xref: /linux/drivers/usb/misc/apple-mfi-fastcharge.c (revision cdd38c5f1ce4398ec58fec95904b75824daab7b5)
1249fa821SBastien Nocera // SPDX-License-Identifier: GPL-2.0+
2249fa821SBastien Nocera /*
3249fa821SBastien Nocera  * Fast-charge control for Apple "MFi" devices
4249fa821SBastien Nocera  *
5249fa821SBastien Nocera  * Copyright (C) 2019 Bastien Nocera <hadess@hadess.net>
6249fa821SBastien Nocera  */
7249fa821SBastien Nocera 
8249fa821SBastien Nocera /* Standard include files */
9249fa821SBastien Nocera #include <linux/module.h>
10249fa821SBastien Nocera #include <linux/power_supply.h>
11249fa821SBastien Nocera #include <linux/slab.h>
12249fa821SBastien Nocera #include <linux/usb.h>
13249fa821SBastien Nocera 
14249fa821SBastien Nocera MODULE_AUTHOR("Bastien Nocera <hadess@hadess.net>");
15249fa821SBastien Nocera MODULE_DESCRIPTION("Fast-charge control for Apple \"MFi\" devices");
16249fa821SBastien Nocera MODULE_LICENSE("GPL");
17249fa821SBastien Nocera 
18249fa821SBastien Nocera #define TRICKLE_CURRENT_MA		0
19249fa821SBastien Nocera #define FAST_CURRENT_MA			2500
20249fa821SBastien Nocera 
21249fa821SBastien Nocera #define APPLE_VENDOR_ID			0x05ac	/* Apple */
22249fa821SBastien Nocera 
23249fa821SBastien Nocera /* The product ID is defined as starting with 0x12nn, as per the
24249fa821SBastien Nocera  * "Choosing an Apple Device USB Configuration" section in
25249fa821SBastien Nocera  * release R9 (2012) of the "MFi Accessory Hardware Specification"
26249fa821SBastien Nocera  *
27249fa821SBastien Nocera  * To distinguish an Apple device, a USB host can check the device
28249fa821SBastien Nocera  * descriptor of attached USB devices for the following fields:
29249fa821SBastien Nocera  * ■ Vendor ID: 0x05AC
30249fa821SBastien Nocera  * ■ Product ID: 0x12nn
31249fa821SBastien Nocera  *
32249fa821SBastien Nocera  * Those checks will be done in .match() and .probe().
33249fa821SBastien Nocera  */
34249fa821SBastien Nocera 
35249fa821SBastien Nocera static const struct usb_device_id mfi_fc_id_table[] = {
36249fa821SBastien Nocera 	{ .idVendor = APPLE_VENDOR_ID,
37249fa821SBastien Nocera 	  .match_flags = USB_DEVICE_ID_MATCH_VENDOR },
38249fa821SBastien Nocera 	{},
39249fa821SBastien Nocera };
40249fa821SBastien Nocera 
41249fa821SBastien Nocera MODULE_DEVICE_TABLE(usb, mfi_fc_id_table);
42249fa821SBastien Nocera 
43249fa821SBastien Nocera /* Driver-local specific stuff */
44249fa821SBastien Nocera struct mfi_device {
45249fa821SBastien Nocera 	struct usb_device *udev;
46249fa821SBastien Nocera 	struct power_supply *battery;
47249fa821SBastien Nocera 	int charge_type;
48249fa821SBastien Nocera };
49249fa821SBastien Nocera 
apple_mfi_fc_set_charge_type(struct mfi_device * mfi,const union power_supply_propval * val)50249fa821SBastien Nocera static int apple_mfi_fc_set_charge_type(struct mfi_device *mfi,
51249fa821SBastien Nocera 					const union power_supply_propval *val)
52249fa821SBastien Nocera {
53249fa821SBastien Nocera 	int current_ma;
54249fa821SBastien Nocera 	int retval;
55249fa821SBastien Nocera 	__u8 request_type;
56249fa821SBastien Nocera 
57249fa821SBastien Nocera 	if (mfi->charge_type == val->intval) {
58249fa821SBastien Nocera 		dev_dbg(&mfi->udev->dev, "charge type %d already set\n",
