ralink: add missing nand layer hack

It turned out that mtk_nand driver uses some sophisticated accounting and a
general nand code must be patched.

This patch adds required read and erase calls to a general nand code. I
used a  code  for re6500 released by Linksys as a reference.

All required operations (erase, write and read) are usable. However I found
that jffs2 filesystem can be created only on top of a ubi volume. I tried
to create jffs2 directly on mtd device but pages with clean markers are
became uncorrectable.

Signed-off-by: Kirill Berezin <fyiwdt@gmail.com>

SVN-Revision: 47565

1 files changed, 179 insertions, 0 deletions

diff --git a/target/linux/ramips/patches-3.18/0075-mtk_nand_alloc_buffer.patch b/target/linux/ramips/patches-3.18/0075-mtk_nand_alloc_buffer.patch
new file mode 100644
index 0000000..ac20198
--- /dev/null
+++ b/target/linux/ramips/patches-3.18/0075-mtk_nand_alloc_buffer.patch
@@ -0,0 +1,179 @@
+From patchwork Fri Nov 13 07:55:08 2015
+Content-Type: text/plain; charset="utf-8"
+MIME-Version: 1.0
+Content-Transfer-Encoding: 7bit
+Subject: [OpenWrt-Devel,RFC] A patch for mt7621 nand controler. Revision 2.
+From: Kirill Berezin <fyiwdt@gmail.com>
+X-Patchwork-Id: 544092
+Message-Id: <CAOFwh=DZieEa4ZA0ex6G3OR2OgEeP6Fh+SSw=Zg-L0wWm1QRTA@mail.gmail.com>
+To: openwrt-devel@lists.openwrt.org
+Date: Fri, 13 Nov 2015 10:55:08 +0300
+
+Hello,
+
+It turned out that mtk_nand driver uses some sophisticated accounting and a
+general nand code must be patched.
+
+This patch adds required read and erase calls to a general nand code. I
+used a  code  for re6500 released by Linksys as a reference.
+
+All required operations (erase, write and read) are usable. However I found
+that jffs2 filesystem can be created only on top of a ubi volume. I tried
+to create jffs2 directly on mtd device but pages with clean markers are
+became uncorrectable.
+
+This patch also includes changes that I sent earlier.
+
+Best regards,
+Kirill.
+
+Signed-off-by: Kirill Berezin (fyiwdt@gmail.com)
+
+diff -urNb a/drivers/mtd/nand/mtk_nand.c b/drivers/mtd/nand/mtk_nand.c
+--- a/drivers/mtd/nand/mtk_nand.c	2015-11-06 16:44:31.000000000 +0400
++++ b/drivers/mtd/nand/mtk_nand.c	2015-11-12 10:06:20.080430855 +0400
+@@ -110,6 +110,10 @@
+ int manu_id;
+ int dev_id;
+ 
++/* this constant was taken from linux/nand/nand.h v 3.14
++ * in later versions it seems it was removed in order to save a bit of space
++ */
++#define NAND_MAX_OOBSIZE 774
+ static u8 local_oob_buf[NAND_MAX_OOBSIZE];
+ 
+ static u8 nand_badblock_offset = 0;
+@@ -348,7 +352,7 @@
+ 		if (0xF == u4ErrNum) {
+ 			mtd->ecc_stats.failed++;
+ 			bRet = false;
+-			//printk(KERN_ERR"UnCorrectable at PageAddr=%d\n", u4PageAddr);
++			printk(KERN_ERR"mtk_nand: UnCorrectable at PageAddr=%d\n", u4PageAddr);
+ 		} else {
+ 			for (i = 0; i < ((u4ErrNum + 1) >> 1); ++i) {
+ 				au4ErrBitLoc[i] = DRV_Reg32(ECC_DECEL0_REG32 + i);
+@@ -1422,7 +1426,7 @@
+ {
+ 	struct nand_chip *chip = (struct nand_chip *)mtd->priv;
+ 
+-	chip->erase_cmd(mtd, page);
++	chip->erase(mtd, page);
+ 
+ 	return chip->waitfunc(mtd, chip);
+ }
+@@ -2094,8 +2098,8 @@
+ 	nand_chip->write_page = mtk_nand_write_page;
+ 	nand_chip->ecc.write_oob = mtk_nand_write_oob;
+ 	nand_chip->block_markbad = mtk_nand_block_markbad;   // need to add nand_get_device()/nand_release_device().
+-	//	nand_chip->erase = mtk_nand_erase;	
+-	//    nand_chip->read_page = mtk_nand_read_page;
++	nand_chip->erase_mtk = mtk_nand_erase;	
++	nand_chip->read_page = mtk_nand_read_page;
+ 	nand_chip->ecc.read_oob = mtk_nand_read_oob;
+ 	nand_chip->block_bad = mtk_nand_block_bad;
+ 
+@@ -2175,6 +2179,21 @@
+ 	nand_chip->pagemask = (nand_chip->chipsize >> nand_chip->page_shift) - 1;
+ 	nand_chip->phys_erase_shift = ffs(mtd->erasesize) - 1;
+ 	nand_chip->chip_shift = ffs(nand_chip->chipsize) - 1;//0x1C;//ffs(nand_chip->chipsize) - 1;
++
