xref: /openbmc/linux/drivers/cpufreq/ti-cpufreq.c (revision b737eecd)
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 	struct opp_table *opp_table;
64 };
65 
66 static unsigned long amx3_efuse_xlate(struct ti_cpufreq_data *opp_data,
67 				      unsigned long efuse)
68 {
69 	if (!efuse)
70 		efuse = opp_data->soc_data->efuse_fallback;
71 	/* AM335x and AM437x use "OPP disable" bits, so invert */
72 	return ~efuse;
73 }
74 
75 static unsigned long dra7_efuse_xlate(struct ti_cpufreq_data *opp_data,
76 				      unsigned long efuse)
77 {
78 	unsigned long calculated_efuse = DRA7_EFUSE_NOM_MPU_OPP;
79 
80 	/*
81 	 * The efuse on dra7 and am57 parts contains a specific
82 	 * value indicating the highest available OPP.
83 	 */
84 
85 	switch (efuse) {
86 	case DRA76_EFUSE_HAS_PLUS_MPU_OPP:
87 	case DRA76_EFUSE_HAS_ALL_MPU_OPP:
88 		calculated_efuse |= DRA76_EFUSE_PLUS_MPU_OPP;
89 		fallthrough;
90 	case DRA7_EFUSE_HAS_ALL_MPU_OPP:
91 	case DRA7_EFUSE_HAS_HIGH_MPU_OPP:
92 		calculated_efuse |= DRA7_EFUSE_HIGH_MPU_OPP;
93 		fallthrough;
94 	case DRA7_EFUSE_HAS_OD_MPU_OPP:
95 		calculated_efuse |= DRA7_EFUSE_OD_MPU_OPP;
96 	}
97 
98 	return calculated_efuse;
99 }
100 
101 static unsigned long omap3_efuse_xlate(struct ti_cpufreq_data *opp_data,
102 				      unsigned long efuse)
103 {
104 	/* OPP enable bit ("Speed Binned") */
105 	return BIT(efuse);
106 }
107 
108 static struct ti_cpufreq_soc_data am3x_soc_data = {
109 	.efuse_xlate = amx3_efuse_xlate,
110 	.efuse_fallback = AM33XX_800M_ARM_MPU_MAX_FREQ,
111 	.efuse_offset = 0x07fc,
112 	.efuse_mask = 0x1fff,
113 	.rev_offset = 0x600,
114 	.multi_regulator = false,
115 };
116 
117 static struct ti_cpufreq_soc_data am4x_soc_data = {
118 	.efuse_xlate = amx3_efuse_xlate,
119 	.efuse_fallback = AM43XX_600M_ARM_MPU_MAX_FREQ,
120 	.efuse_offset = 0x0610,
121 	.efuse_mask = 0x3f,
122 	.rev_offset = 0x600,
123 	.multi_regulator = false,
124 };
125 
126 static struct ti_cpufreq_soc_data dra7_soc_data = {
127 	.efuse_xlate = dra7_efuse_xlate,
128 	.efuse_offset = 0x020c,
129 	.efuse_mask = 0xf80000,
130 	.efuse_shift = 19,
131 	.rev_offset = 0x204,
132 	.multi_regulator = true,
133 };
134 
135 /*
136  * OMAP35x TRM (SPRUF98K):
137  *  CONTROL_IDCODE (0x4830 A204) describes Silicon revisions.
138  *  Control OMAP Status Register 15:0 (Address 0x4800 244C)
139  *    to separate between omap3503, omap3515, omap3525, omap3530
140  *    and feature presence.
141  *    There are encodings for versions limited to 400/266MHz
142  *    but we ignore.
143  *    Not clear if this also holds for omap34xx.
144  *  some eFuse values e.g. CONTROL_FUSE_OPP1_VDD1
145  *    are stored in the SYSCON register range
146  *  Register 0x4830A20C [ProdID.SKUID] [0:3]
147  *    0x0 for normal 600/430MHz device.
