1 /*****************************************************************************
2 * Copyright 2001 - 2009 Broadcom Corporation. All rights reserved.
3 *
4 * Unless you and Broadcom execute a separate written software license
5 * agreement governing use of this software, this software is licensed to you
6 * under the terms of the GNU General Public License version 2, available at
7 * http://www.broadcom.com/licenses/GPLv2.php (the "GPL").
8 *
9 * Notwithstanding the above, under no circumstances may you combine this
10 * software in any way with any other Broadcom software provided under a
11 * license other than the GPL, without Broadcom's express prior written
12 * consent.
13 *****************************************************************************/
14
15 #include <linux/module.h>
16 #include <linux/kernel.h>
17 #include <linux/device.h>
18 #include <linux/list.h>
19 #include <linux/errno.h>
20 #include <linux/err.h>
21 #include <linux/string.h>
22 #include <linux/clk.h>
23 #include <linux/spinlock.h>
24 #include <linux/clkdev.h>
25 #include <mach/csp/hw_cfg.h>
26 #include <mach/csp/chipcHw_def.h>
27 #include <mach/csp/chipcHw_reg.h>
28 #include <mach/csp/chipcHw_inline.h>
29
30 #include "clock.h"
31
32 #define clk_is_primary(x) ((x)->type & CLK_TYPE_PRIMARY)
33 #define clk_is_pll1(x) ((x)->type & CLK_TYPE_PLL1)
34 #define clk_is_pll2(x) ((x)->type & CLK_TYPE_PLL2)
35 #define clk_is_programmable(x) ((x)->type & CLK_TYPE_PROGRAMMABLE)
36 #define clk_is_bypassable(x) ((x)->type & CLK_TYPE_BYPASSABLE)
37
38 #define clk_is_using_xtal(x) ((x)->mode & CLK_MODE_XTAL)
39
40 static DEFINE_SPINLOCK(clk_lock);
41
__clk_enable(struct clk * clk)42 static void __clk_enable(struct clk *clk)
43 {
44 if (!clk)
45 return;
46
47 /* enable parent clock first */
48 if (clk->parent)
49 __clk_enable(clk->parent);
50
51 if (clk->use_cnt++ == 0) {
52 if (clk_is_pll1(clk)) { /* PLL1 */
53 chipcHw_pll1Enable(clk->rate_hz, 0);
54 } else if (clk_is_pll2(clk)) { /* PLL2 */
55 chipcHw_pll2Enable(clk->rate_hz);
56 } else if (clk_is_using_xtal(clk)) { /* source is crystal */
57 if (!clk_is_primary(clk))
58 chipcHw_bypassClockEnable(clk->csp_id);
59 } else { /* source is PLL */
60 chipcHw_setClockEnable(clk->csp_id);
61 }
62 }
63 }
64
clk_enable(struct clk * clk)65 int clk_enable(struct clk *clk)
66 {
67 unsigned long flags;
68
69 if (!clk)
70 return -EINVAL;
71
72 spin_lock_irqsave(&clk_lock, flags);
73 __clk_enable(clk);
74 spin_unlock_irqrestore(&clk_lock, flags);
75
76 return 0;
77 }
78 EXPORT_SYMBOL(clk_enable);
79
__clk_disable(struct clk * clk)80 static void __clk_disable(struct clk *clk)
81 {
82 if (!clk)
83 return;
84
85 BUG_ON(clk->use_cnt == 0);
86
87 if (--clk->use_cnt == 0) {
88 if (clk_is_pll1(clk)) { /* PLL1 */
89 chipcHw_pll1Disable();
90 } else if (clk_is_pll2(clk)) { /* PLL2 */
91 chipcHw_pll2Disable();
92 } else if (clk_is_using_xtal(clk)) { /* source is crystal */
93 if (!clk_is_primary(clk))
94 chipcHw_bypassClockDisable(clk->csp_id);
