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/init.h>
22 #include <linux/of.h>
23 #include <linux/of_platform.h>
24 #include <linux/pm_opp.h>
25 #include <linux/regmap.h>
26 #include <linux/slab.h>
27
28 #define REVISION_MASK 0xF
29 #define REVISION_SHIFT 28
30
31 #define AM33XX_800M_ARM_MPU_MAX_FREQ 0x1E2F
32 #define AM43XX_600M_ARM_MPU_MAX_FREQ 0xFFA
33
34 #define DRA7_EFUSE_HAS_OD_MPU_OPP 11
35 #define DRA7_EFUSE_HAS_HIGH_MPU_OPP 15
36 #define DRA7_EFUSE_HAS_ALL_MPU_OPP 23
37
38 #define DRA7_EFUSE_NOM_MPU_OPP BIT(0)
39 #define DRA7_EFUSE_OD_MPU_OPP BIT(1)
40 #define DRA7_EFUSE_HIGH_MPU_OPP BIT(2)
41
42 #define VERSION_COUNT 2
43
44 struct ti_cpufreq_data;
45
46 struct ti_cpufreq_soc_data {
47 unsigned long (*efuse_xlate)(struct ti_cpufreq_data *opp_data,
48 unsigned long efuse);
49 unsigned long efuse_fallback;
50 unsigned long efuse_offset;
51 unsigned long efuse_mask;
52 unsigned long efuse_shift;
53 unsigned long rev_offset;
54 bool multi_regulator;
55 };
56
57 struct ti_cpufreq_data {
58 struct device *cpu_dev;
59 struct device_node *opp_node;
60 struct regmap *syscon;
61 const struct ti_cpufreq_soc_data *soc_data;
62 struct opp_table *opp_table;
63 };
64
amx3_efuse_xlate(struct ti_cpufreq_data * opp_data,unsigned long efuse)65 static unsigned long amx3_efuse_xlate(struct ti_cpufreq_data *opp_data,
66 unsigned long efuse)
67 {
68 if (!efuse)
69 efuse = opp_data->soc_data->efuse_fallback;
70 /* AM335x and AM437x use "OPP disable" bits, so invert */
71 return ~efuse;
72 }
73
dra7_efuse_xlate(struct ti_cpufreq_data * opp_data,unsigned long efuse)74 static unsigned long dra7_efuse_xlate(struct ti_cpufreq_data *opp_data,
75 unsigned long efuse)
76 {
77 unsigned long calculated_efuse = DRA7_EFUSE_NOM_MPU_OPP;
78
79 /*
80 * The efuse on dra7 and am57 parts contains a specific
81 * value indicating the highest available OPP.
82 */
83
84 switch (efuse) {
85 case DRA7_EFUSE_HAS_ALL_MPU_OPP:
86 case DRA7_EFUSE_HAS_HIGH_MPU_OPP:
87 calculated_efuse |= DRA7_EFUSE_HIGH_MPU_OPP;
88 case DRA7_EFUSE_HAS_OD_MPU_OPP:
89 calculated_efuse |= DRA7_EFUSE_OD_MPU_OPP;
90 }
91
92 return calculated_efuse;
93 }
94
95 static struct ti_cpufreq_soc_data am3x_soc_data = {
96 .efuse_xlate = amx3_efuse_xlate,
97 .efuse_fallback = AM33XX_800M_ARM_MPU_MAX_FREQ,
98 .efuse_offset = 0x07fc,
99 .efuse_mask = 0x1fff,
100 .rev_offset = 0x600,
101 .multi_regulator = false,
102 };
103
104 static struct ti_cpufreq_soc_data am4x_soc_data = {
105 .efuse_xlate = amx3_efuse_xlate,
106 .efuse_fallback = AM43XX_600M_ARM_MPU_MAX_FREQ,
107 .efuse_offset = 0x0610,
108 .efuse_mask = 0x3f,
109 .rev_offset = 0x600,
110 .multi_regulator = false,
111 };
112
113 static struct ti_cpufreq_soc_data dra7_soc_data = {
114 .efuse_xlate = dra7_efuse_xlate,
115 .efuse_offset = 0x020c,
116 .efuse_mask = 0xf80000,
117 .efuse_shift = 19,
118 .rev_offset = 0x204,
119 .multi_regulator = true,
120 };
121
122 /**
123 * ti_cpufreq_get_efuse() - Parse and return efuse value present on SoC
124 * @opp_data: pointer to ti_cpufreq_data context
125 * @efuse_value: Set to the value parsed from efuse
126 *
127 * Returns error code if efuse not read properly.
128 */
ti_cpufreq_get_efuse(struct ti_cpufreq_data * opp_data,u32 * efuse_value)129 static int ti_cpufreq_get_efuse(struct ti_cpufreq_data *opp_data,
130 u32 *efuse_value)
131 {
132 struct device *dev = opp_data->cpu_dev;
133 u32 efuse;
134 int ret;
135
136 ret = regmap_read(opp_data->syscon, opp_data->soc_data->efuse_offset,
137 &efuse);
138 if (ret) {
139 dev_err(dev,
140 "Failed to read the efuse value from syscon: %d\n",
141 ret);
142 return ret;
143 }
144
145 efuse = (efuse & opp_data->soc_data->efuse_mask);
146 efuse >>= opp_data->soc_data->efuse_shift;
147
148 *efuse_value = opp_data->soc_data->efuse_xlate(opp_data, efuse);
149
150 return 0;
151 }
152
153 /**
154 * ti_cpufreq_get_rev() - Parse and return rev value present on SoC
155 * @opp_data: pointer to ti_cpufreq_data context
156 * @revision_value: Set to the value parsed from revision register
157 *
158 * Returns error code if revision not read properly.
