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9d9f78ed MT |
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 | ||
9d9f78ed MT |
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 | ||
29 | #define to_clk_mux(_hw) container_of(_hw, struct clk_mux, hw) | |
30 | ||
31 | static u8 clk_mux_get_parent(struct clk_hw *hw) | |
32 | { | |
33 | struct clk_mux *mux = to_clk_mux(hw); | |
ce4f3313 | 34 | int num_parents = __clk_get_num_parents(hw->clk); |
9d9f78ed MT |
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 | */ | |
aa514ce3 | 44 | val = clk_readl(mux->reg) >> mux->shift; |
ce4f3313 PDS |
45 | val &= mux->mask; |
46 | ||
47 | if (mux->table) { | |
48 | int i; | |
49 | ||
50 | for (i = 0; i < num_parents; i++) | |
51 | if (mux->table[i] == val) | |
52 | return i; | |
53 | return -EINVAL; | |
54 | } | |
9d9f78ed MT |
55 | |
56 | if (val && (mux->flags & CLK_MUX_INDEX_BIT)) | |
57 | val = ffs(val) - 1; | |
58 | ||
59 | if (val && (mux->flags & CLK_MUX_INDEX_ONE)) | |
60 | val--; | |
61 | ||
ce4f3313 | 62 | if (val >= num_parents) |
9d9f78ed MT |
63 | return -EINVAL; |
64 | ||
65 | return val; | |
66 | } | |
9d9f78ed MT |
67 | |
68 | static int clk_mux_set_parent(struct clk_hw *hw, u8 index) | |
69 | { | |
70 | struct clk_mux *mux = to_clk_mux(hw); | |
71 | u32 val; | |
72 | unsigned long flags = 0; | |
73 | ||
ce4f3313 PDS |
74 | if (mux->table) |
75 | index = mux->table[index]; | |
9d9f78ed | 76 | |
ce4f3313 PDS |
77 | else { |
78 | if (mux->flags & CLK_MUX_INDEX_BIT) | |
6793b3cd | 79 | index = 1 << index; |
ce4f3313 PDS |
80 | |
81 | if (mux->flags & CLK_MUX_INDEX_ONE) | |
82 | index++; | |
83 | } | |
9d9f78ed MT |
84 | |
85 | if (mux->lock) | |
86 | spin_lock_irqsave(mux->lock, flags); | |
661e2180 SB |
87 | else |
88 | __acquire(mux->lock); | |
9d9f78ed | 89 | |
ba492e90 HZ |
90 | if (mux->flags & CLK_MUX_HIWORD_MASK) { |
91 | val = mux->mask << (mux->shift + 16); | |
92 | } else { | |
aa514ce3 | 93 | val = clk_readl(mux->reg); |
ba492e90 HZ |
94 | val &= ~(mux->mask << mux->shift); |
95 | } | |
9d9f78ed | 96 | val |= index << mux->shift; |
aa514ce3 | 97 | clk_writel(val, mux->reg); |
9d9f78ed MT |
98 | |
99 | if (mux->lock) | |
100 | spin_unlock_irqrestore(mux->lock, flags); | |
661e2180 SB |
101 | else |
102 | __release(mux->lock); | |
9d9f78ed MT |
103 | |
104 | return 0; | |
105 | } | |
9d9f78ed | 106 | |
822c250e | 107 | const struct clk_ops clk_mux_ops = { |
9d9f78ed MT |
108 | .get_parent = clk_mux_get_parent, |
109 | .set_parent = clk_mux_set_parent, | |
e366fdd7 | 110 | .determine_rate = __clk_mux_determine_rate, |
9d9f78ed MT |
111 | }; |
112 | EXPORT_SYMBOL_GPL(clk_mux_ops); | |
113 | ||
c57acd14 TF |
114 | const struct clk_ops clk_mux_ro_ops = { |
115 | .get_parent = clk_mux_get_parent, | |
116 | }; | |
117 | EXPORT_SYMBOL_GPL(clk_mux_ro_ops); | |
118 | ||
