xref: /openbmc/linux/drivers/cpufreq/ti-cpufreq.c (revision 9a6b55ac)
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 DRA7_EFUSE_HAS_ALL_MPU_OPP		23
29 
30 #define DRA7_EFUSE_NOM_MPU_OPP			BIT(0)
31 #define DRA7_EFUSE_OD_MPU_OPP			BIT(1)
32 #define DRA7_EFUSE_HIGH_MPU_OPP			BIT(2)
33 
34 #define OMAP3_CONTROL_DEVICE_STATUS		0x4800244C
35 #define OMAP3_CONTROL_IDCODE			0x4830A204
36 #define OMAP34xx_ProdID_SKUID			0x4830A20C
37 #define OMAP3_SYSCON_BASE	(0x48000000 + 0x2000 + 0x270)
38 
39 #define VERSION_COUNT				2
40 
41 struct ti_cpufreq_data;
42 
43 struct ti_cpufreq_soc_data {
44 	const char * const *reg_names;
45 	unsigned long (*efuse_xlate)(struct ti_cpufreq_data *opp_data,
46 				     unsigned long efuse);
47 	unsigned long efuse_fallback;
48 	unsigned long efuse_offset;
49 	unsigned long efuse_mask;
50 	unsigned long efuse_shift;
51 	unsigned long rev_offset;
52 	bool multi_regulator;
53 };
54 
55 struct ti_cpufreq_data {
56 	struct device *cpu_dev;
57 	struct device_node *opp_node;
58 	struct regmap *syscon;
59 	const struct ti_cpufreq_soc_data *soc_data;
60 	struct opp_table *opp_table;
61 };
62 
63 static unsigned long amx3_efuse_xlate(struct ti_cpufreq_data *opp_data,
64 				      unsigned long efuse)
65 {
66 	if (!efuse)
67 		efuse = opp_data->soc_data->efuse_fallback;
68 	/* AM335x and AM437x use "OPP disable" bits, so invert */
69 	return ~efuse;
70 }
71 
72 static unsigned long dra7_efuse_xlate(struct ti_cpufreq_data *opp_data,
73 				      unsigned long efuse)
74 {
75 	unsigned long calculated_efuse = DRA7_EFUSE_NOM_MPU_OPP;
76 
77 	/*
78 	 * The efuse on dra7 and am57 parts contains a specific
79 	 * value indicating the highest available OPP.
80 	 */
81 
82 	switch (efuse) {
83 	case DRA7_EFUSE_HAS_ALL_MPU_OPP:
84 	case DRA7_EFUSE_HAS_HIGH_MPU_OPP:
85 		calculated_efuse |= DRA7_EFUSE_HIGH_MPU_OPP;
86 		/* Fall through */
87 	case DRA7_EFUSE_HAS_OD_MPU_OPP:
88 		calculated_efuse |= DRA7_EFUSE_OD_MPU_OPP;
89 	}
90 
91 	return calculated_efuse;
92 }
93 
94 static unsigned long omap3_efuse_xlate(struct ti_cpufreq_data *opp_data,
95 				      unsigned long efuse)
96 {
97 	/* OPP enable bit ("Speed Binned") */
98 	return BIT(efuse);
99 }
100 
101 static struct ti_cpufreq_soc_data am3x_soc_data = {
102 	.efuse_xlate = amx3_efuse_xlate,
103 	.efuse_fallback = AM33XX_800M_ARM_MPU_MAX_FREQ,
104 	.efuse_offset = 0x07fc,
105 	.efuse_mask = 0x1fff,
106 	.rev_offset = 0x600,
107 	.multi_regulator = false,
108 };
109 
110 static struct ti_cpufreq_soc_data am4x_soc_data = {
111 	.efuse_xlate = amx3_efuse_xlate,
112 	.efuse_fallback = AM43XX_600M_ARM_MPU_MAX_FREQ,
113 	.efuse_offset = 0x0610,
114 	.efuse_mask = 0x3f,
115 	.rev_offset = 0x600,
116 	.multi_regulator = false,
117 };
118 
119 static struct ti_cpufreq_soc_data dra7_soc_data = {
120 	.efuse_xlate = dra7_efuse_xlate,
121 	.efuse_offset = 0x020c,
122 	.efuse_mask = 0xf80000,
123 	.efuse_shift = 19,
124 	.rev_offset = 0x204,
125 	.multi_regulator = true,
126 };
127 
128 /*
129  * OMAP35x TRM (SPRUF98K):
130  *  CONTROL_IDCODE (0x4830 A204) describes Silicon revisions.