148  *    0x8 for 720/520MHz device.
149  *    Not clear what omap34xx value is.
150  */
151 
152 static struct ti_cpufreq_soc_data omap34xx_soc_data = {
153 	.efuse_xlate = omap3_efuse_xlate,
154 	.efuse_offset = OMAP34xx_ProdID_SKUID - OMAP3_SYSCON_BASE,
155 	.efuse_shift = 3,
156 	.efuse_mask = BIT(3),
157 	.rev_offset = OMAP3_CONTROL_IDCODE - OMAP3_SYSCON_BASE,
158 	.multi_regulator = false,
159 };
160 
161 /*
162  * AM/DM37x TRM (SPRUGN4M)
163  *  CONTROL_IDCODE (0x4830 A204) describes Silicon revisions.
164  *  Control Device Status Register 15:0 (Address 0x4800 244C)
165  *    to separate between am3703, am3715, dm3725, dm3730
166  *    and feature presence.
167  *   Speed Binned = Bit 9
168  *     0 800/600 MHz
169  *     1 1000/800 MHz
170  *  some eFuse values e.g. CONTROL_FUSE_OPP 1G_VDD1
171  *    are stored in the SYSCON register range.
172  *  There is no 0x4830A20C [ProdID.SKUID] register (exists but
173  *    seems to always read as 0).
174  */
175 
176 static const char * const omap3_reg_names[] = {"cpu0", "vbb"};
177 
178 static struct ti_cpufreq_soc_data omap36xx_soc_data = {
179 	.reg_names = omap3_reg_names,
180 	.efuse_xlate = omap3_efuse_xlate,
181 	.efuse_offset = OMAP3_CONTROL_DEVICE_STATUS - OMAP3_SYSCON_BASE,
182 	.efuse_shift = 9,
183 	.efuse_mask = BIT(9),
184 	.rev_offset = OMAP3_CONTROL_IDCODE - OMAP3_SYSCON_BASE,
185 	.multi_regulator = true,
186 };
187 
188 /*
189  * AM3517 is quite similar to AM/DM37x except that it has no
190  * high speed grade eFuse and no abb ldo
191  */
192 
193 static struct ti_cpufreq_soc_data am3517_soc_data = {
194 	.efuse_xlate = omap3_efuse_xlate,
195 	.efuse_offset = OMAP3_CONTROL_DEVICE_STATUS - OMAP3_SYSCON_BASE,
196 	.efuse_shift = 0,
197 	.efuse_mask = 0,
198 	.rev_offset = OMAP3_CONTROL_IDCODE - OMAP3_SYSCON_BASE,
199 	.multi_regulator = false,
200 };
201 
202 
203 /**
204  * ti_cpufreq_get_efuse() - Parse and return efuse value present on SoC
205  * @opp_data: pointer to ti_cpufreq_data context
206  * @efuse_value: Set to the value parsed from efuse
207  *
208  * Returns error code if efuse not read properly.
209  */
210 static int ti_cpufreq_get_efuse(struct ti_cpufreq_data *opp_data,
211 				u32 *efuse_value)
212 {
213 	struct device *dev = opp_data->cpu_dev;
214 	u32 efuse;
215 	int ret;
216 
217 	ret = regmap_read(opp_data->syscon, opp_data->soc_data->efuse_offset,
218 			  &efuse);
219 	if (ret == -EIO) {
220 		/* not a syscon register! */
221 		void __iomem *regs = ioremap(OMAP3_SYSCON_BASE +
222 				opp_data->soc_data->efuse_offset, 4);
223 
224 		if (!regs)
225 			return -ENOMEM;
226 		efuse = readl(regs);
227 		iounmap(regs);
228 		}
229 	else if (ret) {
230 		dev_err(dev,
231 			"Failed to read the efuse value from syscon: %d\n",
232 			ret);
233 		return ret;
234 	}
235 
236 	efuse = (efuse & opp_data->soc_data->efuse_mask);
237 	efuse >>= opp_data->soc_data->efuse_shift;
238 
239 	*efuse_value = opp_data->soc_data->efuse_xlate(opp_data, efuse);
240 
241 	return 0;
242 }
243 
244 /**
245  * ti_cpufreq_get_rev() - Parse and return rev value present on SoC
246  * @opp_data: pointer to ti_cpufreq_data context
247  * @revision_value: Set to the value parsed from revision register
248  *
249  * Returns error code if revision not read properly.
