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/power_supply.h>
21
22 #include <linux/mfd/core.h>
23 #include <linux/mfd/tps65217.h>
24
25 #define CHARGER_STATUS_PRESENT (TPS65217_STATUS_ACPWR | TPS65217_STATUS_USBPWR)
26 #define NUM_CHARGER_IRQS 2
27 #define POLL_INTERVAL (HZ * 2)
28
29 struct tps65217_charger {
30 struct tps65217 *tps;
31 struct device *dev;
32 struct power_supply *psy;
33
34 int online;
35 int prev_online;
36
37 struct task_struct *poll_task;
38 };
39
40 static enum power_supply_property tps65217_charger_props[] = {
41 POWER_SUPPLY_PROP_ONLINE,
42 };
43
tps65217_config_charger(struct tps65217_charger * charger)44 static int tps65217_config_charger(struct tps65217_charger *charger)
45 {
46 int ret;
47
48 /*
49 * tps65217 rev. G, p. 31 (see p. 32 for NTC schematic)
50 *
51 * The device can be configured to support a 100k NTC (B = 3960) by
52 * setting the NTC_TYPE bit in register CHGCONFIG1 to 1. However it
53 * is not recommended to do so. In sleep mode, the charger continues
54 * charging the battery, but all register values are reset to default
55 * values. Therefore, the charger would get the wrong temperature
56 * information. If 100k NTC setting is required, please contact the
57 * factory.
58 *
59 * ATTENTION, conflicting information, from p. 46
60 *
61 * NTC TYPE (for battery temperature measurement)
62 * 0 – 100k (curve 1, B = 3960)
63 * 1 – 10k (curve 2, B = 3480) (default on reset)
64 *
65 */
66 ret = tps65217_clear_bits(charger->tps, TPS65217_REG_CHGCONFIG1,
67 TPS65217_CHGCONFIG1_NTC_TYPE,
68 TPS65217_PROTECT_NONE);
69 if (ret) {
70 dev_err(charger->dev,
71 "failed to set 100k NTC setting: %d\n", ret);
72 return ret;
73 }
74
75 return 0;
76 }
77
tps65217_enable_charging(struct tps65217_charger * charger)78 static int tps65217_enable_charging(struct tps65217_charger *charger)
79 {
80 int ret;
81
82 /* charger already enabled */
83 if (charger->online)
84 return 0;
85
86 dev_dbg(charger->dev, "%s: enable charging\n", __func__);
87 ret = tps65217_set_bits(charger->tps, TPS65217_REG_CHGCONFIG1,
88 TPS65217_CHGCONFIG1_CHG_EN,
89 TPS65217_CHGCONFIG1_CHG_EN,
90 TPS65217_PROTECT_NONE);
91 if (ret) {
92 dev_err(charger->dev,
93 "%s: Error in writing CHG_EN in reg 0x%x: %d\n",
94 __func__, TPS65217_REG_CHGCONFIG1, ret);
95 return ret;
96 }
97
98 charger->online = 1;
99
100 return 0;
101 }
102
tps65217_charger_get_property(struct power_supply * psy,enum power_supply_property psp,union power_supply_propval * val)103 static int tps65217_charger_get_property(struct power_supply *psy,
104 enum power_supply_property psp,
105 union power_supply_propval *val)
106 {
107 struct tps65217_charger *charger = power_supply_get_drvdata(psy);
108
109 if (psp == POWER_SUPPLY_PROP_ONLINE) {
110 val->intval = charger->online;
111 return 0;
112 }
113 return -EINVAL;
114 }
115
tps65217_charger_irq(int irq,void * dev)116 static irqreturn_t tps65217_charger_irq(int irq, void *dev)
117 {
118 int ret, val;
119 struct tps65217_charger *charger = dev;
120
121 charger->prev_online = charger->online;
122
123 ret = tps65217_reg_read(charger->tps, TPS65217_REG_STATUS, &val);
124 if (ret < 0) {
125 dev_err(charger->dev, "%s: Error in reading reg 0x%x\n",
126 __func__, TPS65217_REG_STATUS);
127 return IRQ_HANDLED;
128 }
129
130 dev_dbg(charger->dev, "%s: 0x%x\n", __func__, val);
131
132 /* check for charger status bit */
133 if (val & CHARGER_STATUS_PRESENT) {
134 ret = tps65217_enable_charging(charger);
135 if (ret) {
136 dev_err(charger->dev,
137 "failed to enable charger: %d\n", ret);
138 return IRQ_HANDLED;
139 }
140 } else {
141 charger->online = 0;
142 }
143
144 if (charger->prev_online != charger->online)
145 power_supply_changed(charger->psy);
146
147 ret = tps65217_reg_read(charger->tps, TPS65217_REG_CHGCONFIG0, &val);
148 if (ret < 0) {
149 dev_err(charger->dev, "%s: Error in reading reg 0x%x\n",
