ar71xx: Add kernel 4.9 support

This add support for kernel 4.9 to the ar71xx target.
It was compile tested with the generic, NAND and mikrotik subtarget.
Multiple members of the community tested it on their boards and did not
report any major problem so far.

Especially the NAND part received some changes to adapt to the new
kernel APIs. The serial driver hack used for the Arduino Yun was not
ported because the kernel changed there a lot.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>

1 files changed, 58 insertions, 0 deletions

diff --git a/target/linux/ar71xx/files/arch/mips/ath79/mach-rb922.c b/target/linux/ar71xx/files/arch/mips/ath79/mach-rb922.c
index 0c5373c365..577fb0eee0 100644
--- a/target/linux/ar71xx/files/arch/mips/ath79/mach-rb922.c
+++ b/target/linux/ar71xx/files/arch/mips/ath79/mach-rb922.c
@@ -20,6 +20,7 @@
 #include <linux/routerboot.h>
 #include <linux/gpio.h>
 #include <linux/platform_data/phy-at803x.h>
+#include <linux/version.h>
 
 #include <asm/prom.h>
 #include <asm/mach-ath79/ath79.h>
@@ -132,6 +133,7 @@ static void rb922gs_nand_select_chip(int chip_no)
 	ndelay(500);
 }
 
+#if LINUX_VERSION_CODE < KERNEL_VERSION(4,6,0)
 static struct nand_ecclayout rb922gs_nand_ecclayout = {
 	.eccbytes	= 6,
 	.eccpos		= { 8, 9, 10, 13, 14, 15 },
@@ -139,16 +141,72 @@ static struct nand_ecclayout rb922gs_nand_ecclayout = {
 	.oobfree	= { { 0, 4 }, { 6, 2 }, { 11, 2 }, { 4, 1 } }
 };
 
+#else
+
+static int rb922gs_ooblayout_ecc(struct mtd_info *mtd, int section,
+				 struct mtd_oob_region *oobregion)
+{
+	switch (section) {
+	case 0:
+		oobregion->offset = 8;
+		oobregion->length = 3;
+		return 0;
+	case 1:
+		oobregion->offset = 13;
+		oobregion->length = 3;
+		return 0;
+	default:
+		return -ERANGE;
+	}
+}
+
+static int rb922gs_ooblayout_free(struct mtd_info *mtd, int section,
+				  struct mtd_oob_region *oobregion)
+{
+	switch (section) {
+	case 0:
+		oobregion->offset = 0;
+		oobregion->length = 4;
+		return 0;
+	case 1:
+		oobregion->offset = 4;
+		oobregion->length = 1;
+		return 0;
+	case 2:
+		oobregion->offset = 6;
+		oobregion->length = 2;
+		return 0;
+	case 3:
+		oobregion->offset = 11;
+		oobregion->length = 2;
+		return 0;
+	default:
+		return -ERANGE;
+	}
+}
+
+static const struct mtd_ooblayout_ops rb922gs_nand_ecclayout_ops = {
+	.ecc = rb922gs_ooblayout_ecc,
+	.free = rb922gs_ooblayout_free,
+};
+#endif /* < 4.6 */
+
 static int rb922gs_nand_scan_fixup(struct mtd_info *mtd)
 {
+#if LINUX_VERSION_CODE < KERNEL_VERSION(4,6,0)
 	struct nand_chip *chip = mtd->priv;
+#endif
 
 	if (mtd->writesize == 512) {
 		/*
 		 * Use the OLD Yaffs-1 OOB layout, otherwise RouterBoot
 		 * will not be able to find the kernel that we load.
 		 */
+#if LINUX_VERSION_CODE < KERNEL_VERSION(4,6,0)
 		chip->ecc.layout = &rb922gs_nand_ecclayout;
+#else
+		mtd_set_ooblayout(mtd, &rb922gs_nand_ecclayout_ops);
+#endif
 	}
 
 	return 0;