drivers/firmware/arm_scmi/base.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * System Control and Management Interface (SCMI) Base Protocol
   4  *
   5  * Copyright (C) 2018 ARM Ltd.
   6  */
   7
   8 #include "common.h"
   9
  10 enum scmi_base_protocol_cmd {
  11         BASE_DISCOVER_VENDOR = 0x3,
  12         BASE_DISCOVER_SUB_VENDOR = 0x4,
  13         BASE_DISCOVER_IMPLEMENT_VERSION = 0x5,
  14         BASE_DISCOVER_LIST_PROTOCOLS = 0x6,
  15         BASE_DISCOVER_AGENT = 0x7,
  16         BASE_NOTIFY_ERRORS = 0x8,
  17 };
  18
  19 struct scmi_msg_resp_base_attributes {
  20         u8 num_protocols;
  21         u8 num_agents;
  22         __le16 reserved;
  23 };
  24
  25 /**
  26  * scmi_base_attributes_get() - gets the implementation details
  27  *      that are associated with the base protocol.
  28  *
  29  * @handle: SCMI entity handle
  30  *
  31  * Return: 0 on success, else appropriate SCMI error.
  32  */
  33 static int scmi_base_attributes_get(const struct scmi_handle *handle)
  34 {
  35         int ret;
  36         struct scmi_xfer *t;
  37         struct scmi_msg_resp_base_attributes *attr_info;
  38         struct scmi_revision_info *rev = handle->version;
  39
  40         ret = scmi_xfer_get_init(handle, PROTOCOL_ATTRIBUTES,
  41                                  SCMI_PROTOCOL_BASE, 0, sizeof(*attr_info), &t);
  42         if (ret)
  43                 return ret;
  44
  45         ret = scmi_do_xfer(handle, t);
  46         if (!ret) {
  47                 attr_info = t->rx.buf;
  48                 rev->num_protocols = attr_info->num_protocols;
  49                 rev->num_agents = attr_info->num_agents;
  50         }
  51
  52         scmi_xfer_put(handle, t);
  53
  54         return ret;
  55 }
  56
  57 /**
  58  * scmi_base_vendor_id_get() - gets vendor/subvendor identifier ASCII string.
  59  *
  60  * @handle: SCMI entity handle
  61  * @sub_vendor: specify true if sub-vendor ID is needed
  62  *
  63  * Return: 0 on success, else appropriate SCMI error.
  64  */
  65 static int
  66 scmi_base_vendor_id_get(const struct scmi_handle *handle, bool sub_vendor)
  67 {
  68         u8 cmd;
  69         int ret, size;
  70         char *vendor_id;
  71         struct scmi_xfer *t;
  72         struct scmi_revision_info *rev = handle->version;
  73
  74         if (sub_vendor) {
  75                 cmd = BASE_DISCOVER_SUB_VENDOR;
  76                 vendor_id = rev->sub_vendor_id;
  77                 size = ARRAY_SIZE(rev->sub_vendor_id);
  78         } else {
  79                 cmd = BASE_DISCOVER_VENDOR;
  80                 vendor_id = rev->vendor_id;
  81                 size = ARRAY_SIZE(rev->vendor_id);
  82         }
  83
  84         ret = scmi_xfer_get_init(handle, cmd, SCMI_PROTOCOL_BASE, 0, size, &t);
  85         if (ret)
  86                 return ret;
  87
  88         ret = scmi_do_xfer(handle, t);
  89         if (!ret)
  90                 memcpy(vendor_id, t->rx.buf, size);
  91
  92         scmi_xfer_put(handle, t);
  93
  94         return ret;
  95 }
  96
  97 /**
  98  * scmi_base_implementation_version_get() - gets a vendor-specific
  99  *      implementation 32-bit version. The format of the version number is
 100  *      vendor-specific
 101  *
 102  * @handle: SCMI entity handle
 103  *
 104  * Return: 0 on success, else appropriate SCMI error.
 105  */
 106 static int
 107 scmi_base_implementation_version_get(const struct scmi_handle *handle)
 108 {
 109         int ret;
 110         __le32 *impl_ver;
 111         struct scmi_xfer *t;
 112         struct scmi_revision_info *rev = handle->version;
 113
 114         ret = scmi_xfer_get_init(handle, BASE_DISCOVER_IMPLEMENT_VERSION,
 115                                  SCMI_PROTOCOL_BASE, 0, sizeof(*impl_ver), &t);
 116         if (ret)
 117                 return ret;
 118
 119         ret = scmi_do_xfer(handle, t);
 120         if (!ret) {
 121                 impl_ver = t->rx.buf;
 122                 rev->impl_ver = le32_to_cpu(*impl_ver);
 123         }
 124
 125         scmi_xfer_put(handle, t);
 126
 127         return ret;
 128 }
 129
 130 /**
 131  * scmi_base_implementation_list_get() - gets the list of protocols it is
 132  *      OSPM is allowed to access
 133  *
 134  * @handle: SCMI entity handle
 135  * @protocols_imp: pointer to hold the list of protocol identifiers
 136  *
 137  * Return: 0 on success, else appropriate SCMI error.
