable Mercury Fast HG retention mode by default.
343 */
enable_mercury_retention_mode(void)344 static void enable_mercury_retention_mode(void)
345 {
346 u32 reg;
347
348 reg = omap4_prcm_mpu_read_inst_reg(OMAP54XX_PRCM_MPU_DEVICE_INST,
349 OMAP54XX_PRCM_MPU_PRM_PSCON_COUNT_OFFSET);
350 /* Enable HG_EN, HG_RAMPUP = fast mode */
351 reg |= BIT(24) | BIT(25);
352 omap4_prcm_mpu_write_inst_reg(reg, OMAP54XX_PRCM_MPU_DEVICE_INST,
353 OMAP54XX_PRCM_MPU_PRM_PSCON_COUNT_OFFSET);
354 }
355
356 /*
357 * Initialise OMAP4 MPUSS
358 */
omap4_mpuss_init(void)359 int __init omap4_mpuss_init(void)
360 {
361 struct omap4_cpu_pm_info *pm_info;
362
363 if (omap_rev() == OMAP4430_REV_ES1_0) {
364 WARN(1, "Power Management not supported on OMAP4430 ES1.0\n");
365 return -ENODEV;
366 }
367
368 if (cpu_is_omap44xx())
369 sar_base = omap4_get_sar_ram_base();
370
371 /* Initilaise per CPU PM information */
372 pm_info = &per_cpu(omap4_pm_info, 0x0);
373 if (sar_base) {
374 pm_info->scu_sar_addr = sar_base + SCU_OFFSET0;
375 pm_info->wkup_sar_addr = sar_base +
376 CPU0_WAKEUP_NS_PA_ADDR_OFFSET;
377 pm_info->l2x0_sar_addr = sar_base + L2X0_SAVE_OFFSET0;
378 }
379 pm_info->pwrdm = pwrdm_lookup("cpu0_pwrdm");
380 if (!pm_info->pwrdm) {
381 pr_err("Lookup failed for CPU0 pwrdm\n");
382 return -ENODEV;
383 }
384
385 /* Clear CPU previous power domain state */
386 pwrdm_clear_all_prev_pwrst(pm_info->pwrdm);
387 cpu_clear_prev_logic_pwrst(0);
388
389 /* Initialise CPU0 power domain state to ON */
390 pwrdm_set_next_pwrst(pm_info->pwrdm, PWRDM_POWER_ON);
391
392 pm_info = &per_cpu(omap4_pm_info, 0x1);
393 if (sar_base) {
394 pm_info->scu_sar_addr = sar_base + SCU_OFFSET1;
395 pm_info->wkup_sar_addr = sar_base +
396 CPU1_WAKEUP_NS_PA_ADDR_OFFSET;
397 pm_info->l2x0_sar_addr = sar_base + L2X0_SAVE_OFFSET1;
398 }
399
400 pm_info->pwrdm = pwrdm_lookup("cpu1_pwrdm");
401 if (!pm_info->pwrdm) {
402 pr_err("Lookup failed for CPU1 pwrdm\n");
403 return -ENODEV;
404 }
405
406 /* Clear CPU previous power domain state */
407 pwrdm_clear_all_prev_pwrst(pm_info->pwrdm);
408 cpu_clear_prev_logic_pwrst(1);
409
410 /* Initialise CPU1 power domain state to ON */
411 pwrdm_set_next_pwrst(pm_info->pwrdm, PWRDM_POWER_ON);
412
413 mpuss_pd = pwrdm_lookup("mpu_pwrdm");
414 if (!mpuss_pd) {
415 pr_err("Failed to lookup MPUSS power domain\n");
416 return -ENODEV;
417 }
418 pwrdm_clear_all_prev_pwrst(mpuss_pd);
419 mpuss_clear_prev_logic_pwrst();
420
421 if (sar_base) {
422 /* Save device type on scratchpad for low level code to use */
423 writel_relaxed((omap_type() != OMAP2_DEVICE_TYPE_GP) ? 1 : 0,
424 sar_base + OMAP_TYPE_OFFSET);
425 save_l2x0_context();
426 }
427
428 if (cpu_is_omap44xx()) {
429 omap_pm_ops.finish_suspend = omap4_finish_suspend;
430 omap_pm_ops.resume = omap4_cpu_resume;
431 omap_pm_ops.scu_prepare = scu_pwrst_prepare;
432 omap_pm_ops.hotplug_restart = omap4_secondary_startup;
433 cpu_context_offset = OMAP4_RM_CPU0_CPU0_CONTEXT_OFFSET;
434 } else if (soc_is_omap54xx() || soc_is_dra7xx()) {
435 cpu_context_offset = OMAP54XX_RM_CPU0_CPU0_CONTEXT_OFFSET;
436 enable_mercury_retention_mode();
437 }
438
439 if (cpu_is_omap446x())
440 omap_pm_ops.hotplug_restart = omap4460_secondary_startup;
441
442 return 0;
443 }
444
445 #endif
446