aboutsummaryrefslogtreecommitdiff
path: root/drivers/clk/clk-mux.c
blob: e54e79714818f931b8b6a4456b57d4154f114530 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2011 Sascha Hauer, Pengutronix <s.hauer@pengutronix.de>
 * Copyright (C) 2011 Richard Zhao, Linaro <richard.zhao@linaro.org>
 * Copyright (C) 2011-2012 Mike Turquette, Linaro Ltd <mturquette@linaro.org>
 *
 * Simple multiplexer clock implementation
 */

#include <linux/clk-provider.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/err.h>

/*
 * DOC: basic adjustable multiplexer clock that cannot gate
 *
 * Traits of this clock:
 * prepare - clk_prepare only ensures that parents are prepared
 * enable - clk_enable only ensures that parents are enabled
 * rate - rate is only affected by parent switching.  No clk_set_rate support
 * parent - parent is adjustable through clk_set_parent
 */

static inline u32 clk_mux_readl(struct clk_mux *mux)
{
	if (mux->flags & CLK_MUX_BIG_ENDIAN)
		return ioread32be(mux->reg);

	return readl(mux->reg);
}

static inline void clk_mux_writel(struct clk_mux *mux, u32 val)
{
	if (mux->flags & CLK_MUX_BIG_ENDIAN)
		iowrite32be(val, mux->reg);
	else
		writel(val, mux->reg);
}

int clk_mux_val_to_index(struct clk_hw *hw, u32 *table, unsigned int flags,
			 unsigned int val)
{
	int num_parents = clk_hw_get_num_parents(hw);

	if (table) {
		int i;

		for (i = 0; i < num_parents; i++)
			if (table[i] == val)
				return i;
		return -EINVAL;
	}

	if (val && (flags & CLK_MUX_INDEX_BIT))
		val = ffs(val) - 1;

	if (val && (flags & CLK_MUX_INDEX_ONE))
		val--;

	if (val >= num_parents)
		return -EINVAL;

	return val;
}
EXPORT_SYMBOL_GPL(clk_mux_val_to_index);

unsigned int clk_mux_index_to_val(u32 *table, unsigned int flags, u8 index)
{
	unsigned int val = index;

	if (table) {
		val = table[index];
	} else {
		if (flags & CLK_MUX_INDEX_BIT)
			val = 1 << index;

		if (flags & CLK_MUX_INDEX_ONE)
			val++;
	}

	return val;
}
EXPORT_SYMBOL_GPL(clk_mux_index_to_val);

static u8 clk_mux_get_parent(struct clk_hw *hw)
{
	struct clk_mux *mux = to_clk_mux(hw);
	u32 val;

	val = clk_mux_readl(mux) >> mux->shift;
	val &= mux->mask;

	return clk_mux_val_to_index(hw, mux->table, mux->flags, val);
}

static int clk_mux_set_parent(struct clk_hw *hw, u8 index)
{
	struct clk_mux *mux = to_clk_mux(hw);
	u32 val = clk_mux_index_to_val(mux->table, mux->flags, index);
	unsigned long flags = 0;
	u32 reg;

	if (mux->lock)
		spin_lock_irqsave(mux->lock, flags);
	else
		__acquire(mux->lock);

	if (mux->flags & CLK_MUX_HIWORD_MASK) {
		reg = mux->mask << (mux->shift + 16);
	} else {
		reg = clk_mux_readl(mux);
		reg &= ~(mux->mask << mux->shift);
	}
	val = val << mux->shift;
	reg |= val;
	clk_mux_writel(mux, reg);

	if (mux->lock)
		spin_unlock_irqrestore(mux->lock, flags);
	else
		__release(mux->lock);

	return 0;
}

static int clk_mux_determine_rate(struct clk_hw *hw,
				  struct clk_rate_request *req)
{
	struct clk_mux *mux = to_clk_mux(hw);

	return clk_mux_determine_rate_flags(hw, req, mux->flags);
}

const struct clk_ops clk_mux_ops = {
	.get_parent = clk_mux_get_parent,
	.set_parent = clk_mux_set_parent,
	.determine_rate = clk_mux_determine_rate,
};
EXPORT_SYMBOL_GPL(clk_mux_ops);

const struct clk_ops clk_mux_ro_ops = {
	.get_parent = clk_mux_get_parent,
};
EXPORT_SYMBOL_GPL(clk_mux_ro_ops);

struct clk_hw *__clk_hw_register_mux(struct device *dev, struct device_node *np,
		const char *name, u8 num_parents,
		const char * const *parent_names,
		const struct clk_hw **parent_hws,
		const struct clk_parent_data *parent_data,
		unsigned long flags, void __iomem *reg, u8 shift, u32 mask,
		u8 clk_mux_flags, u32 *table, spinlock_t *lock)
{
	struct clk_mux *mux;
	struct clk_hw *hw;
	struct clk_init_data init = {};
	u8 width = 0;
	int ret = -EINVAL;

	if (clk_mux_flags & CLK_MUX_HIWORD_MASK) {
		width = fls(mask) - ffs(mask) + 1;
		if (width + shift > 16) {
			pr_err("mux value exceeds LOWORD field\n");
			return ERR_PTR(-EINVAL);
		}
	}

	/* allocate the mux */
	mux = kzalloc(sizeof(*mux), GFP_KERNEL);
	if (!mux)
		return ERR_PTR(-ENOMEM);

	init.name = name;
	if (clk_mux_flags & CLK_MUX_READ_ONLY)
		init.ops = &clk_mux_ro_ops;
	else
		init.ops = &clk_mux_ops;
	init.flags = flags;
	init.parent_names = parent_names;
	init.parent_data = parent_data;
	init.parent_hws = parent_hws;
	init.num_parents = num_parents;

	/* struct clk_mux assignments */
	mux->reg = reg;
	mux->shift = shift;
	mux->mask = mask;
	mux->flags = clk_mux_flags;
	mux->lock = lock;
	mux->table = table;
	mux->hw.init = &init;

	hw = &mux->hw;
	if (dev || !np)
		ret = clk_hw_register(dev, hw);
	else if (np)
		ret = of_clk_hw_register(np, hw);
	if (ret) {
		kfree(mux);
		hw = ERR_PTR(ret);
	}

	return hw;
}
EXPORT_SYMBOL_GPL(__clk_hw_register_mux);

struct clk *clk_register_mux_table(struct device *dev, const char *name,
		const char * const *parent_names, u8 num_parents,
		unsigned long flags, void __iomem *reg, u8 shift, u32 mask,
		u8 clk_mux_flags, u32 *table, spinlock_t *lock)
{
	struct clk_hw *hw;

	hw = clk_hw_register_mux_table(dev, name, parent_names,
				       num_parents, flags, reg, shift, mask,
				       clk_mux_flags, table, lock);
	if (IS_ERR(hw))
		return ERR_CAST(hw);
	return hw->clk;
}
EXPORT_SYMBOL_GPL(clk_register_mux_table);

void clk_unregister_mux(struct clk *clk)
{
	struct clk_mux *mux;
	struct clk_hw *hw;

	hw = __clk_get_hw(clk);
	if (!hw)
		return;

	mux = to_clk_mux(hw);

	clk_unregister(clk);
	kfree(mux);
}
EXPORT_SYMBOL_GPL(clk_unregister_mux);

void clk_hw_unregister_mux(struct clk_hw *hw)
{
	struct clk_mux *mux;

	mux = to_clk_mux(hw);

	clk_hw_unregister(hw);
	kfree(mux);
}
EXPORT_SYMBOL_GPL(clk_hw_unregister_mux);