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ab0ea257 LJ |
1 | /* |
2 | * Match running platform with pre-defined OPP values for CPUFreq | |
3 | * | |
4 | * Author: Ajit Pal Singh <ajitpal.singh@st.com> | |
5 | * Lee Jones <lee.jones@linaro.org> | |
6 | * | |
7 | * Copyright (C) 2015 STMicroelectronics (R&D) Limited | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or modify | |
10 | * it under the terms of the version 2 of the GNU General Public License as | |
11 | * published by the Free Software Foundation | |
12 | */ | |
13 | ||
14 | #include <linux/cpu.h> | |
15 | #include <linux/io.h> | |
16 | #include <linux/mfd/syscon.h> | |
17 | #include <linux/module.h> | |
18 | #include <linux/of.h> | |
19 | #include <linux/of_platform.h> | |
20 | #include <linux/pm_opp.h> | |
21 | #include <linux/regmap.h> | |
22 | ||
23 | #define VERSION_ELEMENTS 3 | |
24 | #define MAX_PCODE_NAME_LEN 7 | |
25 | ||
26 | #define VERSION_SHIFT 28 | |
27 | #define HW_INFO_INDEX 1 | |
28 | #define MAJOR_ID_INDEX 1 | |
29 | #define MINOR_ID_INDEX 2 | |
30 | ||
31 | /* | |
32 | * Only match on "suitable for ALL versions" entries | |
33 | * | |
34 | * This will be used with the BIT() macro. It sets the | |
35 | * top bit of a 32bit value and is equal to 0x80000000. | |
36 | */ | |
37 | #define DEFAULT_VERSION 31 | |
38 | ||
39 | enum { | |
40 | PCODE = 0, | |
41 | SUBSTRATE, | |
42 | DVFS_MAX_REGFIELDS, | |
43 | }; | |
44 | ||
45 | /** | |
46 | * ST CPUFreq Driver Data | |
47 | * | |
48 | * @cpu_node CPU's OF node | |
49 | * @syscfg_eng Engineering Syscon register map | |
50 | * @regmap Syscon register map | |
51 | */ | |
52 | static struct sti_cpufreq_ddata { | |
53 | struct device *cpu; | |
54 | struct regmap *syscfg_eng; | |
55 | struct regmap *syscfg; | |
56 | } ddata; | |
57 | ||
58 | static int sti_cpufreq_fetch_major(void) { | |
59 | struct device_node *np = ddata.cpu->of_node; | |
60 | struct device *dev = ddata.cpu; | |
61 | unsigned int major_offset; | |
62 | unsigned int socid; | |
63 | int ret; | |
64 | ||
65 | ret = of_property_read_u32_index(np, "st,syscfg", | |
66 | MAJOR_ID_INDEX, &major_offset); | |
67 | if (ret) { | |
68 | dev_err(dev, "No major number offset provided in %s [%d]\n", | |
69 | np->full_name, ret); | |
70 | return ret; | |
71 | } | |
72 | ||
73 | ret = regmap_read(ddata.syscfg, major_offset, &socid); | |
74 | if (ret) { | |
75 | dev_err(dev, "Failed to read major number from syscon [%d]\n", | |
76 | ret); | |
77 | return ret; | |
78 | } | |
79 | ||
80 | return ((socid >> VERSION_SHIFT) & 0xf) + 1; | |
81 | } | |
82 | ||
83 | static int sti_cpufreq_fetch_minor(void) | |
84 | { | |
85 | struct device *dev = ddata.cpu; | |
86 | struct device_node *np = dev->of_node; | |
87 | unsigned int minor_offset; | |
88 | unsigned int minid; | |
89 | int ret; | |
90 | ||
91 | ret = of_property_read_u32_index(np, "st,syscfg-eng", | |
92 | MINOR_ID_INDEX, &minor_offset); | |
93 | if (ret) { | |
94 | dev_err(dev, | |
95 | "No minor number offset provided %s [%d]\n", | |
96 | np->full_name, ret); | |
97 | return ret; | |
98 | } | |
99 | ||
100 | ret = regmap_read(ddata.syscfg_eng, minor_offset, &minid); | |
101 | if (ret) { | |
102 | dev_err(dev, | |
