1/*
2 * Battery charger driver for TI's tps65090
3 *
4 * Copyright (c) 2013, NVIDIA CORPORATION.  All rights reserved.
5
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms and conditions of the GNU General Public License,
8 * version 2, as published by the Free Software Foundation.
9
10 * This program is distributed in the hope it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
13 * more details.
14
15 * You should have received a copy of the GNU General Public License
16 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
17 */
18#include <linux/delay.h>
19#include <linux/err.h>
20#include <linux/freezer.h>
21#include <linux/init.h>
22#include <linux/interrupt.h>
23#include <linux/kernel.h>
24#include <linux/kthread.h>
25#include <linux/module.h>
26#include <linux/of_device.h>
27#include <linux/platform_device.h>
28#include <linux/power_supply.h>
29#include <linux/slab.h>
30
31#include <linux/mfd/tps65090.h>
32
33#define TPS65090_CHARGER_ENABLE	BIT(0)
34#define TPS65090_VACG		BIT(1)
35#define TPS65090_NOITERM	BIT(5)
36
37#define POLL_INTERVAL		(HZ * 2)	/* Used when no irq */
38
39struct tps65090_charger {
40	struct	device	*dev;
41	int	ac_online;
42	int	prev_ac_online;
43	int	irq;
44	struct task_struct	*poll_task;
45	bool			passive_mode;
46	struct power_supply	*ac;
47	struct tps65090_platform_data *pdata;
48};
49
50static enum power_supply_property tps65090_ac_props[] = {
51	POWER_SUPPLY_PROP_ONLINE,
52};
53
54static int tps65090_low_chrg_current(struct tps65090_charger *charger)
55{
56	int ret;
57
58	if (charger->passive_mode)
59		return 0;
60
61	ret = tps65090_write(charger->dev->parent, TPS65090_REG_CG_CTRL5,
62			TPS65090_NOITERM);
63	if (ret < 0) {
64		dev_err(charger->dev, "%s(): error reading in register 0x%x\n",
65			__func__, TPS65090_REG_CG_CTRL5);
66		return ret;
67	}
68	return 0;
69}
70
71static int tps65090_enable_charging(struct tps65090_charger *charger)
72{
73	int ret;
74	uint8_t ctrl0 = 0;
75
76	if (charger->passive_mode)
77		return 0;
78
79	ret = tps65090_read(charger->dev->parent, TPS65090_REG_CG_CTRL0,
80			    &ctrl0);
81	if (ret < 0) {
82		dev_err(charger->dev, "%s(): error reading in register 0x%x\n",
83				__func__, TPS65090_REG_CG_CTRL0);
84		return ret;
85	}
86
87	ret = tps65090_write(charger->dev->parent, TPS65090_REG_CG_CTRL0,
88				(ctrl0 | TPS65090_CHARGER_ENABLE));
89	if (ret < 0) {
90		dev_err(charger->dev, "%s(): error writing in register 0x%x\n",
91				__func__, TPS65090_REG_CG_CTRL0);
92		return ret;
93	}
94	return 0;
95}
96
97static int tps65090_config_charger(struct tps65090_charger *charger)
98{
99	uint8_t intrmask = 0;
100	int ret;
101
102	if (charger->passive_mode)
103		return 0;
104
105	if (charger->pdata->enable_low_current_chrg) {
106		ret = tps65090_low_chrg_current(charger);
107		if (ret < 0) {
108			dev_err(charger->dev,
109				"error configuring low charge current\n");
110			return ret;
111		}
112	}
113
114	/* Enable the VACG interrupt for AC power detect */
115	ret = tps65090_read(charger->dev->parent, TPS65090_REG_INTR_MASK,
116			    &intrmask);
117	if (ret < 0) {
118		dev_err(charger->dev, "%s(): error reading in register 0x%x\n",
119			__func__, TPS65090_REG_INTR_MASK);
120		return ret;
121	}
122
123	ret = tps65090_write(charger->dev->parent, TPS65090_REG_INTR_MASK,
124			     (intrmask | TPS65090_VACG));
125	if (ret < 0) {
