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 */
40 struct ti_opp_supply_data {
41 struct ti_opp_supply_optimum_voltage_table *vdd_table;
42 u32 num_vdd_table;
43 u32 vdd_absolute_max_voltage_uv;
44 };
45
46 static struct ti_opp_supply_data opp_data;
47
48 /**
49 * struct ti_opp_supply_of_data - device tree match data
50 * @flags: specific type of opp supply
51 * @efuse_voltage_mask: mask required for efuse register representing voltage
52 * @efuse_voltage_uv: Are the efuse entries in micro-volts? if not, assume
53 * milli-volts.
54 */
55 struct ti_opp_supply_of_data {
56 #define OPPDM_EFUSE_CLASS0_OPTIMIZED_VOLTAGE BIT(1)
57 #define OPPDM_HAS_NO_ABB BIT(2)
58 const u8 flags;
59 const u32 efuse_voltage_mask;
60 const bool efuse_voltage_uv;
61 };
62
63 /**
64 * _store_optimized_voltages() - store optimized voltages
65 * @dev: ti opp supply device for which we need to store info
66 * @data: data specific to the device
67 *
68 * Picks up efuse based optimized voltages for VDD unique per device and
69 * stores it in internal data structure for use during transition requests.
70 *
71 * Return: If successful, 0, else appropriate error value.
72 */
_store_optimized_voltages(struct device * dev,struct ti_opp_supply_data * data)73 static int _store_optimized_voltages(struct device *dev,
74 struct ti_opp_supply_data *data)
75 {
76 void __iomem *base;
77 struct property *prop;
78 struct resource *res;
79 const __be32 *val;
80 int proplen, i;
81 int ret = 0;
82 struct ti_opp_supply_optimum_voltage_table *table;
83 const struct ti_opp_supply_of_data *of_data = dev_get_drvdata(dev);
84
85 /* pick up Efuse based voltages */
86 res = platform_get_resource(to_platform_device(dev), IORESOURCE_MEM, 0);
87 if (!res) {
88 dev_err(dev, "Unable to get IO resource\n");
89 ret = -ENODEV;
90 goto out_map;
91 }
92
93 base = ioremap(res->start, resource_size(res));
94 if (!base) {
95 dev_err(dev, "Unable to map Efuse registers\n");
96 ret = -ENOMEM;
97 goto out_map;
98 }
99
100 /* Fetch efuse-settings. */
101 prop = of_find_property(dev->of_node, "ti,efuse-settings", NULL);
102 if (!prop) {
103 dev_err(dev, "No 'ti,efuse-settings' property found\n");
104 ret = -EINVAL;
105 goto out;
106 }
107
108 proplen = prop->length / sizeof(int);
109 data->num_vdd_table = proplen / 2;
110 /* Verify for corrupted OPP entries in dt */
111 if (data->num_vdd_table * 2 * sizeof(int) != prop->length) {
112 dev_err(dev, "Invalid 'ti,efuse-settings'\n");
113 ret = -EINVAL;
114 goto out;
115 }
116
117 ret = of_property_read_u32(dev->of_node, "ti,absolute-max-voltage-uv",
118 &data->vdd_absolute_max_voltage_uv);
119 if (ret) {
120 dev_err(dev, "ti,absolute-max-voltage-uv is missing\n");
121 ret = -EINVAL;
122 goto out;
123 }
124
125 table = kcalloc(data->num_vdd_table, sizeof(*data->vdd_table),
126 GFP_KERNEL);
127 if (!table) {
128 ret = -ENOMEM;
129 goto out;
130 }
131 data->vdd_table = table;
132
133 val = prop->value;
134 for (i = 0; i < data->num_vdd_table; i++, table++) {
135 u32 efuse_offset;
136 u32 tmp;
137
138 table->reference_uv = be32_to_cpup(val++);
139 efuse_offset = be32_to_cpup(val++);
140
141 tmp = readl(base + efuse_offset);
142 tmp &= of_data->efuse_voltage_mask;
143 tmp >>= __ffs(of_data->efuse_voltage_mask);
144
145 table->optimized_uv = of_data->efuse_voltage_uv ? tmp :
146 tmp * 1000;
147
148 dev_dbg(dev, "[%d] efuse=0x%08x volt_table=%d vset=%d\n",
149 i, efuse_offset, table->reference_uv,
150 table->optimized_uv);
151
152 /*
153 * Some older samples might not have optimized efuse
154 * Use reference voltage for those - just add debug message
155 * for them.
156 */
157 if (!table->optimized_uv) {
158 dev_dbg(dev, "[%d] efuse=0x%08x volt_table=%d:vset0\n",
159 i, efuse_offset, table->reference_uv);
160 table->optimized_uv = table->reference_uv;
161 }
162 }
163 out:
164 iounmap(base);
165 out_map:
166 return ret;
167 }
168
169 /**
170 * _free_optimized_voltages() - free resources for optvoltages
171 * @dev: device for which we need to free info
172 * @data: data specific to the device
173 */
_free_optimized_voltages(struct device * dev,struct ti_opp_supply_data * data)174 static void _free_optimized_voltages(struct device *dev,
175 struct ti_opp_supply_data *data)
176 {
177 kfree(data->vdd_table);
178 data->vdd_table = NULL;
179 data->num_vdd_table = 0;
180 }
181
182 /**
183 * _get_optimal_vdd_voltage() - Finds optimal voltage for the supply
184 * @dev: device for which we need to find info
185 * @data: data specific to the device
186 * @reference_uv: reference voltage (OPP voltage) for which we need value
187 *
188 * Return: if a match is found, return optimized voltage, else return
189 * reference_uv, also return reference_uv if no optimization is needed.
