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 */
29struct 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 */
42struct 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
50static 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 */
59struct 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 */
77static 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	}
167out:
168	iounmap(base);
169out_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 */
178static 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 */
195static 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
220static 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 */
274static 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
328restore_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
348static const struct ti_opp_supply_of_data omap_generic_of_data = {
349};
350
351static 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
357static 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
363static 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};
370MODULE_DEVICE_TABLE(of, ti_opp_supply_of_match);
371
372static 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
406	return ret;
407}
408
409static struct platform_driver ti_opp_supply_driver = {
410	.probe = ti_opp_supply_probe,
411	.driver = {
412		   .name = "ti_opp_supply",
413		   .of_match_table = of_match_ptr(ti_opp_supply_of_match),
414		   },
415};
416module_platform_driver(ti_opp_supply_driver);
417
418MODULE_DESCRIPTION("Texas Instruments OMAP OPP Supply driver");
419MODULE_AUTHOR("Texas Instruments Inc.");
420MODULE_LICENSE("GPL v2");
421