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c0db2ea4 JB |
1 | /* |
2 | * Based on arch/arm/plat-omap/clock.c | |
3 | * | |
4 | * Copyright (C) 2004 - 2005 Nokia corporation | |
5 | * Written by Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com> | |
6 | * Modified for omap shared clock framework by Tony Lindgren <tony@atomide.com> | |
7 | * Copyright 2007 Freescale Semiconductor, Inc. All Rights Reserved. | |
8 | * Copyright 2008 Juergen Beisert, kernel@pengutronix.de | |
9 | * | |
10 | * This program is free software; you can redistribute it and/or | |
11 | * modify it under the terms of the GNU General Public License | |
12 | * as published by the Free Software Foundation; either version 2 | |
13 | * of the License, or (at your option) any later version. | |
14 | * This program is distributed in the hope that it will be useful, | |
15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
17 | * GNU General Public License for more details. | |
18 | * | |
19 | * You should have received a copy of the GNU General Public License | |
20 | * along with this program; if not, write to the Free Software | |
21 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, | |
22 | * MA 02110-1301, USA. | |
23 | */ | |
24 | ||
25 | /* #define DEBUG */ | |
26 | ||
27 | #include <linux/clk.h> | |
28 | #include <linux/err.h> | |
29 | #include <linux/errno.h> | |
30 | #include <linux/init.h> | |
31 | #include <linux/io.h> | |
32 | #include <linux/kernel.h> | |
33 | #include <linux/list.h> | |
34 | #include <linux/module.h> | |
35 | #include <linux/mutex.h> | |
36 | #include <linux/platform_device.h> | |
37 | #include <linux/proc_fs.h> | |
38 | #include <linux/semaphore.h> | |
39 | #include <linux/string.h> | |
c0db2ea4 | 40 | |
a09e64fb | 41 | #include <mach/clock.h> |
6d73665f | 42 | #include <mach/hardware.h> |
c0db2ea4 JB |
43 | |
44 | static LIST_HEAD(clocks); | |
45 | static DEFINE_MUTEX(clocks_mutex); | |
46 | ||
47 | /*------------------------------------------------------------------------- | |
48 | * Standard clock functions defined in include/linux/clk.h | |
49 | *-------------------------------------------------------------------------*/ | |
50 | ||
c0db2ea4 JB |
51 | static void __clk_disable(struct clk *clk) |
52 | { | |
53 | if (clk == NULL || IS_ERR(clk)) | |
54 | return; | |
8ac5b7c5 | 55 | WARN_ON(!clk->usecount); |
9b839ec0 AK |
56 | |
57 | if (!(--clk->usecount)) { | |
58 | if (clk->disable) | |
59 | clk->disable(clk); | |
60 | __clk_disable(clk->parent); | |
61 | __clk_disable(clk->secondary); | |
62 | } | |
c0db2ea4 JB |
63 | } |
64 | ||
65 | static int __clk_enable(struct clk *clk) | |
66 | { | |
67 | if (clk == NULL || IS_ERR(clk)) | |
68 | return -EINVAL; | |
69 | ||
9b839ec0 AK |
70 | if (clk->usecount++ == 0) { |
71 | __clk_enable(clk->parent); | |
72 | __clk_enable(clk->secondary); | |
c0db2ea4 | 73 | |
9b839ec0 AK |
74 | if (clk->enable) |
75 | clk->enable(clk); | |
76 | } | |
c0db2ea4 JB |
77 | return 0; |
78 | } | |
79 | ||
80 | /* This function increments the reference count on the clock and enables the | |
81 | * clock if not already enabled. The parent clock tree is recursively enabled | |
82 | */ | |
83 | int clk_enable(struct clk *clk) | |
84 | { | |
85 | int ret = 0; | |
86 | ||
87 | if (clk == NULL || IS_ERR(clk)) | |
88 | return -EINVAL; | |
89 | ||
90 | mutex_lock(&clocks_mutex); | |
91 | ret = __clk_enable(clk); | |
92 | mutex_unlock(&clocks_mutex); | |
93 | ||
94 | return ret; | |
95 | } | |
96 | EXPORT_SYMBOL(clk_enable); | |
97 | ||
98 | /* This function decrements the reference count on the clock and disables | |
99 | * the clock when reference count is 0. The parent clock tree is | |
100 | * recursively disabled | |
101 | */ | |
102 | void clk_disable(struct clk *clk) | |
103 | { | |
104 | if (clk == NULL || IS_ERR(clk)) | |
105 | return; | |
106 | ||
107 | mutex_lock(&clocks_mutex); | |
108 | __clk_disable(clk); | |
109 | mutex_unlock(&clocks_mutex); | |
110 | } | |
111 | EXPORT_SYMBOL(clk_disable); | |
112 | ||
113 | /* Retrieve the *current* clock rate. If the clock itself | |
114 | * does not provide a special calculation routine, ask | |
