bcm53xx: add brcmnand patch reading flash parameters

It's useful for adding support for new hardware.

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>

SVN-Revision: 48603

target/linux/bcm53xx/patches-4.4/140-mtd-brcmnand-set-initial-ECC-params-based-on-info-fr.patch

@@ -0,0 +1,53 @@
+From eff78bc2c385f592294278582f38ad5fa4ed2b34 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <zajec5@gmail.com>
+Date: Wed, 27 Jan 2016 08:47:03 +0100
+Subject: [PATCH] mtd: brcmnand: set initial ECC params based on info from HW
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+So far we were depending on nand_dt_init getting ECC info from DT and
+setting it in ECC struct. It is possible to simply read this info from
+hardware registers which makes adding support for new hardware way
+easier (no more guessing & trying all combinations).
+Please note it still gives a precedence to DT which was overwrite
+whatever was initially set by the driver.
+
+Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
+---
+It took me hours to figure out how to setup NAND on my D-Link DIR-885L.
+This should be very helpful for ppl adding new devices support.
+---
+ drivers/mtd/nand/brcmnand/brcmnand.c | 14 ++++++++++++++
+ 1 file changed, 14 insertions(+)
+
+--- a/drivers/mtd/nand/brcmnand/brcmnand.c
++++ b/drivers/mtd/nand/brcmnand/brcmnand.c
+@@ -613,6 +613,17 @@ static inline u32 brcmnand_ecc_level_mas
+ 	return mask << NAND_ACC_CONTROL_ECC_SHIFT;
+ }
+ 
++static int brcmnand_get_ecc_strength(struct brcmnand_host *host)
++{
++	struct brcmnand_controller *ctrl = host->ctrl;
++	u32 mask = brcmnand_ecc_level_mask(ctrl);
++	u16 acc_control_offs = brcmnand_cs_offset(ctrl, host->cs,
++						  BRCMNAND_CS_ACC_CONTROL);
++
++	return (nand_readreg(ctrl, acc_control_offs) & mask) >>
++		NAND_ACC_CONTROL_ECC_SHIFT;
++}
++
+ static void brcmnand_set_ecc_enabled(struct brcmnand_host *host, int en)
+ {
+ 	struct brcmnand_controller *ctrl = host->ctrl;
+@@ -1965,6 +1976,9 @@ static int brcmnand_init_cs(struct brcmn
+ 	nand_writereg(ctrl, cfg_offs,
+ 		      nand_readreg(ctrl, cfg_offs) & ~CFG_BUS_WIDTH);
+ 
++	chip->ecc.strength = brcmnand_get_ecc_strength(host);
++	chip->ecc.size = brcmnand_get_sector_size_1k(host) ? 1024 : 512;
++
+ 	if (nand_scan_ident(mtd, 1, NULL))
+ 		return -ENXIO;
+