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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