aboutsummaryrefslogtreecommitdiff
path: root/arch/arm/mach-omap2/omap-mpuss-lowpower.c
blob: 637a1bdf2ac45d63a63c7d8419b5b2179d2a2022 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
/*
 * OMAP MPUSS low power code
 *
 * Copyright (C) 2011 Texas Instruments, Inc.
 *	Santosh Shilimkar <santosh.shilimkar@ti.com>
 *
 * OMAP4430 MPUSS mainly consists of dual Cortex-A9 with per-CPU
 * Local timer and Watchdog, GIC, SCU, PL310 L2 cache controller,
 * CPU0 and CPU1 LPRM modules.
 * CPU0, CPU1 and MPUSS each have there own power domain and
 * hence multiple low power combinations of MPUSS are possible.
 *
 * The CPU0 and CPU1 can't support Closed switch Retention (CSWR)
 * because the mode is not supported by hw constraints of dormant
 * mode. While waking up from the dormant mode, a reset  signal
 * to the Cortex-A9 processor must be asserted by the external
 * power controller.
 *
 * With architectural inputs and hardware recommendations, only
 * below modes are supported from power gain vs latency point of view.
 *
 *	CPU0		CPU1		MPUSS
 *	----------------------------------------------
 *	ON		ON		ON
 *	ON(Inactive)	OFF		ON(Inactive)
 *	OFF		OFF		CSWR
 *	OFF		OFF		OSWR
 *	OFF		OFF		OFF(Device OFF *TBD)
 *	----------------------------------------------
 *
 * Note: CPU0 is the master core and it is the last CPU to go down
 * and first to wake-up when MPUSS low power states are excercised
 *
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/kernel.h>
#include <linux/io.h>
#include <linux/errno.h>
#include <linux/linkage.h>
#include <linux/smp.h>

#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
#include <asm/smp_scu.h>
#include <asm/pgalloc.h>
#include <asm/suspend.h>
#include <asm/hardware/cache-l2x0.h>

#include <plat/omap44xx.h>

#include "common.h"
#include "omap4-sar-layout.h"
#include "pm.h"
#include "prcm_mpu44xx.h"
#include "prminst44xx.h"
#include "prcm44xx.h"
#include "prm44xx.h"
#include "prm-regbits-44xx.h"

#ifdef CONFIG_SMP

struct omap4_cpu_pm_info {
	struct powerdomain *pwrdm;
	void __iomem *scu_sar_addr;
	void __iomem *wkup_sar_addr;
	void __iomem *l2x0_sar_addr;
};

static DEFINE_PER_CPU(struct omap4_cpu_pm_info, omap4_pm_info);
static struct powerdomain *mpuss_pd;
static void __iomem *sar_base;

/*
 * Program the wakeup routine address for the CPU0 and CPU1
 * used for OFF or DORMANT wakeup.
 */
static inline void set_cpu_wakeup_addr(unsigned int cpu_id, u32 addr)
{
	struct omap4_cpu_pm_info *pm_info = &per_cpu(omap4_pm_info, cpu_id);

	__raw_writel(addr, pm_info->wkup_sar_addr);
}

/*
 * Set the CPUx powerdomain's previous power state
 */
static inline void set_cpu_next_pwrst(unsigned int cpu_id,
				unsigned int power_state)
{
	struct omap4_cpu_pm_info *pm_info = &per_cpu(omap4_pm_info, cpu_id);

	pwrdm_set_next_pwrst(pm_info->pwrdm, power_state);
}

/*
 * Read CPU's previous power state
 */
static inline unsigned int read_cpu_prev_pwrst(unsigned int cpu_id)
{
	struct omap4_cpu_pm_info *pm_info = &per_cpu(omap4_pm_info, cpu_id);

	return pwrdm_read_prev_pwrst(pm_info->pwrdm);
}

/*
 * Clear the CPUx powerdomain's previous power state
 */
static inline void clear_cpu_prev_pwrst(unsigned int cpu_id)
{
	struct omap4_cpu_pm_info *pm_info = &per_cpu(omap4_pm_info, cpu_id);

	pwrdm_clear_all_prev_pwrst(pm_info->pwrdm);
}

/*
 * Store the SCU power status value to scratchpad memory
 */
static void scu_pwrst_prepare(unsigned int cpu_id, unsigned int cpu_state)
{
	struct omap4_cpu_pm_info *pm_info = &per_cpu(omap4_pm_info, cpu_id);
	u32 scu_pwr_st;

	switch (cpu_state) {
	case PWRDM_POWER_RET:
		scu_pwr_st = SCU_PM_DORMANT;
		break;
	case PWRDM_POWER_OFF:
		scu_pwr_st = SCU_PM_POWEROFF;
		break;
	case PWRDM_POWER_ON:
	case PWRDM_POWER_INACTIVE:
	default:
		scu_pwr_st = SCU_PM_NORMAL;
		break;
	}

