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, 56 insertions, 0 deletions

diff --git a/target/linux/ar71xx/files/drivers/mtd/nand/rb4xx_nand.c b/target/linux/ar71xx/files/drivers/mtd/nand/rb4xx_nand.c
index 96ec5dd1e5..b397575f77 100644
--- a/target/linux/ar71xx/files/drivers/mtd/nand/rb4xx_nand.c
+++ b/target/linux/ar71xx/files/drivers/mtd/nand/rb4xx_nand.c
@@ -23,6 +23,7 @@
 #include <linux/io.h>
 #include <linux/gpio.h>
 #include <linux/slab.h>
+#include <linux/version.h>
 
 #include <asm/mach-ath79/ath79.h>
 #include <asm/mach-ath79/rb4xx_cpld.h>
@@ -41,6 +42,7 @@ struct rb4xx_nand_info {
 	struct mtd_info		mtd;
 };
 
+#if LINUX_VERSION_CODE < KERNEL_VERSION(4,6,0)
 /*
  * We need to use the OLD Yaffs-1 OOB layout, otherwise the RB bootloader
  * will not be able to find the kernel that we load.
@@ -52,6 +54,56 @@ static struct nand_ecclayout rb4xx_nand_ecclayout = {
 	.oobfree	= { { 0, 4 }, { 6, 2 }, { 11, 2 }, { 4, 1 } }
 };
 
+#else
+
+static int rb4xx_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 rb4xx_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 rb4xx_nand_ecclayout_ops = {
+	.ecc = rb4xx_ooblayout_ecc,
+	.free = rb4xx_ooblayout_free,
+};
+#endif /* < 4.6 */
+
 static struct mtd_partition rb4xx_nand_partitions[] = {
 	{
 		.name	= "booter",
@@ -229,7 +281,11 @@ static int rb4xx_nand_probe(struct platform_device *pdev)
 	}
 
 	if (info->mtd.writesize == 512)
+#if LINUX_VERSION_CODE < KERNEL_VERSION(4,6,0)
 		info->chip.ecc.layout = &rb4xx_nand_ecclayout;
+#else
+		mtd_set_ooblayout(&info->mtd, &rb4xx_nand_ecclayout_ops);
+#endif
 
 	ret = nand_scan_tail(&info->mtd);
 	if (ret) {