FreeBSD/Linux Kernel Cross Reference
sys/arm/ti/ti_prcm.c
1 /*
2 * Copyright (c) 2010
3 * Ben Gray <ben.r.gray@gmail.com>.
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. All advertising materials mentioning features or use of this software
15 * must display the following acknowledgement:
16 * This product includes software developed by Ben Gray.
17 * 4. The name of the company nor the name of the author may be used to
18 * endorse or promote products derived from this software without specific
19 * prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY BEN GRAY ``AS IS'' AND ANY EXPRESS OR
22 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
23 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
24 * IN NO EVENT SHALL BEN GRAY BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
25 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
26 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
27 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
28 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
29 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
30 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31 */
32
33 /**
34 * Power, Reset and Clock Managment Module
35 *
36 * This is a very simple driver wrapper around the PRCM set of registers in
37 * the OMAP3 chip. It allows you to turn on and off things like the functional
38 * and interface clocks to the various on-chip modules.
39 *
40 */
41 #include <sys/cdefs.h>
42 __FBSDID("$FreeBSD: releng/10.1/sys/arm/ti/ti_prcm.c 259329 2013-12-13 20:43:11Z ian $");
43
44 #include <sys/param.h>
45 #include <sys/systm.h>
46 #include <sys/kernel.h>
47 #include <sys/module.h>
48 #include <sys/bus.h>
49 #include <sys/resource.h>
50 #include <sys/rman.h>
51 #include <sys/lock.h>
52 #include <sys/mutex.h>
53
54 #include <machine/bus.h>
55 #include <machine/cpu.h>
56 #include <machine/cpufunc.h>
57 #include <machine/resource.h>
58 #include <machine/intr.h>
59
60 #include <arm/ti/ti_prcm.h>
61
62 /**
63 * ti_clk_devmap - Array of clock devices, should be defined one per SoC
64 *
65 * This array is typically defined in one of the targeted *_prcm_clk.c
66 * files and is specific to the given SoC platform. Each entry in the array
67 * corresponds to an individual clock device.
68 */
69 extern struct ti_clock_dev ti_clk_devmap[];
70
71 /**
72 * ti_prcm_clk_dev - returns a pointer to the clock device with given id
73 * @clk: the ID of the clock device to get
74 *
75 * Simply iterates through the clk_devmap global array and returns a pointer
76 * to the clock device if found.
77 *
78 * LOCKING:
79 * None
80 *
81 * RETURNS:
82 * The pointer to the clock device on success, on failure NULL is returned.
83 */
84 static struct ti_clock_dev *
85 ti_prcm_clk_dev(clk_ident_t clk)
86 {
87 struct ti_clock_dev *clk_dev;
88
89 /* Find the clock within the devmap - it's a bit inefficent having a for
90 * loop for this, but this function should only called when a driver is
91 * being activated so IMHO not a big issue.
92 */
93 clk_dev = &(ti_clk_devmap[0]);
94 while (clk_dev->id != INVALID_CLK_IDENT) {
95 if (clk_dev->id == clk) {
96 return (clk_dev);
97 }
98 clk_dev++;
99 }
100
101 /* Sanity check we managed to find the clock */
102 printf("ti_prcm: Failed to find clock device (%d)\n", clk);
103 return (NULL);
104 }
105
106 /**
107 * ti_prcm_clk_valid - enables a clock for a particular module
108 * @clk: identifier for the module to enable, see ti_prcm.h for a list
109 * of possible modules.
110 * Example: OMAP3_MODULE_MMC1_ICLK or OMAP3_MODULE_GPTIMER10_FCLK.
111 *
112 * This function can enable either a functional or interface clock.
113 *
114 * The real work done to enable the clock is really done in the callback
115 * function associated with the clock, this function is simply a wrapper
116 * around that.
117 *
118 * LOCKING:
119 * Internally locks the driver context.
120 *
121 * RETURNS:
122 * Returns 0 on success or positive error code on failure.
123 */
124 int
125 ti_prcm_clk_valid(clk_ident_t clk)
126 {
127 int ret = 0;
128
129 if (ti_prcm_clk_dev(clk) == NULL)
130 ret = EINVAL;
131
132 return (ret);
133 }
134
135
136 /**
137 * ti_prcm_clk_enable - enables a clock for a particular module
138 * @clk: identifier for the module to enable, see ti_prcm.h for a list
139 * of possible modules.
140 * Example: OMAP3_MODULE_MMC1_ICLK or OMAP3_MODULE_GPTIMER10_FCLK.
141 *
142 * This function can enable either a functional or interface clock.
143 *
144 * The real work done to enable the clock is really done in the callback
145 * function associated with the clock, this function is simply a wrapper
146 * around that.
147 *
148 * LOCKING:
149 * Internally locks the driver context.
150 *
151 * RETURNS:
152 * Returns 0 on success or positive error code on failure.