95 } else { /* source is PLL */
96 chipcHw_setClockDisable(clk->csp_id);
97 }
98 }
99
100 if (clk->parent)
101 __clk_disable(clk->parent);
102 }
103
clk_disable(struct clk * clk)104 void clk_disable(struct clk *clk)
105 {
106 unsigned long flags;
107
108 if (!clk)
109 return;
110
111 spin_lock_irqsave(&clk_lock, flags);
112 __clk_disable(clk);
113 spin_unlock_irqrestore(&clk_lock, flags);
114 }
115 EXPORT_SYMBOL(clk_disable);
116
clk_get_rate(struct clk * clk)117 unsigned long clk_get_rate(struct clk *clk)
118 {
119 if (!clk)
120 return 0;
121
122 return clk->rate_hz;
123 }
124 EXPORT_SYMBOL(clk_get_rate);
125
clk_round_rate(struct clk * clk,unsigned long rate)126 long clk_round_rate(struct clk *clk, unsigned long rate)
127 {
128 unsigned long flags;
129 unsigned long actual;
130 unsigned long rate_hz;
131
132 if (!clk)
133 return -EINVAL;
134
135 if (!clk_is_programmable(clk))
136 return -EINVAL;
137
138 if (clk->use_cnt)
139 return -EBUSY;
140
141 spin_lock_irqsave(&clk_lock, flags);
142 actual = clk->parent->rate_hz;
143 rate_hz = min(actual, rate);
144 spin_unlock_irqrestore(&clk_lock, flags);
145
146 return rate_hz;
147 }
148 EXPORT_SYMBOL(clk_round_rate);
149
clk_set_rate(struct clk * clk,unsigned long rate)150 int clk_set_rate(struct clk *clk, unsigned long rate)
151 {
152 unsigned long flags;
153 unsigned long actual;
154 unsigned long rate_hz;
155
156 if (!clk)
157 return -EINVAL;
158
159 if (!clk_is_programmable(clk))
160 return -EINVAL;
161
162 if (clk->use_cnt)
163 return -EBUSY;
164
165 spin_lock_irqsave(&clk_lock, flags);
166 actual = clk->parent->rate_hz;
167 rate_hz = min(actual, rate);
168 rate_hz = chipcHw_setClockFrequency(clk->csp_id, rate_hz);
169 clk->rate_hz = rate_hz;
170 spin_unlock_irqrestore(&clk_lock, flags);
171
172 return 0;
173 }
174 EXPORT_SYMBOL(clk_set_rate);
175
clk_get_parent(struct clk * clk)176 struct clk *clk_get_parent(struct clk *clk)
177 {
178 if (!clk)
179 return NULL;
180
181 return clk->parent;
182 }
183 EXPORT_SYMBOL(clk_get_parent);
184
clk_set_parent(struct clk * clk,struct clk * parent)185 int clk_set_parent(struct clk *clk, struct clk *parent)
186 {
187 unsigned long flags;
188 struct clk *old_parent;
189
190 if (!clk || !parent)
191 return -EINVAL;
192
193 if (!clk_is_primary(parent) || !clk_is_bypassable(clk))
194 return -EINVAL;
195
196 /* if more than one user, parent is not allowed */
197 if (clk->use_cnt > 1)
198 return -EBUSY;
199
200 if (clk->parent == parent)
201 return 0;
202
203 spin_lock_irqsave(&clk_lock, flags);
204 old_parent = clk->parent;
205 clk->parent = parent;
206 if (clk_is_using_xtal(parent))
207 clk->mode |= CLK_MODE_XTAL;
208 else
209 clk->mode &= (~CLK_MODE_XTAL);
210
211 /* if clock is active */
212 if (clk->use_cnt != 0) {
213 clk->use_cnt--;
214 /* enable clock with the new parent */
215 __clk_enable(clk);
216 /* disable the old parent */
217 __clk_disable(old_parent);
218 }
219 spin_unlock_irqrestore(&clk_lock, flags);
220
221 return 0;
222 }
223 EXPORT_SYMBOL(clk_set_parent);
224