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1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Fast-charge control for Apple "MFi" devices
4 *
5 * Copyright (C) 2019 Bastien Nocera <hadess@hadess.net>
6 */
7
8/* Standard include files */
9#include <linux/module.h>
10#include <linux/power_supply.h>
11#include <linux/slab.h>
12#include <linux/usb.h>
13
14MODULE_AUTHOR("Bastien Nocera <hadess@hadess.net>");
15MODULE_DESCRIPTION("Fast-charge control for Apple \"MFi\" devices");
16MODULE_LICENSE("GPL");
17
18#define TRICKLE_CURRENT_MA 0
19#define FAST_CURRENT_MA 2500
20
21#define APPLE_VENDOR_ID 0x05ac /* Apple */
22
23/* The product ID is defined as starting with 0x12nn, as per the
24 * "Choosing an Apple Device USB Configuration" section in
25 * release R9 (2012) of the "MFi Accessory Hardware Specification"
26 *
27 * To distinguish an Apple device, a USB host can check the device
28 * descriptor of attached USB devices for the following fields:
29 * ■ Vendor ID: 0x05AC
30 * ■ Product ID: 0x12nn
31 *
32 * Those checks will be done in .match() and .probe().
33 */
34
35static const struct usb_device_id mfi_fc_id_table[] = {
36 { .idVendor = APPLE_VENDOR_ID,
37 .match_flags = USB_DEVICE_ID_MATCH_VENDOR },
38 {},
39};
40
41MODULE_DEVICE_TABLE(usb, mfi_fc_id_table);
42
43/* Driver-local specific stuff */
44struct mfi_device {
45 struct usb_device *udev;
46 struct power_supply *battery;
47 int charge_type;
48};
49
50static int apple_mfi_fc_set_charge_type(struct mfi_device *mfi,
51 const union power_supply_propval *val)
52{
53 int current_ma;
54 int retval;
55 __u8 request_type;
56
57 if (mfi->charge_type == val->intval) {
58 dev_dbg(&mfi->udev->dev, "charge type %d already set\n",
59 mfi->charge_type);
60 return 0;
61 }
62
63 switch (val->intval) {
64 case POWER_SUPPLY_CHARGE_TYPE_TRICKLE:
65 current_ma = TRICKLE_CURRENT_MA;
66 break;
67 case POWER_SUPPLY_CHARGE_TYPE_FAST:
68 current_ma = FAST_CURRENT_MA;
69 break;
70 default:
71 return -EINVAL;
72 }
73
74 request_type = USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE;
75 retval = usb_control_msg(mfi->udev, usb_sndctrlpipe(mfi->udev, 0),
76 0x40, /* Vendor‐defined power request */
77 request_type,
78 current_ma, /* wValue, current offset */
79 current_ma, /* wIndex, current offset */
80 NULL, 0, USB_CTRL_GET_TIMEOUT);
81 if (retval) {
82 dev_dbg(&mfi->udev->dev, "retval = %d\n", retval);
83 return retval;
84 }
85
86 mfi->charge_type = val->intval;
87
88 return 0;
89}
90
91static int apple_mfi_fc_get_property(struct power_supply *psy,
92 enum power_supply_property psp,
93 union power_supply_propval *val)
94{
95 struct mfi_device *mfi = power_supply_get_drvdata(psy);
96
97 dev_dbg(&mfi->udev->dev, "prop: %d\n", psp);
98
99 switch (psp) {
100 case POWER_SUPPLY_PROP_CHARGE_TYPE:
101 val->intval = mfi->charge_type;
102 break;
103 case POWER_SUPPLY_PROP_SCOPE:
104 val->intval = POWER_SUPPLY_SCOPE_DEVICE;
105 break;
106 default:
107 return -ENODATA;
108 }
109
110 return 0;
111}
112
113static int apple_mfi_fc_set_property(struct power_supply *psy,
114 enum power_supply_property psp,
115 const union power_supply_propval *val)
116{
117 struct mfi_device *mfi = power_supply_get_drvdata(psy);
118 int ret;
119
120 dev_dbg(&mfi->udev->dev, "prop: %d\n", psp);
121
122 ret = pm_runtime_get_sync(&mfi->udev->dev);
123 if (ret < 0)
124 return ret;
125
126 switch (psp) {
127 case POWER_SUPPLY_PROP_CHARGE_TYPE:
128 ret = apple_mfi_fc_set_charge_type(mfi, val);
129 break;
130 default:
131 ret = -EINVAL;
132 }
133
134 pm_runtime_mark_last_busy(&mfi->udev->dev);
135 pm_runtime_put_autosuspend(&mfi->udev->dev);