250  */
251 static int ti_cpufreq_get_rev(struct ti_cpufreq_data *opp_data,
252 			      u32 *revision_value)
253 {
254 	struct device *dev = opp_data->cpu_dev;
255 	u32 revision;
256 	int ret;
257 
258 	ret = regmap_read(opp_data->syscon, opp_data->soc_data->rev_offset,
259 			  &revision);
260 	if (ret == -EIO) {
261 		/* not a syscon register! */
262 		void __iomem *regs = ioremap(OMAP3_SYSCON_BASE +
263 				opp_data->soc_data->rev_offset, 4);
264 
265 		if (!regs)
266 			return -ENOMEM;
267 		revision = readl(regs);
268 		iounmap(regs);
269 		}
270 	else if (ret) {
271 		dev_err(dev,
272 			"Failed to read the revision number from syscon: %d\n",
273 			ret);
274 		return ret;
275 	}
276 
277 	*revision_value = BIT((revision >> REVISION_SHIFT) & REVISION_MASK);
278 
279 	return 0;
280 }
281 
282 static int ti_cpufreq_setup_syscon_register(struct ti_cpufreq_data *opp_data)
283 {
284 	struct device *dev = opp_data->cpu_dev;
285 	struct device_node *np = opp_data->opp_node;
286 
287 	opp_data->syscon = syscon_regmap_lookup_by_phandle(np,
288 							"syscon");
289 	if (IS_ERR(opp_data->syscon)) {
290 		dev_err(dev,
291 			"\"syscon\" is missing, cannot use OPPv2 table.\n");
292 		return PTR_ERR(opp_data->syscon);
293 	}
294 
295 	return 0;
296 }
297 
298 static const struct of_device_id ti_cpufreq_of_match[] = {
299 	{ .compatible = "ti,am33xx", .data = &am3x_soc_data, },
300 	{ .compatible = "ti,am3517", .data = &am3517_soc_data, },
301 	{ .compatible = "ti,am43", .data = &am4x_soc_data, },
302 	{ .compatible = "ti,dra7", .data = &dra7_soc_data },
303 	{ .compatible = "ti,omap34xx", .data = &omap34xx_soc_data, },
304 	{ .compatible = "ti,omap36xx", .data = &omap36xx_soc_data, },
305 	/* legacy */
306 	{ .compatible = "ti,omap3430", .data = &omap34xx_soc_data, },
307 	{ .compatible = "ti,omap3630", .data = &omap36xx_soc_data, },
308 	{},
309 };
310 
311 static const struct of_device_id *ti_cpufreq_match_node(void)
312 {
313 	struct device_node *np;
314 	const struct of_device_id *match;
315 
316 	np = of_find_node_by_path("/");
317 	match = of_match_node(ti_cpufreq_of_match, np);
318 	of_node_put(np);
319 
320 	return match;
321 }
322 
323 static int ti_cpufreq_probe(struct platform_device *pdev)
324 {
325 	u32 version[VERSION_COUNT];
326 	const struct of_device_id *match;
327 	struct opp_table *ti_opp_table;
328 	struct ti_cpufreq_data *opp_data;
329 	const char * const default_reg_names[] = {"vdd", "vbb"};
330 	int ret;
331 
332 	match = dev_get_platdata(&pdev->dev);
333 	if (!match)
334 		return -ENODEV;
335 
336 	opp_data = devm_kzalloc(&pdev->dev, sizeof(*opp_data), GFP_KERNEL);
337 	if (!opp_data)
338 		return -ENOMEM;
339 
340 	opp_data->soc_data = match->data;
