mtd: brcmnand: iProc big endian and ONFI support

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Gitweb:     http://git.infradead.org/?p=mtd-2.6.git;a=commit;h=eab7fdc7bb84040537e4c6da5ad1b55a4bfec6e1
Commit:     eab7fdc7bb84040537e4c6da5ad1b55a4bfec6e1
Parent:     10ffd570f11701972aff2a6f91f3d253d6f0e7ee
Author:     Ray Jui <ray.jui at broadcom.com>
AuthorDate: Wed Jul 20 14:53:50 2016 -0700
Committer:  Boris Brezillon <boris.brezillon at free-electrons.com>
CommitDate: Fri Sep 23 09:35:16 2016 +0200

    mtd: brcmnand: iProc big endian and ONFI support
    
    This patch adds big endian and ONFI support for various iProc based
    SoCs that use the core brcmstb NAND controller
    
    This patch was originally implemented by Prafulla Kota
    <prafulla.kota at broadcom.com> and fully tested on iProc based NS2 SVK
    
    Signed-off-by: Prafulla Kota <prafulla.kota at broadcom.com>
    Signed-off-by: Ray Jui <ray.jui at broadcom.com>
    Reviewed-by: Kamal Dasu <kdasu.kdev at gmail.com>
    Acked-by: Kamal Dasu <kdasu.kdev at gmail.com>
    Signed-off-by: Boris Brezillon <boris.brezillon at free-electrons.com>
---
 drivers/mtd/nand/brcmnand/brcmnand.c   | 12 ++++++------
 drivers/mtd/nand/brcmnand/brcmnand.h   | 13 ++++++++-----
 drivers/mtd/nand/brcmnand/iproc_nand.c | 18 ++++++++++++++----
 3 files changed, 28 insertions(+), 15 deletions(-)

diff --git a/drivers/mtd/nand/brcmnand/brcmnand.c b/drivers/mtd/nand/brcmnand/brcmnand.c
index 82ec36b..9d2424b 100644
--- a/drivers/mtd/nand/brcmnand/brcmnand.c
+++ b/drivers/mtd/nand/brcmnand/brcmnand.c
@@ -1336,7 +1336,7 @@ static void brcmnand_cmdfunc(struct mtd_info *mtd, unsigned command,
 		u32 *flash_cache = (u32 *)ctrl->flash_cache;
 		int i;
 
-		brcmnand_soc_data_bus_prepare(ctrl->soc);
+		brcmnand_soc_data_bus_prepare(ctrl->soc, true);
 
 		/*
 		 * Must cache the FLASH_CACHE now, since changes in
@@ -1349,7 +1349,7 @@ static void brcmnand_cmdfunc(struct mtd_info *mtd, unsigned command,
 			 */
 			flash_cache[i] = be32_to_cpu(brcmnand_read_fc(ctrl, i));
 
-		brcmnand_soc_data_bus_unprepare(ctrl->soc);
+		brcmnand_soc_data_bus_unprepare(ctrl->soc, true);
 
 		/* Cleanup from HW quirk: restore SECTOR_SIZE_1K */
 		if (host->hwcfg.sector_size_1k)
@@ -1565,12 +1565,12 @@ static int brcmnand_read_by_pio(struct mtd_info *mtd, struct nand_chip *chip,
 		brcmnand_waitfunc(mtd, chip);
 
 		if (likely(buf)) {
-			brcmnand_soc_data_bus_prepare(ctrl->soc);
+			brcmnand_soc_data_bus_prepare(ctrl->soc, false);
 
 			for (j = 0; j < FC_WORDS; j++, buf++)
 				*buf = brcmnand_read_fc(ctrl, j);
 
-			brcmnand_soc_data_bus_unprepare(ctrl->soc);
+			brcmnand_soc_data_bus_unprepare(ctrl->soc, false);
 		}
 
 		if (oob)
@@ -1815,12 +1815,12 @@ static int brcmnand_write(struct mtd_info *mtd, struct nand_chip *chip,
 		(void)brcmnand_read_reg(ctrl, BRCMNAND_CMD_ADDRESS);
 
 		if (buf) {
-			brcmnand_soc_data_bus_prepare(ctrl->soc);
+			brcmnand_soc_data_bus_prepare(ctrl->soc, false);
 
 			for (j = 0; j < FC_WORDS; j++, buf++)
 				brcmnand_write_fc(ctrl, j, *buf);
 
