1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (c) 2020 MediaTek Inc.
4 */
5
6 #include <linux/bitfield.h>
7 #include <linux/cpufreq.h>
8 #include <linux/energy_model.h>
9 #include <linux/init.h>
10 #include <linux/iopoll.h>
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/of.h>
14 #include <linux/of_platform.h>
15 #include <linux/platform_device.h>
16 #include <linux/regulator/consumer.h>
17 #include <linux/slab.h>
18
19 #define LUT_MAX_ENTRIES 32U
20 #define LUT_FREQ GENMASK(11, 0)
21 #define LUT_ROW_SIZE 0x4
22 #define CPUFREQ_HW_STATUS BIT(0)
23 #define SVS_HW_STATUS BIT(1)
24 #define POLL_USEC 1000
25 #define TIMEOUT_USEC 300000
26
27 enum {
28 REG_FREQ_LUT_TABLE,
29 REG_FREQ_ENABLE,
30 REG_FREQ_PERF_STATE,
31 REG_FREQ_HW_STATE,
32 REG_EM_POWER_TBL,
33 REG_FREQ_LATENCY,
34
35 REG_ARRAY_SIZE,
36 };
37
38 struct mtk_cpufreq_data {
39 struct cpufreq_frequency_table *table;
40 void __iomem *reg_bases[REG_ARRAY_SIZE];
41 struct resource *res;
42 void __iomem *base;
43 int nr_opp;
44 };
45
46 static const u16 cpufreq_mtk_offsets[REG_ARRAY_SIZE] = {
47 [REG_FREQ_LUT_TABLE] = 0x0,
48 [REG_FREQ_ENABLE] = 0x84,
49 [REG_FREQ_PERF_STATE] = 0x88,
50 [REG_FREQ_HW_STATE] = 0x8c,
51 [REG_EM_POWER_TBL] = 0x90,
52 [REG_FREQ_LATENCY] = 0x110,
53 };
54
55 static int __maybe_unused
mtk_cpufreq_get_cpu_power(struct device * cpu_dev,unsigned long * uW,unsigned long * KHz)56 mtk_cpufreq_get_cpu_power(struct device *cpu_dev, unsigned long *uW,
57 unsigned long *KHz)
58 {
59 struct mtk_cpufreq_data *data;
60 struct cpufreq_policy *policy;
61 int i;
62
63 policy = cpufreq_cpu_get_raw(cpu_dev->id);
64 if (!policy)
65 return 0;
66
67 data = policy->driver_data;
68
69 for (i = 0; i < data->nr_opp; i++) {
70 if (data->table[i].frequency < *KHz)
71 break;
72 }
73 i--;
74
75 *KHz = data->table[i].frequency;
76 /* Provide micro-Watts value to the Energy Model */
77 *uW = readl_relaxed(data->reg_bases[REG_EM_POWER_TBL] +
78 i * LUT_ROW_SIZE);
79
80 return 0;
81 }
82
mtk_cpufreq_hw_target_index(struct cpufreq_policy * policy,unsigned int index)83 static int mtk_cpufreq_hw_target_index(struct cpufreq_policy *policy,
84 unsigned int index)
85 {
86 struct mtk_cpufreq_data *data = policy->driver_data;
87
88 writel_relaxed(index, data->reg_bases[REG_FREQ_PERF_STATE]);
89
90 return 0;
91 }
92
mtk_cpufreq_hw_get(unsigned int cpu)93 static unsigned int mtk_cpufreq_hw_get(unsigned int cpu)
94 {
95 struct mtk_cpufreq_data *data;
96 struct cpufreq_policy *policy;
97 unsigned int index;
98
99 policy = cpufreq_cpu_get_raw(cpu);
100 if (!policy)
101 return 0;
102
103 data = policy->driver_data;
104
105 index = readl_relaxed(data->reg_bases[REG_FREQ_PERF_STATE]);
106 index = min(index, LUT_MAX_ENTRIES - 1);
107
108 return data->table[index].frequency;
109 }
110
mtk_cpufreq_hw_fast_switch(struct cpufreq_policy * policy,unsigned int target_freq)111 static unsigned int mtk_cpufreq_hw_fast_switch(struct cpufreq_policy *policy,
112 unsigned int target_freq)
113 {
114 struct mtk_cpufreq_data *data = policy->driver_data;
115 unsigned int index;
116
117 index = cpufreq_table_find_index_dl(policy, target_freq, false);
118
119 writel_relaxed(index, data->reg_bases[REG_FREQ_PERF_STATE]);
120
121 return policy->freq_table[index].frequency;
122 }
123
mtk_cpu_create_freq_table(struct platform_device * pdev,struct mtk_cpufreq_data * data)124 static int mtk_cpu_create_freq_table(struct platform_device *pdev,
125 struct mtk_cpufreq_data *data)
126 {
127 struct device *dev = &pdev->dev;
128 u32 temp, i, freq, prev_freq = 0;