++	/* allocate buffers or call select_chip here or a bit earlier*/
++	{
++		struct nand_buffers *nbuf = kzalloc(sizeof(*nbuf) + mtd->writesize + mtd->oobsize * 3, GFP_KERNEL);
++		if (!nbuf) {
++			return -ENOMEM;
++		}
++		nbuf->ecccalc = (uint8_t *)(nbuf + 1);
++		nbuf->ecccode = nbuf->ecccalc + mtd->oobsize;
++		nbuf->databuf = nbuf->ecccode + mtd->oobsize;
++
++		nand_chip->buffers = nbuf;
++		nand_chip->options |= NAND_OWN_BUFFERS;
++	}
++
+ 	nand_chip->oob_poi = nand_chip->buffers->databuf + mtd->writesize;
+ 	nand_chip->badblockpos = 0;
+ 
+@@ -2251,6 +2270,9 @@
+ 	MSG(INIT, "[NFI] mtk_nand_probe fail, err = %d!\n", err);
+ 	nand_release(mtd);
+ 	platform_set_drvdata(pdev, NULL);
++	if ( NULL != nand_chip->buffers) {
++		kfree(nand_chip->buffers);
++	}
+ 	kfree(host);
+ 	nand_disable_clock();
+ 	return err;
+@@ -2261,8 +2283,12 @@
+ {
+ 	struct mtk_nand_host *host = platform_get_drvdata(pdev);
+ 	struct mtd_info *mtd = &host->mtd;
++	struct nand_chip *nand_chip = &host->nand_chip;
+ 
+ 	nand_release(mtd);
++	if ( NULL != nand_chip->buffers) {
++		kfree(nand_chip->buffers);
++	}
+ 	kfree(host);
+ 	nand_disable_clock();
+ 
+diff -urNb a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
+--- a/drivers/mtd/nand/nand_base.c	2015-11-06 16:44:31.000000000 +0400
++++ b/drivers/mtd/nand/nand_base.c	2015-11-09 10:24:52.931720862 +0400
+@@ -1575,6 +1575,9 @@
+ 						 __func__, buf);
+ 
+ read_retry:
++#ifdef CONFIG_MTK_MTD_NAND
++			ret = chip->read_page(mtd, chip, bufpoi, page);
++#else
+ 			chip->cmdfunc(mtd, NAND_CMD_READ0, 0x00, page);
+ 
+ 			/*
+@@ -1593,6 +1596,7 @@
+ 			else
+ 				ret = chip->ecc.read_page(mtd, chip, bufpoi,
+ 							  oob_required, page);
++#endif /* CONFIG_MTK_MTD_NAND */
+ 			if (ret < 0) {
+ 				if (use_bufpoi)
+ 					/* Invalidate page cache */
+@@ -2770,8 +2774,11 @@
+ 		if (page <= chip->pagebuf && chip->pagebuf <
+ 		    (page + pages_per_block))
+ 			chip->pagebuf = -1;
+-
++#ifdef CONFIG_MTK_MTD_NAND
++		status = chip->erase_mtk(mtd, page & chip->pagemask);
++#else
+ 		status = chip->erase(mtd, page & chip->pagemask);
++#endif /* CONFIG_MTK_MTD_NAND */
+ 
+ 		/*
+ 		 * See if operation failed and additional status checks are
+diff -urNb a/drivers/mtd/nand/nand_device_list.h b/drivers/mtd/nand/nand_device_list.h
+--- a/drivers/mtd/nand/nand_device_list.h	2015-11-06 16:44:31.000000000 +0400
++++ b/drivers/mtd/nand/nand_device_list.h	2015-11-06 11:13:26.000000000 +0400
+@@ -43,6 +43,8 @@
+ 	{0xADBC, 0x905554, 5, 16, 512, 128, 2048, 64, 0x10801011, "H9DA4GH4JJAMC", 0},
+     {0x01F1, 0x801D01, 4, 8, 128, 128, 2048, 64, 0x30C77fff, "S34ML01G100TF", 0},
+     {0x92F1, 0x8095FF, 4, 8, 128, 128, 2048, 64, 0x30C77fff, "F59L1G81A", 0},
++	{0xC8DA, 0x909544, 5, 8, 256, 128, 2048, 64, 0x30C77fff, "F59L2G81A", 0},
++	{0xC8DC, 0x909554, 5, 8, 512, 128, 2048, 64, 0x30C77fff, "F59L4G81A", 0},
+ 	{0xECD3, 0x519558, 5, 8, 1024, 128, 2048, 64, 0x44333, "K9K8G8000", 0},
+     {0xC2F1, 0x801DC2, 4, 8, 128, 128, 2048, 64, 0x30C77fff, "MX30LF1G08AA", 0},
+     {0x98D3, 0x902676, 5, 8, 1024, 256, 4096, 224, 0x00C25332, "TC58NVG3S0F", 0},
+diff -urNb a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h
+--- a/include/linux/mtd/nand.h	2015-11-06 16:44:30.000000000 +0400
++++ b/include/linux/mtd/nand.h	2015-11-09 10:18:55.704701886 +0400
+@@ -653,6 +653,10 @@
+ 	int (*write_page)(struct mtd_info *mtd, struct nand_chip *chip,
+ 			uint32_t offset, int data_len, const uint8_t *buf,
+ 			int oob_required, int page, int cached, int raw);
++#ifdef CONFIG_MTK_MTD_NAND
++	int (*read_page)(struct mtd_info *mtd, struct nand_chip *chip, u8 *buf, int page);
++	int (*erase_mtk)(struct mtd_info *mtd, int page);
++#endif /* CONFIG_MTK_MTD_NAND */
+ 	int (*onfi_set_features)(struct mtd_info *mtd, struct nand_chip *chip,
+ 			int feature_addr, uint8_t *subfeature_para);
+ 	int (*onfi_get_features)(struct mtd_info *mtd, struct nand_chip *chip,