diff options
| author | Inochi Amaoto <inochiama@gmail.com> | 2026-05-21 15:21:20 +0800 |
|---|---|---|
| committer | Ulf Hansson <ulfh@kernel.org> | 2026-05-29 14:43:42 +0200 |
| commit | b837e38c255dd9f8b53511d52e87f1fda32b3dfe (patch) | |
| tree | 7b472ce963cd953b58666229cb4834115468fb3e | |
| parent | f48ee49726ee4ab545fd2dc644f169c0809b19b3 (diff) | |
mmc: litex_mmc: Use DIV_ROUND_UP for more accurate clock calculation
The previous clock uses roundup_pow_of_two() to calculate the core
clock frequency. It does not meet the actual hardware meaning.
The actual frequency is calculated by "ref_clk / ((div >> 1) << 1)".
Fix the clock divider calculation.
Fixes: 92e099104729 ("mmc: Add driver for LiteX's LiteSDCard interface")
Signed-off-by: Inochi Amaoto <inochiama@gmail.com>
Reviewed-by: Gabriel Somlo <gsomlo@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Ulf Hansson <ulfh@kernel.org>
| -rw-r--r-- | drivers/mmc/host/litex_mmc.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/mmc/host/litex_mmc.c b/drivers/mmc/host/litex_mmc.c index d2f19c2dc673..52571bb17c61 100644 --- a/drivers/mmc/host/litex_mmc.c +++ b/drivers/mmc/host/litex_mmc.c @@ -16,6 +16,7 @@ #include <linux/interrupt.h> #include <linux/iopoll.h> #include <linux/litex.h> +#include <linux/math.h> #include <linux/mod_devicetable.h> #include <linux/module.h> #include <linux/platform_device.h> @@ -436,11 +437,10 @@ static void litex_mmc_setclk(struct litex_mmc_host *host, unsigned int freq) struct device *dev = mmc_dev(host->mmc); u32 div; - div = freq ? host->ref_clk / freq : 256U; - div = roundup_pow_of_two(div); + div = freq ? DIV_ROUND_UP(host->ref_clk, freq) : 256U; div = clamp(div, 2U, 256U); dev_dbg(dev, "sd_clk_freq=%d: set to %d via div=%d\n", - freq, host->ref_clk / div, div); + freq, host->ref_clk / ((div + 1) & ~1U), div); litex_write16(host->sdphy + LITEX_PHY_CLOCKERDIV, div); host->sd_clk = freq; } |