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authorHeiko Stübner <heiko@sntech.de>2014-07-02 19:58:39 -0400
committerMike Turquette <mturquette@linaro.org>2014-07-13 15:17:06 -0400
commita245fecbb8064641d9cc317b347b5bdb2b7a4bb6 (patch)
treed4573cc7258ecc18e9db839f809960062ee419b0 /drivers/clk/rockchip/clk.c
parent5a994e151f7c54a5fdeb07fe2fed4ed64b9321b8 (diff)
clk: rockchip: add basic infrastructure for clock branches
This adds infrastructure for registering clock branches. On Rockchip SoCs most clock branches are a combination of mux,divider and gate components, thus a composite clock is used when appropriate. Clock branches are supposed to be declared in an array using the COMPOSITE* or MUX, etc makros defined in the header and then registered using rockchip_clk_register_branches. Signed-off-by: Heiko Stuebner <heiko@sntech.de> Acked-By: Max Schwarz <max.schwarz@online.de> Tested-By: Max Schwarz <max.schwarz@online.de> Signed-off-by: Mike Turquette <mturquette@linaro.org>
Diffstat (limited to 'drivers/clk/rockchip/clk.c')
-rw-r--r--drivers/clk/rockchip/clk.c209
1 files changed, 209 insertions, 0 deletions
diff --git a/drivers/clk/rockchip/clk.c b/drivers/clk/rockchip/clk.c
new file mode 100644
index 000000000000..aa15d5ae51d1
--- /dev/null
+++ b/drivers/clk/rockchip/clk.c
@@ -0,0 +1,209 @@
1/*
2 * Copyright (c) 2014 MundoReader S.L.
3 * Author: Heiko Stuebner <heiko@sntech.de>
4 *
5 * based on
6 *
7 * samsung/clk.c
8 * Copyright (c) 2013 Samsung Electronics Co., Ltd.
9 * Copyright (c) 2013 Linaro Ltd.
10 * Author: Thomas Abraham <thomas.ab@samsung.com>
11 *
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2 of the License, or
15 * (at your option) any later version.
16 *
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
21 */
22
23#include <linux/slab.h>
24#include <linux/clk.h>
25#include <linux/clk-provider.h>
26#include "clk.h"
27
28/**
29 * Register a clock branch.
30 * Most clock branches have a form like
31 *
32 * src1 --|--\
33 * |M |--[GATE]-[DIV]-
34 * src2 --|--/
35 *
36 * sometimes without one of those components.
37 */
38struct clk *rockchip_clk_register_branch(const char *name,
39 const char **parent_names, u8 num_parents, void __iomem *base,
40 int muxdiv_offset, u8 mux_shift, u8 mux_width, u8 mux_flags,
41 u8 div_shift, u8 div_width, u8 div_flags,
42 struct clk_div_table *div_table, int gate_offset,
43 u8 gate_shift, u8 gate_flags, unsigned long flags,
44 spinlock_t *lock)
45{
46 struct clk *clk;
47 struct clk_mux *mux = NULL;
48 struct clk_gate *gate = NULL;
49 struct clk_divider *div = NULL;
50 const struct clk_ops *mux_ops = NULL, *div_ops = NULL,
51 *gate_ops = NULL;
52
53 if (num_parents > 1) {
54 mux = kzalloc(sizeof(*mux), GFP_KERNEL);
55 if (!mux)
56 return ERR_PTR(-ENOMEM);
57
58 mux->reg = base + muxdiv_offset;
59 mux->shift = mux_shift;
60 mux->mask = BIT(mux_width) - 1;
61 mux->flags = mux_flags;
62 mux->lock = lock;
63 mux_ops = (mux_flags & CLK_MUX_READ_ONLY) ? &clk_mux_ro_ops
64 : &clk_mux_ops;
65 }
66
67 if (gate_offset >= 0) {
68 gate = kzalloc(sizeof(*gate), GFP_KERNEL);
69 if (!gate)
70 return ERR_PTR(-ENOMEM);
71
72 gate->flags = gate_flags;
73 gate->reg = base + gate_offset;
74 gate->bit_idx = gate_shift;
75 gate->lock = lock;
76 gate_ops = &clk_gate_ops;
77 }
78
79 if (div_width > 0) {
80 div = kzalloc(sizeof(*div), GFP_KERNEL);
81 if (!div)
82 return ERR_PTR(-ENOMEM);
83
84 div->flags = div_flags;
85 div->reg = base + muxdiv_offset;
