xref: /openbmc/linux/arch/arm/mach-omap2/pm44xx.c (revision b6bec26c)
1 /*
2  * OMAP4 Power Management Routines
3  *
4  * Copyright (C) 2010-2011 Texas Instruments, Inc.
5  * Rajendra Nayak <rnayak@ti.com>
6  * Santosh Shilimkar <santosh.shilimkar@ti.com>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License version 2 as
10  * published by the Free Software Foundation.
11  */
12 
13 #include <linux/pm.h>
14 #include <linux/suspend.h>
15 #include <linux/module.h>
16 #include <linux/list.h>
17 #include <linux/err.h>
18 #include <linux/slab.h>
19 #include <asm/system_misc.h>
20 
21 #include "soc.h"
22 #include "common.h"
23 #include "clockdomain.h"
24 #include "powerdomain.h"
25 #include "pm.h"
26 
27 struct power_state {
28 	struct powerdomain *pwrdm;
29 	u32 next_state;
30 #ifdef CONFIG_SUSPEND
31 	u32 saved_state;
32 	u32 saved_logic_state;
33 #endif
34 	struct list_head node;
35 };
36 
37 static LIST_HEAD(pwrst_list);
38 
39 #ifdef CONFIG_SUSPEND
40 static int omap4_pm_suspend(void)
41 {
42 	struct power_state *pwrst;
43 	int state, ret = 0;
44 	u32 cpu_id = smp_processor_id();
45 
46 	/* Save current powerdomain state */
47 	list_for_each_entry(pwrst, &pwrst_list, node) {
48 		pwrst->saved_state = pwrdm_read_next_pwrst(pwrst->pwrdm);
49 		pwrst->saved_logic_state = pwrdm_read_logic_retst(pwrst->pwrdm);
50 	}
51 
52 	/* Set targeted power domain states by suspend */
53 	list_for_each_entry(pwrst, &pwrst_list, node) {
54 		omap_set_pwrdm_state(pwrst->pwrdm, pwrst->next_state);
55 		pwrdm_set_logic_retst(pwrst->pwrdm, PWRDM_POWER_OFF);
56 	}
57 
58 	/*
59 	 * For MPUSS to hit power domain retention(CSWR or OSWR),
60 	 * CPU0 and CPU1 power domains need to be in OFF or DORMANT state,
61 	 * since CPU power domain CSWR is not supported by hardware
62 	 * Only master CPU follows suspend path. All other CPUs follow
63 	 * CPU hotplug path in system wide suspend. On OMAP4, CPU power
64 	 * domain CSWR is not supported by hardware.
65 	 * More details can be found in OMAP4430 TRM section 4.3.4.2.
66 	 */
67 	omap4_enter_lowpower(cpu_id, PWRDM_POWER_OFF);
68 
69 	/* Restore next powerdomain state */
70 	list_for_each_entry(pwrst, &pwrst_list, node) {
71 		state = pwrdm_read_prev_pwrst(pwrst->pwrdm);
72 		if (state > pwrst->next_state) {
73 			pr_info("Powerdomain (%s) didn't enter target state %d\n",
74 				pwrst->pwrdm->name, pwrst->next_state);
75 			ret = -1;
76 		}
77 		omap_set_pwrdm_state(pwrst->pwrdm, pwrst->saved_state);
78 		pwrdm_set_logic_retst(pwrst->pwrdm, pwrst->saved_logic_state);
79 	}
80 	if (ret)
81 		pr_crit("Could not enter target state in pm_suspend\n");
82 	else
83 		pr_info("Successfully put all powerdomains to target state\n");
84 
85 	return 0;
86 }
87 #endif /* CONFIG_SUSPEND */
88 
89 static int __init pwrdms_setup(struct powerdomain *pwrdm, void *unused)
90 {
91 	struct power_state *pwrst;
92 
93 	if (!pwrdm->pwrsts)
94 		return 0;
95 
96 	/*
97 	 * Skip CPU0 and CPU1 power domains. CPU1 is programmed
98 	 * through hotplug path and CPU0 explicitly programmed
99 	 * further down in the code path
100 	 */
101 	if (!strncmp(pwrdm->name, "cpu", 3))
102 		return 0;
103 
104 	pwrst = kmalloc(sizeof(struct power_state), GFP_ATOMIC);
105 	if (!pwrst)
106 		return -ENOMEM;
107 
108 	pwrst->pwrdm = pwrdm;
109 	pwrst->next_state = PWRDM_POWER_RET;
110 	list_add(&pwrst->node, &pwrst_list);
111 
112 	return omap_set_pwrdm_state(pwrst->pwrdm, pwrst->next_state);
113 }
114 
115 /**
116  * omap_default_idle - OMAP4 default ilde routine.'
