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 
39 struct 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 
50 static enum power_supply_property tps65090_ac_props[] = {
51 	POWER_SUPPLY_PROP_ONLINE,
52 };
53 
54 static 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 
71 static 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 
97 static 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 
134 static 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 
148 static 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 
197 static 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 
219 static 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 
231 static 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 
239 static 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 
335 fail_unregister_supply:
336 	power_supply_unregister(cdata->ac);
337 
338 	return ret;
339 }
340 
341 static 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 
352 static const struct of_device_id of_tps65090_charger_match[] = {
353 	{ .compatible = "ti,tps65090-charger", },
354 	{ /* end */ }
355 };
356 MODULE_DEVICE_TABLE(of, of_tps65090_charger_match);
357 
358 static struct platform_driver tps65090_charger_driver = {
359 	.driver	= {
360 		.name	= "tps65090-charger",
361 		.of_match_table = of_tps65090_charger_match,
362 	},
363 	.probe	= tps65090_charger_probe,
364 	.remove = tps65090_charger_remove,
365 };
366 module_platform_driver(tps65090_charger_driver);
367 
368 MODULE_LICENSE("GPL v2");
369 MODULE_AUTHOR("Syed Rafiuddin <srafiuddin@nvidia.com>");
370 MODULE_DESCRIPTION("tps65090 battery charger driver");
371