From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jean Pihet Subject: [PATCH 2/2] spi: spi-ti-qspi: optimize byte-transfers Date: Tue, 14 Jan 2020 13:41:25 +0100 Message-ID: <20200114124125.361429-3-jean.pihet@newoldbits.com> References: <20200114124125.361429-1-jean.pihet@newoldbits.com> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Cc: linux-omap-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-spi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Ryan Barnett , Conrad Ratschan , Arnout Vandecappelle , Jean Pihet To: Mark Brown , Tony Lindgren , Vignesh Raghavendra Return-path: In-Reply-To: <20200114124125.361429-1-jean.pihet-OTs2U3NB0ngRmelmmXo44Q@public.gmane.org> Sender: linux-spi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Optimize the 8-bit based transfers, as used by the SPI flash devices, by reading the data registers by 32 and 128 bits when possible and copy the contents to the receive buffer. The speed improvement is 4.9x using quad read. Signed-off-by: Jean Pihet Cc: Ryan Barnett Cc: Conrad Ratschan Cc: Arnout Vandecappelle --- drivers/spi/spi-ti-qspi.c | 54 ++++++++++++++++++++++++++++++++++++--- 1 file changed, 51 insertions(+), 3 deletions(-) diff --git a/drivers/spi/spi-ti-qspi.c b/drivers/spi/spi-ti-qspi.c index 0334e2926998..858fda8ac73e 100644 --- a/drivers/spi/spi-ti-qspi.c +++ b/drivers/spi/spi-ti-qspi.c @@ -314,6 +314,8 @@ static int qspi_read_msg(struct ti_qspi *qspi, struct spi_transfer *t, { int wlen; unsigned int cmd; + u32 rx; + u8 rxlen, rx_wlen; u8 *rxbuf; rxbuf = t->rx_buf; @@ -336,14 +338,60 @@ static int qspi_read_msg(struct ti_qspi *qspi, struct spi_transfer *t, if (qspi_is_busy(qspi)) return -EBUSY; + switch (wlen) { + case 1: + /* + * Optimize the 8-bit words transfers, as used by + * the SPI flash devices. + */ + if (count >= QSPI_WLEN_MAX_BYTES) { + rxlen = QSPI_WLEN_MAX_BYTES; + } else { + rxlen = min(count, 4); + } + rx_wlen = rxlen << 3; + cmd &= ~QSPI_WLEN_MASK; + cmd |= QSPI_WLEN(rx_wlen); + break; + default: + rxlen = wlen; + break; + } + ti_qspi_write(qspi, cmd, QSPI_SPI_CMD_REG); if (ti_qspi_poll_wc(qspi)) { dev_err(qspi->dev, "read timed out\n"); return -ETIMEDOUT; } + switch (wlen) { case 1: - *rxbuf = readb(qspi->base + QSPI_SPI_DATA_REG); + /* + * Optimize the 8-bit words transfers, as used by + * the SPI flash devices. + */ + if (count >= QSPI_WLEN_MAX_BYTES) { + u32 *rxp = (u32 *) rxbuf; + rx = readl(qspi->base + QSPI_SPI_DATA_REG_3); + *rxp++ = be32_to_cpu(rx); + rx = readl(qspi->base + QSPI_SPI_DATA_REG_2); + *rxp++ = be32_to_cpu(rx); + rx = readl(qspi->base + QSPI_SPI_DATA_REG_1); + *rxp++ = be32_to_cpu(rx); + rx = readl(qspi->base + QSPI_SPI_DATA_REG); + *rxp++ = be32_to_cpu(rx); + } else { + u8 *rxp = rxbuf; + rx = readl(qspi->base + QSPI_SPI_DATA_REG); + if (rx_wlen >= 8) + *rxp++ = rx >> (rx_wlen - 8); + if (rx_wlen >= 16) + *rxp++ = rx >> (rx_wlen - 16); + if (rx_wlen >= 24) + *rxp++ = rx >> (rx_wlen - 24); + if (rx_wlen >= 32) + *rxp++ = rx; + } break; case 2: *((u16 *)rxbuf) = readw(qspi->base + QSPI_SPI_DATA_REG); @@ -352,8 +400,8 @@ static int qspi_read_msg(struct ti_qspi *qspi, struct spi_transfer *t, *((u32 *)rxbuf) = readl(qspi->base + QSPI_SPI_DATA_REG); break; } - rxbuf += wlen; - count -= wlen; + rxbuf += rxlen; + count -= rxlen; } return 0; -- 2.24.1