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91b87a47 LW |
1 | /* |
2 | * Driver for the ICST307 VCO clock found in the ARM Reference designs. | |
3 | * We wrap the custom interface from <asm/hardware/icst.h> into the generic | |
4 | * clock framework. | |
5 | * | |
401301cc LW |
6 | * Copyright (C) 2012 Linus Walleij |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify | |
9 | * it under the terms of the GNU General Public License version 2 as | |
10 | * published by the Free Software Foundation. | |
11 | * | |
91b87a47 LW |
12 | * TODO: when all ARM reference designs are migrated to generic clocks, the |
13 | * ICST clock code from the ARM tree should probably be merged into this | |
14 | * file. | |
15 | */ | |
6d31e3b2 SB |
16 | #include <linux/kernel.h> |
17 | #include <linux/slab.h> | |
18 | #include <linux/export.h> | |
91b87a47 LW |
19 | #include <linux/err.h> |
20 | #include <linux/clk-provider.h> | |
7a9ad671 | 21 | #include <linux/io.h> |
91b87a47 LW |
22 | |
23 | #include "clk-icst.h" | |
24 | ||
25 | /** | |
26 | * struct clk_icst - ICST VCO clock wrapper | |
27 | * @hw: corresponding clock hardware entry | |
7a9ad671 LW |
28 | * @vcoreg: VCO register address |
29 | * @lockreg: VCO lock register address | |
91b87a47 LW |
30 | * @params: parameters for this ICST instance |
31 | * @rate: current rate | |
91b87a47 LW |
32 | */ |
33 | struct clk_icst { | |
34 | struct clk_hw hw; | |
7a9ad671 LW |
35 | void __iomem *vcoreg; |
36 | void __iomem *lockreg; | |
a183da63 | 37 | struct icst_params *params; |
91b87a47 | 38 | unsigned long rate; |
91b87a47 LW |
39 | }; |
40 | ||
41 | #define to_icst(_hw) container_of(_hw, struct clk_icst, hw) | |
42 | ||
7a9ad671 LW |
43 | /** |
44 | * vco_get() - get ICST VCO settings from a certain register | |
45 | * @vcoreg: register containing the VCO settings | |
46 | */ | |
47 | static struct icst_vco vco_get(void __iomem *vcoreg) | |
48 | { | |
49 | u32 val; | |
50 | struct icst_vco vco; | |
51 | ||
52 | val = readl(vcoreg); | |
53 | vco.v = val & 0x1ff; | |
54 | vco.r = (val >> 9) & 0x7f; | |
55 | vco.s = (val >> 16) & 03; | |
56 | return vco; | |
57 | } | |
58 | ||
59 | /** | |
60 | * vco_set() - commit changes to an ICST VCO | |
61 | * @locreg: register to poke to unlock the VCO for writing | |
62 | * @vcoreg: register containing the VCO settings | |
63 | * @vco: ICST VCO parameters to commit | |
64 | */ | |
65 | static void vco_set(void __iomem *lockreg, | |
66 | void __iomem *vcoreg, | |
67 | struct icst_vco vco) | |
68 | { | |
69 | u32 val; | |
70 | ||
71 | val = readl(vcoreg) & ~0x7ffff; | |
72 | val |= vco.v | (vco.r << 9) | (vco.s << 16); | |
73 | ||
74 | /* This magic unlocks the VCO so it can be controlled */ | |
75 | writel(0xa05f, lockreg); | |
76 | writel(val, vcoreg); | |
77 | /* This locks the VCO again */ | |
78 | writel(0, lockreg); | |
79 | } | |
80 | ||
81 | ||
91b87a47 LW |
82 | static unsigned long icst_recalc_rate(struct clk_hw *hw, |
