• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 /*
2  * OMAP3/OMAP4 Voltage Management Routines
3  *
4  * Author: Thara Gopinath	<thara@ti.com>
5  *
6  * Copyright (C) 2007 Texas Instruments, Inc.
7  * Rajendra Nayak <rnayak@ti.com>
8  * Lesly A M <x0080970@ti.com>
9  *
10  * Copyright (C) 2008, 2011 Nokia Corporation
11  * Kalle Jokiniemi
12  * Paul Walmsley
13  *
14  * Copyright (C) 2010 Texas Instruments, Inc.
15  * Thara Gopinath <thara@ti.com>
16  *
17  * This program is free software; you can redistribute it and/or modify
18  * it under the terms of the GNU General Public License version 2 as
19  * published by the Free Software Foundation.
20  */
21 
22 #include <linux/delay.h>
23 #include <linux/io.h>
24 #include <linux/err.h>
25 #include <linux/export.h>
26 #include <linux/debugfs.h>
27 #include <linux/slab.h>
28 #include <linux/clk.h>
29 
30 #include "common.h"
31 
32 #include "prm-regbits-34xx.h"
33 #include "prm-regbits-44xx.h"
34 #include "prm44xx.h"
35 #include "prcm44xx.h"
36 #include "prminst44xx.h"
37 #include "control.h"
38 
39 #include "voltage.h"
40 #include "powerdomain.h"
41 
42 #include "vc.h"
43 #include "vp.h"
44 
45 static LIST_HEAD(voltdm_list);
46 
47 /* Public functions */
48 /**
49  * voltdm_get_voltage() - Gets the current non-auto-compensated voltage
50  * @voltdm:	pointer to the voltdm for which current voltage info is needed
51  *
52  * API to get the current non-auto-compensated voltage for a voltage domain.
53  * Returns 0 in case of error else returns the current voltage.
54  */
voltdm_get_voltage(struct voltagedomain * voltdm)55 unsigned long voltdm_get_voltage(struct voltagedomain *voltdm)
56 {
57 	if (!voltdm || IS_ERR(voltdm)) {
58 		pr_warn("%s: VDD specified does not exist!\n", __func__);
59 		return 0;
60 	}
61 
62 	return voltdm->nominal_volt;
63 }
64 
65 /**
66  * voltdm_scale() - API to scale voltage of a particular voltage domain.
67  * @voltdm: pointer to the voltage domain which is to be scaled.
68  * @target_volt: The target voltage of the voltage domain
69  *
70  * This API should be called by the kernel to do the voltage scaling
71  * for a particular voltage domain during DVFS.
72  */
voltdm_scale(struct voltagedomain * voltdm,unsigned long target_volt)73 int voltdm_scale(struct voltagedomain *voltdm,
74 		 unsigned long target_volt)
75 {
76 	int ret, i;
77 	unsigned long volt = 0;
78 
79 	if (!voltdm || IS_ERR(voltdm)) {
80 		pr_warn("%s: VDD specified does not exist!\n", __func__);
81 		return -EINVAL;
82 	}
83 
84 	if (!voltdm->scale) {
85 		pr_err("%s: No voltage scale API registered for vdd_%s\n",
86 			__func__, voltdm->name);
87 		return -ENODATA;
88 	}
89 
90 	/* Adjust voltage to the exact voltage from the OPP table */
91 	for (i = 0; voltdm->volt_data[i].volt_nominal != 0; i++) {
92 		if (voltdm->volt_data[i].volt_nominal >= target_volt) {
93 			volt = voltdm->volt_data[i].volt_nominal;
94 			break;
95 		}
96 	}
97 
98 	if (!volt) {
99 		pr_warn("%s: not scaling. OPP voltage for %lu, not found.\n",
100 			__func__, target_volt);
101 		return -EINVAL;
102 	}
103 
104 	ret = voltdm->scale(voltdm, volt);
105 	if (!ret)
106 		voltdm->nominal_volt = volt;
107 
108 	return ret;
109 }
110 
111 /**
112  * voltdm_reset() - Resets the voltage of a particular voltage domain
113  *		    to that of the current OPP.
114  * @voltdm: pointer to the voltage domain whose voltage is to be reset.
115  *
116  * This API finds out the correct voltage the voltage domain is supposed
117  * to be at and resets the voltage to that level. Should be used especially
118  * while disabling any voltage compensation modules.
