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>

6 files changed, 278 insertions, 7 deletions

diff --git a/target/linux/ar71xx/files/drivers/mtd/cybertan_part.c b/target/linux/ar71xx/files/drivers/mtd/cybertan_part.c
index 391411f8de..4d33c19b7e 100644
--- a/target/linux/ar71xx/files/drivers/mtd/cybertan_part.c
+++ b/target/linux/ar71xx/files/drivers/mtd/cybertan_part.c
@@ -28,6 +28,7 @@
 
 #include <linux/mtd/mtd.h>
 #include <linux/mtd/partitions.h>
+#include <linux/version.h>
 
 struct cybertan_header {
 	char	magic[4];
@@ -82,7 +83,11 @@ struct firmware_header {
 #define NVRAM_LEN	0x10000
 
 static int cybertan_parse_partitions(struct mtd_info *master,
+#if LINUX_VERSION_CODE < KERNEL_VERSION(4,5,0)
 				     struct mtd_partition **pparts,
+#else
+				     const struct mtd_partition **pparts,
+#endif
 				     struct mtd_part_parser_data *data)
 {
 	struct firmware_header *header;
diff --git a/target/linux/ar71xx/files/drivers/mtd/nand/ar934x_nfc.c b/target/linux/ar71xx/files/drivers/mtd/nand/ar934x_nfc.c
index a47fc0468e..a135e0f52f 100644
--- a/target/linux/ar71xx/files/drivers/mtd/nand/ar934x_nfc.c
+++ b/target/linux/ar71xx/files/drivers/mtd/nand/ar934x_nfc.c
@@ -18,6 +18,7 @@
 #include <linux/platform_device.h>
 #include <linux/delay.h>
 #include <linux/slab.h>
+#include <linux/version.h>
 
 #include <linux/platform/ar934x_nfc.h>
 
@@ -187,7 +188,9 @@ nfc_debug_data(const char *label, void *data, int len) {}
 #endif /* AR934X_NFC_DEBUG_DATA */
 
 struct ar934x_nfc {
+#if LINUX_VERSION_CODE < KERNEL_VERSION(4,6,0)
 	struct mtd_info mtd;
+#endif
 	struct nand_chip nand_chip;
 	struct device *parent;
 	void __iomem *base;
@@ -259,7 +262,22 @@ ar934x_nfc_get_platform_data(struct ar934x_nfc *nfc)
 static inline struct
 ar934x_nfc *mtd_to_ar934x_nfc(struct mtd_info *mtd)
 {
+#if LINUX_VERSION_CODE < KERNEL_VERSION(4,6,0)
 	return container_of(mtd, struct ar934x_nfc, mtd);
+#else
+	struct nand_chip *chip = mtd_to_nand(mtd);
+
+	return container_of(chip, struct ar934x_nfc, nand_chip);
+#endif
+}
+
+static struct mtd_info *ar934x_nfc_to_mtd(struct ar934x_nfc *nfc)
+{
+#if LINUX_VERSION_CODE < KERNEL_VERSION(4,6,0)
+	return &nfc->mtd;
+#else
+	return nand_to_mtd(&nfc->nand_chip);
+#endif
 }
 
 static inline bool ar934x_nfc_use_irq(struct ar934x_nfc *nfc)
@@ -648,7 +666,7 @@ ar934x_nfc_cmdfunc(struct mtd_info *mtd, unsigned int command, int column,
 		   int page_addr)
 {
 	struct ar934x_nfc *nfc = mtd_to_ar934x_nfc(mtd);
-	struct nand_chip *nand = mtd->priv;
+	struct nand_chip *nand = &nfc->nand_chip;
 
 	nfc->read_id = false;
 	if (command != NAND_CMD_PAGEPROG)
@@ -1241,6 +1259,7 @@ ar934x_nfc_init_tail(struct mtd_info *mtd)
 	return err;
 }
 
+#if LINUX_VERSION_CODE < KERNEL_VERSION(4,6,0)
 static struct nand_ecclayout ar934x_nfc_oob_64_hwecc = {
 	.eccbytes = 28,
 	.eccpos = {
@@ -1261,19 +1280,60 @@ static struct nand_ecclayout ar934x_nfc_oob_64_hwecc = {
 	},
 };
 
