1 // SPDX-License-Identifier: GPL-2.0+
2 //
3 // max8997_charger.c - Power supply consumer driver for the Maxim 8997/8966
4 //
5 //  Copyright (C) 2011 Samsung Electronics
6 //  MyungJoo Ham <myungjoo.ham@samsung.com>
7 
8 #include <linux/err.h>
9 #include <linux/extcon.h>
10 #include <linux/module.h>
11 #include <linux/slab.h>
12 #include <linux/platform_device.h>
13 #include <linux/power_supply.h>
14 #include <linux/mfd/max8997.h>
15 #include <linux/mfd/max8997-private.h>
16 #include <linux/regulator/consumer.h>
17 #include <linux/devm-helpers.h>
18 
19 /* MAX8997_REG_STATUS4 */
20 #define DCINOK_SHIFT		1
21 #define DCINOK_MASK		(1 << DCINOK_SHIFT)
22 #define DETBAT_SHIFT		2
23 #define DETBAT_MASK		(1 << DETBAT_SHIFT)
24 
25 /* MAX8997_REG_MBCCTRL1 */
26 #define TFCH_SHIFT		4
27 #define TFCH_MASK		(7 << TFCH_SHIFT)
28 
29 /* MAX8997_REG_MBCCTRL5 */
30 #define ITOPOFF_SHIFT		0
31 #define ITOPOFF_MASK		(0xF << ITOPOFF_SHIFT)
32 
33 struct charger_data {
34 	struct device *dev;
35 	struct max8997_dev *iodev;
36 	struct power_supply *battery;
37 	struct regulator *reg;
38 	struct extcon_dev *edev;
39 	struct notifier_block extcon_nb;
40 	struct work_struct extcon_work;
41 };
42 
43 static enum power_supply_property max8997_battery_props[] = {
44 	POWER_SUPPLY_PROP_STATUS, /* "FULL", "CHARGING" or "DISCHARGING". */
45 	POWER_SUPPLY_PROP_PRESENT, /* the presence of battery */
46 	POWER_SUPPLY_PROP_ONLINE, /* charger is active or not */
47 };
48 
49 /* Note that the charger control is done by a current regulator "CHARGER" */
50 static int max8997_battery_get_property(struct power_supply *psy,
51 		enum power_supply_property psp,
52 		union power_supply_propval *val)
53 {
54 	struct charger_data *charger = power_supply_get_drvdata(psy);
55 	struct i2c_client *i2c = charger->iodev->i2c;
56 	int ret;
57 	u8 reg;
58 
59 	switch (psp) {
60 	case POWER_SUPPLY_PROP_STATUS:
61 		val->intval = 0;
62 		ret = max8997_read_reg(i2c, MAX8997_REG_STATUS4, &reg);
63 		if (ret)
64 			return ret;
65 		if ((reg & (1 << 0)) == 0x1)
66 			val->intval = POWER_SUPPLY_STATUS_FULL;
67 		else if ((reg & DCINOK_MASK))
68 			val->intval = POWER_SUPPLY_STATUS_CHARGING;
69 		else
70 			val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
71 
72 		break;
73 	case POWER_SUPPLY_PROP_PRESENT:
74 		val->intval = 0;
75 		ret = max8997_read_reg(i2c, MAX8997_REG_STATUS4, &reg);
76 		if (ret)
77 			return ret;
78 		if ((reg & DETBAT_MASK) == 0x0)
79 			val->intval = 1;
80 
81 		break;
82 	case POWER_SUPPLY_PROP_ONLINE:
83 		val->intval = 0;
84 		ret = max8997_read_reg(i2c, MAX8997_REG_STATUS4, &reg);
85 		if (ret)
86 			return ret;
87 		if (reg & DCINOK_MASK)
88 			val->intval = 1;
89 
90 		break;
91 	default:
92 		return -EINVAL;
93 	}
94 
95 	return 0;
96 }
97 
98 static void max8997_battery_extcon_evt_worker(struct work_struct *work)
99 {
100 	struct charger_data *charger =
101 	    container_of(work, struct charger_data, extcon_work);
102 	struct extcon_dev *edev = charger->edev;
103 	int current_limit;
