xref: /openbmc/linux/drivers/opp/ti-opp-supply.c (revision 21dec022)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2016-2017 Texas Instruments Incorporated - https://www.ti.com/
4  *	Nishanth Menon <nm@ti.com>
5  *	Dave Gerlach <d-gerlach@ti.com>
6  *
7  * TI OPP supply driver that provides override into the regulator control
8  * for generic opp core to handle devices with ABB regulator and/or
9  * SmartReflex Class0.
10  */
11 #include <linux/clk.h>
12 #include <linux/cpufreq.h>
13 #include <linux/device.h>
14 #include <linux/io.h>
15 #include <linux/module.h>
16 #include <linux/notifier.h>
17 #include <linux/of_device.h>
18 #include <linux/of.h>
19 #include <linux/platform_device.h>
20 #include <linux/pm_opp.h>
21 #include <linux/regulator/consumer.h>
22 #include <linux/slab.h>
23 
24 /**
25  * struct ti_opp_supply_optimum_voltage_table - optimized voltage table
26  * @reference_uv:	reference voltage (usually Nominal voltage)
27  * @optimized_uv:	Optimized voltage from efuse
28  */
29 struct ti_opp_supply_optimum_voltage_table {
30 	unsigned int reference_uv;
31 	unsigned int optimized_uv;
32 };
33 
34 /**
35  * struct ti_opp_supply_data - OMAP specific opp supply data
36  * @vdd_table:	Optimized voltage mapping table
37  * @num_vdd_table: number of entries in vdd_table
38  * @vdd_absolute_max_voltage_uv: absolute maximum voltage in UV for the supply
39  * @old_supplies: Placeholder for supplies information for old OPP.
40  * @new_supplies: Placeholder for supplies information for new OPP.
41  */
42 struct ti_opp_supply_data {
43 	struct ti_opp_supply_optimum_voltage_table *vdd_table;
44 	u32 num_vdd_table;
45 	u32 vdd_absolute_max_voltage_uv;
46 	struct dev_pm_opp_supply old_supplies[2];
47 	struct dev_pm_opp_supply new_supplies[2];
48 };
49 
50 static struct ti_opp_supply_data opp_data;
51 
52 /**
53  * struct ti_opp_supply_of_data - device tree match data
54  * @flags:	specific type of opp supply
55  * @efuse_voltage_mask: mask required for efuse register representing voltage
56  * @efuse_voltage_uv: Are the efuse entries in micro-volts? if not, assume
57  *		milli-volts.
58  */
59 struct ti_opp_supply_of_data {
60 #define OPPDM_EFUSE_CLASS0_OPTIMIZED_VOLTAGE	BIT(1)
61 #define OPPDM_HAS_NO_ABB			BIT(2)
62 	const u8 flags;
63 	const u32 efuse_voltage_mask;
64 	const bool efuse_voltage_uv;
65 };
66 
67 /**
68  * _store_optimized_voltages() - store optimized voltages
69  * @dev:	ti opp supply device for which we need to store info
70  * @data:	data specific to the device
71  *
72  * Picks up efuse based optimized voltages for VDD unique per device and
73  * stores it in internal data structure for use during transition requests.
74  *
75  * Return: If successful, 0, else appropriate error value.
