From: Michael Walle Date: Thu, 18 Jul 2024 20:42:52 +0000 (+0200) Subject: spi: sunxi: fix CDR2 calculation X-Git-Url: http://git.dujemihanovic.xyz/html/static/%7B%7B%20.Permalink%20%7D%7D?a=commitdiff_plain;h=6aadcb814d1e2203b0b953dda8d5fbdc7b3a9bf0;p=u-boot.git spi: sunxi: fix CDR2 calculation The CDR2 divider calculation always yield a frequency greater than the requested one. Use DIV_ROUND_UP() to keep the frequency equal or below the requested one. This way, we can also drop the "if div > 0" check because we know for a fact that div cannot be zero. FWIW, this aligns the CDR2 calculation with the linux driver. Suggested-by: Andre Przywara Signed-off-by: Michael Walle Reviewed-by: Andre Przywara --- diff --git a/drivers/spi/spi-sunxi.c b/drivers/spi/spi-sunxi.c index a7333d8d9c..cbc2c4c7b4 100644 --- a/drivers/spi/spi-sunxi.c +++ b/drivers/spi/spi-sunxi.c @@ -233,7 +233,7 @@ err_ahb: static void sun4i_spi_set_speed_mode(struct udevice *dev) { struct sun4i_spi_priv *priv = dev_get_priv(dev); - unsigned int div; + unsigned int div, div_cdr2; u32 reg; /* @@ -259,15 +259,12 @@ static void sun4i_spi_set_speed_mode(struct udevice *dev) */ div = DIV_ROUND_UP(SUNXI_INPUT_CLOCK, priv->freq); + div_cdr2 = DIV_ROUND_UP(div, 2); reg = readl(SPI_REG(priv, SPI_CCR)); - if ((div / 2) <= (SUN4I_CLK_CTL_CDR2_MASK + 1)) { - div /= 2; - if (div > 0) - div--; - + if (div_cdr2 <= (SUN4I_CLK_CTL_CDR2_MASK + 1)) { reg &= ~(SUN4I_CLK_CTL_CDR2_MASK | SUN4I_CLK_CTL_DRS); - reg |= SUN4I_CLK_CTL_CDR2(div) | SUN4I_CLK_CTL_DRS; + reg |= SUN4I_CLK_CTL_CDR2(div_cdr2 - 1) | SUN4I_CLK_CTL_DRS; } else { div = fls(div - 1); /* The F1C100s encodes the divider as 2^(n+1) */