xref: /openbmc/linux/arch/arm/mach-omap2/pm44xx.c (revision fb574682)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * OMAP4+ Power Management Routines
4  *
5  * Copyright (C) 2010-2013 Texas Instruments, Inc.
6  * Rajendra Nayak <rnayak@ti.com>
7  * Santosh Shilimkar <santosh.shilimkar@ti.com>
8  */
9 
10 #include <linux/pm.h>
11 #include <linux/suspend.h>
12 #include <linux/module.h>
13 #include <linux/list.h>
14 #include <linux/err.h>
15 #include <linux/slab.h>
16 #include <asm/system_misc.h>
17 
18 #include "soc.h"
19 #include "common.h"
20 #include "clockdomain.h"
21 #include "powerdomain.h"
22 #include "pm.h"
23 
24 u16 pm44xx_errata;
25 
26 struct power_state {
27 	struct powerdomain *pwrdm;
28 	u32 next_state;
29 	u32 next_logic_state;
30 #ifdef CONFIG_SUSPEND
31 	u32 saved_state;
32 	u32 saved_logic_state;
33 #endif
34 	struct list_head node;
35 };
36 
37 /**
38  * struct static_dep_map - Static dependency map
39  * @from:	from clockdomain
40  * @to:		to clockdomain
41   */
42 struct static_dep_map {
43 	const char *from;
44 	const char *to;
45 };
46 
47 static u32 cpu_suspend_state = PWRDM_POWER_OFF;
48 
49 static LIST_HEAD(pwrst_list);
50 
51 #ifdef CONFIG_SUSPEND
52 static int omap4_pm_suspend(void)
53 {
54 	struct power_state *pwrst;
55 	int state, ret = 0;
56 	u32 cpu_id = smp_processor_id();
57 
58 	/* Save current powerdomain state */
59 	list_for_each_entry(pwrst, &pwrst_list, node) {
60 		pwrst->saved_state = pwrdm_read_next_pwrst(pwrst->pwrdm);
61 		pwrst->saved_logic_state = pwrdm_read_logic_retst(pwrst->pwrdm);
62 	}
63 
64 	/* Set targeted power domain states by suspend */
65 	list_for_each_entry(pwrst, &pwrst_list, node) {
66 		omap_set_pwrdm_state(pwrst->pwrdm, pwrst->next_state);
67 		pwrdm_set_logic_retst(pwrst->pwrdm, pwrst->next_logic_state);
68 	}
69 
70 	/*
71 	 * For MPUSS to hit power domain retention(CSWR or OSWR),
72 	 * CPU0 and CPU1 power domains need to be in OFF or DORMANT state,
73 	 * since CPU power domain CSWR is not supported by hardware
74 	 * Only master CPU follows suspend path. All other CPUs follow
75 	 * CPU hotplug path in system wide suspend. On OMAP4, CPU power
76 	 * domain CSWR is not supported by hardware.
77 	 * More details can be found in OMAP4430 TRM section 4.3.4.2.
78 	 */
79 	omap4_enter_lowpower(cpu_id, cpu_suspend_state);
80 
81 	/* Restore next powerdomain state */
82 	list_for_each_entry(pwrst, &pwrst_list, node) {
83 		state = pwrdm_read_prev_pwrst(pwrst->pwrdm);
84 		if (state > pwrst->next_state) {
85 			pr_info("Powerdomain (%s) didn't enter target state %d\n",
86 				pwrst->pwrdm->name, pwrst->next_state);
87 			ret = -1;
88 		}
89 		omap_set_pwrdm_state(pwrst->pwrdm, pwrst->saved_state);
90 		pwrdm_set_logic_retst(pwrst->pwrdm, pwrst->saved_logic_state);
91 	}
92 	if (ret) {
93 		pr_crit("Could not enter target state in pm_suspend\n");
94 		/*
95 		 * OMAP4 chip PM currently works only with certain (newer)
96 		 * versions of bootloaders. This is due to missing code in the
97 		 * kernel to properly reset and initialize some devices.
