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); 283