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