126		dev_err(charger->dev, "%s(): error writing in register 0x%x\n",
127			__func__, TPS65090_REG_CG_CTRL0);
128		return ret;
129	}
130
131	return 0;
132}
133
134static int tps65090_ac_get_property(struct power_supply *psy,
135			enum power_supply_property psp,
136			union power_supply_propval *val)
137{
138	struct tps65090_charger *charger = power_supply_get_drvdata(psy);
139
140	if (psp == POWER_SUPPLY_PROP_ONLINE) {
141		val->intval = charger->ac_online;
142		charger->prev_ac_online = charger->ac_online;
143		return 0;
144	}
145	return -EINVAL;
146}
147
148static irqreturn_t tps65090_charger_isr(int irq, void *dev_id)
149{
150	struct tps65090_charger *charger = dev_id;
151	int ret;
152	uint8_t status1 = 0;
153	uint8_t intrsts = 0;
154
155	ret = tps65090_read(charger->dev->parent, TPS65090_REG_CG_STATUS1,
156			    &status1);
157	if (ret < 0) {
158		dev_err(charger->dev, "%s(): Error in reading reg 0x%x\n",
159				__func__, TPS65090_REG_CG_STATUS1);
160		return IRQ_HANDLED;
161	}
162	msleep(75);
163	ret = tps65090_read(charger->dev->parent, TPS65090_REG_INTR_STS,
164			    &intrsts);
165	if (ret < 0) {
166		dev_err(charger->dev, "%s(): Error in reading reg 0x%x\n",
167				__func__, TPS65090_REG_INTR_STS);
168		return IRQ_HANDLED;
169	}
170
171	if (intrsts & TPS65090_VACG) {
172		ret = tps65090_enable_charging(charger);
173		if (ret < 0)
174			return IRQ_HANDLED;
175		charger->ac_online = 1;
176	} else {
177		charger->ac_online = 0;
178	}
179
180	/* Clear interrupts. */
181	if (!charger->passive_mode) {
182		ret = tps65090_write(charger->dev->parent,
183				     TPS65090_REG_INTR_STS, 0x00);
184		if (ret < 0) {
185			dev_err(charger->dev,
186				"%s(): Error in writing reg 0x%x\n",
187				__func__, TPS65090_REG_INTR_STS);
188		}
189	}
190
191	if (charger->prev_ac_online != charger->ac_online)
192		power_supply_changed(charger->ac);
193
194	return IRQ_HANDLED;
195}
196
197static struct tps65090_platform_data *
198		tps65090_parse_dt_charger_data(struct platform_device *pdev)
199{
200	struct tps65090_platform_data *pdata;
201	struct device_node *np = pdev->dev.of_node;
202	unsigned int prop;
203
204	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
205	if (!pdata) {
206		dev_err(&pdev->dev, "Memory alloc for tps65090_pdata failed\n");
207		return NULL;
208	}
209
210	prop = of_property_read_bool(np, "ti,enable-low-current-chrg");
211	pdata->enable_low_current_chrg = prop;
212
213	pdata->irq_base = -1;
214
215	return pdata;
216
217}
218
219static int tps65090_charger_poll_task(void *data)
220{
221	set_freezable();
222
223	while (!kthread_should_stop()) {
224		schedule_timeout_interruptible(POLL_INTERVAL);
225		try_to_freeze();
226		tps65090_charger_isr(-1, data);
227	}
228	return 0;
229}
230
231static const struct power_supply_desc tps65090_charger_desc = {
232	.name			= "tps65090-ac",
233	.type			= POWER_SUPPLY_TYPE_MAINS,
234	.get_property		= tps65090_ac_get_property,
235	.properties		= tps65090_ac_props,
236	.num_properties		= ARRAY_SIZE(tps65090_ac_props),
237};
238
239static int tps65090_charger_probe(struct platform_device *pdev)
240{
241	struct tps65090_charger *cdata;
242	struct tps65090_platform_data *pdata;
243	struct power_supply_config psy_cfg = {};
244	uint8_t status1 = 0;
245	int ret;
246	int irq;
247
248	pdata = dev_get_platdata(pdev->dev.parent);
249
