xref: /linux/drivers/hwmon/powerz.c (revision 9cc8d0ecdd2aad42e377e971e3bb114339df609e)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  Copyright (C) 2023 Thomas Weißschuh <linux@weissschuh.net>
4  */
5 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
6 
7 #include <linux/completion.h>
8 #include <linux/device.h>
9 #include <linux/hwmon.h>
10 #include <linux/module.h>
11 #include <linux/mutex.h>
12 #include <linux/types.h>
13 #include <linux/usb.h>
14 
15 #define DRIVER_NAME	"powerz"
16 #define POWERZ_EP_CMD_OUT	0x01
17 #define POWERZ_EP_DATA_IN	0x81
18 
19 struct powerz_sensor_data {
20 	u8 _unknown_1[8];
21 	__le32 V_bus;
22 	__le32 I_bus;
23 	__le32 V_bus_avg;
24 	__le32 I_bus_avg;
25 	u8 _unknown_2[8];
26 	u8 temp[2];
27 	__le16 V_cc1;
28 	__le16 V_cc2;
29 	__le16 V_dp;
30 	__le16 V_dm;
31 	__le16 V_dd;
32 	u8 _unknown_3[4];
33 } __packed;
34 
35 struct powerz_priv {
36 	char transfer_buffer[64];	/* first member to satisfy DMA alignment */
37 	struct mutex mutex;
38 	struct completion completion;
39 	struct urb *urb;
40 	int status;
41 };
42 
43 static const struct hwmon_channel_info *const powerz_info[] = {
44 	HWMON_CHANNEL_INFO(in,
45 			   HWMON_I_INPUT | HWMON_I_LABEL | HWMON_I_AVERAGE,
46 			   HWMON_I_INPUT | HWMON_I_LABEL,
47 			   HWMON_I_INPUT | HWMON_I_LABEL,
48 			   HWMON_I_INPUT | HWMON_I_LABEL,
49 			   HWMON_I_INPUT | HWMON_I_LABEL,
50 			   HWMON_I_INPUT | HWMON_I_LABEL),
51 	HWMON_CHANNEL_INFO(curr,
52 			   HWMON_C_INPUT | HWMON_C_LABEL | HWMON_C_AVERAGE),
53 	    HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT | HWMON_T_LABEL),
54 	NULL
55 };
56 
57 static int powerz_read_string(struct device *dev, enum hwmon_sensor_types type,
58 			      u32 attr, int channel, const char **str)
59 {
60 	if (type == hwmon_curr && attr == hwmon_curr_label) {
61 		*str = "IBUS";
62 	} else if (type == hwmon_in && attr == hwmon_in_label) {
63 		if (channel == 0)
64 			*str = "VBUS";
65 		else if (channel == 1)
66 			*str = "VCC1";
67 		else if (channel == 2)
68 			*str = "VCC2";
69 		else if (channel == 3)
70 			*str = "VDP";
71 		else if (channel == 4)
72 			*str = "VDM";
73 		else if (channel == 5)
74 			*str = "VDD";
75 		else
76 			return -EOPNOTSUPP;
77 	} else if (type == hwmon_temp && attr == hwmon_temp_label) {
78 		*str = "TEMP";
79 	} else {
80 		return -EOPNOTSUPP;
81 	}
82 
83 	return 0;
84 }
85 
86 static void powerz_usb_data_complete(struct urb *urb)
87 {
88 	struct powerz_priv *priv = urb->context;
89 
90 	complete(&priv->completion);
91 }
92 
93 static void powerz_usb_cmd_complete(struct urb *urb)
94 {
95 	struct powerz_priv *priv = urb->context;
96 
97 	usb_fill_bulk_urb(urb, urb->dev,
98 			  usb_rcvbulkpipe(urb->dev, POWERZ_EP_DATA_IN),
99 			  priv->transfer_buffer, sizeof(priv->transfer_buffer),
100 			  powerz_usb_data_complete, priv);
101 
102 	priv->status = usb_submit_urb(urb, GFP_ATOMIC);
103 	if (priv->status)
104 		complete(&priv->completion);
105 }
106 
107 static int powerz_read_data(struct usb_device *udev, struct powerz_priv *priv)
108 {
109 	int ret;
110 
111 	priv->status = -ETIMEDOUT;
112 	reinit_completion(&priv->completion);
113 
114 	priv->transfer_buffer[0] = 0x0c;
115 	priv->transfer_buffer[1] = 0x00;
116 	priv->transfer_buffer[2] = 0x02;
117 	priv->transfer_buffer[3] = 0x00;
118 
119 	usb_fill_bulk_urb(priv->urb, udev,
120 			  usb_sndbulkpipe(udev, POWERZ_EP_CMD_OUT),
121 			  priv->transfer_buffer, 4, powerz_usb_cmd_complete,
122 			  priv);
123 	ret = usb_submit_urb(priv->urb, GFP_KERNEL);
124 	if (ret)
125 		return ret;
126 
127 	if (!wait_for_completion_interruptible_timeout
128 	    (&priv->completion, msecs_to_jiffies(5))) {
129 		usb_kill_urb(priv->urb);
130 		return -EIO;
131 	}
132 
133 	if (priv->urb->actual_length < sizeof(struct powerz_sensor_data))
134 		return -EIO;
135 
136 	return priv->status;
137 }
138 