98 		 * Warn the user about the bootloader version being one of the
99 		 * possible causes.
100 		 * http://www.spinics.net/lists/arm-kernel/msg218641.html
101 		 */
102 		pr_warn("A possible cause could be an old bootloader - try u-boot >= v2012.07\n");
103 	} else {
104 		pr_info("Successfully put all powerdomains to target state\n");
105 	}
106 
107 	return 0;
108 }
109 #else
110 #define omap4_pm_suspend NULL
111 #endif /* CONFIG_SUSPEND */
112 
113 static int __init pwrdms_setup(struct powerdomain *pwrdm, void *unused)
114 {
115 	struct power_state *pwrst;
116 
117 	if (!pwrdm->pwrsts)
118 		return 0;
119 
120 	/*
121 	 * Skip CPU0 and CPU1 power domains. CPU1 is programmed
122 	 * through hotplug path and CPU0 explicitly programmed
123 	 * further down in the code path
124 	 */
125 	if (!strncmp(pwrdm->name, "cpu", 3)) {
126 		if (IS_PM44XX_ERRATUM(PM_OMAP4_CPU_OSWR_DISABLE))
127 			cpu_suspend_state = PWRDM_POWER_RET;
128 		return 0;
129 	}
130 
131 	if (!strncmp(pwrdm->name, "core", 4) ||
132 	    !strncmp(pwrdm->name, "l4per", 5))
133 		pwrdm_set_logic_retst(pwrdm, PWRDM_POWER_OFF);
134 
135 	pwrst = kmalloc(sizeof(struct power_state), GFP_ATOMIC);
136 	if (!pwrst)
137 		return -ENOMEM;
138 
139 	pwrst->pwrdm = pwrdm;
140 	pwrst->next_state = pwrdm_get_valid_lp_state(pwrdm, false,
141 						     PWRDM_POWER_RET);
142 	pwrst->next_logic_state = pwrdm_get_valid_lp_state(pwrdm, true,
143 							   PWRDM_POWER_OFF);
144 
145 	list_add(&pwrst->node, &pwrst_list);
146 
147 	return omap_set_pwrdm_state(pwrst->pwrdm, pwrst->next_state);
148 }
149 
150 /**
151  * omap_default_idle - OMAP4 default ilde routine.'
152  *
153  * Implements OMAP4 memory, IO ordering requirements which can't be addressed
154  * with default cpu_do_idle() hook. Used by all CPUs with !CONFIG_CPU_IDLE and
155  * by secondary CPU with CONFIG_CPU_IDLE.
156  */
157 static void omap_default_idle(void)
158 {
159 	omap_do_wfi();
160 }
161 
162 /*
163  * The dynamic dependency between MPUSS -> MEMIF and
164  * MPUSS -> L4_PER/L3_* and DUCATI -> L3_* doesn't work as
165  * expected. The hardware recommendation is to enable static
166  * dependencies for these to avoid system lock ups or random crashes.
167  * The L4 wakeup depedency is added to workaround the OCP sync hardware
168  * BUG with 32K synctimer which lead to incorrect timer value read
169  * from the 32K counter. The BUG applies for GPTIMER1 and WDT2 which
170  * are part of L4 wakeup clockdomain.