76  */
_store_optimized_voltages(struct device * dev,struct ti_opp_supply_data * data)77 static int _store_optimized_voltages(struct device *dev,
78 				     struct ti_opp_supply_data *data)
79 {
80 	void __iomem *base;
81 	struct property *prop;
82 	struct resource *res;
83 	const __be32 *val;
84 	int proplen, i;
85 	int ret = 0;
86 	struct ti_opp_supply_optimum_voltage_table *table;
87 	const struct ti_opp_supply_of_data *of_data = dev_get_drvdata(dev);
88 
89 	/* pick up Efuse based voltages */
90 	res = platform_get_resource(to_platform_device(dev), IORESOURCE_MEM, 0);
91 	if (!res) {
92 		dev_err(dev, "Unable to get IO resource\n");
93 		ret = -ENODEV;
94 		goto out_map;
95 	}
96 
97 	base = ioremap(res->start, resource_size(res));
98 	if (!base) {
99 		dev_err(dev, "Unable to map Efuse registers\n");
100 		ret = -ENOMEM;
101 		goto out_map;
102 	}
103 
104 	/* Fetch efuse-settings. */
105 	prop = of_find_property(dev->of_node, "ti,efuse-settings", NULL);
106 	if (!prop) {
107 		dev_err(dev, "No 'ti,efuse-settings' property found\n");
108 		ret = -EINVAL;
109 		goto out;
110 	}
111 
112 	proplen = prop->length / sizeof(int);
113 	data->num_vdd_table = proplen / 2;
114 	/* Verify for corrupted OPP entries in dt */
115 	if (data->num_vdd_table * 2 * sizeof(int) != prop->length) {
116 		dev_err(dev, "Invalid 'ti,efuse-settings'\n");
117 		ret = -EINVAL;
118 		goto out;
119 	}
120 
121 	ret = of_property_read_u32(dev->of_node, "ti,absolute-max-voltage-uv",
122 				   &data->vdd_absolute_max_voltage_uv);
123 	if (ret) {
124 		dev_err(dev, "ti,absolute-max-voltage-uv is missing\n");
125 		ret = -EINVAL;
126 		goto out;
127 	}
128 
129 	table = kcalloc(data->num_vdd_table, sizeof(*data->vdd_table),
130 			GFP_KERNEL);
131 	if (!table) {
132 		ret = -ENOMEM;
133 		goto out;
134 	}
135 	data->vdd_table = table;
136 
137 	val = prop->value;
138 	for (i = 0; i < data->num_vdd_table; i++, table++) {
139 		u32 efuse_offset;
140 		u32 tmp;
141 
142 		table->reference_uv = be32_to_cpup(val++);
143 		efuse_offset = be32_to_cpup(val++);
144 
145 		tmp = readl(base + efuse_offset);
146 		tmp &= of_data->efuse_voltage_mask;
147 		tmp >>= __ffs(of_data->efuse_voltage_mask);
148 
149 		table->optimized_uv = of_data->efuse_voltage_uv ? tmp :
150 					tmp * 1000;
151 
152 		dev_dbg(dev, "[%d] efuse=0x%08x volt_table=%d vset=%d\n",
153 			i, efuse_offset, table->reference_uv,
154 			table->optimized_uv);
155 
156 		/*
157 		 * Some older samples might not have optimized efuse
158 		 * Use reference voltage for those - just add debug message
159 		 * for them.
160 		 */
161 		if (!table->optimized_uv) {
162 			dev_dbg(dev, "[%d] efuse=0x%08x volt_table=%d:vset0\n",
163 				i, efuse_offset, table->reference_uv);
164 			table->optimized_uv = table->reference_uv;
165 		}
166 	}
167 out:
168 	iounmap(base);
169 out_map:
170 	return ret;
171 }
172 
173 /**
174  * _free_optimized_voltages() - free resources for optvoltages
175  * @dev:	device for which we need to free info
176  * @data:	data specific to the device
177  */
_free_optimized_voltages(struct device * dev,struct ti_opp_supply_data * data)178 static void _free_optimized_voltages(struct device *dev,
179 				     struct ti_opp_supply_data *data)
180 {
181 	kfree(data->vdd_table);
182 	data->vdd_table = NULL;
183 	data->num_vdd_table = 0;
184 }
185 
186 /**
187  * _get_optimal_vdd_voltage() - Finds optimal voltage for the supply
188  * @dev:	device for which we need to find info
189  * @data:	data specific to the device
190  * @reference_uv:	reference voltage (OPP voltage) for which we need value
191  *
192  * Return: if a match is found, return optimized voltage, else return
193  * reference_uv, also return reference_uv if no optimization is needed.