129 void __iomem *base_table;
130
131 data->table = devm_kcalloc(dev, LUT_MAX_ENTRIES + 1,
132 sizeof(*data->table), GFP_KERNEL);
133 if (!data->table)
134 return -ENOMEM;
135
136 base_table = data->reg_bases[REG_FREQ_LUT_TABLE];
137
138 for (i = 0; i < LUT_MAX_ENTRIES; i++) {
139 temp = readl_relaxed(base_table + (i * LUT_ROW_SIZE));
140 freq = FIELD_GET(LUT_FREQ, temp) * 1000;
141
142 if (freq == prev_freq)
143 break;
144
145 data->table[i].frequency = freq;
146
147 dev_dbg(dev, "index=%d freq=%d\n", i, data->table[i].frequency);
148
149 prev_freq = freq;
150 }
151
152 data->table[i].frequency = CPUFREQ_TABLE_END;
153 data->nr_opp = i;
154
155 return 0;
156 }
157
mtk_cpu_resources_init(struct platform_device * pdev,struct cpufreq_policy * policy,const u16 * offsets)158 static int mtk_cpu_resources_init(struct platform_device *pdev,
159 struct cpufreq_policy *policy,
160 const u16 *offsets)
161 {
162 struct mtk_cpufreq_data *data;
163 struct device *dev = &pdev->dev;
164 struct resource *res;
165 struct of_phandle_args args;
166 void __iomem *base;
167 int ret, i;
168 int index;
169
170 data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
171 if (!data)
172 return -ENOMEM;
173
174 ret = of_perf_domain_get_sharing_cpumask(policy->cpu, "performance-domains",
175 "#performance-domain-cells",
176 policy->cpus, &args);
177 if (ret < 0)
178 return ret;
179
180 index = args.args[0];
181 of_node_put(args.np);
182
183 res = platform_get_resource(pdev, IORESOURCE_MEM, index);
184 if (!res) {
185 dev_err(dev, "failed to get mem resource %d\n", index);
186 return -ENODEV;
187 }
188
189 if (!request_mem_region(res->start, resource_size(res), res->name)) {
190 dev_err(dev, "failed to request resource %pR\n", res);
191 return -EBUSY;
192 }
193
194 base = ioremap(res->start, resource_size(res));
195 if (!base) {
196 dev_err(dev, "failed to map resource %pR\n", res);
197 ret = -ENOMEM;
198 goto release_region;
199 }
200
201 data->base = base;
202 data->res = res;
203
204 for (i = REG_FREQ_LUT_TABLE; i < REG_ARRAY_SIZE; i++)
205 data->reg_bases[i] = base + offsets[i];
206
207 ret = mtk_cpu_create_freq_table(pdev, data);
208 if (ret) {
209 dev_info(dev, "Domain-%d failed to create freq table\n", index);
210 return ret;
211 }
212
213 policy->freq_table = data->table;
214 policy->driver_data = data;
215
216 return 0;
217 release_region:
218 release_mem_region(res->start, resource_size(res));
219 return ret;
220 }
221
mtk_cpufreq_hw_cpu_init(struct cpufreq_policy * policy)222 static int mtk_cpufreq_hw_cpu_init(struct cpufreq_policy *policy)
223 {
224 struct platform_device *pdev = cpufreq_get_driver_data();
225 int sig, pwr_hw = CPUFREQ_HW_STATUS | SVS_HW_STATUS;
226 struct mtk_cpufreq_data *data;
227 unsigned int latency;
228 int ret;
229
230 /* Get the bases of cpufreq for domains */
231 ret = mtk_cpu_resources_init(pdev, policy, platform_get_drvdata(pdev));
232 if (ret) {
233 dev_info(&pdev->dev, "CPUFreq resource init failed\n");
234 return ret;
235 }
236
237 data = policy->driver_data;
238
239 latency = readl_relaxed(data->reg_bases[REG_FREQ_LATENCY]) * 1000;
240 if (!latency)
241 latency = CPUFREQ_ETERNAL;
242
243 policy->cpuinfo.transition_latency = latency;
244 policy->fast_switch_possible = true;
245
246 /* HW should be in enabled state to proceed now */
247 writel_relaxed(0x1, data->reg_bases[REG_FREQ_ENABLE]);
248 if (readl_poll_timeout(data->reg_bases[REG_FREQ_HW_STATE], sig,
249 (sig & pwr_hw) == pwr_hw, POLL_USEC,
250 TIMEOUT_USEC)) {
251 if (!(sig & CPUFREQ_HW_STATUS)) {
