1// SPDX-License-Identifier: GPL-2.0+
2//
3// Copyright (C) 2011 Freescale Semiconductor, Inc. All Rights Reserved.
4
5#include <linux/slab.h>
6#include <linux/device.h>
7#include <linux/module.h>
8#include <linux/mfd/syscon.h>
9#include <linux/err.h>
10#include <linux/io.h>
11#include <linux/platform_device.h>
12#include <linux/of.h>
13#include <linux/of_address.h>
14#include <linux/regmap.h>
15#include <linux/regulator/driver.h>
16#include <linux/regulator/of_regulator.h>
17#include <linux/regulator/machine.h>
18
19#define LDO_RAMP_UP_UNIT_IN_CYCLES 64 /* 64 cycles per step */
20#define LDO_RAMP_UP_FREQ_IN_MHZ 24 /* cycle based on 24M OSC */
21
22#define LDO_POWER_GATE 0x00
23#define LDO_FET_FULL_ON 0x1f
24
25struct anatop_regulator {
26 u32 control_reg;
27 struct regmap *anatop;
28 int vol_bit_shift;
29 int vol_bit_width;
30 u32 delay_reg;
31 int delay_bit_shift;
32 int delay_bit_width;
33 int min_bit_val;
34 int min_voltage;
35 int max_voltage;
36 struct regulator_desc rdesc;
37 struct regulator_init_data *initdata;
38 bool bypass;
39 int sel;
40};
41
42static int anatop_regmap_set_voltage_time_sel(struct regulator_dev *reg,
43 unsigned int old_sel,
44 unsigned int new_sel)
45{
46 struct anatop_regulator *anatop_reg = rdev_get_drvdata(reg);
47 u32 val;
48 int ret = 0;
49
50 /* check whether need to care about LDO ramp up speed */
51 if (anatop_reg->delay_bit_width && new_sel > old_sel) {
52 /*
53 * the delay for LDO ramp up time is
54 * based on the register setting, we need
55 * to calculate how many steps LDO need to
56 * ramp up, and how much delay needed. (us)
57 */
58 regmap_read(anatop_reg->anatop, anatop_reg->delay_reg, &val);
59 val = (val >> anatop_reg->delay_bit_shift) &
60 ((1 << anatop_reg->delay_bit_width) - 1);
61 ret = (new_sel - old_sel) * (LDO_RAMP_UP_UNIT_IN_CYCLES <<
62 val) / LDO_RAMP_UP_FREQ_IN_MHZ + 1;
63 }
64
65 return ret;
66}
67
68static int anatop_regmap_enable(struct regulator_dev *reg)
69{
70 struct anatop_regulator *anatop_reg = rdev_get_drvdata(reg);
71 int sel;
72
73 sel = anatop_reg->bypass ? LDO_FET_FULL_ON : anatop_reg->sel;
74 return regulator_set_voltage_sel_regmap(reg, sel);
75}
76
77static int anatop_regmap_disable(struct regulator_dev *reg)
78{
79 return regulator_set_voltage_sel_regmap(reg, LDO_POWER_GATE);
80}
81
82static int anatop_regmap_is_enabled(struct regulator_dev *reg)
83{
84 return regulator_get_voltage_sel_regmap(reg) != LDO_POWER_GATE;
85}
86
87static int anatop_regmap_core_set_voltage_sel(struct regulator_dev *reg,
88 unsigned selector)
89{
90 struct anatop_regulator *anatop_reg = rdev_get_drvdata(reg);
91 int ret;
92
93 if (anatop_reg->bypass || !anatop_regmap_is_enabled(reg)) {
94 anatop_reg->sel = selector;
95 return 0;
96 }
97
98 ret = regulator_set_voltage_sel_regmap(reg, selector);
99 if (!ret)
100 anatop_reg->sel = selector;
101 return ret;
102}
103
104static int anatop_regmap_core_get_voltage_sel(struct regulator_dev *reg)
105{
106 struct anatop_regulator *anatop_reg = rdev_get_drvdata(reg);
107
108 if (anatop_reg->bypass || !anatop_regmap_is_enabled(reg))
109 return anatop_reg->sel;
110
111 return regulator_get_voltage_sel_regmap(reg);
112}
113
114static int anatop_regmap_get_bypass(struct regulator_dev *reg, bool *enable)
115{
116 struct anatop_regulator *anatop_reg = rdev_get_drvdata(reg);
117 int sel;
118
119 sel = regulator_get_voltage_sel_regmap(reg);
120 if (sel == LDO_FET_FULL_ON)
121 WARN_ON(!anatop_reg->bypass);
122 else if (sel != LDO_POWER_GATE)
123 WARN_ON(anatop_reg->bypass);
124
125 *enable = anatop_reg->bypass;
