1 files changed, 317 insertions, 0 deletions
diff --git a/drivers/soc/qcom/cmd-db.c b/drivers/soc/qcom/cmd-db.c
new file mode 100644
index 000000000000..a6f646295f06
--- /dev/null
+++ b/drivers/soc/qcom/cmd-db.c
@@ -0,0 +1,317 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (c) 2016-2018, The Linux Foundation. All rights reserved. */
+
+#include <linux/kernel.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
+#include <linux/of_reserved_mem.h>
+#include <linux/platform_device.h>
+#include <linux/types.h>
+
+#include <soc/qcom/cmd-db.h>
+
+#define NUM_PRIORITY		2
+#define MAX_SLV_ID		8
+#define SLAVE_ID_MASK		0x7
+#define SLAVE_ID_SHIFT		16
+
+/**
+ * struct entry_header: header for each entry in cmddb
+ *
+ * @id: resource's identifier
+ * @priority: unused
+ * @addr: the address of the resource
+ * @len: length of the data
+ * @offset: offset from :@data_offset, start of the data
+ */
+struct entry_header {
+	u8 id[8];
+	__le32 priority[NUM_PRIORITY];
+	__le32 addr;
+	__le16 len;
+	__le16 offset;
+};
+
+/**
+ * struct rsc_hdr: resource header information
+ *
+ * @slv_id: id for the resource
+ * @header_offset: entry's header at offset from the end of the cmd_db_header
+ * @data_offset: entry's data at offset from the end of the cmd_db_header
+ * @cnt: number of entries for HW type
+ * @version: MSB is major, LSB is minor
+ * @reserved: reserved for future use.
+ */
+struct rsc_hdr {
+	__le16 slv_id;
+	__le16 header_offset;
+	__le16 data_offset;
+	__le16 cnt;
+	__le16 version;
+	__le16 reserved[3];
+};
+
+/**
+ * struct cmd_db_header: The DB header information
+ *
+ * @version: The cmd db version
+ * @magic: constant expected in the database
+ * @header: array of resources
+ * @checksum: checksum for the header. Unused.
+ * @reserved: reserved memory
+ * @data: driver specific data
+ */
+struct cmd_db_header {
+	__le32 version;
+	u8 magic[4];
+	struct rsc_hdr header[MAX_SLV_ID];
+	__le32 checksum;
+	__le32 reserved;
+	u8 data[];
+};
+
+/**
+ * DOC: Description of the Command DB database.
+ *
+ * At the start of the command DB memory is the cmd_db_header structure.
+ * The cmd_db_header holds the version, checksum, magic key as well as an
+ * array for header for each slave (depicted by the rsc_header). Each h/w
+ * based accelerator is a 'slave' (shared resource) and has slave id indicating
+ * the type of accelerator. The rsc_header is the header for such individual
+ * slaves of a given type. The entries for each of these slaves begin at the
+ * rsc_hdr.header_offset. In addition each slave could have auxiliary data
+ * that may be needed by the driver. The data for the slave starts at the
+ * entry_header.offset to the location pointed to by the rsc_hdr.data_offset.
+ *
+ * Drivers have a stringified key to a slave/resource. They can query the slave
+ * information and get the slave id and the auxiliary data and the length of the
+ * data. Using this information, they can format the request to be sent to the
+ * h/w accelerator and request a resource state.
+ */
+
+static const u8 CMD_DB_MAGIC[] = { 0xdb, 0x30, 0x03, 0x0c };
+
+static bool cmd_db_magic_matches(const struct cmd_db_header *header)
+{
+	const u8 *magic = header->magic;
+
+	return memcmp(magic, CMD_DB_MAGIC, ARRAY_SIZE(CMD_DB_MAGIC)) == 0;
+}
+
+static struct cmd_db_header *cmd_db_header;
+
+
+static inline void *rsc_to_entry_header(struct rsc_hdr *hdr)
+{
+	u16 offset = le16_to_cpu(hdr->header_offset);
+
+	return cmd_db_header->data + offset;
+}
+
+static inline void *
+rsc_offset(struct rsc_hdr *hdr, struct entry_header *ent)
+{
+	u16 offset = le16_to_cpu(hdr->data_offset);
+	u16 loffset = le16_to_cpu(ent->offset);
+
+	return cmd_db_header->data + offset + loffset;
+}
+
+/**
+ * cmd_db_ready - Indicates if command DB is available
+ *
+ * Return: 0 on success, errno otherwise
+ */
+int cmd_db_ready(void)
+{
+	if (cmd_db_header == NULL)
+		return -EPROBE_DEFER;
+	else if (!cmd_db_magic_matches(cmd_db_header))
+		return -EINVAL;
+
+	return 0;
+}
+EXPORT_SYMBOL(cmd_db_ready);
+
+static int cmd_db_get_header(const char *id, struct entry_header *eh,
+			     struct rsc_hdr *rh)
+{
+	struct rsc_hdr *rsc_hdr;
+	struct entry_header *ent;
+	int ret, i, j;
+	u8 query[8];
+
+	ret = cmd_db_ready();
+	if (ret)
+		return ret;
+
+	if (!eh || !rh)
+		return -EINVAL;
+
+	/* Pad out query string to same length as in DB */
+	strncpy(query, id, sizeof(query));
+
+	for (i = 0; i < MAX_SLV_ID; i++) {
+		rsc_hdr = &cmd_db_header->header[i];
+		if (!rsc_hdr->slv_id)
+			break;
+
+		ent = rsc_to_entry_header(rsc_hdr);
+		for (j = 0; j < le16_to_cpu(rsc_hdr->cnt); j++, ent++) {
+			if (memcmp(ent->id, query, sizeof(ent->id)) == 0)
+				break;
+		}
+
+		if (j < le16_to_cpu(rsc_hdr->cnt)) {
+			memcpy(eh, ent, sizeof(*ent));
+			memcpy(rh, rsc_hdr, sizeof(*rh));
+			return 0;
+		}
+	}
+
+	return -ENODEV;
+}
+
+/**
+ * cmd_db_read_addr() - Query command db for resource id address.
