drivers/soc/qcom/cmd-db.c

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /* Copyright (c) 2016-2018, The Linux Foundation. All rights reserved. */
   3
   4 #include <linux/kernel.h>
   5 #include <linux/of.h>
   6 #include <linux/of_address.h>
   7 #include <linux/of_platform.h>
   8 #include <linux/of_reserved_mem.h>
   9 #include <linux/platform_device.h>
  10 #include <linux/types.h>
  11
  12 #include <soc/qcom/cmd-db.h>
  13
  14 #define NUM_PRIORITY            2
  15 #define MAX_SLV_ID              8
  16 #define SLAVE_ID_MASK           0x7
  17 #define SLAVE_ID_SHIFT          16
  18
  19 /**
  20  * struct entry_header: header for each entry in cmddb
  21  *
  22  * @id: resource's identifier
  23  * @priority: unused
  24  * @addr: the address of the resource
  25  * @len: length of the data
  26  * @offset: offset from :@data_offset, start of the data
  27  */
  28 struct entry_header {
  29         u8 id[8];
  30         __le32 priority[NUM_PRIORITY];
  31         __le32 addr;
  32         __le16 len;
  33         __le16 offset;
  34 };
  35
  36 /**
  37  * struct rsc_hdr: resource header information
  38  *
  39  * @slv_id: id for the resource
  40  * @header_offset: entry's header at offset from the end of the cmd_db_header
  41  * @data_offset: entry's data at offset from the end of the cmd_db_header
  42  * @cnt: number of entries for HW type
  43  * @version: MSB is major, LSB is minor
  44  * @reserved: reserved for future use.
  45  */
  46 struct rsc_hdr {
  47         __le16 slv_id;
  48         __le16 header_offset;
  49         __le16 data_offset;
  50         __le16 cnt;
  51         __le16 version;
  52         __le16 reserved[3];
  53 };
  54
  55 /**
  56  * struct cmd_db_header: The DB header information
  57  *
  58  * @version: The cmd db version
  59  * @magic: constant expected in the database
  60  * @header: array of resources
  61  * @checksum: checksum for the header. Unused.
  62  * @reserved: reserved memory
  63  * @data: driver specific data
  64  */
  65 struct cmd_db_header {
  66         __le32 version;
  67         u8 magic[4];
  68         struct rsc_hdr header[MAX_SLV_ID];
  69         __le32 checksum;
  70         __le32 reserved;
  71         u8 data[];
  72 };
  73
  74 /**
  75  * DOC: Description of the Command DB database.
  76  *
  77  * At the start of the command DB memory is the cmd_db_header structure.
  78  * The cmd_db_header holds the version, checksum, magic key as well as an
  79  * array for header for each slave (depicted by the rsc_header). Each h/w
  80  * based accelerator is a 'slave' (shared resource) and has slave id indicating
  81  * the type of accelerator. The rsc_header is the header for such individual
  82  * slaves of a given type. The entries for each of these slaves begin at the
  83  * rsc_hdr.header_offset. In addition each slave could have auxiliary data
  84  * that may be needed by the driver. The data for the slave starts at the
  85  * entry_header.offset to the location pointed to by the rsc_hdr.data_offset.
  86  *
  87  * Drivers have a stringified key to a slave/resource. They can query the slave
  88  * information and get the slave id and the auxiliary data and the length of the
  89  * data. Using this information, they can format the request to be sent to the
  90  * h/w accelerator and request a resource state.
