greybus: firmware: Add firmware-download protocol driver

This patch adds Firmware Download Protocol support to firmware core,
which allows an Interface to download a firmware package over Unipro.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Jun Li <li_jun@projectara.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

drivers/staging/greybus/Makefile

@@ -39,7 +39,7 @@ gb-audio-apbridgea-y := audio_apbridgea.o
 gb-audio-manager-y += audio_manager.o
 gb-audio-manager-y += audio_manager_module.o
 gb-camera-y := camera.o
-gb-firmware-y := fw-core.o
+gb-firmware-y := fw-core.o fw-download.o
 
 obj-m += greybus.o
 obj-m += gb-phy.o

drivers/staging/greybus/firmware.h

@@ -0,0 +1,20 @@
+/*
+ * Greybus Firmware Management Header
+ *
+ * Copyright 2016 Google Inc.
+ * Copyright 2016 Linaro Ltd.
+ *
+ * Released under the GPLv2 only.
+ */
+
+#ifndef __FIRMWARE_H
+#define __FIRMWARE_H
+
+#include "greybus.h"
+
+/* Firmware Download Protocol specific functions */
+int gb_fw_download_request_handler(struct gb_operation *op);
+int gb_fw_download_connection_init(struct gb_connection *connection);
+void gb_fw_download_connection_exit(struct gb_connection *connection);
+
+#endif /* __FIRMWARE_H */

drivers/staging/greybus/fw-core.c

@@ -9,9 +9,11 @@
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/firmware.h>
+#include "firmware.h"
 #include "greybus.h"
 
 struct gb_fw_core {
+	struct gb_connection	*download_connection;
 	struct gb_connection	*mgmt_connection;
 };
 
@@ -52,10 +54,29 @@ static int gb_fw_core_probe(struct gb_bundle *bundle,
 				dev_err(&bundle->dev,
 					"failed to create management connection (%d)\n",
 					ret);
-				goto err_free_fw_core;
+				goto err_destroy_connections;
 			}
 
 			fw_core->mgmt_connection = connection;
+			break;
+		case GREYBUS_PROTOCOL_FW_DOWNLOAD:
+			/* Disallow multiple Firmware Download CPorts */
+			if (fw_core->download_connection) {
+				dev_err(&bundle->dev,
+					"multiple download CPorts found\n");
+				ret = -EINVAL;
+				goto err_destroy_connections;
+			}
+
+			connection = gb_connection_create(bundle, cport_id,
+						gb_fw_download_request_handler);
+			if (IS_ERR(connection)) {
+				dev_err(&bundle->dev, "failed to create download connection (%ld)\n",
+					PTR_ERR(connection));
+			} else {
+				fw_core->download_connection = connection;
+			}
+
 			break;
 		default:
 			dev_err(&bundle->dev, "invalid protocol id (0x%02x)\n",
@@ -69,7 +90,16 @@ static int gb_fw_core_probe(struct gb_bundle *bundle,
 	if (!fw_core->mgmt_connection) {
 		dev_err(&bundle->dev, "missing management connection\n");
 		ret = -ENODEV;
-		goto err_free_fw_core;
+		goto err_destroy_connections;
+	}
+
+	ret = gb_fw_download_connection_init(fw_core->download_connection);
+	if (ret) {
+		/* We may still be able to work with the Interface */
+		dev_err(&bundle->dev, "failed to initialize firmware download connection, disable it (%d)\n",
+			ret);
+		gb_connection_destroy(fw_core->download_connection);
+		fw_core->download_connection = NULL;
 	}
 
 	greybus_set_drvdata(bundle, fw_core);
@@ -77,6 +107,7 @@ static int gb_fw_core_probe(struct gb_bundle *bundle,
 	return 0;
 
 err_destroy_connections:
+	gb_connection_destroy(fw_core->download_connection);
 	gb_connection_destroy(fw_core->mgmt_connection);
 err_free_fw_core:
 	kfree(fw_core);
@@ -88,6 +119,8 @@ static void gb_fw_core_disconnect(struct gb_bundle *bundle)
 {
 	struct gb_fw_core *fw_core = greybus_get_drvdata(bundle);
 
