From 0a0093b0bc8671d3a00cf1bb71d56cabab9474e1 Mon Sep 17 00:00:00 2001
From: Anup Patel <anup.patel@wdc.com>
Date: Sat, 25 Apr 2020 18:33:54 +0530
Subject: [PATCH] lib: utils: Add fdt_parse_uart8250_node() function

We add fdt_parse_uart8250_node() function which will allow us
to parse a particular DT node as UART 8250 node. This will be
useful in parsing the node pointed by stdout-path.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
---
 include/sbi_utils/fdt/fdt_helper.h |  3 +++
 lib/utils/fdt/fdt_helper.c         | 37 +++++++++++++++++++-----------
 2 files changed, 26 insertions(+), 14 deletions(-)

diff --git a/include/sbi_utils/fdt/fdt_helper.h b/include/sbi_utils/fdt/fdt_helper.h
index d3cc791e..1fbc215e 100644
--- a/include/sbi_utils/fdt/fdt_helper.h
+++ b/include/sbi_utils/fdt/fdt_helper.h
@@ -23,6 +23,9 @@ struct platform_plic_data {
 	unsigned long num_src;
 };
 
+int fdt_parse_uart8250_node(void *fdt, int nodeoffset,
+			    struct platform_uart_data *uart);
+
 int fdt_parse_uart8250(void *fdt, struct platform_uart_data *uart,
 		       const char *compatible);
 
diff --git a/lib/utils/fdt/fdt_helper.c b/lib/utils/fdt/fdt_helper.c
index f620e742..4757f19c 100644
--- a/lib/utils/fdt/fdt_helper.c
+++ b/lib/utils/fdt/fdt_helper.c
@@ -58,21 +58,15 @@ static int fdt_get_node_addr_size(void *fdt, int node, unsigned long *addr,
 	return 0;
 }
 
-int fdt_parse_uart8250(void *fdt, struct platform_uart_data *uart,
-		   const char *compatible)
+int fdt_parse_uart8250_node(void *fdt, int nodeoffset,
+			    struct platform_uart_data *uart)
 {
-	int nodeoffset, len, rc;
-	fdt32_t *val;
+	int len, rc;
+	const fdt32_t *val;
 	unsigned long reg_addr, reg_size;
 
-	/**
-	 * TODO: We don't know how to handle multiple nodes with the same
-	 * compatible sring. Just return the first node for now.
-	 */
-
-	nodeoffset = fdt_node_offset_by_compatible(fdt, -1, compatible);
-	if (nodeoffset < 0)
-		return nodeoffset;
+	if (nodeoffset < 0 || !uart || !fdt)
+		return SBI_ENODEV;
 
 	rc = fdt_get_node_addr_size(fdt, nodeoffset, &reg_addr, &reg_size);
 	if (rc < 0 || !reg_addr || !reg_size)
@@ -80,8 +74,8 @@ int fdt_parse_uart8250(void *fdt, struct platform_uart_data *uart,
 	uart->addr = reg_addr;
 
 	/**
-	 * UART address is mandaotry. clock-frequency and current-speed may not
-	 * be present. Don't return error.
+	 * UART address is mandaotry. clock-frequency and current-speed
+	 * may not be present. Don't return error.
 	 */
 	val = (fdt32_t *)fdt_getprop(fdt, nodeoffset, "clock-frequency", &len);
 	if (len > 0 && val)
@@ -110,6 +104,21 @@ int fdt_parse_uart8250(void *fdt, struct platform_uart_data *uart,
 	return 0;
 }
 
+int fdt_parse_uart8250(void *fdt, struct platform_uart_data *uart,
+		   const char *compatible)
+{
+	int nodeoffset;
+
+	if (!compatible || !uart || !fdt)
+		return SBI_ENODEV;
+
+	nodeoffset = fdt_node_offset_by_compatible(fdt, -1, compatible);
+	if (nodeoffset < 0)
+		return nodeoffset;
+
+	return fdt_parse_uart8250_node(fdt, nodeoffset, uart);
+}
+
 int fdt_parse_plic(void *fdt, struct platform_plic_data *plic,
 		   const char *compatible)
 {