drivers/firmware/arm_scmi/sensors.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * System Control and Management Interface (SCMI) Sensor Protocol
   4  *
   5  * Copyright (C) 2018 ARM Ltd.
   6  */
   7
   8 #include "common.h"
   9
  10 enum scmi_sensor_protocol_cmd {
  11         SENSOR_DESCRIPTION_GET = 0x3,
  12         SENSOR_CONFIG_SET = 0x4,
  13         SENSOR_TRIP_POINT_SET = 0x5,
  14         SENSOR_READING_GET = 0x6,
  15 };
  16
  17 struct scmi_msg_resp_sensor_attributes {
  18         __le16 num_sensors;
  19         u8 max_requests;
  20         u8 reserved;
  21         __le32 reg_addr_low;
  22         __le32 reg_addr_high;
  23         __le32 reg_size;
  24 };
  25
  26 struct scmi_msg_resp_sensor_description {
  27         __le16 num_returned;
  28         __le16 num_remaining;
  29         struct {
  30                 __le32 id;
  31                 __le32 attributes_low;
  32 #define SUPPORTS_ASYNC_READ(x)  ((x) & BIT(31))
  33 #define NUM_TRIP_POINTS(x)      ((x) & 0xff)
  34                 __le32 attributes_high;
  35 #define SENSOR_TYPE(x)          ((x) & 0xff)
  36 #define SENSOR_SCALE(x)         (((x) >> 11) & 0x1f)
  37 #define SENSOR_UPDATE_SCALE(x)  (((x) >> 22) & 0x1f)
  38 #define SENSOR_UPDATE_BASE(x)   (((x) >> 27) & 0x1f)
  39                     u8 name[SCMI_MAX_STR_SIZE];
  40         } desc[0];
  41 };
  42
  43 struct scmi_msg_set_sensor_config {
  44         __le32 id;
  45         __le32 event_control;
  46 };
  47
  48 struct scmi_msg_set_sensor_trip_point {
  49         __le32 id;
  50         __le32 event_control;
  51 #define SENSOR_TP_EVENT_MASK    (0x3)
  52 #define SENSOR_TP_DISABLED      0x0
  53 #define SENSOR_TP_POSITIVE      0x1
  54 #define SENSOR_TP_NEGATIVE      0x2
  55 #define SENSOR_TP_BOTH          0x3
  56 #define SENSOR_TP_ID(x)         (((x) & 0xff) << 4)
  57         __le32 value_low;
  58         __le32 value_high;
  59 };
  60
  61 struct scmi_msg_sensor_reading_get {
  62         __le32 id;
  63         __le32 flags;
  64 #define SENSOR_READ_ASYNC       BIT(0)
  65 };
  66
  67 struct sensors_info {
  68         int num_sensors;
  69         int max_requests;
  70         u64 reg_addr;
  71         u32 reg_size;
  72         struct scmi_sensor_info *sensors;
  73 };
  74
  75 static int scmi_sensor_attributes_get(const struct scmi_handle *handle,
  76                                       struct sensors_info *si)
  77 {
  78         int ret;
  79         struct scmi_xfer *t;
  80         struct scmi_msg_resp_sensor_attributes *attr;
  81
  82         ret = scmi_xfer_get_init(handle, PROTOCOL_ATTRIBUTES,
  83                                  SCMI_PROTOCOL_SENSOR, 0, sizeof(*attr), &t);
  84         if (ret)
  85                 return ret;
  86
  87         attr = t->rx.buf;
  88
  89         ret = scmi_do_xfer(handle, t);
  90         if (!ret) {
  91                 si->num_sensors = le16_to_cpu(attr->num_sensors);
  92                 si->max_requests = attr->max_requests;
  93                 si->reg_addr = le32_to_cpu(attr->reg_addr_low) |
  94                                 (u64)le32_to_cpu(attr->reg_addr_high) << 32;
  95                 si->reg_size = le32_to_cpu(attr->reg_size);
  96         }
  97
  98         scmi_xfer_put(handle, t);
  99         return ret;
 100 }
 101
 102 static int scmi_sensor_description_get(const struct scmi_handle *handle,
 103                                        struct sensors_info *si)
