summaryrefslogtreecommitdiffstats
path: root/arch/arm/mach-imx/pm-imx5.c
blob: 19621ed1ffa5852900e2ab285e3ea1c2b4c1c357 (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
/*
 *  Copyright (C) 2011 Freescale Semiconductor, Inc. All Rights Reserved.
 *
 * The code contained herein is licensed under the GNU General Public
 * License. You may obtain a copy of the GNU General Public License
 * Version 2 or later at the following locations:
 *
 * http://www.opensource.org/licenses/gpl-license.html
 * http://www.gnu.org/copyleft/gpl.html
 */
#include <linux/suspend.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/err.h>
#include <linux/export.h>
#include <asm/cacheflush.h>
#include <asm/system_misc.h>
#include <asm/tlbflush.h>
#include <mach/common.h>
#include <mach/cpuidle.h>
#include <mach/hardware.h>
#include "crm-regs-imx5.h"

/*
 * The WAIT_UNCLOCKED_POWER_OFF state only requires <= 500ns to exit.
 * This is also the lowest power state possible without affecting
 * non-cpu parts of the system.  For these reasons, imx5 should default
 * to always using this state for cpu idling.  The PM_SUSPEND_STANDBY also
 * uses this state and needs to take no action when registers remain confgiured
 * for this state.
 */
#define IMX5_DEFAULT_CPU_IDLE_STATE WAIT_UNCLOCKED_POWER_OFF

/*
 * set cpu low power mode before WFI instruction. This function is called
 * mx5 because it can be used for mx50, mx51, and mx53.
 */
static void mx5_cpu_lp_set(enum mxc_cpu_pwr_mode mode)
{
	u32 plat_lpc, arm_srpgcr, ccm_clpcr;
	u32 empgc0, empgc1;
	int stop_mode = 0;

	/* always allow platform to issue a deep sleep mode request */
	plat_lpc = __raw_readl(MXC_CORTEXA8_PLAT_LPC) &
	    ~(MXC_CORTEXA8_PLAT_LPC_DSM);
	ccm_clpcr = __raw_readl(MXC_CCM_CLPCR) & ~(MXC_CCM_CLPCR_LPM_MASK);
	arm_srpgcr = __raw_readl(MXC_SRPG_ARM_SRPGCR) & ~(MXC_SRPGCR_PCR);
	empgc0 = __raw_readl(MXC_SRPG_EMPGC0_SRPGCR) & ~(MXC_SRPGCR_PCR);
	empgc1 = __raw_readl(MXC_SRPG_EMPGC1_SRPGCR) & ~(MXC_SRPGCR_PCR);

	switch (mode) {
	case WAIT_CLOCKED:
		break;
	case WAIT_UNCLOCKED:
		ccm_clpcr |= 0x1 << MXC_CCM_CLPCR_LPM_OFFSET;
		break;
	case WAIT_UNCLOCKED_POWER_OFF:
	case STOP_POWER_OFF:
		plat_lpc |= MXC_CORTEXA8_PLAT_LPC_DSM
			    | MXC_CORTEXA8_PLAT_LPC_DBG_DSM;
		if (mode == WAIT_UNCLOCKED_POWER_OFF) {
			ccm_clpcr |= 0x1 << MXC_CCM_CLPCR_LPM_OFFSET;
			ccm_clpcr &= ~MXC_CCM_CLPCR_VSTBY;
			ccm_clpcr &= ~MXC_CCM_CLPCR_SBYOS;
			stop_mode = 0;
		} else {
			ccm_clpcr |= 0x2 << MXC_CCM_CLPCR_LPM_OFFSET;
			ccm_clpcr |= 0x3 << MXC_CCM_CLPCR_STBY_COUNT_OFFSET;
			ccm_clpcr |= MXC_CCM_CLPCR_VSTBY;
			ccm_clpcr |= MXC_CCM_CLPCR_SBYOS;
			stop_mode = 1;
		}
		arm_srpgcr |= MXC_SRPGCR_PCR;
		break;
	case STOP_POWER_ON:
		ccm_clpcr |= 0x2 << MXC_CCM_CLPCR_LPM_OFFSET;
		break;
	default:
		printk(KERN_WARNING "UNKNOWN cpu power mode: %d\n", mode);
		return;
	}

