diff --git a/drivers/spi/spi-rspi.c b/drivers/spi/spi-rspi.c index ea3f2680d3c1..38c0cd7febab 100644 --- a/drivers/spi/spi-rspi.c +++ b/drivers/spi/spi-rspi.c @@ -334,14 +334,26 @@ static int rspi_rz_set_config_register(struct rspi_data *rspi, int access_size) */ static int qspi_set_config_register(struct rspi_data *rspi, int access_size) { - int spbr; + unsigned long clksrc; + int brdv = 0, spbr; /* Sets output mode, MOSI signal, and (optionally) loopback */ rspi_write8(rspi, rspi->sppcr, RSPI_SPPCR); /* Sets transfer bit rate */ - spbr = DIV_ROUND_UP(clk_get_rate(rspi->clk), 2 * rspi->speed_hz); - rspi_write8(rspi, clamp(spbr, 0, 255), RSPI_SPBR); + clksrc = clk_get_rate(rspi->clk); + if (rspi->speed_hz >= clksrc) { + spbr = 0; + } else { + spbr = DIV_ROUND_UP(clksrc, 2 * rspi->speed_hz); + while (spbr > 255 && brdv < 3) { + brdv++; + spbr = DIV_ROUND_UP(spbr, 2); + } + spbr = clamp(spbr, 0, 255); + } + rspi_write8(rspi, spbr, RSPI_SPBR); + rspi->spcmd |= SPCMD_BRDV(brdv); /* Disable dummy transmission, set byte access */ rspi_write8(rspi, 0, RSPI_SPDCR);