1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Charging control driver for the Wilco EC
4 *
5 * Copyright 2019 Google LLC
6 *
7 * See Documentation/ABI/testing/sysfs-class-power and
8 * Documentation/ABI/testing/sysfs-class-power-wilco for userspace interface
9 * and other info.
10 */
11
12 #include <linux/module.h>
13 #include <linux/platform_device.h>
14 #include <linux/platform_data/wilco-ec.h>
15 #include <linux/power_supply.h>
16
17 #define DRV_NAME "wilco-charger"
18
19 /* Property IDs and related EC constants */
20 #define PID_CHARGE_MODE 0x0710
21 #define PID_CHARGE_LOWER_LIMIT 0x0711
22 #define PID_CHARGE_UPPER_LIMIT 0x0712
23
24 enum charge_mode {
25 CHARGE_MODE_STD = 1, /* Used for Standard */
26 CHARGE_MODE_EXP = 2, /* Express Charge, used for Fast */
27 CHARGE_MODE_AC = 3, /* Mostly AC use, used for Trickle */
28 CHARGE_MODE_AUTO = 4, /* Used for Adaptive */
29 CHARGE_MODE_CUSTOM = 5, /* Used for Custom */
30 CHARGE_MODE_LONGLIFE = 6, /* Used for Long Life */
31 };
32
33 #define CHARGE_LOWER_LIMIT_MIN 50
34 #define CHARGE_LOWER_LIMIT_MAX 95
35 #define CHARGE_UPPER_LIMIT_MIN 55
36 #define CHARGE_UPPER_LIMIT_MAX 100
37
38 /* Convert from POWER_SUPPLY_PROP_CHARGE_TYPE value to the EC's charge mode */
psp_val_to_charge_mode(int psp_val)39 static int psp_val_to_charge_mode(int psp_val)
40 {
41 switch (psp_val) {
42 case POWER_SUPPLY_CHARGE_TYPE_TRICKLE:
43 return CHARGE_MODE_AC;
44 case POWER_SUPPLY_CHARGE_TYPE_FAST:
45 return CHARGE_MODE_EXP;
46 case POWER_SUPPLY_CHARGE_TYPE_STANDARD:
47 return CHARGE_MODE_STD;
48 case POWER_SUPPLY_CHARGE_TYPE_ADAPTIVE:
49 return CHARGE_MODE_AUTO;
50 case POWER_SUPPLY_CHARGE_TYPE_CUSTOM:
51 return CHARGE_MODE_CUSTOM;
52 case POWER_SUPPLY_CHARGE_TYPE_LONGLIFE:
53 return CHARGE_MODE_LONGLIFE;
54 default:
55 return -EINVAL;
56 }
57 }
58
59 /* Convert from EC's charge mode to POWER_SUPPLY_PROP_CHARGE_TYPE value */
charge_mode_to_psp_val(enum charge_mode mode)60 static int charge_mode_to_psp_val(enum charge_mode mode)
61 {
62 switch (mode) {
63 case CHARGE_MODE_AC:
64 return POWER_SUPPLY_CHARGE_TYPE_TRICKLE;
65 case CHARGE_MODE_EXP:
66 return POWER_SUPPLY_CHARGE_TYPE_FAST;
67 case CHARGE_MODE_STD:
68 return POWER_SUPPLY_CHARGE_TYPE_STANDARD;
69 case CHARGE_MODE_AUTO:
70 return POWER_SUPPLY_CHARGE_TYPE_ADAPTIVE;
71 case CHARGE_MODE_CUSTOM:
72 return POWER_SUPPLY_CHARGE_TYPE_CUSTOM;
73 case CHARGE_MODE_LONGLIFE:
74 return POWER_SUPPLY_CHARGE_TYPE_LONGLIFE;
75 default:
76 return -EINVAL;
77 }
78 }
79
80 static enum power_supply_property wilco_charge_props[] = {
81 POWER_SUPPLY_PROP_CHARGE_TYPE,
82 POWER_SUPPLY_PROP_CHARGE_CONTROL_START_THRESHOLD,
83 POWER_SUPPLY_PROP_CHARGE_CONTROL_END_THRESHOLD,
84 };
85
wilco_charge_get_property(struct power_supply * psy,enum power_supply_property psp,union power_supply_propval * val)86 static int wilco_charge_get_property(struct power_supply *psy,
87 enum power_supply_property psp,
88 union power_supply_propval *val)
89 {
90 struct wilco_ec_device *ec = power_supply_get_drvdata(psy);
91 u32 property_id;
92 int ret;
93 u8 raw;
94
95 switch (psp) {
96 case POWER_SUPPLY_PROP_CHARGE_TYPE:
97 property_id = PID_CHARGE_MODE;
98 break;
99 case POWER_SUPPLY_PROP_CHARGE_CONTROL_START_THRESHOLD:
100 property_id = PID_CHARGE_LOWER_LIMIT;
101 break;
102 case POWER_SUPPLY_PROP_CHARGE_CONTROL_END_THRESHOLD:
103 property_id = PID_CHARGE_UPPER_LIMIT;
104 break;
105 default:
106 return -EINVAL;
107 }
108
109 ret = wilco_ec_get_byte_property(ec, property_id, &raw);
110 if (ret < 0)
111 return ret;
112 if (property_id == PID_CHARGE_MODE) {
113 ret = charge_mode_to_psp_val(raw);
114 if (ret < 0)
115 return -EBADMSG;
116 raw = ret;
117 }
118 val->intval = raw;
119
120 return 0;
121 }
122
wilco_charge_set_property(struct power_supply * psy,enum power_supply_property psp,const union power_supply_propval * val)123 static int wilco_charge_set_property(struct power_supply *psy,
124 enum power_supply_property psp,
125 const union power_supply_propval *val)
126 {
127 struct wilco_ec_device *ec = power_supply_get_drvdata(psy);
128 int mode;
129
130 switch (psp) {
131 case POWER_SUPPLY_PROP_CHARGE_TYPE:
132 mode = psp_val_to_charge_mode(val->intval);
133 if (mode < 0)
134 return -EINVAL;
135 return wilco_ec_set_byte_property(ec, PID_CHARGE_MODE, mode);
136 case POWER_SUPPLY_PROP_CHARGE_CONTROL_START_THRESHOLD:
137 if (val->intval < CHARGE_LOWER_LIMIT_MIN ||
138 val->intval > CHARGE_LOWER_LIMIT_MAX)
139 return -EINVAL;
140 return wilco_ec_set_byte_property(ec, PID_CHARGE_LOWER_LIMIT,
141 val->intval);
142 case POWER_SUPPLY_PROP_CHARGE_CONTROL_END_THRESHOLD:
143 if (val->intval < CHARGE_UPPER_LIMIT_MIN ||
144 val->intval > CHARGE_UPPER_LIMIT_MAX)
145 return -EINVAL;
146 return wilco_ec_set_byte_property(ec, PID_CHARGE_UPPER_LIMIT,
147 val->intval);
148 default:
149 return -EINVAL;
150 }
151 }
152
wilco_charge_property_is_writeable(struct power_supply * psy,enum power_supply_property psp)153 static int wilco_charge_property_is_writeable(struct power_supply *psy,
154 enum power_supply_property psp)
155 {
156 return 1;
157 }
158
159 static const struct power_supply_desc wilco_ps_desc = {
160 .properties = wilco_charge_props,
161 .num_properties = ARRAY_SIZE(wilco_charge_props),
162 .get_property = wilco_charge_get_property,
163 .set_property = wilco_charge_set_property,
164 .property_is_writeable = wilco_charge_property_is_writeable,
165 .name = DRV_NAME,
166 .type = POWER_SUPPLY_TYPE_MAINS,
167 };
168
wilco_charge_probe(struct platform_device * pdev)169 static int wilco_charge_probe(struct platform_device *pdev)
170 {
171 struct wilco_ec_device *ec = dev_get_drvdata(pdev->dev.parent);
172 struct power_supply_config psy_cfg = {};
173 struct power_supply *psy;
174
175 psy_cfg.drv_data = ec;
176 psy = devm_power_supply_register(&pdev->dev, &wilco_ps_desc, &psy_cfg);
177
178 return PTR_ERR_OR_ZERO(psy);
179 }
180
181 static struct platform_driver wilco_charge_driver = {
182 .probe = wilco_charge_probe,
183 .driver = {
184 .name = DRV_NAME,
185 }
186 };
187 module_platform_driver(wilco_charge_driver);
188
189 MODULE_ALIAS("platform:" DRV_NAME);
190 MODULE_AUTHOR("Nick Crews <ncrews@chromium.org>");
191 MODULE_LICENSE("GPL v2");
192 MODULE_DESCRIPTION("Wilco EC charge control driver");
193