+	gb_fw_download_connection_exit(fw_core->download_connection);
+	gb_connection_destroy(fw_core->download_connection);
 	gb_connection_destroy(fw_core->mgmt_connection);
 
 	kfree(fw_core);

drivers/staging/greybus/fw-download.c

@@ -0,0 +1,299 @@
+/*
+ * Greybus Firmware Download Protocol Driver.
+ *
+ * Copyright 2016 Google Inc.
+ * Copyright 2016 Linaro Ltd.
+ *
+ * Released under the GPLv2 only.
+ */
+
+#include <linux/firmware.h>
+#include "firmware.h"
+#include "greybus.h"
+
+struct fw_request {
+	u8			firmware_id;
+	char			name[56]; /* ara_%08x_%08x_%08x_%08x_%s.tftf */
+	const struct firmware	*fw;
+	struct list_head	node;
+};
+
+struct fw_download {
+	struct device		*parent;
+	struct gb_connection	*connection;
+	struct list_head	fw_requests;
+	struct ida		id_map;
+};
+
+static struct fw_request *match_firmware(struct fw_download *fw_download,
+					 u8 firmware_id)
+{
+	struct fw_request *fw_req;
+
+	list_for_each_entry(fw_req, &fw_download->fw_requests, node) {
+		if (fw_req->firmware_id == firmware_id)
+			return fw_req;
+	}
+
+	return NULL;
+}
+
+static void free_firmware(struct fw_download *fw_download,
+			  struct fw_request *fw_req)
+{
+	list_del(&fw_req->node);
+	release_firmware(fw_req->fw);
+	ida_simple_remove(&fw_download->id_map, fw_req->firmware_id);
+	kfree(fw_req);
+}
+
+/* This returns path of the firmware blob on the disk */
+static struct fw_request *find_firmware(struct fw_download *fw_download,
+					const char *tag)
+{
+	struct gb_interface *intf = fw_download->connection->bundle->intf;
+	struct fw_request *fw_req;
+	int ret;
+
+	fw_req = kzalloc(sizeof(*fw_req), GFP_KERNEL);
+	if (!fw_req)
+		return ERR_PTR(-ENOMEM);
+
+	/* Allocate ids from 1 to 255 (u8-max), 0 is an invalid id */
+	ret = ida_simple_get(&fw_download->id_map, 1, 256, GFP_KERNEL);
+	if (ret < 0) {
+		dev_err(fw_download->parent,
+			"failed to allocate firmware id (%d)\n", ret);
+		goto err_free_req;
+	}
+	fw_req->firmware_id = ret;
+
+	snprintf(fw_req->name, sizeof(fw_req->name),
+		 "ara_%08x_%08x_%08x_%08x_%s.tftf",
+		 intf->ddbl1_manufacturer_id, intf->ddbl1_product_id,
+		 intf->vendor_id, intf->product_id, tag);
+
+	dev_info(fw_download->parent, "Requested firmware package '%s'\n",
+		 fw_req->name);
+
+	ret = request_firmware(&fw_req->fw, fw_req->name, fw_download->parent);
+	if (ret) {
+		dev_err(fw_download->parent,
+			"firmware request failed for %s (%d)\n", fw_req->name,
+			ret);
+		goto err_free_id;
+	}
+
+	list_add(&fw_req->node, &fw_download->fw_requests);
+
+	return fw_req;
+
+err_free_id:
+	ida_simple_remove(&fw_download->id_map, fw_req->firmware_id);
+err_free_req:
+	kfree(fw_req);
+
+	return ERR_PTR(ret);
+}
+
+static int fw_download_find_firmware(struct gb_operation *op)
+{
+	struct gb_connection *connection = op->connection;
+	struct fw_download *fw_download = gb_connection_get_data(connection);
+	struct gb_fw_download_find_firmware_request *request;
+	struct gb_fw_download_find_firmware_response *response;
+	struct fw_request *fw_req;
+	const char *tag;
+
+	if (op->request->payload_size != sizeof(*request)) {
+		dev_err(fw_download->parent,
+			"illegal size of find firmware request (%zu != %zu)\n",
+			op->request->payload_size, sizeof(*request));
+		return -EINVAL;
+	}
+
+	request = op->request->payload;
+	tag = (const char *)(request->firmware_tag);
+
+	/* firmware_tag should be null-terminated */
+	if (strnlen(tag, GB_FIRMWARE_TAG_MAX_LEN) == GB_FIRMWARE_TAG_MAX_LEN) {
+		dev_err(fw_download->parent,
+			"firmware-tag is not null-terminated\n");
+		return -EINVAL;
+	}
+
+	fw_req = find_firmware(fw_download, request->firmware_tag);
+	if (IS_ERR(fw_req))
+		return PTR_ERR(fw_req);
+
+	if (!gb_operation_response_alloc(op, sizeof(*response), GFP_KERNEL)) {
+		dev_err(fw_download->parent, "error allocating response\n");
+		free_firmware(fw_download, fw_req);
+		return -ENOMEM;
+	}
+
+	response = op->response->payload;
+	response->firmware_id = fw_req->firmware_id;
+	response->size = cpu_to_le32(fw_req->fw->size);
+
+	dev_dbg(fw_download->parent,
+		"firmware size is %zu bytes\n", fw_req->fw->size);
+
+	return 0;
+}
+