153 */
154 int
155 ti_prcm_clk_enable(clk_ident_t clk)
156 {
157 struct ti_clock_dev *clk_dev;
158 int ret;
159
160 /* Find the clock within the devmap - it's a bit inefficent having a for
161 * loop for this, but this function should only called when a driver is
162 * being activated so IMHO not a big issue.
163 */
164 clk_dev = ti_prcm_clk_dev(clk);
165
166 /* Sanity check we managed to find the clock */
167 if (clk_dev == NULL)
168 return (EINVAL);
169
170 /* Activate the clock */
171 if (clk_dev->clk_activate)
172 ret = clk_dev->clk_activate(clk_dev);
173 else
174 ret = EINVAL;
175
176 return (ret);
177 }
178
179
180 /**
181 * ti_prcm_clk_disable - disables a clock for a particular module
182 * @clk: identifier for the module to enable, see ti_prcm.h for a list
183 * of possible modules.
184 * Example: OMAP3_MODULE_MMC1_ICLK or OMAP3_MODULE_GPTIMER10_FCLK.
185 *
186 * This function can enable either a functional or interface clock.
187 *
188 * The real work done to enable the clock is really done in the callback
189 * function associated with the clock, this function is simply a wrapper
190 * around that.
191 *
192 * LOCKING:
193 * Internally locks the driver context.
194 *
195 * RETURNS:
196 * Returns 0 on success or positive error code on failure.
197 */
198 int
199 ti_prcm_clk_disable(clk_ident_t clk)
200 {
201 struct ti_clock_dev *clk_dev;
202 int ret;
203
204 /* Find the clock within the devmap - it's a bit inefficent having a for
205 * loop for this, but this function should only called when a driver is
206 * being activated so IMHO not a big issue.
207 */
208 clk_dev = ti_prcm_clk_dev(clk);
209
210 /* Sanity check we managed to find the clock */
211 if (clk_dev == NULL)
212 return (EINVAL);
213
214 /* Activate the clock */
215 if (clk_dev->clk_deactivate)
216 ret = clk_dev->clk_deactivate(clk_dev);
217 else
218 ret = EINVAL;
219
220 return (ret);
221 }
222
223 /**
224 * ti_prcm_clk_set_source - sets the source
225 * @clk: identifier for the module to enable, see ti_prcm.h for a list
226 * of possible modules.
227 * Example: OMAP3_MODULE_MMC1_ICLK or OMAP3_MODULE_GPTIMER10_FCLK.
228 *
229 * This function can enable either a functional or interface clock.
230 *
231 * The real work done to enable the clock is really done in the callback
232 * function associated with the clock, this function is simply a wrapper
233 * around that.
234 *
235 * LOCKING:
236 * Internally locks the driver context.
237 *
238 * RETURNS:
239 * Returns 0 on success or positive error code on failure.
240 */
241 int
242 ti_prcm_clk_set_source(clk_ident_t clk, clk_src_t clksrc)
243 {
244 struct ti_clock_dev *clk_dev;
245 int ret;
246
247 /* Find the clock within the devmap - it's a bit inefficent having a for
248 * loop for this, but this function should only called when a driver is
249 * being activated so IMHO not a big issue.
250 */
251 clk_dev = ti_prcm_clk_dev(clk);
252
253 /* Sanity check we managed to find the clock */
254 if (clk_dev == NULL)
255 return (EINVAL);
256
257 /* Activate the clock */
258 if (clk_dev->clk_set_source)
259 ret = clk_dev->clk_set_source(clk_dev, clksrc);
260 else
261 ret = EINVAL;
262
263 return (ret);
264 }
265
266
267 /**
268 * ti_prcm_clk_get_source_freq - gets the source clock frequency
269 * @clk: identifier for the module to enable, see ti_prcm.h for a list
270 * of possible modules.
271 * @freq: pointer to an integer that upon return will contain the src freq
272 *
273 * This function returns the frequency of the source clock.
274 *
275 * The real work done to enable the clock is really done in the callback
276 * function associated with the clock, this function is simply a wrapper
277 * around that.
278 *
279 * LOCKING:
280 * Internally locks the driver context.
281 *
282 * RETURNS:
283 * Returns 0 on success or positive error code on failure.
284 */
285 int
286 ti_prcm_clk_get_source_freq(clk_ident_t clk, unsigned int *freq)
287 {
288 struct ti_clock_dev *clk_dev;
289 int ret;
290
291 /* Find the clock within the devmap - it's a bit inefficent having a for
292 * loop for this, but this function should only called when a driver is
293 * being activated so IMHO not a big issue.
294 */
295 clk_dev = ti_prcm_clk_dev(clk);
296
297 /* Sanity check we managed to find the clock */
298 if (clk_dev == NULL)
299 return (EINVAL);
300
301 /* Get the source frequency of the clock */
302 if (clk_dev->clk_get_source_freq)
303 ret = clk_dev->clk_get_source_freq(clk_dev, freq);
304 else
305 ret = EINVAL;
306
307 return (ret);
308 }
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