[PATCH v3 05/10] mtd: rawnand: brcmnand: Add BCMBCA read data bus interface

David Regan
2024-01-24T03:07:11Z

From: William Zhang <william.zhang@broadcom.com>

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>
---
Changes in v3:
- Updated bcmbca_read_data_bus comment
---
Changes in v2:
- Drop the is_param argument to the read data bus function now that we
have the exec_op API to read the parameter page and ONFI data
- Remove be32_to_cpu from brcmnand_read_data_bus
---
drivers/mtd/nand/raw/brcmnand/bcmbca_nand.c | 27 +++++++++++++++++++++
drivers/mtd/nand/raw/brcmnand/brcmnand.c | 20 ++++++++++++---
drivers/mtd/nand/raw/brcmnand/brcmnand.h | 2 ++
3 files changed, 46 insertions(+), 3 deletions(-)

diff --git a/drivers/mtd/nand/raw/brcmnand/bcmbca_nand.c b/drivers/mtd/nand/raw/brcmnand/bcmbca_nand.c
index 3e2f3b79788d..7ad3e7a98f97 100644
--- 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 8faca43ae1ff..73fdf7ce21aa 100644
--- 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 928114c0be5e..7261a69989fe 100644
--- 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;
};

--
2.37.3