	__raw_writel(scu_pwr_st, pm_info->scu_sar_addr);
}

/* Helper functions for MPUSS OSWR */
static inline void mpuss_clear_prev_logic_pwrst(void)
{
	u32 reg;

	reg = omap4_prminst_read_inst_reg(OMAP4430_PRM_PARTITION,
		OMAP4430_PRM_MPU_INST, OMAP4_RM_MPU_MPU_CONTEXT_OFFSET);
	omap4_prminst_write_inst_reg(reg, OMAP4430_PRM_PARTITION,
		OMAP4430_PRM_MPU_INST, OMAP4_RM_MPU_MPU_CONTEXT_OFFSET);
}

static inline void cpu_clear_prev_logic_pwrst(unsigned int cpu_id)
{
	u32 reg;

	if (cpu_id) {
		reg = omap4_prcm_mpu_read_inst_reg(OMAP4430_PRCM_MPU_CPU1_INST,
					OMAP4_RM_CPU1_CPU1_CONTEXT_OFFSET);
		omap4_prcm_mpu_write_inst_reg(reg, OMAP4430_PRCM_MPU_CPU1_INST,
					OMAP4_RM_CPU1_CPU1_CONTEXT_OFFSET);
	} else {
		reg = omap4_prcm_mpu_read_inst_reg(OMAP4430_PRCM_MPU_CPU0_INST,
					OMAP4_RM_CPU0_CPU0_CONTEXT_OFFSET);
		omap4_prcm_mpu_write_inst_reg(reg, OMAP4430_PRCM_MPU_CPU0_INST,
					OMAP4_RM_CPU0_CPU0_CONTEXT_OFFSET);
	}
}

/**
 * omap4_mpuss_read_prev_context_state:
 * Function returns the MPUSS previous context state
 */
u32 omap4_mpuss_read_prev_context_state(void)
{
	u32 reg;

	reg = omap4_prminst_read_inst_reg(OMAP4430_PRM_PARTITION,
		OMAP4430_PRM_MPU_INST, OMAP4_RM_MPU_MPU_CONTEXT_OFFSET);
	reg &= OMAP4430_LOSTCONTEXT_DFF_MASK;
	return reg;
}

/*
 * Store the CPU cluster state for L2X0 low power operations.
 */
static void l2x0_pwrst_prepare(unsigned int cpu_id, unsigned int save_state)
{
	struct omap4_cpu_pm_info *pm_info = &per_cpu(omap4_pm_info, cpu_id);

	__raw_writel(save_state, pm_info->l2x0_sar_addr);
}

/*
 * Save the L2X0 AUXCTRL and POR value to SAR memory. Its used to
 * in every restore MPUSS OFF path.
 */
#ifdef CONFIG_CACHE_L2X0
static void save_l2x0_context(void)
{
	u32 val;
	void __iomem *l2x0_base = omap4_get_l2cache_base();

	val = __raw_readl(l2x0_base + L2X0_AUX_CTRL);
	__raw_writel(val, sar_base + L2X0_AUXCTRL_OFFSET);
	val = __raw_readl(l2x0_base + L2X0_PREFETCH_CTRL);
	__raw_writel(val, sar_base + L2X0_PREFETCH_CTRL_OFFSET);
}
#else
static void save_l2x0_context(void)
{}
#endif

/**
 * omap4_enter_lowpower: OMAP4 MPUSS Low Power Entry Function
 * The purpose of this function is to manage low power programming
 * of OMAP4 MPUSS subsystem
 * @cpu : CPU ID
 * @power_state: Low power state.
 *
 * MPUSS states for the context save:
 * save_state =
 *	0 - Nothing lost and no need to save: MPUSS INACTIVE
 *	1 - CPUx L1 and logic lost: MPUSS CSWR
 *	2 - CPUx L1 and logic lost + GIC lost: MPUSS OSWR
 *	3 - CPUx L1 and logic lost + GIC + L2 lost: DEVICE OFF
 */
int omap4_enter_lowpower(unsigned int cpu, unsigned int power_state)
{
	unsigned int save_state = 0;
	unsigned int wakeup_cpu;

	if (omap_rev() == OMAP4430_REV_ES1_0)
		return -ENXIO;

	switch (power_state) {
	case PWRDM_POWER_ON:
	case PWRDM_POWER_INACTIVE:
		save_state = 0;
		break;
	case PWRDM_POWER_OFF:
		save_state = 1;
		break;
	case PWRDM_POWER_RET:
	default:
		/*
		 * CPUx CSWR is invalid hardware state. Also CPUx OSWR
		 * doesn't make much scense, since logic is lost and $L1
		 * needs to be cleaned because of coherency. This makes
		 * CPUx OSWR equivalent to CPUX OFF and hence not supported
		 */
		WARN_ON(1);
		return -ENXIO;
	}

	pwrdm_pre_transition(NULL);