194  */
_get_optimal_vdd_voltage(struct device * dev,struct ti_opp_supply_data * data,int reference_uv)195 static int _get_optimal_vdd_voltage(struct device *dev,
196 				    struct ti_opp_supply_data *data,
197 				    int reference_uv)
198 {
199 	int i;
200 	struct ti_opp_supply_optimum_voltage_table *table;
201 
202 	if (!data->num_vdd_table)
203 		return reference_uv;
204 
205 	table = data->vdd_table;
206 	if (!table)
207 		return -EINVAL;
208 
209 	/* Find a exact match - this list is usually very small */
210 	for (i = 0; i < data->num_vdd_table; i++, table++)
211 		if (table->reference_uv == reference_uv)
212 			return table->optimized_uv;
213 
214 	/* IF things are screwed up, we'd make a mess on console.. ratelimit */
215 	dev_err_ratelimited(dev, "%s: Failed optimized voltage match for %d\n",
216 			    __func__, reference_uv);
217 	return reference_uv;
218 }
219 
_opp_set_voltage(struct device * dev,struct dev_pm_opp_supply * supply,int new_target_uv,struct regulator * reg,char * reg_name)220 static int _opp_set_voltage(struct device *dev,
221 			    struct dev_pm_opp_supply *supply,
222 			    int new_target_uv, struct regulator *reg,
223 			    char *reg_name)
224 {
225 	int ret;
226 	unsigned long vdd_uv, uv_max;
227 
228 	if (new_target_uv)
229 		vdd_uv = new_target_uv;
230 	else
231 		vdd_uv = supply->u_volt;
232 
233 	/*
234 	 * If we do have an absolute max voltage specified, then we should
235 	 * use that voltage instead to allow for cases where the voltage rails
236 	 * are ganged (example if we set the max for an opp as 1.12v, and
237 	 * the absolute max is 1.5v, for another rail to get 1.25v, it cannot
238 	 * be achieved if the regulator is constrainted to max of 1.12v, even
239 	 * if it can function at 1.25v
240 	 */
241 	if (opp_data.vdd_absolute_max_voltage_uv)
242 		uv_max = opp_data.vdd_absolute_max_voltage_uv;
243 	else
244 		uv_max = supply->u_volt_max;
245 
246 	if (vdd_uv > uv_max ||
247 	    vdd_uv < supply->u_volt_min ||
248 	    supply->u_volt_min > uv_max) {
249 		dev_warn(dev,
250 			 "Invalid range voltages [Min:%lu target:%lu Max:%lu]\n",
251 			 supply->u_volt_min, vdd_uv, uv_max);
252 		return -EINVAL;
253 	}
254 
255 	dev_dbg(dev, "%s scaling to %luuV[min %luuV max %luuV]\n", reg_name,
256 		vdd_uv, supply->u_volt_min,
257 		uv_max);
258 
259 	ret = regulator_set_voltage_triplet(reg,
260 					    supply->u_volt_min,
261 					    vdd_uv,
262 					    uv_max);
263 	if (ret) {
264 		dev_err(dev, "%s failed for %luuV[min %luuV max %luuV]\n",
265 			reg_name, vdd_uv, supply->u_volt_min,
266 			uv_max);
267 		return ret;
268 	}
269 
270 	return 0;
271 }
272 
273 /* Do the opp supply transition */
ti_opp_config_regulators(struct device * dev,struct dev_pm_opp * old_opp,struct dev_pm_opp * new_opp,struct regulator ** regulators,unsigned int count)274 static int ti_opp_config_regulators(struct device *dev,
275 			struct dev_pm_opp *old_opp, struct dev_pm_opp *new_opp,
276 			struct regulator **regulators, unsigned int count)
277 {
278 	struct dev_pm_opp_supply *old_supply_vdd = &opp_data.old_supplies[0];
279 	struct dev_pm_opp_supply *old_supply_vbb = &opp_data.old_supplies[1];
280 	struct dev_pm_opp_supply *new_supply_vdd = &opp_data.new_supplies[0];
281 	struct dev_pm_opp_supply *new_supply_vbb = &opp_data.new_supplies[1];
282 	struct regulator *vdd_reg = regulators[0];
283 	struct regulator *vbb_reg = regulators[1];
284 	unsigned long old_freq, freq;
285 	int vdd_uv;
286 	int ret;
287 
288 	/* We must have two regulators here */
289 	WARN_ON(count != 2);
290 
291 	/* Fetch supplies and freq information from OPP core */
292 	ret = dev_pm_opp_get_supplies(new_opp, opp_data.new_supplies);
293 	WARN_ON(ret);
294 
295 	old_freq = dev_pm_opp_get_freq(old_opp);
296 	freq = dev_pm_opp_get_freq(new_opp);
297 	WARN_ON(!old_freq || !freq);
298 