+static int fw_download_fetch_firmware(struct gb_operation *op)
+{
+	struct gb_connection *connection = op->connection;
+	struct fw_download *fw_download = gb_connection_get_data(connection);
+	struct gb_fw_download_fetch_firmware_request *request;
+	struct gb_fw_download_fetch_firmware_response *response;
+	struct fw_request *fw_req;
+	const struct firmware *fw;
+	unsigned int offset, size;
+	u8 firmware_id;
+
+	if (op->request->payload_size != sizeof(*request)) {
+		dev_err(fw_download->parent,
+			"Illegal size of fetch firmware request (%zu %zu)\n",
+			op->request->payload_size, sizeof(*request));
+		return -EINVAL;
+	}
+
+	request = op->request->payload;
+	offset = le32_to_cpu(request->offset);
+	size = le32_to_cpu(request->size);
+	firmware_id = request->firmware_id;
+
+	fw_req = match_firmware(fw_download, firmware_id);
+	if (!fw_req) {
+		dev_err(fw_download->parent,
+			"firmware not available for id: %02u\n", firmware_id);
+		return -EINVAL;
+	}
+
+	fw = fw_req->fw;
+
+	if (offset >= fw->size || size > fw->size - offset) {
+		dev_err(fw_download->parent,
+			"bad fetch firmware request (offs = %u, size = %u)\n",
+			offset, size);
+		return -EINVAL;
+	}
+
+	if (!gb_operation_response_alloc(op, sizeof(*response) + size,
+					 GFP_KERNEL)) {
+		dev_err(fw_download->parent,
+			"error allocating fetch firmware response\n");
+		return -ENOMEM;
+	}
+
+	response = op->response->payload;
+	memcpy(response->data, fw->data + offset, size);
+
+	dev_dbg(fw_download->parent,
+		"responding with firmware (offs = %u, size = %u)\n", offset,
+		size);
+
+	return 0;
+}
+
+static int fw_download_release_firmware(struct gb_operation *op)
+{
+	struct gb_connection *connection = op->connection;
+	struct fw_download *fw_download = gb_connection_get_data(connection);
+	struct gb_fw_download_release_firmware_request *request;
+	struct fw_request *fw_req;
+	u8 firmware_id;
+
+	if (op->request->payload_size != sizeof(*request)) {
+		dev_err(fw_download->parent,
+			"Illegal size of release firmware request (%zu %zu)\n",
+			op->request->payload_size, sizeof(*request));
+		return -EINVAL;
+	}
+
+	request = op->request->payload;
+	firmware_id = request->firmware_id;
+
+	fw_req = match_firmware(fw_download, firmware_id);
+	if (!fw_req) {
+		dev_err(fw_download->parent,
+			"firmware not available for id: %02u\n", firmware_id);
+		return -EINVAL;
+	}
+
+	free_firmware(fw_download, fw_req);
+
+	dev_dbg(fw_download->parent, "release firmware\n");
+
+	return 0;
+}
+
+int gb_fw_download_request_handler(struct gb_operation *op)
+{
+	u8 type = op->type;
+
+	switch (type) {
+	case GB_FW_DOWNLOAD_TYPE_FIND_FIRMWARE:
+		return fw_download_find_firmware(op);
+	case GB_FW_DOWNLOAD_TYPE_FETCH_FIRMWARE:
+		return fw_download_fetch_firmware(op);
+	case GB_FW_DOWNLOAD_TYPE_RELEASE_FIRMWARE:
+		return fw_download_release_firmware(op);
+	default:
+		dev_err(&op->connection->bundle->dev,
+			"unsupported request: %u\n", type);
+		return -EINVAL;
+	}
+}
+
+int gb_fw_download_connection_init(struct gb_connection *connection)
+{
+	struct fw_download *fw_download;
+	int ret;
+
+	if (!connection)
+		return 0;
+
+	fw_download = kzalloc(sizeof(*fw_download), GFP_KERNEL);
+	if (!fw_download)
+		return -ENOMEM;
+
+	fw_download->parent = &connection->bundle->dev;
+	INIT_LIST_HEAD(&fw_download->fw_requests);
+	ida_init(&fw_download->id_map);
+	gb_connection_set_data(connection, fw_download);
+	fw_download->connection = connection;
+
+	ret = gb_connection_enable(connection);
+	if (ret)
+		goto err_destroy_id_map;
+
+	return 0;
+
+err_destroy_id_map:
+	ida_destroy(&fw_download->id_map);
+	kfree(fw_download);
+
+	return ret;
+}
+
+void gb_fw_download_connection_exit(struct gb_connection *connection)
+{
+	struct fw_download *fw_download;
+	struct fw_request *fw_req, *tmp;
+
+	if (!connection)
+		return;
+
+	fw_download = gb_connection_get_data(connection);
+	gb_connection_disable(fw_download->connection);
+
+	/* Release pending firmware packages */
+	list_for_each_entry_safe(fw_req, tmp, &fw_download->fw_requests, node)
+		free_firmware(fw_download, fw_req);
+
+	ida_destroy(&fw_download->id_map);
+	kfree(fw_download);
+}