  91  */
  92
  93 static const u8 CMD_DB_MAGIC[] = { 0xdb, 0x30, 0x03, 0x0c };
  94
  95 static bool cmd_db_magic_matches(const struct cmd_db_header *header)
  96 {
  97         const u8 *magic = header->magic;
  98
  99         return memcmp(magic, CMD_DB_MAGIC, ARRAY_SIZE(CMD_DB_MAGIC)) == 0;
 100 }
 101
 102 static struct cmd_db_header *cmd_db_header;
 103
 104
 105 static inline void *rsc_to_entry_header(struct rsc_hdr *hdr)
 106 {
 107         u16 offset = le16_to_cpu(hdr->header_offset);
 108
 109         return cmd_db_header->data + offset;
 110 }
 111
 112 static inline void *
 113 rsc_offset(struct rsc_hdr *hdr, struct entry_header *ent)
 114 {
 115         u16 offset = le16_to_cpu(hdr->data_offset);
 116         u16 loffset = le16_to_cpu(ent->offset);
 117
 118         return cmd_db_header->data + offset + loffset;
 119 }
 120
 121 /**
 122  * cmd_db_ready - Indicates if command DB is available
 123  *
 124  * Return: 0 on success, errno otherwise
 125  */
 126 int cmd_db_ready(void)
 127 {
 128         if (cmd_db_header == NULL)
 129                 return -EPROBE_DEFER;
 130         else if (!cmd_db_magic_matches(cmd_db_header))
 131                 return -EINVAL;
 132
 133         return 0;
 134 }
 135 EXPORT_SYMBOL(cmd_db_ready);
 136
 137 static int cmd_db_get_header(const char *id, struct entry_header *eh,
 138                              struct rsc_hdr *rh)
 139 {
 140         struct rsc_hdr *rsc_hdr;
 141         struct entry_header *ent;
 142         int ret, i, j;
 143         u8 query[8];
 144
 145         ret = cmd_db_ready();
 146         if (ret)
 147                 return ret;
 148
 149         if (!eh || !rh)
 150                 return -EINVAL;
 151
 152         /* Pad out query string to same length as in DB */
 153         strncpy(query, id, sizeof(query));
 154
 155         for (i = 0; i < MAX_SLV_ID; i++) {
 156                 rsc_hdr = &cmd_db_header->header[i];
 157                 if (!rsc_hdr->slv_id)
 158                         break;
 159
 160                 ent = rsc_to_entry_header(rsc_hdr);
 161                 for (j = 0; j < le16_to_cpu(rsc_hdr->cnt); j++, ent++) {
 162                         if (memcmp(ent->id, query, sizeof(ent->id)) == 0)
 163                                 break;
 164                 }
 165
 166                 if (j < le16_to_cpu(rsc_hdr->cnt)) {
 167                         memcpy(eh, ent, sizeof(*ent));
 168                         memcpy(rh, rsc_hdr, sizeof(*rh));
 169                         return 0;
 170                 }
 171         }
 172
 173         return -ENODEV;
 174 }
 175
 176 /**
 177  * cmd_db_read_addr() - Query command db for resource id address.
 178  *
 179  * @id: resource id to query for address
 180  *
 181  * Return: resource address on success, 0 on error
 182  *
 183  * This is used to retrieve resource address based on resource
 184  * id.
 185  */
 186 u32 cmd_db_read_addr(const char *id)
 187 {
 188         int ret;
 189         struct entry_header ent;
 190         struct rsc_hdr rsc_hdr;
 191
 192         ret = cmd_db_get_header(id, &ent, &rsc_hdr);
 193
 194         return ret < 0 ? 0 : le32_to_cpu(ent.addr);
 195 }
 196 EXPORT_SYMBOL(cmd_db_read_addr);
 197
 198 /**
 199  * cmd_db_read_aux_data() - Query command db for aux data.
 200  *
 201  *  @id: Resource to retrieve AUX Data on.
 202  *  @data: Data buffer to copy returned aux data to. Returns size on NULL
 203  *  @len: Caller provides size of data buffer passed in.
