[U-Boot] [PATCH v3] driver: spi: fsl-qspi: disable AHB buffer prefetch

From: Yunhui Cui yunhui.cui@nxp.com

Errata: A-009282: QuadSPI data pre-fetch can result in incorrect data We need this errata workaround when CONFIG_SYS_FSL_QSPI_AHB is enabled.

Signed-off-by: Yunhui Cui yunhui.cui@nxp.com --- drivers/spi/fsl_qspi.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/spi/fsl_qspi.c b/drivers/spi/fsl_qspi.c index 75cbab2..0354e20 100644 --- a/drivers/spi/fsl_qspi.c +++ b/drivers/spi/fsl_qspi.c @@ -438,13 +438,23 @@ static void qspi_enable_ddr_mode(struct fsl_qspi_priv *priv) static void qspi_init_ahb_read(struct fsl_qspi_priv *priv) { struct fsl_qspi_regs *regs = priv->regs; + int rx_size = 0x80;

/* AHB configuration for access buffer 0/1/2 .*/ qspi_write32(priv->flags, &regs->buf0cr, QSPI_BUFXCR_INVALID_MSTRID); qspi_write32(priv->flags, &regs->buf1cr, QSPI_BUFXCR_INVALID_MSTRID); qspi_write32(priv->flags, &regs->buf2cr, QSPI_BUFXCR_INVALID_MSTRID); + +#ifdef CONFIG_SYS_FSL_ERRATUM_A009282 + /*A-009282: QuadSPI data pre-fetch can result in incorrect data + *Workaround: Keep the read data size to 64 bits (8 Bytes), which + *disables the prefetch on the AHB buffer,and prevents this issue + *from occurring. + */ + rx_size = 0x1; +#endif qspi_write32(priv->flags, &regs->buf3cr, QSPI_BUF3CR_ALLMST_MASK | - (0x80 << QSPI_BUF3CR_ADATSZ_SHIFT)); + (rx_size << QSPI_BUF3CR_ADATSZ_SHIFT));

/* We only use the buffer3 */ qspi_write32(priv->flags, &regs->buf0ind, 0);