1 /*
2  * ROHM BD9571MWV-M regulator driver
3  *
4  * Copyright (C) 2017 Marek Vasut <marek.vasut+renesas@gmail.com>
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  *
10  * This program is distributed "as is" WITHOUT ANY WARRANTY of any
11  * kind, whether expressed or implied; without even the implied warranty
12  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License version 2 for more details.
14  *
15  * Based on the TPS65086 driver
16  *
17  * NOTE: VD09 is missing
18  */
19 
20 #include <linux/module.h>
21 #include <linux/of.h>
22 #include <linux/platform_device.h>
23 #include <linux/regulator/driver.h>
24 
25 #include <linux/mfd/bd9571mwv.h>
26 
27 struct bd9571mwv_reg {
28 	struct bd9571mwv *bd;
29 
30 	/* DDR Backup Power */
31 	u8 bkup_mode_cnt_keepon;	/* from "rohm,ddr-backup-power" */
32 	u8 bkup_mode_cnt_saved;
33 	bool bkup_mode_enabled;
34 
35 	/* Power switch type */
36 	bool rstbmode_level;
37 	bool rstbmode_pulse;
38 };
39 
40 enum bd9571mwv_regulators { VD09, VD18, VD25, VD33, DVFS };
41 
42 #define BD9571MWV_REG(_name, _of, _id, _ops, _vr, _vm, _nv, _min, _step, _lmin)\
43 	{							\
44 		.name			= _name,		\
45 		.of_match		= of_match_ptr(_of),	\
46 		.regulators_node	= "regulators",		\
47 		.id			= _id,			\
48 		.ops			= &_ops,		\
49 		.n_voltages		= _nv,			\
50 		.type			= REGULATOR_VOLTAGE,	\
51 		.owner			= THIS_MODULE,		\
52 		.vsel_reg		= _vr,			\
53 		.vsel_mask		= _vm,			\
54 		.min_uV			= _min,			\
55 		.uV_step		= _step,		\
56 		.linear_min_sel		= _lmin,		\
57 	}
58 
59 static int bd9571mwv_avs_get_moni_state(struct regulator_dev *rdev)
60 {
61 	unsigned int val;
62 	int ret;
63 
64 	ret = regmap_read(rdev->regmap, BD9571MWV_AVS_SET_MONI, &val);
65 	if (ret != 0)
66 		return ret;
67 
68 	return val & BD9571MWV_AVS_SET_MONI_MASK;
69 }
70 
71 static int bd9571mwv_avs_set_voltage_sel_regmap(struct regulator_dev *rdev,
72 						unsigned int sel)
73 {
74 	int ret;
75 
76 	ret = bd9571mwv_avs_get_moni_state(rdev);
77 	if (ret < 0)
78 		return ret;
79 
80 	return regmap_write_bits(rdev->regmap, BD9571MWV_AVS_VD09_VID(ret),
81 				 rdev->desc->vsel_mask, sel);
82 }
83 
84 static int bd9571mwv_avs_get_voltage_sel_regmap(struct regulator_dev *rdev)
85 {
86 	unsigned int val;
87 	int ret;
88 
89 	ret = bd9571mwv_avs_get_moni_state(rdev);
90 	if (ret < 0)
91 		return ret;
92 
93 	ret = regmap_read(rdev->regmap, BD9571MWV_AVS_VD09_VID(ret), &val);
94 	if (ret != 0)
95 		return ret;
96 
97 	val &= rdev->desc->vsel_mask;
98 	val >>= ffs(rdev->desc->vsel_mask) - 1;
99 
100 	return val;
101 }
102 
103 static int bd9571mwv_reg_set_voltage_sel_regmap(struct regulator_dev *rdev,
104 						unsigned int sel)
105 {
106 	return regmap_write_bits(rdev->regmap, BD9571MWV_DVFS_SETVID,
107 				 rdev->desc->vsel_mask, sel);
108 }
109 
110 /* Operations permitted on AVS voltage regulator */
111 static struct regulator_ops avs_ops = {
112 	.set_voltage_sel	= bd9571mwv_avs_set_voltage_sel_regmap,
113 	.map_voltage		= regulator_map_voltage_linear,
114 	.get_voltage_sel	= bd9571mwv_avs_get_voltage_sel_regmap,
115 	.list_voltage		= regulator_list_voltage_linear,
116 };
117 
118 /* Operations permitted on voltage regulators */
119 static struct regulator_ops reg_ops = {
120 	.set_voltage_sel	= bd9571mwv_reg_set_voltage_sel_regmap,
121 	.map_voltage		= regulator_map_voltage_linear,
122 	.get_voltage_sel	= regulator_get_voltage_sel_regmap,
123 	.list_voltage		= regulator_list_voltage_linear,
124 };
125 
126 /* Operations permitted on voltage monitors */
