2 * Copyright (c) 2014 ROCKCHIP, Inc.
3 * Author: Dai Kelin <dkl@rock-chips.com>
4 * Based on codes from Heiko Stuebner <heiko@sntech.de>.
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
17 #include <linux/slab.h>
20 #include <linux/reset-controller.h>
21 #include <linux/spinlock.h>
22 #include <linux/of_address.h>
23 #include <linux/platform_device.h>
24 #include <linux/module.h>
26 #include <dt-bindings/clock/rockchip.h>
29 struct rockchip_reset {
30 struct reset_controller_dev rcdev;
31 void __iomem *reg_base;
38 static int rockchip_reset_assert(struct reset_controller_dev *rcdev,
41 struct rockchip_reset *reset = container_of(rcdev,
42 struct rockchip_reset,
44 int bank = id / reset->num_per_reg;
45 int offset = id % reset->num_per_reg;
47 if (reset->flags & ROCKCHIP_RESET_HIWORD_MASK) {
48 writel(BIT(offset) | (BIT(offset) << 16),
49 reset->reg_base + (bank * 4));
54 spin_lock_irqsave(&reset->lock, flags);
56 reg = readl(reset->reg_base + (bank * 4));
57 writel(reg | BIT(offset), reset->reg_base + (bank * 4));
59 spin_unlock_irqrestore(&reset->lock, flags);
65 static int rockchip_reset_deassert(struct reset_controller_dev *rcdev,
68 struct rockchip_reset *reset = container_of(rcdev,
69 struct rockchip_reset,
71 int bank = id / reset->num_per_reg;
72 int offset = id % reset->num_per_reg;
74 if (reset->flags & ROCKCHIP_RESET_HIWORD_MASK) {
75 writel((BIT(offset) << 16), reset->reg_base + (bank * 4));
80 spin_lock_irqsave(&reset->lock, flags);
82 reg = readl(reset->reg_base + (bank * 4));
83 writel(reg & ~BIT(offset), reset->reg_base + (bank * 4));
85 spin_unlock_irqrestore(&reset->lock, flags);
91 static struct reset_control_ops rockchip_reset_ops = {
92 .assert = rockchip_reset_assert,
93 .deassert = rockchip_reset_deassert,
96 static int rockchip_register_reset(struct device_node *np,
97 unsigned int num_regs,
98 void __iomem *base, u8 flags)
100 struct rockchip_reset *reset;
103 reset = kzalloc(sizeof(*reset), GFP_KERNEL);
107 reset->flags = flags;
108 reset->reg_base = base;
109 reset->num_regs = num_regs;
110 reset->num_per_reg = (flags & ROCKCHIP_RESET_HIWORD_MASK) ? 16 : 32;
111 spin_lock_init(&reset->lock);
113 reset->rcdev.owner = THIS_MODULE;
114 reset->rcdev.nr_resets = num_regs * reset->num_per_reg;
115 reset->rcdev.ops = &rockchip_reset_ops;
116 reset->rcdev.of_node = np;
117 ret = reset_controller_register(&reset->rcdev);
119 pr_err("%s: could not register reset controller, %d\n",
128 static int __init rockchip_reset_probe(struct platform_device *pdev)
130 struct resource *res;
132 resource_size_t size;
136 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
137 base = devm_ioremap_resource(&pdev->dev, res);
139 pr_err("%s: ioremap err\n", __func__);
140 return PTR_ERR(base);
143 size = resource_size(res);
145 pr_err("%s: wrong size value\n", __func__);
149 of_property_read_u32(pdev->dev.of_node, "rockchip,reset-flag", &flag);
151 return rockchip_register_reset(pdev->dev.of_node, size/4, base, flag);
154 static const struct of_device_id rockchip_reset_dt_ids[] = {
155 { .compatible = "rockchip,reset", },
158 MODULE_DEVICE_TABLE(of, rockchip_reset_dt_ids);
160 static struct platform_driver rockchip_reset_driver = {
162 .name = "rockchip-reset",
163 .owner = THIS_MODULE,
164 .of_match_table = rockchip_reset_dt_ids,
168 static int __init rockchip_reset_module_init(void)
170 return platform_driver_probe(&rockchip_reset_driver,
171 rockchip_reset_probe);
174 subsys_initcall_sync(rockchip_reset_module_init);