1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Battery charger driver for TI's tps65090
4  *
5  * Copyright (c) 2013, NVIDIA CORPORATION.  All rights reserved.
6 
7  */
8 #include <linux/delay.h>
9 #include <linux/err.h>
10 #include <linux/freezer.h>
11 #include <linux/init.h>
12 #include <linux/interrupt.h>
13 #include <linux/kernel.h>
14 #include <linux/kthread.h>
15 #include <linux/module.h>
16 #include <linux/of.h>
17 #include <linux/platform_device.h>
18 #include <linux/power_supply.h>
19 #include <linux/slab.h>
20 
21 #include <linux/mfd/tps65090.h>
22 
23 #define TPS65090_CHARGER_ENABLE	BIT(0)
24 #define TPS65090_VACG		BIT(1)
25 #define TPS65090_NOITERM	BIT(5)
26 
27 #define POLL_INTERVAL		(HZ * 2)	/* Used when no irq */
28 
29 struct tps65090_charger {
30 	struct	device	*dev;
31 	int	ac_online;
32 	int	prev_ac_online;
33 	int	irq;
34 	struct task_struct	*poll_task;
35 	bool			passive_mode;
36 	struct power_supply	*ac;
37 	struct tps65090_platform_data *pdata;
38 };
39 
40 static enum power_supply_property tps65090_ac_props[] = {
41 	POWER_SUPPLY_PROP_ONLINE,
42 };
43 
44 static int tps65090_low_chrg_current(struct tps65090_charger *charger)
45 {
46 	int ret;
47 
48 	if (charger->passive_mode)
49 		return 0;
50 
51 	ret = tps65090_write(charger->dev->parent, TPS65090_REG_CG_CTRL5,
52 			TPS65090_NOITERM);
53 	if (ret < 0) {
54 		dev_err(charger->dev, "%s(): error reading in register 0x%x\n",
55 			__func__, TPS65090_REG_CG_CTRL5);
56 		return ret;
57 	}
58 	return 0;
59 }
60 
61 static int tps65090_enable_charging(struct tps65090_charger *charger)
62 {
63 	int ret;
64 	uint8_t ctrl0 = 0;
65 
66 	if (charger->passive_mode)
67 		return 0;
68 
69 	ret = tps65090_read(charger->dev->parent, TPS65090_REG_CG_CTRL0,
70 			    &ctrl0);
71 	if (ret < 0) {
72 		dev_err(charger->dev, "%s(): error reading in register 0x%x\n",
73 				__func__, TPS65090_REG_CG_CTRL0);
74 		return ret;
75 	}
76 
77 	ret = tps65090_write(charger->dev->parent, TPS65090_REG_CG_CTRL0,
78 				(ctrl0 | TPS65090_CHARGER_ENABLE));
79 	if (ret < 0) {
80 		dev_err(charger->dev, "%s(): error writing in register 0x%x\n",
81 				__func__, TPS65090_REG_CG_CTRL0);
82 		return ret;
83 	}
84 	return 0;
85 }
86 
87 static int tps65090_config_charger(struct tps65090_charger *charger)
88 {
89 	uint8_t intrmask = 0;
90 	int ret;
91 
92 	if (charger->passive_mode)
93 		return 0;
94 
95 	if (charger->pdata->enable_low_current_chrg) {
96 		ret = tps65090_low_chrg_current(charger);
97 		if (ret < 0) {
98 			dev_err(charger->dev,
99 				"error configuring low charge current\n");
100 			return ret;
101 		}
102 	}
103 
104 	/* Enable the VACG interrupt for AC power detect */
105 	ret = tps65090_read(charger->dev->parent, TPS65090_REG_INTR_MASK,
106 			    &intrmask);
107 	if (ret < 0) {
108 		dev_err(charger->dev, "%s(): error reading in register 0x%x\n",
109 			__func__, TPS65090_REG_INTR_MASK);
110 		return ret;
111 	}
112 
113 	ret = tps65090_write(charger->dev->parent, TPS65090_REG_INTR_MASK,
114 			     (intrmask | TPS65090_VACG));
115 	if (ret < 0) {
116 		dev_err(charger->dev, "%s(): error writing in register 0x%x\n",
117 			__func__, TPS65090_REG_CG_CTRL0);
118 		return ret;
119 	}
120 
121 	return 0;
122 }
123 
124 static int tps65090_ac_get_property(struct power_supply *psy,
125 			enum power_supply_property psp,
126 			union power_supply_propval *val)