126 return 0;
127}
128
129static int anatop_regmap_set_bypass(struct regulator_dev *reg, bool enable)
130{
131 struct anatop_regulator *anatop_reg = rdev_get_drvdata(reg);
132 int sel;
133
134 if (enable == anatop_reg->bypass)
135 return 0;
136
137 sel = enable ? LDO_FET_FULL_ON : anatop_reg->sel;
138 anatop_reg->bypass = enable;
139
140 return regulator_set_voltage_sel_regmap(reg, sel);
141}
142
143static struct regulator_ops anatop_rops = {
144 .set_voltage_sel = regulator_set_voltage_sel_regmap,
145 .get_voltage_sel = regulator_get_voltage_sel_regmap,
146 .list_voltage = regulator_list_voltage_linear,
147 .map_voltage = regulator_map_voltage_linear,
148};
149
150static struct regulator_ops anatop_core_rops = {
151 .enable = anatop_regmap_enable,
152 .disable = anatop_regmap_disable,
153 .is_enabled = anatop_regmap_is_enabled,
154 .set_voltage_sel = anatop_regmap_core_set_voltage_sel,
155 .set_voltage_time_sel = anatop_regmap_set_voltage_time_sel,
156 .get_voltage_sel = anatop_regmap_core_get_voltage_sel,
157 .list_voltage = regulator_list_voltage_linear,
158 .map_voltage = regulator_map_voltage_linear,
159 .get_bypass = anatop_regmap_get_bypass,
160 .set_bypass = anatop_regmap_set_bypass,
161};
162
163static int anatop_regulator_probe(struct platform_device *pdev)
164{
165 struct device *dev = &pdev->dev;
166 struct device_node *np = dev->of_node;
167 struct device_node *anatop_np;
168 struct regulator_desc *rdesc;
169 struct regulator_dev *rdev;
170 struct anatop_regulator *sreg;
171 struct regulator_init_data *initdata;
172 struct regulator_config config = { };
173 int ret = 0;
174 u32 val;
175
176 sreg = devm_kzalloc(dev, sizeof(*sreg), GFP_KERNEL);
177 if (!sreg)
178 return -ENOMEM;
179
180 rdesc = &sreg->rdesc;
181 rdesc->type = REGULATOR_VOLTAGE;
182 rdesc->owner = THIS_MODULE;
183
184 of_property_read_string(np, "regulator-name", &rdesc->name);
185 if (!rdesc->name) {
186 dev_err(dev, "failed to get a regulator-name\n");
187 return -EINVAL;
188 }
189
190 initdata = of_get_regulator_init_data(dev, np, rdesc);
191 if (!initdata)
192 return -ENOMEM;
193
194 initdata->supply_regulator = "vin";
195 sreg->initdata = initdata;
196
197 anatop_np = of_get_parent(np);
198 if (!anatop_np)
199 return -ENODEV;
200 sreg->anatop = syscon_node_to_regmap(anatop_np);
201 of_node_put(anatop_np);
202 if (IS_ERR(sreg->anatop))
203 return PTR_ERR(sreg->anatop);
204
205 ret = of_property_read_u32(np, "anatop-reg-offset",
206 &sreg->control_reg);
207 if (ret) {
208 dev_err(dev, "no anatop-reg-offset property set\n");
209 return ret;
210 }
211 ret = of_property_read_u32(np, "anatop-vol-bit-width",
212 &sreg->vol_bit_width);
213 if (ret) {
214 dev_err(dev, "no anatop-vol-bit-width property set\n");
215 return ret;
216 }
217 ret = of_property_read_u32(np, "anatop-vol-bit-shift",
218 &sreg->vol_bit_shift);
219 if (ret) {
220 dev_err(dev, "no anatop-vol-bit-shift property set\n");
221 return ret;
222 }
223 ret = of_property_read_u32(np, "anatop-min-bit-val",
224 &sreg->min_bit_val);
225 if (ret) {
226 dev_err(dev, "no anatop-min-bit-val property set\n");
227 return ret;
228 }
229 ret = of_property_read_u32(np, "anatop-min-voltage",
230 &sreg->min_voltage);
231 if (ret) {
232 dev_err(dev, "no anatop-min-voltage property set\n");
233 return ret;
234 }
235 ret = of_property_read_u32(np, "anatop-max-voltage",
236 &sreg->max_voltage);
237 if (ret) {
238 dev_err(dev, "no anatop-max-voltage property set\n");
239 return ret;
240 }
241
242 /* read LDO ramp up setting, only for core reg */
