1/* SPDX-License-Identifier: GPL-2.0 */
2/* Copyright (c) 2016-2018, 2020, The Linux Foundation. All rights reserved. */
3
4#include <linux/debugfs.h>
5#include <linux/kernel.h>
6#include <linux/module.h>
7#include <linux/of.h>
8#include <linux/of_address.h>
9#include <linux/of_reserved_mem.h>
10#include <linux/platform_device.h>
11#include <linux/seq_file.h>
12#include <linux/types.h>
13
14#include <soc/qcom/cmd-db.h>
15
16#define NUM_PRIORITY		2
17#define MAX_SLV_ID		8
18#define SLAVE_ID_MASK		0x7
19#define SLAVE_ID_SHIFT		16
20
21/**
22 * struct entry_header: header for each entry in cmddb
23 *
24 * @id: resource's identifier
25 * @priority: unused
26 * @addr: the address of the resource
27 * @len: length of the data
28 * @offset: offset from :@data_offset, start of the data
29 */
30struct entry_header {
31	u8 id[8];
32	__le32 priority[NUM_PRIORITY];
33	__le32 addr;
34	__le16 len;
35	__le16 offset;
36};
37
38/**
39 * struct rsc_hdr: resource header information
40 *
41 * @slv_id: id for the resource
42 * @header_offset: entry's header at offset from the end of the cmd_db_header
43 * @data_offset: entry's data at offset from the end of the cmd_db_header
44 * @cnt: number of entries for HW type
45 * @version: MSB is major, LSB is minor
46 * @reserved: reserved for future use.
47 */
48struct rsc_hdr {
49	__le16 slv_id;
50	__le16 header_offset;
51	__le16 data_offset;
52	__le16 cnt;
53	__le16 version;
54	__le16 reserved[3];
55};
56
57/**
58 * struct cmd_db_header: The DB header information
59 *
60 * @version: The cmd db version
61 * @magic: constant expected in the database
62 * @header: array of resources
63 * @checksum: checksum for the header. Unused.
64 * @reserved: reserved memory
65 * @data: driver specific data
66 */
67struct cmd_db_header {
68	__le32 version;
69	u8 magic[4];
70	struct rsc_hdr header[MAX_SLV_ID];
71	__le32 checksum;
72	__le32 reserved;
73	u8 data[];
74};
75
76/**
77 * DOC: Description of the Command DB database.
78 *
79 * At the start of the command DB memory is the cmd_db_header structure.
80 * The cmd_db_header holds the version, checksum, magic key as well as an
81 * array for header for each slave (depicted by the rsc_header). Each h/w
82 * based accelerator is a 'slave' (shared resource) and has slave id indicating
83 * the type of accelerator. The rsc_header is the header for such individual
84 * slaves of a given type. The entries for each of these slaves begin at the
85 * rsc_hdr.header_offset. In addition each slave could have auxiliary data
86 * that may be needed by the driver. The data for the slave starts at the
87 * entry_header.offset to the location pointed to by the rsc_hdr.data_offset.
88 *
89 * Drivers have a stringified key to a slave/resource. They can query the slave
90 * information and get the slave id and the auxiliary data and the length of the
91 * data. Using this information, they can format the request to be sent to the
92 * h/w accelerator and request a resource state.
