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 
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 
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 
69 static int anatop_regmap_disable(struct regulator_dev *reg)
70 {
71 	return regulator_set_voltage_sel_regmap(reg, LDO_POWER_GATE);
72 }
73 
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 
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 
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 
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 
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 
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 
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 
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