59249fa821SBastien Nocera 				mfi->charge_type);
60249fa821SBastien Nocera 		return 0;
61249fa821SBastien Nocera 	}
62249fa821SBastien Nocera 
63249fa821SBastien Nocera 	switch (val->intval) {
64249fa821SBastien Nocera 	case POWER_SUPPLY_CHARGE_TYPE_TRICKLE:
65249fa821SBastien Nocera 		current_ma = TRICKLE_CURRENT_MA;
66249fa821SBastien Nocera 		break;
67249fa821SBastien Nocera 	case POWER_SUPPLY_CHARGE_TYPE_FAST:
68249fa821SBastien Nocera 		current_ma = FAST_CURRENT_MA;
69249fa821SBastien Nocera 		break;
70249fa821SBastien Nocera 	default:
71249fa821SBastien Nocera 		return -EINVAL;
72249fa821SBastien Nocera 	}
73249fa821SBastien Nocera 
74249fa821SBastien Nocera 	request_type = USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE;
75249fa821SBastien Nocera 	retval = usb_control_msg(mfi->udev, usb_sndctrlpipe(mfi->udev, 0),
76249fa821SBastien Nocera 				 0x40, /* Vendor‐defined power request */
77249fa821SBastien Nocera 				 request_type,
78249fa821SBastien Nocera 				 current_ma, /* wValue, current offset */
79249fa821SBastien Nocera 				 current_ma, /* wIndex, current offset */
80249fa821SBastien Nocera 				 NULL, 0, USB_CTRL_GET_TIMEOUT);
81249fa821SBastien Nocera 	if (retval) {
82249fa821SBastien Nocera 		dev_dbg(&mfi->udev->dev, "retval = %d\n", retval);
83249fa821SBastien Nocera 		return retval;
84249fa821SBastien Nocera 	}
85249fa821SBastien Nocera 
86249fa821SBastien Nocera 	mfi->charge_type = val->intval;
87249fa821SBastien Nocera 
88249fa821SBastien Nocera 	return 0;
89249fa821SBastien Nocera }
90249fa821SBastien Nocera 
apple_mfi_fc_get_property(struct power_supply * psy,enum power_supply_property psp,union power_supply_propval * val)91249fa821SBastien Nocera static int apple_mfi_fc_get_property(struct power_supply *psy,
92249fa821SBastien Nocera 		enum power_supply_property psp,
93249fa821SBastien Nocera 		union power_supply_propval *val)
94249fa821SBastien Nocera {
95249fa821SBastien Nocera 	struct mfi_device *mfi = power_supply_get_drvdata(psy);
96249fa821SBastien Nocera 
97249fa821SBastien Nocera 	dev_dbg(&mfi->udev->dev, "prop: %d\n", psp);
98249fa821SBastien Nocera 
99249fa821SBastien Nocera 	switch (psp) {
100249fa821SBastien Nocera 	case POWER_SUPPLY_PROP_CHARGE_TYPE:
101249fa821SBastien Nocera 		val->intval = mfi->charge_type;
102249fa821SBastien Nocera 		break;
103249fa821SBastien Nocera 	case POWER_SUPPLY_PROP_SCOPE:
104249fa821SBastien Nocera 		val->intval = POWER_SUPPLY_SCOPE_DEVICE;
105249fa821SBastien Nocera 		break;
106249fa821SBastien Nocera 	default:
107249fa821SBastien Nocera 		return -ENODATA;
108249fa821SBastien Nocera 	}
109249fa821SBastien Nocera 
110249fa821SBastien Nocera 	return 0;
111249fa821SBastien Nocera }
112249fa821SBastien Nocera 
apple_mfi_fc_set_property(struct power_supply * psy,enum power_supply_property psp,const union power_supply_propval * val)113249fa821SBastien Nocera static int apple_mfi_fc_set_property(struct power_supply *psy,
114249fa821SBastien Nocera 		enum power_supply_property psp,
115249fa821SBastien Nocera 		const union power_supply_propval *val)
116249fa821SBastien Nocera {
117249fa821SBastien Nocera 	struct mfi_device *mfi = power_supply_get_drvdata(psy);