93 */
94
95static const u8 CMD_DB_MAGIC[] = { 0xdb, 0x30, 0x03, 0x0c };
96
97static bool cmd_db_magic_matches(const struct cmd_db_header *header)
98{
99	const u8 *magic = header->magic;
100
101	return memcmp(magic, CMD_DB_MAGIC, ARRAY_SIZE(CMD_DB_MAGIC)) == 0;
102}
103
104static struct cmd_db_header *cmd_db_header;
105
106static inline const void *rsc_to_entry_header(const struct rsc_hdr *hdr)
107{
108	u16 offset = le16_to_cpu(hdr->header_offset);
109
110	return cmd_db_header->data + offset;
111}
112
113static inline void *
114rsc_offset(const struct rsc_hdr *hdr, const struct entry_header *ent)
115{
116	u16 offset = le16_to_cpu(hdr->data_offset);
117	u16 loffset = le16_to_cpu(ent->offset);
118
119	return cmd_db_header->data + offset + loffset;
120}
121
122/**
123 * cmd_db_ready - Indicates if command DB is available
124 *
125 * Return: 0 on success, errno otherwise
126 */
127int cmd_db_ready(void)
128{
129	if (cmd_db_header == NULL)
130		return -EPROBE_DEFER;
131	else if (!cmd_db_magic_matches(cmd_db_header))
132		return -EINVAL;
133
134	return 0;
135}
136EXPORT_SYMBOL_GPL(cmd_db_ready);
137
138static int cmd_db_get_header(const char *id, const struct entry_header **eh,
139			     const struct rsc_hdr **rh)
140{
141	const struct rsc_hdr *rsc_hdr;
142	const struct entry_header *ent;
143	int ret, i, j;
144	u8 query[sizeof(ent->id)] __nonstring;
145
146	ret = cmd_db_ready();
147	if (ret)
148		return ret;
149
150	/*
151	 * Pad out query string to same length as in DB. NOTE: the output
152	 * query string is not necessarily '\0' terminated if it bumps up
153	 * against the max size. That's OK and expected.
154	 */
155	strncpy(query, id, sizeof(query));
156
157	for (i = 0; i < MAX_SLV_ID; i++) {
158		rsc_hdr = &cmd_db_header->header[i];
159		if (!rsc_hdr->slv_id)
160			break;
161
162		ent = rsc_to_entry_header(rsc_hdr);
163		for (j = 0; j < le16_to_cpu(rsc_hdr->cnt); j++, ent++) {
164			if (memcmp(ent->id, query, sizeof(ent->id)) == 0) {
165				if (eh)
166					*eh = ent;
167				if (rh)
168					*rh = rsc_hdr;
169				return 0;
170			}
171		}
172	}
173
174	return -ENODEV;
175}
176
177/**
178 * cmd_db_read_addr() - Query command db for resource id address.
179 *
180 * @id: resource id to query for address
181 *
182 * Return: resource address on success, 0 on error
183 *
184 * This is used to retrieve resource address based on resource
185 * id.
186 */
187u32 cmd_db_read_addr(const char *id)
188{
189	int ret;
190	const struct entry_header *ent;
191
192	ret = cmd_db_get_header(id, &ent, NULL);
193
194	return ret < 0 ? 0 : le32_to_cpu(ent->addr);
195}
196EXPORT_SYMBOL_GPL(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 *  @len: size of data buffer returned
203 *
204 *  Return: pointer to data on success, error pointer otherwise
205 */
206const void *cmd_db_read_aux_data(const char *id, size_t *len)
207{
208	int ret;
209	const struct entry_header *ent;
210	const struct rsc_hdr *rsc_hdr;
211
212	ret = cmd_db_get_header(id, &ent, &rsc_hdr);
213	if (ret)
214		return ERR_PTR(ret);
215
216	if (len)
217		*len = le16_to_cpu(ent->len);
218
219	return rsc_offset(rsc_hdr, ent);
220}
221EXPORT_SYMBOL_GPL(cmd_db_read_aux_data);
222
223/**
224 * cmd_db_read_slave_id - Get the slave ID for a given resource address
225 *
226 * @id: Resource id to query the DB for version
227 *
228 * Return: cmd_db_hw_type enum on success, CMD_DB_HW_INVALID on error
229 */
230enum cmd_db_hw_type cmd_db_read_slave_id(const char *id)
