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1/*
2 * Copyright (C) 2011 Sascha Hauer, Pengutronix <s.hauer@pengutronix.de>
3 * Copyright (C) 2011 Richard Zhao, Linaro <richard.zhao@linaro.org>
4 * Copyright (C) 2011-2012 Mike Turquette, Linaro Ltd <mturquette@linaro.org>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 *
10 * Simple multiplexer clock implementation
11 */
12
13#include <linux/clk.h>
14#include <linux/clk-provider.h>
15#include <linux/module.h>
16#include <linux/slab.h>
17#include <linux/io.h>
18#include <linux/err.h>
19
20/*
21 * DOC: basic adjustable multiplexer clock that cannot gate
22 *
23 * Traits of this clock:
24 * prepare - clk_prepare only ensures that parents are prepared
25 * enable - clk_enable only ensures that parents are enabled
26 * rate - rate is only affected by parent switching. No clk_set_rate support
27 * parent - parent is adjustable through clk_set_parent
28 */
29
30#define to_clk_mux(_hw) container_of(_hw, struct clk_mux, hw)
31
32static u8 clk_mux_get_parent(struct clk_hw *hw)
33{
34 struct clk_mux *mux = to_clk_mux(hw);
35 u32 val;
36
37 /*
38 * FIXME need a mux-specific flag to determine if val is bitwise or numeric
39 * e.g. sys_clkin_ck's clksel field is 3 bits wide, but ranges from 0x1
40 * to 0x7 (index starts at one)
41 * OTOH, pmd_trace_clk_mux_ck uses a separate bit for each clock, so
42 * val = 0x4 really means "bit 2, index starts at bit 0"
43 */
44 val = readl(mux->reg) >> mux->shift;
45 val &= (1 << mux->width) - 1;
46
47 if (val && (mux->flags & CLK_MUX_INDEX_BIT))
48 val = ffs(val) - 1;
49
50 if (val && (mux->flags & CLK_MUX_INDEX_ONE))
51 val--;
52
53 if (val >= __clk_get_num_parents(hw->clk))
54 return -EINVAL;
55
56 return val;
57}
58
59static int clk_mux_set_parent(struct clk_hw *hw, u8 index)
60{
61 struct clk_mux *mux = to_clk_mux(hw);
62 u32 val;
63 unsigned long flags = 0;
64
65 if (mux->flags & CLK_MUX_INDEX_BIT)
66 index = (1 << ffs(index));
67
68 if (mux->flags & CLK_MUX_INDEX_ONE)
69 index++;
70
71 if (mux->lock)
72 spin_lock_irqsave(mux->lock, flags);
73
74 val = readl(mux->reg);
75 val &= ~(((1 << mux->width) - 1) << mux->shift);
76 val |= index << mux->shift;
77 writel(val, mux->reg);
78
79 if (mux->lock)
80 spin_unlock_irqrestore(mux->lock, flags);
81
82 return 0;
83}
84
85const struct clk_ops clk_mux_ops = {
86 .get_parent = clk_mux_get_parent,
87 .set_parent = clk_mux_set_parent,
88};
89EXPORT_SYMBOL_GPL(clk_mux_ops);
90
91struct clk *clk_register_mux(struct device *dev, const char *name,
92 const char **parent_names, u8 num_parents, unsigned long flags,
93 void __iomem *reg, u8 shift, u8 width,
94 u8 clk_mux_flags, spinlock_t *lock)
95{
96 struct clk_mux *mux;
97 struct clk *clk;
98 struct clk_init_data init;
99
100 /* allocate the mux */
101 mux = kzalloc(sizeof(struct clk_mux), GFP_KERNEL);
102 if (!mux) {
103 pr_err("%s: could not allocate mux clk\n", __func__);
104 return ERR_PTR(-ENOMEM);
105 }
106
107 init.name = name;
108 init.ops = &clk_mux_ops;
109 init.flags = flags;
110 init.parent_names = parent_names;
111 init.num_parents = num_parents;
112
113 /* struct clk_mux assignments */
114 mux->reg = reg;
115 mux->shift = shift;
116 mux->width = width;
117 mux->flags = clk_mux_flags;
118 mux->lock = lock;
119 mux->hw.init = &init;
120
121 clk = clk_register(dev, &mux->hw);
122
123 if (IS_ERR(clk))
124 kfree(mux);
125
126 return clk;
127}
1/*
2 * Copyright (C) 2011 Sascha Hauer, Pengutronix <s.hauer@pengutronix.de>
3 * Copyright (C) 2011 Richard Zhao, Linaro <richard.zhao@linaro.org>
4 * Copyright (C) 2011-2012 Mike Turquette, Linaro Ltd <mturquette@linaro.org>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 *
10 * Simple multiplexer clock implementation
11 */
12
13#include <linux/clk-provider.h>
14#include <linux/module.h>
15#include <linux/slab.h>
16#include <linux/io.h>
17#include <linux/err.h>
18
19/*
20 * DOC: basic adjustable multiplexer clock that cannot gate
21 *
22 * Traits of this clock:
23 * prepare - clk_prepare only ensures that parents are prepared
24 * enable - clk_enable only ensures that parents are enabled
25 * rate - rate is only affected by parent switching. No clk_set_rate support
