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 static inline const void *rsc_to_entry_header(const struct rsc_hdr *hdr)
 105 {
 106         u16 offset = le16_to_cpu(hdr->header_offset);
 107
 108         return cmd_db_header->data + offset;
 109 }
 110
 111 static inline void *
 112 rsc_offset(const struct rsc_hdr *hdr, const struct entry_header *ent)
 113 {
 114         u16 offset = le16_to_cpu(hdr->data_offset);
 115         u16 loffset = le16_to_cpu(ent->offset);
 116
 117         return cmd_db_header->data + offset + loffset;
 118 }
 119
 120 /**
 121  * cmd_db_ready - Indicates if command DB is available
 122  *
 123  * Return: 0 on success, errno otherwise
 124  */
 125 int cmd_db_ready(void)
 126 {
 127         if (cmd_db_header == NULL)
 128                 return -EPROBE_DEFER;
 129         else if (!cmd_db_magic_matches(cmd_db_header))
 130                 return -EINVAL;
 131
 132         return 0;
 133 }
 134 EXPORT_SYMBOL(cmd_db_ready);
 135
 136 static int cmd_db_get_header(const char *id, const struct entry_header **eh,
 137                              const struct rsc_hdr **rh)
 138 {
 139         const struct rsc_hdr *rsc_hdr;
 140         const struct entry_header *ent;
 141         int ret, i, j;
 142         u8 query[8];
 143
 144         ret = cmd_db_ready();
 145         if (ret)
 146                 return ret;
 147
 148         /* Pad out query string to same length as in DB */
 149         strncpy(query, id, sizeof(query));
 150
 151         for (i = 0; i < MAX_SLV_ID; i++) {
 152                 rsc_hdr = &cmd_db_header->header[i];
 153                 if (!rsc_hdr->slv_id)
 154                         break;
 155
 156                 ent = rsc_to_entry_header(rsc_hdr);
 157                 for (j = 0; j < le16_to_cpu(rsc_hdr->cnt); j++, ent++) {
 158                         if (memcmp(ent->id, query, sizeof(ent->id)) == 0) {
 159                                 if (eh)
 160                                         *eh = ent;
 161                                 if (rh)
 162                                         *rh = rsc_hdr;
 163                                 return 0;
 164                         }
 165                 }
 166         }
 167
 168         return -ENODEV;
 169 }
 170
 171 /**
 172  * cmd_db_read_addr() - Query command db for resource id address.
 173  *
 174  * @id: resource id to query for address
 175  *
 176  * Return: resource address on success, 0 on error
 177  *
 178  * This is used to retrieve resource address based on resource
 179  * id.
 180  */
 181 u32 cmd_db_read_addr(const char *id)
 182 {
 183         int ret;
 184         const struct entry_header *ent;
 185
 186         ret = cmd_db_get_header(id, &ent, NULL);
 187
 188         return ret < 0 ? 0 : le32_to_cpu(ent->addr);
 189 }
 190 EXPORT_SYMBOL(cmd_db_read_addr);
 191
 192 /**
 193  * cmd_db_read_aux_data() - Query command db for aux data.
 194  *
 195  *  @id: Resource to retrieve AUX Data on
 196  *  @len: size of data buffer returned
 197  *
 198  *  Return: pointer to data on success, error pointer otherwise
 199  */
 200 const void *cmd_db_read_aux_data(const char *id, size_t *len)
 201 {
 202         int ret;
 203         const struct entry_header *ent;
 204         const struct rsc_hdr *rsc_hdr;
 205
 206         ret = cmd_db_get_header(id, &ent, &rsc_hdr);
 207         if (ret)
 208                 return ERR_PTR(ret);
 209
 210         if (len)
 211                 *len = le16_to_cpu(ent->len);
 212
 213         return rsc_offset(rsc_hdr, ent);
 214 }
 215 EXPORT_SYMBOL(cmd_db_read_aux_data);
 216
 217 /**
 218  * cmd_db_read_slave_id - Get the slave ID for a given resource address
 219  *
 220  * @id: Resource id to query the DB for version
 221  *
 222  * Return: cmd_db_hw_type enum on success, CMD_DB_HW_INVALID on error
 223  */
 224 enum cmd_db_hw_type cmd_db_read_slave_id(const char *id)
 225 {
 226         int ret;
 227         const struct entry_header *ent;
 228         u32 addr;
 229
 230         ret = cmd_db_get_header(id, &ent, NULL);
 231         if (ret < 0)
 232                 return CMD_DB_HW_INVALID;
 233
 234         addr = le32_to_cpu(ent->addr);
 235         return (addr >> SLAVE_ID_SHIFT) & SLAVE_ID_MASK;
 236 }
 237 EXPORT_SYMBOL(cmd_db_read_slave_id);
 238
 239 static int cmd_db_dev_probe(struct platform_device *pdev)
 240 {
 241         struct reserved_mem *rmem;
 242         int ret = 0;
 243
 244         rmem = of_reserved_mem_lookup(pdev->dev.of_node);
 245         if (!rmem) {
 246                 dev_err(&pdev->dev, "failed to acquire memory region\n");
 247                 return -EINVAL;
 248         }
 249
 250         cmd_db_header = memremap(rmem->base, rmem->size, MEMREMAP_WB);
 251         if (IS_ERR_OR_NULL(cmd_db_header)) {
 252                 ret = PTR_ERR(cmd_db_header);
 253                 cmd_db_header = NULL;
 254                 return ret;
 255         }
 256
 257         if (!cmd_db_magic_matches(cmd_db_header)) {
 258                 dev_err(&pdev->dev, "Invalid Command DB Magic\n");
 259                 return -EINVAL;
 260         }
 261
 262         return 0;
 263 }
 264
 265 static const struct of_device_id cmd_db_match_table[] = {
 266         { .compatible = "qcom,cmd-db" },
 267         { },
 268 };
 269
 270 static struct platform_driver cmd_db_dev_driver = {
 271         .probe  = cmd_db_dev_probe,
 272         .driver = {
 273                    .name = "cmd-db",
 274                    .of_match_table = cmd_db_match_table,
 275         },
 276 };
 277
 278 static int __init cmd_db_device_init(void)
 279 {
 280         return platform_driver_register(&cmd_db_dev_driver);
 281 }
 282 arch_initcall(cmd_db_device_init);