xref: /openbmc/linux/arch/arm/mach-davinci/pm.c (revision cf3c2372)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * DaVinci Power Management Routines
4  *
5  * Copyright (C) 2009 Texas Instruments, Inc. https://www.ti.com/
6  */
7 
8 #include <linux/pm.h>
9 #include <linux/suspend.h>
10 #include <linux/module.h>
11 #include <linux/platform_device.h>
12 #include <linux/clk.h>
13 #include <linux/spinlock.h>
14 
15 #include <asm/cacheflush.h>
16 #include <asm/delay.h>
17 #include <asm/io.h>
18 
19 #include "common.h"
20 #include "da8xx.h"
21 #include "mux.h"
22 #include "pm.h"
23 #include "clock.h"
24 #include "psc.h"
25 #include "sram.h"
26 
27 #define DA850_PLL1_BASE		0x01e1a000
28 #define DEEPSLEEP_SLEEPCOUNT_MASK	0xFFFF
29 #define DEEPSLEEP_SLEEPCOUNT		128
30 
31 static void (*davinci_sram_suspend) (struct davinci_pm_config *);
32 static struct davinci_pm_config pm_config = {
33 	.sleepcount = DEEPSLEEP_SLEEPCOUNT,
34 	.ddrpsc_num = DA8XX_LPSC1_EMIF3C,
35 };
36 
davinci_sram_push(void * dest,void * src,unsigned int size)37 static void davinci_sram_push(void *dest, void *src, unsigned int size)
38 {
39 	memcpy(dest, src, size);
40 	flush_icache_range((unsigned long)dest, (unsigned long)(dest + size));
41 }
42 
davinci_pm_suspend(void)43 static void davinci_pm_suspend(void)
44 {
45 	unsigned val;
46 
47 	if (pm_config.cpupll_reg_base != pm_config.ddrpll_reg_base) {
48 
49 		/* Switch CPU PLL to bypass mode */
50 		val = __raw_readl(pm_config.cpupll_reg_base + PLLCTL);
51 		val &= ~(PLLCTL_PLLENSRC | PLLCTL_PLLEN);
52 		__raw_writel(val, pm_config.cpupll_reg_base + PLLCTL);
53 
54 		udelay(PLL_BYPASS_TIME);
55 
56 		/* Powerdown CPU PLL */
57 		val = __raw_readl(pm_config.cpupll_reg_base + PLLCTL);
58 		val |= PLLCTL_PLLPWRDN;
59 		__raw_writel(val, pm_config.cpupll_reg_base + PLLCTL);
60 	}
61 
62 	/* Configure sleep count in deep sleep register */
63 	val = __raw_readl(pm_config.deepsleep_reg);
64 	val &= ~DEEPSLEEP_SLEEPCOUNT_MASK;
65 	val |= pm_config.sleepcount;
66 	__raw_writel(val, pm_config.deepsleep_reg);
67 
68 	/* System goes to sleep in this call */
69 	davinci_sram_suspend(&pm_config);
70 
71 	if (pm_config.cpupll_reg_base != pm_config.ddrpll_reg_base) {
72 
73 		/* put CPU PLL in reset */
74 		val = __raw_readl(pm_config.cpupll_reg_base + PLLCTL);
75 		val &= ~PLLCTL_PLLRST;
76 		__raw_writel(val, pm_config.cpupll_reg_base + PLLCTL);
77 
78 		/* put CPU PLL in power down */
79 		val = __raw_readl(pm_config.cpupll_reg_base + PLLCTL);
80 		val &= ~PLLCTL_PLLPWRDN;
81 		__raw_writel(val, pm_config.cpupll_reg_base + PLLCTL);
82 
83 		/* wait for CPU PLL reset */
84 		udelay(PLL_RESET_TIME);
85 
86 		/* bring CPU PLL out of reset */
87 		val = __raw_readl(pm_config.cpupll_reg_base + PLLCTL);
88 		val |= PLLCTL_PLLRST;
89 		__raw_writel(val, pm_config.cpupll_reg_base + PLLCTL);
90 
91 		/* Wait for CPU PLL to lock */
92 		udelay(PLL_LOCK_TIME);
93 
94 		/* Remove CPU PLL from bypass mode */
95 		val = __raw_readl(pm_config.cpupll_reg_base + PLLCTL);
96 		val &= ~PLLCTL_PLLENSRC;
97 		val |= PLLCTL_PLLEN;
98 		__raw_writel(val, pm_config.cpupll_reg_base + PLLCTL);
99 	}
100 }
101 
davinci_pm_enter(suspend_state_t state)102 static int davinci_pm_enter(suspend_state_t state)
103 {
104 	int ret = 0;
105 
106 	switch (state) {
107 	case PM_SUSPEND_MEM:
108 		davinci_pm_suspend();
109 		break;
110 	default:
111 		ret = -EINVAL;
112 	}
113 
114 	return ret;
115 }
116 
117 static const struct platform_suspend_ops davinci_pm_ops = {
118 	.enter		= davinci_pm_enter,
119 	.valid		= suspend_valid_only_mem,
120 };
121 
davinci_pm_init(void)122 int __init davinci_pm_init(void)
123 {
124 	int ret;
125 
126 	ret = davinci_cfg_reg(DA850_RTC_ALARM);
127 	if (ret)
128 		return ret;
129 
130 	pm_config.ddr2_ctlr_base = da8xx_get_mem_ctlr();
131 	pm_config.deepsleep_reg = DA8XX_SYSCFG1_VIRT(DA8XX_DEEPSLEEP_REG);
132 
133 	pm_config.cpupll_reg_base = ioremap(DA8XX_PLL0_BASE, SZ_4K);
134 	if (!pm_config.cpupll_reg_base)
135 		return -ENOMEM;
136 
137 	pm_config.ddrpll_reg_base = ioremap(DA850_PLL1_BASE, SZ_4K);
138 	if (!pm_config.ddrpll_reg_base) {
139 		ret = -ENOMEM;
140 		goto no_ddrpll_mem;
141 	}
142 
143 	pm_config.ddrpsc_reg_base = ioremap(DA8XX_PSC1_BASE, SZ_4K);
144 	if (!pm_config.ddrpsc_reg_base) {
145 		ret = -ENOMEM;
146 		goto no_ddrpsc_mem;
147 	}
148 
149 	davinci_sram_suspend = sram_alloc(davinci_cpu_suspend_sz, NULL);
150 	if (!davinci_sram_suspend) {
151 		pr_err("PM: cannot allocate SRAM memory\n");
152 		ret = -ENOMEM;
153 		goto no_sram_mem;
154 	}
155 
156 	davinci_sram_push(davinci_sram_suspend, davinci_cpu_suspend,
157 						davinci_cpu_suspend_sz);
158 
159 	suspend_set_ops(&davinci_pm_ops);
160 
161 	return 0;
162 
163 no_sram_mem:
164 	iounmap(pm_config.ddrpsc_reg_base);
165 no_ddrpsc_mem:
166 	iounmap(pm_config.ddrpll_reg_base);
167 no_ddrpll_mem:
168 	iounmap(pm_config.cpupll_reg_base);
169 	return ret;
170 }
171