softrst.c

  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * Copyright (c) 2014 MundoReader S.L.
  4 * Author: Heiko Stuebner <heiko@sntech.de>
  5 */
  6
  7#include <linux/slab.h>
  8#include <linux/io.h>
  9#include <linux/reset-controller.h>
 10#include <linux/spinlock.h>
 11#include "clk.h"
 12
 13struct rockchip_softrst {
 14	struct reset_controller_dev	rcdev;
 15	const int			*lut;
 16	void __iomem			*reg_base;
 17	int				num_regs;
 18	int				num_per_reg;
 19	u8				flags;
 20	spinlock_t			lock;
 21};
 22
 23static int rockchip_softrst_assert(struct reset_controller_dev *rcdev,
 24			      unsigned long id)
 25{
 26	struct rockchip_softrst *softrst = container_of(rcdev,
 27						     struct rockchip_softrst,
 28						     rcdev);
 29	int bank, offset;
 30
 31	if (softrst->lut)
 32		id = softrst->lut[id];
 33
 34	bank = id / softrst->num_per_reg;
 35	offset = id % softrst->num_per_reg;
 36
 37	if (softrst->flags & ROCKCHIP_SOFTRST_HIWORD_MASK) {
 38		writel(BIT(offset) | (BIT(offset) << 16),
 39		       softrst->reg_base + (bank * 4));
 40	} else {
 41		unsigned long flags;
 42		u32 reg;
 43
 44		spin_lock_irqsave(&softrst->lock, flags);
 45
 46		reg = readl(softrst->reg_base + (bank * 4));
 47		writel(reg | BIT(offset), softrst->reg_base + (bank * 4));
 48
 49		spin_unlock_irqrestore(&softrst->lock, flags);
 50	}
 51
 52	return 0;
 53}
 54
 55static int rockchip_softrst_deassert(struct reset_controller_dev *rcdev,
 56				unsigned long id)
 57{
 58	struct rockchip_softrst *softrst = container_of(rcdev,
 59						     struct rockchip_softrst,
 60						     rcdev);
 61	int bank, offset;
 62
 63	if (softrst->lut)
 64		id = softrst->lut[id];
 65
 66	bank = id / softrst->num_per_reg;
 67	offset = id % softrst->num_per_reg;
 68
 69	if (softrst->flags & ROCKCHIP_SOFTRST_HIWORD_MASK) {
 70		writel((BIT(offset) << 16), softrst->reg_base + (bank * 4));
 71	} else {
 72		unsigned long flags;
 73		u32 reg;
 74
 75		spin_lock_irqsave(&softrst->lock, flags);
 76
 77		reg = readl(softrst->reg_base + (bank * 4));
 78		writel(reg & ~BIT(offset), softrst->reg_base + (bank * 4));
 79
 80		spin_unlock_irqrestore(&softrst->lock, flags);
 81	}
 82
 83	return 0;
 84}
 85
 86static const struct reset_control_ops rockchip_softrst_ops = {
 87	.assert		= rockchip_softrst_assert,
 88	.deassert	= rockchip_softrst_deassert,
 89};
 90
 91void rockchip_register_softrst_lut(struct device_node *np,
 92				   const int *lookup_table,
 93				   unsigned int num_regs,
 94				   void __iomem *base, u8 flags)
 95{
 96	struct rockchip_softrst *softrst;
 97	int ret;
 98
 99	softrst = kzalloc(sizeof(*softrst), GFP_KERNEL);
100	if (!softrst)
101		return;
102
103	spin_lock_init(&softrst->lock);
104
105	softrst->reg_base = base;
106	softrst->lut = lookup_table;
107	softrst->flags = flags;
108	softrst->num_regs = num_regs;
109	softrst->num_per_reg = (flags & ROCKCHIP_SOFTRST_HIWORD_MASK) ? 16
110								      : 32;
111
112	softrst->rcdev.owner = THIS_MODULE;
113	if (lookup_table)
114		softrst->rcdev.nr_resets = num_regs;
115	else
116		softrst->rcdev.nr_resets = num_regs * softrst->num_per_reg;
117	softrst->rcdev.ops = &rockchip_softrst_ops;
118	softrst->rcdev.of_node = np;
119	ret = reset_controller_register(&softrst->rcdev);
120	if (ret) {
121		pr_err("%s: could not register reset controller, %d\n",
122		       __func__, ret);
123		kfree(softrst);
124	}
125};
126EXPORT_SYMBOL_GPL(rockchip_register_softrst_lut);