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64b889b3 MS |
1 | /* |
2 | * Xilinx SLCR driver | |
3 | * | |
4 | * Copyright (c) 2011-2013 Xilinx Inc. | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or | |
7 | * modify it under the terms of the GNU General Public License | |
8 | * as published by the Free Software Foundation; either version | |
9 | * 2 of the License, or (at your option) any later version. | |
10 | * | |
11 | * You should have received a copy of the GNU General Public | |
12 | * License along with this program; if not, write to the Free | |
13 | * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA | |
14 | * 02139, USA. | |
15 | */ | |
16 | ||
64b889b3 | 17 | #include <linux/io.h> |
016f4dca | 18 | #include <linux/mfd/syscon.h> |
64b889b3 | 19 | #include <linux/of_address.h> |
016f4dca | 20 | #include <linux/regmap.h> |
64b889b3 MS |
21 | #include <linux/clk/zynq.h> |
22 | #include "common.h" | |
23 | ||
b5f177ff SB |
24 | /* register offsets */ |
25 | #define SLCR_UNLOCK_OFFSET 0x8 /* SCLR unlock register */ | |
96790f0a | 26 | #define SLCR_PS_RST_CTRL_OFFSET 0x200 /* PS Software Reset Control */ |
b5f177ff SB |
27 | #define SLCR_A9_CPU_RST_CTRL_OFFSET 0x244 /* CPU Software Reset Control */ |
28 | #define SLCR_REBOOT_STATUS_OFFSET 0x258 /* PS Reboot Status */ | |
aa7eb2bb | 29 | |
b5f177ff | 30 | #define SLCR_UNLOCK_MAGIC 0xDF0D |
aa7eb2bb MS |
31 | #define SLCR_A9_CPU_CLKSTOP 0x10 |
32 | #define SLCR_A9_CPU_RST 0x1 | |
33 | ||
7b274efe | 34 | static void __iomem *zynq_slcr_base; |
016f4dca | 35 | static struct regmap *zynq_slcr_regmap; |
64b889b3 | 36 | |
871c6971 MS |
37 | /** |
38 | * zynq_slcr_write - Write to a register in SLCR block | |
39 | * | |
40 | * @val: Value to write to the register | |
41 | * @offset: Register offset in SLCR block | |
42 | * | |
43 | * Return: a negative value on error, 0 on success | |
44 | */ | |
45 | static int zynq_slcr_write(u32 val, u32 offset) | |
46 | { | |
47 | if (!zynq_slcr_regmap) { | |
48 | writel(val, zynq_slcr_base + offset); | |
49 | return 0; | |
50 | } | |
51 | ||
52 | return regmap_write(zynq_slcr_regmap, offset, val); | |
53 | } | |
54 | ||
55 | /** | |
56 | * zynq_slcr_read - Read a register in SLCR block | |
57 | * | |
58 | * @val: Pointer to value to be read from SLCR | |
59 | * @offset: Register offset in SLCR block | |
60 | * | |
61 | * Return: a negative value on error, 0 on success | |
62 | */ | |
63 | static int zynq_slcr_read(u32 *val, u32 offset) | |
64 | { | |
65 | if (zynq_slcr_regmap) | |
66 | return regmap_read(zynq_slcr_regmap, offset, val); | |
67 | ||
68 | *val = readl(zynq_slcr_base + offset); | |
69 | ||
70 | return 0; | |
71 | } | |
72 | ||
56880073 MS |
73 | /** |
74 | * zynq_slcr_unlock - Unlock SLCR registers | |
75 | * | |
76 | * Return: a negative value on error, 0 on success | |
77 | */ | |
78 | static inline int zynq_slcr_unlock(void) | |
79 | { | |
80 | zynq_slcr_write(SLCR_UNLOCK_MAGIC, SLCR_UNLOCK_OFFSET); | |
81 | ||
82 | return 0; | |
83 | } | |
84 | ||
96790f0a MS |
85 | /** |
86 | * zynq_slcr_system_reset - Reset the entire system. | |
87 | */ | |
88 | void zynq_slcr_system_reset(void) | |
89 | { | |
90 | u32 reboot; | |
91 | ||
92 | /* | |
93 | * Unlock the SLCR then reset the system. | |
