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1 | /* |
2 | * TI CPUFreq/OPP hw-supported driver | |
3 | * | |
4 | * Copyright (C) 2016-2017 Texas Instruments, Inc. | |
5 | * Dave Gerlach <d-gerlach@ti.com> | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or | |
8 | * modify it under the terms of the GNU General Public License | |
9 | * version 2 as published by the Free Software Foundation. | |
10 | * | |
11 | * This program is distributed in the hope that it will be useful, | |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | * GNU General Public License for more details. | |
15 | */ | |
16 | ||
17 | #include <linux/cpu.h> | |
18 | #include <linux/io.h> | |
19 | #include <linux/mfd/syscon.h> | |
20 | #include <linux/module.h> | |
21 | #include <linux/of.h> | |
22 | #include <linux/of_platform.h> | |
23 | #include <linux/pm_opp.h> | |
24 | #include <linux/regmap.h> | |
25 | #include <linux/slab.h> | |
26 | ||
27 | #define REVISION_MASK 0xF | |
28 | #define REVISION_SHIFT 28 | |
29 | ||
30 | #define AM33XX_800M_ARM_MPU_MAX_FREQ 0x1E2F | |
31 | #define AM43XX_600M_ARM_MPU_MAX_FREQ 0xFFA | |
32 | ||
33 | #define DRA7_EFUSE_HAS_OD_MPU_OPP 11 | |
34 | #define DRA7_EFUSE_HAS_HIGH_MPU_OPP 15 | |
35 | #define DRA7_EFUSE_HAS_ALL_MPU_OPP 23 | |
36 | ||
37 | #define DRA7_EFUSE_NOM_MPU_OPP BIT(0) | |
38 | #define DRA7_EFUSE_OD_MPU_OPP BIT(1) | |
39 | #define DRA7_EFUSE_HIGH_MPU_OPP BIT(2) | |
40 | ||
41 | #define VERSION_COUNT 2 | |
42 | ||
43 | struct ti_cpufreq_data; | |
44 | ||
45 | struct ti_cpufreq_soc_data { | |
46 | unsigned long (*efuse_xlate)(struct ti_cpufreq_data *opp_data, | |
47 | unsigned long efuse); | |
48 | unsigned long efuse_fallback; | |
49 | unsigned long efuse_offset; | |
50 | unsigned long efuse_mask; | |
51 | unsigned long efuse_shift; | |
52 | unsigned long rev_offset; | |
53 | }; | |
54 | ||
55 | struct ti_cpufreq_data { | |
56 | struct device *cpu_dev; | |
57 | struct device_node *opp_node; | |
58 | struct regmap *syscon; | |
59 | const struct ti_cpufreq_soc_data *soc_data; | |
60 | }; | |
61 | ||
62 | static unsigned long amx3_efuse_xlate(struct ti_cpufreq_data *opp_data, | |
63 | unsigned long efuse) | |
64 | { | |
65 | if (!efuse) | |
66 | efuse = opp_data->soc_data->efuse_fallback; | |
67 | /* AM335x and AM437x use "OPP disable" bits, so invert */ | |
68 | return ~efuse; | |
69 | } | |
70 | ||
71 | static unsigned long dra7_efuse_xlate(struct ti_cpufreq_data *opp_data, | |
72 | unsigned long efuse) | |
73 | { | |
74 | unsigned long calculated_efuse = DRA7_EFUSE_NOM_MPU_OPP; | |
75 | ||
76 | /* | |
77 | * The efuse on dra7 and am57 parts contains a specific | |
78 | * value indicating the highest available OPP. | |
79 | */ | |
80 | ||
81 | switch (efuse) { | |
82 | case DRA7_EFUSE_HAS_ALL_MPU_OPP: | |
83 | case DRA7_EFUSE_HAS_HIGH_MPU_OPP: | |
84 | calculated_efuse |= DRA7_EFUSE_HIGH_MPU_OPP; | |
85 | case DRA7_EFUSE_HAS_OD_MPU_OPP: | |
86 | calculated_efuse |= DRA7_EFUSE_OD_MPU_OPP; | |
87 | } | |
88 | ||