 204  *
 205  *  Return: size of data on success, errno otherwise
 206  */
 207 int cmd_db_read_aux_data(const char *id, u8 *data, size_t len)
 208 {
 209         int ret;
 210         struct entry_header ent;
 211         struct rsc_hdr rsc_hdr;
 212         u16 ent_len;
 213
 214         if (!data)
 215                 return -EINVAL;
 216
 217         ret = cmd_db_get_header(id, &ent, &rsc_hdr);
 218         if (ret)
 219                 return ret;
 220
 221         ent_len = le16_to_cpu(ent.len);
 222         if (len < ent_len)
 223                 return -EINVAL;
 224
 225         len = min_t(u16, ent_len, len);
 226         memcpy(data, rsc_offset(&rsc_hdr, &ent), len);
 227
 228         return len;
 229 }
 230 EXPORT_SYMBOL(cmd_db_read_aux_data);
 231
 232 /**
 233  * cmd_db_read_aux_data_len - Get the length of the auxiliary data stored in DB.
 234  *
 235  * @id: Resource to retrieve AUX Data.
 236  *
 237  * Return: size on success, 0 on error
 238  */
 239 size_t cmd_db_read_aux_data_len(const char *id)
 240 {
 241         int ret;
 242         struct entry_header ent;
 243         struct rsc_hdr rsc_hdr;
 244
 245         ret = cmd_db_get_header(id, &ent, &rsc_hdr);
 246
 247         return ret < 0 ? 0 : le16_to_cpu(ent.len);
 248 }
 249 EXPORT_SYMBOL(cmd_db_read_aux_data_len);
 250
 251 /**
 252  * cmd_db_read_slave_id - Get the slave ID for a given resource address
 253  *
 254  * @id: Resource id to query the DB for version
 255  *
 256  * Return: cmd_db_hw_type enum on success, CMD_DB_HW_INVALID on error
 257  */
 258 enum cmd_db_hw_type cmd_db_read_slave_id(const char *id)
 259 {
 260         int ret;
 261         struct entry_header ent;
 262         struct rsc_hdr rsc_hdr;
 263         u32 addr;
 264
 265         ret = cmd_db_get_header(id, &ent, &rsc_hdr);
 266         if (ret < 0)
 267                 return CMD_DB_HW_INVALID;
 268
 269         addr = le32_to_cpu(ent.addr);
 270         return (addr >> SLAVE_ID_SHIFT) & SLAVE_ID_MASK;
 271 }
 272 EXPORT_SYMBOL(cmd_db_read_slave_id);
 273
 274 static int cmd_db_dev_probe(struct platform_device *pdev)
 275 {
 276         struct reserved_mem *rmem;
 277         int ret = 0;
 278
 279         rmem = of_reserved_mem_lookup(pdev->dev.of_node);
 280         if (!rmem) {
 281                 dev_err(&pdev->dev, "failed to acquire memory region\n");
 282                 return -EINVAL;
 283         }
 284
 285         cmd_db_header = memremap(rmem->base, rmem->size, MEMREMAP_WB);
 286         if (IS_ERR_OR_NULL(cmd_db_header)) {
 287                 ret = PTR_ERR(cmd_db_header);
 288                 cmd_db_header = NULL;
 289                 return ret;
 290         }
 291
 292         if (!cmd_db_magic_matches(cmd_db_header)) {
 293                 dev_err(&pdev->dev, "Invalid Command DB Magic\n");
 294                 return -EINVAL;
 295         }
 296
 297         return 0;
 298 }
 299
 300 static const struct of_device_id cmd_db_match_table[] = {
 301         { .compatible = "qcom,cmd-db" },
 302         { },
 303 };
 304
 305 static struct platform_driver cmd_db_dev_driver = {
 306         .probe  = cmd_db_dev_probe,
 307         .driver = {
 308                    .name = "cmd-db",
 309                    .of_match_table = cmd_db_match_table,
 310         },
 311 };
 312
 313 static int __init cmd_db_device_init(void)
 314 {
 315         return platform_driver_register(&cmd_db_dev_driver);
 316 }
 317 arch_initcall(cmd_db_device_init);