171  */
172 static const struct static_dep_map omap4_static_dep_map[] = {
173 	{.from = "mpuss_clkdm", .to = "l3_emif_clkdm"},
174 	{.from = "mpuss_clkdm", .to = "l3_1_clkdm"},
175 	{.from = "mpuss_clkdm", .to = "l3_2_clkdm"},
176 	{.from = "ducati_clkdm", .to = "l3_1_clkdm"},
177 	{.from = "ducati_clkdm", .to = "l3_2_clkdm"},
178 	{.from  = NULL} /* TERMINATION */
179 };
180 
181 static const struct static_dep_map omap5_dra7_static_dep_map[] = {
182 	{.from = "mpu_clkdm", .to = "emif_clkdm"},
183 	{.from  = NULL} /* TERMINATION */
184 };
185 
186 /**
187  * omap4plus_init_static_deps() - Initialize a static dependency map
188  * @map:	Mapping of clock domains
189  */
190 static inline int omap4plus_init_static_deps(const struct static_dep_map *map)
191 {
192 	int ret;
193 	struct clockdomain *from, *to;
194 
195 	if (!map)
196 		return 0;
197 
198 	while (map->from) {
199 		from = clkdm_lookup(map->from);
200 		to = clkdm_lookup(map->to);
201 		if (!from || !to) {
202 			pr_err("Failed lookup %s or %s for wakeup dependency\n",
203 			       map->from, map->to);
204 			return -EINVAL;
205 		}
206 		ret = clkdm_add_wkdep(from, to);
207 		if (ret) {
208 			pr_err("Failed to add %s -> %s wakeup dependency(%d)\n",
209 			       map->from, map->to, ret);
210 			return ret;
211 		}
212 
213 		map++;
214 	}
215 
216 	return 0;
217 }
218 
219 /**
220  * omap4_pm_init_early - Does early initialization necessary for OMAP4+ devices
221  *
222  * Initializes basic stuff for power management functionality.
223  */
224 int __init omap4_pm_init_early(void)
225 {
226 	if (cpu_is_omap446x())
227 		pm44xx_errata |= PM_OMAP4_ROM_SMP_BOOT_ERRATUM_GICD;
228 
229 	if (soc_is_omap54xx() || soc_is_dra7xx())
230 		pm44xx_errata |= PM_OMAP4_CPU_OSWR_DISABLE;
231 
232 	return 0;
233 }
234 
235 /**
236  * omap4_pm_init - Init routine for OMAP4+ devices
237  *
238  * Initializes all powerdomain and clockdomain target states
239  * and all PRCM settings.
240  * Return: Returns the error code returned by called functions.
241  */
242 int __init omap4_pm_init(void)
243 {
244 	int ret = 0;
245 
246 	if (omap_rev() == OMAP4430_REV_ES1_0) {
247 		WARN(1, "Power Management not supported on OMAP4430 ES1.0\n");
248 		return -ENODEV;
249 	}
250 
251 	pr_info("Power Management for TI OMAP4+ devices.\n");
252 
253 	/*
254 	 * OMAP4 chip PM currently works only with certain (newer)
255 	 * versions of bootloaders. This is due to missing code in the
256 	 * kernel to properly reset and initialize some devices.
257 	 * http://www.spinics.net/lists/arm-kernel/msg218641.html
258 	 */
259 	if (cpu_is_omap44xx())
260 		pr_warn("OMAP4 PM: u-boot >= v2012.07 is required for full PM support\n");
261 
262 	ret = pwrdm_for_each(pwrdms_setup, NULL);
263 	if (ret) {
264 		pr_err("Failed to setup powerdomains.\n");
265 		goto err2;
266 	}
267 
268 	if (cpu_is_omap44xx())
269 		ret = omap4plus_init_static_deps(omap4_static_dep_map);
270 	else if (soc_is_omap54xx() || soc_is_dra7xx())
271 		ret = omap4plus_init_static_deps(omap5_dra7_static_dep_map);
272 
273 	if (ret) {
274 		pr_err("Failed to initialise static dependencies.\n");
275 		goto err2;
276 	}
277 
278 	ret = omap4_mpuss_init();
279 	if (ret) {
280 		pr_err("Failed to initialise OMAP4 MPUSS\n");
281 		goto err2;
282 	}
283 
284 	(void) clkdm_for_each(omap_pm_clkdms_setup, NULL);
285 
286 	omap_common_suspend_init(omap4_pm_suspend);
287 
288 	/* Overwrite the default cpu_do_idle() */
289 	arm_pm_idle = omap_default_idle;
290 
291 	if (cpu_is_omap44xx() || soc_is_omap54xx())
292 		omap4_idle_init();
293 
294 err2:
295 	return ret;
296 }
297