xref: /openbmc/linux/drivers/cpufreq/ti-cpufreq.c (revision fb4a5dfc)
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 VERSION_COUNT				2
43 
44 struct ti_cpufreq_data;
45 
46 struct ti_cpufreq_soc_data {
47 	const char * const *reg_names;
48 	unsigned long (*efuse_xlate)(struct ti_cpufreq_data *opp_data,
49 				     unsigned long efuse);
50 	unsigned long efuse_fallback;
51 	unsigned long efuse_offset;
52 	unsigned long efuse_mask;
53 	unsigned long efuse_shift;
54 	unsigned long rev_offset;
55 	bool multi_regulator;
56 };
57 
58 struct ti_cpufreq_data {
59 	struct device *cpu_dev;
60 	struct device_node *opp_node;
61 	struct regmap *syscon;
62 	const struct ti_cpufreq_soc_data *soc_data;
63 };
64 
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 
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 DRA76_EFUSE_HAS_PLUS_MPU_OPP:
86 	case DRA76_EFUSE_HAS_ALL_MPU_OPP:
87 		calculated_efuse |= DRA76_EFUSE_PLUS_MPU_OPP;
88 		fallthrough;
89 	case DRA7_EFUSE_HAS_ALL_MPU_OPP:
90 	case DRA7_EFUSE_HAS_HIGH_MPU_OPP:
91 		calculated_efuse |= DRA7_EFUSE_HIGH_MPU_OPP;
92 		fallthrough;
93 	case DRA7_EFUSE_HAS_OD_MPU_OPP:
94 		calculated_efuse |= DRA7_EFUSE_OD_MPU_OPP;
95 	}
96 
97 	return calculated_efuse;
98 }
99 
100 static unsigned long omap3_efuse_xlate(struct ti_cpufreq_data *opp_data,
101 				      unsigned long efuse)
102 {
103 	/* OPP enable bit ("Speed Binned") */
104 	return BIT(efuse);
105 }
106 
107 static struct ti_cpufreq_soc_data am3x_soc_data = {
108 	.efuse_xlate = amx3_efuse_xlate,
109 	.efuse_fallback = AM33XX_800M_ARM_MPU_MAX_FREQ,
110 	.efuse_offset = 0x07fc,
111 	.efuse_mask = 0x1fff,
112 	.rev_offset = 0x600,
113 	.multi_regulator = false,
114 };
115 
116 static struct ti_cpufreq_soc_data am4x_soc_data = {
117 	.efuse_xlate = amx3_efuse_xlate,
118 	.efuse_fallback = AM43XX_600M_ARM_MPU_MAX_FREQ,
119 	.efuse_offset = 0x0610,
120 	.efuse_mask = 0x3f,
121 	.rev_offset = 0x600,
122 	.multi_regulator = false,
123 };
124 
125 static struct ti_cpufreq_soc_data dra7_soc_data = {
126 	.efuse_xlate = dra7_efuse_xlate,
127 	.efuse_offset = 0x020c,
128 	.efuse_mask = 0xf80000,
129 	.efuse_shift = 19,
130 	.rev_offset = 0x204,
131 	.multi_regulator = true,
132 };
133 
134 /*
135  * OMAP35x TRM (SPRUF98K):
136  *  CONTROL_IDCODE (0x4830 A204) describes Silicon revisions.
137  *  Control OMAP Status Register 15:0 (Address 0x4800 244C)
138  *    to separate between omap3503, omap3515, omap3525, omap3530
139  *    and feature presence.
140  *    There are encodings for versions limited to 400/266MHz
141  *    but we ignore.
142  *    Not clear if this also holds for omap34xx.
143  *  some eFuse values e.g. CONTROL_FUSE_OPP1_VDD1
144  *    are stored in the SYSCON register range
145  *  Register 0x4830A20C [ProdID.SKUID] [0:3]
146  *    0x0 for normal 600/430MHz device.
147  *    0x8 for 720/520MHz device.
148  *    Not clear what omap34xx value is.
149  */
150 
151 static struct ti_cpufreq_soc_data omap34xx_soc_data = {
152 	.efuse_xlate = omap3_efuse_xlate,
153 	.efuse_offset = OMAP34xx_ProdID_SKUID - OMAP3_SYSCON_BASE,
154 	.efuse_shift = 3,
155 	.efuse_mask = BIT(3),
156 	.rev_offset = OMAP3_CONTROL_IDCODE - OMAP3_SYSCON_BASE,
157 	.multi_regulator = false,
158 };
159 
160 /*
161  * AM/DM37x TRM (SPRUGN4M)
162  *  CONTROL_IDCODE (0x4830 A204) describes Silicon revisions.
163  *  Control Device Status Register 15:0 (Address 0x4800 244C)
164  *    to separate between am3703, am3715, dm3725, dm3730
165  *    and feature presence.
166  *   Speed Binned = Bit 9
167  *     0 800/600 MHz
168  *     1 1000/800 MHz
169  *  some eFuse values e.g. CONTROL_FUSE_OPP 1G_VDD1
170  *    are stored in the SYSCON register range.