341 
342 	opp_data->cpu_dev = get_cpu_device(0);
343 	if (!opp_data->cpu_dev) {
344 		pr_err("%s: Failed to get device for CPU0\n", __func__);
345 		return -ENODEV;
346 	}
347 
348 	opp_data->opp_node = dev_pm_opp_of_get_opp_desc_node(opp_data->cpu_dev);
349 	if (!opp_data->opp_node) {
350 		dev_info(opp_data->cpu_dev,
351 			 "OPP-v2 not supported, cpufreq-dt will attempt to use legacy tables.\n");
352 		goto register_cpufreq_dt;
353 	}
354 
355 	ret = ti_cpufreq_setup_syscon_register(opp_data);
356 	if (ret)
357 		goto fail_put_node;
358 
359 	/*
360 	 * OPPs determine whether or not they are supported based on
361 	 * two metrics:
362 	 *	0 - SoC Revision
363 	 *	1 - eFuse value
364 	 */
365 	ret = ti_cpufreq_get_rev(opp_data, &version[0]);
366 	if (ret)
367 		goto fail_put_node;
368 
369 	ret = ti_cpufreq_get_efuse(opp_data, &version[1]);
370 	if (ret)
371 		goto fail_put_node;
372 
373 	ti_opp_table = dev_pm_opp_set_supported_hw(opp_data->cpu_dev,
374 						   version, VERSION_COUNT);
375 	if (IS_ERR(ti_opp_table)) {
376 		dev_err(opp_data->cpu_dev,
377 			"Failed to set supported hardware\n");
378 		ret = PTR_ERR(ti_opp_table);
379 		goto fail_put_node;
380 	}
381 
382 	opp_data->opp_table = ti_opp_table;
383 
384 	if (opp_data->soc_data->multi_regulator) {
385 		const char * const *reg_names = default_reg_names;
386 
387 		if (opp_data->soc_data->reg_names)
388 			reg_names = opp_data->soc_data->reg_names;
389 		ti_opp_table = dev_pm_opp_set_regulators(opp_data->cpu_dev,
390 							 reg_names,
391 							 ARRAY_SIZE(default_reg_names));
392 		if (IS_ERR(ti_opp_table)) {
393 			dev_pm_opp_put_supported_hw(opp_data->opp_table);
394 			ret =  PTR_ERR(ti_opp_table);
395 			goto fail_put_node;
396 		}
397 	}
398 
399 	of_node_put(opp_data->opp_node);
400 register_cpufreq_dt:
401 	platform_device_register_simple("cpufreq-dt", -1, NULL, 0);
402 
403 	return 0;
404 
405 fail_put_node:
406 	of_node_put(opp_data->opp_node);
407 
408 	return ret;
409 }
410 
411 static int ti_cpufreq_init(void)
412 {
413 	const struct of_device_id *match;
414 
415 	/* Check to ensure we are on a compatible platform */
416 	match = ti_cpufreq_match_node();
417 	if (match)
418 		platform_device_register_data(NULL, "ti-cpufreq", -1, match,
419 					      sizeof(*match));
420 
421 	return 0;
422 }
423 module_init(ti_cpufreq_init);
424 
425 static struct platform_driver ti_cpufreq_driver = {
426 	.probe = ti_cpufreq_probe,
427 	.driver = {
428 		.name = "ti-cpufreq",
429 	},
430 };
431 builtin_platform_driver(ti_cpufreq_driver);
432 
433 MODULE_DESCRIPTION("TI CPUFreq/OPP hw-supported driver");
434 MODULE_AUTHOR("Dave Gerlach <d-gerlach@ti.com>");
435 MODULE_LICENSE("GPL v2");
436