26 * parent - parent is adjustable through clk_set_parent
27 */
28
29static u8 clk_mux_get_parent(struct clk_hw *hw)
30{
31 struct clk_mux *mux = to_clk_mux(hw);
32 int num_parents = clk_hw_get_num_parents(hw);
33 u32 val;
34
35 /*
36 * FIXME need a mux-specific flag to determine if val is bitwise or numeric
37 * e.g. sys_clkin_ck's clksel field is 3 bits wide, but ranges from 0x1
38 * to 0x7 (index starts at one)
39 * OTOH, pmd_trace_clk_mux_ck uses a separate bit for each clock, so
40 * val = 0x4 really means "bit 2, index starts at bit 0"
41 */
42 val = clk_readl(mux->reg) >> mux->shift;
43 val &= mux->mask;
44
45 if (mux->table) {
46 int i;
47
48 for (i = 0; i < num_parents; i++)
49 if (mux->table[i] == val)
50 return i;
51 return -EINVAL;
52 }
53
54 if (val && (mux->flags & CLK_MUX_INDEX_BIT))
55 val = ffs(val) - 1;
56
57 if (val && (mux->flags & CLK_MUX_INDEX_ONE))
58 val--;
59
60 if (val >= num_parents)
61 return -EINVAL;
62
63 return val;
64}
65
66static int clk_mux_set_parent(struct clk_hw *hw, u8 index)
67{
68 struct clk_mux *mux = to_clk_mux(hw);
69 u32 val;
70 unsigned long flags = 0;
71
72 if (mux->table) {
73 index = mux->table[index];
74 } else {
75 if (mux->flags & CLK_MUX_INDEX_BIT)
76 index = 1 << index;
77
78 if (mux->flags & CLK_MUX_INDEX_ONE)
79 index++;
80 }
81
82 if (mux->lock)
83 spin_lock_irqsave(mux->lock, flags);
84 else
85 __acquire(mux->lock);
86
87 if (mux->flags & CLK_MUX_HIWORD_MASK) {
88 val = mux->mask << (mux->shift + 16);
89 } else {
90 val = clk_readl(mux->reg);
91 val &= ~(mux->mask << mux->shift);
92 }
93 val |= index << mux->shift;
94 clk_writel(val, mux->reg);
95
96 if (mux->lock)
97 spin_unlock_irqrestore(mux->lock, flags);
98 else
99 __release(mux->lock);
100
101 return 0;
102}
103
104const struct clk_ops clk_mux_ops = {
105 .get_parent = clk_mux_get_parent,
106 .set_parent = clk_mux_set_parent,
107 .determine_rate = __clk_mux_determine_rate,
108};
109EXPORT_SYMBOL_GPL(clk_mux_ops);
110
111const struct clk_ops clk_mux_ro_ops = {
112 .get_parent = clk_mux_get_parent,
113};
114EXPORT_SYMBOL_GPL(clk_mux_ro_ops);
115
116struct clk *clk_register_mux_table(struct device *dev, const char *name,
117 const char * const *parent_names, u8 num_parents,
118 unsigned long flags,
119 void __iomem *reg, u8 shift, u32 mask,
120 u8 clk_mux_flags, u32 *table, spinlock_t *lock)
121{
122 struct clk_mux *mux;
123 struct clk *clk;
124 struct clk_init_data init;
125 u8 width = 0;
126
127 if (clk_mux_flags & CLK_MUX_HIWORD_MASK) {
128 width = fls(mask) - ffs(mask) + 1;
129 if (width + shift > 16) {
130 pr_err("mux value exceeds LOWORD field\n");
131 return ERR_PTR(-EINVAL);
132 }
133 }
134
135 /* allocate the mux */
136 mux = kzalloc(sizeof(struct clk_mux), GFP_KERNEL);
137 if (!mux) {
138 pr_err("%s: could not allocate mux clk\n", __func__);
139 return ERR_PTR(-ENOMEM);
140 }
141
142 init.name = name;
143 if (clk_mux_flags & CLK_MUX_READ_ONLY)
144 init.ops = &clk_mux_ro_ops;
145 else
146 init.ops = &clk_mux_ops;
147 init.flags = flags | CLK_IS_BASIC;
148 init.parent_names = parent_names;
149 init.num_parents = num_parents;
150
151 /* struct clk_mux assignments */
152 mux->reg = reg;
153 mux->shift = shift;
154 mux->mask = mask;
155 mux->flags = clk_mux_flags;
156 mux->lock = lock;
157 mux->table = table;
158 mux->hw.init = &init;
159
160 clk = clk_register(dev, &mux->hw);
161
162 if (IS_ERR(clk))
163 kfree(mux);
164
165 return clk;
166}
167EXPORT_SYMBOL_GPL(clk_register_mux_table);
168
169struct clk *clk_register_mux(struct device *dev, const char *name,
170 const char * const *parent_names, u8 num_parents,
171 unsigned long flags,
172 void __iomem *reg, u8 shift, u8 width,
173 u8 clk_mux_flags, spinlock_t *lock)
174{
175 u32 mask = BIT(width) - 1;
176
177 return clk_register_mux_table(dev, name, parent_names, num_parents,
178 flags, reg, shift, mask, clk_mux_flags,
179 NULL, lock);
180}
181EXPORT_SYMBOL_GPL(clk_register_mux);
182
183void clk_unregister_mux(struct clk *clk)
184{
185 struct clk_mux *mux;
186 struct clk_hw *hw;
187
188 hw = __clk_get_hw(clk);
189 if (!hw)
190 return;
191
192 mux = to_clk_mux(hw);
193
194 clk_unregister(clk);
195 kfree(mux);
196}
197EXPORT_SYMBOL_GPL(clk_unregister_mux);