[U-Boot] [PATCH 2/6] spi: cadence_qspi: remove sram polling from flash write

[Vikas Manocha]

There is no need to poll sram level before writing to flash, data going to SRAM
till sram is full, after that backpressure will take over.

Signed-off-by: Vikas Manocha <vikas.manocha at st.com>
---
 drivers/spi/cadence_qspi_apb.c |   63 ++++++++++------------------------------
 1 file changed, 16 insertions(+), 47 deletions(-)

diff --git a/drivers/spi/cadence_qspi_apb.c b/drivers/spi/cadence_qspi_apb.c
index 32cbc23..313f6ac 100644
--- a/drivers/spi/cadence_qspi_apb.c
+++ b/drivers/spi/cadence_qspi_apb.c
@@ -213,66 +213,35 @@ static int cadence_qspi_apb_read_fifo_data(void *dest,
 	return 0;
 }
 
-static void cadence_qspi_apb_write_fifo_data(const void *dest_ahb_addr,
-	const void *src, unsigned int bytes)
-{
-	unsigned int temp=0;
-	int i;
-	int remaining = bytes;
-	unsigned int *dest_ptr = (unsigned int *)dest_ahb_addr;
-	unsigned int *src_ptr = (unsigned int *)src;
-
-	while (remaining >= CQSPI_FIFO_WIDTH) {
-		for (i = CQSPI_FIFO_WIDTH/sizeof(src_ptr) - 1; i >= 0; i--)
-			writel(*(src_ptr+i), dest_ptr+i);
-		src_ptr += CQSPI_FIFO_WIDTH/sizeof(src_ptr);
-		remaining -= CQSPI_FIFO_WIDTH;
-	}
-	if (remaining)
-	{
-		/* dangling bytes */
-		i = remaining/sizeof(dest_ptr);
-		memcpy(&temp, src_ptr+i, remaining % sizeof(dest_ptr));
-		writel(temp, dest_ptr+i);
-		for (--i; i >= 0; i--)
-			writel(*(src_ptr+i), dest_ptr+i);
-	}
-	return;
-}
-
-/* Write to SRAM FIFO with polling SRAM fill level. */
 static int qpsi_write_sram_fifo_push(struct cadence_spi_platdata *plat,
 				const void *src_addr, unsigned int num_bytes)
 {
-	const void *reg_base = plat->regbase;
-	void *dest_addr = plat->ahbbase;
-	unsigned int retry = CQSPI_REG_RETRY;
-	unsigned int sram_level;
+	int i = 0;
+	unsigned int *dest_addr = plat->trigger_base;
 	unsigned int wr_bytes;
-	unsigned char *src = (unsigned char *)src_addr;
+	unsigned int *src_ptr = (unsigned int *)src_addr;
 	int remaining = num_bytes;
 	unsigned int page_size = plat->page_size;
-	unsigned int sram_threshold_words = CQSPI_REG_SRAM_THRESHOLD_WORDS;
 
 	while (remaining > 0) {
-		retry = CQSPI_REG_RETRY;
-		while (retry--) {
-			sram_level = CQSPI_GET_WR_SRAM_LEVEL(reg_base);
-			if (sram_level <= sram_threshold_words)
-				break;
-		}
-		if (!retry) {
-			printf("QSPI: SRAM fill level (0x%08x) not hit lower expected level (0x%08x)",
-			       sram_level, sram_threshold_words);
-			return -1;
-		}
 		/* Write a page or remaining bytes. */
 		wr_bytes = (remaining > page_size) ?
 					page_size : remaining;
 
-		cadence_qspi_apb_write_fifo_data(dest_addr, src, wr_bytes);
-		src += wr_bytes;
 		remaining -= wr_bytes;
+		while (wr_bytes >= CQSPI_FIFO_WIDTH) {
+			for (i = 0; i < CQSPI_FIFO_WIDTH/sizeof(dest_addr); i++)
+				writel(*(src_ptr+i), dest_addr+i);
+			src_ptr += CQSPI_FIFO_WIDTH/sizeof(dest_addr);
+			wr_bytes -= CQSPI_FIFO_WIDTH;
+		}
+		if (wr_bytes)
+		{
+			/* dangling bytes */
+			i = wr_bytes/sizeof(dest_addr);
+			for (i = wr_bytes/sizeof(dest_addr); i >= 0; i--)
+				writel(*(src_ptr+i), dest_addr+i);
+		}
 	}
 
 	return 0;
-- 
1.7.9.5