131  *  Control OMAP Status Register 15:0 (Address 0x4800 244C)
132  *    to separate between omap3503, omap3515, omap3525, omap3530
133  *    and feature presence.
134  *    There are encodings for versions limited to 400/266MHz
135  *    but we ignore.
136  *    Not clear if this also holds for omap34xx.
137  *  some eFuse values e.g. CONTROL_FUSE_OPP1_VDD1
138  *    are stored in the SYSCON register range
139  *  Register 0x4830A20C [ProdID.SKUID] [0:3]
140  *    0x0 for normal 600/430MHz device.
141  *    0x8 for 720/520MHz device.
142  *    Not clear what omap34xx value is.
143  */
144 
145 static struct ti_cpufreq_soc_data omap34xx_soc_data = {
146 	.efuse_xlate = omap3_efuse_xlate,
147 	.efuse_offset = OMAP34xx_ProdID_SKUID - OMAP3_SYSCON_BASE,
148 	.efuse_shift = 3,
149 	.efuse_mask = BIT(3),
150 	.rev_offset = OMAP3_CONTROL_IDCODE - OMAP3_SYSCON_BASE,
151 	.multi_regulator = false,
152 };
153 
154 /*
155  * AM/DM37x TRM (SPRUGN4M)
156  *  CONTROL_IDCODE (0x4830 A204) describes Silicon revisions.
157  *  Control Device Status Register 15:0 (Address 0x4800 244C)
158  *    to separate between am3703, am3715, dm3725, dm3730
159  *    and feature presence.
160  *   Speed Binned = Bit 9
161  *     0 800/600 MHz
162  *     1 1000/800 MHz
163  *  some eFuse values e.g. CONTROL_FUSE_OPP 1G_VDD1
164  *    are stored in the SYSCON register range.
165  *  There is no 0x4830A20C [ProdID.SKUID] register (exists but
166  *    seems to always read as 0).
167  */
168 
169 static const char * const omap3_reg_names[] = {"cpu0", "vbb"};
170 
171 static struct ti_cpufreq_soc_data omap36xx_soc_data = {
172 	.reg_names = omap3_reg_names,
173 	.efuse_xlate = omap3_efuse_xlate,
174 	.efuse_offset = OMAP3_CONTROL_DEVICE_STATUS - OMAP3_SYSCON_BASE,
175 	.efuse_shift = 9,
176 	.efuse_mask = BIT(9),
177 	.rev_offset = OMAP3_CONTROL_IDCODE - OMAP3_SYSCON_BASE,
178 	.multi_regulator = true,
179 };
180 
181 /*
182  * AM3517 is quite similar to AM/DM37x except that it has no
183  * high speed grade eFuse and no abb ldo
184  */
185 
186 static struct ti_cpufreq_soc_data am3517_soc_data = {
187 	.efuse_xlate = omap3_efuse_xlate,
188 	.efuse_offset = OMAP3_CONTROL_DEVICE_STATUS - OMAP3_SYSCON_BASE,
189 	.efuse_shift = 0,
190 	.efuse_mask = 0,
191 	.rev_offset = OMAP3_CONTROL_IDCODE - OMAP3_SYSCON_BASE,
192 	.multi_regulator = false,
193 };
194 
195 
196 /**
197  * ti_cpufreq_get_efuse() - Parse and return efuse value present on SoC
198  * @opp_data: pointer to ti_cpufreq_data context
199  * @efuse_value: Set to the value parsed from efuse
200  *
201  * Returns error code if efuse not read properly.
