mtd: parsers: bcm63xx: simplify CFE detection

Instead of trying to parse CFE version string, which is customized by some
vendors, let's just check that "CFE1" was passed on argument 3.

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20200615091740.2958303-1-noltari@gmail.com

diff --git a/drivers/mtd/parsers/bcm63xxpart.c b/drivers/mtd/parsers/bcm63xxpart.c
index 78f90c6..b15bdad 100644 (file)
--- a/drivers/mtd/parsers/bcm63xxpart.c
+++ b/drivers/mtd/parsers/bcm63xxpart.c
@@ -22,6 +22,11 @@
 #include <linux/mtd/partitions.h>
 #include <linux/of.h>
 
+#ifdef CONFIG_MIPS
+#include <asm/bootinfo.h>
+#include <asm/fw/cfe/cfe_api.h>
+#endif /* CONFIG_MIPS */
+
 #define BCM963XX_CFE_BLOCK_SIZE                SZ_64K  /* always at least 64KiB */
 
 #define BCM963XX_CFE_MAGIC_OFFSET      0x4e0
@@ -32,28 +37,15 @@
 #define STR_NULL_TERMINATE(x) \
        do { char *_str = (x); _str[sizeof(x) - 1] = 0; } while (0)
 
-static int bcm63xx_detect_cfe(struct mtd_info *master)
+static inline int bcm63xx_detect_cfe(void)
 {
-       char buf[9];
-       int ret;
-       size_t retlen;
+       int ret = 0;
 
-       ret = mtd_read(master, BCM963XX_CFE_VERSION_OFFSET, 5, &retlen,
-                      (void *)buf);
-       buf[retlen] = 0;
+#ifdef CONFIG_MIPS
+       ret = (fw_arg3 == CFE_EPTSEAL);
+#endif /* CONFIG_MIPS */
 
-       if (ret)
-               return ret;
-
-       if (strncmp("cfe-v", buf, 5) == 0)
-               return 0;
-
-       /* very old CFE's do not have the cfe-v string, so check for magic */
-       ret = mtd_read(master, BCM963XX_CFE_MAGIC_OFFSET, 8, &retlen,
-                      (void *)buf);
-       buf[retlen] = 0;
-
-       return strncmp("CFE1CFE1", buf, 8);
+       return ret;
 }
 
 static int bcm63xx_read_nvram(struct mtd_info *master,
@@ -138,7 +130,7 @@ static int bcm63xx_parse_cfe_partitions(struct mtd_info *master,
        struct bcm963xx_nvram *nvram = NULL;
        int ret;
 
-       if (bcm63xx_detect_cfe(master))
+       if (!bcm63xx_detect_cfe())
                return -EINVAL;
 
        nvram = vzalloc(sizeof(*nvram));