1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2015 Pengutronix, Sascha Hauer <kernel@pengutronix.de>
4 */
5
6#include <linux/export.h>
7#include <linux/jiffies.h>
8#include <linux/regmap.h>
9#include <linux/mfd/syscon.h>
10#include <linux/soc/mediatek/infracfg.h>
11#include <asm/processor.h>
12
13#define MTK_POLL_DELAY_US 10
14#define MTK_POLL_TIMEOUT (jiffies_to_usecs(HZ))
15
16/**
17 * mtk_infracfg_set_bus_protection - enable bus protection
18 * @infracfg: The infracfg regmap
19 * @mask: The mask containing the protection bits to be enabled.
20 * @reg_update: The boolean flag determines to set the protection bits
21 * by regmap_update_bits with enable register(PROTECTEN) or
22 * by regmap_write with set register(PROTECTEN_SET).
23 *
24 * This function enables the bus protection bits for disabled power
25 * domains so that the system does not hang when some unit accesses the
26 * bus while in power down.
27 */
28int mtk_infracfg_set_bus_protection(struct regmap *infracfg, u32 mask,
29 bool reg_update)
30{
31 u32 val;
32 int ret;
33
34 if (reg_update)
35 regmap_update_bits(map: infracfg, INFRA_TOPAXI_PROTECTEN, mask,
36 val: mask);
37 else
38 regmap_write(map: infracfg, INFRA_TOPAXI_PROTECTEN_SET, val: mask);
39
40 ret = regmap_read_poll_timeout(infracfg, INFRA_TOPAXI_PROTECTSTA1,
41 val, (val & mask) == mask,
42 MTK_POLL_DELAY_US, MTK_POLL_TIMEOUT);
43
44 return ret;
45}
46
47/**
48 * mtk_infracfg_clear_bus_protection - disable bus protection
49 * @infracfg: The infracfg regmap
50 * @mask: The mask containing the protection bits to be disabled.
51 * @reg_update: The boolean flag determines to clear the protection bits
52 * by regmap_update_bits with enable register(PROTECTEN) or
53 * by regmap_write with clear register(PROTECTEN_CLR).
54 *
55 * This function disables the bus protection bits previously enabled with
56 * mtk_infracfg_set_bus_protection.
57 */
58
59int mtk_infracfg_clear_bus_protection(struct regmap *infracfg, u32 mask,
60 bool reg_update)
61{
62 int ret;
63 u32 val;
64
65 if (reg_update)
66 regmap_update_bits(map: infracfg, INFRA_TOPAXI_PROTECTEN, mask, val: 0);
67 else
68 regmap_write(map: infracfg, INFRA_TOPAXI_PROTECTEN_CLR, val: mask);
69
70 ret = regmap_read_poll_timeout(infracfg, INFRA_TOPAXI_PROTECTSTA1,
71 val, !(val & mask),
72 MTK_POLL_DELAY_US, MTK_POLL_TIMEOUT);
73
74 return ret;
75}
76
77static int __init mtk_infracfg_init(void)
78{
79 struct regmap *infracfg;
80
81 /*
82 * MT8192 has an experimental path to route GPU traffic to the DSU's
83 * Accelerator Coherency Port, which is inadvertently enabled by
84 * default. It turns out not to work, so disable it to prevent spurious
85 * GPU faults.
86 */
87 infracfg = syscon_regmap_lookup_by_compatible(s: "mediatek,mt8192-infracfg");
88 if (!IS_ERR(ptr: infracfg))
89 regmap_set_bits(map: infracfg, MT8192_INFRA_CTRL,
90 MT8192_INFRA_CTRL_DISABLE_MFG2ACP);
91 return 0;
92}
93postcore_initcall(mtk_infracfg_init);
94

source code of linux/drivers/soc/mediatek/mtk-infracfg.c