231{
232	int ret;
233	const struct entry_header *ent;
234	u32 addr;
235
236	ret = cmd_db_get_header(id, &ent, NULL);
237	if (ret < 0)
238		return CMD_DB_HW_INVALID;
239
240	addr = le32_to_cpu(ent->addr);
241	return (addr >> SLAVE_ID_SHIFT) & SLAVE_ID_MASK;
242}
243EXPORT_SYMBOL_GPL(cmd_db_read_slave_id);
244
245#ifdef CONFIG_DEBUG_FS
246static int cmd_db_debugfs_dump(struct seq_file *seq, void *p)
247{
248	int i, j;
249	const struct rsc_hdr *rsc;
250	const struct entry_header *ent;
251	const char *name;
252	u16 len, version;
253	u8 major, minor;
254
255	seq_puts(seq, "Command DB DUMP\n");
256
257	for (i = 0; i < MAX_SLV_ID; i++) {
258		rsc = &cmd_db_header->header[i];
259		if (!rsc->slv_id)
260			break;
261
262		switch (le16_to_cpu(rsc->slv_id)) {
263		case CMD_DB_HW_ARC:
264			name = "ARC";
265			break;
266		case CMD_DB_HW_VRM:
267			name = "VRM";
268			break;
269		case CMD_DB_HW_BCM:
270			name = "BCM";
271			break;
272		default:
273			name = "Unknown";
274			break;
275		}
276
277		version = le16_to_cpu(rsc->version);
278		major = version >> 8;
279		minor = version;
280
281		seq_printf(seq, "Slave %s (v%u.%u)\n", name, major, minor);
282		seq_puts(seq, "-------------------------\n");
283
284		ent = rsc_to_entry_header(rsc);
285		for (j = 0; j < le16_to_cpu(rsc->cnt); j++, ent++) {
286			seq_printf(seq, "0x%05x: %*pEp", le32_to_cpu(ent->addr),
287				   (int)strnlen(ent->id, sizeof(ent->id)), ent->id);
288
289			len = le16_to_cpu(ent->len);
290			if (len) {
291				seq_printf(seq, " [%*ph]",
292					   len, rsc_offset(rsc, ent));
293			}
294			seq_putc(seq, '\n');
295		}
296	}
297
298	return 0;
299}
300
301static int open_cmd_db_debugfs(struct inode *inode, struct file *file)
302{
303	return single_open(file, cmd_db_debugfs_dump, inode->i_private);
304}
305#endif
306
307static const struct file_operations cmd_db_debugfs_ops = {
308#ifdef CONFIG_DEBUG_FS
309	.open = open_cmd_db_debugfs,
310#endif
311	.read = seq_read,
312	.llseek = seq_lseek,
313	.release = single_release,
314};
315
316static int cmd_db_dev_probe(struct platform_device *pdev)
317{
318	struct reserved_mem *rmem;
319	int ret = 0;
320
321	rmem = of_reserved_mem_lookup(pdev->dev.of_node);
322	if (!rmem) {
323		dev_err(&pdev->dev, "failed to acquire memory region\n");
324		return -EINVAL;
325	}
326
327	cmd_db_header = memremap(rmem->base, rmem->size, MEMREMAP_WB);
328	if (!cmd_db_header) {
329		ret = -ENOMEM;
330		cmd_db_header = NULL;
331		return ret;
332	}
333
334	if (!cmd_db_magic_matches(cmd_db_header)) {
335		dev_err(&pdev->dev, "Invalid Command DB Magic\n");
336		return -EINVAL;
337	}
338
339	debugfs_create_file("cmd-db", 0400, NULL, NULL, &cmd_db_debugfs_ops);
340
341	device_set_pm_not_required(&pdev->dev);
342
343	return 0;
344}
345
346static const struct of_device_id cmd_db_match_table[] = {
347	{ .compatible = "qcom,cmd-db" },
348	{ }
349};
350MODULE_DEVICE_TABLE(of, cmd_db_match_table);
351
352static struct platform_driver cmd_db_dev_driver = {
353	.probe  = cmd_db_dev_probe,
354	.driver = {
355		   .name = "cmd-db",
356		   .of_match_table = cmd_db_match_table,
357		   .suppress_bind_attrs = true,
358	},
359};
360
361static int __init cmd_db_device_init(void)
362{
363	return platform_driver_register(&cmd_db_dev_driver);
364}
365arch_initcall(cmd_db_device_init);
366
367MODULE_DESCRIPTION("Qualcomm Technologies, Inc. Command DB Driver");
368MODULE_LICENSE("GPL v2");
369