127 static struct regulator_ops vid_ops = {
128 	.map_voltage		= regulator_map_voltage_linear,
129 	.get_voltage_sel	= regulator_get_voltage_sel_regmap,
130 	.list_voltage		= regulator_list_voltage_linear,
131 };
132 
133 static struct regulator_desc regulators[] = {
134 	BD9571MWV_REG("VD09", "vd09", VD09, avs_ops, 0, 0x7f,
135 		      0x80, 600000, 10000, 0x3c),
136 	BD9571MWV_REG("VD18", "vd18", VD18, vid_ops, BD9571MWV_VD18_VID, 0xf,
137 		      16, 1625000, 25000, 0),
138 	BD9571MWV_REG("VD25", "vd25", VD25, vid_ops, BD9571MWV_VD25_VID, 0xf,
139 		      16, 2150000, 50000, 0),
140 	BD9571MWV_REG("VD33", "vd33", VD33, vid_ops, BD9571MWV_VD33_VID, 0xf,
141 		      11, 2800000, 100000, 0),
142 	BD9571MWV_REG("DVFS", "dvfs", DVFS, reg_ops,
143 		      BD9571MWV_DVFS_MONIVDAC, 0x7f,
144 		      0x80, 600000, 10000, 0x3c),
145 };
146 
147 #ifdef CONFIG_PM_SLEEP
148 static int bd9571mwv_bkup_mode_read(struct bd9571mwv *bd, unsigned int *mode)
149 {
150 	int ret;
151 
152 	ret = regmap_read(bd->regmap, BD9571MWV_BKUP_MODE_CNT, mode);
153 	if (ret) {
154 		dev_err(bd->dev, "failed to read backup mode (%d)\n", ret);
155 		return ret;
156 	}
157 
158 	return 0;
159 }
160 
161 static int bd9571mwv_bkup_mode_write(struct bd9571mwv *bd, unsigned int mode)
162 {
163 	int ret;
164 
165 	ret = regmap_write(bd->regmap, BD9571MWV_BKUP_MODE_CNT, mode);
166 	if (ret) {
167 		dev_err(bd->dev, "failed to configure backup mode 0x%x (%d)\n",
168 			mode, ret);
169 		return ret;
170 	}
171 
172 	return 0;
173 }
174 
175 static ssize_t backup_mode_show(struct device *dev,
176 				struct device_attribute *attr, char *buf)
177 {
178 	struct bd9571mwv_reg *bdreg = dev_get_drvdata(dev);
179 
180 	return sprintf(buf, "%s\n", bdreg->bkup_mode_enabled ? "on" : "off");
181 }
182 
183 static ssize_t backup_mode_store(struct device *dev,
184 				 struct device_attribute *attr,
185 				 const char *buf, size_t count)
186 {
187 	struct bd9571mwv_reg *bdreg = dev_get_drvdata(dev);
188 	unsigned int mode;
189 	int ret;
190 
191 	if (!count)
192 		return 0;
193 
194 	ret = kstrtobool(buf, &bdreg->bkup_mode_enabled);
195 	if (ret)
196 		return ret;
197 
198 	if (!bdreg->rstbmode_level)
199 		return count;
200 
201 	/*
202 	 * Configure DDR Backup Mode, to change the role of the accessory power
203 	 * switch from a power switch to a wake-up switch, or vice versa
204 	 */
205 	ret = bd9571mwv_bkup_mode_read(bdreg->bd, &mode);
206 	if (ret)
207 		return ret;
208 
209 	mode &= ~BD9571MWV_BKUP_MODE_CNT_KEEPON_MASK;
210 	if (bdreg->bkup_mode_enabled)
211 		mode |= bdreg->bkup_mode_cnt_keepon;
212 
213 	ret = bd9571mwv_bkup_mode_write(bdreg->bd, mode);
214 	if (ret)
215 		return ret;
216 
217 	return count;
218 }
219 
220 static DEVICE_ATTR_RW(backup_mode);
221 
222 static int bd9571mwv_suspend(struct device *dev)
223 {
224 	struct bd9571mwv_reg *bdreg = dev_get_drvdata(dev);
225 	unsigned int mode;
226 	int ret;
227 
228 	if (!bdreg->bkup_mode_enabled)
229 		return 0;
230 
231 	/* Save DDR Backup Mode */
232 	ret = bd9571mwv_bkup_mode_read(bdreg->bd, &mode);
233 	if (ret)
234 		return ret;
235 
236 	bdreg->bkup_mode_cnt_saved = mode;
237 
238 	if (!bdreg->rstbmode_pulse)
239 		return 0;
240 
241 	/* Enable DDR Backup Mode */
242 	mode &= ~BD9571MWV_BKUP_MODE_CNT_KEEPON_MASK;
243 	mode |= bdreg->bkup_mode_cnt_keepon;
244 
245 	if (mode != bdreg->bkup_mode_cnt_saved)
246 		return bd9571mwv_bkup_mode_write(bdreg->bd, mode);
247 
248 	return 0;
249 }
250 