202  */
203 static int ti_cpufreq_get_efuse(struct ti_cpufreq_data *opp_data,
204 				u32 *efuse_value)
205 {
206 	struct device *dev = opp_data->cpu_dev;
207 	u32 efuse;
208 	int ret;
209 
210 	ret = regmap_read(opp_data->syscon, opp_data->soc_data->efuse_offset,
211 			  &efuse);
212 	if (ret == -EIO) {
213 		/* not a syscon register! */
214 		void __iomem *regs = ioremap(OMAP3_SYSCON_BASE +
215 				opp_data->soc_data->efuse_offset, 4);
216 
217 		if (!regs)
218 			return -ENOMEM;
219 		efuse = readl(regs);
220 		iounmap(regs);
221 		}
222 	else if (ret) {
223 		dev_err(dev,
224 			"Failed to read the efuse value from syscon: %d\n",
225 			ret);
226 		return ret;
227 	}
228 
229 	efuse = (efuse & opp_data->soc_data->efuse_mask);
230 	efuse >>= opp_data->soc_data->efuse_shift;
231 
232 	*efuse_value = opp_data->soc_data->efuse_xlate(opp_data, efuse);
233 
234 	return 0;
235 }
236 
237 /**
238  * ti_cpufreq_get_rev() - Parse and return rev value present on SoC
239  * @opp_data: pointer to ti_cpufreq_data context
240  * @revision_value: Set to the value parsed from revision register
241  *
242  * Returns error code if revision not read properly.
243  */
244 static int ti_cpufreq_get_rev(struct ti_cpufreq_data *opp_data,
245 			      u32 *revision_value)
246 {
247 	struct device *dev = opp_data->cpu_dev;
248 	u32 revision;
249 	int ret;
250 
251 	ret = regmap_read(opp_data->syscon, opp_data->soc_data->rev_offset,
252 			  &revision);
253 	if (ret == -EIO) {
254 		/* not a syscon register! */
255 		void __iomem *regs = ioremap(OMAP3_SYSCON_BASE +
256 				opp_data->soc_data->rev_offset, 4);
257 
258 		if (!regs)
259 			return -ENOMEM;
260 		revision = readl(regs);
261 		iounmap(regs);
262 		}
263 	else if (ret) {
264 		dev_err(dev,
265 			"Failed to read the revision number from syscon: %d\n",
266 			ret);
267 		return ret;
268 	}
269 
270 	*revision_value = BIT((revision >> REVISION_SHIFT) & REVISION_MASK);
271 
272 	return 0;
273 }
274 
275 static int ti_cpufreq_setup_syscon_register(struct ti_cpufreq_data *opp_data)
276 {
277 	struct device *dev = opp_data->cpu_dev;
278 	struct device_node *np = opp_data->opp_node;
279 
280 	opp_data->syscon = syscon_regmap_lookup_by_phandle(np,
281 							"syscon");
282 	if (IS_ERR(opp_data->syscon)) {
283 		dev_err(dev,
284 			"\"syscon\" is missing, cannot use OPPv2 table.\n");
285 		return PTR_ERR(opp_data->syscon);
286 	}
287 
288 	return 0;
289 }
290 
291 static const struct of_device_id ti_cpufreq_of_match[] = {
292 	{ .compatible = "ti,am33xx", .data = &am3x_soc_data, },
293 	{ .compatible = "ti,am3517", .data = &am3517_soc_data, },
294 	{ .compatible = "ti,am43", .data = &am4x_soc_data, },
295 	{ .compatible = "ti,dra7", .data = &dra7_soc_data },
296 	{ .compatible = "ti,omap34xx", .data = &omap34xx_soc_data, },
297 	{ .compatible = "ti,omap36xx", .data = &omap36xx_soc_data, },
298 	/* legacy */
299 	{ .compatible = "ti,omap3430", .data = &omap34xx_soc_data, },
300 	{ .compatible = "ti,omap3630", .data = &omap36xx_soc_data, },
301 	{},
302 };
303 
304 static const struct of_device_id *ti_cpufreq_match_node(void)
305 {
306 	struct device_node *np;
307 	const struct of_device_id *match;
308 
309 	np = of_find_node_by_path("/");
310 	match = of_match_node(ti_cpufreq_of_match, np);
311 	of_node_put(np);
