[PATCH] mmc: bcm2835_sdhci: Parse generic MMC device tree properties

Liel at denx.de Liel at denx.de
Sat May 9 23:06:07 CEST 2026


From: Liel Harel <liel.harel at gmail.com>

The bcm2835 SDHCI driver sets up the MMC host configuration via
sdhci_setup_cfg(), but does not parse generic MMC device tree
properties.

As a result, properties such as bus-width are ignored. On Raspberry Pi
Compute Module 4, the eMMC node describes an 8-bit bus, but U-Boot
initialized the device as 4-bit.

Call mmc_of_parse() before sdhci_setup_cfg() so that generic MMC
properties are folded into the host configuration before the MMC core
selects the bus width.

Before this change, mmc info reported:

    Bus Speed: 52000000
    Bus Width: 4-bit

After this change, mmc info reports:

    Bus Speed: 52000000
    Bus Width: 8-bit

Tested on Raspberry Pi Compute Module 4 with onboard eMMC.

Signed-off-by: Liel Harel <liel.harel at gmail.com>
---
 drivers/mmc/bcm2835_sdhci.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/mmc/bcm2835_sdhci.c b/drivers/mmc/bcm2835_sdhci.c
index 655d9902dfa..efa4d14f5da 100644
--- a/drivers/mmc/bcm2835_sdhci.c
+++ b/drivers/mmc/bcm2835_sdhci.c
@@ -219,6 +219,10 @@ static int bcm2835_sdhci_probe(struct udevice *dev)
 	host->mmc = &plat->mmc;
 	host->mmc->dev = dev;
 
+	ret = mmc_of_parse(dev, &plat->cfg);
+	if (ret)
+		return ret;
+
 	ret = sdhci_setup_cfg(&plat->cfg, host, emmc_freq, MIN_FREQ);
 	if (ret) {
 		debug("%s: Failed to setup SDHCI (err=%d)\n", __func__, ret);
-- 
2.43.0



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