1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2018, The Linux Foundation. All rights reserved.
4  */
5 
6 /*
7  * In Certain QCOM SoCs like apq8096 and msm8996 that have KRYO processors,
8  * the CPU frequency subset and voltage value of each OPP varies
9  * based on the silicon variant in use. Qualcomm Process Voltage Scaling Tables
10  * defines the voltage and frequency value based on the msm-id in SMEM
11  * and speedbin blown in the efuse combination.
12  * The qcom-cpufreq-nvmem driver reads the msm-id and efuse value from the SoC
13  * to provide the OPP framework with required information.
14  * This is used to determine the voltage and frequency value for each OPP of
15  * operating-points-v2 table when it is parsed by the OPP framework.
16  */
17 
18 #include <linux/cpu.h>
19 #include <linux/err.h>
20 #include <linux/init.h>
21 #include <linux/kernel.h>
22 #include <linux/module.h>
23 #include <linux/nvmem-consumer.h>
24 #include <linux/of.h>
25 #include <linux/of_device.h>
26 #include <linux/platform_device.h>
27 #include <linux/pm_domain.h>
28 #include <linux/pm_opp.h>
29 #include <linux/slab.h>
30 #include <linux/soc/qcom/smem.h>
31 
32 #define MSM_ID_SMEM	137
33 
34 enum _msm_id {
35 	MSM8996V3 = 0xF6ul,
36 	APQ8096V3 = 0x123ul,
37 	MSM8996SG = 0x131ul,
38 	APQ8096SG = 0x138ul,
39 };
40 
41 enum _msm8996_version {
42 	MSM8996_V3,
43 	MSM8996_SG,
44 	NUM_OF_MSM8996_VERSIONS,
45 };
46 
47 struct qcom_cpufreq_drv;
48 
49 struct qcom_cpufreq_match_data {
50 	int (*get_version)(struct device *cpu_dev,
51 			   struct nvmem_cell *speedbin_nvmem,
52 			   char **pvs_name,
53 			   struct qcom_cpufreq_drv *drv);
54 	const char **genpd_names;
55 };
56 
57 struct qcom_cpufreq_drv {
58 	int *opp_tokens;
59 	u32 versions;
60 	const struct qcom_cpufreq_match_data *data;
61 };
62 
63 static struct platform_device *cpufreq_dt_pdev, *cpufreq_pdev;
64 
65 static void get_krait_bin_format_a(struct device *cpu_dev,
66 					  int *speed, int *pvs, int *pvs_ver,
67 					  struct nvmem_cell *pvs_nvmem, u8 *buf)
68 {
69 	u32 pte_efuse;
70 
71 	pte_efuse = *((u32 *)buf);
72 
73 	*speed = pte_efuse & 0xf;
74 	if (*speed == 0xf)
75 		*speed = (pte_efuse >> 4) & 0xf;
76 
77 	if (*speed == 0xf) {
78 		*speed = 0;
79 		dev_warn(cpu_dev, "Speed bin: Defaulting to %d\n", *speed);
80 	} else {
81 		dev_dbg(cpu_dev, "Speed bin: %d\n", *speed);
82 	}
83 
84 	*pvs = (pte_efuse >> 10) & 0x7;
85 	if (*pvs == 0x7)
86 		*pvs = (pte_efuse >> 13) & 0x7;
87 
88 	if (*pvs == 0x7) {
89 		*pvs = 0;
90 		dev_warn(cpu_dev, "PVS bin: Defaulting to %d\n", *pvs);
91 	} else {
92 		dev_dbg(cpu_dev, "PVS bin: %d\n", *pvs);
93 	}
94 }
95 
96 static void get_krait_bin_format_b(struct device *cpu_dev,
97 					  int *speed, int *pvs, int *pvs_ver,
98 					  struct nvmem_cell *pvs_nvmem, u8 *buf)
99 {
100 	u32 pte_efuse, redundant_sel;
101 
102 	pte_efuse = *((u32 *)buf);
103 	redundant_sel = (pte_efuse >> 24) & 0x7;
104 
105 	*pvs_ver = (pte_efuse >> 4) & 0x3;
106 
107 	switch (redundant_sel) {
108 	case 1:
109 		*pvs = ((pte_efuse >> 28) & 0x8) | ((pte_efuse >> 6) & 0x7);
110 		*speed = (pte_efuse >> 27) & 0xf;
111 		break;
112 	case 2:
113 		*pvs = (pte_efuse >> 27) & 0xf;
114 		*speed = pte_efuse & 0x7;
115 		break;
116 	default:
117 		/* 4 bits of PVS are in efuse register bits 31, 8-6. */
118 		*pvs = ((pte_efuse >> 28) & 0x8) | ((pte_efuse >> 6) & 0x7);
119 		*speed = pte_efuse & 0x7;
120 	}
121 
122 	/* Check SPEED_BIN_BLOW_STATUS */
123 	if (pte_efuse & BIT(3)) {
124 		dev_dbg(cpu_dev, "Speed bin: %d\n", *speed);
125 	} else {
126 		dev_warn(cpu_dev, "Speed bin not set. Defaulting to 0!\n");
127 		*speed = 0;
128 	}
129 
130 	/* Check PVS_BLOW_STATUS */
131 	pte_efuse = *(((u32 *)buf) + 1);
132 	pte_efuse &= BIT(21);
133 	if (pte_efuse) {
134 		dev_dbg(cpu_dev, "PVS bin: %d\n", *pvs);
135 	} else {
136 		dev_warn(cpu_dev, "PVS bin not set. Defaulting to 0!\n");
137 		*pvs = 0;
138 	}
139 
140 	dev_dbg(cpu_dev, "PVS version: %d\n", *pvs_ver);
141 }
142 
143 static enum _msm8996_version qcom_cpufreq_get_msm_id(void)
144 {
145 	size_t len;
146 	u32 *msm_id;
147 	enum _msm8996_version version;
148 
149 	msm_id = qcom_smem_get(QCOM_SMEM_HOST_ANY, MSM_ID_SMEM, &len);
150 	if (IS_ERR(msm_id))
151 		return NUM_OF_MSM8996_VERSIONS;
152 
153 	/* The first 4 bytes are format, next to them is the actual msm-id */
154 	msm_id++;
155 
156 	switch ((enum _msm_id)*msm_id) {
157 	case MSM8996V3:
158 	case APQ8096V3:
159 		version = MSM8996_V3;
160 		break;
161 	case MSM8996SG:
162 	case APQ8096SG:
163 		version = MSM8996_SG;
164 		break;
165 	default:
166 		version = NUM_OF_MSM8996_VERSIONS;
167 	}
168 
169 	return version;
170 }
171 
172 static int qcom_cpufreq_kryo_name_version(struct device *cpu_dev,
173 					  struct nvmem_cell *speedbin_nvmem,
174 					  char **pvs_name,
175 					  struct qcom_cpufreq_drv *drv)
176 {
177 	size_t len;
178 	u8 *speedbin;
179 	enum _msm8996_version msm8996_version;
180 	*pvs_name = NULL;
181 
182 	msm8996_version = qcom_cpufreq_get_msm_id();
183 	if (NUM_OF_MSM8996_VERSIONS == msm8996_version) {
184 		dev_err(cpu_dev, "Not Snapdragon 820/821!");
185 		return -ENODEV;
186 	}
187 
188 	speedbin = nvmem_cell_read(speedbin_nvmem, &len);
189 	if (IS_ERR(speedbin))
190 		return PTR_ERR(speedbin);
191 
192 	switch (msm8996_version) {
193 	case MSM8996_V3:
194 		drv->versions = 1 << (unsigned int)(*speedbin);
195 		break;
196 	case MSM8996_SG:
197 		drv->versions = 1 << ((unsigned int)(*speedbin) + 4);
198 		break;
199 	default:
200 		BUG();
201 		break;
202 	}
203 
204 	kfree(speedbin);
205 	return 0;
206 }
207 
208 static int qcom_cpufreq_krait_name_version(struct device *cpu_dev,
209 					   struct nvmem_cell *speedbin_nvmem,
210 					   char **pvs_name,
211 					   struct qcom_cpufreq_drv *drv)
212 {
213 	int speed = 0, pvs = 0, pvs_ver = 0;
214 	u8 *speedbin;
215 	size_t len;
216 
217 	speedbin = nvmem_cell_read(speedbin_nvmem, &len);
218 
219 	if (IS_ERR(speedbin))
220 		return PTR_ERR(speedbin);
221 
222 	switch (len) {
223 	case 4:
224 		get_krait_bin_format_a(cpu_dev, &speed, &pvs, &pvs_ver,
225 				       speedbin_nvmem, speedbin);
226 		break;
227 	case 8:
228 		get_krait_bin_format_b(cpu_dev, &speed, &pvs, &pvs_ver,
229 				       speedbin_nvmem, speedbin);
230 		break;
231 	default:
232 		dev_err(cpu_dev, "Unable to read nvmem data. Defaulting to 0!\n");
233 		return -ENODEV;
234 	}
235 
236 	snprintf(*pvs_name, sizeof("speedXX-pvsXX-vXX"), "speed%d-pvs%d-v%d",
237 		 speed, pvs, pvs_ver);
238 
239 	drv->versions = (1 << speed);
240 
241 	kfree(speedbin);
242 	return 0;
243 }
244 
245 static const struct qcom_cpufreq_match_data match_data_kryo = {
246 	.get_version = qcom_cpufreq_kryo_name_version,
247 };
248 
249 static const struct qcom_cpufreq_match_data match_data_krait = {
250 	.get_version = qcom_cpufreq_krait_name_version,
251 };
252 
253 static const char *qcs404_genpd_names[] = { "cpr", NULL };
254 
255 static const struct qcom_cpufreq_match_data match_data_qcs404 = {
256 	.genpd_names = qcs404_genpd_names,
257 };
258 
259 static int qcom_cpufreq_probe(struct platform_device *pdev)
260 {
261 	struct qcom_cpufreq_drv *drv;
262 	struct nvmem_cell *speedbin_nvmem;
263 	struct device_node *np;
264 	struct device *cpu_dev;
265 	char *pvs_name = "speedXX-pvsXX-vXX";
266 	unsigned cpu;
267 	const struct of_device_id *match;
268 	int ret;
269 
270 	cpu_dev = get_cpu_device(0);
271 	if (!cpu_dev)
272 		return -ENODEV;
273 
274 	np = dev_pm_opp_of_get_opp_desc_node(cpu_dev);
275 	if (!np)
276 		return -ENOENT;
277 
278 	ret = of_device_is_compatible(np, "operating-points-v2-kryo-cpu");
279 	if (!ret) {
280 		of_node_put(np);
281 		return -ENOENT;
282 	}
283 
284 	drv = kzalloc(sizeof(*drv), GFP_KERNEL);
285 	if (!drv)
286 		return -ENOMEM;
287 
288 	match = pdev->dev.platform_data;
289 	drv->data = match->data;
290 	if (!drv->data) {
291 		ret = -ENODEV;
292 		goto free_drv;
293 	}
294 
295 	if (drv->data->get_version) {
296 		speedbin_nvmem = of_nvmem_cell_get(np, NULL);
297 		if (IS_ERR(speedbin_nvmem)) {
298 			if (PTR_ERR(speedbin_nvmem) != -EPROBE_DEFER)
299 				dev_err(cpu_dev,
300 					"Could not get nvmem cell: %ld\n",
301 					PTR_ERR(speedbin_nvmem));
302 			ret = PTR_ERR(speedbin_nvmem);
303 			goto free_drv;
304 		}
305 
306 		ret = drv->data->get_version(cpu_dev,
307 							speedbin_nvmem, &pvs_name, drv);
308 		if (ret) {
309 			nvmem_cell_put(speedbin_nvmem);
310 			goto free_drv;
311 		}
312 		nvmem_cell_put(speedbin_nvmem);
313 	}
314 	of_node_put(np);
315 
316 	drv->opp_tokens = kcalloc(num_possible_cpus(), sizeof(*drv->opp_tokens),
317 				  GFP_KERNEL);
318 	if (!drv->opp_tokens) {
319 		ret = -ENOMEM;
320 		goto free_drv;
321 	}
322 
323 	for_each_possible_cpu(cpu) {
324 		struct dev_pm_opp_config config = {
325 			.supported_hw = NULL,
326 		};
327 
328 		cpu_dev = get_cpu_device(cpu);
329 		if (NULL == cpu_dev) {
330 			ret = -ENODEV;
331 			goto free_opp;
332 		}
333 
334 		if (drv->data->get_version) {
335 			config.supported_hw = &drv->versions;
336 			config.supported_hw_count = 1;
337 
338 			if (pvs_name)
339 				config.prop_name = pvs_name;
340 		}
341 
342 		if (drv->data->genpd_names) {
343 			config.genpd_names = drv->data->genpd_names;
344 			config.virt_devs = NULL;
345 		}
346 
347 		if (config.supported_hw || config.genpd_names) {
348 			drv->opp_tokens[cpu] = dev_pm_opp_set_config(cpu_dev, &config);
349 			if (drv->opp_tokens[cpu] < 0) {
350 				ret = drv->opp_tokens[cpu];
