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