xref: /openbmc/linux/drivers/cpufreq/ti-cpufreq.c (revision 078b39c9)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * TI CPUFreq/OPP hw-supported driver
4  *
5  * Copyright (C) 2016-2017 Texas Instruments, Inc.
6  *	 Dave Gerlach <d-gerlach@ti.com>
7  */
8 
9 #include <linux/cpu.h>
10 #include <linux/io.h>
11 #include <linux/mfd/syscon.h>
12 #include <linux/module.h>
13 #include <linux/init.h>
14 #include <linux/of.h>
15 #include <linux/of_platform.h>
16 #include <linux/pm_opp.h>
17 #include <linux/regmap.h>
18 #include <linux/slab.h>
19 
20 #define REVISION_MASK				0xF
21 #define REVISION_SHIFT				28
22 
23 #define AM33XX_800M_ARM_MPU_MAX_FREQ		0x1E2F
24 #define AM43XX_600M_ARM_MPU_MAX_FREQ		0xFFA
25 
26 #define DRA7_EFUSE_HAS_OD_MPU_OPP		11
27 #define DRA7_EFUSE_HAS_HIGH_MPU_OPP		15
28 #define DRA76_EFUSE_HAS_PLUS_MPU_OPP		18
29 #define DRA7_EFUSE_HAS_ALL_MPU_OPP		23
30 #define DRA76_EFUSE_HAS_ALL_MPU_OPP		24
31 
32 #define DRA7_EFUSE_NOM_MPU_OPP			BIT(0)
33 #define DRA7_EFUSE_OD_MPU_OPP			BIT(1)
34 #define DRA7_EFUSE_HIGH_MPU_OPP			BIT(2)
35 #define DRA76_EFUSE_PLUS_MPU_OPP		BIT(3)
36 
37 #define OMAP3_CONTROL_DEVICE_STATUS		0x4800244C
38 #define OMAP3_CONTROL_IDCODE			0x4830A204
39 #define OMAP34xx_ProdID_SKUID			0x4830A20C
40 #define OMAP3_SYSCON_BASE	(0x48000000 + 0x2000 + 0x270)
41 
42 #define AM625_EFUSE_K_MPU_OPP			11
43 #define AM625_EFUSE_S_MPU_OPP			19
44 #define AM625_EFUSE_T_MPU_OPP			20
45 
46 #define AM625_SUPPORT_K_MPU_OPP			BIT(0)
47 #define AM625_SUPPORT_S_MPU_OPP			BIT(1)
48 #define AM625_SUPPORT_T_MPU_OPP			BIT(2)
49 
50 #define VERSION_COUNT				2
51 
52 struct ti_cpufreq_data;
53 
54 struct ti_cpufreq_soc_data {
55 	const char * const *reg_names;
56 	unsigned long (*efuse_xlate)(struct ti_cpufreq_data *opp_data,
57 				     unsigned long efuse);
58 	unsigned long efuse_fallback;
59 	unsigned long efuse_offset;
60 	unsigned long efuse_mask;
61 	unsigned long efuse_shift;
62 	unsigned long rev_offset;
63 	bool multi_regulator;
64 };
65 
66 struct ti_cpufreq_data {
67 	struct device *cpu_dev;
68 	struct device_node *opp_node;
69 	struct regmap *syscon;
70 	const struct ti_cpufreq_soc_data *soc_data;
71 };
72 
73 static unsigned long amx3_efuse_xlate(struct ti_cpufreq_data *opp_data,
74 				      unsigned long efuse)
75 {
76 	if (!efuse)
77 		efuse = opp_data->soc_data->efuse_fallback;
78 	/* AM335x and AM437x use "OPP disable" bits, so invert */
79 	return ~efuse;
80 }
81 
82 static unsigned long dra7_efuse_xlate(struct ti_cpufreq_data *opp_data,
83 				      unsigned long efuse)
84 {
85 	unsigned long calculated_efuse = DRA7_EFUSE_NOM_MPU_OPP;
86 
87 	/*
88 	 * The efuse on dra7 and am57 parts contains a specific
89 	 * value indicating the highest available OPP.