190 */
_get_optimal_vdd_voltage(struct device * dev,struct ti_opp_supply_data * data,int reference_uv)191 static int _get_optimal_vdd_voltage(struct device *dev,
192 struct ti_opp_supply_data *data,
193 int reference_uv)
194 {
195 int i;
196 struct ti_opp_supply_optimum_voltage_table *table;
197
198 if (!data->num_vdd_table)
199 return reference_uv;
200
201 table = data->vdd_table;
202 if (!table)
203 return -EINVAL;
204
205 /* Find a exact match - this list is usually very small */
206 for (i = 0; i < data->num_vdd_table; i++, table++)
207 if (table->reference_uv == reference_uv)
208 return table->optimized_uv;
209
210 /* IF things are screwed up, we'd make a mess on console.. ratelimit */
211 dev_err_ratelimited(dev, "%s: Failed optimized voltage match for %d\n",
212 __func__, reference_uv);
213 return reference_uv;
214 }
215
_opp_set_voltage(struct device * dev,struct dev_pm_opp_supply * supply,int new_target_uv,struct regulator * reg,char * reg_name)216 static int _opp_set_voltage(struct device *dev,
217 struct dev_pm_opp_supply *supply,
218 int new_target_uv, struct regulator *reg,
219 char *reg_name)
220 {
221 int ret;
222 unsigned long vdd_uv, uv_max;
223
224 if (new_target_uv)
225 vdd_uv = new_target_uv;
226 else
227 vdd_uv = supply->u_volt;
228
229 /*
230 * If we do have an absolute max voltage specified, then we should
231 * use that voltage instead to allow for cases where the voltage rails
232 * are ganged (example if we set the max for an opp as 1.12v, and
233 * the absolute max is 1.5v, for another rail to get 1.25v, it cannot
234 * be achieved if the regulator is constrainted to max of 1.12v, even
235 * if it can function at 1.25v
236 */
237 if (opp_data.vdd_absolute_max_voltage_uv)
238 uv_max = opp_data.vdd_absolute_max_voltage_uv;
239 else
240 uv_max = supply->u_volt_max;
241
242 if (vdd_uv > uv_max ||
243 vdd_uv < supply->u_volt_min ||
244 supply->u_volt_min > uv_max) {
245 dev_warn(dev,
246 "Invalid range voltages [Min:%lu target:%lu Max:%lu]\n",
247 supply->u_volt_min, vdd_uv, uv_max);
248 return -EINVAL;
249 }
250
251 dev_dbg(dev, "%s scaling to %luuV[min %luuV max %luuV]\n", reg_name,
252 vdd_uv, supply->u_volt_min,
253 uv_max);
254
255 ret = regulator_set_voltage_triplet(reg,
256 supply->u_volt_min,
257 vdd_uv,
258 uv_max);
259 if (ret) {
260 dev_err(dev, "%s failed for %luuV[min %luuV max %luuV]\n",
261 reg_name, vdd_uv, supply->u_volt_min,
262 uv_max);
263 return ret;
264 }
265
266 return 0;
267 }
268
269 /**
270 * ti_opp_supply_set_opp() - do the opp supply transition
271 * @data: information on regulators and new and old opps provided by
272 * opp core to use in transition
273 *
274 * Return: If successful, 0, else appropriate error value.
