GNU Linux-libre 6.9.1-gnu
[releases.git] / drivers / opp / ti-opp-supply.c
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  */
30 struct 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  */
43 struct 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
51 static 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  */
60 struct 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  */
78 static 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         }
168 out:
169         iounmap(base);
170 out_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  */
179 static 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  */
196 static 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
221 static 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 */
275 static 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
329 restore_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
349 static const struct ti_opp_supply_of_data omap_generic_of_data = {
350 };
351
352 static 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
358 static 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
364 static 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 };
371 MODULE_DEVICE_TABLE(of, ti_opp_supply_of_match);
372
373 static 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
402 static 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 };
409 module_platform_driver(ti_opp_supply_driver);
410
411 MODULE_DESCRIPTION("Texas Instruments OMAP OPP Supply driver");
412 MODULE_AUTHOR("Texas Instruments Inc.");
413 MODULE_LICENSE("GPL v2");