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>
19 #include <linux/reset-controller.h>
20 #include <linux/spinlock.h>
21 #include <linux/of_address.h>
22 #include <linux/platform_device.h>
23 #include <linux/module.h>
25 #include <dt-bindings/clock/rockchip.h>
28 struct rockchip_reset {
29 struct reset_controller_dev rcdev;
30 void __iomem *reg_base;
37 static int rockchip_reset_assert(struct reset_controller_dev *rcdev,
40 struct rockchip_reset *reset = container_of(rcdev,
41 struct rockchip_reset,
43 int bank = id / reset->num_per_reg;
44 int offset = id % reset->num_per_reg;
46 if (reset->flags & ROCKCHIP_RESET_HIWORD_MASK) {
47 writel(BIT(offset) | (BIT(offset) << 16),
48 reset->reg_base + (bank * 4));
53 spin_lock_irqsave(&reset->lock, flags);
55 reg = readl(reset->reg_base + (bank * 4));
56 writel(reg | BIT(offset), reset->reg_base + (bank * 4));
58 spin_unlock_irqrestore(&reset->lock, flags);
64 static int rockchip_reset_deassert(struct reset_controller_dev *rcdev,
67 struct rockchip_reset *reset = container_of(rcdev,
68 struct rockchip_reset,
70 int bank = id / reset->num_per_reg;
71 int offset = id % reset->num_per_reg;
73 if (reset->flags & ROCKCHIP_RESET_HIWORD_MASK) {
74 writel((BIT(offset) << 16), reset->reg_base + (bank * 4));
79 spin_lock_irqsave(&reset->lock, flags);
81 reg = readl(reset->reg_base + (bank * 4));
82 writel(reg & ~BIT(offset), reset->reg_base + (bank * 4));
84 spin_unlock_irqrestore(&reset->lock, flags);
90 static struct reset_control_ops rockchip_reset_ops = {
91 .assert = rockchip_reset_assert,
92 .deassert = rockchip_reset_deassert,
95 static int rockchip_register_reset(struct device_node *np,
96 unsigned int num_regs,
97 void __iomem *base, u8 flags)
99 struct rockchip_reset *reset;
102 reset = kzalloc(sizeof(*reset), GFP_KERNEL);
106 reset->flags = flags;
107 reset->reg_base = base;
108 reset->num_regs = num_regs;
109 reset->num_per_reg = (flags & ROCKCHIP_RESET_HIWORD_MASK) ? 16 : 32;
110 spin_lock_init(&reset->lock);
112 reset->rcdev.owner = THIS_MODULE;
113 reset->rcdev.nr_resets = num_regs * reset->num_per_reg;
114 reset->rcdev.ops = &rockchip_reset_ops;
115 reset->rcdev.of_node = np;
116 ret = reset_controller_register(&reset->rcdev);
118 pr_err("%s: could not register reset controller, %d\n",
127 static int rockchip_reset_probe(struct platform_device *pdev)
129 struct resource *res;
131 resource_size_t size;
135 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
136 base = devm_ioremap_resource(&pdev->dev, res);
138 pr_err("%s: ioremap err\n", __func__);
139 return PTR_ERR(base);
142 size = resource_size(res);
144 pr_err("%s: wrong size value\n", __func__);
148 of_property_read_u32(pdev->dev.of_node, "rockchip,reset-flag", &flag);
150 return rockchip_register_reset(pdev->dev.of_node, size/4, base, flag);
153 static const struct of_device_id rockchip_reset_dt_ids[] = {
154 { .compatible = "rockchip,reset", },
157 MODULE_DEVICE_TABLE(of, rockchip_reset_dt_ids);
159 static struct platform_driver rockchip_reset_driver = {
160 .probe = rockchip_reset_probe,
162 .name = "rockchip-reset",
163 .owner = THIS_MODULE,
164 .of_match_table = rockchip_reset_dt_ids,
167 module_platform_driver(rockchip_reset_driver);