159 */
ti_cpufreq_get_rev(struct ti_cpufreq_data * opp_data,u32 * revision_value)160 static int ti_cpufreq_get_rev(struct ti_cpufreq_data *opp_data,
161 u32 *revision_value)
162 {
163 struct device *dev = opp_data->cpu_dev;
164 u32 revision;
165 int ret;
166
167 ret = regmap_read(opp_data->syscon, opp_data->soc_data->rev_offset,
168 &revision);
169 if (ret) {
170 dev_err(dev,
171 "Failed to read the revision number from syscon: %d\n",
172 ret);
173 return ret;
174 }
175
176 *revision_value = BIT((revision >> REVISION_SHIFT) & REVISION_MASK);
177
178 return 0;
179 }
180
ti_cpufreq_setup_syscon_register(struct ti_cpufreq_data * opp_data)181 static int ti_cpufreq_setup_syscon_register(struct ti_cpufreq_data *opp_data)
182 {
183 struct device *dev = opp_data->cpu_dev;
184 struct device_node *np = opp_data->opp_node;
185
186 opp_data->syscon = syscon_regmap_lookup_by_phandle(np,
187 "syscon");
188 if (IS_ERR(opp_data->syscon)) {
189 dev_err(dev,
190 "\"syscon\" is missing, cannot use OPPv2 table.\n");
191 return PTR_ERR(opp_data->syscon);
192 }
193
194 return 0;
195 }
196
197 static const struct of_device_id ti_cpufreq_of_match[] = {
198 { .compatible = "ti,am33xx", .data = &am3x_soc_data, },
199 { .compatible = "ti,am43", .data = &am4x_soc_data, },
200 { .compatible = "ti,dra7", .data = &dra7_soc_data },
201 {},
202 };
203
ti_cpufreq_probe(struct platform_device * pdev)204 static int ti_cpufreq_probe(struct platform_device *pdev)
205 {
206 u32 version[VERSION_COUNT];
207 struct device_node *np;
208 const struct of_device_id *match;
209 struct opp_table *ti_opp_table;
210 struct ti_cpufreq_data *opp_data;
211 const char * const reg_names[] = {"vdd", "vbb"};
212 int ret;
213
214 np = of_find_node_by_path("/");
215 match = of_match_node(ti_cpufreq_of_match, np);
216 of_node_put(np);
217 if (!match)
218 return -ENODEV;
219
220 opp_data = devm_kzalloc(&pdev->dev, sizeof(*opp_data), GFP_KERNEL);
221 if (!opp_data)
222 return -ENOMEM;
223
224 opp_data->soc_data = match->data;
225
226 opp_data->cpu_dev = get_cpu_device(0);
227 if (!opp_data->cpu_dev) {
228 pr_err("%s: Failed to get device for CPU0\n", __func__);
229 return -ENODEV;
230 }
231
232 opp_data->opp_node = dev_pm_opp_of_get_opp_desc_node(opp_data->cpu_dev);
233 if (!opp_data->opp_node) {
234 dev_info(opp_data->cpu_dev,
235 "OPP-v2 not supported, cpufreq-dt will attempt to use legacy tables.\n");
236 goto register_cpufreq_dt;
237 }
238
239 ret = ti_cpufreq_setup_syscon_register(opp_data);
240 if (ret)
241 goto fail_put_node;
242
243 /*
244 * OPPs determine whether or not they are supported based on
245 * two metrics:
246 * 0 - SoC Revision
247 * 1 - eFuse value
248 */
249 ret = ti_cpufreq_get_rev(opp_data, &version[0]);
250 if (ret)
251 goto fail_put_node;
252
253 ret = ti_cpufreq_get_efuse(opp_data, &version[1]);
254 if (ret)
255 goto fail_put_node;
256
257 ti_opp_table = dev_pm_opp_set_supported_hw(opp_data->cpu_dev,
258 version, VERSION_COUNT);
259 if (IS_ERR(ti_opp_table)) {
260 dev_err(opp_data->cpu_dev,
261 "Failed to set supported hardware\n");
262 ret = PTR_ERR(ti_opp_table);
263 goto fail_put_node;
264 }
265
266 opp_data->opp_table = ti_opp_table;
267
268 if (opp_data->soc_data->multi_regulator) {
269 ti_opp_table = dev_pm_opp_set_regulators(opp_data->cpu_dev,
270 reg_names,
271 ARRAY_SIZE(reg_names));
272 if (IS_ERR(ti_opp_table)) {
273 dev_pm_opp_put_supported_hw(opp_data->opp_table);
274 ret = PTR_ERR(ti_opp_table);
275 goto fail_put_node;
276 }
277 }
278
279 of_node_put(opp_data->opp_node);
280 register_cpufreq_dt:
281 platform_device_register_simple("cpufreq-dt", -1, NULL, 0);
282
283 return 0;
284
285 fail_put_node:
286 of_node_put(opp_data->opp_node);
287
288 return ret;
289 }
290
ti_cpufreq_init(void)291 static int ti_cpufreq_init(void)
292 {
293 platform_device_register_simple("ti-cpufreq", -1, NULL, 0);
294 return 0;
295 }
296 module_init(ti_cpufreq_init);
297
298 static struct platform_driver ti_cpufreq_driver = {
299 .probe = ti_cpufreq_probe,
300 .driver = {
301 .name = "ti-cpufreq",
302 },
303 };
304 builtin_platform_driver(ti_cpufreq_driver);
305
306 MODULE_DESCRIPTION("TI CPUFreq/OPP hw-supported driver");
307 MODULE_AUTHOR("Dave Gerlach <d-gerlach@ti.com>");
308 MODULE_LICENSE("GPL v2");
309