127 {
128 	struct tps65090_charger *charger = power_supply_get_drvdata(psy);
129 
130 	if (psp == POWER_SUPPLY_PROP_ONLINE) {
131 		val->intval = charger->ac_online;
132 		charger->prev_ac_online = charger->ac_online;
133 		return 0;
134 	}
135 	return -EINVAL;
136 }
137 
138 static irqreturn_t tps65090_charger_isr(int irq, void *dev_id)
139 {
140 	struct tps65090_charger *charger = dev_id;
141 	int ret;
142 	uint8_t status1 = 0;
143 	uint8_t intrsts = 0;
144 
145 	ret = tps65090_read(charger->dev->parent, TPS65090_REG_CG_STATUS1,
146 			    &status1);
147 	if (ret < 0) {
148 		dev_err(charger->dev, "%s(): Error in reading reg 0x%x\n",
149 				__func__, TPS65090_REG_CG_STATUS1);
150 		return IRQ_HANDLED;
151 	}
152 	msleep(75);
153 	ret = tps65090_read(charger->dev->parent, TPS65090_REG_INTR_STS,
154 			    &intrsts);
155 	if (ret < 0) {
156 		dev_err(charger->dev, "%s(): Error in reading reg 0x%x\n",
157 				__func__, TPS65090_REG_INTR_STS);
158 		return IRQ_HANDLED;
159 	}
160 
161 	if (intrsts & TPS65090_VACG) {
162 		ret = tps65090_enable_charging(charger);
163 		if (ret < 0)
164 			return IRQ_HANDLED;
165 		charger->ac_online = 1;
166 	} else {
167 		charger->ac_online = 0;
168 	}
169 
170 	/* Clear interrupts. */
171 	if (!charger->passive_mode) {
172 		ret = tps65090_write(charger->dev->parent,
173 				     TPS65090_REG_INTR_STS, 0x00);
174 		if (ret < 0) {
175 			dev_err(charger->dev,
176 				"%s(): Error in writing reg 0x%x\n",
177 				__func__, TPS65090_REG_INTR_STS);
178 		}
179 	}
180 
181 	if (charger->prev_ac_online != charger->ac_online)
182 		power_supply_changed(charger->ac);
183 
184 	return IRQ_HANDLED;
185 }
186 
187 static struct tps65090_platform_data *
188 		tps65090_parse_dt_charger_data(struct platform_device *pdev)
189 {
190 	struct tps65090_platform_data *pdata;
191 	struct device_node *np = pdev->dev.of_node;
192 	unsigned int prop;
193 
194 	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
195 	if (!pdata) {
196 		dev_err(&pdev->dev, "Memory alloc for tps65090_pdata failed\n");
197 		return NULL;
198 	}
199 
200 	prop = of_property_read_bool(np, "ti,enable-low-current-chrg");
201 	pdata->enable_low_current_chrg = prop;
202 
203 	pdata->irq_base = -1;
204 
205 	return pdata;
206 
207 }
208 
209 static int tps65090_charger_poll_task(void *data)
210 {
211 	set_freezable();
212 
213 	while (!kthread_should_stop()) {
214 		schedule_timeout_interruptible(POLL_INTERVAL);
215 		try_to_freeze();
216 		tps65090_charger_isr(-1, data);
217 	}
218 	return 0;
219 }
220 
221 static const struct power_supply_desc tps65090_charger_desc = {
222 	.name			= "tps65090-ac",
223 	.type			= POWER_SUPPLY_TYPE_MAINS,
224 	.get_property		= tps65090_ac_get_property,
225 	.properties		= tps65090_ac_props,
226 	.num_properties		= ARRAY_SIZE(tps65090_ac_props),
227 };
228 
229 static int tps65090_charger_probe(struct platform_device *pdev)
230 {
231 	struct tps65090_charger *cdata;
232 	struct tps65090_platform_data *pdata;
233 	struct power_supply_config psy_cfg = {};
234 	uint8_t status1 = 0;
235 	int ret;
236 	int irq;
237 
238 	pdata = dev_get_platdata(pdev->dev.parent);
239 
240 	if (IS_ENABLED(CONFIG_OF) && !pdata && pdev->dev.of_node)
241 		pdata = tps65090_parse_dt_charger_data(pdev);
242 
243 	if (!pdata) {
244 		dev_err(&pdev->dev, "%s():no platform data available\n",
