mtd: rawnand: brcmnand: Add BCMBCA read data bus interface

The BCMBCA broadband SoC integrates the NAND controller differently than
STB, iProc and other SoCs.  It has different endianness for NAND cache
data.

Add a SoC read data bus shim for BCMBCA to meet the specific SoC need
and performance improvement using the optimized memcpy function on NAND
cache memory.

Signed-off-by: William Zhang <william.zhang@broadcom.com>
Reviewed-by: David Regan <dregan@broadcom.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20240223034758.13753-12-william.zhang@broadcom.com

diff --git a/drivers/mtd/nand/raw/brcmnand/bcmbca_nand.c b/drivers/mtd/nand/raw/brcmnand/bcmbca_nand.c
index 3e2f3b7..7ad3e7a 100644 (file)
--- a/drivers/mtd/nand/raw/brcmnand/bcmbca_nand.c
+++ b/drivers/mtd/nand/raw/brcmnand/bcmbca_nand.c
@@ -26,6 +26,18 @@ enum {
        BCMBCA_CTLRDY           = BIT(4),
 };
 
+#if defined(CONFIG_ARM64)
+#define ALIGN_REQ              8
+#else
+#define ALIGN_REQ              4
+#endif
+
+static inline bool bcmbca_nand_is_buf_aligned(void *flash_cache,  void *buffer)
+{
+       return IS_ALIGNED((uintptr_t)buffer, ALIGN_REQ) &&
+                               IS_ALIGNED((uintptr_t)flash_cache, ALIGN_REQ);
+}
+
 static bool bcmbca_nand_intc_ack(struct brcmnand_soc *soc)
 {
        struct bcmbca_nand_soc *priv =
@@ -56,6 +68,20 @@ static void bcmbca_nand_intc_set(struct brcmnand_soc *soc, bool en)
        brcmnand_writel(val, mmio);
 }
 
+static void bcmbca_read_data_bus(struct brcmnand_soc *soc,
+                                void __iomem *flash_cache,  u32 *buffer, int fc_words)
+{
+       /*
+        * memcpy can do unaligned aligned access depending on source
+        * and dest address, which is incompatible with nand cache. Fallback
+        * to the memcpy_fromio in such case
+        */
+       if (bcmbca_nand_is_buf_aligned((void *)flash_cache, buffer))
+               memcpy((void *)buffer, (void *)flash_cache, fc_words * 4);
+       else
+               memcpy_fromio((void *)buffer, flash_cache, fc_words * 4);
+}
+
 static int bcmbca_nand_probe(struct platform_device *pdev)
 {
        struct device *dev = &pdev->dev;
@@ -73,6 +99,7 @@ static int bcmbca_nand_probe(struct platform_device *pdev)
 
        soc->ctlrdy_ack = bcmbca_nand_intc_ack;
        soc->ctlrdy_set_enabled = bcmbca_nand_intc_set;
+       soc->read_data_bus = bcmbca_read_data_bus;
 
        return brcmnand_probe(pdev, soc);
 }

diff --git a/drivers/mtd/nand/raw/brcmnand/brcmnand.c b/drivers/mtd/nand/raw/brcmnand/brcmnand.c
index f1f0de5..ef7d340 100644 (file)
--- a/drivers/mtd/nand/raw/brcmnand/brcmnand.c
+++ b/drivers/mtd/nand/raw/brcmnand/brcmnand.c
@@ -851,6 +851,20 @@ static inline u32 edu_readl(struct brcmnand_controller *ctrl,
        return brcmnand_readl(ctrl->edu_base + offs);
 }
 
+static inline void brcmnand_read_data_bus(struct brcmnand_controller *ctrl,
+                                         void __iomem *flash_cache, u32 *buffer, int fc_words)
+{
+       struct brcmnand_soc *soc = ctrl->soc;
+       int i;
+
+       if (soc->read_data_bus) {
+               soc->read_data_bus(soc, flash_cache, buffer, fc_words);
+       } else {
+               for (i = 0; i < fc_words; i++)
+                       buffer[i] = brcmnand_read_fc(ctrl, i);
+       }
+}
+
 static void brcmnand_clear_ecc_addr(struct brcmnand_controller *ctrl)
 {
 
@@ -1975,7 +1989,7 @@ static int brcmnand_read_by_pio(struct mtd_info *mtd, struct nand_chip *chip,
 {
        struct brcmnand_host *host = nand_get_controller_data(chip);
        struct brcmnand_controller *ctrl = host->ctrl;
-       int i, j, ret = 0;
+       int i, ret = 0;
 
        brcmnand_clear_ecc_addr(ctrl);
 
@@ -1988,8 +2002,8 @@ static int brcmnand_read_by_pio(struct mtd_info *mtd, struct nand_chip *chip,
                if (likely(buf)) {
                        brcmnand_soc_data_bus_prepare(ctrl->soc, false);
 
-                       for (j = 0; j < FC_WORDS; j++, buf++)
-                               *buf = brcmnand_read_fc(ctrl, j);
+                       brcmnand_read_data_bus(ctrl, ctrl->nand_fc, buf, FC_WORDS);
+                       buf += FC_WORDS;
 
                        brcmnand_soc_data_bus_unprepare(ctrl->soc, false);
                }

diff --git a/drivers/mtd/nand/raw/brcmnand/brcmnand.h b/drivers/mtd/nand/raw/brcmnand/brcmnand.h
index 928114c..9f17125 100644 (file)
--- a/drivers/mtd/nand/raw/brcmnand/brcmnand.h
+++ b/drivers/mtd/nand/raw/brcmnand/brcmnand.h
@@ -24,6 +24,8 @@ struct brcmnand_soc {
        void (*ctlrdy_set_enabled)(struct brcmnand_soc *soc, bool en);
        void (*prepare_data_bus)(struct brcmnand_soc *soc, bool prepare,
                                 bool is_param);
+       void (*read_data_bus)(struct brcmnand_soc *soc, void __iomem *flash_cache,
+                             u32 *buffer, int fc_words);
        const struct brcmnand_io_ops *ops;
 };