+#else
+
+static int ar934x_nfc_ooblayout_ecc(struct mtd_info *mtd, int section,
+				    struct mtd_oob_region *oobregion)
+{
+	if (section)
+		return -ERANGE;
+
+	oobregion->offset = 20;
+	oobregion->length = 28;
+
+	return 0;
+}
+
+static int ar934x_nfc_ooblayout_free(struct mtd_info *mtd, int section,
+				     struct mtd_oob_region *oobregion)
+{
+	switch (section) {
+	case 0:
+		oobregion->offset = 4;
+		oobregion->length = 16;
+		return 0;
+	case 1:
+		oobregion->offset = 48;
+		oobregion->length = 16;
+		return 0;
+	default:
+		return -ERANGE;
+	}
+}
+
+static const struct mtd_ooblayout_ops ar934x_nfc_ecclayout_ops = {
+	.ecc = ar934x_nfc_ooblayout_ecc,
+	.free = ar934x_nfc_ooblayout_free,
+};
+#endif /* < 4.6 */
+
 static int
 ar934x_nfc_setup_hwecc(struct ar934x_nfc *nfc)
 {
 	struct nand_chip *nand = &nfc->nand_chip;
+	struct mtd_info *mtd = ar934x_nfc_to_mtd(nfc);
 	u32 ecc_cap;
 	u32 ecc_thres;
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4,6,0)
+	struct mtd_oob_region oobregion;
+#endif
 
-	if (!config_enabled(CONFIG_MTD_NAND_AR934X_HW_ECC)) {
+	if (!IS_ENABLED(CONFIG_MTD_NAND_AR934X_HW_ECC)) {
 		dev_err(nfc->parent, "hardware ECC support is disabled\n");
 		return -EINVAL;
 	}
 
-	switch (nfc->mtd.writesize) {
+	switch (mtd->writesize) {
 	case 2048:
 		/*
 		 * Writing a subpage separately is not supported, because
@@ -1284,17 +1344,25 @@ ar934x_nfc_setup_hwecc(struct ar934x_nfc *nfc)
 		nand->ecc.size = 512;
 		nand->ecc.bytes = 7;
 		nand->ecc.strength = 4;
+#if LINUX_VERSION_CODE < KERNEL_VERSION(4,6,0)
 		nand->ecc.layout = &ar934x_nfc_oob_64_hwecc;
+#else
+		mtd_set_ooblayout(mtd, &ar934x_nfc_ecclayout_ops);
+#endif
 		break;
 
 	default:
 		dev_err(nfc->parent,
 			"hardware ECC is not available for %d byte pages\n",
-			nfc->mtd.writesize);
+			mtd->writesize);
 		return -EINVAL;
 	}
 
+#if LINUX_VERSION_CODE < KERNEL_VERSION(4,6,0)
 	BUG_ON(!nand->ecc.layout);
+#else
+	BUG_ON(!mtd->ooblayout->ecc);
+#endif
 
 	switch (nand->ecc.strength) {
 	case 4:
@@ -1309,12 +1377,17 @@ ar934x_nfc_setup_hwecc(struct ar934x_nfc *nfc)
 	}
 
 	nfc->ecc_thres = ecc_thres;
+#if LINUX_VERSION_CODE < KERNEL_VERSION(4,6,0)
 	nfc->ecc_oob_pos = nand->ecc.layout->eccpos[0];
+#else
+	mtd->ooblayout->ecc(mtd, 0, &oobregion);
+	nfc->ecc_oob_pos = oobregion.offset;
+#endif
 
 	nfc->ecc_ctrl_reg = ecc_cap << AR934X_NFC_ECC_CTRL_ECC_CAP_S;
 	nfc->ecc_ctrl_reg |= ecc_thres << AR934X_NFC_ECC_CTRL_ERR_THRES_S;
 