351 				dev_err(cpu_dev, "Failed to set OPP config\n");
352 				goto free_opp;
353 			}
354 		}
355 	}
356 
357 	cpufreq_dt_pdev = platform_device_register_simple("cpufreq-dt", -1,
358 							  NULL, 0);
359 	if (!IS_ERR(cpufreq_dt_pdev)) {
360 		platform_set_drvdata(pdev, drv);
361 		return 0;
362 	}
363 
364 	ret = PTR_ERR(cpufreq_dt_pdev);
365 	dev_err(cpu_dev, "Failed to register platform device\n");
366 
367 free_opp:
368 	for_each_possible_cpu(cpu)
369 		dev_pm_opp_clear_config(drv->opp_tokens[cpu]);
370 	kfree(drv->opp_tokens);
371 free_drv:
372 	kfree(drv);
373 
374 	return ret;
375 }
376 
377 static int qcom_cpufreq_remove(struct platform_device *pdev)
378 {
379 	struct qcom_cpufreq_drv *drv = platform_get_drvdata(pdev);
380 	unsigned int cpu;
381 
382 	platform_device_unregister(cpufreq_dt_pdev);
383 
384 	for_each_possible_cpu(cpu)
385 		dev_pm_opp_clear_config(drv->opp_tokens[cpu]);
386 
387 	kfree(drv->opp_tokens);
388 	kfree(drv);
389 
390 	return 0;
391 }
392 
393 static struct platform_driver qcom_cpufreq_driver = {
394 	.probe = qcom_cpufreq_probe,
395 	.remove = qcom_cpufreq_remove,
396 	.driver = {
397 		.name = "qcom-cpufreq-nvmem",
398 	},
399 };
400 
401 static const struct of_device_id qcom_cpufreq_match_list[] __initconst = {
402 	{ .compatible = "qcom,apq8096", .data = &match_data_kryo },
403 	{ .compatible = "qcom,msm8996", .data = &match_data_kryo },
404 	{ .compatible = "qcom,qcs404", .data = &match_data_qcs404 },
405 	{ .compatible = "qcom,ipq8064", .data = &match_data_krait },
406 	{ .compatible = "qcom,apq8064", .data = &match_data_krait },
407 	{ .compatible = "qcom,msm8974", .data = &match_data_krait },
408 	{ .compatible = "qcom,msm8960", .data = &match_data_krait },
409 	{},
410 };
411 MODULE_DEVICE_TABLE(of, qcom_cpufreq_match_list);
412 
413 /*
414  * Since the driver depends on smem and nvmem drivers, which may
415  * return EPROBE_DEFER, all the real activity is done in the probe,
416  * which may be defered as well. The init here is only registering
417  * the driver and the platform device.
418  */
419 static int __init qcom_cpufreq_init(void)
420 {
421 	struct device_node *np = of_find_node_by_path("/");
422 	const struct of_device_id *match;
423 	int ret;
424 
425 	if (!np)
426 		return -ENODEV;
427 
428 	match = of_match_node(qcom_cpufreq_match_list, np);
429 	of_node_put(np);
430 	if (!match)
431 		return -ENODEV;
432 
433 	ret = platform_driver_register(&qcom_cpufreq_driver);
434 	if (unlikely(ret < 0))
435 		return ret;
436 
437 	cpufreq_pdev = platform_device_register_data(NULL, "qcom-cpufreq-nvmem",
438 						     -1, match, sizeof(*match));
439 	ret = PTR_ERR_OR_ZERO(cpufreq_pdev);
440 	if (0 == ret)
441 		return 0;
442 
443 	platform_driver_unregister(&qcom_cpufreq_driver);
444 	return ret;
445 }
446 module_init(qcom_cpufreq_init);
447 
448 static void __exit qcom_cpufreq_exit(void)
449 {
450 	platform_device_unregister(cpufreq_pdev);
451 	platform_driver_unregister(&qcom_cpufreq_driver);
452 }
453 module_exit(qcom_cpufreq_exit);
454 
455 MODULE_DESCRIPTION("Qualcomm Technologies, Inc. CPUfreq driver");
456 MODULE_LICENSE("GPL v2");
457