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