250	if (IS_ENABLED(CONFIG_OF) && !pdata && pdev->dev.of_node)
251		pdata = tps65090_parse_dt_charger_data(pdev);
252
253	if (!pdata) {
254		dev_err(&pdev->dev, "%s():no platform data available\n",
255				__func__);
256		return -ENODEV;
257	}
258
259	cdata = devm_kzalloc(&pdev->dev, sizeof(*cdata), GFP_KERNEL);
260	if (!cdata) {
261		dev_err(&pdev->dev, "failed to allocate memory status\n");
262		return -ENOMEM;
263	}
264
265	platform_set_drvdata(pdev, cdata);
266
267	cdata->dev			= &pdev->dev;
268	cdata->pdata			= pdata;
269
270	psy_cfg.supplied_to		= pdata->supplied_to;
271	psy_cfg.num_supplicants		= pdata->num_supplicants;
272	psy_cfg.of_node			= pdev->dev.of_node;
273	psy_cfg.drv_data		= cdata;
274
275	cdata->ac = power_supply_register(&pdev->dev, &tps65090_charger_desc,
276			&psy_cfg);
277	if (IS_ERR(cdata->ac)) {
278		dev_err(&pdev->dev, "failed: power supply register\n");
279		return PTR_ERR(cdata->ac);
280	}
281
282	irq = platform_get_irq(pdev, 0);
283	if (irq < 0)
284		irq = -ENXIO;
285	cdata->irq = irq;
286
287	ret = tps65090_config_charger(cdata);
288	if (ret < 0) {
289		dev_err(&pdev->dev, "charger config failed, err %d\n", ret);
290		goto fail_unregister_supply;
291	}
292
293	/* Check for charger presence */
294	ret = tps65090_read(cdata->dev->parent, TPS65090_REG_CG_STATUS1,
295			&status1);
296	if (ret < 0) {
297		dev_err(cdata->dev, "%s(): Error in reading reg 0x%x", __func__,
298			TPS65090_REG_CG_STATUS1);
299		goto fail_unregister_supply;
300	}
301
302	if (status1 != 0) {
303		ret = tps65090_enable_charging(cdata);
304		if (ret < 0) {
305			dev_err(cdata->dev, "error enabling charger\n");
306			goto fail_unregister_supply;
307		}
308		cdata->ac_online = 1;
309		power_supply_changed(cdata->ac);
310	}
311
312	if (irq != -ENXIO) {
313		ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
314			tps65090_charger_isr, 0, "tps65090-charger", cdata);
315		if (ret) {
316			dev_err(cdata->dev,
317				"Unable to register irq %d err %d\n", irq,
318				ret);
319			goto fail_unregister_supply;
320		}
321	} else {
322		cdata->poll_task = kthread_run(tps65090_charger_poll_task,
323					      cdata, "ktps65090charger");
324		cdata->passive_mode = true;
325		if (IS_ERR(cdata->poll_task)) {
326			ret = PTR_ERR(cdata->poll_task);
327			dev_err(cdata->dev,
328				"Unable to run kthread err %d\n", ret);
329			goto fail_unregister_supply;
330		}
331	}
332
333	return 0;
334
335fail_unregister_supply:
336	power_supply_unregister(cdata->ac);
337
338	return ret;
339}
340
341static int tps65090_charger_remove(struct platform_device *pdev)
342{
343	struct tps65090_charger *cdata = platform_get_drvdata(pdev);
344
345	if (cdata->irq == -ENXIO)
346		kthread_stop(cdata->poll_task);
347	power_supply_unregister(cdata->ac);
348
349	return 0;
350}
351
352static const struct of_device_id of_tps65090_charger_match[] = {
353	{ .compatible = "ti,tps65090-charger", },
354	{ /* end */ }
355};
356
357static struct platform_driver tps65090_charger_driver = {
358	.driver	= {
359		.name	= "tps65090-charger",
360		.of_match_table = of_tps65090_charger_match,
361	},
362	.probe	= tps65090_charger_probe,
363	.remove = tps65090_charger_remove,
364};
365module_platform_driver(tps65090_charger_driver);
366
367MODULE_LICENSE("GPL v2");
368MODULE_AUTHOR("Syed Rafiuddin <srafiuddin@nvidia.com>");
369MODULE_DESCRIPTION("tps65090 battery charger driver");
370