[MTD NAND] Split nand_scan() into two parts; allow board driver to intervene (3b85c321) · Commits · e / devices / android_kernel_fairphone_FP3

drivers/mtd/nand/nand_base.c

+65 −25

Original line number	Diff line number	Diff line
		@@ -2289,40 +2289,22 @@ static struct nand_flash_dev nand_get_flash_type(struct mtd_info mtd,
		return type;
		}

		/* module_text_address() isn't exported, and it's mostly a pointless
		test if this is a module _anyway_ -- they'd have to try _really_ hard
		to call us from in-kernel code if the core NAND support is modular. */
		#ifdef MODULE
		#define caller_is_module() (1)
		#else
		#define caller_is_module() \
		module_text_address((unsigned long)__builtin_return_address(0))
		#endif

		/**
		* nand_scan - [NAND Interface] Scan for the NAND device
		* nand_scan_ident - [NAND Interface] Scan for the NAND device
		* @mtd: MTD device structure
		* @maxchips: Number of chips to scan for
		*
		* This fills out all the uninitialized function pointers
		* with the defaults.
		* The flash ID is read and the mtd/chip structures are
		* filled with the appropriate values.
		* The mtd->owner field must be set to the module of the caller
		* This is the first phase of the normal nand_scan() function. It
		* reads the flash ID and sets up MTD fields accordingly.
		*
		* The mtd->owner field must be set to the module of the caller.
		*/
		int nand_scan(struct mtd_info *mtd, int maxchips)
		int nand_scan_ident(struct mtd_info *mtd, int maxchips)
		{
		int i, busw, nand_maf_id;
		struct nand_chip *chip = mtd->priv;
		struct nand_flash_dev *type;

		/* Many callers got this wrong, so check for it for a while... */
		if (!mtd->owner && caller_is_module()) {
		printk(KERN_CRIT "nand_scan() called with NULL mtd->owner!\n");
		BUG();
		}

		/* Get buswidth to select the correct functions */
		busw = chip->options & NAND_BUSWIDTH_16;
		/* Set the default functions */
		@@ -2354,6 +2336,24 @@ int nand_scan(struct mtd_info *mtd, int maxchips)
		chip->numchips = i;
		mtd->size = i * chip->chipsize;

		return 0;
		}


		/**
		* nand_scan_tail - [NAND Interface] Scan for the NAND device
		* @mtd: MTD device structure
		* @maxchips: Number of chips to scan for
		*
		* This is the second phase of the normal nand_scan() function. It
		* fills out all the uninitialized function pointers with the defaults
		* and scans for a bad block table if appropriate.
		*/
		int nand_scan_tail(struct mtd_info *mtd)
		{
		int i;
		struct nand_chip *chip = mtd->priv;

		/* Preset the internal oob write buffer */
		memset(chip->buffers.oobwbuf, 0xff, mtd->oobsize);

		@@ -2504,6 +2504,44 @@ int nand_scan(struct mtd_info *mtd, int maxchips)
		return chip->scan_bbt(mtd);
		}

		/* module_text_address() isn't exported, and it's mostly a pointless
		test if this is a module _anyway_ -- they'd have to try _really_ hard
		to call us from in-kernel code if the core NAND support is modular. */
		#ifdef MODULE
		#define caller_is_module() (1)
		#else
		#define caller_is_module() \
		module_text_address((unsigned long)__builtin_return_address(0))
		#endif

		/**
		* nand_scan - [NAND Interface] Scan for the NAND device
		* @mtd: MTD device structure
		* @maxchips: Number of chips to scan for
		*
		* This fills out all the uninitialized function pointers
		* with the defaults.
		* The flash ID is read and the mtd/chip structures are
		* filled with the appropriate values.
		* The mtd->owner field must be set to the module of the caller
		*
		*/
		int nand_scan(struct mtd_info *mtd, int maxchips)
		{
		int ret;

		/* Many callers got this wrong, so check for it for a while... */
		if (!mtd->owner && caller_is_module()) {
		printk(KERN_CRIT "nand_scan() called with NULL mtd->owner!\n");
		BUG();
		}

		ret = nand_scan_ident(mtd, maxchips);
		if (!ret)
		ret = nand_scan_tail(mtd);
		return ret;
		}

		/**
		* nand_release - [NAND Interface] Free resources held by the NAND device
		* @mtd: MTD device structure
		@@ -2524,6 +2562,8 @@ void nand_release(struct mtd_info *mtd)
		}

		EXPORT_SYMBOL_GPL(nand_scan);
		EXPORT_SYMBOL_GPL(nand_scan_ident);
		EXPORT_SYMBOL_GPL(nand_scan_tail);
		EXPORT_SYMBOL_GPL(nand_release);

		static int __init nand_base_init(void)

include/linux/mtd/nand.h

+5 −0

Original line number	Diff line number	Diff line
		@@ -27,6 +27,11 @@
		struct mtd_info;
		/* Scan and identify a NAND device */
		extern int nand_scan (struct mtd_info *mtd, int max_chips);
		/* Separate phases of nand_scan(), allowing board driver to intervene
		* and override command or ECC setup according to flash type */
		extern int nand_scan_ident(struct mtd_info *mtd, int max_chips);
		extern int nand_scan_tail(struct mtd_info *mtd);

		/* Free resources held by the NAND device */
		extern void nand_release (struct mtd_info *mtd);