1 // SPDX-License-Identifier: GPL-2.0
2 /***************************************************************************/
3
4 /*
5 * clk.c -- general ColdFire CPU kernel clk handling
6 *
7 * Copyright (C) 2009, Greg Ungerer (gerg@snapgear.com)
8 */
9
10 /***************************************************************************/
11
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/platform_device.h>
15 #include <linux/mutex.h>
16 #include <linux/clk.h>
17 #include <linux/io.h>
18 #include <linux/err.h>
19 #include <asm/coldfire.h>
20 #include <asm/mcfsim.h>
21 #include <asm/mcfclk.h>
22
23 static DEFINE_SPINLOCK(clk_lock);
24
25 #ifdef MCFPM_PPMCR0
26 /*
27 * For more advanced ColdFire parts that have clocks that can be enabled
28 * we supply enable/disable functions. These must properly define their
29 * clocks in their platform specific code.
30 */
__clk_init_enabled(struct clk * clk)31 void __clk_init_enabled(struct clk *clk)
32 {
33 clk->enabled = 1;
34 clk->clk_ops->enable(clk);
35 }
36
__clk_init_disabled(struct clk * clk)37 void __clk_init_disabled(struct clk *clk)
38 {
39 clk->enabled = 0;
40 clk->clk_ops->disable(clk);
41 }
42
__clk_enable0(struct clk * clk)43 static void __clk_enable0(struct clk *clk)
44 {
45 __raw_writeb(clk->slot, MCFPM_PPMCR0);
46 }
47
__clk_disable0(struct clk * clk)48 static void __clk_disable0(struct clk *clk)
49 {
50 __raw_writeb(clk->slot, MCFPM_PPMSR0);
51 }
52
53 struct clk_ops clk_ops0 = {
54 .enable = __clk_enable0,
55 .disable = __clk_disable0,
56 };
57
58 #ifdef MCFPM_PPMCR1
__clk_enable1(struct clk * clk)59 static void __clk_enable1(struct clk *clk)
60 {
61 __raw_writeb(clk->slot, MCFPM_PPMCR1);
62 }
63
__clk_disable1(struct clk * clk)64 static void __clk_disable1(struct clk *clk)
65 {
66 __raw_writeb(clk->slot, MCFPM_PPMSR1);
67 }
68
69 struct clk_ops clk_ops1 = {
70 .enable = __clk_enable1,
71 .disable = __clk_disable1,
72 };
73 #endif /* MCFPM_PPMCR1 */
74 #endif /* MCFPM_PPMCR0 */
75
clk_get(struct device * dev,const char * id)76 struct clk *clk_get(struct device *dev, const char *id)
77 {
78 const char *clk_name = dev ? dev_name(dev) : id ? id : NULL;
79 struct clk *clk;
80 unsigned i;
81
82 for (i = 0; (clk = mcf_clks[i]) != NULL; ++i)
83 if (!strcmp(clk->name, clk_name))
84 return clk;
85 pr_warn("clk_get: didn't find clock %s\n", clk_name);
86 return ERR_PTR(-ENOENT);
87 }
88 EXPORT_SYMBOL(clk_get);
89
clk_enable(struct clk * clk)90 int clk_enable(struct clk *clk)
91 {
92 unsigned long flags;
93 spin_lock_irqsave(&clk_lock, flags);
94 if ((clk->enabled++ == 0) && clk->clk_ops)
95 clk->clk_ops->enable(clk);
96 spin_unlock_irqrestore(&clk_lock, flags);
97
98 return 0;
99 }
100 EXPORT_SYMBOL(clk_enable);
101
clk_disable(struct clk * clk)102 void clk_disable(struct clk *clk)
103 {
104 unsigned long flags;
105
106 if (!clk)
107 return;
108
109 spin_lock_irqsave(&clk_lock, flags);
110 if ((--clk->enabled == 0) && clk->clk_ops)
111 clk->clk_ops->disable(clk);
112 spin_unlock_irqrestore(&clk_lock, flags);
113 }
114 EXPORT_SYMBOL(clk_disable);
115
clk_put(struct clk * clk)116 void clk_put(struct clk *clk)
117 {
118 if (clk->enabled != 0)
119 pr_warn("clk_put %s still enabled\n", clk->name);
120 }
121 EXPORT_SYMBOL(clk_put);
122
clk_get_rate(struct clk * clk)123 unsigned long clk_get_rate(struct clk *clk)
124 {
125 if (!clk)
126 return 0;
127
128 return clk->rate;
129 }
130 EXPORT_SYMBOL(clk_get_rate);
131
132 /* dummy functions, should not be called */
clk_round_rate(struct clk * clk,unsigned long rate)133 long clk_round_rate(struct clk *clk, unsigned long rate)
134 {
135 WARN_ON(clk);
136 return 0;
137 }
138 EXPORT_SYMBOL(clk_round_rate);
139
clk_set_rate(struct clk * clk,unsigned long rate)140 int clk_set_rate(struct clk *clk, unsigned long rate)
141 {
142 WARN_ON(clk);
143 return 0;
144 }
145 EXPORT_SYMBOL(clk_set_rate);
146
clk_set_parent(struct clk * clk,struct clk * parent)147 int clk_set_parent(struct clk *clk, struct clk *parent)
148 {
149 WARN_ON(clk);
150 return 0;
151 }
152 EXPORT_SYMBOL(clk_set_parent);
153
clk_get_parent(struct clk * clk)154 struct clk *clk_get_parent(struct clk *clk)
155 {
156 WARN_ON(clk);
157 return NULL;
158 }
159 EXPORT_SYMBOL(clk_get_parent);
160
161 /***************************************************************************/
162