mmc: fsl_esdhc: Set fallback mode to 1-bit

8-bit mode is not supported by SD cards and on P2020 are four SDHC pins
shared with SPI (so if P2020 board have also SPI then only 4-bit SDHC mode
is provided). So 8-bit SDHC mode is really bad default.

When max bus width is not provided then set mode to 1-bit. This mode is
supported by all cards, so it is the best option for fallback mode.

Also P2020 bootrom sets mode to 1-bit when booting from SD/MMC card.

Signed-off-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>

diff --git a/drivers/mmc/fsl_esdhc.c b/drivers/mmc/fsl_esdhc.c
index fdf2cc2..6c6d03d 100644 (file)
--- a/drivers/mmc/fsl_esdhc.c
+++ b/drivers/mmc/fsl_esdhc.c
@@ -946,9 +946,8 @@ int fsl_esdhc_initialize(struct bd_info *bis, struct fsl_esdhc_cfg *cfg)
        } else if (cfg->max_bus_width == 1) {
                mmc_cfg->host_caps |= MMC_MODE_1BIT;
        } else {
-               mmc_cfg->host_caps |= MMC_MODE_1BIT | MMC_MODE_4BIT |
-                                     MMC_MODE_8BIT;
-               printf("No max bus width provided. Assume 8-bit supported.\n");
+               mmc_cfg->host_caps |= MMC_MODE_1BIT;
+               printf("No max bus width provided. Fallback to 1-bit mode.\n");
        }
 
        if (IS_ENABLED(CONFIG_ESDHC_DETECT_8_BIT_QUIRK))