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clk-busy.c
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1 /*
2  * Copyright 2012 Freescale Semiconductor, Inc.
3  * Copyright 2012 Linaro Ltd.
4  *
5  * The code contained herein is licensed under the GNU General Public
6  * License. You may obtain a copy of the GNU General Public License
7  * Version 2 or later at the following locations:
8  *
9  * http://www.opensource.org/licenses/gpl-license.html
10  * http://www.gnu.org/copyleft/gpl.html
11  */
12 
13 #include <linux/clk.h>
14 #include <linux/clk-provider.h>
15 #include <linux/io.h>
16 #include <linux/slab.h>
17 #include <linux/jiffies.h>
18 #include <linux/err.h>
19 #include "clk.h"
20 
21 static int clk_busy_wait(void __iomem *reg, u8 shift)
22 {
23  unsigned long timeout = jiffies + msecs_to_jiffies(10);
24 
25  while (readl_relaxed(reg) & (1 << shift))
26  if (time_after(jiffies, timeout))
27  return -ETIMEDOUT;
28 
29  return 0;
30 }
31 
33  struct clk_divider div;
34  const struct clk_ops *div_ops;
35  void __iomem *reg;
37 };
38 
39 static inline struct clk_busy_divider *to_clk_busy_divider(struct clk_hw *hw)
40 {
41  struct clk_divider *div = container_of(hw, struct clk_divider, hw);
42 
43  return container_of(div, struct clk_busy_divider, div);
44 }
45 
46 static unsigned long clk_busy_divider_recalc_rate(struct clk_hw *hw,
47  unsigned long parent_rate)
48 {
49  struct clk_busy_divider *busy = to_clk_busy_divider(hw);
50 
51  return busy->div_ops->recalc_rate(&busy->div.hw, parent_rate);
52 }
53 
54 static long clk_busy_divider_round_rate(struct clk_hw *hw, unsigned long rate,
55  unsigned long *prate)
56 {
57  struct clk_busy_divider *busy = to_clk_busy_divider(hw);
58 
59  return busy->div_ops->round_rate(&busy->div.hw, rate, prate);
60 }
61 
62 static int clk_busy_divider_set_rate(struct clk_hw *hw, unsigned long rate,
63  unsigned long parent_rate)
64 {
65  struct clk_busy_divider *busy = to_clk_busy_divider(hw);
66  int ret;
67 
68  ret = busy->div_ops->set_rate(&busy->div.hw, rate, parent_rate);
69  if (!ret)
70  ret = clk_busy_wait(busy->reg, busy->shift);
71 
72  return ret;
73 }
74 
75 static struct clk_ops clk_busy_divider_ops = {
76  .recalc_rate = clk_busy_divider_recalc_rate,
77  .round_rate = clk_busy_divider_round_rate,
78  .set_rate = clk_busy_divider_set_rate,
79 };
80 
81 struct clk *imx_clk_busy_divider(const char *name, const char *parent_name,
82  void __iomem *reg, u8 shift, u8 width,
83  void __iomem *busy_reg, u8 busy_shift)
84 {
85  struct clk_busy_divider *busy;
86  struct clk *clk;
87  struct clk_init_data init;
88 
89  busy = kzalloc(sizeof(*busy), GFP_KERNEL);
90  if (!busy)
91  return ERR_PTR(-ENOMEM);
92 
93  busy->reg = busy_reg;
94  busy->shift = busy_shift;
95 
96  busy->div.reg = reg;
97  busy->div.shift = shift;
98  busy->div.width = width;
99  busy->div.lock = &imx_ccm_lock;
100  busy->div_ops = &clk_divider_ops;
101 
102  init.name = name;
103  init.ops = &clk_busy_divider_ops;
104  init.flags = CLK_SET_RATE_PARENT;
105  init.parent_names = &parent_name;
106  init.num_parents = 1;
107 
108  busy->div.hw.init = &init;
109 
110  clk = clk_register(NULL, &busy->div.hw);
111  if (IS_ERR(clk))
112  kfree(busy);
113 
114  return clk;
115 }
116 
117 struct clk_busy_mux {
118  struct clk_mux mux;
119  const struct clk_ops *mux_ops;
120  void __iomem *reg;
122 };
123 
124 static inline struct clk_busy_mux *to_clk_busy_mux(struct clk_hw *hw)
125 {
126  struct clk_mux *mux = container_of(hw, struct clk_mux, hw);
127 
128  return container_of(mux, struct clk_busy_mux, mux);
129 }
130 
131 static u8 clk_busy_mux_get_parent(struct clk_hw *hw)
132 {
133  struct clk_busy_mux *busy = to_clk_busy_mux(hw);
134 
135  return busy->mux_ops->get_parent(&busy->mux.hw);
136 }
137 
138 static int clk_busy_mux_set_parent(struct clk_hw *hw, u8 index)
139 {
140  struct clk_busy_mux *busy = to_clk_busy_mux(hw);
141  int ret;
142 
143  ret = busy->mux_ops->set_parent(&busy->mux.hw, index);
144  if (!ret)
145  ret = clk_busy_wait(busy->reg, busy->shift);
146 
147  return ret;
148 }
149 
151  .get_parent = clk_busy_mux_get_parent,
152  .set_parent = clk_busy_mux_set_parent,
153 };
154 
155 struct clk *imx_clk_busy_mux(const char *name, void __iomem *reg, u8 shift,
156  u8 width, void __iomem *busy_reg, u8 busy_shift,
157  const char **parent_names, int num_parents)
158 {
159  struct clk_busy_mux *busy;
160  struct clk *clk;
161  struct clk_init_data init;
162 
163  busy = kzalloc(sizeof(*busy), GFP_KERNEL);
164  if (!busy)
165  return ERR_PTR(-ENOMEM);
166 
167  busy->reg = busy_reg;
168  busy->shift = busy_shift;
169 
170  busy->mux.reg = reg;
171  busy->mux.shift = shift;
172  busy->mux.width = width;
173  busy->mux.lock = &imx_ccm_lock;
174  busy->mux_ops = &clk_mux_ops;
175 
176  init.name = name;
177  init.ops = &clk_busy_mux_ops;
178  init.flags = 0;
179  init.parent_names = parent_names;
180  init.num_parents = num_parents;
181 
182  busy->mux.hw.init = &init;
183 
184  clk = clk_register(NULL, &busy->mux.hw);
185  if (IS_ERR(clk))
186  kfree(busy);
187 
188  return clk;
189 }