xref: /openbmc/linux/arch/arm/mach-omap2/pm.c (revision ae3473231e77a3f1909d48cd144cebe5e1d049b3)
1 /*
2  * pm.c - Common OMAP2+ power management-related code
3  *
4  * Copyright (C) 2010 Texas Instruments, Inc.
5  * Copyright (C) 2010 Nokia Corporation
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  */
11 
12 #include <linux/kernel.h>
13 #include <linux/init.h>
14 #include <linux/io.h>
15 #include <linux/err.h>
16 #include <linux/pm_opp.h>
17 #include <linux/export.h>
18 #include <linux/suspend.h>
19 #include <linux/cpu.h>
20 
21 #include <asm/system_misc.h>
22 
23 #include "omap-pm.h"
24 #include "omap_device.h"
25 #include "common.h"
26 
27 #include "soc.h"
28 #include "prcm-common.h"
29 #include "voltage.h"
30 #include "powerdomain.h"
31 #include "clockdomain.h"
32 #include "pm.h"
33 
34 #ifdef CONFIG_SUSPEND
35 /*
36  * omap_pm_suspend: points to a function that does the SoC-specific
37  * suspend work
38  */
39 static int (*omap_pm_suspend)(void);
40 #endif
41 
42 #ifdef CONFIG_PM
43 /**
44  * struct omap2_oscillator - Describe the board main oscillator latencies
45  * @startup_time: oscillator startup latency
46  * @shutdown_time: oscillator shutdown latency
47  */
48 struct omap2_oscillator {
49 	u32 startup_time;
50 	u32 shutdown_time;
51 };
52 
53 static struct omap2_oscillator oscillator = {
54 	.startup_time = ULONG_MAX,
55 	.shutdown_time = ULONG_MAX,
56 };
57 
58 void omap_pm_setup_oscillator(u32 tstart, u32 tshut)
59 {
60 	oscillator.startup_time = tstart;
61 	oscillator.shutdown_time = tshut;
62 }
63 
64 void omap_pm_get_oscillator(u32 *tstart, u32 *tshut)
65 {
66 	if (!tstart || !tshut)
67 		return;
68 
69 	*tstart = oscillator.startup_time;
70 	*tshut = oscillator.shutdown_time;
71 }
72 #endif
73 
74 int __init omap_pm_clkdms_setup(struct clockdomain *clkdm, void *unused)
75 {
76 	clkdm_allow_idle(clkdm);
77 	return 0;
78 }
79 
80 /*
81  * This API is to be called during init to set the various voltage
82  * domains to the voltage as per the opp table. Typically we boot up
83  * at the nominal voltage. So this function finds out the rate of
84  * the clock associated with the voltage domain, finds out the correct
85  * opp entry and sets the voltage domain to the voltage specified
86  * in the opp entry
87  */
88 static int __init omap2_set_init_voltage(char *vdd_name, char *clk_name,
89 					 const char *oh_name)
90 {
91 	struct voltagedomain *voltdm;
92 	struct clk *clk;
93 	struct dev_pm_opp *opp;
94 	unsigned long freq, bootup_volt;
95 	struct device *dev;
96 
97 	if (!vdd_name || !clk_name || !oh_name) {
98 		pr_err("%s: invalid parameters\n", __func__);
99 		goto exit;
100 	}
101 
102 	if (!strncmp(oh_name, "mpu", 3))
103 		/*
104 		 * All current OMAPs share voltage rail and clock
105 		 * source, so CPU0 is used to represent the MPU-SS.
