1 /*
2 * Battery charger driver for TI's tps65217
3 *
4 * Copyright (c) 2015, Collabora Ltd.
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
19 /*
20 * Battery charger driver for TI's tps65217
21 */
22 #include <linux/kernel.h>
23 #include <linux/kthread.h>
24 #include <linux/device.h>
25 #include <linux/module.h>
26 #include <linux/platform_device.h>
27 #include <linux/init.h>
28 #include <linux/interrupt.h>
29 #include <linux/slab.h>
30 #include <linux/err.h>
31 #include <linux/of.h>
32 #include <linux/of_device.h>
33 #include <linux/power_supply.h>
34
35 #include <linux/mfd/core.h>
36 #include <linux/mfd/tps65217.h>
37
38 #define POLL_INTERVAL (HZ * 2)
39
40 struct tps65217_charger {
41 struct tps65217 *tps;
42 struct device *dev;
43 struct power_supply *ac;
44
45 int ac_online;
46 int prev_ac_online;
47
48 struct task_struct *poll_task;
49 };
50
51 static enum power_supply_property tps65217_ac_props[] = {
52 POWER_SUPPLY_PROP_ONLINE,
53 };
54
tps65217_config_charger(struct tps65217_charger * charger)55 static int tps65217_config_charger(struct tps65217_charger *charger)
56 {
57 int ret;
58
59 dev_dbg(charger->dev, "%s\n", __func__);
60
61 /*
62 * tps65217 rev. G, p. 31 (see p. 32 for NTC schematic)
63 *
64 * The device can be configured to support a 100k NTC (B = 3960) by
65 * setting the the NTC_TYPE bit in register CHGCONFIG1 to 1. However it
66 * is not recommended to do so. In sleep mode, the charger continues
67 * charging the battery, but all register values are reset to default
68 * values. Therefore, the charger would get the wrong temperature
69 * information. If 100k NTC setting is required, please contact the
70 * factory.
71 *
72 * ATTENTION, conflicting information, from p. 46
73 *
74 * NTC TYPE (for battery temperature measurement)
75 * 0 – 100k (curve 1, B = 3960)
76 * 1 – 10k (curve 2, B = 3480) (default on reset)
77 *
78 */
79 ret = tps65217_clear_bits(charger->tps, TPS65217_REG_CHGCONFIG1,
80 TPS65217_CHGCONFIG1_NTC_TYPE,
81 TPS65217_PROTECT_NONE);
82 if (ret) {
83 dev_err(charger->dev,
84 "failed to set 100k NTC setting: %d\n", ret);
85 return ret;
86 }
87
88 return 0;
89 }
90
tps65217_enable_charging(struct tps65217_charger * charger)91 static int tps65217_enable_charging(struct tps65217_charger *charger)
92 {
93 int ret;
94
95 /* charger already enabled */
96 if (charger->ac_online)
97 return 0;
98
99 dev_dbg(charger->dev, "%s: enable charging\n", __func__);
100 ret = tps65217_set_bits(charger->tps, TPS65217_REG_CHGCONFIG1,
101 TPS65217_CHGCONFIG1_CHG_EN,
102 TPS65217_CHGCONFIG1_CHG_EN,
103 TPS65217_PROTECT_NONE);
104 if (ret) {
105 dev_err(charger->dev,
106 "%s: Error in writing CHG_EN in reg 0x%x: %d\n",
107 __func__, TPS65217_REG_CHGCONFIG1, ret);
108 return ret;
109 }
110
111 charger->ac_online = 1;
112
113 return 0;
114 }
115
tps65217_ac_get_property(struct power_supply * psy,enum power_supply_property psp,union power_supply_propval * val)116 static int tps65217_ac_get_property(struct power_supply *psy,
117 enum power_supply_property psp,
118 union power_supply_propval *val)
119 {
120 struct tps65217_charger *charger = power_supply_get_drvdata(psy);
121
122 if (psp == POWER_SUPPLY_PROP_ONLINE) {
123 val->intval = charger->ac_online;
124 return 0;
125 }
126 return -EINVAL;
127 }
128
tps65217_charger_irq(int irq,void * dev)129 static irqreturn_t tps65217_charger_irq(int irq, void *dev)
130 {
131 int ret, val;
132 struct tps65217_charger *charger = dev;
133
134 charger->prev_ac_online = charger->ac_online;
135
136 ret = tps65217_reg_read(charger->tps, TPS65217_REG_STATUS, &val);
137 if (ret < 0) {
138 dev_err(charger->dev, "%s: Error in reading reg 0x%x\n",