83 | unsigned long parent_rate) | |
84 | { | |
85 | struct clk_icst *icst = to_icst(hw); | |
86 | struct icst_vco vco; | |
87 | ||
a183da63 LW |
88 | if (parent_rate) |
89 | icst->params->ref = parent_rate; | |
7a9ad671 | 90 | vco = vco_get(icst->vcoreg); |
91b87a47 LW |
91 | icst->rate = icst_hz(icst->params, vco); |
92 | return icst->rate; | |
93 | } | |
94 | ||
95 | static long icst_round_rate(struct clk_hw *hw, unsigned long rate, | |
96 | unsigned long *prate) | |
97 | { | |
98 | struct clk_icst *icst = to_icst(hw); | |
99 | struct icst_vco vco; | |
100 | ||
101 | vco = icst_hz_to_vco(icst->params, rate); | |
102 | return icst_hz(icst->params, vco); | |
103 | } | |
104 | ||
105 | static int icst_set_rate(struct clk_hw *hw, unsigned long rate, | |
106 | unsigned long parent_rate) | |
107 | { | |
108 | struct clk_icst *icst = to_icst(hw); | |
109 | struct icst_vco vco; | |
110 | ||
a183da63 LW |
111 | if (parent_rate) |
112 | icst->params->ref = parent_rate; | |
91b87a47 LW |
113 | vco = icst_hz_to_vco(icst->params, rate); |
114 | icst->rate = icst_hz(icst->params, vco); | |
2f9f64bc | 115 | vco_set(icst->lockreg, icst->vcoreg, vco); |
91b87a47 LW |
116 | return 0; |
117 | } | |
118 | ||
119 | static const struct clk_ops icst_ops = { | |
120 | .recalc_rate = icst_recalc_rate, | |
121 | .round_rate = icst_round_rate, | |
122 | .set_rate = icst_set_rate, | |
123 | }; | |
124 | ||
7a9ad671 LW |
125 | struct clk *icst_clk_register(struct device *dev, |
126 | const struct clk_icst_desc *desc, | |
ae6e694e | 127 | const char *name, |
bf6edb4b | 128 | const char *parent_name, |
7a9ad671 | 129 | void __iomem *base) |
91b87a47 LW |
130 | { |
131 | struct clk *clk; | |
132 | struct clk_icst *icst; | |
133 | struct clk_init_data init; | |
a183da63 | 134 | struct icst_params *pclone; |
91b87a47 LW |
135 | |
136 | icst = kzalloc(sizeof(struct clk_icst), GFP_KERNEL); | |
137 | if (!icst) { | |
138 | pr_err("could not allocate ICST clock!\n"); | |
139 | return ERR_PTR(-ENOMEM); | |
140 | } | |
a183da63 LW |
141 | |
142 | pclone = kmemdup(desc->params, sizeof(*pclone), GFP_KERNEL); | |
143 | if (!pclone) { | |
ab7ad353 | 144 | kfree(icst); |
a183da63 LW |
145 | pr_err("could not clone ICST params\n"); |
146 | return ERR_PTR(-ENOMEM); | |
147 | } | |
148 | ||
ae6e694e | 149 | init.name = name; |
91b87a47 LW |
150 | init.ops = &icst_ops; |
151 | init.flags = CLK_IS_ROOT; | |
a183da63 LW |
152 | init.parent_names = (parent_name ? &parent_name : NULL); |
153 | init.num_parents = (parent_name ? 1 : 0); | |
91b87a47 | 154 | icst->hw.init = &init; |
a183da63 | 155 | icst->params = pclone; |
7a9ad671 LW |
156 | icst->vcoreg = base + desc->vco_offset; |
157 | icst->lockreg = base + desc->lock_offset; | |
91b87a47 LW |
158 | |
159 | clk = clk_register(dev, &icst->hw); | |
160 | if (IS_ERR(clk)) | |
161 | kfree(icst); | |
162 | ||
163 | return clk; | |
164 | } | |
a218d7fa | 165 | EXPORT_SYMBOL_GPL(icst_clk_register); |