tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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#define INFRA_TOPAXI_PROTECTEN_SET 0x0260
23#define INFRA_TOPAXI_PROTECTEN_CLR 0x0264
24
25/**
26 * mtk_infracfg_set_bus_protection - enable bus protection
27 * @regmap: The infracfg regmap
28 * @mask: The mask containing the protection bits to be enabled.
29 * @reg_update: The boolean flag determines to set the protection bits
30 * by regmap_update_bits with enable register(PROTECTEN) or
31 * by regmap_write with set register(PROTECTEN_SET).
32 *
33 * This function enables the bus protection bits for disabled power
34 * domains so that the system does not hang when some unit accesses the
35 * bus while in power down.
36 */
37int mtk_infracfg_set_bus_protection(struct regmap *infracfg, u32 mask,
38 bool reg_update)
39{
40 unsigned long expired;
41 u32 val;
42 int ret;
43
44 if (reg_update)
45 regmap_update_bits(infracfg, INFRA_TOPAXI_PROTECTEN, mask,
46 mask);
47 else
48 regmap_write(infracfg, INFRA_TOPAXI_PROTECTEN_SET, mask);
49
50 expired = jiffies + HZ;
51
52 while (1) {
53 ret = regmap_read(infracfg, INFRA_TOPAXI_PROTECTSTA1, &val);
54 if (ret)
55 return ret;
56
57 if ((val & mask) == mask)
58 break;
59
60 cpu_relax();
61 if (time_after(jiffies, expired))
62 return -EIO;
63 }
64
65 return 0;
66}
67
68/**
69 * mtk_infracfg_clear_bus_protection - disable bus protection
70 * @regmap: The infracfg regmap
71 * @mask: The mask containing the protection bits to be disabled.
72 * @reg_update: The boolean flag determines to clear the protection bits
73 * by regmap_update_bits with enable register(PROTECTEN) or
74 * by regmap_write with clear register(PROTECTEN_CLR).
75 *
76 * This function disables the bus protection bits previously enabled with
77 * mtk_infracfg_set_bus_protection.
78 */
79
80int mtk_infracfg_clear_bus_protection(struct regmap *infracfg, u32 mask,
81 bool reg_update)
82{
83 unsigned long expired;
84 int ret;
85
86 if (reg_update)
87 regmap_update_bits(infracfg, INFRA_TOPAXI_PROTECTEN, mask, 0);
88 else
89 regmap_write(infracfg, INFRA_TOPAXI_PROTECTEN_CLR, mask);
90
91 expired = jiffies + HZ;
92
93 while (1) {
94 u32 val;
95
96 ret = regmap_read(infracfg, INFRA_TOPAXI_PROTECTSTA1, &val);
97 if (ret)
98 return ret;
99
100 if (!(val & mask))
101 break;
102
103 cpu_relax();
104 if (time_after(jiffies, expired))
105 return -EIO;
106 }
107
108 return 0;
109}