90 	 */
91 
92 	switch (efuse) {
93 	case DRA76_EFUSE_HAS_PLUS_MPU_OPP:
94 	case DRA76_EFUSE_HAS_ALL_MPU_OPP:
95 		calculated_efuse |= DRA76_EFUSE_PLUS_MPU_OPP;
96 		fallthrough;
97 	case DRA7_EFUSE_HAS_ALL_MPU_OPP:
98 	case DRA7_EFUSE_HAS_HIGH_MPU_OPP:
99 		calculated_efuse |= DRA7_EFUSE_HIGH_MPU_OPP;
100 		fallthrough;
101 	case DRA7_EFUSE_HAS_OD_MPU_OPP:
102 		calculated_efuse |= DRA7_EFUSE_OD_MPU_OPP;
103 	}
104 
105 	return calculated_efuse;
106 }
107 
108 static unsigned long omap3_efuse_xlate(struct ti_cpufreq_data *opp_data,
109 				      unsigned long efuse)
110 {
111 	/* OPP enable bit ("Speed Binned") */
112 	return BIT(efuse);
113 }
114 
115 static unsigned long am625_efuse_xlate(struct ti_cpufreq_data *opp_data,
116 				       unsigned long efuse)
117 {
118 	unsigned long calculated_efuse = AM625_SUPPORT_K_MPU_OPP;
119 
120 	switch (efuse) {
121 	case AM625_EFUSE_T_MPU_OPP:
122 		calculated_efuse |= AM625_SUPPORT_T_MPU_OPP;
123 		fallthrough;
124 	case AM625_EFUSE_S_MPU_OPP:
125 		calculated_efuse |= AM625_SUPPORT_S_MPU_OPP;
126 		fallthrough;
127 	case AM625_EFUSE_K_MPU_OPP:
128 		calculated_efuse |= AM625_SUPPORT_K_MPU_OPP;
129 	}
130 
131 	return calculated_efuse;
132 }
133 
134 static struct ti_cpufreq_soc_data am3x_soc_data = {
135 	.efuse_xlate = amx3_efuse_xlate,
136 	.efuse_fallback = AM33XX_800M_ARM_MPU_MAX_FREQ,
137 	.efuse_offset = 0x07fc,
138 	.efuse_mask = 0x1fff,
139 	.rev_offset = 0x600,
140 	.multi_regulator = false,
141 };
142 
143 static struct ti_cpufreq_soc_data am4x_soc_data = {
144 	.efuse_xlate = amx3_efuse_xlate,
145 	.efuse_fallback = AM43XX_600M_ARM_MPU_MAX_FREQ,
146 	.efuse_offset = 0x0610,
147 	.efuse_mask = 0x3f,
148 	.rev_offset = 0x600,
149 	.multi_regulator = false,
150 };
151 
152 static struct ti_cpufreq_soc_data dra7_soc_data = {
153 	.efuse_xlate = dra7_efuse_xlate,
154 	.efuse_offset = 0x020c,
155 	.efuse_mask = 0xf80000,
156 	.efuse_shift = 19,
157 	.rev_offset = 0x204,
158 	.multi_regulator = true,
159 };
160 
161 /*
162  * OMAP35x TRM (SPRUF98K):
163  *  CONTROL_IDCODE (0x4830 A204) describes Silicon revisions.
164  *  Control OMAP Status Register 15:0 (Address 0x4800 244C)
165  *    to separate between omap3503, omap3515, omap3525, omap3530
166  *    and feature presence.
167  *    There are encodings for versions limited to 400/266MHz
168  *    but we ignore.
169  *    Not clear if this also holds for omap34xx.
170  *  some eFuse values e.g. CONTROL_FUSE_OPP1_VDD1
171  *    are stored in the SYSCON register range
172  *  Register 0x4830A20C [ProdID.SKUID] [0:3]
173  *    0x0 for normal 600/430MHz device.
