diff --git a/drivers/spi/spi-nxp-fspi.c b/drivers/spi/spi-nxp-fspi.c index 39c1eaaf9e0a..54355295f919 100644 --- a/drivers/spi/spi-nxp-fspi.c +++ b/drivers/spi/spi-nxp-fspi.c @@ -867,6 +867,7 @@ static void nxp_fspi_select_mem(struct nxp_fspi *f, struct spi_device *spi, unsigned long rate = op->max_freq; int ret; uint64_t size_kb; + u32 reg; /* * Return when following condition all meet, @@ -896,6 +897,15 @@ static void nxp_fspi_select_mem(struct nxp_fspi *f, struct spi_device *spi, dev_dbg(f->dev, "Target device [CS:%x] selected\n", spi_get_chipselect(spi, 0)); + /* + * Per the FlexSPI reference manual (initialization sequence), MCR0 and + * the DLL control registers should be configured while the module is in + * stop mode (MCR0[MDIS] = 1). Enter stop mode before reconfiguring the + * RX sample clock source and the DLL, then exit stop mode afterwards. + */ + reg = fspi_readl(f, f->iobase + FSPI_MCR0); + fspi_writel(f, reg | FSPI_MCR0_MDIS, f->iobase + FSPI_MCR0); + nxp_fspi_select_rx_sample_clk_source(f, op_is_dtr); rate = min(f->max_rate, op->max_freq); @@ -928,6 +938,10 @@ static void nxp_fspi_select_mem(struct nxp_fspi *f, struct spi_device *spi, else nxp_fspi_dll_override(f); + /* Exit stop mode now that MCR0 and the DLL have been reconfigured. */ + reg = fspi_readl(f, f->iobase + FSPI_MCR0); + fspi_writel(f, reg & ~FSPI_MCR0_MDIS, f->iobase + FSPI_MCR0); + f->pre_op_rate = op->max_freq; f->selected = spi_get_chipselect(spi, 0);