+ *
+ * @id: resource id to query for address
+ *
+ * Return: resource address on success, 0 on error
+ *
+ * This is used to retrieve resource address based on resource
+ * id.
+ */
+u32 cmd_db_read_addr(const char *id)
+{
+	int ret;
+	struct entry_header ent;
+	struct rsc_hdr rsc_hdr;
+
+	ret = cmd_db_get_header(id, &ent, &rsc_hdr);
+
+	return ret < 0 ? 0 : le32_to_cpu(ent.addr);
+}
+EXPORT_SYMBOL(cmd_db_read_addr);
+
+/**
+ * cmd_db_read_aux_data() - Query command db for aux data.
+ *
+ *  @id: Resource to retrieve AUX Data on.
+ *  @data: Data buffer to copy returned aux data to. Returns size on NULL
+ *  @len: Caller provides size of data buffer passed in.
+ *
+ *  Return: size of data on success, errno otherwise
+ */
+int cmd_db_read_aux_data(const char *id, u8 *data, size_t len)
+{
+	int ret;
+	struct entry_header ent;
+	struct rsc_hdr rsc_hdr;
+	u16 ent_len;
+
+	if (!data)
+		return -EINVAL;
+
+	ret = cmd_db_get_header(id, &ent, &rsc_hdr);
+	if (ret)
+		return ret;
+
+	ent_len = le16_to_cpu(ent.len);
+	if (len < ent_len)
+		return -EINVAL;
+
+	len = min_t(u16, ent_len, len);
+	memcpy(data, rsc_offset(&rsc_hdr, &ent), len);
+
+	return len;
+}
+EXPORT_SYMBOL(cmd_db_read_aux_data);
+
+/**
+ * cmd_db_read_aux_data_len - Get the length of the auxiliary data stored in DB.
+ *
+ * @id: Resource to retrieve AUX Data.
+ *
+ * Return: size on success, 0 on error
+ */
+size_t cmd_db_read_aux_data_len(const char *id)
+{
+	int ret;
+	struct entry_header ent;
+	struct rsc_hdr rsc_hdr;
+
+	ret = cmd_db_get_header(id, &ent, &rsc_hdr);
+
+	return ret < 0 ? 0 : le16_to_cpu(ent.len);
+}
+EXPORT_SYMBOL(cmd_db_read_aux_data_len);
+
+/**
+ * cmd_db_read_slave_id - Get the slave ID for a given resource address
+ *
+ * @id: Resource id to query the DB for version
+ *
+ * Return: cmd_db_hw_type enum on success, CMD_DB_HW_INVALID on error
+ */
+enum cmd_db_hw_type cmd_db_read_slave_id(const char *id)
+{
+	int ret;
+	struct entry_header ent;
+	struct rsc_hdr rsc_hdr;
+	u32 addr;
+
+	ret = cmd_db_get_header(id, &ent, &rsc_hdr);
+	if (ret < 0)
+		return CMD_DB_HW_INVALID;
+
+	addr = le32_to_cpu(ent.addr);
+	return (addr >> SLAVE_ID_SHIFT) & SLAVE_ID_MASK;
+}
+EXPORT_SYMBOL(cmd_db_read_slave_id);
+
+static int cmd_db_dev_probe(struct platform_device *pdev)
+{
+	struct reserved_mem *rmem;
+	int ret = 0;
+
+	rmem = of_reserved_mem_lookup(pdev->dev.of_node);
+	if (!rmem) {
+		dev_err(&pdev->dev, "failed to acquire memory region\n");
+		return -EINVAL;
+	}
+
+	cmd_db_header = memremap(rmem->base, rmem->size, MEMREMAP_WB);
+	if (IS_ERR_OR_NULL(cmd_db_header)) {
+		ret = PTR_ERR(cmd_db_header);
+		cmd_db_header = NULL;
+		return ret;
+	}
+
+	if (!cmd_db_magic_matches(cmd_db_header)) {
+		dev_err(&pdev->dev, "Invalid Command DB Magic\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static const struct of_device_id cmd_db_match_table[] = {
+	{ .compatible = "qcom,cmd-db" },
+	{ },
+};
+
+static struct platform_driver cmd_db_dev_driver = {
+	.probe  = cmd_db_dev_probe,
+	.driver = {
+		   .name = "cmd-db",
+		   .of_match_table = cmd_db_match_table,
+	},
+};
+
+static int __init cmd_db_device_init(void)
+{
+	return platform_driver_register(&cmd_db_dev_driver);
+}
+arch_initcall(cmd_db_device_init);