drivers/staging/greybus/greybus_protocols.h

@@ -213,6 +213,43 @@ struct gb_control_timesync_authoritative_request {
 #define GB_APB_REQUEST_CPORT_FEAT_EN	0x0b
 #define GB_APB_REQUEST_CPORT_FEAT_DIS	0x0c
 
+/* Firmware Download Protocol */
+
+/* Request Types */
+#define GB_FW_DOWNLOAD_TYPE_FIND_FIRMWARE	0x01
+#define GB_FW_DOWNLOAD_TYPE_FETCH_FIRMWARE	0x02
+#define GB_FW_DOWNLOAD_TYPE_RELEASE_FIRMWARE	0x03
+
+#define GB_FIRMWARE_TAG_MAX_LEN			10
+
+/* firmware download find firmware request/response */
+struct gb_fw_download_find_firmware_request {
+	__u8			firmware_tag[GB_FIRMWARE_TAG_MAX_LEN];
+} __packed;
+
+struct gb_fw_download_find_firmware_response {
+	__u8			firmware_id;
+	__le32			size;
+} __packed;
+
+/* firmware download fetch firmware request/response */
+struct gb_fw_download_fetch_firmware_request {
+	__u8			firmware_id;
+	__le32			offset;
+	__le32			size;
+} __packed;
+
+struct gb_fw_download_fetch_firmware_response {
+	__u8			data[0];
+} __packed;
+
+/* firmware download release firmware request */
+struct gb_fw_download_release_firmware_request {
+	__u8			firmware_id;
+} __packed;
+/* firmware download release firmware response has no payload */
+
+
 /* Bootrom Protocol */
 
 /* Version of the Greybus bootrom protocol we support */