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aecd8454 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
ab0ea257 LJ |
2 | /* |
3 | * Match running platform with pre-defined OPP values for CPUFreq | |
4 | * | |
5 | * Author: Ajit Pal Singh <ajitpal.singh@st.com> | |
6 | * Lee Jones <lee.jones@linaro.org> | |
7 | * | |
8 | * Copyright (C) 2015 STMicroelectronics (R&D) Limited | |
ab0ea257 LJ |
9 | */ |
10 | ||
11 | #include <linux/cpu.h> | |
12 | #include <linux/io.h> | |
13 | #include <linux/mfd/syscon.h> | |
14 | #include <linux/module.h> | |
15 | #include <linux/of.h> | |
16 | #include <linux/of_platform.h> | |
17 | #include <linux/pm_opp.h> | |
18 | #include <linux/regmap.h> | |
19 | ||
20 | #define VERSION_ELEMENTS 3 | |
21 | #define MAX_PCODE_NAME_LEN 7 | |
22 | ||
23 | #define VERSION_SHIFT 28 | |
24 | #define HW_INFO_INDEX 1 | |
25 | #define MAJOR_ID_INDEX 1 | |
26 | #define MINOR_ID_INDEX 2 | |
27 | ||
28 | /* | |
29 | * Only match on "suitable for ALL versions" entries | |
30 | * | |
31 | * This will be used with the BIT() macro. It sets the | |
32 | * top bit of a 32bit value and is equal to 0x80000000. | |
33 | */ | |
34 | #define DEFAULT_VERSION 31 | |
35 | ||
36 | enum { | |
37 | PCODE = 0, | |
38 | SUBSTRATE, | |
39 | DVFS_MAX_REGFIELDS, | |
40 | }; | |
41 | ||
42 | /** | |
34adbcbd | 43 | * struct sti_cpufreq_ddata - ST CPUFreq Driver Data |
ab0ea257 | 44 | * |
34adbcbd LJ |
45 | * @cpu: CPU's OF node |
46 | * @syscfg_eng: Engineering Syscon register map | |
47 | * @syscfg: Syscon register map | |
ab0ea257 LJ |
48 | */ |
49 | static struct sti_cpufreq_ddata { | |
50 | struct device *cpu; | |
51 | struct regmap *syscfg_eng; | |
52 | struct regmap *syscfg; | |
53 | } ddata; | |
54 | ||
55 | static int sti_cpufreq_fetch_major(void) { | |
56 | struct device_node *np = ddata.cpu->of_node; | |
57 | struct device *dev = ddata.cpu; | |
58 | unsigned int major_offset; | |
59 | unsigned int socid; | |
60 | int ret; | |
61 | ||
62 | ret = of_property_read_u32_index(np, "st,syscfg", | |
63 | MAJOR_ID_INDEX, &major_offset); | |
64 | if (ret) { | |
cc5a7a74 RH |
65 | dev_err(dev, "No major number offset provided in %pOF [%d]\n", |
66 | np, ret); | |
ab0ea257 LJ |
67 | return ret; |
68 | } | |
69 | ||
70 | ret = regmap_read(ddata.syscfg, major_offset, &socid); | |
71 | if (ret) { | |
72 | dev_err(dev, "Failed to read major number from syscon [%d]\n", | |
73 | ret); | |
74 | return ret; | |
75 | } | |
76 | ||
77 | return ((socid >> VERSION_SHIFT) & 0xf) + 1; | |
78 | } | |
79 | ||
80 | static int sti_cpufreq_fetch_minor(void) | |
81 | { | |
82 | struct device *dev = ddata.cpu; | |
83 | struct device_node *np = dev->of_node; | |
84 | unsigned int minor_offset; | |
85 | unsigned int minid; | |
86 | int ret; | |
87 | ||
88 | ret = of_property_read_u32_index(np, "st,syscfg-eng", | |
89 | MINOR_ID_INDEX, &minor_offset); | |
90 | if (ret) { | |
91 | dev_err(dev, | |
cc5a7a74 RH |
92 | "No minor number offset provided %pOF [%d]\n", |
93 | np, ret); | |
ab0ea257 LJ |
94 | return ret; |
95 | } | |
96 | ||
97 | ret = regmap_read(ddata.syscfg_eng, minor_offset, &minid); | |
98 | if (ret) { | |
99 | dev_err(dev, | |
100 | "Failed to read the minor number from syscon [%d]\n", | |
101 | ret); | |
102 | return ret; | |
103 | } | |
104 | ||
105 | return minid & 0xf; | |
106 | } | |
107 | ||
108 | static int sti_cpufreq_fetch_regmap_field(const struct reg_field *reg_fields, | |