245 				__func__);
246 		return -ENODEV;
247 	}
248 
249 	cdata = devm_kzalloc(&pdev->dev, sizeof(*cdata), GFP_KERNEL);
250 	if (!cdata) {
251 		dev_err(&pdev->dev, "failed to allocate memory status\n");
252 		return -ENOMEM;
253 	}
254 
255 	platform_set_drvdata(pdev, cdata);
256 
257 	cdata->dev			= &pdev->dev;
258 	cdata->pdata			= pdata;
259 
260 	psy_cfg.supplied_to		= pdata->supplied_to;
261 	psy_cfg.num_supplicants		= pdata->num_supplicants;
262 	psy_cfg.of_node			= pdev->dev.of_node;
263 	psy_cfg.drv_data		= cdata;
264 
265 	cdata->ac = power_supply_register(&pdev->dev, &tps65090_charger_desc,
266 			&psy_cfg);
267 	if (IS_ERR(cdata->ac)) {
268 		dev_err(&pdev->dev, "failed: power supply register\n");
269 		return PTR_ERR(cdata->ac);
270 	}
271 
272 	irq = platform_get_irq(pdev, 0);
273 	if (irq < 0)
274 		irq = -ENXIO;
275 	cdata->irq = irq;
276 
277 	ret = tps65090_config_charger(cdata);
278 	if (ret < 0) {
279 		dev_err(&pdev->dev, "charger config failed, err %d\n", ret);
280 		goto fail_unregister_supply;
281 	}
282 
283 	/* Check for charger presence */
284 	ret = tps65090_read(cdata->dev->parent, TPS65090_REG_CG_STATUS1,
285 			&status1);
286 	if (ret < 0) {
287 		dev_err(cdata->dev, "%s(): Error in reading reg 0x%x", __func__,
288 			TPS65090_REG_CG_STATUS1);
289 		goto fail_unregister_supply;
290 	}
291 
292 	if (status1 != 0) {
293 		ret = tps65090_enable_charging(cdata);
294 		if (ret < 0) {
295 			dev_err(cdata->dev, "error enabling charger\n");
296 			goto fail_unregister_supply;
297 		}
298 		cdata->ac_online = 1;
299 		power_supply_changed(cdata->ac);
300 	}
301 
302 	if (irq != -ENXIO) {
303 		ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
304 			tps65090_charger_isr, IRQF_ONESHOT, "tps65090-charger", cdata);
305 		if (ret) {
306 			dev_err(cdata->dev,
307 				"Unable to register irq %d err %d\n", irq,
308 				ret);
309 			goto fail_unregister_supply;
310 		}
311 	} else {
312 		cdata->poll_task = kthread_run(tps65090_charger_poll_task,
313 					      cdata, "ktps65090charger");
314 		cdata->passive_mode = true;
315 		if (IS_ERR(cdata->poll_task)) {
316 			ret = PTR_ERR(cdata->poll_task);
317 			dev_err(cdata->dev,
318 				"Unable to run kthread err %d\n", ret);
319 			goto fail_unregister_supply;
320 		}
321 	}
322 
323 	return 0;
324 
325 fail_unregister_supply:
326 	power_supply_unregister(cdata->ac);
327 
328 	return ret;
329 }
330 
331 static int tps65090_charger_remove(struct platform_device *pdev)
332 {
333 	struct tps65090_charger *cdata = platform_get_drvdata(pdev);
334 
335 	if (cdata->irq == -ENXIO)
336 		kthread_stop(cdata->poll_task);
337 	power_supply_unregister(cdata->ac);
338 
339 	return 0;
340 }
341 
342 static const struct of_device_id of_tps65090_charger_match[] = {
343 	{ .compatible = "ti,tps65090-charger", },
344 	{ /* end */ }
345 };
346 MODULE_DEVICE_TABLE(of, of_tps65090_charger_match);
347 
348 static struct platform_driver tps65090_charger_driver = {
349 	.driver	= {
350 		.name	= "tps65090-charger",
351 		.of_match_table = of_tps65090_charger_match,
352 	},
353 	.probe	= tps65090_charger_probe,
354 	.remove = tps65090_charger_remove,
355 };
356 module_platform_driver(tps65090_charger_driver);
357 
358 MODULE_LICENSE("GPL v2");
359 MODULE_AUTHOR("Syed Rafiuddin <srafiuddin@nvidia.com>");
360 MODULE_DESCRIPTION("tps65090 battery charger driver");
361