 138  */
 139 static int scmi_base_implementation_list_get(const struct scmi_handle *handle,
 140                                              u8 *protocols_imp)
 141 {
 142         u8 *list;
 143         int ret, loop;
 144         struct scmi_xfer *t;
 145         __le32 *num_skip, *num_ret;
 146         u32 tot_num_ret = 0, loop_num_ret;
 147         struct device *dev = handle->dev;
 148
 149         ret = scmi_xfer_get_init(handle, BASE_DISCOVER_LIST_PROTOCOLS,
 150                                  SCMI_PROTOCOL_BASE, sizeof(*num_skip), 0, &t);
 151         if (ret)
 152                 return ret;
 153
 154         num_skip = t->tx.buf;
 155         num_ret = t->rx.buf;
 156         list = t->rx.buf + sizeof(*num_ret);
 157
 158         do {
 159                 /* Set the number of protocols to be skipped/already read */
 160                 *num_skip = cpu_to_le32(tot_num_ret);
 161
 162                 ret = scmi_do_xfer(handle, t);
 163                 if (ret)
 164                         break;
 165
 166                 loop_num_ret = le32_to_cpu(*num_ret);
 167                 if (tot_num_ret + loop_num_ret > MAX_PROTOCOLS_IMP) {
 168                         dev_err(dev, "No. of Protocol > MAX_PROTOCOLS_IMP");
 169                         break;
 170                 }
 171
 172                 for (loop = 0; loop < loop_num_ret; loop++)
 173                         protocols_imp[tot_num_ret + loop] = *(list + loop);
 174
 175                 tot_num_ret += loop_num_ret;
 176         } while (loop_num_ret);
 177
 178         scmi_xfer_put(handle, t);
 179
 180         return ret;
 181 }
 182
 183 /**
 184  * scmi_base_discover_agent_get() - discover the name of an agent
 185  *
 186  * @handle: SCMI entity handle
 187  * @id: Agent identifier
 188  * @name: Agent identifier ASCII string
 189  *
 190  * An agent id of 0 is reserved to identify the platform itself.
 191  * Generally operating system is represented as "OSPM"
 192  *
 193  * Return: 0 on success, else appropriate SCMI error.
 194  */
 195 static int scmi_base_discover_agent_get(const struct scmi_handle *handle,
 196                                         int id, char *name)
 197 {
 198         int ret;
 199         struct scmi_xfer *t;
 200
 201         ret = scmi_xfer_get_init(handle, BASE_DISCOVER_AGENT,
 202                                  SCMI_PROTOCOL_BASE, sizeof(__le32),
 203                                  SCMI_MAX_STR_SIZE, &t);
 204         if (ret)
 205                 return ret;
 206
 207         *(__le32 *)t->tx.buf = cpu_to_le32(id);
 208
 209         ret = scmi_do_xfer(handle, t);
 210         if (!ret)
 211                 strlcpy(name, t->rx.buf, SCMI_MAX_STR_SIZE);
 212
 213         scmi_xfer_put(handle, t);
 214
 215         return ret;
 216 }
 217
 218 int scmi_base_protocol_init(struct scmi_handle *h)
 219 {
 220         int id, ret;
 221         u8 *prot_imp;
 222         u32 version;
 223         char name[SCMI_MAX_STR_SIZE];
 224         const struct scmi_handle *handle = h;
 225         struct device *dev = handle->dev;
 226         struct scmi_revision_info *rev = handle->version;
 227
 228         ret = scmi_version_get(handle, SCMI_PROTOCOL_BASE, &version);
 229         if (ret)
 230                 return ret;
 231
 232         prot_imp = devm_kcalloc(dev, MAX_PROTOCOLS_IMP, sizeof(u8), GFP_KERNEL);
 233         if (!prot_imp)
 234                 return -ENOMEM;
 235
 236         rev->major_ver = PROTOCOL_REV_MAJOR(version),
 237         rev->minor_ver = PROTOCOL_REV_MINOR(version);
 238
 239         scmi_base_attributes_get(handle);
 240         scmi_base_vendor_id_get(handle, false);
 241         scmi_base_vendor_id_get(handle, true);
 242         scmi_base_implementation_version_get(handle);
 243         scmi_base_implementation_list_get(handle, prot_imp);
 244         scmi_setup_protocol_implemented(handle, prot_imp);
 245
 246         dev_info(dev, "SCMI Protocol v%d.%d '%s:%s' Firmware version 0x%x\n",
 247                  rev->major_ver, rev->minor_ver, rev->vendor_id,
 248                  rev->sub_vendor_id, rev->impl_ver);
 249         dev_dbg(dev, "Found %d protocol(s) %d agent(s)\n", rev->num_protocols,
 250                 rev->num_agents);
 251
 252         for (id = 0; id < rev->num_agents; id++) {
 253                 scmi_base_discover_agent_get(handle, id, name);
 254                 dev_dbg(dev, "Agent %d: %s\n", id, name);
 255         }
 256
 257         return 0;
 258 }