diff options
| author | Michael Walle <mwalle@kernel.org> | 2024-07-18 22:42:52 +0200 |
|---|---|---|
| committer | Andre Przywara <andre.przywara@arm.com> | 2024-08-06 11:20:10 +0100 |
| commit | 6aadcb814d1e2203b0b953dda8d5fbdc7b3a9bf0 (patch) | |
| tree | 36bb9078d8d3022eae129e20305e080fa637b636 /drivers/spi/spi-sunxi.c | |
| parent | 895d051702790311a98244e26c757c12771022e2 (diff) | |
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 <andre.przywara@arm.com>
Signed-off-by: Michael Walle <mwalle@kernel.org>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Diffstat (limited to 'drivers/spi/spi-sunxi.c')
| -rw-r--r-- | drivers/spi/spi-sunxi.c | 11 |
1 files changed, 4 insertions, 7 deletions
diff --git a/drivers/spi/spi-sunxi.c b/drivers/spi/spi-sunxi.c index a7333d8d9c0..cbc2c4c7b42 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) */ |