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gerrit-public.fairphone.software / kernel / msm-4.9 / 5c47daf6e76f657d961a96d89f6419fde8eda557 / . / drivers / clk / rockchip / softrst.c
blob: 552f7bb15bc5bf82a8678ecc084fe7c06e0cea81 [file] [log] [blame]
Heiko Stübner85fa0c72014-07-03 01:59:39 +0200[diff] [blame]1/*
2 * Copyright (c) 2014 MundoReader S.L.
3 * Author: Heiko Stuebner <heiko@sntech.de>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 */
15
16#include <linux/slab.h>
17#include <linux/io.h>
18#include <linux/reset-controller.h>
19#include <linux/spinlock.h>
20#include "clk.h"
21
22struct rockchip_softrst {
23 struct reset_controller_dev rcdev;
24 void __iomem *reg_base;
25 int num_regs;
26 int num_per_reg;
27 u8 flags;
28 spinlock_t lock;
29};
30
31static int rockchip_softrst_assert(struct reset_controller_dev *rcdev,
32 unsigned long id)
33{
34 struct rockchip_softrst *softrst = container_of(rcdev,
35 struct rockchip_softrst,
36 rcdev);
37 int bank = id / softrst->num_per_reg;
38 int offset = id % softrst->num_per_reg;
39
40 if (softrst->flags & ROCKCHIP_SOFTRST_HIWORD_MASK) {
41 writel(BIT(offset) | (BIT(offset) << 16),
42 softrst->reg_base + (bank * 4));
43 } else {
44 unsigned long flags;
45 u32 reg;
46
47 spin_lock_irqsave(&softrst->lock, flags);
48
49 reg = readl(softrst->reg_base + (bank * 4));
50 writel(reg | BIT(offset), softrst->reg_base + (bank * 4));
51
52 spin_unlock_irqrestore(&softrst->lock, flags);
53 }
54
55 return 0;
56}
57
58static int rockchip_softrst_deassert(struct reset_controller_dev *rcdev,
59 unsigned long id)
60{
61 struct rockchip_softrst *softrst = container_of(rcdev,
62 struct rockchip_softrst,
63 rcdev);
64 int bank = id / softrst->num_per_reg;
65 int offset = id % softrst->num_per_reg;
66
67 if (softrst->flags & ROCKCHIP_SOFTRST_HIWORD_MASK) {
68 writel((BIT(offset) << 16), softrst->reg_base + (bank * 4));
69 } else {
70 unsigned long flags;
71 u32 reg;
72
73 spin_lock_irqsave(&softrst->lock, flags);
74
75 reg = readl(softrst->reg_base + (bank * 4));
76 writel(reg & ~BIT(offset), softrst->reg_base + (bank * 4));
77
78 spin_unlock_irqrestore(&softrst->lock, flags);
79 }
80
81 return 0;
82}
83
84static struct reset_control_ops rockchip_softrst_ops = {
85 .assert = rockchip_softrst_assert,
86 .deassert = rockchip_softrst_deassert,
87};
88
89void __init rockchip_register_softrst(struct device_node *np,
90 unsigned int num_regs,
91 void __iomem *base, u8 flags)
92{
93 struct rockchip_softrst *softrst;
94 int ret;
95
96 softrst = kzalloc(sizeof(*softrst), GFP_KERNEL);
97 if (!softrst)
98 return;
99
100 spin_lock_init(&softrst->lock);
101
102 softrst->reg_base = base;
103 softrst->flags = flags;
104 softrst->num_regs = num_regs;
105 softrst->num_per_reg = (flags & ROCKCHIP_SOFTRST_HIWORD_MASK) ? 16
106 : 32;
107
108 softrst->rcdev.owner = THIS_MODULE;
109 softrst->rcdev.nr_resets = num_regs * softrst->num_per_reg;
110 softrst->rcdev.ops = &rockchip_softrst_ops;
111 softrst->rcdev.of_node = np;
112 ret = reset_controller_register(&softrst->rcdev);
113 if (ret) {
114 pr_err("%s: could not register reset controller, %d\n",
115 __func__, ret);
116 kfree(softrst);
117 }
118};