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
29struct 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
40static enum power_supply_property tps65217_charger_props[] = {
41	POWER_SUPPLY_PROP_ONLINE,
42};
43
44static 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
78static 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
103static 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
116static 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
163static 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
175static 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
183static 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
256static 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
266static const struct of_device_id tps65217_charger_match_table[] = {
267	{ .compatible = "ti,tps65217-charger", },
268	{ /* sentinel */ }
269};
270MODULE_DEVICE_TABLE(of, tps65217_charger_match_table);
271
272static 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};
281module_platform_driver(tps65217_charger_driver);
282
283MODULE_LICENSE("GPL v2");
284MODULE_AUTHOR("Enric Balletbo Serra <enric.balletbo@collabora.com>");
285MODULE_DESCRIPTION("TPS65217 battery charger driver");
286