	/*
	 * Check MPUSS next state and save interrupt controller if needed.
	 * In MPUSS OSWR or device OFF, interrupt controller  contest is lost.
	 */
	mpuss_clear_prev_logic_pwrst();
	if ((pwrdm_read_next_pwrst(mpuss_pd) == PWRDM_POWER_RET) &&
		(pwrdm_read_logic_retst(mpuss_pd) == PWRDM_POWER_OFF))
		save_state = 2;

	cpu_clear_prev_logic_pwrst(cpu);
	set_cpu_next_pwrst(cpu, power_state);
	set_cpu_wakeup_addr(cpu, virt_to_phys(omap4_cpu_resume));
	scu_pwrst_prepare(cpu, power_state);
	l2x0_pwrst_prepare(cpu, save_state);

	/*
	 * Call low level function  with targeted low power state.
	 */
	cpu_suspend(save_state, omap4_finish_suspend);

	/*
	 * Restore the CPUx power state to ON otherwise CPUx
	 * power domain can transitions to programmed low power
	 * state while doing WFI outside the low powe code. On
	 * secure devices, CPUx does WFI which can result in
	 * domain transition
	 */
	wakeup_cpu = smp_processor_id();
	set_cpu_next_pwrst(wakeup_cpu, PWRDM_POWER_ON);

	pwrdm_post_transition(NULL);

	return 0;
}

/**
 * omap4_hotplug_cpu: OMAP4 CPU hotplug entry
 * @cpu : CPU ID
 * @power_state: CPU low power state.
 */
int __cpuinit omap4_hotplug_cpu(unsigned int cpu, unsigned int power_state)
{
	unsigned int cpu_state = 0;

	if (omap_rev() == OMAP4430_REV_ES1_0)
		return -ENXIO;

	if (power_state == PWRDM_POWER_OFF)
		cpu_state = 1;

	clear_cpu_prev_pwrst(cpu);
	set_cpu_next_pwrst(cpu, power_state);
	set_cpu_wakeup_addr(cpu, virt_to_phys(omap_secondary_startup));
	scu_pwrst_prepare(cpu, power_state);

	/*
	 * CPU never retuns back if targeted power state is OFF mode.
	 * CPU ONLINE follows normal CPU ONLINE ptah via
	 * omap_secondary_startup().
	 */
	omap4_finish_suspend(cpu_state);

	set_cpu_next_pwrst(cpu, PWRDM_POWER_ON);
	return 0;
}


/*
 * Initialise OMAP4 MPUSS
 */
int __init omap4_mpuss_init(void)
{
	struct omap4_cpu_pm_info *pm_info;

	if (omap_rev() == OMAP4430_REV_ES1_0) {
		WARN(1, "Power Management not supported on OMAP4430 ES1.0\n");
		return -ENODEV;
	}

	sar_base = omap4_get_sar_ram_base();

	/* Initilaise per CPU PM information */
	pm_info = &per_cpu(omap4_pm_info, 0x0);
	pm_info->scu_sar_addr = sar_base + SCU_OFFSET0;
	pm_info->wkup_sar_addr = sar_base + CPU0_WAKEUP_NS_PA_ADDR_OFFSET;
	pm_info->l2x0_sar_addr = sar_base + L2X0_SAVE_OFFSET0;
	pm_info->pwrdm = pwrdm_lookup("cpu0_pwrdm");
	if (!pm_info->pwrdm) {
		pr_err("Lookup failed for CPU0 pwrdm\n");
		return -ENODEV;
	}

	/* Clear CPU previous power domain state */
	pwrdm_clear_all_prev_pwrst(pm_info->pwrdm);
	cpu_clear_prev_logic_pwrst(0);

	/* Initialise CPU0 power domain state to ON */
	pwrdm_set_next_pwrst(pm_info->pwrdm, PWRDM_POWER_ON);

	pm_info = &per_cpu(omap4_pm_info, 0x1);
	pm_info->scu_sar_addr = sar_base + SCU_OFFSET1;
	pm_info->wkup_sar_addr = sar_base + CPU1_WAKEUP_NS_PA_ADDR_OFFSET;
	pm_info->l2x0_sar_addr = sar_base + L2X0_SAVE_OFFSET1;
	pm_info->pwrdm = pwrdm_lookup("cpu1_pwrdm");
	if (!pm_info->pwrdm) {
		pr_err("Lookup failed for CPU1 pwrdm\n");
		return -ENODEV;
	}

	/* Clear CPU previous power domain state */
	pwrdm_clear_all_prev_pwrst(pm_info->pwrdm);
	cpu_clear_prev_logic_pwrst(1);

	/* Initialise CPU1 power domain state to ON */
	pwrdm_set_next_pwrst(pm_info->pwrdm, PWRDM_POWER_ON);

	mpuss_pd = pwrdm_lookup("mpu_pwrdm");
	if (!mpuss_pd) {
		pr_err("Failed to lookup MPUSS power domain\n");
		return -ENODEV;
	}
	pwrdm_clear_all_prev_pwrst(mpuss_pd);
	mpuss_clear_prev_logic_pwrst();

	/* Save device type on scratchpad for low level code to use */
	if (omap_type() != OMAP2_DEVICE_TYPE_GP)
		__raw_writel(1, sar_base + OMAP_TYPE_OFFSET);
	else
		__raw_writel(0, sar_base + OMAP_TYPE_OFFSET);

	save_l2x0_context();

	return 0;
}

#endif