136
137 return ret;
138}
139
140static int apple_mfi_fc_property_is_writeable(struct power_supply *psy,
141 enum power_supply_property psp)
142{
143 switch (psp) {
144 case POWER_SUPPLY_PROP_CHARGE_TYPE:
145 return 1;
146 default:
147 return 0;
148 }
149}
150
151static enum power_supply_property apple_mfi_fc_properties[] = {
152 POWER_SUPPLY_PROP_CHARGE_TYPE,
153 POWER_SUPPLY_PROP_SCOPE
154};
155
156static const struct power_supply_desc apple_mfi_fc_desc = {
157 .name = "apple_mfi_fastcharge",
158 .type = POWER_SUPPLY_TYPE_BATTERY,
159 .properties = apple_mfi_fc_properties,
160 .num_properties = ARRAY_SIZE(apple_mfi_fc_properties),
161 .get_property = apple_mfi_fc_get_property,
162 .set_property = apple_mfi_fc_set_property,
163 .property_is_writeable = apple_mfi_fc_property_is_writeable
164};
165
166static int mfi_fc_probe(struct usb_device *udev)
167{
168 struct power_supply_config battery_cfg = {};
169 struct mfi_device *mfi = NULL;
170 int err, idProduct;
171
172 idProduct = le16_to_cpu(udev->descriptor.idProduct);
173 /* See comment above mfi_fc_id_table[] */
174 if (idProduct < 0x1200 || idProduct > 0x12ff) {
175 return -ENODEV;
176 }
177
178 mfi = kzalloc(sizeof(struct mfi_device), GFP_KERNEL);
179 if (!mfi) {
180 err = -ENOMEM;
181 goto error;
182 }
183
184 battery_cfg.drv_data = mfi;
185
186 mfi->charge_type = POWER_SUPPLY_CHARGE_TYPE_TRICKLE;
187 mfi->battery = power_supply_register(&udev->dev,
188 &apple_mfi_fc_desc,
189 &battery_cfg);
190 if (IS_ERR(mfi->battery)) {
191 dev_err(&udev->dev, "Can't register battery\n");
192 err = PTR_ERR(mfi->battery);
193 goto error;
194 }
195
196 mfi->udev = usb_get_dev(udev);
197 dev_set_drvdata(&udev->dev, mfi);
198
199 return 0;
200
201error:
202 kfree(mfi);
203 return err;
204}
205
206static void mfi_fc_disconnect(struct usb_device *udev)
207{
208 struct mfi_device *mfi;
209
210 mfi = dev_get_drvdata(&udev->dev);
211 if (mfi->battery)
212 power_supply_unregister(mfi->battery);
213 dev_set_drvdata(&udev->dev, NULL);
214 usb_put_dev(mfi->udev);
215 kfree(mfi);
216}
217
218static struct usb_device_driver mfi_fc_driver = {
219 .name = "apple-mfi-fastcharge",
220 .probe = mfi_fc_probe,
221 .disconnect = mfi_fc_disconnect,
222 .id_table = mfi_fc_id_table,
223 .generic_subclass = 1,
224};
225
226static int __init mfi_fc_driver_init(void)
227{
228 return usb_register_device_driver(&mfi_fc_driver, THIS_MODULE);
229}
230
231static void __exit mfi_fc_driver_exit(void)
232{
233 usb_deregister_device_driver(&mfi_fc_driver);
234}
235
236module_init(mfi_fc_driver_init);
237module_exit(mfi_fc_driver_exit);
1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Fast-charge control for Apple "MFi" devices
4 *
5 * Copyright (C) 2019 Bastien Nocera <hadess@hadess.net>
6 */
7
8/* Standard include files */
9#include <linux/module.h>
10#include <linux/power_supply.h>
11#include <linux/slab.h>
12#include <linux/usb.h>
13
14MODULE_AUTHOR("Bastien Nocera <hadess@hadess.net>");
15MODULE_DESCRIPTION("Fast-charge control for Apple \"MFi\" devices");
16MODULE_LICENSE("GPL");
17
18#define TRICKLE_CURRENT_MA 0
19#define FAST_CURRENT_MA 2500
20
21#define APPLE_VENDOR_ID 0x05ac /* Apple */
22
23/* The product ID is defined as starting with 0x12nn, as per the
24 * "Choosing an Apple Device USB Configuration" section in
25 * release R9 (2012) of the "MFi Accessory Hardware Specification"
26 *
27 * To distinguish an Apple device, a USB host can check the device
28 * descriptor of attached USB devices for the following fields:
29 * ■ Vendor ID: 0x05AC
30 * ■ Product ID: 0x12nn
31 *
32 * Those checks will be done in .match() and .probe().