 104 {
 105         int ret, cnt;
 106         u32 desc_index = 0;
 107         u16 num_returned, num_remaining;
 108         struct scmi_xfer *t;
 109         struct scmi_msg_resp_sensor_description *buf;
 110
 111         ret = scmi_xfer_get_init(handle, SENSOR_DESCRIPTION_GET,
 112                                  SCMI_PROTOCOL_SENSOR, sizeof(__le32), 0, &t);
 113         if (ret)
 114                 return ret;
 115
 116         buf = t->rx.buf;
 117
 118         do {
 119                 /* Set the number of sensors to be skipped/already read */
 120                 *(__le32 *)t->tx.buf = cpu_to_le32(desc_index);
 121
 122                 ret = scmi_do_xfer(handle, t);
 123                 if (ret)
 124                         break;
 125
 126                 num_returned = le16_to_cpu(buf->num_returned);
 127                 num_remaining = le16_to_cpu(buf->num_remaining);
 128
 129                 if (desc_index + num_returned > si->num_sensors) {
 130                         dev_err(handle->dev, "No. of sensors can't exceed %d",
 131                                 si->num_sensors);
 132                         break;
 133                 }
 134
 135                 for (cnt = 0; cnt < num_returned; cnt++) {
 136                         u32 attrh;
 137                         struct scmi_sensor_info *s;
 138
 139                         attrh = le32_to_cpu(buf->desc[cnt].attributes_high);
 140                         s = &si->sensors[desc_index + cnt];
 141                         s->id = le32_to_cpu(buf->desc[cnt].id);
 142                         s->type = SENSOR_TYPE(attrh);
 143                         strlcpy(s->name, buf->desc[cnt].name, SCMI_MAX_STR_SIZE);
 144                 }
 145
 146                 desc_index += num_returned;
 147                 /*
 148                  * check for both returned and remaining to avoid infinite
 149                  * loop due to buggy firmware
 150                  */
 151         } while (num_returned && num_remaining);
 152
 153         scmi_xfer_put(handle, t);
 154         return ret;
 155 }
 156
 157 static int
 158 scmi_sensor_configuration_set(const struct scmi_handle *handle, u32 sensor_id)
 159 {
 160         int ret;
 161         u32 evt_cntl = BIT(0);
 162         struct scmi_xfer *t;
 163         struct scmi_msg_set_sensor_config *cfg;
 164
 165         ret = scmi_xfer_get_init(handle, SENSOR_CONFIG_SET,
 166                                  SCMI_PROTOCOL_SENSOR, sizeof(*cfg), 0, &t);
 167         if (ret)
 168                 return ret;
 169
 170         cfg = t->tx.buf;
 171         cfg->id = cpu_to_le32(sensor_id);
 172         cfg->event_control = cpu_to_le32(evt_cntl);
 173
 174         ret = scmi_do_xfer(handle, t);
 175
 176         scmi_xfer_put(handle, t);
 177         return ret;
 178 }
 179
 180 static int scmi_sensor_trip_point_set(const struct scmi_handle *handle,
 181                                       u32 sensor_id, u8 trip_id, u64 trip_value)
 182 {
 183         int ret;
 184         u32 evt_cntl = SENSOR_TP_BOTH;
 185         struct scmi_xfer *t;
 186         struct scmi_msg_set_sensor_trip_point *trip;
 187
 188         ret = scmi_xfer_get_init(handle, SENSOR_TRIP_POINT_SET,
 189                                  SCMI_PROTOCOL_SENSOR, sizeof(*trip), 0, &t);
 190         if (ret)
 191                 return ret;
 192
 193         trip = t->tx.buf;
