[U-Boot] [PATCH RESEND 3/7] spi: cadence_qspi: remove sram polling from flash write

Vikas Manocha
2015-06-17T02:14:21Z

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@st.com>
---
drivers/spi/cadence_qspi_apb.c | 59 ++++++++++------------------------------
1 file changed, 15 insertions(+), 44 deletions(-)

diff --git a/drivers/spi/cadence_qspi_apb.c b/drivers/spi/cadence_qspi_apb.c
index 794d51d..403230a 100644
--- a/drivers/spi/cadence_qspi_apb.c
+++ b/drivers/spi/cadence_qspi_apb.c
@@ -220,63 +220,34 @@ 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;
- int remaining = bytes;
- unsigned int *dest_ptr = (unsigned int *)dest_ahb_addr;
- unsigned int *src_ptr = (unsigned int *)src;
-
- while (remaining > 0) {
- if (remaining >= CQSPI_FIFO_WIDTH) {
- writel(*src_ptr, dest_ptr);
- remaining -= sizeof(unsigned int);
- } else {
- /* dangling bytes */
- memcpy(&temp, src_ptr, remaining);
- writel(temp, dest_ptr);
- break;
- }
- src_ptr++;
- }
-
- 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