243 of_property_read_u32(np, "anatop-delay-reg-offset",
244 &sreg->delay_reg);
245 of_property_read_u32(np, "anatop-delay-bit-width",
246 &sreg->delay_bit_width);
247 of_property_read_u32(np, "anatop-delay-bit-shift",
248 &sreg->delay_bit_shift);
249
250 rdesc->n_voltages = (sreg->max_voltage - sreg->min_voltage) / 25000 + 1
251 + sreg->min_bit_val;
252 rdesc->min_uV = sreg->min_voltage;
253 rdesc->uV_step = 25000;
254 rdesc->linear_min_sel = sreg->min_bit_val;
255 rdesc->vsel_reg = sreg->control_reg;
256 rdesc->vsel_mask = ((1 << sreg->vol_bit_width) - 1) <<
257 sreg->vol_bit_shift;
258 rdesc->min_dropout_uV = 125000;
259
260 config.dev = &pdev->dev;
261 config.init_data = initdata;
262 config.driver_data = sreg;
263 config.of_node = pdev->dev.of_node;
264 config.regmap = sreg->anatop;
265
266 /* Only core regulators have the ramp up delay configuration. */
267 if (sreg->control_reg && sreg->delay_bit_width) {
268 rdesc->ops = &anatop_core_rops;
269
270 ret = regmap_read(config.regmap, rdesc->vsel_reg, &val);
271 if (ret) {
272 dev_err(dev, "failed to read initial state\n");
273 return ret;
274 }
275
276 sreg->sel = (val & rdesc->vsel_mask) >> sreg->vol_bit_shift;
277 if (sreg->sel == LDO_FET_FULL_ON) {
278 sreg->sel = 0;
279 sreg->bypass = true;
280 }
281
282 /*
283 * In case vddpu was disabled by the bootloader, we need to set
284 * a sane default until imx6-cpufreq was probed and changes the
285 * voltage to the correct value. In this case we set 1.25V.
286 */
287 if (!sreg->sel && !strcmp(rdesc->name, "vddpu"))
288 sreg->sel = 22;
289
290 /* set the default voltage of the pcie phy to be 1.100v */
291 if (!sreg->sel && !strcmp(rdesc->name, "vddpcie"))
292 sreg->sel = 0x10;
293
294 if (!sreg->bypass && !sreg->sel) {
295 dev_err(&pdev->dev, "Failed to read a valid default voltage selector.\n");
296 return -EINVAL;
297 }
298 } else {
299 u32 enable_bit;
300
301 rdesc->ops = &anatop_rops;
302
303 if (!of_property_read_u32(np, "anatop-enable-bit",
304 &enable_bit)) {
305 anatop_rops.enable = regulator_enable_regmap;
306 anatop_rops.disable = regulator_disable_regmap;
307 anatop_rops.is_enabled = regulator_is_enabled_regmap;
308
309 rdesc->enable_reg = sreg->control_reg;
310 rdesc->enable_mask = BIT(enable_bit);
311 }
312 }
313
314 /* register regulator */
315 rdev = devm_regulator_register(dev, rdesc, &config);
316 if (IS_ERR(rdev)) {
317 dev_err(dev, "failed to register %s\n",
318 rdesc->name);
319 return PTR_ERR(rdev);
320 }
321
322 platform_set_drvdata(pdev, rdev);
323
324 return 0;
325}
326
327static const struct of_device_id of_anatop_regulator_match_tbl[] = {
328 { .compatible = "fsl,anatop-regulator", },
329 { /* end */ }
330};
331MODULE_DEVICE_TABLE(of, of_anatop_regulator_match_tbl);
332
333static struct platform_driver anatop_regulator_driver = {
334 .driver = {
335 .name = "anatop_regulator",
336 .of_match_table = of_anatop_regulator_match_tbl,
337 },
338 .probe = anatop_regulator_probe,
339};
340
341static int __init anatop_regulator_init(void)
342{
343 return platform_driver_register(&anatop_regulator_driver);
344}
345postcore_initcall(anatop_regulator_init);
346
347static void __exit anatop_regulator_exit(void)
348{
349 platform_driver_unregister(&anatop_regulator_driver);
350}
351module_exit(anatop_regulator_exit);
352
353MODULE_AUTHOR("Nancy Chen <Nancy.Chen@freescale.com>");
354MODULE_AUTHOR("Ying-Chun Liu (PaulLiu) <paul.liu@linaro.org>");
355MODULE_DESCRIPTION("ANATOP Regulator driver");
356MODULE_LICENSE("GPL v2");
357MODULE_ALIAS("platform:anatop_regulator");
358