 194         trip->id = cpu_to_le32(sensor_id);
 195         trip->event_control = cpu_to_le32(evt_cntl | SENSOR_TP_ID(trip_id));
 196         trip->value_low = cpu_to_le32(trip_value & 0xffffffff);
 197         trip->value_high = cpu_to_le32(trip_value >> 32);
 198
 199         ret = scmi_do_xfer(handle, t);
 200
 201         scmi_xfer_put(handle, t);
 202         return ret;
 203 }
 204
 205 static int scmi_sensor_reading_get(const struct scmi_handle *handle,
 206                                    u32 sensor_id, bool async, u64 *value)
 207 {
 208         int ret;
 209         struct scmi_xfer *t;
 210         struct scmi_msg_sensor_reading_get *sensor;
 211
 212         ret = scmi_xfer_get_init(handle, SENSOR_READING_GET,
 213                                  SCMI_PROTOCOL_SENSOR, sizeof(*sensor),
 214                                  sizeof(u64), &t);
 215         if (ret)
 216                 return ret;
 217
 218         sensor = t->tx.buf;
 219         sensor->id = cpu_to_le32(sensor_id);
 220         sensor->flags = cpu_to_le32(async ? SENSOR_READ_ASYNC : 0);
 221
 222         ret = scmi_do_xfer(handle, t);
 223         if (!ret) {
 224                 __le32 *pval = t->rx.buf;
 225
 226                 *value = le32_to_cpu(*pval);
 227                 *value |= (u64)le32_to_cpu(*(pval + 1)) << 32;
 228         }
 229
 230         scmi_xfer_put(handle, t);
 231         return ret;
 232 }
 233
 234 static const struct scmi_sensor_info *
 235 scmi_sensor_info_get(const struct scmi_handle *handle, u32 sensor_id)
 236 {
 237         struct sensors_info *si = handle->sensor_priv;
 238
 239         return si->sensors + sensor_id;
 240 }
 241
 242 static int scmi_sensor_count_get(const struct scmi_handle *handle)
 243 {
 244         struct sensors_info *si = handle->sensor_priv;
 245
 246         return si->num_sensors;
 247 }
 248
 249 static struct scmi_sensor_ops sensor_ops = {
 250         .count_get = scmi_sensor_count_get,
 251         .info_get = scmi_sensor_info_get,
 252         .configuration_set = scmi_sensor_configuration_set,
 253         .trip_point_set = scmi_sensor_trip_point_set,
 254         .reading_get = scmi_sensor_reading_get,
 255 };
 256
 257 static int scmi_sensors_protocol_init(struct scmi_handle *handle)
 258 {
 259         u32 version;
 260         struct sensors_info *sinfo;
 261
 262         scmi_version_get(handle, SCMI_PROTOCOL_SENSOR, &version);
 263
 264         dev_dbg(handle->dev, "Sensor Version %d.%d\n",
 265                 PROTOCOL_REV_MAJOR(version), PROTOCOL_REV_MINOR(version));
 266
 267         sinfo = devm_kzalloc(handle->dev, sizeof(*sinfo), GFP_KERNEL);
 268         if (!sinfo)
 269                 return -ENOMEM;
 270
 271         scmi_sensor_attributes_get(handle, sinfo);
 272
 273         sinfo->sensors = devm_kcalloc(handle->dev, sinfo->num_sensors,
 274                                       sizeof(*sinfo->sensors), GFP_KERNEL);
 275         if (!sinfo->sensors)
 276                 return -ENOMEM;
 277
 278         scmi_sensor_description_get(handle, sinfo);
 279
 280         handle->sensor_ops = &sensor_ops;
 281         handle->sensor_priv = sinfo;
 282
 283         return 0;
 284 }
 285
 286 static int __init scmi_sensors_init(void)
 287 {
 288         return scmi_protocol_register(SCMI_PROTOCOL_SENSOR,
 289                                       &scmi_sensors_protocol_init);
 290 }
 291 subsys_initcall(scmi_sensors_init);