1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * OMAP3/OMAP4 Voltage Management Routines
4 *
5 * Author: Thara Gopinath <thara@ti.com>
6 *
7 * Copyright (C) 2007 Texas Instruments, Inc.
8 * Rajendra Nayak <rnayak@ti.com>
9 * Lesly A M <x0080970@ti.com>
10 *
11 * Copyright (C) 2008, 2011 Nokia Corporation
12 * Kalle Jokiniemi
13 * Paul Walmsley
14 *
15 * Copyright (C) 2010 Texas Instruments, Inc.
16 * Thara Gopinath <thara@ti.com>
17 */
18
19#include <linux/delay.h>
20#include <linux/io.h>
21#include <linux/err.h>
22#include <linux/export.h>
23#include <linux/debugfs.h>
24#include <linux/slab.h>
25#include <linux/clk.h>
26
27#include "common.h"
28
29#include "prm-regbits-34xx.h"
30#include "prm-regbits-44xx.h"
31#include "prm44xx.h"
32#include "prcm44xx.h"
33#include "prminst44xx.h"
34#include "control.h"
35
36#include "voltage.h"
37#include "powerdomain.h"
38
39#include "vc.h"
40#include "vp.h"
41
42static LIST_HEAD(voltdm_list);
43
44/* Public functions */
45/**
46 * voltdm_get_voltage() - Gets the current non-auto-compensated voltage
47 * @voltdm: pointer to the voltdm for which current voltage info is needed
48 *
49 * API to get the current non-auto-compensated voltage for a voltage domain.
50 * Returns 0 in case of error else returns the current voltage.
51 */
52unsigned long voltdm_get_voltage(struct voltagedomain *voltdm)
53{
54 if (!voltdm || IS_ERR(ptr: voltdm)) {
55 pr_warn("%s: VDD specified does not exist!\n", __func__);
56 return 0;
57 }
58
59 return voltdm->nominal_volt;
60}
61
62/**
63 * voltdm_scale() - API to scale voltage of a particular voltage domain.
64 * @voltdm: pointer to the voltage domain which is to be scaled.
65 * @target_volt: The target voltage of the voltage domain
66 *
67 * This API should be called by the kernel to do the voltage scaling
68 * for a particular voltage domain during DVFS.
69 */
70static int voltdm_scale(struct voltagedomain *voltdm,
71 unsigned long target_volt)
72{
73 int ret, i;
74 unsigned long volt = 0;
75
76 if (!voltdm || IS_ERR(ptr: voltdm)) {
77 pr_warn("%s: VDD specified does not exist!\n", __func__);
78 return -EINVAL;
79 }
80
81 if (!voltdm->scale) {
82 pr_err("%s: No voltage scale API registered for vdd_%s\n",
83 __func__, voltdm->name);
84 return -ENODATA;
85 }
86
87 if (!voltdm->volt_data) {
88 pr_err("%s: No voltage data defined for vdd_%s\n",
89 __func__, voltdm->name);
90 return -ENODATA;
91 }
92
93 /* Adjust voltage to the exact voltage from the OPP table */
94 for (i = 0; voltdm->volt_data[i].volt_nominal != 0; i++) {
95 if (voltdm->volt_data[i].volt_nominal >= target_volt) {
96 volt = voltdm->volt_data[i].volt_nominal;
97 break;
98 }
99 }
100
101 if (!volt) {
102 pr_warn("%s: not scaling. OPP voltage for %lu, not found.\n",
103 __func__, target_volt);
104 return -EINVAL;
105 }
106
107 ret = voltdm->scale(voltdm, volt);
108 if (!ret)
109 voltdm->nominal_volt = volt;
110
111 return ret;
112}
113
114/**
115 * voltdm_reset() - Resets the voltage of a particular voltage domain
116 * to that of the current OPP.
117 * @voltdm: pointer to the voltage domain whose voltage is to be reset.
118 *
119 * This API finds out the correct voltage the voltage domain is supposed
120 * to be at and resets the voltage to that level. Should be used especially
121 * while disabling any voltage compensation modules.
122 */
123void voltdm_reset(struct voltagedomain *voltdm)
124{
125 unsigned long target_volt;
126
127 if (!voltdm || IS_ERR(ptr: voltdm)) {
128 pr_warn("%s: VDD specified does not exist!\n", __func__);
129 return;
130 }
131
132 target_volt = voltdm_get_voltage(voltdm);
133 if (!target_volt) {
134 pr_err("%s: unable to find current voltage for vdd_%s\n",
135 __func__, voltdm->name);
136 return;
137 }
138
139 voltdm_scale(voltdm, target_volt);
140}
141
142/**
143 * omap_voltage_get_volttable() - API to get the voltage table associated with a
144 * particular voltage domain.
145 * @voltdm: pointer to the VDD for which the voltage table is required
146 * @volt_data: the voltage table for the particular vdd which is to be
147 * populated by this API
148 *
149 * This API populates the voltage table associated with a VDD into the
150 * passed parameter pointer. Returns the count of distinct voltages
151 * supported by this vdd.
152 *
153 */
154void omap_voltage_get_volttable(struct voltagedomain *voltdm,
155 struct omap_volt_data **volt_data)
156{
157 if (!voltdm || IS_ERR(ptr: voltdm)) {
158 pr_warn("%s: VDD specified does not exist!\n", __func__);
159 return;
160 }
161
162 *volt_data = voltdm->volt_data;
163}
164
165/**
166 * omap_voltage_get_voltdata() - API to get the voltage table entry for a
167 * particular voltage
168 * @voltdm: pointer to the VDD whose voltage table has to be searched
169 * @volt: the voltage to be searched in the voltage table
170 *
171 * This API searches through the voltage table for the required voltage
172 * domain and tries to find a matching entry for the passed voltage volt.