115 | * its parent and so on, until one is able to return | |
116 | * a valid clock rate | |
117 | */ | |
118 | unsigned long clk_get_rate(struct clk *clk) | |
119 | { | |
120 | if (clk == NULL || IS_ERR(clk)) | |
121 | return 0UL; | |
122 | ||
123 | if (clk->get_rate) | |
124 | return clk->get_rate(clk); | |
125 | ||
126 | return clk_get_rate(clk->parent); | |
127 | } | |
128 | EXPORT_SYMBOL(clk_get_rate); | |
129 | ||
c0db2ea4 JB |
130 | /* Round the requested clock rate to the nearest supported |
131 | * rate that is less than or equal to the requested rate. | |
132 | * This is dependent on the clock's current parent. | |
133 | */ | |
134 | long clk_round_rate(struct clk *clk, unsigned long rate) | |
135 | { | |
136 | if (clk == NULL || IS_ERR(clk) || !clk->round_rate) | |
137 | return 0; | |
138 | ||
139 | return clk->round_rate(clk, rate); | |
140 | } | |
141 | EXPORT_SYMBOL(clk_round_rate); | |
142 | ||
143 | /* Set the clock to the requested clock rate. The rate must | |
144 | * match a supported rate exactly based on what clk_round_rate returns | |
145 | */ | |
146 | int clk_set_rate(struct clk *clk, unsigned long rate) | |
147 | { | |
148 | int ret = -EINVAL; | |
149 | ||
150 | if (clk == NULL || IS_ERR(clk) || clk->set_rate == NULL || rate == 0) | |
151 | return ret; | |
152 | ||
153 | mutex_lock(&clocks_mutex); | |
154 | ret = clk->set_rate(clk, rate); | |
155 | mutex_unlock(&clocks_mutex); | |
156 | ||
157 | return ret; | |
158 | } | |
159 | EXPORT_SYMBOL(clk_set_rate); | |
160 | ||
161 | /* Set the clock's parent to another clock source */ | |
162 | int clk_set_parent(struct clk *clk, struct clk *parent) | |
163 | { | |
164 | int ret = -EINVAL; | |
9b839ec0 | 165 | struct clk *old; |
c0db2ea4 JB |
166 | |
167 | if (clk == NULL || IS_ERR(clk) || parent == NULL || | |
168 | IS_ERR(parent) || clk->set_parent == NULL) | |
169 | return ret; | |
170 | ||
9b839ec0 AK |
171 | if (clk->usecount) |
172 | clk_enable(parent); | |
173 | ||
c0db2ea4 JB |
174 | mutex_lock(&clocks_mutex); |
175 | ret = clk->set_parent(clk, parent); | |
9b839ec0 AK |
176 | if (ret == 0) { |
177 | old = clk->parent; | |
c0db2ea4 | 178 | clk->parent = parent; |
9b839ec0 AK |
179 | } else { |
180 | old = parent; | |
181 | } | |
c0db2ea4 JB |
182 | mutex_unlock(&clocks_mutex); |
183 | ||
9b839ec0 AK |
184 | if (clk->usecount) |
185 | clk_disable(old); | |
186 | ||
c0db2ea4 JB |
187 | return ret; |
188 | } | |
189 | EXPORT_SYMBOL(clk_set_parent); | |
190 | ||
191 | /* Retrieve the clock's parent clock source */ | |
192 | struct clk *clk_get_parent(struct clk *clk) | |
193 | { | |
194 | struct clk *ret = NULL; | |
195 | ||
196 | if (clk == NULL || IS_ERR(clk)) | |
197 | return ret; | |
198 | ||
199 | return clk->parent; | |
200 | } | |
201 | EXPORT_SYMBOL(clk_get_parent); | |
202 | ||
a2865197 SH |
203 | /* |
204 | * Get the resulting clock rate from a PLL register value and the input | |
205 | * frequency. PLLs with this register layout can at least be found on | |
206 | * MX1, MX21, MX27 and MX31 | |
207 | * | |
208 | * mfi + mfn / (mfd + 1) | |
209 | * f = 2 * f_ref * -------------------- | |
210 | * pd + 1 | |
211 | */ | |
212 | unsigned long mxc_decode_pll(unsigned int reg_val, u32 freq) | |
213 | { | |
214 | long long ll; | |
215 | int mfn_abs; | |
216 | unsigned int mfi, mfn, mfd, pd; | |
217 | ||
218 | mfi = (reg_val >> 10) & 0xf; | |
219 | mfn = reg_val & 0x3ff; | |
220 | mfd = (reg_val >> 16) & 0x3ff; | |
221 | pd = (reg_val >> 26) & 0xf; | |
222 | ||
223 | mfi = mfi <= 5 ? 5 : mfi; | |
224 | ||
225 | mfn_abs = mfn; | |
226 | ||
6d73665f SH |
227 | /* On all i.MXs except i.MX1 and i.MX21 mfn is a 10bit |
228 | * 2's complements number | |
229 | */ | |
230 | if (!cpu_is_mx1() && !cpu_is_mx21() && mfn >= 0x200) | |
231 | mfn_abs = 0x400 - mfn; | |
a2865197 SH |
232 | |
233 | freq *= 2; | |
234 | freq /= pd + 1; | |
235 | ||
236 | ll = (unsigned long long)freq * mfn_abs; | |
237 | ||
238 | do_div(ll, mfd + 1); | |
6d73665f SH |
239 | |
240 | if (!cpu_is_mx1() && !cpu_is_mx21() && mfn >= 0x200) | |
a2865197 | 241 | ll = -ll; |
6d73665f | 242 | |
a2865197 SH |
243 | ll = (freq * mfi) + ll; |
244 | ||
245 | return ll; | |
246 | } |