119  */
voltdm_reset(struct voltagedomain * voltdm)120 void voltdm_reset(struct voltagedomain *voltdm)
121 {
122 	unsigned long target_volt;
123 
124 	if (!voltdm || IS_ERR(voltdm)) {
125 		pr_warn("%s: VDD specified does not exist!\n", __func__);
126 		return;
127 	}
128 
129 	target_volt = voltdm_get_voltage(voltdm);
130 	if (!target_volt) {
131 		pr_err("%s: unable to find current voltage for vdd_%s\n",
132 			__func__, voltdm->name);
133 		return;
134 	}
135 
136 	voltdm_scale(voltdm, target_volt);
137 }
138 
139 /**
140  * omap_voltage_get_volttable() - API to get the voltage table associated with a
141  *				particular voltage domain.
142  * @voltdm:	pointer to the VDD for which the voltage table is required
143  * @volt_data:	the voltage table for the particular vdd which is to be
144  *		populated by this API
145  *
146  * This API populates the voltage table associated with a VDD into the
147  * passed parameter pointer. Returns the count of distinct voltages
148  * supported by this vdd.
149  *
150  */
omap_voltage_get_volttable(struct voltagedomain * voltdm,struct omap_volt_data ** volt_data)151 void omap_voltage_get_volttable(struct voltagedomain *voltdm,
152 				struct omap_volt_data **volt_data)
153 {
154 	if (!voltdm || IS_ERR(voltdm)) {
155 		pr_warn("%s: VDD specified does not exist!\n", __func__);
156 		return;
157 	}
158 
159 	*volt_data = voltdm->volt_data;
160 }
161 
162 /**
163  * omap_voltage_get_voltdata() - API to get the voltage table entry for a
164  *				particular voltage
165  * @voltdm:	pointer to the VDD whose voltage table has to be searched
166  * @volt:	the voltage to be searched in the voltage table
167  *
168  * This API searches through the voltage table for the required voltage
169  * domain and tries to find a matching entry for the passed voltage volt.
170  * If a matching entry is found volt_data is populated with that entry.
171  * This API searches only through the non-compensated voltages int the
172  * voltage table.
173  * Returns pointer to the voltage table entry corresponding to volt on
174  * success. Returns -ENODATA if no voltage table exisits for the passed voltage
175  * domain or if there is no matching entry.
176  */
omap_voltage_get_voltdata(struct voltagedomain * voltdm,unsigned long volt)177 struct omap_volt_data *omap_voltage_get_voltdata(struct voltagedomain *voltdm,
178 						 unsigned long volt)
179 {
180 	int i;
181 
182 	if (!voltdm || IS_ERR(voltdm)) {
183 		pr_warn("%s: VDD specified does not exist!\n", __func__);
184 		return ERR_PTR(-EINVAL);
185 	}
186 
187 	if (!voltdm->volt_data) {
188 		pr_warn("%s: voltage table does not exist for vdd_%s\n",
189 			__func__, voltdm->name);
190 		return ERR_PTR(-ENODATA);
191 	}
192 
193 	for (i = 0; voltdm->volt_data[i].volt_nominal != 0; i++) {
194 		if (voltdm->volt_data[i].volt_nominal == volt)
195 			return &voltdm->volt_data[i];
196 	}
197 
198 	pr_notice("%s: Unable to match the current voltage with the voltage table for vdd_%s\n",
199 		  __func__, voltdm->name);
200 
201 	return ERR_PTR(-ENODATA);
202 }
203 
204 /**
205  * omap_voltage_register_pmic() - API to register PMIC specific data
206  * @voltdm:	pointer to the VDD for which the PMIC specific data is
207  *		to be registered
208  * @pmic:	the structure containing pmic info
209  *
210  * This API is to be called by the SOC/PMIC file to specify the
211  * pmic specific info as present in omap_voltdm_pmic structure.
212  */
omap_voltage_register_pmic(struct voltagedomain * voltdm,struct omap_voltdm_pmic * pmic)213 int omap_voltage_register_pmic(struct voltagedomain *voltdm,
214 			       struct omap_voltdm_pmic *pmic)
215 {
216 	if (!voltdm || IS_ERR(voltdm)) {
217 		pr_warn("%s: VDD specified does not exist!\n", __func__);
218 		return -EINVAL;
219 	}
220 
221 	voltdm->pmic = pmic;
222 
223 	return 0;
224 }
225 
226 /**
227  * omap_change_voltscale_method() - API to change the voltage scaling method.
