[PATCH v4 3/3] cmd: Fixup DT to pass PStore Ramoops parameters

[Frédéric Danis]

To simplify configuration and keep synchronized the PStore/Ramoops between
U-Boot and the Linux kernel, this commit dynamically adds the Ramoops
parameters defined in the U-Boot session to the Device Tree.

Signed-off-by: Frédéric Danis <frederic.danis at collabora.com>
---
 cmd/pstore.c          | 38 ++++++++++++++++++++++++++++++++++++++
 common/image-fdt.c    |  4 ++++
 doc/pstore.rst        |  2 ++
 include/fdt_support.h |  3 +++
 4 files changed, 47 insertions(+)

diff --git a/cmd/pstore.c b/cmd/pstore.c
index 4e4d70d604..6cad635620 100644
--- a/cmd/pstore.c
+++ b/cmd/pstore.c
@@ -479,6 +479,44 @@ static int do_pstore(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 	return c->cmd(cmdtp, flag, argc, argv);
 }
 
+void fdt_fixup_pstore(void *blob)
+{
+	char node[32];
+	int  nodeoffset;	/* node offset from libfdt */
+
+	nodeoffset = fdt_path_offset(blob, "/");
+	if (nodeoffset < 0) {
+		/* Not found or something else bad happened. */
+		log_debug("fdt_path_offset() returned %s\n", fdt_strerror(nodeoffset));
+		return;
+	}
+
+	nodeoffset = fdt_add_subnode(blob, nodeoffset, "reserved-memory");
+	if (nodeoffset < 0) {
+		log_debug("Add 'reserved-memory' node failed: %s\n",
+				fdt_strerror(nodeoffset));
+		return;
+	}
+	fdt_appendprop_u32(blob, nodeoffset, "#address-cells", 2);
+	fdt_appendprop_u32(blob, nodeoffset, "#size-cells", 2);
+	fdt_appendprop(blob, nodeoffset, "ranges", NULL, 0);
+
+	sprintf(node, "ramoops@%llx", (unsigned long long)pstore_addr);
+	nodeoffset = fdt_add_subnode(blob, nodeoffset, node);
+	if (nodeoffset < 0) {
+		log_debug("Add '%s' node failed: %s\n", node, fdt_strerror(nodeoffset));
+		return;
+	}
+	fdt_appendprop_string(blob, nodeoffset, "compatible", "ramoops");
+	fdt_appendprop_u64(blob, nodeoffset, "reg", pstore_addr);
+	fdt_appendprop_u64(blob, nodeoffset, "reg", pstore_length);
+	fdt_appendprop_u32(blob, nodeoffset, "record-size", pstore_record_size);
+	fdt_appendprop_u32(blob, nodeoffset, "console-size", pstore_console_size);
+	fdt_appendprop_u32(blob, nodeoffset, "ftrace-size", pstore_ftrace_size);
+	fdt_appendprop_u32(blob, nodeoffset, "pmsg-size", pstore_pmsg_size);
+	fdt_appendprop_u32(blob, nodeoffset, "ecc-size", pstore_ecc_size);
+}
+
 U_BOOT_CMD(pstore, 10, 0, do_pstore,
 	   "Manage Linux Persistent Storage",
 	   "set <addr> <len> [record-size] [console-size] [ftrace-size] [pmsg_size] [ecc-size]\n"
diff --git a/common/image-fdt.c b/common/image-fdt.c
index 3002948b6b..491d55ad1a 100644
--- a/common/image-fdt.c
+++ b/common/image-fdt.c
@@ -547,6 +547,10 @@ int image_setup_libfdt(bootm_headers_t *images, void *blob,
 	}
 	/* Update ethernet nodes */
 	fdt_fixup_ethernet(blob);
+#if CONFIG_IS_ENABLED(CMD_PSTORE)
+	/* Append PStore configuration */
+	fdt_fixup_pstore(blob);
+#endif
 	if (IMAGE_OF_BOARD_SETUP) {
 		fdt_ret = ft_board_setup(blob, gd->bd);
 		if (fdt_ret) {
diff --git a/doc/pstore.rst b/doc/pstore.rst
index 90a8e1c2cb..0038249976 100644
--- a/doc/pstore.rst
+++ b/doc/pstore.rst
@@ -24,6 +24,8 @@ i.e.::
 
 The same values should be set in U-Boot to be able to retrieve the records.
 This values can be set at build time in U-Boot configuration file, or at runtime.
+U-Boot automatically patches the Device Tree to pass the Ramoops parameters to
+the kernel.
 
 The PStore configuration parameters are:
 
diff --git a/include/fdt_support.h b/include/fdt_support.h
index ba14acd7f6..7afbdcfe37 100644
--- a/include/fdt_support.h
+++ b/include/fdt_support.h
@@ -350,4 +350,7 @@ int fdt_update_ethernet_dt(void *blob);
 #ifdef CONFIG_FSL_MC_ENET
 void fdt_fixup_board_enet(void *blob);
 #endif
+#ifdef CONFIG_CMD_PSTORE
+void fdt_fixup_pstore(void *blob);
+#endif
 #endif /* ifndef __FDT_SUPPORT_H */
-- 
2.18.0