1 // SPDX-License-Identifier: GPL-2.0
2 // Battery charger driver for TI's tps65217
3 //
4 // Copyright (C) 2015 Collabora Ltd.
5 // Author: Enric Balletbo i Serra <enric.balletbo@collabora.com>
6 
7 /*
8  * Battery charger driver for TI's tps65217
9  */
10 #include <linux/kernel.h>
11 #include <linux/kthread.h>
12 #include <linux/device.h>
13 #include <linux/module.h>
14 #include <linux/platform_device.h>
15 #include <linux/init.h>
16 #include <linux/interrupt.h>
17 #include <linux/slab.h>
18 #include <linux/err.h>
19 #include <linux/of.h>
20 #include <linux/of_device.h>
21 #include <linux/power_supply.h>
22 
23 #include <linux/mfd/core.h>
24 #include <linux/mfd/tps65217.h>
25 
26 #define CHARGER_STATUS_PRESENT	(TPS65217_STATUS_ACPWR | TPS65217_STATUS_USBPWR)
27 #define NUM_CHARGER_IRQS	2
28 #define POLL_INTERVAL		(HZ * 2)
29 
30 struct tps65217_charger {
31 	struct tps65217 *tps;
32 	struct device *dev;
33 	struct power_supply *psy;
34 
35 	int	online;
36 	int	prev_online;
37 
38 	struct task_struct	*poll_task;
39 };
40 
41 static enum power_supply_property tps65217_charger_props[] = {
42 	POWER_SUPPLY_PROP_ONLINE,
43 };
44 
45 static int tps65217_config_charger(struct tps65217_charger *charger)
46 {
47 	int ret;
48 
49 	/*
50 	 * tps65217 rev. G, p. 31 (see p. 32 for NTC schematic)
51 	 *
52 	 * The device can be configured to support a 100k NTC (B = 3960) by
53 	 * setting the the NTC_TYPE bit in register CHGCONFIG1 to 1. However it
54 	 * is not recommended to do so. In sleep mode, the charger continues
55 	 * charging the battery, but all register values are reset to default
56 	 * values. Therefore, the charger would get the wrong temperature
57 	 * information. If 100k NTC setting is required, please contact the
58 	 * factory.
59 	 *
60 	 * ATTENTION, conflicting information, from p. 46
61 	 *
62 	 * NTC TYPE (for battery temperature measurement)
63 	 *   0 – 100k (curve 1, B = 3960)
64 	 *   1 – 10k  (curve 2, B = 3480) (default on reset)
65 	 *
66 	 */
67 	ret = tps65217_clear_bits(charger->tps, TPS65217_REG_CHGCONFIG1,
68 				  TPS65217_CHGCONFIG1_NTC_TYPE,
69 				  TPS65217_PROTECT_NONE);
70 	if (ret) {
71 		dev_err(charger->dev,
72 			"failed to set 100k NTC setting: %d\n", ret);
73 		return ret;
74 	}
75 
76 	return 0;
77 }
78 
79 static int tps65217_enable_charging(struct tps65217_charger *charger)
80 {
81 	int ret;
82 
83 	/* charger already enabled */
84 	if (charger->online)
85 		return 0;
86 
87 	dev_dbg(charger->dev, "%s: enable charging\n", __func__);
88 	ret = tps65217_set_bits(charger->tps, TPS65217_REG_CHGCONFIG1,
89 				TPS65217_CHGCONFIG1_CHG_EN,
90 				TPS65217_CHGCONFIG1_CHG_EN,
91 				TPS65217_PROTECT_NONE);
92 	if (ret) {
93 		dev_err(charger->dev,
94 			"%s: Error in writing CHG_EN in reg 0x%x: %d\n",
95 			__func__, TPS65217_REG_CHGCONFIG1, ret);
96 		return ret;
97 	}
98 
99 	charger->online = 1;
100 
101 	return 0;
102 }
103 
104 static int tps65217_charger_get_property(struct power_supply *psy,
105 					 enum power_supply_property psp,
106 					 union power_supply_propval *val)
107 {
108 	struct tps65217_charger *charger = power_supply_get_drvdata(psy);
109 
110 	if (psp == POWER_SUPPLY_PROP_ONLINE) {
111 		val->intval = charger->online;
112 		return 0;
113 	}
114 	return -EINVAL;
115 }
116 
117 static irqreturn_t tps65217_charger_irq(int irq, void *dev)
118 {
119 	int ret, val;
120 	struct tps65217_charger *charger = dev;
121 
122 	charger->prev_online = charger->online;
123 
124 	ret = tps65217_reg_read(charger->tps, TPS65217_REG_STATUS, &val);
125 	if (ret < 0) {
126 		dev_err(charger->dev, "%s: Error in reading reg 0x%x\n",
127 			__func__, TPS65217_REG_STATUS);
128 		return IRQ_HANDLED;
129 	}
130 
131 	dev_dbg(charger->dev, "%s: 0x%x\n", __func__, val);
132 
133 	/* check for charger status bit */
134 	if (val & CHARGER_STATUS_PRESENT) {
135 		ret = tps65217_enable_charging(charger);
136 		if (ret) {
137 			dev_err(charger->dev,
138 				"failed to enable charger: %d\n", ret);
139 			return IRQ_HANDLED;
140 		}
141 	} else {
142 		charger->online = 0;
143 	}
144 
145 	if (charger->prev_online != charger->online)