33 */
34
35static const struct usb_device_id mfi_fc_id_table[] = {
36 { .idVendor = APPLE_VENDOR_ID,
37 .match_flags = USB_DEVICE_ID_MATCH_VENDOR },
38 {},
39};
40
41MODULE_DEVICE_TABLE(usb, mfi_fc_id_table);
42
43/* Driver-local specific stuff */
44struct mfi_device {
45 struct usb_device *udev;
46 struct power_supply *battery;
47 int charge_type;
48};
49
50static int apple_mfi_fc_set_charge_type(struct mfi_device *mfi,
51 const union power_supply_propval *val)
52{
53 int current_ma;
54 int retval;
55 __u8 request_type;
56
57 if (mfi->charge_type == val->intval) {
58 dev_dbg(&mfi->udev->dev, "charge type %d already set\n",
59 mfi->charge_type);
60 return 0;
61 }
62
63 switch (val->intval) {
64 case POWER_SUPPLY_CHARGE_TYPE_TRICKLE:
65 current_ma = TRICKLE_CURRENT_MA;
66 break;
67 case POWER_SUPPLY_CHARGE_TYPE_FAST:
68 current_ma = FAST_CURRENT_MA;
69 break;
70 default:
71 return -EINVAL;
72 }
73
74 request_type = USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE;
75 retval = usb_control_msg(mfi->udev, usb_sndctrlpipe(mfi->udev, 0),
76 0x40, /* Vendor‐defined power request */
77 request_type,
78 current_ma, /* wValue, current offset */
79 current_ma, /* wIndex, current offset */
80 NULL, 0, USB_CTRL_GET_TIMEOUT);
81 if (retval) {
82 dev_dbg(&mfi->udev->dev, "retval = %d\n", retval);
83 return retval;
84 }
85
86 mfi->charge_type = val->intval;
87
88 return 0;
89}
90
91static int apple_mfi_fc_get_property(struct power_supply *psy,
92 enum power_supply_property psp,
93 union power_supply_propval *val)
94{
95 struct mfi_device *mfi = power_supply_get_drvdata(psy);
96
97 dev_dbg(&mfi->udev->dev, "prop: %d\n", psp);
98
99 switch (psp) {
100 case POWER_SUPPLY_PROP_CHARGE_TYPE:
101 val->intval = mfi->charge_type;
102 break;
103 case POWER_SUPPLY_PROP_SCOPE:
104 val->intval = POWER_SUPPLY_SCOPE_DEVICE;
105 break;
106 default:
107 return -ENODATA;
108 }
109
110 return 0;
111}
112
113static int apple_mfi_fc_set_property(struct power_supply *psy,
114 enum power_supply_property psp,
115 const union power_supply_propval *val)
116{
117 struct mfi_device *mfi = power_supply_get_drvdata(psy);
118 int ret;
119
120 dev_dbg(&mfi->udev->dev, "prop: %d\n", psp);
121
122 ret = pm_runtime_get_sync(&mfi->udev->dev);
123 if (ret < 0) {
124 pm_runtime_put_noidle(&mfi->udev->dev);
125 return ret;
126 }
127
128 switch (psp) {
129 case POWER_SUPPLY_PROP_CHARGE_TYPE:
130 ret = apple_mfi_fc_set_charge_type(mfi, val);
131 break;
132 default:
133 ret = -EINVAL;
134 }
135
136 pm_runtime_mark_last_busy(&mfi->udev->dev);
137 pm_runtime_put_autosuspend(&mfi->udev->dev);
138
139 return ret;
140}
141