171  *  There is no 0x4830A20C [ProdID.SKUID] register (exists but
172  *    seems to always read as 0).
173  */
174 
175 static const char * const omap3_reg_names[] = {"cpu0", "vbb", NULL};
176 
177 static struct ti_cpufreq_soc_data omap36xx_soc_data = {
178 	.reg_names = omap3_reg_names,
179 	.efuse_xlate = omap3_efuse_xlate,
180 	.efuse_offset = OMAP3_CONTROL_DEVICE_STATUS - OMAP3_SYSCON_BASE,
181 	.efuse_shift = 9,
182 	.efuse_mask = BIT(9),
183 	.rev_offset = OMAP3_CONTROL_IDCODE - OMAP3_SYSCON_BASE,
184 	.multi_regulator = true,
185 };
186 
187 /*
188  * AM3517 is quite similar to AM/DM37x except that it has no
189  * high speed grade eFuse and no abb ldo
190  */
191 
192 static struct ti_cpufreq_soc_data am3517_soc_data = {
193 	.efuse_xlate = omap3_efuse_xlate,
194 	.efuse_offset = OMAP3_CONTROL_DEVICE_STATUS - OMAP3_SYSCON_BASE,
195 	.efuse_shift = 0,
196 	.efuse_mask = 0,
197 	.rev_offset = OMAP3_CONTROL_IDCODE - OMAP3_SYSCON_BASE,
198 	.multi_regulator = false,
199 };
200 
201 
202 /**
203  * ti_cpufreq_get_efuse() - Parse and return efuse value present on SoC
204  * @opp_data: pointer to ti_cpufreq_data context
205  * @efuse_value: Set to the value parsed from efuse
206  *
207  * Returns error code if efuse not read properly.
208  */
209 static int ti_cpufreq_get_efuse(struct ti_cpufreq_data *opp_data,
210 				u32 *efuse_value)
211 {
212 	struct device *dev = opp_data->cpu_dev;
213 	u32 efuse;
214 	int ret;
215 
216 	ret = regmap_read(opp_data->syscon, opp_data->soc_data->efuse_offset,
217 			  &efuse);
218 	if (ret == -EIO) {
219 		/* not a syscon register! */
220 		void __iomem *regs = ioremap(OMAP3_SYSCON_BASE +
221 				opp_data->soc_data->efuse_offset, 4);
222 
223 		if (!regs)
224 			return -ENOMEM;
225 		efuse = readl(regs);
226 		iounmap(regs);
227 		}
228 	else if (ret) {
229 		dev_err(dev,
230 			"Failed to read the efuse value from syscon: %d\n",
231 			ret);
232 		return ret;
233 	}
234 
235 	efuse = (efuse & opp_data->soc_data->efuse_mask);
236 	efuse >>= opp_data->soc_data->efuse_shift;
237 
238 	*efuse_value = opp_data->soc_data->efuse_xlate(opp_data, efuse);
239 
240 	return 0;
241 }
242 
243 /**
244  * ti_cpufreq_get_rev() - Parse and return rev value present on SoC
245  * @opp_data: pointer to ti_cpufreq_data context
246  * @revision_value: Set to the value parsed from revision register
247  *
248  * Returns error code if revision not read properly.
249  */
250 static int ti_cpufreq_get_rev(struct ti_cpufreq_data *opp_data,
251 			      u32 *revision_value)
252 {
253 	struct device *dev = opp_data->cpu_dev;
254 	u32 revision;
255 	int ret;
256 
257 	ret = regmap_read(opp_data->syscon, opp_data->soc_data->rev_offset,
258 			  &revision);
259 	if (ret == -EIO) {
260 		/* not a syscon register! */
261 		void __iomem *regs = ioremap(OMAP3_SYSCON_BASE +
262 				opp_data->soc_data->rev_offset, 4);
263 
264 		if (!regs)
265 			return -ENOMEM;
266 		revision = readl(regs);
267 		iounmap(regs);
268 		}
269 	else if (ret) {
270 		dev_err(dev,
271 			"Failed to read the revision number from syscon: %d\n",
272 			ret);
273 		return ret;
274 	}
275 
276 	*revision_value = BIT((revision >> REVISION_SHIFT) & REVISION_MASK);
277 
278 	return 0;
279 }
280 
281 static int ti_cpufreq_setup_syscon_register(struct ti_cpufreq_data *opp_data)
282 {
283 	struct device *dev = opp_data->cpu_dev;
284 	struct device_node *np = opp_data->opp_node;
285 
286 	opp_data->syscon = syscon_regmap_lookup_by_phandle(np,
287 							"syscon");
288 	if (IS_ERR(opp_data->syscon)) {
289 		dev_err(dev,
290 			"\"syscon\" is missing, cannot use OPPv2 table.\n");
291 		return PTR_ERR(opp_data->syscon);
292 	}
293 
294 	return 0;
295 }
296 
297 static const struct of_device_id ti_cpufreq_of_match[] = {