86 div->shift = div_shift;
87 div->width = div_width;
88 div->lock = lock;
89 div->table = div_table;
90 div_ops = (div_flags & CLK_DIVIDER_READ_ONLY)
91 ? &clk_divider_ro_ops
92 : &clk_divider_ops;
93 }
94
95 clk = clk_register_composite(NULL, name, parent_names, num_parents,
96 mux ? &mux->hw : NULL, mux_ops,
97 div ? &div->hw : NULL, div_ops,
98 gate ? &gate->hw : NULL, gate_ops,
99 flags);
100
101 return clk;
102}
103
104static DEFINE_SPINLOCK(clk_lock);
105static struct clk **clk_table;
106static void __iomem *reg_base;
107static struct clk_onecell_data clk_data;
108
109void __init rockchip_clk_init(struct device_node *np, void __iomem *base,
110 unsigned long nr_clks)
111{
112 reg_base = base;
113
114 clk_table = kcalloc(nr_clks, sizeof(struct clk *), GFP_KERNEL);
115 if (!clk_table)
116 pr_err("%s: could not allocate clock lookup table\n", __func__);
117
118 clk_data.clks = clk_table;
119 clk_data.clk_num = nr_clks;
120 of_clk_add_provider(np, of_clk_src_onecell_get, &clk_data);
121}
122
123void rockchip_clk_add_lookup(struct clk *clk, unsigned int id)
124{
125 if (clk_table && id)
126 clk_table[id] = clk;
127}
128
129void __init rockchip_clk_register_branches(
130 struct rockchip_clk_branch *list,
131 unsigned int nr_clk)
132{
133 struct clk *clk = NULL;
134 unsigned int idx;
135 unsigned long flags;
136
137 for (idx = 0; idx < nr_clk; idx++, list++) {
138 flags = list->flags;
139
140 /* catch simple muxes */
141 switch (list->branch_type) {
142 case branch_mux:
143 clk = clk_register_mux(NULL, list->name,
144 list->parent_names, list->num_parents,
145 flags, reg_base + list->muxdiv_offset,
146 list->mux_shift, list->mux_width,
147 list->mux_flags, &clk_lock);
148 break;
149 case branch_divider:
150 if (list->div_table)
151 clk = clk_register_divider_table(NULL,
152 list->name, list->parent_names[0],
153 flags, reg_base + list->muxdiv_offset,
154 list->div_shift, list->div_width,
155 list->div_flags, list->div_table,
156 &clk_lock);
157 else
158 clk = clk_register_divider(NULL, list->name,
159 list->parent_names[0], flags,
160 reg_base + list->muxdiv_offset,
161 list->div_shift, list->div_width,
162 list->div_flags, &clk_lock);
163 break;
164 case branch_fraction_divider:
165 /* unimplemented */
166 continue;
167 break;
168 case branch_gate:
169 flags |= CLK_SET_RATE_PARENT;
170
171 /* keep all gates untouched for now */
172 flags |= CLK_IGNORE_UNUSED;
173
174 clk = clk_register_gate(NULL, list->name,
175 list->parent_names[0], flags,
176 reg_base + list->gate_offset,
177 list->gate_shift, list->gate_flags, &clk_lock);
178 break;
179 case branch_composite:
180 /* keep all gates untouched for now */
181 flags |= CLK_IGNORE_UNUSED;
182
183 clk = rockchip_clk_register_branch(list->name,
184 list->parent_names, list->num_parents,
185 reg_base, list->muxdiv_offset, list->mux_shift,
186 list->mux_width, list->mux_flags,
187 list->div_shift, list->div_width,
188 list->div_flags, list->div_table,
189 list->gate_offset, list->gate_shift,
190 list->gate_flags, flags, &clk_lock);
191 break;
192 }
193
194 /* none of the cases above matched */
195 if (!clk) {
196 pr_err("%s: unknown clock type %d\n",
197 __func__, list->branch_type);
198 continue;
199 }
200
201 if (IS_ERR(clk)) {
202 pr_err("%s: failed to register clock %s: %ld\n",
203 __func__, list->name, PTR_ERR(clk));
204 continue;
205 }
206
207 rockchip_clk_add_lookup(clk, list->id);
208 }
209}
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