ce4f3313 | 119 | struct clk *clk_register_mux_table(struct device *dev, const char *name, |
2893c379 SH |
120 | const char * const *parent_names, u8 num_parents, |
121 | unsigned long flags, | |
ce4f3313 PDS |
122 | void __iomem *reg, u8 shift, u32 mask, |
123 | u8 clk_mux_flags, u32 *table, spinlock_t *lock) | |
9d9f78ed MT |
124 | { |
125 | struct clk_mux *mux; | |
27d54591 | 126 | struct clk *clk; |
0197b3ea | 127 | struct clk_init_data init; |
ba492e90 HZ |
128 | u8 width = 0; |
129 | ||
130 | if (clk_mux_flags & CLK_MUX_HIWORD_MASK) { | |
131 | width = fls(mask) - ffs(mask) + 1; | |
132 | if (width + shift > 16) { | |
133 | pr_err("mux value exceeds LOWORD field\n"); | |
134 | return ERR_PTR(-EINVAL); | |
135 | } | |
136 | } | |
9d9f78ed | 137 | |
27d54591 | 138 | /* allocate the mux */ |
10363b58 | 139 | mux = kzalloc(sizeof(struct clk_mux), GFP_KERNEL); |
9d9f78ed MT |
140 | if (!mux) { |
141 | pr_err("%s: could not allocate mux clk\n", __func__); | |
142 | return ERR_PTR(-ENOMEM); | |
143 | } | |
144 | ||
0197b3ea | 145 | init.name = name; |
c57acd14 TF |
146 | if (clk_mux_flags & CLK_MUX_READ_ONLY) |
147 | init.ops = &clk_mux_ro_ops; | |
148 | else | |
149 | init.ops = &clk_mux_ops; | |
f7d8caad | 150 | init.flags = flags | CLK_IS_BASIC; |
0197b3ea SK |
151 | init.parent_names = parent_names; |
152 | init.num_parents = num_parents; | |
153 | ||
9d9f78ed MT |
154 | /* struct clk_mux assignments */ |
155 | mux->reg = reg; | |
156 | mux->shift = shift; | |
ce4f3313 | 157 | mux->mask = mask; |
9d9f78ed MT |
158 | mux->flags = clk_mux_flags; |
159 | mux->lock = lock; | |
ce4f3313 | 160 | mux->table = table; |
31df9db9 | 161 | mux->hw.init = &init; |
9d9f78ed | 162 | |
0197b3ea | 163 | clk = clk_register(dev, &mux->hw); |
27d54591 MT |
164 | |
165 | if (IS_ERR(clk)) | |
166 | kfree(mux); | |
167 | ||
168 | return clk; | |
9d9f78ed | 169 | } |
5cfe10bb | 170 | EXPORT_SYMBOL_GPL(clk_register_mux_table); |
ce4f3313 PDS |
171 | |
172 | struct clk *clk_register_mux(struct device *dev, const char *name, | |
2893c379 SH |
173 | const char * const *parent_names, u8 num_parents, |
174 | unsigned long flags, | |
ce4f3313 PDS |
175 | void __iomem *reg, u8 shift, u8 width, |
176 | u8 clk_mux_flags, spinlock_t *lock) | |
177 | { | |
178 | u32 mask = BIT(width) - 1; | |
179 | ||
180 | return clk_register_mux_table(dev, name, parent_names, num_parents, | |
181 | flags, reg, shift, mask, clk_mux_flags, | |
182 | NULL, lock); | |
183 | } | |
5cfe10bb | 184 | EXPORT_SYMBOL_GPL(clk_register_mux); |
4e3c021f KK |
185 | |
186 | void clk_unregister_mux(struct clk *clk) | |
187 | { | |
188 | struct clk_mux *mux; | |
189 | struct clk_hw *hw; | |
190 | ||
191 | hw = __clk_get_hw(clk); | |
192 | if (!hw) | |
193 | return; | |
194 | ||
195 | mux = to_clk_mux(hw); | |
196 | ||
197 | clk_unregister(clk); | |
198 | kfree(mux); | |
199 | } | |
200 | EXPORT_SYMBOL_GPL(clk_unregister_mux); |