251 static int bd9571mwv_resume(struct device *dev)
252 {
253 	struct bd9571mwv_reg *bdreg = dev_get_drvdata(dev);
254 
255 	if (!bdreg->bkup_mode_enabled)
256 		return 0;
257 
258 	/* Restore DDR Backup Mode */
259 	return bd9571mwv_bkup_mode_write(bdreg->bd, bdreg->bkup_mode_cnt_saved);
260 }
261 
262 static const struct dev_pm_ops bd9571mwv_pm  = {
263 	SET_SYSTEM_SLEEP_PM_OPS(bd9571mwv_suspend, bd9571mwv_resume)
264 };
265 
266 static int bd9571mwv_regulator_remove(struct platform_device *pdev)
267 {
268 	device_remove_file(&pdev->dev, &dev_attr_backup_mode);
269 	return 0;
270 }
271 #define DEV_PM_OPS	&bd9571mwv_pm
272 #else
273 #define DEV_PM_OPS	NULL
274 #define bd9571mwv_regulator_remove	NULL
275 #endif /* CONFIG_PM_SLEEP */
276 
277 static int bd9571mwv_regulator_probe(struct platform_device *pdev)
278 {
279 	struct bd9571mwv *bd = dev_get_drvdata(pdev->dev.parent);
280 	struct regulator_config config = { };
281 	struct bd9571mwv_reg *bdreg;
282 	struct regulator_dev *rdev;
283 	unsigned int val;
284 	int i;
285 
286 	bdreg = devm_kzalloc(&pdev->dev, sizeof(*bdreg), GFP_KERNEL);
287 	if (!bdreg)
288 		return -ENOMEM;
289 
290 	bdreg->bd = bd;
291 
292 	platform_set_drvdata(pdev, bdreg);
293 
294 	config.dev = &pdev->dev;
295 	config.dev->of_node = bd->dev->of_node;
296 	config.driver_data = bd;
297 	config.regmap = bd->regmap;
298 
299 	for (i = 0; i < ARRAY_SIZE(regulators); i++) {
300 		rdev = devm_regulator_register(&pdev->dev, &regulators[i],
301 					       &config);
302 		if (IS_ERR(rdev)) {
303 			dev_err(bd->dev, "failed to register %s regulator\n",
304 				pdev->name);
305 			return PTR_ERR(rdev);
306 		}
307 	}
308 
309 	val = 0;
310 	of_property_read_u32(bd->dev->of_node, "rohm,ddr-backup-power", &val);
311 	if (val & ~BD9571MWV_BKUP_MODE_CNT_KEEPON_MASK) {
312 		dev_err(bd->dev, "invalid %s mode %u\n",
313 			"rohm,ddr-backup-power", val);
314 		return -EINVAL;
315 	}
316 	bdreg->bkup_mode_cnt_keepon = val;
317 
318 	bdreg->rstbmode_level = of_property_read_bool(bd->dev->of_node,
319 						      "rohm,rstbmode-level");
320 	bdreg->rstbmode_pulse = of_property_read_bool(bd->dev->of_node,
321 						      "rohm,rstbmode-pulse");
322 	if (bdreg->rstbmode_level && bdreg->rstbmode_pulse) {
323 		dev_err(bd->dev, "only one rohm,rstbmode-* may be specified");
324 		return -EINVAL;
325 	}
326 
327 #ifdef CONFIG_PM_SLEEP
328 	if (bdreg->bkup_mode_cnt_keepon) {
329 		int ret;
330 
331 		/*
332 		 * Backup mode is enabled by default in pulse mode, but needs
333 		 * explicit user setup in level mode.
334 		 */
335 		bdreg->bkup_mode_enabled = bdreg->rstbmode_pulse;
336 
337 		ret = device_create_file(&pdev->dev, &dev_attr_backup_mode);
338 		if (ret)
339 			return ret;
340 	}
341 #endif /* CONFIG_PM_SLEEP */
342 
343 	return 0;
344 }
345 
346 static const struct platform_device_id bd9571mwv_regulator_id_table[] = {
347 	{ "bd9571mwv-regulator", },
348 	{ /* sentinel */ }
349 };
350 MODULE_DEVICE_TABLE(platform, bd9571mwv_regulator_id_table);
351 
352 static struct platform_driver bd9571mwv_regulator_driver = {
353 	.driver = {
354 		.name = "bd9571mwv-regulator",
355 		.pm = DEV_PM_OPS,
356 	},
357 	.probe = bd9571mwv_regulator_probe,
358 	.remove = bd9571mwv_regulator_remove,
359 	.id_table = bd9571mwv_regulator_id_table,
360 };
361 module_platform_driver(bd9571mwv_regulator_driver);
362 
363 MODULE_AUTHOR("Marek Vasut <marek.vasut+renesas@gmail.com>");
364 MODULE_DESCRIPTION("BD9571MWV Regulator driver");
365 MODULE_LICENSE("GPL v2");
366