174  *    0x8 for 720/520MHz device.
175  *    Not clear what omap34xx value is.
176  */
177 
178 static struct ti_cpufreq_soc_data omap34xx_soc_data = {
179 	.efuse_xlate = omap3_efuse_xlate,
180 	.efuse_offset = OMAP34xx_ProdID_SKUID - OMAP3_SYSCON_BASE,
181 	.efuse_shift = 3,
182 	.efuse_mask = BIT(3),
183 	.rev_offset = OMAP3_CONTROL_IDCODE - OMAP3_SYSCON_BASE,
184 	.multi_regulator = false,
185 };
186 
187 /*
188  * AM/DM37x TRM (SPRUGN4M)
189  *  CONTROL_IDCODE (0x4830 A204) describes Silicon revisions.
190  *  Control Device Status Register 15:0 (Address 0x4800 244C)
191  *    to separate between am3703, am3715, dm3725, dm3730
192  *    and feature presence.
193  *   Speed Binned = Bit 9
194  *     0 800/600 MHz
195  *     1 1000/800 MHz
196  *  some eFuse values e.g. CONTROL_FUSE_OPP 1G_VDD1
197  *    are stored in the SYSCON register range.
198  *  There is no 0x4830A20C [ProdID.SKUID] register (exists but
199  *    seems to always read as 0).
200  */
201 
202 static const char * const omap3_reg_names[] = {"cpu0", "vbb", NULL};
203 
204 static struct ti_cpufreq_soc_data omap36xx_soc_data = {
205 	.reg_names = omap3_reg_names,
206 	.efuse_xlate = omap3_efuse_xlate,
207 	.efuse_offset = OMAP3_CONTROL_DEVICE_STATUS - OMAP3_SYSCON_BASE,
208 	.efuse_shift = 9,
209 	.efuse_mask = BIT(9),
210 	.rev_offset = OMAP3_CONTROL_IDCODE - OMAP3_SYSCON_BASE,
211 	.multi_regulator = true,
212 };
213 
214 /*
215  * AM3517 is quite similar to AM/DM37x except that it has no
216  * high speed grade eFuse and no abb ldo
217  */
218 
219 static struct ti_cpufreq_soc_data am3517_soc_data = {
220 	.efuse_xlate = omap3_efuse_xlate,
221 	.efuse_offset = OMAP3_CONTROL_DEVICE_STATUS - OMAP3_SYSCON_BASE,
222 	.efuse_shift = 0,
223 	.efuse_mask = 0,
224 	.rev_offset = OMAP3_CONTROL_IDCODE - OMAP3_SYSCON_BASE,
225 	.multi_regulator = false,
226 };
227 
228 static struct ti_cpufreq_soc_data am625_soc_data = {
229 	.efuse_xlate = am625_efuse_xlate,
230 	.efuse_offset = 0x0018,
231 	.efuse_mask = 0x07c0,
232 	.efuse_shift = 0x6,
233 	.rev_offset = 0x0014,
234 	.multi_regulator = false,
235 };
236 
237 /**
238  * ti_cpufreq_get_efuse() - Parse and return efuse value present on SoC
239  * @opp_data: pointer to ti_cpufreq_data context
240  * @efuse_value: Set to the value parsed from efuse
241  *
242  * Returns error code if efuse not read properly.
