2 * OMAP3/OMAP4 Voltage Management Routines
4 * Author: Thara Gopinath <thara@ti.com>
6 * Copyright (C) 2007 Texas Instruments, Inc.
7 * Rajendra Nayak <rnayak@ti.com>
8 * Lesly A M <x0080970@ti.com>
10 * Copyright (C) 2008, 2011 Nokia Corporation
14 * Copyright (C) 2010 Texas Instruments, Inc.
15 * Thara Gopinath <thara@ti.com>
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.
22 #include <linux/delay.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>
32 #include "prm-regbits-34xx.h"
33 #include "prm-regbits-44xx.h"
36 #include "prminst44xx.h"
40 #include "powerdomain.h"
45 static LIST_HEAD(voltdm_list);
47 /* Public functions */
49 * voltdm_get_voltage() - Gets the current non-auto-compensated voltage
50 * @voltdm: pointer to the voltdm for which current voltage info is needed
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.
55 unsigned long voltdm_get_voltage(struct voltagedomain *voltdm)
57 if (!voltdm || IS_ERR(voltdm)) {
58 pr_warn("%s: VDD specified does not exist!\n", __func__);
62 return voltdm->nominal_volt;
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
70 * This API should be called by the kernel to do the voltage scaling
71 * for a particular voltage domain during DVFS.
73 int voltdm_scale(struct voltagedomain *voltdm,
74 unsigned long target_volt)
77 unsigned long volt = 0;
79 if (!voltdm || IS_ERR(voltdm)) {
80 pr_warn("%s: VDD specified does not exist!\n", __func__);
85 pr_err("%s: No voltage scale API registered for vdd_%s\n",
86 __func__, voltdm->name);
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;
99 pr_warn("%s: not scaling. OPP voltage for %lu, not found.\n",
100 __func__, target_volt);
104 ret = voltdm->scale(voltdm, volt);
106 voltdm->nominal_volt = volt;
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.
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.
120 void voltdm_reset(struct voltagedomain *voltdm)
122 unsigned long target_volt;
124 if (!voltdm || IS_ERR(voltdm)) {
125 pr_warn("%s: VDD specified does not exist!\n", __func__);
129 target_volt = voltdm_get_voltage(voltdm);
131 pr_err("%s: unable to find current voltage for vdd_%s\n",
132 __func__, voltdm->name);
136 voltdm_scale(voltdm, target_volt);
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
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.
151 void omap_voltage_get_volttable(struct voltagedomain *voltdm,
152 struct omap_volt_data **volt_data)
154 if (!voltdm || IS_ERR(voltdm)) {
155 pr_warn("%s: VDD specified does not exist!\n", __func__);
159 *volt_data = voltdm->volt_data;
163 * omap_voltage_get_voltdata() - API to get the voltage table entry for a
165 * @voltdm: pointer to the VDD whose voltage table has to be searched
166 * @volt: the voltage to be searched in the voltage table
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
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.
177 struct omap_volt_data *omap_voltage_get_voltdata(struct voltagedomain *voltdm,
182 if (!voltdm || IS_ERR(voltdm)) {
183 pr_warn("%s: VDD specified does not exist!\n", __func__);
184 return ERR_PTR(-EINVAL);
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);
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];
198 pr_notice("%s: Unable to match the current voltage with the voltage table for vdd_%s\n",
199 __func__, voltdm->name);
201 return ERR_PTR(-ENODATA);
205 * omap_voltage_register_pmic() - API to register PMIC specific data
206 * @voltdm: pointer to the VDD for which the PMIC specific data is
208 * @pmic: the structure containing pmic info
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.
213 int omap_voltage_register_pmic(struct voltagedomain *voltdm,
214 struct omap_voltdm_pmic *pmic)
216 if (!voltdm || IS_ERR(voltdm)) {
217 pr_warn("%s: VDD specified does not exist!\n", __func__);
227 * omap_voltage_late_init() - Init the various voltage parameters
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.
233 int __init omap_voltage_late_init(void)
235 struct voltagedomain *voltdm;
237 if (list_empty(&voltdm_list)) {
238 pr_err("%s: Voltage driver support not added\n",
243 list_for_each_entry(voltdm, &voltdm_list, node) {
246 if (!voltdm->scalable)
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__);
254 voltdm->sys_clk.rate = clk_get_rate(sys_ck);
255 WARN_ON(!voltdm->sys_clk.rate);
259 voltdm->scale = omap_vc_bypass_scale;
260 omap_vc_init_channel(voltdm);
264 voltdm->scale = omap_vp_forceupdate_scale;
265 omap_vp_init(voltdm);
272 static struct voltagedomain *_voltdm_lookup(const char *name)
274 struct voltagedomain *voltdm, *temp_voltdm;
278 list_for_each_entry(temp_voltdm, &voltdm_list, node) {
279 if (!strcmp(name, temp_voltdm->name)) {
280 voltdm = temp_voltdm;
288 static int _voltdm_register(struct voltagedomain *voltdm)
290 if (!voltdm || !voltdm->name)
293 list_add(&voltdm->node, &voltdm_list);
295 pr_debug("voltagedomain: registered %s\n", voltdm->name);
301 * voltdm_lookup - look up a voltagedomain by name, return a pointer
302 * @name: name of voltagedomain
304 * Find a registered voltagedomain by its name @name. Returns a pointer
305 * to the struct voltagedomain if found, or NULL otherwise.
307 struct voltagedomain *voltdm_lookup(const char *name)
309 struct voltagedomain *voltdm ;
314 voltdm = _voltdm_lookup(name);
320 * voltdm_init - set up the voltagedomain layer
321 * @voltdm_list: array of struct voltagedomain pointers to register
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.
328 void voltdm_init(struct voltagedomain **voltdms)
330 struct voltagedomain **v;
333 for (v = voltdms; *v; v++)
334 _voltdm_register(*v);