104 
105 	if (extcon_get_state(edev, EXTCON_CHG_USB_SDP) > 0) {
106 		dev_dbg(charger->dev, "USB SDP charger is connected\n");
107 		current_limit = 450000;
108 	} else if (extcon_get_state(edev, EXTCON_CHG_USB_DCP) > 0) {
109 		dev_dbg(charger->dev, "USB DCP charger is connected\n");
110 		current_limit = 650000;
111 	} else if (extcon_get_state(edev, EXTCON_CHG_USB_FAST) > 0) {
112 		dev_dbg(charger->dev, "USB FAST charger is connected\n");
113 		current_limit = 650000;
114 	} else if (extcon_get_state(edev, EXTCON_CHG_USB_SLOW) > 0) {
115 		dev_dbg(charger->dev, "USB SLOW charger is connected\n");
116 		current_limit = 650000;
117 	} else if (extcon_get_state(edev, EXTCON_CHG_USB_CDP) > 0) {
118 		dev_dbg(charger->dev, "USB CDP charger is connected\n");
119 		current_limit = 650000;
120 	} else {
121 		dev_dbg(charger->dev, "USB charger is disconnected\n");
122 		current_limit = -1;
123 	}
124 
125 	if (current_limit > 0) {
126 		int ret = regulator_set_current_limit(charger->reg, current_limit, current_limit);
127 
128 		if (ret) {
129 			dev_err(charger->dev, "failed to set current limit: %d\n", ret);
130 			return;
131 		}
132 		ret = regulator_enable(charger->reg);
133 		if (ret)
134 			dev_err(charger->dev, "failed to enable regulator: %d\n", ret);
135 	} else {
136 		int ret  = regulator_disable(charger->reg);
137 
138 		if (ret)
139 			dev_err(charger->dev, "failed to disable regulator: %d\n", ret);
140 	}
141 }
142 
143 static int max8997_battery_extcon_evt(struct notifier_block *nb,
144 				unsigned long event, void *param)
145 {
146 	struct charger_data *charger =
147 		container_of(nb, struct charger_data, extcon_nb);
148 	schedule_work(&charger->extcon_work);
149 	return NOTIFY_OK;
150 }
151 
152 static const struct power_supply_desc max8997_battery_desc = {
153 	.name		= "max8997_pmic",
154 	.type		= POWER_SUPPLY_TYPE_BATTERY,
155 	.get_property	= max8997_battery_get_property,
156 	.properties	= max8997_battery_props,
157 	.num_properties	= ARRAY_SIZE(max8997_battery_props),
158 };
159 
160 static int max8997_battery_probe(struct platform_device *pdev)
161 {
162 	int ret = 0;
163 	struct charger_data *charger;
164 	struct max8997_dev *iodev = dev_get_drvdata(pdev->dev.parent);
165 	struct device_node *np = pdev->dev.of_node;
166 	struct i2c_client *i2c = iodev->i2c;
167 	struct max8997_platform_data *pdata = iodev->pdata;
168 	struct power_supply_config psy_cfg = {};
169 
170 	if (!pdata) {
171 		dev_err(&pdev->dev, "No platform data supplied.\n");
172 		return -EINVAL;
173 	}
174 
175 	if (pdata->eoc_mA) {
176 		int val = (pdata->eoc_mA - 50) / 10;
177 		if (val < 0)
178 			val = 0;
179 		if (val > 0xf)
180 			val = 0xf;
181 
182 		ret = max8997_update_reg(i2c, MAX8997_REG_MBCCTRL5,
183 				val << ITOPOFF_SHIFT, ITOPOFF_MASK);
184 		if (ret < 0) {
185 			dev_err(&pdev->dev, "Cannot use i2c bus.\n");
186 			return ret;
187 		}
188 	}
189 	switch (pdata->timeout) {
190 	case 5:
191 		ret = max8997_update_reg(i2c, MAX8997_REG_MBCCTRL1,
192 				0x2 << TFCH_SHIFT, TFCH_MASK);
