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_voltage_late_init() - Init the various voltage parameters
228 *
229 * This API is to be called in the later stages of the
230 * system boot to init the voltage controller and
231 * voltage processors.
232 */
omap_voltage_late_init(void)233 int __init omap_voltage_late_init(void)
234 {
235 struct voltagedomain *voltdm;
236
237 if (list_empty(&voltdm_list)) {
238 pr_err("%s: Voltage driver support not added\n",
239 __func__);
240 return -EINVAL;
241 }
242
243 list_for_each_entry(voltdm, &voltdm_list, node) {
244 struct clk *sys_ck;
245
246 if (!voltdm->scalable)
247 continue;
248
249 sys_ck = clk_get(NULL, voltdm->sys_clk.name);
250 if (IS_ERR(sys_ck)) {
251 pr_warn("%s: Could not get sys clk.\n", __func__);
252 return -EINVAL;
253 }
254 voltdm->sys_clk.rate = clk_get_rate(sys_ck);
255 WARN_ON(!voltdm->sys_clk.rate);
256 clk_put(sys_ck);
257
258 if (voltdm->vc) {
259 voltdm->scale = omap_vc_bypass_scale;
260 omap_vc_init_channel(voltdm);
261 }
262
263 if (voltdm->vp) {
264 voltdm->scale = omap_vp_forceupdate_scale;
265 omap_vp_init(voltdm);
266 }
267 }
268
269 return 0;
270 }
271
_voltdm_lookup(const char * name)272 static struct voltagedomain *_voltdm_lookup(const char *name)
273 {
274 struct voltagedomain *voltdm, *temp_voltdm;
275
276 voltdm = NULL;
277
278 list_for_each_entry(temp_voltdm, &voltdm_list, node) {
279 if (!strcmp(name, temp_voltdm->name)) {
280 voltdm = temp_voltdm;
281 break;
282 }
283 }
284
285 return voltdm;
286 }
287
_voltdm_register(struct voltagedomain * voltdm)288 static int _voltdm_register(struct voltagedomain *voltdm)
289 {
290 if (!voltdm || !voltdm->name)
291 return -EINVAL;
292
293 list_add(&voltdm->node, &voltdm_list);
294
295 pr_debug("voltagedomain: registered %s\n", voltdm->name);
296
297 return 0;
298 }
299
300 /**
301 * voltdm_lookup - look up a voltagedomain by name, return a pointer
302 * @name: name of voltagedomain
303 *
304 * Find a registered voltagedomain by its name @name. Returns a pointer
305 * to the struct voltagedomain if found, or NULL otherwise.
306 */
voltdm_lookup(const char * name)307 struct voltagedomain *voltdm_lookup(const char *name)
308 {
309 struct voltagedomain *voltdm ;
310
311 if (!name)
312 return NULL;
313
314 voltdm = _voltdm_lookup(name);
315
316 return voltdm;
317 }
318
319 /**
320 * voltdm_init - set up the voltagedomain layer
321 * @voltdm_list: array of struct voltagedomain pointers to register
322 *
323 * Loop through the array of voltagedomains @voltdm_list, registering all
324 * that are available on the current CPU. If voltdm_list is supplied
325 * and not null, all of the referenced voltagedomains will be
326 * registered. No return value.
327 */
voltdm_init(struct voltagedomain ** voltdms)328 void voltdm_init(struct voltagedomain **voltdms)
329 {
330 struct voltagedomain **v;
331
332 if (voltdms) {
333 for (v = voltdms; *v; v++)
334 _voltdm_register(*v);
335 }
336 }
337