117  *
118  * Implements OMAP4 memory, IO ordering requirements which can't be addressed
119  * with default cpu_do_idle() hook. Used by all CPUs with !CONFIG_CPUIDLE and
120  * by secondary CPU with CONFIG_CPUIDLE.
121  */
122 static void omap_default_idle(void)
123 {
124 	local_fiq_disable();
125 
126 	omap_do_wfi();
127 
128 	local_fiq_enable();
129 }
130 
131 /**
132  * omap4_pm_init - Init routine for OMAP4 PM
133  *
134  * Initializes all powerdomain and clockdomain target states
135  * and all PRCM settings.
136  */
137 int __init omap4_pm_init(void)
138 {
139 	int ret;
140 	struct clockdomain *emif_clkdm, *mpuss_clkdm, *l3_1_clkdm, *l4wkup;
141 	struct clockdomain *ducati_clkdm, *l3_2_clkdm, *l4_per_clkdm;
142 
143 	if (omap_rev() == OMAP4430_REV_ES1_0) {
144 		WARN(1, "Power Management not supported on OMAP4430 ES1.0\n");
145 		return -ENODEV;
146 	}
147 
148 	pr_err("Power Management for TI OMAP4.\n");
149 
150 	ret = pwrdm_for_each(pwrdms_setup, NULL);
151 	if (ret) {
152 		pr_err("Failed to setup powerdomains\n");
153 		goto err2;
154 	}
155 
156 	/*
157 	 * The dynamic dependency between MPUSS -> MEMIF and
158 	 * MPUSS -> L4_PER/L3_* and DUCATI -> L3_* doesn't work as
159 	 * expected. The hardware recommendation is to enable static
160 	 * dependencies for these to avoid system lock ups or random crashes.
161 	 * The L4 wakeup depedency is added to workaround the OCP sync hardware
162 	 * BUG with 32K synctimer which lead to incorrect timer value read
163 	 * from the 32K counter. The BUG applies for GPTIMER1 and WDT2 which
164 	 * are part of L4 wakeup clockdomain.
165 	 */
166 	mpuss_clkdm = clkdm_lookup("mpuss_clkdm");
167 	emif_clkdm = clkdm_lookup("l3_emif_clkdm");
168 	l3_1_clkdm = clkdm_lookup("l3_1_clkdm");
169 	l3_2_clkdm = clkdm_lookup("l3_2_clkdm");
170 	l4_per_clkdm = clkdm_lookup("l4_per_clkdm");
171 	l4wkup = clkdm_lookup("l4_wkup_clkdm");
172 	ducati_clkdm = clkdm_lookup("ducati_clkdm");
173 	if ((!mpuss_clkdm) || (!emif_clkdm) || (!l3_1_clkdm) || (!l4wkup) ||
174 		(!l3_2_clkdm) || (!ducati_clkdm) || (!l4_per_clkdm))
175 		goto err2;
176 
177 	ret = clkdm_add_wkdep(mpuss_clkdm, emif_clkdm);
178 	ret |= clkdm_add_wkdep(mpuss_clkdm, l3_1_clkdm);
179 	ret |= clkdm_add_wkdep(mpuss_clkdm, l3_2_clkdm);
180 	ret |= clkdm_add_wkdep(mpuss_clkdm, l4_per_clkdm);
181 	ret |= clkdm_add_wkdep(mpuss_clkdm, l4wkup);
182 	ret |= clkdm_add_wkdep(ducati_clkdm, l3_1_clkdm);
183 	ret |= clkdm_add_wkdep(ducati_clkdm, l3_2_clkdm);
184 	if (ret) {
185 		pr_err("Failed to add MPUSS -> L3/EMIF/L4PER, DUCATI -> L3 wakeup dependency\n");
186 		goto err2;
187 	}
188 
189 	ret = omap4_mpuss_init();
190 	if (ret) {
191 		pr_err("Failed to initialise OMAP4 MPUSS\n");
192 		goto err2;
193 	}
194 
195 	(void) clkdm_for_each(omap_pm_clkdms_setup, NULL);
196 
197 #ifdef CONFIG_SUSPEND
198 	omap_pm_suspend = omap4_pm_suspend;
199 #endif
200 
201 	/* Overwrite the default cpu_do_idle() */
202 	arm_pm_idle = omap_default_idle;
203 
204 	omap4_idle_init();
205 
206 err2:
207 	return ret;
208 }
209