243  */
244 static int ti_cpufreq_get_efuse(struct ti_cpufreq_data *opp_data,
245 				u32 *efuse_value)
246 {
247 	struct device *dev = opp_data->cpu_dev;
248 	u32 efuse;
249 	int ret;
250 
251 	ret = regmap_read(opp_data->syscon, opp_data->soc_data->efuse_offset,
252 			  &efuse);
253 	if (ret == -EIO) {
254 		/* not a syscon register! */
255 		void __iomem *regs = ioremap(OMAP3_SYSCON_BASE +
256 				opp_data->soc_data->efuse_offset, 4);
257 
258 		if (!regs)
259 			return -ENOMEM;
260 		efuse = readl(regs);
261 		iounmap(regs);
262 		}
263 	else if (ret) {
264 		dev_err(dev,
265 			"Failed to read the efuse value from syscon: %d\n",
266 			ret);
267 		return ret;
268 	}
269 
270 	efuse = (efuse & opp_data->soc_data->efuse_mask);
271 	efuse >>= opp_data->soc_data->efuse_shift;
272 
273 	*efuse_value = opp_data->soc_data->efuse_xlate(opp_data, efuse);
274 
275 	return 0;
276 }
277 
278 /**
279  * ti_cpufreq_get_rev() - Parse and return rev value present on SoC
280  * @opp_data: pointer to ti_cpufreq_data context
281  * @revision_value: Set to the value parsed from revision register
282  *
283  * Returns error code if revision not read properly.
284  */
285 static int ti_cpufreq_get_rev(struct ti_cpufreq_data *opp_data,
286 			      u32 *revision_value)
287 {
288 	struct device *dev = opp_data->cpu_dev;
289 	u32 revision;
290 	int ret;
291 
292 	ret = regmap_read(opp_data->syscon, opp_data->soc_data->rev_offset,
293 			  &revision);
294 	if (ret == -EIO) {
295 		/* not a syscon register! */
296 		void __iomem *regs = ioremap(OMAP3_SYSCON_BASE +
297 				opp_data->soc_data->rev_offset, 4);
298 
299 		if (!regs)
300 			return -ENOMEM;
301 		revision = readl(regs);
302 		iounmap(regs);
303 		}
304 	else if (ret) {
305 		dev_err(dev,
306 			"Failed to read the revision number from syscon: %d\n",
307 			ret);
308 		return ret;
309 	}
310 
311 	*revision_value = BIT((revision >> REVISION_SHIFT) & REVISION_MASK);
312 
313 	return 0;
314 }
315 
316 static int ti_cpufreq_setup_syscon_register(struct ti_cpufreq_data *opp_data)
317 {
318 	struct device *dev = opp_data->cpu_dev;
319 	struct device_node *np = opp_data->opp_node;
320 
321 	opp_data->syscon = syscon_regmap_lookup_by_phandle(np,
322 							"syscon");
323 	if (IS_ERR(opp_data->syscon)) {
324 		dev_err(dev,
325 			"\"syscon\" is missing, cannot use OPPv2 table.\n");
326 		return PTR_ERR(opp_data->syscon);
327 	}
328 
329 	return 0;
330 }
331 
332 static const struct of_device_id ti_cpufreq_of_match[] = {
333 	{ .compatible = "ti,am33xx", .data = &am3x_soc_data, },
334 	{ .compatible = "ti,am3517", .data = &am3517_soc_data, },
335 	{ .compatible = "ti,am43", .data = &am4x_soc_data, },
336 	{ .compatible = "ti,dra7", .data = &dra7_soc_data },
337 	{ .compatible = "ti,omap34xx", .data = &omap34xx_soc_data, },
338 	{ .compatible = "ti,omap36xx", .data = &omap36xx_soc_data, },
339 	{ .compatible = "ti,am625", .data = &am625_soc_data, },
340 	{ .compatible = "ti,am62a7", .data = &am625_soc_data, },
341 	/* legacy */
342 	{ .compatible = "ti,omap3430", .data = &omap34xx_soc_data, },
343 	{ .compatible = "ti,omap3630", .data = &omap36xx_soc_data, },
344 	{},
345 };
346 
