Commit | Line | Data |
---|---|---|
16a624a9 SH |
1 | /* |
2 | * Copyright (c) 2015 Pengutronix, Sascha Hauer <kernel@pengutronix.de> | |
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 version 2 as | |
6 | * published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, | |
9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
11 | * GNU General Public License for more details. | |
12 | */ | |
13 | ||
14 | #include <linux/export.h> | |
15 | #include <linux/jiffies.h> | |
16 | #include <linux/regmap.h> | |
17 | #include <linux/soc/mediatek/infracfg.h> | |
18 | #include <asm/processor.h> | |
19 | ||
20 | #define INFRA_TOPAXI_PROTECTEN 0x0220 | |
21 | #define INFRA_TOPAXI_PROTECTSTA1 0x0228 | |
22 | ||
23 | /** | |
24 | * mtk_infracfg_set_bus_protection - enable bus protection | |
25 | * @regmap: The infracfg regmap | |
26 | * @mask: The mask containing the protection bits to be enabled. | |
27 | * | |
28 | * This function enables the bus protection bits for disabled power | |
29 | * domains so that the system does not hang when some unit accesses the | |
30 | * bus while in power down. | |
31 | */ | |
32 | int mtk_infracfg_set_bus_protection(struct regmap *infracfg, u32 mask) | |
33 | { | |
34 | unsigned long expired; | |
35 | u32 val; | |
36 | int ret; | |
37 | ||
38 | regmap_update_bits(infracfg, INFRA_TOPAXI_PROTECTEN, mask, mask); | |
39 | ||
40 | expired = jiffies + HZ; | |
41 | ||
42 | while (1) { | |
43 | ret = regmap_read(infracfg, INFRA_TOPAXI_PROTECTSTA1, &val); | |
44 | if (ret) | |
45 | return ret; | |
46 | ||
47 | if ((val & mask) == mask) | |
48 | break; | |
49 | ||
50 | cpu_relax(); | |
51 | if (time_after(jiffies, expired)) | |
52 | return -EIO; | |
53 | } | |
54 | ||
55 | return 0; | |
56 | } | |
57 | ||
58 | /** | |
59 | * mtk_infracfg_clear_bus_protection - disable bus protection | |
60 | * @regmap: The infracfg regmap | |
61 | * @mask: The mask containing the protection bits to be disabled. | |
62 | * | |
63 | * This function disables the bus protection bits previously enabled with | |
64 | * mtk_infracfg_set_bus_protection. | |
65 | */ | |
66 | int mtk_infracfg_clear_bus_protection(struct regmap *infracfg, u32 mask) | |
67 | { | |
68 | unsigned long expired; | |
69 | int ret; | |
70 | ||
71 | regmap_update_bits(infracfg, INFRA_TOPAXI_PROTECTEN, mask, 0); | |
72 | ||
73 | expired = jiffies + HZ; | |
74 | ||
75 | while (1) { | |
76 | u32 val; | |
77 | ||
78 | ret = regmap_read(infracfg, INFRA_TOPAXI_PROTECTSTA1, &val); | |
79 | if (ret) | |
80 | return ret; | |
81 | ||
82 | if (!(val & mask)) | |
83 | break; | |
84 | ||
85 | cpu_relax(); | |
86 | if (time_after(jiffies, expired)) | |
87 | return -EIO; | |
88 | } | |
89 | ||
90 | return 0; | |
91 | } |