275 */
ti_opp_supply_set_opp(struct dev_pm_set_opp_data * data)276 static int ti_opp_supply_set_opp(struct dev_pm_set_opp_data *data)
277 {
278 struct dev_pm_opp_supply *old_supply_vdd = &data->old_opp.supplies[0];
279 struct dev_pm_opp_supply *old_supply_vbb = &data->old_opp.supplies[1];
280 struct dev_pm_opp_supply *new_supply_vdd = &data->new_opp.supplies[0];
281 struct dev_pm_opp_supply *new_supply_vbb = &data->new_opp.supplies[1];
282 struct device *dev = data->dev;
283 unsigned long old_freq = data->old_opp.rate, freq = data->new_opp.rate;
284 struct clk *clk = data->clk;
285 struct regulator *vdd_reg = data->regulators[0];
286 struct regulator *vbb_reg = data->regulators[1];
287 int vdd_uv;
288 int ret;
289
290 vdd_uv = _get_optimal_vdd_voltage(dev, &opp_data,
291 new_supply_vdd->u_volt);
292
293 if (new_supply_vdd->u_volt_min < vdd_uv)
294 new_supply_vdd->u_volt_min = vdd_uv;
295
296 /* Scaling up? Scale voltage before frequency */
297 if (freq > old_freq) {
298 ret = _opp_set_voltage(dev, new_supply_vdd, vdd_uv, vdd_reg,
299 "vdd");
300 if (ret)
301 goto restore_voltage;
302
303 ret = _opp_set_voltage(dev, new_supply_vbb, 0, vbb_reg, "vbb");
304 if (ret)
305 goto restore_voltage;
306 }
307
308 /* Change frequency */
309 dev_dbg(dev, "%s: switching OPP: %lu Hz --> %lu Hz\n",
310 __func__, old_freq, freq);
311
312 ret = clk_set_rate(clk, freq);
313 if (ret) {
314 dev_err(dev, "%s: failed to set clock rate: %d\n", __func__,
315 ret);
316 goto restore_voltage;
317 }
318
319 /* Scaling down? Scale voltage after frequency */
320 if (freq < old_freq) {
321 ret = _opp_set_voltage(dev, new_supply_vbb, 0, vbb_reg, "vbb");
322 if (ret)
323 goto restore_freq;
324
325 ret = _opp_set_voltage(dev, new_supply_vdd, vdd_uv, vdd_reg,
326 "vdd");
327 if (ret)
328 goto restore_freq;
329 }
330
331 return 0;
332
333 restore_freq:
334 ret = clk_set_rate(clk, old_freq);
335 if (ret)
336 dev_err(dev, "%s: failed to restore old-freq (%lu Hz)\n",
337 __func__, old_freq);
338 restore_voltage:
339 /* This shouldn't harm even if the voltages weren't updated earlier */
340 if (old_supply_vdd->u_volt) {
341 ret = _opp_set_voltage(dev, old_supply_vbb, 0, vbb_reg, "vbb");
342 if (ret)
343 return ret;
344
345 ret = _opp_set_voltage(dev, old_supply_vdd, 0, vdd_reg,
346 "vdd");
347 if (ret)
348 return ret;
349 }
350
351 return ret;
352 }
353
354 static const struct ti_opp_supply_of_data omap_generic_of_data = {
355 };
356
357 static const struct ti_opp_supply_of_data omap_omap5_of_data = {
358 .flags = OPPDM_EFUSE_CLASS0_OPTIMIZED_VOLTAGE,
359 .efuse_voltage_mask = 0xFFF,
360 .efuse_voltage_uv = false,
361 };
362
363 static const struct ti_opp_supply_of_data omap_omap5core_of_data = {
364 .flags = OPPDM_EFUSE_CLASS0_OPTIMIZED_VOLTAGE | OPPDM_HAS_NO_ABB,
365 .efuse_voltage_mask = 0xFFF,
366 .efuse_voltage_uv = false,
367 };
368
369 static const struct of_device_id ti_opp_supply_of_match[] = {
370 {.compatible = "ti,omap-opp-supply", .data = &omap_generic_of_data},
371 {.compatible = "ti,omap5-opp-supply", .data = &omap_omap5_of_data},
372 {.compatible = "ti,omap5-core-opp-supply",
373 .data = &omap_omap5core_of_data},
374 {},
375 };
376 MODULE_DEVICE_TABLE(of, ti_opp_supply_of_match);
377
ti_opp_supply_probe(struct platform_device * pdev)378 static int ti_opp_supply_probe(struct platform_device *pdev)
379 {
380 struct device *dev = &pdev->dev;
381 struct device *cpu_dev = get_cpu_device(0);
382 const struct of_device_id *match;
383 const struct ti_opp_supply_of_data *of_data;
384 int ret = 0;
385
386 match = of_match_device(ti_opp_supply_of_match, dev);
387 if (!match) {
388 /* We do not expect this to happen */
389 dev_err(dev, "%s: Unable to match device\n", __func__);
390 return -ENODEV;
391 }
392 if (!match->data) {
393 /* Again, unlikely.. but mistakes do happen */
394 dev_err(dev, "%s: Bad data in match\n", __func__);
395 return -EINVAL;
396 }
397 of_data = match->data;
398
399 dev_set_drvdata(dev, (void *)of_data);
400
401 /* If we need optimized voltage */
402 if (of_data->flags & OPPDM_EFUSE_CLASS0_OPTIMIZED_VOLTAGE) {
403 ret = _store_optimized_voltages(dev, &opp_data);
404 if (ret)
405 return ret;
406 }
407
408 ret = PTR_ERR_OR_ZERO(dev_pm_opp_register_set_opp_helper(cpu_dev,
409 ti_opp_supply_set_opp));
410 if (ret)
411 _free_optimized_voltages(dev, &opp_data);
412
413 return ret;
414 }
415
416 static struct platform_driver ti_opp_supply_driver = {
417 .probe = ti_opp_supply_probe,
418 .driver = {
419 .name = "ti_opp_supply",
420 .of_match_table = of_match_ptr(ti_opp_supply_of_match),
421 },
422 };
423 module_platform_driver(ti_opp_supply_driver);
424
425 MODULE_DESCRIPTION("Texas Instruments OMAP OPP Supply driver");
426 MODULE_AUTHOR("Texas Instruments Inc.");
427 MODULE_LICENSE("GPL v2");
428