312 
313 	return match;
314 }
315 
316 static int ti_cpufreq_probe(struct platform_device *pdev)
317 {
318 	u32 version[VERSION_COUNT];
319 	const struct of_device_id *match;
320 	struct opp_table *ti_opp_table;
321 	struct ti_cpufreq_data *opp_data;
322 	const char * const default_reg_names[] = {"vdd", "vbb"};
323 	int ret;
324 
325 	match = dev_get_platdata(&pdev->dev);
326 	if (!match)
327 		return -ENODEV;
328 
329 	opp_data = devm_kzalloc(&pdev->dev, sizeof(*opp_data), GFP_KERNEL);
330 	if (!opp_data)
331 		return -ENOMEM;
332 
333 	opp_data->soc_data = match->data;
334 
335 	opp_data->cpu_dev = get_cpu_device(0);
336 	if (!opp_data->cpu_dev) {
337 		pr_err("%s: Failed to get device for CPU0\n", __func__);
338 		return -ENODEV;
339 	}
340 
341 	opp_data->opp_node = dev_pm_opp_of_get_opp_desc_node(opp_data->cpu_dev);
342 	if (!opp_data->opp_node) {
343 		dev_info(opp_data->cpu_dev,
344 			 "OPP-v2 not supported, cpufreq-dt will attempt to use legacy tables.\n");
345 		goto register_cpufreq_dt;
346 	}
347 
348 	ret = ti_cpufreq_setup_syscon_register(opp_data);
349 	if (ret)
350 		goto fail_put_node;
351 
352 	/*
353 	 * OPPs determine whether or not they are supported based on
354 	 * two metrics:
355 	 *	0 - SoC Revision
356 	 *	1 - eFuse value
357 	 */
358 	ret = ti_cpufreq_get_rev(opp_data, &version[0]);
359 	if (ret)
360 		goto fail_put_node;
361 
362 	ret = ti_cpufreq_get_efuse(opp_data, &version[1]);
363 	if (ret)
364 		goto fail_put_node;
365 
366 	ti_opp_table = dev_pm_opp_set_supported_hw(opp_data->cpu_dev,
367 						   version, VERSION_COUNT);
368 	if (IS_ERR(ti_opp_table)) {
369 		dev_err(opp_data->cpu_dev,
370 			"Failed to set supported hardware\n");
371 		ret = PTR_ERR(ti_opp_table);
372 		goto fail_put_node;
373 	}
374 
375 	opp_data->opp_table = ti_opp_table;
376 
377 	if (opp_data->soc_data->multi_regulator) {
378 		const char * const *reg_names = default_reg_names;
379 
380 		if (opp_data->soc_data->reg_names)
381 			reg_names = opp_data->soc_data->reg_names;
382 		ti_opp_table = dev_pm_opp_set_regulators(opp_data->cpu_dev,
383 							 reg_names,
384 							 ARRAY_SIZE(default_reg_names));
385 		if (IS_ERR(ti_opp_table)) {
386 			dev_pm_opp_put_supported_hw(opp_data->opp_table);
387 			ret =  PTR_ERR(ti_opp_table);
388 			goto fail_put_node;
389 		}
390 	}
391 
392 	of_node_put(opp_data->opp_node);
393 register_cpufreq_dt:
394 	platform_device_register_simple("cpufreq-dt", -1, NULL, 0);
395 
396 	return 0;
397 
398 fail_put_node:
399 	of_node_put(opp_data->opp_node);
400 
401 	return ret;
402 }
403 
404 static int ti_cpufreq_init(void)
405 {
406 	const struct of_device_id *match;
407 
408 	/* Check to ensure we are on a compatible platform */
409 	match = ti_cpufreq_match_node();
410 	if (match)
411 		platform_device_register_data(NULL, "ti-cpufreq", -1, match,
412 					      sizeof(*match));
413 
414 	return 0;
415 }
416 module_init(ti_cpufreq_init);
417 
418 static struct platform_driver ti_cpufreq_driver = {
419 	.probe = ti_cpufreq_probe,
420 	.driver = {
421 		.name = "ti-cpufreq",
422 	},
423 };
424 builtin_platform_driver(ti_cpufreq_driver);
425 
426 MODULE_DESCRIPTION("TI CPUFreq/OPP hw-supported driver");
427 MODULE_AUTHOR("Dave Gerlach <d-gerlach@ti.com>");
428 MODULE_LICENSE("GPL v2");
429