228  * @voltdm:	pointer to the VDD whose voltage scaling method
229  *		has to be changed.
230  * @voltscale_method:	the method to be used for voltage scaling.
231  *
232  * This API can be used by the board files to change the method of voltage
233  * scaling between vpforceupdate and vcbypass. The parameter values are
234  * defined in voltage.h
235  */
omap_change_voltscale_method(struct voltagedomain * voltdm,int voltscale_method)236 void omap_change_voltscale_method(struct voltagedomain *voltdm,
237 				  int voltscale_method)
238 {
239 	if (!voltdm || IS_ERR(voltdm)) {
240 		pr_warn("%s: VDD specified does not exist!\n", __func__);
241 		return;
242 	}
243 
244 	switch (voltscale_method) {
245 	case VOLTSCALE_VPFORCEUPDATE:
246 		voltdm->scale = omap_vp_forceupdate_scale;
247 		return;
248 	case VOLTSCALE_VCBYPASS:
249 		voltdm->scale = omap_vc_bypass_scale;
250 		return;
251 	default:
252 		pr_warn("%s: Trying to change the method of voltage scaling to an unsupported one!\n",
253 			__func__);
254 	}
255 }
256 
257 /**
258  * omap_voltage_late_init() - Init the various voltage parameters
259  *
260  * This API is to be called in the later stages of the
261  * system boot to init the voltage controller and
262  * voltage processors.
263  */
omap_voltage_late_init(void)264 int __init omap_voltage_late_init(void)
265 {
266 	struct voltagedomain *voltdm;
267 
268 	if (list_empty(&voltdm_list)) {
269 		pr_err("%s: Voltage driver support not added\n",
270 			__func__);
271 		return -EINVAL;
272 	}
273 
274 	list_for_each_entry(voltdm, &voltdm_list, node) {
275 		struct clk *sys_ck;
276 
277 		if (!voltdm->scalable)
278 			continue;
279 
280 		sys_ck = clk_get(NULL, voltdm->sys_clk.name);
281 		if (IS_ERR(sys_ck)) {
282 			pr_warn("%s: Could not get sys clk.\n", __func__);
283 			return -EINVAL;
284 		}
285 		voltdm->sys_clk.rate = clk_get_rate(sys_ck);
286 		WARN_ON(!voltdm->sys_clk.rate);
287 		clk_put(sys_ck);
288 
289 		if (voltdm->vc) {
290 			voltdm->scale = omap_vc_bypass_scale;
291 			omap_vc_init_channel(voltdm);
292 		}
293 
294 		if (voltdm->vp) {
295 			voltdm->scale = omap_vp_forceupdate_scale;
296 			omap_vp_init(voltdm);
297 		}
298 	}
299 
300 	return 0;
301 }
302 
_voltdm_lookup(const char * name)303 static struct voltagedomain *_voltdm_lookup(const char *name)
304 {
305 	struct voltagedomain *voltdm, *temp_voltdm;
306 
307 	voltdm = NULL;
308 
309 	list_for_each_entry(temp_voltdm, &voltdm_list, node) {
310 		if (!strcmp(name, temp_voltdm->name)) {
311 			voltdm = temp_voltdm;
312 			break;
313 		}
314 	}
315 
316 	return voltdm;
317 }
318 
319 /**
320  * voltdm_add_pwrdm - add a powerdomain to a voltagedomain
321  * @voltdm: struct voltagedomain * to add the powerdomain to
322  * @pwrdm: struct powerdomain * to associate with a voltagedomain
323  *
324  * Associate the powerdomain @pwrdm with a voltagedomain @voltdm.  This
325  * enables the use of voltdm_for_each_pwrdm().  Returns -EINVAL if
326  * presented with invalid pointers; -ENOMEM if memory could not be allocated;
327  * or 0 upon success.