146 		power_supply_changed(charger->psy);
147 
148 	ret = tps65217_reg_read(charger->tps, TPS65217_REG_CHGCONFIG0, &val);
149 	if (ret < 0) {
150 		dev_err(charger->dev, "%s: Error in reading reg 0x%x\n",
151 			__func__, TPS65217_REG_CHGCONFIG0);
152 		return IRQ_HANDLED;
153 	}
154 
155 	if (val & TPS65217_CHGCONFIG0_ACTIVE)
156 		dev_dbg(charger->dev, "%s: charger is charging\n", __func__);
157 	else
158 		dev_dbg(charger->dev,
159 			"%s: charger is NOT charging\n", __func__);
160 
161 	return IRQ_HANDLED;
162 }
163 
164 static int tps65217_charger_poll_task(void *data)
165 {
166 	set_freezable();
167 
168 	while (!kthread_should_stop()) {
169 		schedule_timeout_interruptible(POLL_INTERVAL);
170 		try_to_freeze();
171 		tps65217_charger_irq(-1, data);
172 	}
173 	return 0;
174 }
175 
176 static const struct power_supply_desc tps65217_charger_desc = {
177 	.name			= "tps65217-charger",
178 	.type			= POWER_SUPPLY_TYPE_MAINS,
179 	.get_property		= tps65217_charger_get_property,
180 	.properties		= tps65217_charger_props,
181 	.num_properties		= ARRAY_SIZE(tps65217_charger_props),
182 };
183 
184 static int tps65217_charger_probe(struct platform_device *pdev)
185 {
186 	struct tps65217 *tps = dev_get_drvdata(pdev->dev.parent);
187 	struct tps65217_charger *charger;
188 	struct power_supply_config cfg = {};
189 	struct task_struct *poll_task;
190 	int irq[NUM_CHARGER_IRQS];
191 	int ret;
192 	int i;
193 
194 	charger = devm_kzalloc(&pdev->dev, sizeof(*charger), GFP_KERNEL);
195 	if (!charger)
196 		return -ENOMEM;
197 
198 	platform_set_drvdata(pdev, charger);
199 	charger->tps = tps;
200 	charger->dev = &pdev->dev;
201 
202 	cfg.of_node = pdev->dev.of_node;
203 	cfg.drv_data = charger;
204 
205 	charger->psy = devm_power_supply_register(&pdev->dev,
206 						  &tps65217_charger_desc,
207 						  &cfg);
208 	if (IS_ERR(charger->psy)) {
209 		dev_err(&pdev->dev, "failed: power supply register\n");
210 		return PTR_ERR(charger->psy);
211 	}
212 
213 	irq[0] = platform_get_irq_byname(pdev, "USB");
214 	irq[1] = platform_get_irq_byname(pdev, "AC");
215 
216 	ret = tps65217_config_charger(charger);
217 	if (ret < 0) {
218 		dev_err(charger->dev, "charger config failed, err %d\n", ret);
219 		return ret;
220 	}
221 
222 	/* Create a polling thread if an interrupt is invalid */
223 	if (irq[0] < 0 || irq[1] < 0) {
224 		poll_task = kthread_run(tps65217_charger_poll_task,
225 					charger, "ktps65217charger");
226 		if (IS_ERR(poll_task)) {
227 			ret = PTR_ERR(poll_task);
228 			dev_err(charger->dev,
229 				"Unable to run kthread err %d\n", ret);
230 			return ret;
231 		}
232 
233 		charger->poll_task = poll_task;
234 		return 0;
235 	}
236 
237 	/* Create IRQ threads for charger interrupts */
238 	for (i = 0; i < NUM_CHARGER_IRQS; i++) {
239 		ret = devm_request_threaded_irq(&pdev->dev, irq[i], NULL,
240 						tps65217_charger_irq,
241 						0, "tps65217-charger",
242 						charger);
243 		if (ret) {
244 			dev_err(charger->dev,
245 				"Unable to register irq %d err %d\n", irq[i],
246 				ret);
247 			return ret;
248 		}
249 
250 		/* Check current state */
251 		tps65217_charger_irq(-1, charger);
252 	}
253 
254 	return 0;
255 }
256 
257 static int tps65217_charger_remove(struct platform_device *pdev)
258 {
259 	struct tps65217_charger *charger = platform_get_drvdata(pdev);
260 
261 	if (charger->poll_task)
262 		kthread_stop(charger->poll_task);
263 
264 	return 0;
265 }
266 
267 static const struct of_device_id tps65217_charger_match_table[] = {
268 	{ .compatible = "ti,tps65217-charger", },
269 	{ /* sentinel */ }
270 };
271 MODULE_DEVICE_TABLE(of, tps65217_charger_match_table);
272 
273 static struct platform_driver tps65217_charger_driver = {
274 	.probe	= tps65217_charger_probe,
275 	.remove = tps65217_charger_remove,
276 	.driver	= {
277 		.name	= "tps65217-charger",
278 		.of_match_table = of_match_ptr(tps65217_charger_match_table),
279 	},
280 
281 };
282 module_platform_driver(tps65217_charger_driver);
283 
284 MODULE_LICENSE("GPL v2");
285 MODULE_AUTHOR("Enric Balletbo Serra <enric.balletbo@collabora.com>");
286 MODULE_DESCRIPTION("TPS65217 battery charger driver");
287