150 __func__, TPS65217_REG_CHGCONFIG0);
151 return IRQ_HANDLED;
152 }
153
154 if (val & TPS65217_CHGCONFIG0_ACTIVE)
155 dev_dbg(charger->dev, "%s: charger is charging\n", __func__);
156 else
157 dev_dbg(charger->dev,
158 "%s: charger is NOT charging\n", __func__);
159
160 return IRQ_HANDLED;
161 }
162
tps65217_charger_poll_task(void * data)163 static int tps65217_charger_poll_task(void *data)
164 {
165 set_freezable();
166
167 while (!kthread_should_stop()) {
168 schedule_timeout_interruptible(POLL_INTERVAL);
169 try_to_freeze();
170 tps65217_charger_irq(-1, data);
171 }
172 return 0;
173 }
174
175 static const struct power_supply_desc tps65217_charger_desc = {
176 .name = "tps65217-charger",
177 .type = POWER_SUPPLY_TYPE_MAINS,
178 .get_property = tps65217_charger_get_property,
179 .properties = tps65217_charger_props,
180 .num_properties = ARRAY_SIZE(tps65217_charger_props),
181 };
182
tps65217_charger_probe(struct platform_device * pdev)183 static int tps65217_charger_probe(struct platform_device *pdev)
184 {
185 struct tps65217 *tps = dev_get_drvdata(pdev->dev.parent);
186 struct tps65217_charger *charger;
187 struct power_supply_config cfg = {};
188 struct task_struct *poll_task;
189 int irq[NUM_CHARGER_IRQS];
190 int ret;
191 int i;
192
193 charger = devm_kzalloc(&pdev->dev, sizeof(*charger), GFP_KERNEL);
194 if (!charger)
195 return -ENOMEM;
196
197 platform_set_drvdata(pdev, charger);
198 charger->tps = tps;
199 charger->dev = &pdev->dev;
200
201 cfg.of_node = pdev->dev.of_node;
202 cfg.drv_data = charger;
203
204 charger->psy = devm_power_supply_register(&pdev->dev,
205 &tps65217_charger_desc,
206 &cfg);
207 if (IS_ERR(charger->psy)) {
208 dev_err(&pdev->dev, "failed: power supply register\n");
209 return PTR_ERR(charger->psy);
210 }
211
212 irq[0] = platform_get_irq_byname(pdev, "USB");
213 irq[1] = platform_get_irq_byname(pdev, "AC");
214
215 ret = tps65217_config_charger(charger);
216 if (ret < 0) {
217 dev_err(charger->dev, "charger config failed, err %d\n", ret);
218 return ret;
219 }
220
221 /* Create a polling thread if an interrupt is invalid */
222 if (irq[0] < 0 || irq[1] < 0) {
223 poll_task = kthread_run(tps65217_charger_poll_task,
224 charger, "ktps65217charger");
225 if (IS_ERR(poll_task)) {
226 ret = PTR_ERR(poll_task);
227 dev_err(charger->dev,
228 "Unable to run kthread err %d\n", ret);
229 return ret;
230 }
231
232 charger->poll_task = poll_task;
233 return 0;
234 }
235
236 /* Create IRQ threads for charger interrupts */
237 for (i = 0; i < NUM_CHARGER_IRQS; i++) {
238 ret = devm_request_threaded_irq(&pdev->dev, irq[i], NULL,
239 tps65217_charger_irq,
240 IRQF_ONESHOT, "tps65217-charger",
241 charger);
242 if (ret) {
243 dev_err(charger->dev,
244 "Unable to register irq %d err %d\n", irq[i],
245 ret);
246 return ret;
247 }
248
249 /* Check current state */
250 tps65217_charger_irq(-1, charger);
251 }
252
253 return 0;
254 }
255
tps65217_charger_remove(struct platform_device * pdev)256 static int tps65217_charger_remove(struct platform_device *pdev)
257 {
258 struct tps65217_charger *charger = platform_get_drvdata(pdev);
259
260 if (charger->poll_task)
261 kthread_stop(charger->poll_task);
262
263 return 0;
264 }
265
266 static const struct of_device_id tps65217_charger_match_table[] = {
267 { .compatible = "ti,tps65217-charger", },
268 { /* sentinel */ }
269 };
270 MODULE_DEVICE_TABLE(of, tps65217_charger_match_table);
271
272 static struct platform_driver tps65217_charger_driver = {
273 .probe = tps65217_charger_probe,
274 .remove = tps65217_charger_remove,
275 .driver = {
276 .name = "tps65217-charger",
277 .of_match_table = of_match_ptr(tps65217_charger_match_table),
278 },
279
280 };
281 module_platform_driver(tps65217_charger_driver);
282
283 MODULE_LICENSE("GPL v2");
284 MODULE_AUTHOR("Enric Balletbo Serra <enric.balletbo@collabora.com>");
285 MODULE_DESCRIPTION("TPS65217 battery charger driver");
286