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
30 struct 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
41 static enum power_supply_property tps65217_charger_props[] = {
42 POWER_SUPPLY_PROP_ONLINE,
43 };
44
tps65217_config_charger(struct tps65217_charger * charger)45 static 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
tps65217_enable_charging(struct tps65217_charger * charger)79 static 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
tps65217_charger_get_property(struct power_supply * psy,enum power_supply_property psp,union power_supply_propval * val)104 static 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
tps65217_charger_irq(int irq,void * dev)117 static 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
tps65217_charger_poll_task(void * data)164 static 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
176 static 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
tps65217_charger_probe(struct platform_device * pdev)184 static 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
tps65217_charger_remove(struct platform_device * pdev)257 static 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
267 static const struct of_device_id tps65217_charger_match_table[] = {
268 { .compatible = "ti,tps65217-charger", },
269 { /* sentinel */ }
270 };
271 MODULE_DEVICE_TABLE(of, tps65217_charger_match_table);
272
273 static 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 };
282 module_platform_driver(tps65217_charger_driver);
283
284 MODULE_LICENSE("GPL v2");
285 MODULE_AUTHOR("Enric Balletbo Serra <enric.balletbo@collabora.com>");
286 MODULE_DESCRIPTION("TPS65217 battery charger driver");
287