[PATCH v2 1/4] firmware: Add request/release_firmware() calls

[Philipp Zabel <p.zabel@pengutronix.de>]

Add request_firmware() and release_firmware() calls that allow drivers
to load a firmware file. Also move the struct firmware definition from
remoteproc.h into firmware.h.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
---
v2:
- let request_firmware() stub return -EINVAL instead of -EOPNOTSUPP
- drop spurious #include <unistd.h>
---
 common/firmware.c          | 32 ++++++++++++++++++++++++++++++++
 include/firmware.h         | 16 ++++++++++++++++
 include/linux/remoteproc.h |  5 -----
 3 files changed, 48 insertions(+), 5 deletions(-)

diff --git a/common/firmware.c b/common/firmware.c
index e4ad6ac867b0..6dc621d3081d 100644
--- a/common/firmware.c
+++ b/common/firmware.c
@@ -304,6 +304,38 @@ out:
 	return ret;
 }
 
+/*
+ * request_firmware - load a firmware to a device
+ */
+int request_firmware(const struct firmware **out, const char *fw_name, struct device *dev)
+{
+	char fw_path[PATH_MAX + 1];
+	struct firmware *fw;
+	int ret;
+
+	fw = kzalloc(sizeof(struct firmware), GFP_KERNEL);
+	if (!fw)
+		return -ENOMEM;
+
+	snprintf(fw_path, sizeof(fw_path), "%s/%s", firmware_path, fw_name);
+
+	ret = read_file_2(fw_path, &fw->size, (void *)&fw->data, FILESIZE_MAX);
+	if (ret) {
+		kfree(fw);
+		return ret;
+	}
+
+	*out = fw;
+
+	return 0;
+}
+
+void release_firmware(const struct firmware *fw)
+{
+	kfree_const(fw->data);
+	kfree_const(fw);
+}
+
 static int firmware_init(void)
 {
 	firmware_path = strdup("/env/firmware");
diff --git a/include/firmware.h b/include/firmware.h
index 05433f2f7858..93c800e11bfd 100644
--- a/include/firmware.h
+++ b/include/firmware.h
@@ -13,6 +13,11 @@
 #include <debug_ll.h>
 #include <linux/kernel.h>
 
+struct firmware {
+	size_t size;
+	const u8 *data;
+};
+
 struct firmware_handler {
 	char *id; /* unique identifier for this firmware device */
 	char *model; /* description for this device */
@@ -37,6 +42,8 @@ struct firmware_mgr *firmwaremgr_find_by_node(struct device_node *np);
 int firmwaremgr_load_file(struct firmware_mgr *, const char *path);
 char *firmware_get_searchpath(void);
 void firmware_set_searchpath(const char *path);
+int request_firmware(const struct firmware **fw, const char *fw_name, struct device *dev);
+void release_firmware(const struct firmware *fw);
 #else
 static inline struct firmware_mgr *firmwaremgr_find_by_node(struct device_node *np)
 {
@@ -57,6 +64,15 @@ static inline void firmware_set_searchpath(const char *path)
 {
 }
 
+static inline int request_firmware(const struct firmware **fw, const char *fw_name,
+				   struct device *dev)
+{
+	return -EINVAL;
+}
+
+static inline void release_firmware(const struct firmware *fw)
+{
+}
 #endif
 
 void firmwaremgr_list_handlers(void);
diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
index 170fff7987fb..33fe2f81b748 100644
--- a/include/linux/remoteproc.h
+++ b/include/linux/remoteproc.h
@@ -18,11 +18,6 @@ struct resource_table {
 	u32 offset[0];
 } __packed;
 
-struct firmware {
-	size_t size;
-	const u8 *data;
-};
-
 struct rproc;
 
 struct rproc_ops {
-- 
2.39.2