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driver/mmcsd: add option to support SD/MMC PHYs that only run in 4-bit mode

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Richard Tucker 2022-03-24 14:56:40 +11:00 • committed by Xiang Xiao
parent d557b87b25
commit 163e3fd93c
2 changed files with 25 additions and 5 deletions
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29
drivers/mmcsd/mmcsd_sdio.c
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@ -2881,6 +2881,22 @@ static int mmcsd_sdinitialize(FAR struct mmcsd_state_s *priv)
SDIO_CLOCK(priv->dev, CLOCK_SD_TRANSFER_1BIT);
nxsig_usleep(MMCSD_CLK_DELAY);
/* If the hardware only supports 4-bit transfer mode then we forced to
* attempt to setup the card in this mode before checking the SCR register.
*/
if ((priv->caps & SDIO_CAPS_4BIT_ONLY) != 0)
{
/* Select width (4-bit) bus operation */
priv->buswidth = 4;
ret = mmcsd_widebus(priv);
if (ret != OK)
{
ferr("ERROR: Failed to set wide bus operation: %d\n", ret);
}
}
/* Get the SD card Configuration Register (SCR). We need this now because
* that configuration register contains the indication whether or not
* this card supports wide bus operation.
@ -2895,12 +2911,15 @@ static int mmcsd_sdinitialize(FAR struct mmcsd_state_s *priv)
mmcsd_decode_scr(priv, scr);
/* Select width (4-bit) bus operation (if the card supports it) */
ret = mmcsd_widebus(priv);
if (ret != OK)
if ((priv->caps & SDIO_CAPS_4BIT_ONLY) == 0)
{
ferr("ERROR: Failed to set wide bus operation: %d\n", ret);
/* Select width (4-bit) bus operation (if the card supports it) */
ret = mmcsd_widebus(priv);
if (ret != OK)
{
ferr("ERROR: Failed to set wide bus operation: %d\n", ret);
}
}
/* TODO: If wide-bus selected, then send CMD6 to see if the card supports

1
include/nuttx/sdio.h
View file

@ -477,6 +477,7 @@
#define SDIO_CAPS_DMABEFOREWRITE 0x04 /* Bit 2=1: Executes DMA before write command */
#define SDIO_CAPS_4BIT 0x08 /* Bit 3=1: Supports 4 bit operation */
#define SDIO_CAPS_8BIT 0x10 /* Bit 4=1: Supports 8 bit operation */
#define SDIO_CAPS_4BIT_ONLY 0x20 /* Bit 5=1: Supports 4-bit only operation */
/****************************************************************************
* Name: SDIO_STATUS