clk-cpumux.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Copyright (c) 2015 Linaro Ltd.
  4 * Author: Pi-Cheng Chen <pi-cheng.chen@linaro.org>
  5 */
  6
  7#include <linux/clk-provider.h>
  8#include <linux/container_of.h>
  9#include <linux/err.h>
 10#include <linux/mfd/syscon.h>
 11#include <linux/module.h>
 12#include <linux/regmap.h>
 13#include <linux/slab.h>
 14
 15#include "clk-mtk.h"
 16#include "clk-cpumux.h"
 17
 18struct mtk_clk_cpumux {
 19	struct clk_hw	hw;
 20	struct regmap	*regmap;
 21	u32		reg;
 22	u32		mask;
 23	u8		shift;
 24};
 25
 26static inline struct mtk_clk_cpumux *to_mtk_clk_cpumux(struct clk_hw *_hw)
 27{
 28	return container_of(_hw, struct mtk_clk_cpumux, hw);
 29}
 30
 31static u8 clk_cpumux_get_parent(struct clk_hw *hw)
 32{
 33	struct mtk_clk_cpumux *mux = to_mtk_clk_cpumux(hw);
 34	unsigned int val;
 35
 36	regmap_read(mux->regmap, mux->reg, &val);
 37
 38	val >>= mux->shift;
 39	val &= mux->mask;
 40
 41	return val;
 42}
 43
 44static int clk_cpumux_set_parent(struct clk_hw *hw, u8 index)
 45{
 46	struct mtk_clk_cpumux *mux = to_mtk_clk_cpumux(hw);
 47	u32 mask, val;
 48
 49	val = index << mux->shift;
 50	mask = mux->mask << mux->shift;
 51
 52	return regmap_update_bits(mux->regmap, mux->reg, mask, val);
 53}
 54
 55static const struct clk_ops clk_cpumux_ops = {
 56	.determine_rate = clk_hw_determine_rate_no_reparent,
 57	.get_parent = clk_cpumux_get_parent,
 58	.set_parent = clk_cpumux_set_parent,
 59};
 60
 61static struct clk_hw *
 62mtk_clk_register_cpumux(struct device *dev, const struct mtk_composite *mux,
 63			struct regmap *regmap)
 64{
 65	struct mtk_clk_cpumux *cpumux;
 66	int ret;
 67	struct clk_init_data init;
 68
 69	cpumux = kzalloc(sizeof(*cpumux), GFP_KERNEL);
 70	if (!cpumux)
 71		return ERR_PTR(-ENOMEM);
 72
 73	init.name = mux->name;
 74	init.ops = &clk_cpumux_ops;
 75	init.parent_names = mux->parent_names;
 76	init.num_parents = mux->num_parents;
 77	init.flags = mux->flags;
 78
 79	cpumux->reg = mux->mux_reg;
 80	cpumux->shift = mux->mux_shift;
 81	cpumux->mask = BIT(mux->mux_width) - 1;
 82	cpumux->regmap = regmap;
 83	cpumux->hw.init = &init;
 84
 85	ret = clk_hw_register(dev, &cpumux->hw);
 86	if (ret) {
 87		kfree(cpumux);
 88		return ERR_PTR(ret);
 89	}
 90
 91	return &cpumux->hw;
 92}
 93
 94static void mtk_clk_unregister_cpumux(struct clk_hw *hw)
 95{
 96	struct mtk_clk_cpumux *cpumux;
 97	if (!hw)
 98		return;
 99
100	cpumux = to_mtk_clk_cpumux(hw);
101
102	clk_hw_unregister(hw);
103	kfree(cpumux);
104}
105
106int mtk_clk_register_cpumuxes(struct device *dev, struct device_node *node,
107			      const struct mtk_composite *clks, int num,
108			      struct clk_hw_onecell_data *clk_data)
109{
110	int i;
111	struct clk_hw *hw;
112	struct regmap *regmap;
113
114	regmap = device_node_to_regmap(node);
115	if (IS_ERR(regmap)) {
116		pr_err("Cannot find regmap for %pOF: %pe\n", node, regmap);
117		return PTR_ERR(regmap);
118	}
119
120	for (i = 0; i < num; i++) {
121		const struct mtk_composite *mux = &clks[i];
122
123		if (!IS_ERR_OR_NULL(clk_data->hws[mux->id])) {
124			pr_warn("%pOF: Trying to register duplicate clock ID: %d\n",
125				node, mux->id);
126			continue;
127		}
128
129		hw = mtk_clk_register_cpumux(dev, mux, regmap);
130		if (IS_ERR(hw)) {
131			pr_err("Failed to register clk %s: %pe\n", mux->name,
132			       hw);
133			goto err;
134		}
135
136		clk_data->hws[mux->id] = hw;
137	}
138
139	return 0;
140
141err:
142	while (--i >= 0) {
143		const struct mtk_composite *mux = &clks[i];
144
145		if (IS_ERR_OR_NULL(clk_data->hws[mux->id]))
146			continue;
147
148		mtk_clk_unregister_cpumux(clk_data->hws[mux->id]);
149		clk_data->hws[mux->id] = ERR_PTR(-ENOENT);
150	}
151
152	return PTR_ERR(hw);
153}
154EXPORT_SYMBOL_GPL(mtk_clk_register_cpumuxes);
155
156void mtk_clk_unregister_cpumuxes(const struct mtk_composite *clks, int num,
157				 struct clk_hw_onecell_data *clk_data)
158{
159	int i;
160
161	for (i = num; i > 0; i--) {
162		const struct mtk_composite *mux = &clks[i - 1];
163
164		if (IS_ERR_OR_NULL(clk_data->hws[mux->id]))
165			continue;
166
167		mtk_clk_unregister_cpumux(clk_data->hws[mux->id]);
168		clk_data->hws[mux->id] = ERR_PTR(-ENOENT);
169	}
170}
171EXPORT_SYMBOL_GPL(mtk_clk_unregister_cpumuxes);
172
173MODULE_LICENSE("GPL");