89 | return calculated_efuse; | |
90 | } | |
91 | ||
92 | static struct ti_cpufreq_soc_data am3x_soc_data = { | |
93 | .efuse_xlate = amx3_efuse_xlate, | |
94 | .efuse_fallback = AM33XX_800M_ARM_MPU_MAX_FREQ, | |
95 | .efuse_offset = 0x07fc, | |
96 | .efuse_mask = 0x1fff, | |
97 | .rev_offset = 0x600, | |
98 | }; | |
99 | ||
100 | static struct ti_cpufreq_soc_data am4x_soc_data = { | |
101 | .efuse_xlate = amx3_efuse_xlate, | |
102 | .efuse_fallback = AM43XX_600M_ARM_MPU_MAX_FREQ, | |
103 | .efuse_offset = 0x0610, | |
104 | .efuse_mask = 0x3f, | |
105 | .rev_offset = 0x600, | |
106 | }; | |
107 | ||
108 | static struct ti_cpufreq_soc_data dra7_soc_data = { | |
109 | .efuse_xlate = dra7_efuse_xlate, | |
110 | .efuse_offset = 0x020c, | |
111 | .efuse_mask = 0xf80000, | |
112 | .efuse_shift = 19, | |
113 | .rev_offset = 0x204, | |
114 | }; | |
115 | ||
116 | /** | |
117 | * ti_cpufreq_get_efuse() - Parse and return efuse value present on SoC | |
118 | * @opp_data: pointer to ti_cpufreq_data context | |
119 | * @efuse_value: Set to the value parsed from efuse | |
120 | * | |
121 | * Returns error code if efuse not read properly. | |
122 | */ | |
123 | static int ti_cpufreq_get_efuse(struct ti_cpufreq_data *opp_data, | |
124 | u32 *efuse_value) | |
125 | { | |
126 | struct device *dev = opp_data->cpu_dev; | |
127 | u32 efuse; | |
128 | int ret; | |
129 | ||
130 | ret = regmap_read(opp_data->syscon, opp_data->soc_data->efuse_offset, | |
131 | &efuse); | |
132 | if (ret) { | |
133 | dev_err(dev, | |
134 | "Failed to read the efuse value from syscon: %d\n", | |
135 | ret); | |
136 | return ret; | |
137 | } | |
138 | ||
139 | efuse = (efuse & opp_data->soc_data->efuse_mask); | |
140 | efuse >>= opp_data->soc_data->efuse_shift; | |
141 | ||
142 | *efuse_value = opp_data->soc_data->efuse_xlate(opp_data, efuse); | |
143 | ||
144 | return 0; | |
145 | } | |
146 | ||
147 | /** | |
148 | * ti_cpufreq_get_rev() - Parse and return rev value present on SoC | |
149 | * @opp_data: pointer to ti_cpufreq_data context | |
150 | * @revision_value: Set to the value parsed from revision register | |
151 | * | |
152 | * Returns error code if revision not read properly. | |
153 | */ | |
154 | static int ti_cpufreq_get_rev(struct ti_cpufreq_data *opp_data, | |
155 | u32 *revision_value) | |
156 | { | |
157 | struct device *dev = opp_data->cpu_dev; | |
158 | u32 revision; | |
159 | int ret; | |
160 | ||
161 | ret = regmap_read(opp_data->syscon, opp_data->soc_data->rev_offset, | |
162 | &revision); | |
163 | if (ret) { | |
164 | dev_err(dev, | |
165 | "Failed to read the revision number from syscon: %d\n", | |
166 | ret); | |
167 | return ret; | |
168 | } | |
169 | ||
170 | *revision_value = BIT((revision >> REVISION_SHIFT) & REVISION_MASK); | |
171 | ||
172 | return 0; | |
173 | } | |
174 | ||
175 | static int ti_cpufreq_setup_syscon_register(struct ti_cpufreq_data *opp_data) | |
176 | { | |
177 | struct device *dev = opp_data->cpu_dev; | |
178 | struct device_node *np = opp_data->opp_node; | |
179 | ||