109 | int hw_info_offset, int field) | |
110 | { | |
111 | struct regmap_field *regmap_field; | |
112 | struct reg_field reg_field = reg_fields[field]; | |
113 | struct device *dev = ddata.cpu; | |
114 | unsigned int value; | |
115 | int ret; | |
116 | ||
117 | reg_field.reg = hw_info_offset; | |
118 | regmap_field = devm_regmap_field_alloc(dev, | |
119 | ddata.syscfg_eng, | |
120 | reg_field); | |
121 | if (IS_ERR(regmap_field)) { | |
122 | dev_err(dev, "Failed to allocate reg field\n"); | |
123 | return PTR_ERR(regmap_field); | |
124 | } | |
125 | ||
126 | ret = regmap_field_read(regmap_field, &value); | |
127 | if (ret) { | |
128 | dev_err(dev, "Failed to read %s code\n", | |
129 | field ? "SUBSTRATE" : "PCODE"); | |
130 | return ret; | |
131 | } | |
132 | ||
133 | return value; | |
134 | } | |
135 | ||
136 | static const struct reg_field sti_stih407_dvfs_regfields[DVFS_MAX_REGFIELDS] = { | |
137 | [PCODE] = REG_FIELD(0, 16, 19), | |
138 | [SUBSTRATE] = REG_FIELD(0, 0, 2), | |
139 | }; | |
140 | ||
141 | static const struct reg_field *sti_cpufreq_match(void) | |
142 | { | |
143 | if (of_machine_is_compatible("st,stih407") || | |
01a163c5 AV |
144 | of_machine_is_compatible("st,stih410") || |
145 | of_machine_is_compatible("st,stih418")) | |
ab0ea257 LJ |
146 | return sti_stih407_dvfs_regfields; |
147 | ||
148 | return NULL; | |
149 | } | |
150 | ||
151 | static int sti_cpufreq_set_opp_info(void) | |
152 | { | |
153 | struct device *dev = ddata.cpu; | |
154 | struct device_node *np = dev->of_node; | |
155 | const struct reg_field *reg_fields; | |
156 | unsigned int hw_info_offset; | |
157 | unsigned int version[VERSION_ELEMENTS]; | |
158 | int pcode, substrate, major, minor; | |
159 | int ret; | |
160 | char name[MAX_PCODE_NAME_LEN]; | |
fa30184d | 161 | struct opp_table *opp_table; |
ab0ea257 LJ |
162 | |
163 | reg_fields = sti_cpufreq_match(); | |
164 | if (!reg_fields) { | |
9ad0a1b6 | 165 | dev_err(dev, "This SoC doesn't support voltage scaling\n"); |
ab0ea257 LJ |
166 | return -ENODEV; |
167 | } | |
168 | ||
169 | ret = of_property_read_u32_index(np, "st,syscfg-eng", | |
170 | HW_INFO_INDEX, &hw_info_offset); | |
171 | if (ret) { | |
172 | dev_warn(dev, "Failed to read HW info offset from DT\n"); | |
173 | substrate = DEFAULT_VERSION; | |
174 | pcode = 0; | |
175 | goto use_defaults; | |
176 | } | |
177 | ||
178 | pcode = sti_cpufreq_fetch_regmap_field(reg_fields, | |
179 | hw_info_offset, | |
180 | PCODE); | |
181 | if (pcode < 0) { | |
182 | dev_warn(dev, "Failed to obtain process code\n"); | |
183 | /* Use default pcode */ | |
184 | pcode = 0; | |
185 | } | |
186 | ||
187 | substrate = sti_cpufreq_fetch_regmap_field(reg_fields, | |
188 | hw_info_offset, | |
189 | SUBSTRATE); | |
190 | if (substrate) { | |
191 | dev_warn(dev, "Failed to obtain substrate code\n"); | |
192 | /* Use default substrate */ | |
193 | substrate = DEFAULT_VERSION; | |
194 | } | |
195 | ||
196 | use_defaults: | |
197 | major = sti_cpufreq_fetch_major(); | |
198 | if (major < 0) { | |
199 | dev_err(dev, "Failed to obtain major version\n"); | |
200 | /* Use default major number */ | |
201 | major = DEFAULT_VERSION; | |
202 | } | |
203 | ||
204 | minor = sti_cpufreq_fetch_minor(); | |
205 | if (minor < 0) { | |
206 | dev_err(dev, "Failed to obtain minor version\n"); | |
207 | /* Use default minor number */ | |
208 | minor = DEFAULT_VERSION; | |
209 | } | |
210 | ||
