drivers/hwmon/powerz.c

   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");