-	nfc->ecc_offset_reg = nfc->mtd.writesize + nfc->ecc_oob_pos;
+	nfc->ecc_offset_reg = mtd->writesize + nfc->ecc_oob_pos;
 
 	nand->ecc.mode = NAND_ECC_HW;
 	nand->ecc.read_page = ar934x_nfc_read_page;
@@ -1382,9 +1455,11 @@ ar934x_nfc_probe(struct platform_device *pdev)
 	nfc->swap_dma = pdata->swap_dma;
 
 	nand = &nfc->nand_chip;
-	mtd = &nfc->mtd;
+	mtd = ar934x_nfc_to_mtd(nfc);
 
+#if LINUX_VERSION_CODE < KERNEL_VERSION(4,6,0)
 	mtd->priv = nand;
+#endif
 	mtd->owner = THIS_MODULE;
 	if (pdata->name)
 		mtd->name = pdata->name;
@@ -1429,10 +1504,18 @@ ar934x_nfc_probe(struct platform_device *pdev)
 	switch (pdata->ecc_mode) {
 	case AR934X_NFC_ECC_SOFT:
 		nand->ecc.mode = NAND_ECC_SOFT;
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4,6,0)
+		nand->ecc.algo = NAND_ECC_HAMMING;
+#endif
 		break;
 
 	case AR934X_NFC_ECC_SOFT_BCH:
+#if LINUX_VERSION_CODE < KERNEL_VERSION(4,6,0)
 		nand->ecc.mode = NAND_ECC_SOFT_BCH;
+#else
+		nand->ecc.mode = NAND_ECC_SOFT;
+		nand->ecc.algo = NAND_ECC_BCH;
+#endif
 		break;
 
 	case AR934X_NFC_ECC_HW:
@@ -1474,10 +1557,12 @@ static int
 ar934x_nfc_remove(struct platform_device *pdev)
 {
 	struct ar934x_nfc *nfc;
+	struct mtd_info *mtd;
 
 	nfc = platform_get_drvdata(pdev);
 	if (nfc) {
-		nand_release(&nfc->mtd);
+		mtd = ar934x_nfc_to_mtd(nfc);
+		nand_release(mtd);
 		ar934x_nfc_free_buf(nfc);
 		free_irq(nfc->irq, nfc);
 	}
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) {
diff --git a/target/linux/ar71xx/files/drivers/mtd/nand/rb750_nand.c b/target/linux/ar71xx/files/drivers/mtd/nand/rb750_nand.c
index 0604c5a235..f8a6722cba 100644
--- a/target/linux/ar71xx/files/drivers/mtd/nand/rb750_nand.c
+++ b/target/linux/ar71xx/files/drivers/mtd/nand/rb750_nand.c
@@ -16,6 +16,7 @@
 #include <linux/platform_device.h>
 #include <linux/io.h>
 #include <linux/slab.h>
+#include <linux/version.h>
 
 #include <asm/mach-ath79/ar71xx_regs.h>
 #include <asm/mach-ath79/ath79.h>
@@ -49,6 +50,7 @@ static inline struct rb750_nand_info *mtd_to_rbinfo(struct mtd_info *mtd)
 	return container_of(mtd, struct rb750_nand_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.
@@ -60,6 +62,56 @@ static struct nand_ecclayout rb750_nand_ecclayout = {
 	.oobfree	= { { 0, 4 }, { 6, 2 }, { 11, 2 }, { 4, 1 } }
 };
 
+#else
+
+static int rb750_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 rb750_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 rb750_nand_ecclayout_ops = {
+	.ecc = rb750_ooblayout_ecc,
+	.free = rb750_ooblayout_free,
+};
+#endif /* < 4.6 */
+
 static struct mtd_partition rb750_nand_partitions[] = {
 	{
 		.name	= "booter",
@@ -292,7 +344,11 @@ static int rb750_nand_probe(struct platform_device *pdev)
 	}
 
 	if (info->mtd.writesize == 512)
+#if LINUX_VERSION_CODE < KERNEL_VERSION(4,6,0)
 		info->chip.ecc.layout = &rb750_nand_ecclayout;
+#else
+		mtd_set_ooblayout(&info->mtd, &rb750_nand_ecclayout_ops);
+#endif
 
 	ret = nand_scan_tail(&info->mtd);
 	if (ret) {
diff --git a/target/linux/ar71xx/files/drivers/mtd/nand/rb91x_nand.c b/target/linux/ar71xx/files/drivers/mtd/nand/rb91x_nand.c
index 1308e18ba6..15b1816ae1 100644
--- a/target/linux/ar71xx/files/drivers/mtd/nand/rb91x_nand.c
+++ b/target/linux/ar71xx/files/drivers/mtd/nand/rb91x_nand.c
@@ -19,6 +19,7 @@
 #include <linux/slab.h>
 #include <linux/gpio.h>
 #include <linux/platform_data/rb91x_nand.h>
+#include <linux/version.h>
 