118249fa821SBastien Nocera 	int ret;
119249fa821SBastien Nocera 
120249fa821SBastien Nocera 	dev_dbg(&mfi->udev->dev, "prop: %d\n", psp);
121249fa821SBastien Nocera 
122249fa821SBastien Nocera 	ret = pm_runtime_get_sync(&mfi->udev->dev);
12300bd6bcaSZhang Qilong 	if (ret < 0) {
12400bd6bcaSZhang Qilong 		pm_runtime_put_noidle(&mfi->udev->dev);
125249fa821SBastien Nocera 		return ret;
12600bd6bcaSZhang Qilong 	}
127249fa821SBastien Nocera 
128249fa821SBastien Nocera 	switch (psp) {
129249fa821SBastien Nocera 	case POWER_SUPPLY_PROP_CHARGE_TYPE:
130249fa821SBastien Nocera 		ret = apple_mfi_fc_set_charge_type(mfi, val);
131249fa821SBastien Nocera 		break;
132249fa821SBastien Nocera 	default:
133249fa821SBastien Nocera 		ret = -EINVAL;
134249fa821SBastien Nocera 	}
135249fa821SBastien Nocera 
136249fa821SBastien Nocera 	pm_runtime_mark_last_busy(&mfi->udev->dev);
137249fa821SBastien Nocera 	pm_runtime_put_autosuspend(&mfi->udev->dev);
138249fa821SBastien Nocera 
139249fa821SBastien Nocera 	return ret;
140249fa821SBastien Nocera }
141249fa821SBastien Nocera 
apple_mfi_fc_property_is_writeable(struct power_supply * psy,enum power_supply_property psp)142249fa821SBastien Nocera static int apple_mfi_fc_property_is_writeable(struct power_supply *psy,
143249fa821SBastien Nocera 					      enum power_supply_property psp)
144249fa821SBastien Nocera {
145249fa821SBastien Nocera 	switch (psp) {
146249fa821SBastien Nocera 	case POWER_SUPPLY_PROP_CHARGE_TYPE:
147249fa821SBastien Nocera 		return 1;
148249fa821SBastien Nocera 	default:
149249fa821SBastien Nocera 		return 0;
150249fa821SBastien Nocera 	}
151249fa821SBastien Nocera }
152249fa821SBastien Nocera 
153249fa821SBastien Nocera static enum power_supply_property apple_mfi_fc_properties[] = {
154249fa821SBastien Nocera 	POWER_SUPPLY_PROP_CHARGE_TYPE,
155249fa821SBastien Nocera 	POWER_SUPPLY_PROP_SCOPE
156249fa821SBastien Nocera };
157249fa821SBastien Nocera 
158249fa821SBastien Nocera static const struct power_supply_desc apple_mfi_fc_desc = {
159249fa821SBastien Nocera 	.name                   = "apple_mfi_fastcharge",
160249fa821SBastien Nocera 	.type                   = POWER_SUPPLY_TYPE_BATTERY,
161249fa821SBastien Nocera 	.properties             = apple_mfi_fc_properties,
162249fa821SBastien Nocera 	.num_properties         = ARRAY_SIZE(apple_mfi_fc_properties),
163249fa821SBastien Nocera 	.get_property           = apple_mfi_fc_get_property,
164249fa821SBastien Nocera 	.set_property           = apple_mfi_fc_set_property,
165249fa821SBastien Nocera 	.property_is_writeable  = apple_mfi_fc_property_is_writeable
166249fa821SBastien Nocera };
167249fa821SBastien Nocera 
mfi_fc_match(struct usb_device * udev)1680cb68669SBastien Nocera static bool mfi_fc_match(struct usb_device *udev)
1690cb68669SBastien Nocera {
1700cb68669SBastien Nocera 	int idProduct;
1710cb68669SBastien Nocera 
1720cb68669SBastien Nocera 	idProduct = le16_to_cpu(udev->descriptor.idProduct);
1730cb68669SBastien Nocera 	/* See comment above mfi_fc_id_table[] */
1740cb68669SBastien Nocera 	return (idProduct >= 0x1200 && idProduct <= 0x12ff);
1750cb68669SBastien Nocera }
1760cb68669SBastien Nocera 
mfi_fc_probe(struct usb_device * udev)177249fa821SBastien Nocera static int mfi_fc_probe(struct usb_device *udev)