139 static int powerz_read(struct device *dev, enum hwmon_sensor_types type,
140 		       u32 attr, int channel, long *val)
141 {
142 	struct usb_interface *intf = to_usb_interface(dev->parent);
143 	struct usb_device *udev = interface_to_usbdev(intf);
144 	struct powerz_priv *priv = usb_get_intfdata(intf);
145 	struct powerz_sensor_data *data;
146 	int ret;
147 
148 	if (!priv)
149 		return -EIO;	/* disconnected */
150 
151 	mutex_lock(&priv->mutex);
152 	ret = powerz_read_data(udev, priv);
153 	if (ret)
154 		goto out;
155 
156 	data = (struct powerz_sensor_data *)priv->transfer_buffer;
157 
158 	if (type == hwmon_curr) {
159 		if (attr == hwmon_curr_input)
160 			*val = ((s32)le32_to_cpu(data->I_bus)) / 1000;
161 		else if (attr == hwmon_curr_average)
162 			*val = ((s32)le32_to_cpu(data->I_bus_avg)) / 1000;
163 		else
164 			ret = -EOPNOTSUPP;
165 	} else if (type == hwmon_in) {
166 		if (attr == hwmon_in_input) {
167 			if (channel == 0)
168 				*val = le32_to_cpu(data->V_bus) / 1000;
169 			else if (channel == 1)
170 				*val = le16_to_cpu(data->V_cc1) / 10;
171 			else if (channel == 2)
172 				*val = le16_to_cpu(data->V_cc2) / 10;
173 			else if (channel == 3)
174 				*val = le16_to_cpu(data->V_dp) / 10;
175 			else if (channel == 4)
176 				*val = le16_to_cpu(data->V_dm) / 10;
177 			else if (channel == 5)
178 				*val = le16_to_cpu(data->V_dd) / 10;
179 			else
180 				ret = -EOPNOTSUPP;
181 		} else if (attr == hwmon_in_average && channel == 0) {
182 			*val = le32_to_cpu(data->V_bus_avg) / 1000;
183 		} else {
184 			ret = -EOPNOTSUPP;
185 		}
186 	} else if (type == hwmon_temp && attr == hwmon_temp_input) {
187 		*val = data->temp[1] * 2000 + data->temp[0] * 1000 / 128;
188 	} else {
189 		ret = -EOPNOTSUPP;
190 	}
191 
192 out:
193 	mutex_unlock(&priv->mutex);
194 	return ret;
195 }
196 
197 static const struct hwmon_ops powerz_hwmon_ops = {
198 	.visible = 0444,
199 	.read = powerz_read,
200 	.read_string = powerz_read_string,
201 };
202 
203 static const struct hwmon_chip_info powerz_chip_info = {
204 	.ops = &powerz_hwmon_ops,
205 	.info = powerz_info,
206 };
207 
208 static int powerz_probe(struct usb_interface *intf,
209 			const struct usb_device_id *id)
210 {
211 	struct powerz_priv *priv;
212 	struct device *hwmon_dev;
213 	struct device *parent;
214 
215 	parent = &intf->dev;
216 
217 	priv = devm_kzalloc(parent, sizeof(*priv), GFP_KERNEL);
218 	if (!priv)
219 		return -ENOMEM;
220 
221 	priv->urb = usb_alloc_urb(0, GFP_KERNEL);
222 	if (!priv->urb)
223 		return -ENOMEM;
224 	mutex_init(&priv->mutex);
225 	init_completion(&priv->completion);
226 
227 	hwmon_dev =
228 	    devm_hwmon_device_register_with_info(parent, DRIVER_NAME, priv,
229 						 &powerz_chip_info, NULL);
230 	if (IS_ERR(hwmon_dev)) {
231 		usb_free_urb(priv->urb);
232 		return PTR_ERR(hwmon_dev);
233 	}
234 
235 	usb_set_intfdata(intf, priv);
236 
237 	return 0;
238 }
239 
240 static void powerz_disconnect(struct usb_interface *intf)
241 {
242 	struct powerz_priv *priv = usb_get_intfdata(intf);
243 
244 	mutex_lock(&priv->mutex);
245 	usb_kill_urb(priv->urb);
246 	usb_free_urb(priv->urb);
247 	mutex_unlock(&priv->mutex);
248 }
249 
250 static const struct usb_device_id powerz_id_table[] = {
251 	{ USB_DEVICE_INTERFACE_NUMBER(0x5FC9, 0x0061, 0x00) },	/* ChargerLAB POWER-Z KM002C */
252 	{ USB_DEVICE_INTERFACE_NUMBER(0x5FC9, 0x0063, 0x00) },	/* ChargerLAB POWER-Z KM003C */
253 	{ }
254 };
255 
256 MODULE_DEVICE_TABLE(usb, powerz_id_table);
257 
258 static struct usb_driver powerz_driver = {
259 	.name = DRIVER_NAME,
260 	.id_table = powerz_id_table,
261 	.probe = powerz_probe,
262 	.disconnect = powerz_disconnect,
263 };
264 
265 module_usb_driver(powerz_driver);
266 
267 MODULE_LICENSE("GPL");
268 MODULE_AUTHOR("Thomas Weißschuh <linux@weissschuh.net>");
269 MODULE_DESCRIPTION("ChargerLAB POWER-Z USB-C tester");
270