139 __func__, TPS65217_REG_STATUS);
140 return IRQ_HANDLED;
141 }
142
143 dev_dbg(charger->dev, "%s: 0x%x\n", __func__, val);
144
145 /* check for AC status bit */
146 if (val & TPS65217_STATUS_ACPWR) {
147 ret = tps65217_enable_charging(charger);
148 if (ret) {
149 dev_err(charger->dev,
150 "failed to enable charger: %d\n", ret);
151 return IRQ_HANDLED;
152 }
153 } else {
154 charger->ac_online = 0;
155 }
156
157 if (charger->prev_ac_online != charger->ac_online)
158 power_supply_changed(charger->ac);
159
160 ret = tps65217_reg_read(charger->tps, TPS65217_REG_CHGCONFIG0, &val);
161 if (ret < 0) {
162 dev_err(charger->dev, "%s: Error in reading reg 0x%x\n",
163 __func__, TPS65217_REG_CHGCONFIG0);
164 return IRQ_HANDLED;
165 }
166
167 if (val & TPS65217_CHGCONFIG0_ACTIVE)
168 dev_dbg(charger->dev, "%s: charger is charging\n", __func__);
169 else
170 dev_dbg(charger->dev,
171 "%s: charger is NOT charging\n", __func__);
172
173 return IRQ_HANDLED;
174 }
175
tps65217_charger_poll_task(void * data)176 static int tps65217_charger_poll_task(void *data)
177 {
178 set_freezable();
179
180 while (!kthread_should_stop()) {
181 schedule_timeout_interruptible(POLL_INTERVAL);
182 try_to_freeze();
183 tps65217_charger_irq(-1, data);
184 }
185 return 0;
186 }
187
188 static const struct power_supply_desc tps65217_charger_desc = {
189 .name = "tps65217-ac",
190 .type = POWER_SUPPLY_TYPE_MAINS,
191 .get_property = tps65217_ac_get_property,
192 .properties = tps65217_ac_props,
193 .num_properties = ARRAY_SIZE(tps65217_ac_props),
194 };
195
tps65217_charger_probe(struct platform_device * pdev)196 static int tps65217_charger_probe(struct platform_device *pdev)
197 {
198 struct tps65217 *tps = dev_get_drvdata(pdev->dev.parent);
199 struct tps65217_charger *charger;
200 int ret;
201
202 dev_dbg(&pdev->dev, "%s\n", __func__);
203
204 charger = devm_kzalloc(&pdev->dev, sizeof(*charger), GFP_KERNEL);
205 if (!charger)
206 return -ENOMEM;
207
208 charger->tps = tps;
209 charger->dev = &pdev->dev;
210
211 charger->ac = devm_power_supply_register(&pdev->dev,
212 &tps65217_charger_desc,
213 NULL);
214 if (IS_ERR(charger->ac)) {
215 dev_err(&pdev->dev, "failed: power supply register\n");
216 return PTR_ERR(charger->ac);
217 }
218
219 ret = tps65217_config_charger(charger);
220 if (ret < 0) {
221 dev_err(charger->dev, "charger config failed, err %d\n", ret);
222 return ret;
223 }
224
225 charger->poll_task = kthread_run(tps65217_charger_poll_task,
226 charger, "ktps65217charger");
227 if (IS_ERR(charger->poll_task)) {
228 ret = PTR_ERR(charger->poll_task);
229 dev_err(charger->dev, "Unable to run kthread err %d\n", ret);
230 return ret;
231 }
232
233 return 0;
234 }
235
tps65217_charger_remove(struct platform_device * pdev)236 static int tps65217_charger_remove(struct platform_device *pdev)
237 {
238 struct tps65217_charger *charger = platform_get_drvdata(pdev);
239
240 kthread_stop(charger->poll_task);
241
242 return 0;
243 }
244
245 static const struct of_device_id tps65217_charger_match_table[] = {
246 { .compatible = "ti,tps65217-charger", },
247 { /* sentinel */ }
248 };
249 MODULE_DEVICE_TABLE(of, tps65217_charger_match_table);
250
251 static struct platform_driver tps65217_charger_driver = {
252 .probe = tps65217_charger_probe,
253 .remove = tps65217_charger_remove,
254 .driver = {
255 .name = "tps65217-charger",
256 .of_match_table = of_match_ptr(tps65217_charger_match_table),
257 },
258
259 };
260 module_platform_driver(tps65217_charger_driver);
261
262 MODULE_LICENSE("GPL v2");
263 MODULE_AUTHOR("Enric Balletbo Serra <enric.balletbo@collabora.com>");
264 MODULE_DESCRIPTION("TPS65217 battery charger driver");
265