193 		break;
194 	case 6:
195 		ret = max8997_update_reg(i2c, MAX8997_REG_MBCCTRL1,
196 				0x3 << TFCH_SHIFT, TFCH_MASK);
197 		break;
198 	case 7:
199 		ret = max8997_update_reg(i2c, MAX8997_REG_MBCCTRL1,
200 				0x4 << TFCH_SHIFT, TFCH_MASK);
201 		break;
202 	case 0:
203 		ret = max8997_update_reg(i2c, MAX8997_REG_MBCCTRL1,
204 				0x7 << TFCH_SHIFT, TFCH_MASK);
205 		break;
206 	default:
207 		dev_err(&pdev->dev, "incorrect timeout value (%d)\n",
208 				pdata->timeout);
209 		return -EINVAL;
210 	}
211 	if (ret < 0) {
212 		dev_err(&pdev->dev, "Cannot use i2c bus.\n");
213 		return ret;
214 	}
215 
216 	charger = devm_kzalloc(&pdev->dev, sizeof(*charger), GFP_KERNEL);
217 	if (!charger)
218 		return -ENOMEM;
219 
220 	platform_set_drvdata(pdev, charger);
221 
222 	charger->dev = &pdev->dev;
223 	charger->iodev = iodev;
224 
225 	psy_cfg.drv_data = charger;
226 
227 	charger->battery = devm_power_supply_register(&pdev->dev,
228 						 &max8997_battery_desc,
229 						 &psy_cfg);
230 	if (IS_ERR(charger->battery)) {
231 		dev_err(&pdev->dev, "failed: power supply register\n");
232 		return PTR_ERR(charger->battery);
233 	}
234 
235 	// grab regulator from parent device's node
236 	pdev->dev.of_node = iodev->dev->of_node;
237 	charger->reg = devm_regulator_get_optional(&pdev->dev, "charger");
238 	pdev->dev.of_node = np;
239 	if (IS_ERR(charger->reg)) {
240 		if (PTR_ERR(charger->reg) == -EPROBE_DEFER)
241 			return -EPROBE_DEFER;
242 		dev_info(&pdev->dev, "couldn't get charger regulator\n");
243 	}
244 	charger->edev = extcon_get_extcon_dev("max8997-muic");
245 	if (IS_ERR(charger->edev)) {
246 		dev_err_probe(charger->dev, PTR_ERR(charger->edev),
247 			      "couldn't get extcon device: max8997-muic\n");
248 		return PTR_ERR(charger->edev);
249 	}
250 
251 	if (!IS_ERR(charger->reg) && !IS_ERR_OR_NULL(charger->edev)) {
252 		ret = devm_work_autocancel(&pdev->dev, &charger->extcon_work,
253 					   max8997_battery_extcon_evt_worker);
254 		if (ret) {
255 			dev_err(&pdev->dev, "failed to add extcon evt stop action: %d\n", ret);
256 			return ret;
257 		}
258 		charger->extcon_nb.notifier_call = max8997_battery_extcon_evt;
259 		ret = devm_extcon_register_notifier_all(&pdev->dev, charger->edev,
260 							&charger->extcon_nb);
261 		if (ret) {
262 			dev_err(&pdev->dev, "failed to register extcon notifier\n");
263 			return ret;
264 		}
265 	}
266 
267 	return 0;
268 }
269 
270 static const struct platform_device_id max8997_battery_id[] = {
271 	{ "max8997-battery", 0 },
272 	{ }
273 };
274 MODULE_DEVICE_TABLE(platform, max8997_battery_id);
275 
276 static struct platform_driver max8997_battery_driver = {
277 	.driver = {
278 		.name = "max8997-battery",
279 	},
280 	.probe = max8997_battery_probe,
281 	.id_table = max8997_battery_id,
282 };
283 module_platform_driver(max8997_battery_driver);
284 
285 MODULE_DESCRIPTION("MAXIM 8997/8966 battery control driver");
286 MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
287 MODULE_LICENSE("GPL");
288