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, 92 insertions, 7 deletions

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);
 	}