211 | snprintf(name, MAX_PCODE_NAME_LEN, "pcode%d", pcode); | |
212 | ||
fa30184d VK |
213 | opp_table = dev_pm_opp_set_prop_name(dev, name); |
214 | if (IS_ERR(opp_table)) { | |
ab0ea257 | 215 | dev_err(dev, "Failed to set prop name\n"); |
fa30184d | 216 | return PTR_ERR(opp_table); |
ab0ea257 LJ |
217 | } |
218 | ||
219 | version[0] = BIT(major); | |
220 | version[1] = BIT(minor); | |
221 | version[2] = BIT(substrate); | |
222 | ||
fa30184d VK |
223 | opp_table = dev_pm_opp_set_supported_hw(dev, version, VERSION_ELEMENTS); |
224 | if (IS_ERR(opp_table)) { | |
ab0ea257 | 225 | dev_err(dev, "Failed to set supported hardware\n"); |
3a5e6732 YL |
226 | ret = PTR_ERR(opp_table); |
227 | goto err_put_prop_name; | |
ab0ea257 LJ |
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; | |
3a5e6732 YL |
236 | |
237 | err_put_prop_name: | |
238 | dev_pm_opp_put_prop_name(opp_table); | |
239 | return ret; | |
ab0ea257 LJ |
240 | } |
241 | ||
ad61dd30 | 242 | static int sti_cpufreq_fetch_syscon_registers(void) |
ab0ea257 LJ |
243 | { |
244 | struct device *dev = ddata.cpu; | |
245 | struct device_node *np = dev->of_node; | |
246 | ||
247 | ddata.syscfg = syscon_regmap_lookup_by_phandle(np, "st,syscfg"); | |
248 | if (IS_ERR(ddata.syscfg)) { | |
249 | dev_err(dev, "\"st,syscfg\" not supplied\n"); | |
250 | return PTR_ERR(ddata.syscfg); | |
251 | } | |
252 | ||
253 | ddata.syscfg_eng = syscon_regmap_lookup_by_phandle(np, "st,syscfg-eng"); | |
254 | if (IS_ERR(ddata.syscfg_eng)) { | |
255 | dev_err(dev, "\"st,syscfg-eng\" not supplied\n"); | |
256 | return PTR_ERR(ddata.syscfg_eng); | |
257 | } | |
258 | ||
259 | return 0; | |
260 | } | |
261 | ||
262 | static int sti_cpufreq_init(void) | |
263 | { | |
264 | int ret; | |
265 | ||
2482bc31 | 266 | if ((!of_machine_is_compatible("st,stih407")) && |
01a163c5 AV |
267 | (!of_machine_is_compatible("st,stih410")) && |
268 | (!of_machine_is_compatible("st,stih418"))) | |
2482bc31 SH |
269 | return -ENODEV; |
270 | ||
ab0ea257 LJ |
271 | ddata.cpu = get_cpu_device(0); |
272 | if (!ddata.cpu) { | |
273 | dev_err(ddata.cpu, "Failed to get device for CPU0\n"); | |
274 | goto skip_voltage_scaling; | |
275 | } | |
276 | ||
277 | if (!of_get_property(ddata.cpu->of_node, "operating-points-v2", NULL)) { | |
278 | dev_err(ddata.cpu, "OPP-v2 not supported\n"); | |
279 | goto skip_voltage_scaling; | |
280 | } | |
281 | ||
ad61dd30 | 282 | ret = sti_cpufreq_fetch_syscon_registers(); |
ab0ea257 LJ |
283 | if (ret) |
284 | goto skip_voltage_scaling; | |
285 | ||
286 | ret = sti_cpufreq_set_opp_info(); | |
287 | if (!ret) | |
288 | goto register_cpufreq_dt; | |
289 | ||
290 | skip_voltage_scaling: | |
291 | dev_err(ddata.cpu, "Not doing voltage scaling\n"); | |
292 | ||
293 | register_cpufreq_dt: | |
294 | platform_device_register_simple("cpufreq-dt", -1, NULL, 0); | |
295 | ||
296 | return 0; | |
297 | } | |
298 | module_init(sti_cpufreq_init); | |
299 | ||
183747ab PR |
300 | static const struct of_device_id __maybe_unused sti_cpufreq_of_match[] = { |
301 | { .compatible = "st,stih407" }, | |
302 | { .compatible = "st,stih410" }, | |
303 | { }, | |
304 | }; | |
305 | MODULE_DEVICE_TABLE(of, sti_cpufreq_of_match); | |
306 | ||
ab0ea257 LJ |
307 | MODULE_DESCRIPTION("STMicroelectronics CPUFreq/OPP driver"); |
308 | MODULE_AUTHOR("Ajitpal Singh <ajitpal.singh@st.com>"); | |
309 | MODULE_AUTHOR("Lee Jones <lee.jones@linaro.org>"); | |
310 | MODULE_LICENSE("GPL v2"); |