298 	{ .compatible = "ti,am33xx", .data = &am3x_soc_data, },
299 	{ .compatible = "ti,am3517", .data = &am3517_soc_data, },
300 	{ .compatible = "ti,am43", .data = &am4x_soc_data, },
301 	{ .compatible = "ti,dra7", .data = &dra7_soc_data },
302 	{ .compatible = "ti,omap34xx", .data = &omap34xx_soc_data, },
303 	{ .compatible = "ti,omap36xx", .data = &omap36xx_soc_data, },
304 	/* legacy */
305 	{ .compatible = "ti,omap3430", .data = &omap34xx_soc_data, },
306 	{ .compatible = "ti,omap3630", .data = &omap36xx_soc_data, },
307 	{},
308 };
309 
310 static const struct of_device_id *ti_cpufreq_match_node(void)
311 {
312 	struct device_node *np;
313 	const struct of_device_id *match;
314 
315 	np = of_find_node_by_path("/");
316 	match = of_match_node(ti_cpufreq_of_match, np);
317 	of_node_put(np);
318 
319 	return match;
320 }
321 
322 static int ti_cpufreq_probe(struct platform_device *pdev)
323 {
324 	u32 version[VERSION_COUNT];
325 	const struct of_device_id *match;
326 	struct ti_cpufreq_data *opp_data;
327 	const char * const default_reg_names[] = {"vdd", "vbb", NULL};
328 	int ret;
329 	struct dev_pm_opp_config config = {
330 		.supported_hw = version,
331 		.supported_hw_count = ARRAY_SIZE(version),
332 	};
333 
334 	match = dev_get_platdata(&pdev->dev);
335 	if (!match)
336 		return -ENODEV;
337 
338 	opp_data = devm_kzalloc(&pdev->dev, sizeof(*opp_data), GFP_KERNEL);
339 	if (!opp_data)
340 		return -ENOMEM;
341 
342 	opp_data->soc_data = match->data;
343 
344 	opp_data->cpu_dev = get_cpu_device(0);
345 	if (!opp_data->cpu_dev) {
346 		pr_err("%s: Failed to get device for CPU0\n", __func__);
347 		return -ENODEV;
348 	}
349 
350 	opp_data->opp_node = dev_pm_opp_of_get_opp_desc_node(opp_data->cpu_dev);
351 	if (!opp_data->opp_node) {
352 		dev_info(opp_data->cpu_dev,
353 			 "OPP-v2 not supported, cpufreq-dt will attempt to use legacy tables.\n");
354 		goto register_cpufreq_dt;
355 	}
356 
357 	ret = ti_cpufreq_setup_syscon_register(opp_data);
358 	if (ret)
359 		goto fail_put_node;
360 
361 	/*
362 	 * OPPs determine whether or not they are supported based on
363 	 * two metrics:
364 	 *	0 - SoC Revision
365 	 *	1 - eFuse value
366 	 */
367 	ret = ti_cpufreq_get_rev(opp_data, &version[0]);
368 	if (ret)
369 		goto fail_put_node;
370 
371 	ret = ti_cpufreq_get_efuse(opp_data, &version[1]);
372 	if (ret)
373 		goto fail_put_node;
374 
375 	if (opp_data->soc_data->multi_regulator) {
376 		if (opp_data->soc_data->reg_names)
377 			config.regulator_names = opp_data->soc_data->reg_names;
378 		else
379 			config.regulator_names = default_reg_names;
380 	}
381 
382 	ret = dev_pm_opp_set_config(opp_data->cpu_dev, &config);
383 	if (ret < 0) {
384 		dev_err(opp_data->cpu_dev, "Failed to set OPP config\n");
385 		goto fail_put_node;
386 	}
387 
388 	of_node_put(opp_data->opp_node);
389 
390 register_cpufreq_dt:
391 	platform_device_register_simple("cpufreq-dt", -1, NULL, 0);
392 
393 	return 0;
394 
395 fail_put_node:
396 	of_node_put(opp_data->opp_node);
397 
398 	return ret;
399 }
400 
401 static int __init ti_cpufreq_init(void)
402 {
403 	const struct of_device_id *match;
404 
405 	/* Check to ensure we are on a compatible platform */
406 	match = ti_cpufreq_match_node();
407 	if (match)
408 		platform_device_register_data(NULL, "ti-cpufreq", -1, match,
409 					      sizeof(*match));
410 
411 	return 0;
412 }
413 module_init(ti_cpufreq_init);
414 
415 static struct platform_driver ti_cpufreq_driver = {
416 	.probe = ti_cpufreq_probe,
417 	.driver = {
418 		.name = "ti-cpufreq",
419 	},
420 };
421 builtin_platform_driver(ti_cpufreq_driver);
422 
423 MODULE_DESCRIPTION("TI CPUFreq/OPP hw-supported driver");
424 MODULE_AUTHOR("Dave Gerlach <d-gerlach@ti.com>");
425 MODULE_LICENSE("GPL v2");
426