180 | opp_data->syscon = syscon_regmap_lookup_by_phandle(np, | |
181 | "syscon"); | |
182 | if (IS_ERR(opp_data->syscon)) { | |
183 | dev_err(dev, | |
184 | "\"syscon\" is missing, cannot use OPPv2 table.\n"); | |
185 | return PTR_ERR(opp_data->syscon); | |
186 | } | |
187 | ||
188 | return 0; | |
189 | } | |
190 | ||
191 | static const struct of_device_id ti_cpufreq_of_match[] = { | |
192 | { .compatible = "ti,am33xx", .data = &am3x_soc_data, }, | |
193 | { .compatible = "ti,am4372", .data = &am4x_soc_data, }, | |
194 | { .compatible = "ti,dra7", .data = &dra7_soc_data }, | |
195 | {}, | |
196 | }; | |
197 | ||
198 | static int ti_cpufreq_init(void) | |
199 | { | |
200 | u32 version[VERSION_COUNT]; | |
201 | struct device_node *np; | |
202 | const struct of_device_id *match; | |
203 | struct ti_cpufreq_data *opp_data; | |
204 | int ret; | |
205 | ||
206 | np = of_find_node_by_path("/"); | |
207 | match = of_match_node(ti_cpufreq_of_match, np); | |
208 | if (!match) | |
209 | return -ENODEV; | |
210 | ||
211 | opp_data = kzalloc(sizeof(*opp_data), GFP_KERNEL); | |
212 | if (!opp_data) | |
213 | return -ENOMEM; | |
214 | ||
215 | opp_data->soc_data = match->data; | |
216 | ||
217 | opp_data->cpu_dev = get_cpu_device(0); | |
218 | if (!opp_data->cpu_dev) { | |
219 | pr_err("%s: Failed to get device for CPU0\n", __func__); | |
220 | return -ENODEV; | |
221 | } | |
222 | ||
223 | opp_data->opp_node = dev_pm_opp_of_get_opp_desc_node(opp_data->cpu_dev); | |
224 | if (!opp_data->opp_node) { | |
225 | dev_info(opp_data->cpu_dev, | |
226 | "OPP-v2 not supported, cpufreq-dt will attempt to use legacy tables.\n"); | |
227 | goto register_cpufreq_dt; | |
228 | } | |
229 | ||
230 | ret = ti_cpufreq_setup_syscon_register(opp_data); | |
231 | if (ret) | |
232 | goto fail_put_node; | |
233 | ||
234 | /* | |
235 | * OPPs determine whether or not they are supported based on | |
236 | * two metrics: | |
237 | * 0 - SoC Revision | |
238 | * 1 - eFuse value | |
239 | */ | |
240 | ret = ti_cpufreq_get_rev(opp_data, &version[0]); | |
241 | if (ret) | |
242 | goto fail_put_node; | |
243 | ||
244 | ret = ti_cpufreq_get_efuse(opp_data, &version[1]); | |
245 | if (ret) | |
246 | goto fail_put_node; | |
247 | ||
248 | of_node_put(opp_data->opp_node); | |
249 | ||
250 | ret = PTR_ERR_OR_ZERO(dev_pm_opp_set_supported_hw(opp_data->cpu_dev, | |
251 | version, VERSION_COUNT)); | |
252 | if (ret) { | |
253 | dev_err(opp_data->cpu_dev, | |
254 | "Failed to set supported hardware\n"); | |
255 | goto fail_put_node; | |
256 | } | |
257 | ||
258 | register_cpufreq_dt: | |
259 | platform_device_register_simple("cpufreq-dt", -1, NULL, 0); | |
260 | ||
261 | return 0; | |
262 | ||
263 | fail_put_node: | |
264 | of_node_put(opp_data->opp_node); | |
265 | ||
266 | return ret; | |
267 | } | |
268 | module_init(ti_cpufreq_init); | |
269 | ||
270 | MODULE_DESCRIPTION("TI CPUFreq/OPP hw-supported driver"); | |
271 | MODULE_AUTHOR("Dave Gerlach <d-gerlach@ti.com>"); | |
272 | MODULE_LICENSE("GPL v2"); |