173 * If a matching entry is found volt_data is populated with that entry.
174 * This API searches only through the non-compensated voltages int the
175 * voltage table.
176 * Returns pointer to the voltage table entry corresponding to volt on
177 * success. Returns -ENODATA if no voltage table exisits for the passed voltage
178 * domain or if there is no matching entry.
179 */
180struct omap_volt_data *omap_voltage_get_voltdata(struct voltagedomain *voltdm,
181 unsigned long volt)
182{
183 int i;
184
185 if (!voltdm || IS_ERR(ptr: voltdm)) {
186 pr_warn("%s: VDD specified does not exist!\n", __func__);
187 return ERR_PTR(error: -EINVAL);
188 }
189
190 if (!voltdm->volt_data) {
191 pr_warn("%s: voltage table does not exist for vdd_%s\n",
192 __func__, voltdm->name);
193 return ERR_PTR(error: -ENODATA);
194 }
195
196 for (i = 0; voltdm->volt_data[i].volt_nominal != 0; i++) {
197 if (voltdm->volt_data[i].volt_nominal == volt)
198 return &voltdm->volt_data[i];
199 }
200
201 pr_notice("%s: Unable to match the current voltage with the voltage table for vdd_%s\n",
202 __func__, voltdm->name);
203
204 return ERR_PTR(error: -ENODATA);
205}
206
207/**
208 * omap_voltage_register_pmic() - API to register PMIC specific data
209 * @voltdm: pointer to the VDD for which the PMIC specific data is
210 * to be registered
211 * @pmic: the structure containing pmic info
212 *
213 * This API is to be called by the SOC/PMIC file to specify the
214 * pmic specific info as present in omap_voltdm_pmic structure.
215 */
216int omap_voltage_register_pmic(struct voltagedomain *voltdm,
217 struct omap_voltdm_pmic *pmic)
218{
219 if (!voltdm || IS_ERR(ptr: voltdm)) {
220 pr_warn("%s: VDD specified does not exist!\n", __func__);
221 return -EINVAL;
222 }
223
224 voltdm->pmic = pmic;
225
226 return 0;
227}
228
229/**
230 * omap_voltage_late_init() - Init the various voltage parameters
231 *
232 * This API is to be called in the later stages of the
233 * system boot to init the voltage controller and
234 * voltage processors.
235 */
236int __init omap_voltage_late_init(void)
237{
238 struct voltagedomain *voltdm;
239
240 if (list_empty(head: &voltdm_list)) {
241 pr_err("%s: Voltage driver support not added\n",
242 __func__);
243 return -EINVAL;
244 }
245
246 list_for_each_entry(voltdm, &voltdm_list, node) {
247 struct clk *sys_ck;
248
249 if (!voltdm->scalable)
250 continue;
251
252 sys_ck = clk_get(NULL, id: voltdm->sys_clk.name);
253 if (IS_ERR(ptr: sys_ck)) {
254 pr_warn("%s: Could not get sys clk.\n", __func__);
255 return -EINVAL;
256 }
257 voltdm->sys_clk.rate = clk_get_rate(clk: sys_ck);
258 WARN_ON(!voltdm->sys_clk.rate);
259 clk_put(clk: sys_ck);
260
261 if (voltdm->vc) {
262 voltdm->scale = omap_vc_bypass_scale;
263 omap_vc_init_channel(voltdm);
264 }
265
266 if (voltdm->vp) {
267 voltdm->scale = omap_vp_forceupdate_scale;
268 omap_vp_init(voltdm);
269 }
270 }
271
272 return 0;
273}
274
275static struct voltagedomain *_voltdm_lookup(const char *name)
276{
277 struct voltagedomain *voltdm, *temp_voltdm;
278
279 voltdm = NULL;
280
281 list_for_each_entry(temp_voltdm, &voltdm_list, node) {
282 if (!strcmp(name, temp_voltdm->name)) {
283 voltdm = temp_voltdm;
284 break;
285 }
286 }
287
288 return voltdm;
289}
290
291static int _voltdm_register(struct voltagedomain *voltdm)
292{
293 if (!voltdm || !voltdm->name)
294 return -EINVAL;
295
296 list_add(new: &voltdm->node, head: &voltdm_list);
297
298 pr_debug("voltagedomain: registered %s\n", voltdm->name);
299
300 return 0;
301}
302
303/**
304 * voltdm_lookup - look up a voltagedomain by name, return a pointer
305 * @name: name of voltagedomain
306 *
307 * Find a registered voltagedomain by its name @name. Returns a pointer
308 * to the struct voltagedomain if found, or NULL otherwise.
309 */
310struct voltagedomain *voltdm_lookup(const char *name)
311{
312 struct voltagedomain *voltdm ;
313
314 if (!name)
315 return NULL;
316
317 voltdm = _voltdm_lookup(name);
318
319 return voltdm;
320}
321
322/**
323 * voltdm_init - set up the voltagedomain layer
324 * @voltdm_list: array of struct voltagedomain pointers to register
325 *
326 * Loop through the array of voltagedomains @voltdm_list, registering all
327 * that are available on the current CPU. If voltdm_list is supplied
328 * and not null, all of the referenced voltagedomains will be
329 * registered. No return value.
330 */
331void voltdm_init(struct voltagedomain **voltdms)
332{
333 struct voltagedomain **v;
334
335 if (voltdms) {
336 for (v = voltdms; *v; v++)
337 _voltdm_register(voltdm: *v);
338 }
339}
340

source code of linux/arch/arm/mach-omap2/voltage.c