299 	vdd_uv = _get_optimal_vdd_voltage(dev, &opp_data,
300 					  new_supply_vdd->u_volt);
301 
302 	if (new_supply_vdd->u_volt_min < vdd_uv)
303 		new_supply_vdd->u_volt_min = vdd_uv;
304 
305 	/* Scaling up? Scale voltage before frequency */
306 	if (freq > old_freq) {
307 		ret = _opp_set_voltage(dev, new_supply_vdd, vdd_uv, vdd_reg,
308 				       "vdd");
309 		if (ret)
310 			goto restore_voltage;
311 
312 		ret = _opp_set_voltage(dev, new_supply_vbb, 0, vbb_reg, "vbb");
313 		if (ret)
314 			goto restore_voltage;
315 	} else {
316 		ret = _opp_set_voltage(dev, new_supply_vbb, 0, vbb_reg, "vbb");
317 		if (ret)
318 			goto restore_voltage;
319 
320 		ret = _opp_set_voltage(dev, new_supply_vdd, vdd_uv, vdd_reg,
321 				       "vdd");
322 		if (ret)
323 			goto restore_voltage;
324 	}
325 
326 	return 0;
327 
328 restore_voltage:
329 	/* Fetch old supplies information only if required */
330 	ret = dev_pm_opp_get_supplies(old_opp, opp_data.old_supplies);
331 	WARN_ON(ret);
332 
333 	/* This shouldn't harm even if the voltages weren't updated earlier */
334 	if (old_supply_vdd->u_volt) {
335 		ret = _opp_set_voltage(dev, old_supply_vbb, 0, vbb_reg, "vbb");
336 		if (ret)
337 			return ret;
338 
339 		ret = _opp_set_voltage(dev, old_supply_vdd, 0, vdd_reg,
340 				       "vdd");
341 		if (ret)
342 			return ret;
343 	}
344 
345 	return ret;
346 }
347 
348 static const struct ti_opp_supply_of_data omap_generic_of_data = {
349 };
350 
351 static const struct ti_opp_supply_of_data omap_omap5_of_data = {
352 	.flags = OPPDM_EFUSE_CLASS0_OPTIMIZED_VOLTAGE,
353 	.efuse_voltage_mask = 0xFFF,
354 	.efuse_voltage_uv = false,
355 };
356 
357 static const struct ti_opp_supply_of_data omap_omap5core_of_data = {
358 	.flags = OPPDM_EFUSE_CLASS0_OPTIMIZED_VOLTAGE | OPPDM_HAS_NO_ABB,
359 	.efuse_voltage_mask = 0xFFF,
360 	.efuse_voltage_uv = false,
361 };
362 
363 static const struct of_device_id ti_opp_supply_of_match[] = {
364 	{.compatible = "ti,omap-opp-supply", .data = &omap_generic_of_data},
365 	{.compatible = "ti,omap5-opp-supply", .data = &omap_omap5_of_data},
366 	{.compatible = "ti,omap5-core-opp-supply",
367 	 .data = &omap_omap5core_of_data},
368 	{},
369 };
370 MODULE_DEVICE_TABLE(of, ti_opp_supply_of_match);
371 
ti_opp_supply_probe(struct platform_device * pdev)372 static int ti_opp_supply_probe(struct platform_device *pdev)
373 {
374 	struct device *dev = &pdev->dev;
375 	struct device *cpu_dev = get_cpu_device(0);
376 	const struct of_device_id *match;
377 	const struct ti_opp_supply_of_data *of_data;
378 	int ret = 0;
379 
380 	match = of_match_device(ti_opp_supply_of_match, dev);
381 	if (!match) {
382 		/* We do not expect this to happen */
383 		dev_err(dev, "%s: Unable to match device\n", __func__);
384 		return -ENODEV;
385 	}
386 	if (!match->data) {
387 		/* Again, unlikely.. but mistakes do happen */
388 		dev_err(dev, "%s: Bad data in match\n", __func__);
389 		return -EINVAL;
390 	}
391 	of_data = match->data;
392 
393 	dev_set_drvdata(dev, (void *)of_data);
394 
395 	/* If we need optimized voltage */
396 	if (of_data->flags & OPPDM_EFUSE_CLASS0_OPTIMIZED_VOLTAGE) {
397 		ret = _store_optimized_voltages(dev, &opp_data);
398 		if (ret)
399 			return ret;
400 	}
401 
402 	ret = dev_pm_opp_set_config_regulators(cpu_dev, ti_opp_config_regulators);
403 	if (ret < 0) {
404 		_free_optimized_voltages(dev, &opp_data);
405 		return ret;
406 	}
407 
408 	return 0;
409 }
410 
411 static struct platform_driver ti_opp_supply_driver = {
412 	.probe = ti_opp_supply_probe,
413 	.driver = {
414 		   .name = "ti_opp_supply",
415 		   .of_match_table = of_match_ptr(ti_opp_supply_of_match),
416 		   },
417 };
418 module_platform_driver(ti_opp_supply_driver);
419 
420 MODULE_DESCRIPTION("Texas Instruments OMAP OPP Supply driver");
421 MODULE_AUTHOR("Texas Instruments Inc.");
422 MODULE_LICENSE("GPL v2");
423