347 static const struct of_device_id *ti_cpufreq_match_node(void)
348 {
349 	struct device_node *np;
350 	const struct of_device_id *match;
351 
352 	np = of_find_node_by_path("/");
353 	match = of_match_node(ti_cpufreq_of_match, np);
354 	of_node_put(np);
355 
356 	return match;
357 }
358 
359 static int ti_cpufreq_probe(struct platform_device *pdev)
360 {
361 	u32 version[VERSION_COUNT];
362 	const struct of_device_id *match;
363 	struct ti_cpufreq_data *opp_data;
364 	const char * const default_reg_names[] = {"vdd", "vbb", NULL};
365 	int ret;
366 	struct dev_pm_opp_config config = {
367 		.supported_hw = version,
368 		.supported_hw_count = ARRAY_SIZE(version),
369 	};
370 
371 	match = dev_get_platdata(&pdev->dev);
372 	if (!match)
373 		return -ENODEV;
374 
375 	opp_data = devm_kzalloc(&pdev->dev, sizeof(*opp_data), GFP_KERNEL);
376 	if (!opp_data)
377 		return -ENOMEM;
378 
379 	opp_data->soc_data = match->data;
380 
381 	opp_data->cpu_dev = get_cpu_device(0);
382 	if (!opp_data->cpu_dev) {
383 		pr_err("%s: Failed to get device for CPU0\n", __func__);
384 		return -ENODEV;
385 	}
386 
387 	opp_data->opp_node = dev_pm_opp_of_get_opp_desc_node(opp_data->cpu_dev);
388 	if (!opp_data->opp_node) {
389 		dev_info(opp_data->cpu_dev,
390 			 "OPP-v2 not supported, cpufreq-dt will attempt to use legacy tables.\n");
391 		goto register_cpufreq_dt;
392 	}
393 
394 	ret = ti_cpufreq_setup_syscon_register(opp_data);
395 	if (ret)
396 		goto fail_put_node;
397 
398 	/*
399 	 * OPPs determine whether or not they are supported based on
400 	 * two metrics:
401 	 *	0 - SoC Revision
402 	 *	1 - eFuse value
403 	 */
404 	ret = ti_cpufreq_get_rev(opp_data, &version[0]);
405 	if (ret)
406 		goto fail_put_node;
407 
408 	ret = ti_cpufreq_get_efuse(opp_data, &version[1]);
409 	if (ret)
410 		goto fail_put_node;
411 
412 	if (opp_data->soc_data->multi_regulator) {
413 		if (opp_data->soc_data->reg_names)
414 			config.regulator_names = opp_data->soc_data->reg_names;
415 		else
416 			config.regulator_names = default_reg_names;
417 	}
418 
419 	ret = dev_pm_opp_set_config(opp_data->cpu_dev, &config);
420 	if (ret < 0) {
421 		dev_err(opp_data->cpu_dev, "Failed to set OPP config\n");
422 		goto fail_put_node;
423 	}
424 
425 	of_node_put(opp_data->opp_node);
426 
427 register_cpufreq_dt:
428 	platform_device_register_simple("cpufreq-dt", -1, NULL, 0);
429 
430 	return 0;
431 
432 fail_put_node:
433 	of_node_put(opp_data->opp_node);
434 
435 	return ret;
436 }
437 
438 static int __init ti_cpufreq_init(void)
439 {
440 	const struct of_device_id *match;
441 
442 	/* Check to ensure we are on a compatible platform */
443 	match = ti_cpufreq_match_node();
444 	if (match)
445 		platform_device_register_data(NULL, "ti-cpufreq", -1, match,
446 					      sizeof(*match));
447 
448 	return 0;
449 }
450 module_init(ti_cpufreq_init);
451 
452 static struct platform_driver ti_cpufreq_driver = {
453 	.probe = ti_cpufreq_probe,
454 	.driver = {
455 		.name = "ti-cpufreq",
456 	},
457 };
458 builtin_platform_driver(ti_cpufreq_driver);
459 
460 MODULE_DESCRIPTION("TI CPUFreq/OPP hw-supported driver");
461 MODULE_AUTHOR("Dave Gerlach <d-gerlach@ti.com>");
462 MODULE_LICENSE("GPL v2");
463