103 | "Failed to read the minor number from syscon [%d]\n", | |
104 | ret); | |
105 | return ret; | |
106 | } | |
107 | ||
108 | return minid & 0xf; | |
109 | } | |
110 | ||
111 | static int sti_cpufreq_fetch_regmap_field(const struct reg_field *reg_fields, | |
112 | int hw_info_offset, int field) | |
113 | { | |
114 | struct regmap_field *regmap_field; | |
115 | struct reg_field reg_field = reg_fields[field]; | |
116 | struct device *dev = ddata.cpu; | |
117 | unsigned int value; | |
118 | int ret; | |
119 | ||
120 | reg_field.reg = hw_info_offset; | |
121 | regmap_field = devm_regmap_field_alloc(dev, | |
122 | ddata.syscfg_eng, | |
123 | reg_field); | |
124 | if (IS_ERR(regmap_field)) { | |
125 | dev_err(dev, "Failed to allocate reg field\n"); | |
126 | return PTR_ERR(regmap_field); | |
127 | } | |
128 | ||
129 | ret = regmap_field_read(regmap_field, &value); | |
130 | if (ret) { | |
131 | dev_err(dev, "Failed to read %s code\n", | |
132 | field ? "SUBSTRATE" : "PCODE"); | |
133 | return ret; | |
134 | } | |
135 | ||
136 | return value; | |
137 | } | |
138 | ||
139 | static const struct reg_field sti_stih407_dvfs_regfields[DVFS_MAX_REGFIELDS] = { | |
140 | [PCODE] = REG_FIELD(0, 16, 19), | |
141 | [SUBSTRATE] = REG_FIELD(0, 0, 2), | |
142 | }; | |
143 | ||
144 | static const struct reg_field *sti_cpufreq_match(void) | |
145 | { | |
146 | if (of_machine_is_compatible("st,stih407") || | |
147 | of_machine_is_compatible("st,stih410")) | |
148 | return sti_stih407_dvfs_regfields; | |
149 | ||
150 | return NULL; | |
151 | } | |
152 | ||
153 | static int sti_cpufreq_set_opp_info(void) | |
154 | { | |
155 | struct device *dev = ddata.cpu; | |
156 | struct device_node *np = dev->of_node; | |
157 | const struct reg_field *reg_fields; | |
158 | unsigned int hw_info_offset; | |
159 | unsigned int version[VERSION_ELEMENTS]; | |
160 | int pcode, substrate, major, minor; | |
161 | int ret; | |
162 | char name[MAX_PCODE_NAME_LEN]; | |
163 | ||
164 | reg_fields = sti_cpufreq_match(); | |
165 | if (!reg_fields) { | |
166 | dev_err(dev, "This SoC doesn't support voltage scaling"); | |
167 | return -ENODEV; | |
168 | } | |
169 | ||
170 | ret = of_property_read_u32_index(np, "st,syscfg-eng", | |
171 | HW_INFO_INDEX, &hw_info_offset); | |
172 | if (ret) { | |
173 | dev_warn(dev, "Failed to read HW info offset from DT\n"); | |
174 | substrate = DEFAULT_VERSION; | |
175 | pcode = 0; | |
176 | goto use_defaults; | |
177 | } | |
178 | ||
179 | pcode = sti_cpufreq_fetch_regmap_field(reg_fields, | |
180 | hw_info_offset, | |
181 | PCODE); | |
182 | if (pcode < 0) { | |
183 | dev_warn(dev, "Failed to obtain process code\n"); | |
184 | /* Use default pcode */ | |
185 | pcode = 0; | |
186 | } | |
187 | ||
188 | substrate = sti_cpufreq_fetch_regmap_field(reg_fields, | |
189 | hw_info_offset, | |
190 | SUBSTRATE); | |
191 | if (substrate) { | |
192 | dev_warn(dev, "Failed to obtain substrate code\n"); | |
193 | /* Use default substrate */ | |
194 | substrate = DEFAULT_VERSION; | |
195 | } | |
196 | ||
197 | use_defaults: | |
198 | major = sti_cpufreq_fetch_major(); | |
199 | if (major < 0) { | |
200 | dev_err(dev, "Failed to obtain major version\n"); | |
201 | /* Use default major number */ | |
