diff options
| author | Marek Vasut <marek.vasut+renesas@gmail.com> | 2018-04-10 17:43:47 +0300 |
|---|---|---|
| committer | Marek Vasut <marex@denx.de> | 2018-04-12 00:19:51 +0300 |
| commit | ea5512eb095067dda27930246792d2957feb9434 (patch) | |
| tree | 986de767a326a218faa5c3bed94c9abc19eb54bd /drivers/spi | |
| parent | 9573db654d1999a1dfde6469782aa8d7cf3d589f (diff) | |
| download | u-boot-ea5512eb095067dda27930246792d2957feb9434.tar.xz | |
spi: sh_qspi: Make use of the 32byte FIFO
The QSPI controller on RCar Gen2 has 32byte FIFO. Instead of doing
the SPI transmission 1 byte at time, if there is a 32byte chunk of
data to be transferred, fill the FIFO completely and then transfer
the data to/from the FIFO. This increases the SPI NOR access speed
significantly.
Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
Diffstat (limited to 'drivers/spi')
| -rw-r--r-- | drivers/spi/sh_qspi.c | 34 |
1 files changed, 24 insertions, 10 deletions
diff --git a/drivers/spi/sh_qspi.c b/drivers/spi/sh_qspi.c index d7f558a541..5075be3cd1 100644 --- a/drivers/spi/sh_qspi.c +++ b/drivers/spi/sh_qspi.c @@ -36,6 +36,8 @@ SPCMD_BRDV0 #define SPBFCR_TXRST BIT(7) #define SPBFCR_RXRST BIT(6) +#define SPBFCR_TXTRG 0x30 +#define SPBFCR_RXTRG 0x07 /* SH QSPI register set */ struct sh_qspi_regs { @@ -201,8 +203,8 @@ int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout, void *din, unsigned long flags) { struct sh_qspi_slave *ss = to_sh_qspi(slave); - u32 nbyte; - int ret = 0; + u32 nbyte, chunk; + int i, ret = 0; u8 dtdata = 0, drdata; u8 *tdata = &dtdata, *rdata = &drdata; u32 *spbmul0 = &ss->regs->spbmul0; @@ -237,26 +239,38 @@ int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout, rdata = din; while (nbyte > 0) { + /* + * Check if there is 32 Byte chunk and if there is, transfer + * it in one burst, otherwise transfer on byte-by-byte basis. + */ + chunk = (nbyte >= 32) ? 32 : 1; + + clrsetbits_8(&ss->regs->spbfcr, SPBFCR_TXTRG | SPBFCR_RXTRG, + chunk == 32 ? SPBFCR_TXTRG | SPBFCR_RXTRG : 0); + ret = wait_for_bit_8(&ss->regs->spsr, SPSR_SPTEF, true, 1000, true); if (ret) return ret; - writeb(*tdata, (u8 *)(&ss->regs->spdr)); + for (i = 0; i < chunk; i++) { + writeb(*tdata, &ss->regs->spdr); + if (dout != NULL) + tdata++; + } ret = wait_for_bit_8(&ss->regs->spsr, SPSR_SPRFF, true, 1000, true); if (ret) return ret; - *rdata = readb((u8 *)(&ss->regs->spdr)); - - if (dout != NULL) - tdata++; - if (din != NULL) - rdata++; + for (i = 0; i < chunk; i++) { + *rdata = readb(&ss->regs->spdr); + if (din != NULL) + rdata++; + } - nbyte--; + nbyte -= chunk; } if (flags & SPI_XFER_END) |