142static int apple_mfi_fc_property_is_writeable(struct power_supply *psy,
143 enum power_supply_property psp)
144{
145 switch (psp) {
146 case POWER_SUPPLY_PROP_CHARGE_TYPE:
147 return 1;
148 default:
149 return 0;
150 }
151}
152
153static enum power_supply_property apple_mfi_fc_properties[] = {
154 POWER_SUPPLY_PROP_CHARGE_TYPE,
155 POWER_SUPPLY_PROP_SCOPE
156};
157
158static const struct power_supply_desc apple_mfi_fc_desc = {
159 .name = "apple_mfi_fastcharge",
160 .type = POWER_SUPPLY_TYPE_BATTERY,
161 .properties = apple_mfi_fc_properties,
162 .num_properties = ARRAY_SIZE(apple_mfi_fc_properties),
163 .get_property = apple_mfi_fc_get_property,
164 .set_property = apple_mfi_fc_set_property,
165 .property_is_writeable = apple_mfi_fc_property_is_writeable
166};
167
168static bool mfi_fc_match(struct usb_device *udev)
169{
170 int idProduct;
171
172 idProduct = le16_to_cpu(udev->descriptor.idProduct);
173 /* See comment above mfi_fc_id_table[] */
174 return (idProduct >= 0x1200 && idProduct <= 0x12ff);
175}
176
177static int mfi_fc_probe(struct usb_device *udev)
178{
179 struct power_supply_config battery_cfg = {};
180 struct mfi_device *mfi = NULL;
181 int err;
182
183 if (!mfi_fc_match(udev))
184 return -ENODEV;
185
186 mfi = kzalloc(sizeof(struct mfi_device), GFP_KERNEL);
187 if (!mfi)
188 return -ENOMEM;
189
190 battery_cfg.drv_data = mfi;
191
192 mfi->charge_type = POWER_SUPPLY_CHARGE_TYPE_TRICKLE;
193 mfi->battery = power_supply_register(&udev->dev,
194 &apple_mfi_fc_desc,
195 &battery_cfg);
196 if (IS_ERR(mfi->battery)) {
197 dev_err(&udev->dev, "Can't register battery\n");
198 err = PTR_ERR(mfi->battery);
199 kfree(mfi);
200 return err;
201 }
202
203 mfi->udev = usb_get_dev(udev);
204 dev_set_drvdata(&udev->dev, mfi);
205
206 return 0;
207}
208
209static void mfi_fc_disconnect(struct usb_device *udev)
210{
211 struct mfi_device *mfi;
212
213 mfi = dev_get_drvdata(&udev->dev);
214 if (mfi->battery)
215 power_supply_unregister(mfi->battery);
216 dev_set_drvdata(&udev->dev, NULL);
217 usb_put_dev(mfi->udev);
218 kfree(mfi);
219}
220
221static struct usb_device_driver mfi_fc_driver = {
222 .name = "apple-mfi-fastcharge",
223 .probe = mfi_fc_probe,
224 .disconnect = mfi_fc_disconnect,
225 .id_table = mfi_fc_id_table,
226 .match = mfi_fc_match,
227 .generic_subclass = 1,
228};
229
230static int __init mfi_fc_driver_init(void)
231{
232 return usb_register_device_driver(&mfi_fc_driver, THIS_MODULE);
233}
234
235static void __exit mfi_fc_driver_exit(void)
236{
237 usb_deregister_device_driver(&mfi_fc_driver);
238}
239
240module_init(mfi_fc_driver_init);
241module_exit(mfi_fc_driver_exit);