252 pr_info("cpufreq hardware of CPU%d is not enabled\n",
253 policy->cpu);
254 return -ENODEV;
255 }
256
257 pr_info("SVS of CPU%d is not enabled\n", policy->cpu);
258 }
259
260 return 0;
261 }
262
mtk_cpufreq_hw_cpu_exit(struct cpufreq_policy * policy)263 static int mtk_cpufreq_hw_cpu_exit(struct cpufreq_policy *policy)
264 {
265 struct mtk_cpufreq_data *data = policy->driver_data;
266 struct resource *res = data->res;
267 void __iomem *base = data->base;
268
269 /* HW should be in paused state now */
270 writel_relaxed(0x0, data->reg_bases[REG_FREQ_ENABLE]);
271 iounmap(base);
272 release_mem_region(res->start, resource_size(res));
273
274 return 0;
275 }
276
mtk_cpufreq_register_em(struct cpufreq_policy * policy)277 static void mtk_cpufreq_register_em(struct cpufreq_policy *policy)
278 {
279 struct em_data_callback em_cb = EM_DATA_CB(mtk_cpufreq_get_cpu_power);
280 struct mtk_cpufreq_data *data = policy->driver_data;
281
282 em_dev_register_perf_domain(get_cpu_device(policy->cpu), data->nr_opp,
283 &em_cb, policy->cpus, true);
284 }
285
286 static struct cpufreq_driver cpufreq_mtk_hw_driver = {
287 .flags = CPUFREQ_NEED_INITIAL_FREQ_CHECK |
288 CPUFREQ_HAVE_GOVERNOR_PER_POLICY |
289 CPUFREQ_IS_COOLING_DEV,
290 .verify = cpufreq_generic_frequency_table_verify,
291 .target_index = mtk_cpufreq_hw_target_index,
292 .get = mtk_cpufreq_hw_get,
293 .init = mtk_cpufreq_hw_cpu_init,
294 .exit = mtk_cpufreq_hw_cpu_exit,
295 .register_em = mtk_cpufreq_register_em,
296 .fast_switch = mtk_cpufreq_hw_fast_switch,
297 .name = "mtk-cpufreq-hw",
298 .attr = cpufreq_generic_attr,
299 };
300
mtk_cpufreq_hw_driver_probe(struct platform_device * pdev)301 static int mtk_cpufreq_hw_driver_probe(struct platform_device *pdev)
302 {
303 const void *data;
304 int ret, cpu;
305 struct device *cpu_dev;
306 struct regulator *cpu_reg;
307
308 /* Make sure that all CPU supplies are available before proceeding. */
309 for_each_possible_cpu(cpu) {
310 cpu_dev = get_cpu_device(cpu);
311 if (!cpu_dev)
312 return dev_err_probe(&pdev->dev, -EPROBE_DEFER,
313 "Failed to get cpu%d device\n", cpu);
314
315 cpu_reg = devm_regulator_get(cpu_dev, "cpu");
316 if (IS_ERR(cpu_reg))
317 return dev_err_probe(&pdev->dev, PTR_ERR(cpu_reg),
318 "CPU%d regulator get failed\n", cpu);
319 }
320
321
322 data = of_device_get_match_data(&pdev->dev);
323 if (!data)
324 return -EINVAL;
325
326 platform_set_drvdata(pdev, (void *) data);
327 cpufreq_mtk_hw_driver.driver_data = pdev;
328
329 ret = cpufreq_register_driver(&cpufreq_mtk_hw_driver);
330 if (ret)
331 dev_err(&pdev->dev, "CPUFreq HW driver failed to register\n");
332
333 return ret;
334 }
335
mtk_cpufreq_hw_driver_remove(struct platform_device * pdev)336 static void mtk_cpufreq_hw_driver_remove(struct platform_device *pdev)
337 {
338 cpufreq_unregister_driver(&cpufreq_mtk_hw_driver);
339 }
340
341 static const struct of_device_id mtk_cpufreq_hw_match[] = {
342 { .compatible = "mediatek,cpufreq-hw", .data = &cpufreq_mtk_offsets },
343 {}
344 };
345 MODULE_DEVICE_TABLE(of, mtk_cpufreq_hw_match);
346
347 static struct platform_driver mtk_cpufreq_hw_driver = {
348 .probe = mtk_cpufreq_hw_driver_probe,
349 .remove_new = mtk_cpufreq_hw_driver_remove,
350 .driver = {
351 .name = "mtk-cpufreq-hw",
352 .of_match_table = mtk_cpufreq_hw_match,
353 },
354 };
355 module_platform_driver(mtk_cpufreq_hw_driver);
356
357 MODULE_AUTHOR("Hector Yuan <hector.yuan@mediatek.com>");
358 MODULE_DESCRIPTION("Mediatek cpufreq-hw driver");
359 MODULE_LICENSE("GPL v2");
360