202 | major = DEFAULT_VERSION; | |
203 | } | |
204 | ||
205 | minor = sti_cpufreq_fetch_minor(); | |
206 | if (minor < 0) { | |
207 | dev_err(dev, "Failed to obtain minor version\n"); | |
208 | /* Use default minor number */ | |
209 | minor = DEFAULT_VERSION; | |
210 | } | |
211 | ||
212 | snprintf(name, MAX_PCODE_NAME_LEN, "pcode%d", pcode); | |
213 | ||
214 | ret = dev_pm_opp_set_prop_name(dev, name); | |
215 | if (ret) { | |
216 | dev_err(dev, "Failed to set prop name\n"); | |
217 | return ret; | |
218 | } | |
219 | ||
220 | version[0] = BIT(major); | |
221 | version[1] = BIT(minor); | |
222 | version[2] = BIT(substrate); | |
223 | ||
224 | ret = dev_pm_opp_set_supported_hw(dev, version, VERSION_ELEMENTS); | |
225 | if (ret) { | |
226 | dev_err(dev, "Failed to set supported hardware\n"); | |
227 | return ret; | |
228 | } | |
229 | ||
230 | dev_dbg(dev, "pcode: %d major: %d minor: %d substrate: %d\n", | |
231 | pcode, major, minor, substrate); | |
232 | dev_dbg(dev, "version[0]: %x version[1]: %x version[2]: %x\n", | |
233 | version[0], version[1], version[2]); | |
234 | ||
235 | return 0; | |
236 | } | |
237 | ||
238 | static int sti_cpufreq_fetch_syscon_regsiters(void) | |
239 | { | |
240 | struct device *dev = ddata.cpu; | |
241 | struct device_node *np = dev->of_node; | |
242 | ||
243 | ddata.syscfg = syscon_regmap_lookup_by_phandle(np, "st,syscfg"); | |
244 | if (IS_ERR(ddata.syscfg)) { | |
245 | dev_err(dev, "\"st,syscfg\" not supplied\n"); | |
246 | return PTR_ERR(ddata.syscfg); | |
247 | } | |
248 | ||
249 | ddata.syscfg_eng = syscon_regmap_lookup_by_phandle(np, "st,syscfg-eng"); | |
250 | if (IS_ERR(ddata.syscfg_eng)) { | |
251 | dev_err(dev, "\"st,syscfg-eng\" not supplied\n"); | |
252 | return PTR_ERR(ddata.syscfg_eng); | |
253 | } | |
254 | ||
255 | return 0; | |
256 | } | |
257 | ||
258 | static int sti_cpufreq_init(void) | |
259 | { | |
260 | int ret; | |
261 | ||
2482bc31 SH |
262 | if ((!of_machine_is_compatible("st,stih407")) && |
263 | (!of_machine_is_compatible("st,stih410"))) | |
264 | return -ENODEV; | |
265 | ||
ab0ea257 LJ |
266 | ddata.cpu = get_cpu_device(0); |
267 | if (!ddata.cpu) { | |
268 | dev_err(ddata.cpu, "Failed to get device for CPU0\n"); | |
269 | goto skip_voltage_scaling; | |
270 | } | |
271 | ||
272 | if (!of_get_property(ddata.cpu->of_node, "operating-points-v2", NULL)) { | |
273 | dev_err(ddata.cpu, "OPP-v2 not supported\n"); | |
274 | goto skip_voltage_scaling; | |
275 | } | |
276 | ||
277 | ret = sti_cpufreq_fetch_syscon_regsiters(); | |
278 | if (ret) | |
279 | goto skip_voltage_scaling; | |
280 | ||
281 | ret = sti_cpufreq_set_opp_info(); | |
282 | if (!ret) | |
283 | goto register_cpufreq_dt; | |
284 | ||
285 | skip_voltage_scaling: | |
286 | dev_err(ddata.cpu, "Not doing voltage scaling\n"); | |
287 | ||
288 | register_cpufreq_dt: | |
289 | platform_device_register_simple("cpufreq-dt", -1, NULL, 0); | |
290 | ||
291 | return 0; | |
292 | } | |
293 | module_init(sti_cpufreq_init); | |
294 | ||
295 | MODULE_DESCRIPTION("STMicroelectronics CPUFreq/OPP driver"); | |
296 | MODULE_AUTHOR("Ajitpal Singh <ajitpal.singh@st.com>"); | |
297 | MODULE_AUTHOR("Lee Jones <lee.jones@linaro.org>"); | |
298 | MODULE_LICENSE("GPL v2"); |