94 | * Note that this seems to require raw i/o | |
95 | * functions or there's a lockup? | |
96 | */ | |
56880073 | 97 | zynq_slcr_unlock(); |
96790f0a MS |
98 | |
99 | /* | |
100 | * Clear 0x0F000000 bits of reboot status register to workaround | |
101 | * the FSBL not loading the bitstream after soft-reboot | |
102 | * This is a temporary solution until we know more. | |
103 | */ | |
871c6971 MS |
104 | zynq_slcr_read(&reboot, SLCR_REBOOT_STATUS_OFFSET); |
105 | zynq_slcr_write(reboot & 0xF0FFFFFF, SLCR_REBOOT_STATUS_OFFSET); | |
106 | zynq_slcr_write(1, SLCR_PS_RST_CTRL_OFFSET); | |
96790f0a MS |
107 | } |
108 | ||
aa7eb2bb MS |
109 | /** |
110 | * zynq_slcr_cpu_start - Start cpu | |
111 | * @cpu: cpu number | |
112 | */ | |
113 | void zynq_slcr_cpu_start(int cpu) | |
114 | { | |
871c6971 MS |
115 | u32 reg; |
116 | ||
117 | zynq_slcr_read(®, SLCR_A9_CPU_RST_CTRL_OFFSET); | |
3db9e860 | 118 | reg &= ~(SLCR_A9_CPU_RST << cpu); |
871c6971 | 119 | zynq_slcr_write(reg, SLCR_A9_CPU_RST_CTRL_OFFSET); |
3db9e860 | 120 | reg &= ~(SLCR_A9_CPU_CLKSTOP << cpu); |
871c6971 | 121 | zynq_slcr_write(reg, SLCR_A9_CPU_RST_CTRL_OFFSET); |
aa7eb2bb MS |
122 | } |
123 | ||
124 | /** | |
125 | * zynq_slcr_cpu_stop - Stop cpu | |
126 | * @cpu: cpu number | |
127 | */ | |
128 | void zynq_slcr_cpu_stop(int cpu) | |
129 | { | |
871c6971 MS |
130 | u32 reg; |
131 | ||
132 | zynq_slcr_read(®, SLCR_A9_CPU_RST_CTRL_OFFSET); | |
3db9e860 | 133 | reg |= (SLCR_A9_CPU_CLKSTOP | SLCR_A9_CPU_RST) << cpu; |
871c6971 | 134 | zynq_slcr_write(reg, SLCR_A9_CPU_RST_CTRL_OFFSET); |
aa7eb2bb MS |
135 | } |
136 | ||
64b889b3 | 137 | /** |
016f4dca MS |
138 | * zynq_slcr_init - Regular slcr driver init |
139 | * | |
140 | * Return: 0 on success, negative errno otherwise. | |
64b889b3 MS |
141 | * |
142 | * Called early during boot from platform code to remap SLCR area. | |
143 | */ | |
144 | int __init zynq_slcr_init(void) | |
016f4dca MS |
145 | { |
146 | zynq_slcr_regmap = syscon_regmap_lookup_by_compatible("xlnx,zynq-slcr"); | |
147 | if (IS_ERR(zynq_slcr_regmap)) { | |
148 | pr_err("%s: failed to find zynq-slcr\n", __func__); | |
149 | return -ENODEV; | |
150 | } | |
151 | ||
152 | return 0; | |
153 | } | |
154 | ||
155 | /** | |
156 | * zynq_early_slcr_init - Early slcr init function | |
157 | * | |
158 | * Return: 0 on success, negative errno otherwise. | |
159 | * | |
160 | * Called very early during boot from platform code to unlock SLCR. | |
161 | */ | |
162 | int __init zynq_early_slcr_init(void) | |
64b889b3 MS |
163 | { |
164 | struct device_node *np; | |
165 | ||
166 | np = of_find_compatible_node(NULL, NULL, "xlnx,zynq-slcr"); | |
167 | if (!np) { | |
168 | pr_err("%s: no slcr node found\n", __func__); | |
169 | BUG(); | |
170 | } | |
171 | ||
172 | zynq_slcr_base = of_iomap(np, 0); | |
173 | if (!zynq_slcr_base) { | |
174 | pr_err("%s: Unable to map I/O memory\n", __func__); | |
175 | BUG(); | |
176 | } | |
177 | ||
5e218280 ST |
178 | np->data = (__force void *)zynq_slcr_base; |
179 | ||
64b889b3 | 180 | /* unlock the SLCR so that registers can be changed */ |
56880073 | 181 | zynq_slcr_unlock(); |
64b889b3 MS |
182 | |
183 | pr_info("%s mapped to %p\n", np->name, zynq_slcr_base); | |
184 | ||
64b889b3 MS |
185 | of_node_put(np); |
186 | ||
187 | return 0; | |
188 | } |