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
30struct 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
41static enum power_supply_property tps65217_charger_props[] = {
42	POWER_SUPPLY_PROP_ONLINE,
43};
44
45static 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
79static 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
104static 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
117static 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
164static 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
176static 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
184static 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						IRQF_ONESHOT, "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
257static 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
267static const struct of_device_id tps65217_charger_match_table[] = {
268	{ .compatible = "ti,tps65217-charger", },
269	{ /* sentinel */ }
270};
271MODULE_DEVICE_TABLE(of, tps65217_charger_match_table);
272
273static 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};
282module_platform_driver(tps65217_charger_driver);
283
284MODULE_LICENSE("GPL v2");
285MODULE_AUTHOR("Enric Balletbo Serra <enric.balletbo@collabora.com>");
286MODULE_DESCRIPTION("TPS65217 battery charger driver");
287