	__raw_writel(plat_lpc, MXC_CORTEXA8_PLAT_LPC);
	__raw_writel(ccm_clpcr, MXC_CCM_CLPCR);
	__raw_writel(arm_srpgcr, MXC_SRPG_ARM_SRPGCR);

	/* Enable NEON SRPG for all but MX50TO1.0. */
	if (mx50_revision() != IMX_CHIP_REVISION_1_0)
		__raw_writel(arm_srpgcr, MXC_SRPG_NEON_SRPGCR);

	if (stop_mode) {
		empgc0 |= MXC_SRPGCR_PCR;
		empgc1 |= MXC_SRPGCR_PCR;

		__raw_writel(empgc0, MXC_SRPG_EMPGC0_SRPGCR);
		__raw_writel(empgc1, MXC_SRPG_EMPGC1_SRPGCR);
	}
}

static int mx5_suspend_enter(suspend_state_t state)
{
	switch (state) {
	case PM_SUSPEND_MEM:
		mx5_cpu_lp_set(STOP_POWER_OFF);
		break;
	case PM_SUSPEND_STANDBY:
		/* DEFAULT_IDLE_STATE already configured */
		break;
	default:
		return -EINVAL;
	}

	if (state == PM_SUSPEND_MEM) {
		local_flush_tlb_all();
		flush_cache_all();

		/*clear the EMPGC0/1 bits */
		__raw_writel(0, MXC_SRPG_EMPGC0_SRPGCR);
		__raw_writel(0, MXC_SRPG_EMPGC1_SRPGCR);
	}
	cpu_do_idle();

	/* return registers to default idle state */
	mx5_cpu_lp_set(IMX5_DEFAULT_CPU_IDLE_STATE);
	return 0;
}

static int mx5_pm_valid(suspend_state_t state)
{
	return (state > PM_SUSPEND_ON && state <= PM_SUSPEND_MAX);
}

static const struct platform_suspend_ops mx5_suspend_ops = {
	.valid = mx5_pm_valid,
	.enter = mx5_suspend_enter,
};

static inline int imx5_cpu_do_idle(void)
{
	int ret = tzic_enable_wake();

	if (likely(!ret))
		cpu_do_idle();

	return ret;
}

static void imx5_pm_idle(void)
{
	imx5_cpu_do_idle();
}

static int imx5_cpuidle_enter(struct cpuidle_device *dev,
				struct cpuidle_driver *drv, int idx)
{
	int ret;

	ret = imx5_cpu_do_idle();
	if (ret < 0)
		return ret;

	return idx;
}

static struct cpuidle_driver imx5_cpuidle_driver = {
	.name			= "imx5_cpuidle",
	.owner			= THIS_MODULE,
	.en_core_tk_irqen	= 1,
	.states[0]	= {
		.enter			= imx5_cpuidle_enter,
		.exit_latency		= 2,
		.target_residency	= 1,
		.flags			= CPUIDLE_FLAG_TIME_VALID,
		.name			= "IMX5 SRPG",
		.desc			= "CPU state retained,powered off",
	},
	.state_count		= 1,
};

static int __init imx5_pm_common_init(void)
{
	int ret;
	struct clk *gpc_dvfs_clk = clk_get(NULL, "gpc_dvfs");

	if (IS_ERR(gpc_dvfs_clk))
		return PTR_ERR(gpc_dvfs_clk);

	ret = clk_prepare_enable(gpc_dvfs_clk);
	if (ret)
		return ret;

	arm_pm_idle = imx5_pm_idle;

	/* Set the registers to the default cpu idle state. */
	mx5_cpu_lp_set(IMX5_DEFAULT_CPU_IDLE_STATE);

	imx_cpuidle_init(&imx5_cpuidle_driver);
	return 0;
}

void __init imx51_pm_init(void)
{
	int ret = imx5_pm_common_init();
	if (!ret)
		suspend_set_ops(&mx5_suspend_ops);
}

void __init imx53_pm_init(void)
{
	imx5_pm_common_init();
}