xref: /openbmc/linux/drivers/clk/at91/pmc.c (revision c997aabb)
1 /*
2  *  Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com>
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation; either version 2 of the License, or
7  * (at your option) any later version.
8  *
9  */
10 
11 #include <linux/clk-provider.h>
12 #include <linux/clkdev.h>
13 #include <linux/clk/at91_pmc.h>
14 #include <linux/of.h>
15 #include <linux/mfd/syscon.h>
16 #include <linux/platform_device.h>
17 #include <linux/regmap.h>
18 #include <linux/syscore_ops.h>
19 
20 #include <asm/proc-fns.h>
21 
22 #include "pmc.h"
23 
24 #define PMC_MAX_IDS 128
25 
26 int of_at91_get_clk_range(struct device_node *np, const char *propname,
27 			  struct clk_range *range)
28 {
29 	u32 min, max;
30 	int ret;
31 
32 	ret = of_property_read_u32_index(np, propname, 0, &min);
33 	if (ret)
34 		return ret;
35 
36 	ret = of_property_read_u32_index(np, propname, 1, &max);
37 	if (ret)
38 		return ret;
39 
40 	if (range) {
41 		range->min = min;
42 		range->max = max;
43 	}
44 
45 	return 0;
46 }
47 EXPORT_SYMBOL_GPL(of_at91_get_clk_range);
48 
49 #ifdef CONFIG_PM
50 static struct regmap *pmcreg;
51 
52 static u8 registered_ids[PMC_MAX_IDS];
53 
54 static struct
55 {
56 	u32 scsr;
57 	u32 pcsr0;
58 	u32 uckr;
59 	u32 mor;
60 	u32 mcfr;
61 	u32 pllar;
62 	u32 mckr;
63 	u32 usb;
64 	u32 imr;
65 	u32 pcsr1;
66 	u32 pcr[PMC_MAX_IDS];
67 	u32 audio_pll0;
68 	u32 audio_pll1;
69 } pmc_cache;
70 
71 void pmc_register_id(u8 id)
72 {
73 	int i;
74 
75 	for (i = 0; i < PMC_MAX_IDS; i++) {
76 		if (registered_ids[i] == 0) {
77 			registered_ids[i] = id;
78 			break;
79 		}
80 		if (registered_ids[i] == id)
81 			break;
82 	}
83 }
84 
85 static int pmc_suspend(void)
86 {
87 	int i;
88 
89 	regmap_read(pmcreg, AT91_PMC_IMR, &pmc_cache.scsr);
90 	regmap_read(pmcreg, AT91_PMC_PCSR, &pmc_cache.pcsr0);
91 	regmap_read(pmcreg, AT91_CKGR_UCKR, &pmc_cache.uckr);
92 	regmap_read(pmcreg, AT91_CKGR_MOR, &pmc_cache.mor);
93 	regmap_read(pmcreg, AT91_CKGR_MCFR, &pmc_cache.mcfr);
94 	regmap_read(pmcreg, AT91_CKGR_PLLAR, &pmc_cache.pllar);
95 	regmap_read(pmcreg, AT91_PMC_MCKR, &pmc_cache.mckr);
96 	regmap_read(pmcreg, AT91_PMC_USB, &pmc_cache.usb);
97 	regmap_read(pmcreg, AT91_PMC_IMR, &pmc_cache.imr);
98 	regmap_read(pmcreg, AT91_PMC_PCSR1, &pmc_cache.pcsr1);
99 
100 	for (i = 0; registered_ids[i]; i++) {
101 		regmap_write(pmcreg, AT91_PMC_PCR,
102 			     (registered_ids[i] & AT91_PMC_PCR_PID_MASK));
103 		regmap_read(pmcreg, AT91_PMC_PCR,
104 			    &pmc_cache.pcr[registered_ids[i]]);
105 	}
106 
107 	return 0;
108 }
109 
110 static void pmc_resume(void)
111 {
112 	int i, ret = 0;
113 	u32 tmp;
114 
115 	regmap_read(pmcreg, AT91_PMC_MCKR, &tmp);
116 	if (pmc_cache.mckr != tmp)
117 		pr_warn("MCKR was not configured properly by the firmware\n");
118 	regmap_read(pmcreg, AT91_CKGR_PLLAR, &tmp);
119 	if (pmc_cache.pllar != tmp)
120 		pr_warn("PLLAR was not configured properly by the firmware\n");
121 
122 	regmap_write(pmcreg, AT91_PMC_IMR, pmc_cache.scsr);
123 	regmap_write(pmcreg, AT91_PMC_PCER, pmc_cache.pcsr0);
124 	regmap_write(pmcreg, AT91_CKGR_UCKR, pmc_cache.uckr);
125 	regmap_write(pmcreg, AT91_CKGR_MOR, pmc_cache.mor);
126 	regmap_write(pmcreg, AT91_CKGR_MCFR, pmc_cache.mcfr);
127 	regmap_write(pmcreg, AT91_PMC_USB, pmc_cache.usb);
128 	regmap_write(pmcreg, AT91_PMC_IMR, pmc_cache.imr);
129 	regmap_write(pmcreg, AT91_PMC_PCER1, pmc_cache.pcsr1);
130 
131 	for (i = 0; registered_ids[i]; i++) {
132 		regmap_write(pmcreg, AT91_PMC_PCR,
133 			     pmc_cache.pcr[registered_ids[i]] |
134 			     AT91_PMC_PCR_CMD);
135 	}
136 
137 	if (pmc_cache.uckr & AT91_PMC_UPLLEN) {
138 		ret = regmap_read_poll_timeout(pmcreg, AT91_PMC_SR, tmp,
139 					       !(tmp & AT91_PMC_LOCKU),
140 					       10, 5000);
141 		if (ret)
142 			pr_crit("USB PLL didn't lock when resuming\n");
143 	}
144 }
145 
146 static struct syscore_ops pmc_syscore_ops = {
147 	.suspend = pmc_suspend,
148 	.resume = pmc_resume,
149 };
150 
151 static const struct of_device_id sama5d2_pmc_dt_ids[] = {
152 	{ .compatible = "atmel,sama5d2-pmc" },
153 	{ /* sentinel */ }
154 };
155 
156 static int __init pmc_register_ops(void)
157 {
158 	struct device_node *np;
159 
160 	np = of_find_matching_node(NULL, sama5d2_pmc_dt_ids);
161 
162 	pmcreg = syscon_node_to_regmap(np);
163 	if (IS_ERR(pmcreg))
164 		return PTR_ERR(pmcreg);
165 
166 	register_syscore_ops(&pmc_syscore_ops);
167 
168 	return 0;
169 }
170 /* This has to happen before arch_initcall because of the tcb_clksrc driver */
171 postcore_initcall(pmc_register_ops);
172 #endif
173