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
42 static 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 */
52 unsigned long voltdm_get_voltage(struct voltagedomain *voltdm)
53 {
54 if (!voltdm || IS_ERR(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 */
70 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(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 */
123 void voltdm_reset(struct voltagedomain *voltdm)
124 {
125 unsigned long target_volt;
126
127 if (!voltdm || IS_ERR(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 */
154 void omap_voltage_get_volttable(struct voltagedomain *voltdm,
155 struct omap_volt_data **volt_data)
156 {
157 if (!voltdm || IS_ERR(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 */
180 struct omap_volt_data *omap_voltage_get_voltdata(struct voltagedomain *voltdm,
181 unsigned long volt)
182 {
183 int i;
184
185 if (!voltdm || IS_ERR(voltdm)) {
186 pr_warn("%s: VDD specified does not exist!\n", __func__);
187 return ERR_PTR(-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(-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(-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 */
216 int omap_voltage_register_pmic(struct voltagedomain *voltdm,
217 struct omap_voltdm_pmic *pmic)
218 {
219 if (!voltdm || IS_ERR(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 */
236 int __init omap_voltage_late_init(void)
237 {
238 struct voltagedomain *voltdm;
239
240 if (list_empty(&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, voltdm->sys_clk.name);
253 if (IS_ERR(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(sys_ck);
258 WARN_ON(!voltdm->sys_clk.rate);
259 clk_put(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
275 static 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
291 static int _voltdm_register(struct voltagedomain *voltdm)
292 {
293 if (!voltdm || !voltdm->name)
294 return -EINVAL;
295
296 list_add(&voltdm->node, &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 */
310 struct 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 */
331 void voltdm_init(struct voltagedomain **voltdms)
332 {
333 struct voltagedomain **v;
334
335 if (voltdms) {
336 for (v = voltdms; *v; v++)
337 _voltdm_register(*v);
338 }
339 }