-			brcmnand_soc_data_bus_unprepare(ctrl->soc);
+			brcmnand_soc_data_bus_unprepare(ctrl->soc, false);
 		} else if (oob) {
 			for (j = 0; j < FC_WORDS; j++)
 				brcmnand_write_fc(ctrl, j, 0xffffffff);
diff --git a/drivers/mtd/nand/brcmnand/brcmnand.h b/drivers/mtd/nand/brcmnand/brcmnand.h
index ef5eabb..5c44cd4 100644
--- a/drivers/mtd/nand/brcmnand/brcmnand.h
+++ b/drivers/mtd/nand/brcmnand/brcmnand.h
@@ -23,19 +23,22 @@ struct dev_pm_ops;
 struct brcmnand_soc {
 	bool (*ctlrdy_ack)(struct brcmnand_soc *soc);
 	void (*ctlrdy_set_enabled)(struct brcmnand_soc *soc, bool en);
-	void (*prepare_data_bus)(struct brcmnand_soc *soc, bool prepare);
+	void (*prepare_data_bus)(struct brcmnand_soc *soc, bool prepare,
+				 bool is_param);
 };
 
-static inline void brcmnand_soc_data_bus_prepare(struct brcmnand_soc *soc)
+static inline void brcmnand_soc_data_bus_prepare(struct brcmnand_soc *soc,
+						 bool is_param)
 {
 	if (soc && soc->prepare_data_bus)
-		soc->prepare_data_bus(soc, true);
+		soc->prepare_data_bus(soc, true, is_param);
 }
 
-static inline void brcmnand_soc_data_bus_unprepare(struct brcmnand_soc *soc)
+static inline void brcmnand_soc_data_bus_unprepare(struct brcmnand_soc *soc,
+						   bool is_param)
 {
 	if (soc && soc->prepare_data_bus)
-		soc->prepare_data_bus(soc, false);
+		soc->prepare_data_bus(soc, false, is_param);
 }
 
 static inline u32 brcmnand_readl(void __iomem *addr)
diff --git a/drivers/mtd/nand/brcmnand/iproc_nand.c b/drivers/mtd/nand/brcmnand/iproc_nand.c
index 585596c..4c6ae11 100644
--- a/drivers/mtd/nand/brcmnand/iproc_nand.c
+++ b/drivers/mtd/nand/brcmnand/iproc_nand.c
@@ -74,7 +74,8 @@ static void iproc_nand_intc_set(struct brcmnand_soc *soc, bool en)
 	spin_unlock_irqrestore(&priv->idm_lock, flags);
 }
 
-static void iproc_nand_apb_access(struct brcmnand_soc *soc, bool prepare)
+static void iproc_nand_apb_access(struct brcmnand_soc *soc, bool prepare,
+				  bool is_param)
 {
 	struct iproc_nand_soc *priv =
 			container_of(soc, struct iproc_nand_soc, soc);
@@ -86,10 +87,19 @@ static void iproc_nand_apb_access(struct brcmnand_soc *soc, bool prepare)
 
 	val = brcmnand_readl(mmio);
 
-	if (prepare)
-		val |= IPROC_NAND_APB_LE_MODE;
-	else
+	/*
+	 * In the case of BE or when dealing with NAND data, alway configure
+	 * the APB bus to LE mode before accessing the FIFO and back to BE mode
+	 * after the access is done
+	 */
+	if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) || !is_param) {
+		if (prepare)
+			val |= IPROC_NAND_APB_LE_MODE;
+		else
+			val &= ~IPROC_NAND_APB_LE_MODE;
+	} else { /* when in LE accessing the parameter page, keep APB in BE */
 		val &= ~IPROC_NAND_APB_LE_MODE;
+	}
 
 	brcmnand_writel(val, mmio);