1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * Copyright (c) 2016, Prodys S.L. |
4 | * |
5 | * This adds support for sbs-charger compilant chips as defined here: |
6 | * http://sbs-forum.org/specs/sbc110.pdf |
7 | * |
8 | * Implemetation based on sbs-battery.c |
9 | */ |
10 | |
11 | #include <linux/init.h> |
12 | #include <linux/module.h> |
13 | #include <linux/kernel.h> |
14 | #include <linux/err.h> |
15 | #include <linux/power_supply.h> |
16 | #include <linux/i2c.h> |
17 | #include <linux/slab.h> |
18 | #include <linux/interrupt.h> |
19 | #include <linux/regmap.h> |
20 | #include <linux/bitops.h> |
21 | #include <linux/devm-helpers.h> |
22 | |
23 | #define SBS_CHARGER_REG_SPEC_INFO 0x11 |
24 | #define SBS_CHARGER_REG_STATUS 0x13 |
25 | #define SBS_CHARGER_REG_ALARM_WARNING 0x16 |
26 | |
27 | #define SBS_CHARGER_STATUS_CHARGE_INHIBITED BIT(0) |
28 | #define SBS_CHARGER_STATUS_RES_COLD BIT(9) |
29 | #define SBS_CHARGER_STATUS_RES_HOT BIT(10) |
30 | #define SBS_CHARGER_STATUS_BATTERY_PRESENT BIT(14) |
31 | #define SBS_CHARGER_STATUS_AC_PRESENT BIT(15) |
32 | |
33 | #define SBS_CHARGER_POLL_TIME 500 |
34 | |
35 | struct sbs_info { |
36 | struct i2c_client *client; |
37 | struct power_supply *power_supply; |
38 | struct regmap *regmap; |
39 | struct delayed_work work; |
40 | unsigned int last_state; |
41 | }; |
42 | |
43 | static int sbs_get_property(struct power_supply *psy, |
44 | enum power_supply_property psp, |
45 | union power_supply_propval *val) |
46 | { |
47 | struct sbs_info *chip = power_supply_get_drvdata(psy); |
48 | unsigned int reg; |
49 | |
50 | reg = chip->last_state; |
51 | |
52 | switch (psp) { |
53 | case POWER_SUPPLY_PROP_PRESENT: |
54 | val->intval = !!(reg & SBS_CHARGER_STATUS_BATTERY_PRESENT); |
55 | break; |
56 | |
57 | case POWER_SUPPLY_PROP_ONLINE: |
58 | val->intval = !!(reg & SBS_CHARGER_STATUS_AC_PRESENT); |
59 | break; |
60 | |
61 | case POWER_SUPPLY_PROP_STATUS: |
62 | val->intval = POWER_SUPPLY_STATUS_UNKNOWN; |
63 | |
64 | if (!(reg & SBS_CHARGER_STATUS_BATTERY_PRESENT)) |
65 | val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING; |
66 | else if (reg & SBS_CHARGER_STATUS_AC_PRESENT && |
67 | !(reg & SBS_CHARGER_STATUS_CHARGE_INHIBITED)) |
68 | val->intval = POWER_SUPPLY_STATUS_CHARGING; |
69 | else |
70 | val->intval = POWER_SUPPLY_STATUS_DISCHARGING; |
71 | |
72 | break; |
73 | |
74 | case POWER_SUPPLY_PROP_HEALTH: |
75 | if (reg & SBS_CHARGER_STATUS_RES_COLD) |
76 | val->intval = POWER_SUPPLY_HEALTH_COLD; |
77 | if (reg & SBS_CHARGER_STATUS_RES_HOT) |
78 | val->intval = POWER_SUPPLY_HEALTH_OVERHEAT; |
79 | else |
80 | val->intval = POWER_SUPPLY_HEALTH_GOOD; |
81 | |
82 | break; |
83 | |
84 | default: |
85 | return -EINVAL; |
86 | } |
87 | |
88 | return 0; |
89 | } |
90 | |
91 | static int sbs_check_state(struct sbs_info *chip) |
92 | { |
93 | unsigned int reg; |
94 | int ret; |
95 | |
96 | ret = regmap_read(map: chip->regmap, SBS_CHARGER_REG_STATUS, val: ®); |
97 | if (!ret && reg != chip->last_state) { |
98 | chip->last_state = reg; |
99 | power_supply_changed(psy: chip->power_supply); |
100 | return 1; |
101 | } |
102 | |
103 | return 0; |
104 | } |
105 | |
106 | static void sbs_delayed_work(struct work_struct *work) |
107 | { |
108 | struct sbs_info *chip = container_of(work, struct sbs_info, work.work); |
109 | |
110 | sbs_check_state(chip); |
111 | |
112 | schedule_delayed_work(dwork: &chip->work, |
113 | delay: msecs_to_jiffies(SBS_CHARGER_POLL_TIME)); |
114 | } |
115 | |
116 | static irqreturn_t sbs_irq_thread(int irq, void *data) |
117 | { |
118 | struct sbs_info *chip = data; |
119 | int ret; |
120 | |
121 | ret = sbs_check_state(chip); |
122 | |
123 | return ret ? IRQ_HANDLED : IRQ_NONE; |
124 | } |
125 | |
126 | static enum power_supply_property sbs_properties[] = { |
127 | POWER_SUPPLY_PROP_STATUS, |
128 | POWER_SUPPLY_PROP_PRESENT, |
129 | POWER_SUPPLY_PROP_ONLINE, |
130 | POWER_SUPPLY_PROP_HEALTH, |
131 | }; |
132 | |
133 | static bool sbs_readable_reg(struct device *dev, unsigned int reg) |
134 | { |
135 | return reg >= SBS_CHARGER_REG_SPEC_INFO; |