328  */
voltdm_add_pwrdm(struct voltagedomain * voltdm,struct powerdomain * pwrdm)329 int voltdm_add_pwrdm(struct voltagedomain *voltdm, struct powerdomain *pwrdm)
330 {
331 	if (!voltdm || !pwrdm)
332 		return -EINVAL;
333 
334 	pr_debug("voltagedomain: %s: associating powerdomain %s\n",
335 		 voltdm->name, pwrdm->name);
336 
337 	list_add(&pwrdm->voltdm_node, &voltdm->pwrdm_list);
338 
339 	return 0;
340 }
341 
342 /**
343  * voltdm_for_each_pwrdm - call function for each pwrdm in a voltdm
344  * @voltdm: struct voltagedomain * to iterate over
345  * @fn: callback function *
346  *
347  * Call the supplied function @fn for each powerdomain in the
348  * voltagedomain @voltdm.  Returns -EINVAL if presented with invalid
349  * pointers; or passes along the last return value of the callback
350  * function, which should be 0 for success or anything else to
351  * indicate failure.
352  */
voltdm_for_each_pwrdm(struct voltagedomain * voltdm,int (* fn)(struct voltagedomain * voltdm,struct powerdomain * pwrdm))353 int voltdm_for_each_pwrdm(struct voltagedomain *voltdm,
354 			  int (*fn)(struct voltagedomain *voltdm,
355 				    struct powerdomain *pwrdm))
356 {
357 	struct powerdomain *pwrdm;
358 	int ret = 0;
359 
360 	if (!fn)
361 		return -EINVAL;
362 
363 	list_for_each_entry(pwrdm, &voltdm->pwrdm_list, voltdm_node)
364 		ret = (*fn)(voltdm, pwrdm);
365 
366 	return ret;
367 }
368 
369 /**
370  * voltdm_for_each - call function on each registered voltagedomain
371  * @fn: callback function *
372  *
373  * Call the supplied function @fn for each registered voltagedomain.
374  * The callback function @fn can return anything but 0 to bail out
375  * early from the iterator.  Returns the last return value of the
376  * callback function, which should be 0 for success or anything else
377  * to indicate failure; or -EINVAL if the function pointer is null.
378  */
voltdm_for_each(int (* fn)(struct voltagedomain * voltdm,void * user),void * user)379 int voltdm_for_each(int (*fn)(struct voltagedomain *voltdm, void *user),
380 		    void *user)
381 {
382 	struct voltagedomain *temp_voltdm;
383 	int ret = 0;
384 
385 	if (!fn)
386 		return -EINVAL;
387 
388 	list_for_each_entry(temp_voltdm, &voltdm_list, node) {
389 		ret = (*fn)(temp_voltdm, user);
390 		if (ret)
391 			break;
392 	}
393 
394 	return ret;
395 }
396 
_voltdm_register(struct voltagedomain * voltdm)397 static int _voltdm_register(struct voltagedomain *voltdm)
398 {
399 	if (!voltdm || !voltdm->name)
400 		return -EINVAL;
401 
402 	INIT_LIST_HEAD(&voltdm->pwrdm_list);
403 	list_add(&voltdm->node, &voltdm_list);
404 
405 	pr_debug("voltagedomain: registered %s\n", voltdm->name);
406 
407 	return 0;
408 }
409 
410 /**
411  * voltdm_lookup - look up a voltagedomain by name, return a pointer
412  * @name: name of voltagedomain
413  *
414  * Find a registered voltagedomain by its name @name.  Returns a pointer
415  * to the struct voltagedomain if found, or NULL otherwise.
416  */
voltdm_lookup(const char * name)417 struct voltagedomain *voltdm_lookup(const char *name)
418 {
419 	struct voltagedomain *voltdm ;
420 
421 	if (!name)
422 		return NULL;
423 
424 	voltdm = _voltdm_lookup(name);
425 
426 	return voltdm;
427 }
428 
429 /**
430  * voltdm_init - set up the voltagedomain layer
431  * @voltdm_list: array of struct voltagedomain pointers to register
432  *
433  * Loop through the array of voltagedomains @voltdm_list, registering all
434  * that are available on the current CPU. If voltdm_list is supplied
435  * and not null, all of the referenced voltagedomains will be
436  * registered.  No return value.
437  */
voltdm_init(struct voltagedomain ** voltdms)438 void voltdm_init(struct voltagedomain **voltdms)
439 {
440 	struct voltagedomain **v;
441 
442 	if (voltdms) {
443 		for (v = voltdms; *v; v++)
444 			_voltdm_register(*v);
445 	}
446 }
447