diff options
| author | Sarthak Garg <quic_sartgarg@quicinc.com> | 2025-09-08 16:11:21 +0530 |
|---|---|---|
| committer | Ulf Hansson <ulf.hansson@linaro.org> | 2025-09-12 14:49:36 +0200 |
| commit | f338529ca9279e3bea392cb53cec8bd292909cb1 (patch) | |
| tree | 26adc71748b4c165012bee04a348a362fbe1694d | |
| parent | 98682689a1a443067e1981d9eed8c6ddcef8cdf3 (diff) | |
mmc: core: Parse and use the new max-sd-hs-hz DT property
Introduce a new device tree flag to cap the maximum High-Speed (HS)
mode frequency for SD cards, accommodating board-specific
electrical limitations which cannot support the default 50Mhz HS
frequency and others.
Signed-off-by: Sarthak Garg <quic_sartgarg@quicinc.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
| -rw-r--r-- | drivers/mmc/core/host.c | 2 | ||||
| -rw-r--r-- | drivers/mmc/core/sd.c | 2 | ||||
| -rw-r--r-- | include/linux/mmc/host.h | 1 |
3 files changed, 4 insertions, 1 deletions
diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c index 5f0ec23aeff5..88c95dbfd9cf 100644 --- a/drivers/mmc/core/host.c +++ b/drivers/mmc/core/host.c @@ -302,6 +302,8 @@ int mmc_of_parse(struct mmc_host *host) /* f_max is obtained from the optional "max-frequency" property */ device_property_read_u32(dev, "max-frequency", &host->f_max); + device_property_read_u32(dev, "max-sd-hs-hz", &host->max_sd_hs_hz); + /* * Configure CD and WP pins. They are both by default active low to * match the SDHCI spec. If GPIOs are provided for CD and / or WP, the diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c index ec02067f03c5..67cd63004829 100644 --- a/drivers/mmc/core/sd.c +++ b/drivers/mmc/core/sd.c @@ -359,7 +359,7 @@ static int mmc_read_switch(struct mmc_card *card) } if (status[13] & SD_MODE_HIGH_SPEED) - card->sw_caps.hs_max_dtr = HIGH_SPEED_MAX_DTR; + card->sw_caps.hs_max_dtr = card->host->max_sd_hs_hz ?: HIGH_SPEED_MAX_DTR; if (card->scr.sda_spec3) { card->sw_caps.sd3_bus_mode = status[13]; diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h index e0d935a4ac1d..e0e2c265e5d1 100644 --- a/include/linux/mmc/host.h +++ b/include/linux/mmc/host.h @@ -576,6 +576,7 @@ struct mmc_host { int hsq_depth; u32 err_stats[MMC_ERR_MAX]; + u32 max_sd_hs_hz; unsigned long private[] ____cacheline_aligned; }; |