106 		 */
107 		dev = get_cpu_device(0);
108 	else
109 		dev = omap_device_get_by_hwmod_name(oh_name);
110 
111 	if (IS_ERR(dev)) {
112 		pr_err("%s: Unable to get dev pointer for hwmod %s\n",
113 			__func__, oh_name);
114 		goto exit;
115 	}
116 
117 	voltdm = voltdm_lookup(vdd_name);
118 	if (!voltdm) {
119 		pr_err("%s: unable to get vdd pointer for vdd_%s\n",
120 			__func__, vdd_name);
121 		goto exit;
122 	}
123 
124 	clk =  clk_get(NULL, clk_name);
125 	if (IS_ERR(clk)) {
126 		pr_err("%s: unable to get clk %s\n", __func__, clk_name);
127 		goto exit;
128 	}
129 
130 	freq = clk_get_rate(clk);
131 	clk_put(clk);
132 
133 	rcu_read_lock();
134 	opp = dev_pm_opp_find_freq_ceil(dev, &freq);
135 	if (IS_ERR(opp)) {
136 		rcu_read_unlock();
137 		pr_err("%s: unable to find boot up OPP for vdd_%s\n",
138 			__func__, vdd_name);
139 		goto exit;
140 	}
141 
142 	bootup_volt = dev_pm_opp_get_voltage(opp);
143 	rcu_read_unlock();
144 	if (!bootup_volt) {
145 		pr_err("%s: unable to find voltage corresponding to the bootup OPP for vdd_%s\n",
146 		       __func__, vdd_name);
147 		goto exit;
148 	}
149 
150 	voltdm_scale(voltdm, bootup_volt);
151 	return 0;
152 
153 exit:
154 	pr_err("%s: unable to set vdd_%s\n", __func__, vdd_name);
155 	return -EINVAL;
156 }
157 
158 #ifdef CONFIG_SUSPEND
159 static int omap_pm_enter(suspend_state_t suspend_state)
160 {
161 	int ret = 0;
162 
163 	if (!omap_pm_suspend)
164 		return -ENOENT; /* XXX doublecheck */
165 
166 	switch (suspend_state) {
167 	case PM_SUSPEND_STANDBY:
168 	case PM_SUSPEND_MEM:
169 		ret = omap_pm_suspend();
170 		break;
171 	default:
172 		ret = -EINVAL;
173 	}
174 
175 	return ret;
176 }
177 
178 static int omap_pm_begin(suspend_state_t state)
179 {
180 	cpu_idle_poll_ctrl(true);
181 	if (soc_is_omap34xx())
182 		omap_prcm_irq_prepare();
183 	return 0;
184 }
185 
186 static void omap_pm_end(void)
187 {
188 	cpu_idle_poll_ctrl(false);
189 }
190 
191 static void omap_pm_finish(void)
192 {
193 	if (soc_is_omap34xx())
194 		omap_prcm_irq_complete();
195 }
196 
197 static const struct platform_suspend_ops omap_pm_ops = {
198 	.begin		= omap_pm_begin,
199 	.end		= omap_pm_end,
200 	.enter		= omap_pm_enter,
201 	.finish		= omap_pm_finish,
202 	.valid		= suspend_valid_only_mem,
203 };
204 
205 /**
206  * omap_common_suspend_init - Set common suspend routines for OMAP SoCs
207  * @pm_suspend: function pointer to SoC specific suspend function
208  */
209 void omap_common_suspend_init(void *pm_suspend)
210 {
211 	omap_pm_suspend = pm_suspend;
212 	suspend_set_ops(&omap_pm_ops);
213 }
214 #endif /* CONFIG_SUSPEND */
215 
216 static void __init omap3_init_voltages(void)
217 {
218 	if (!soc_is_omap34xx())
219 		return;
220 
221 	omap2_set_init_voltage("mpu_iva", "dpll1_ck", "mpu");
222 	omap2_set_init_voltage("core", "l3_ick", "l3_main");
223 }
224 
225 static void __init omap4_init_voltages(void)
226 {
227 	if (!soc_is_omap44xx())
228 		return;
229 
230 	omap2_set_init_voltage("mpu", "dpll_mpu_ck", "mpu");
231 	omap2_set_init_voltage("core", "l3_div_ck", "l3_main_1");
232 	omap2_set_init_voltage("iva", "dpll_iva_m5x2_ck", "iva");
233 }
234 
235 static int __init omap2_common_pm_init(void)
236 {
237 	omap_pm_if_init();
238 
239 	return 0;
240 }
241 omap_postcore_initcall(omap2_common_pm_init);
242 
243 int __init omap2_common_pm_late_init(void)
244 {
245 	/* Init the voltage layer */
246 	omap3_twl_init();
247 	omap4_twl_init();
248 	omap_voltage_late_init();
249 
250 	/* Initialize the voltages */
251 	omap3_init_voltages();
252 	omap4_init_voltages();
253 
254 	/* Smartreflex device init */
255 	omap_devinit_smartreflex();
256 
257 	return 0;
258 }
259