178249fa821SBastien Nocera {
179249fa821SBastien Nocera 	struct power_supply_config battery_cfg = {};
180249fa821SBastien Nocera 	struct mfi_device *mfi = NULL;
181*cf5fbe02SDan Carpenter 	int err;
182249fa821SBastien Nocera 
1830cb68669SBastien Nocera 	if (!mfi_fc_match(udev))
184249fa821SBastien Nocera 		return -ENODEV;
185249fa821SBastien Nocera 
186249fa821SBastien Nocera 	mfi = kzalloc(sizeof(struct mfi_device), GFP_KERNEL);
187b0eec52fSLucas Tanure 	if (!mfi)
188b0eec52fSLucas Tanure 		return -ENOMEM;
189249fa821SBastien Nocera 
190249fa821SBastien Nocera 	battery_cfg.drv_data = mfi;
191249fa821SBastien Nocera 
192249fa821SBastien Nocera 	mfi->charge_type = POWER_SUPPLY_CHARGE_TYPE_TRICKLE;
193249fa821SBastien Nocera 	mfi->battery = power_supply_register(&udev->dev,
194249fa821SBastien Nocera 						&apple_mfi_fc_desc,
195249fa821SBastien Nocera 						&battery_cfg);
196249fa821SBastien Nocera 	if (IS_ERR(mfi->battery)) {
197249fa821SBastien Nocera 		dev_err(&udev->dev, "Can't register battery\n");
198*cf5fbe02SDan Carpenter 		err = PTR_ERR(mfi->battery);
199b0eec52fSLucas Tanure 		kfree(mfi);
200*cf5fbe02SDan Carpenter 		return err;
201249fa821SBastien Nocera 	}
202249fa821SBastien Nocera 
203249fa821SBastien Nocera 	mfi->udev = usb_get_dev(udev);
204249fa821SBastien Nocera 	dev_set_drvdata(&udev->dev, mfi);
205249fa821SBastien Nocera 
206249fa821SBastien Nocera 	return 0;
207249fa821SBastien Nocera }
208249fa821SBastien Nocera 
mfi_fc_disconnect(struct usb_device * udev)209249fa821SBastien Nocera static void mfi_fc_disconnect(struct usb_device *udev)
210249fa821SBastien Nocera {
211249fa821SBastien Nocera 	struct mfi_device *mfi;
212249fa821SBastien Nocera 
213249fa821SBastien Nocera 	mfi = dev_get_drvdata(&udev->dev);
214249fa821SBastien Nocera 	if (mfi->battery)
215249fa821SBastien Nocera 		power_supply_unregister(mfi->battery);
216249fa821SBastien Nocera 	dev_set_drvdata(&udev->dev, NULL);
217249fa821SBastien Nocera 	usb_put_dev(mfi->udev);
218249fa821SBastien Nocera 	kfree(mfi);
219249fa821SBastien Nocera }
220249fa821SBastien Nocera 
221249fa821SBastien Nocera static struct usb_device_driver mfi_fc_driver = {
222249fa821SBastien Nocera 	.name =		"apple-mfi-fastcharge",
223249fa821SBastien Nocera 	.probe =	mfi_fc_probe,
224249fa821SBastien Nocera 	.disconnect =	mfi_fc_disconnect,
225249fa821SBastien Nocera 	.id_table =	mfi_fc_id_table,
2260cb68669SBastien Nocera 	.match =	mfi_fc_match,
227249fa821SBastien Nocera 	.generic_subclass = 1,
228249fa821SBastien Nocera };
229249fa821SBastien Nocera 
mfi_fc_driver_init(void)230249fa821SBastien Nocera static int __init mfi_fc_driver_init(void)
231249fa821SBastien Nocera {
232249fa821SBastien Nocera 	return usb_register_device_driver(&mfi_fc_driver, THIS_MODULE);
233249fa821SBastien Nocera }
234249fa821SBastien Nocera 
mfi_fc_driver_exit(void)235249fa821SBastien Nocera static void __exit mfi_fc_driver_exit(void)
236249fa821SBastien Nocera {
237249fa821SBastien Nocera 	usb_deregister_device_driver(&mfi_fc_driver);
238249fa821SBastien Nocera }
239249fa821SBastien Nocera 
240249fa821SBastien Nocera module_init(mfi_fc_driver_init);
241249fa821SBastien Nocera module_exit(mfi_fc_driver_exit);
242