136 | } |
137 | |
138 | static bool sbs_volatile_reg(struct device *dev, unsigned int reg) |
139 | { |
140 | switch (reg) { |
141 | case SBS_CHARGER_REG_STATUS: |
142 | return true; |
143 | } |
144 | |
145 | return false; |
146 | } |
147 | |
148 | static const struct regmap_config sbs_regmap = { |
149 | .reg_bits = 8, |
150 | .val_bits = 16, |
151 | .max_register = SBS_CHARGER_REG_ALARM_WARNING, |
152 | .readable_reg = sbs_readable_reg, |
153 | .volatile_reg = sbs_volatile_reg, |
154 | .val_format_endian = REGMAP_ENDIAN_LITTLE, /* since based on SMBus */ |
155 | }; |
156 | |
157 | static const struct power_supply_desc sbs_desc = { |
158 | .name = "sbs-charger" , |
159 | .type = POWER_SUPPLY_TYPE_MAINS, |
160 | .properties = sbs_properties, |
161 | .num_properties = ARRAY_SIZE(sbs_properties), |
162 | .get_property = sbs_get_property, |
163 | }; |
164 | |
165 | static int sbs_probe(struct i2c_client *client) |
166 | { |
167 | struct power_supply_config psy_cfg = {}; |
168 | struct sbs_info *chip; |
169 | int ret, val; |
170 | |
171 | chip = devm_kzalloc(dev: &client->dev, size: sizeof(struct sbs_info), GFP_KERNEL); |
172 | if (!chip) |
173 | return -ENOMEM; |
174 | |
175 | chip->client = client; |
176 | psy_cfg.of_node = client->dev.of_node; |
177 | psy_cfg.drv_data = chip; |
178 | |
179 | i2c_set_clientdata(client, data: chip); |
180 | |
181 | chip->regmap = devm_regmap_init_i2c(client, &sbs_regmap); |
182 | if (IS_ERR(ptr: chip->regmap)) |
183 | return PTR_ERR(ptr: chip->regmap); |
184 | |
185 | /* |
186 | * Before we register, we need to make sure we can actually talk |
187 | * to the battery. |
188 | */ |
189 | ret = regmap_read(map: chip->regmap, SBS_CHARGER_REG_STATUS, val: &val); |
190 | if (ret) |
191 | return dev_err_probe(dev: &client->dev, err: ret, fmt: "Failed to get device status\n" ); |
192 | chip->last_state = val; |
193 | |
194 | chip->power_supply = devm_power_supply_register(parent: &client->dev, desc: &sbs_desc, cfg: &psy_cfg); |
195 | if (IS_ERR(ptr: chip->power_supply)) |
196 | return dev_err_probe(dev: &client->dev, err: PTR_ERR(ptr: chip->power_supply), |
197 | fmt: "Failed to register power supply\n" ); |
198 | |
199 | /* |
200 | * The sbs-charger spec doesn't impose the use of an interrupt. So in |
201 | * the case it wasn't provided we use polling in order get the charger's |
202 | * status. |
203 | */ |
204 | if (client->irq) { |
205 | ret = devm_request_threaded_irq(dev: &client->dev, irq: client->irq, |
206 | NULL, thread_fn: sbs_irq_thread, |
207 | IRQF_TRIGGER_FALLING | IRQF_ONESHOT, |
208 | devname: dev_name(dev: &client->dev), dev_id: chip); |
209 | if (ret) |
210 | return dev_err_probe(dev: &client->dev, err: ret, fmt: "Failed to request irq\n" ); |
211 | } else { |
212 | ret = devm_delayed_work_autocancel(dev: &client->dev, w: &chip->work, |
213 | worker: sbs_delayed_work); |
214 | if (ret) |
215 | return dev_err_probe(dev: &client->dev, err: ret, |
216 | fmt: "Failed to init work for polling\n" ); |
217 | |
218 | schedule_delayed_work(dwork: &chip->work, |
219 | delay: msecs_to_jiffies(SBS_CHARGER_POLL_TIME)); |
220 | } |
221 | |
222 | dev_info(&client->dev, |
223 | "%s: smart charger device registered\n" , client->name); |
224 | |
225 | return 0; |
226 | } |
227 | |
228 | #ifdef CONFIG_OF |
229 | static const struct of_device_id sbs_dt_ids[] = { |
230 | { .compatible = "sbs,sbs-charger" }, |
231 | { }, |
232 | }; |
233 | MODULE_DEVICE_TABLE(of, sbs_dt_ids); |
234 | #endif |
235 | |
236 | static const struct i2c_device_id sbs_id[] = { |
237 | { "sbs-charger" , 0 }, |
238 | { } |
239 | }; |
240 | MODULE_DEVICE_TABLE(i2c, sbs_id); |
241 | |
242 | static struct i2c_driver sbs_driver = { |
243 | .probe = sbs_probe, |
244 | .id_table = sbs_id, |
245 | .driver = { |
246 | .name = "sbs-charger" , |
247 | .of_match_table = of_match_ptr(sbs_dt_ids), |
248 | }, |
249 | }; |
250 | module_i2c_driver(sbs_driver); |
251 | |
252 | MODULE_AUTHOR("Nicolas Saenz Julienne <nicolassaenzj@gmail.com>" ); |
253 | MODULE_DESCRIPTION("SBS smart charger driver" ); |
254 | MODULE_LICENSE("GPL v2" ); |
255 | |