 #include <asm/mach-ath79/ar71xx_regs.h>
 #include <asm/mach-ath79/ath79.h>
@@ -56,6 +57,7 @@ static inline struct rb91x_nand_info *mtd_to_rbinfo(struct mtd_info *mtd)
 	return container_of(mtd, struct rb91x_nand_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.
@@ -67,6 +69,56 @@ static struct nand_ecclayout rb91x_nand_ecclayout = {
 	.oobfree	= { { 0, 4 }, { 6, 2 }, { 11, 2 }, { 4, 1 } }
 };
 
+#else
+
+static int rb91x_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 rb91x_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 rb91x_nand_ecclayout_ops = {
+	.ecc = rb91x_ooblayout_ecc,
+	.free = rb91x_ooblayout_free,
+};
+#endif /* < 4.6 */
+
 static struct mtd_partition rb91x_nand_partitions[] = {
 	{
 		.name	= "booter",
@@ -334,7 +386,11 @@ static int rb91x_nand_probe(struct platform_device *pdev)
 		return ret;
 
 	if (rbni->mtd.writesize == 512)
+#if LINUX_VERSION_CODE < KERNEL_VERSION(4,6,0)
 		rbni->chip.ecc.layout = &rb91x_nand_ecclayout;
+#else
+		mtd_set_ooblayout(&rbni->mtd, &rb91x_nand_ecclayout_ops);
+#endif
 
 	ret = nand_scan_tail(&rbni->mtd);
 	if (ret)
diff --git a/target/linux/ar71xx/files/drivers/mtd/tplinkpart.c b/target/linux/ar71xx/files/drivers/mtd/tplinkpart.c
index ac1efa1c22..1b94163b83 100644
--- a/target/linux/ar71xx/files/drivers/mtd/tplinkpart.c
+++ b/target/linux/ar71xx/files/drivers/mtd/tplinkpart.c
@@ -15,6 +15,7 @@
 
 #include <linux/mtd/mtd.h>
 #include <linux/mtd/partitions.h>
+#include <linux/version.h>
 
 #define TPLINK_NUM_PARTS	5
 #define TPLINK_HEADER_V1	0x01000000
@@ -109,7 +110,11 @@ static int tplink_check_rootfs_magic(struct mtd_info *mtd, size_t offset)
 }
 
 static int tplink_parse_partitions_offset(struct mtd_info *master,
+#if LINUX_VERSION_CODE < KERNEL_VERSION(4,5,0)
 				   struct mtd_partition **pparts,
+#else
+				   const struct mtd_partition **pparts,
+#endif
 				   struct mtd_part_parser_data *data,
 				   size_t offset)
 {
@@ -181,7 +186,11 @@ err:
 }
 
 static int tplink_parse_partitions(struct mtd_info *master,
+#if LINUX_VERSION_CODE < KERNEL_VERSION(4,5,0)
 				   struct mtd_partition **pparts,
+#else
+				   const struct mtd_partition **pparts,
+#endif
 				   struct mtd_part_parser_data *data)
 {
 	return tplink_parse_partitions_offset(master, pparts, data,
@@ -189,7 +198,11 @@ static int tplink_parse_partitions(struct mtd_info *master,
 }
 
 static int tplink_parse_64k_partitions(struct mtd_info *master,
+#if LINUX_VERSION_CODE < KERNEL_VERSION(4,5,0)
 				   struct mtd_partition **pparts,
+#else
+				   const struct mtd_partition **pparts,
+#endif
 				   struct mtd_part_parser_data *data)
 {
 	return tplink_parse_partitions_offset(master, pparts, data,