From 46938abd2c4c2b605c5af9483fff20ef6772eafc Mon Sep 17 00:00:00 2001 From: Bin Meng Date: Tue, 2 Feb 2021 10:48:48 +0800 Subject: [PATCH] mmc: mmc_spi: Document the 3 local functions mmc_spi_sendcmd(), mmc_spi_readdata() and mmc_spi_writedata() are currently undocumented. Add comment blocks to explain the arguments and the return value. Signed-off-by: Bin Meng Reviewed-by: Jaehoon Chung --- drivers/mmc/mmc_spi.c | 36 +++++++++++++++++++++++++++++++++++- 1 file changed, 35 insertions(+), 1 deletion(-) diff --git a/drivers/mmc/mmc_spi.c b/drivers/mmc/mmc_spi.c index fbdbcf73ff..e2d78794f2 100644 --- a/drivers/mmc/mmc_spi.c +++ b/drivers/mmc/mmc_spi.c @@ -37,7 +37,8 @@ #define SPI_RESPONSE_CRC_ERR ((5 << 1)|1) #define SPI_RESPONSE_WRITE_ERR ((6 << 1)|1) -/* Read and write blocks start with these tokens and end with crc; +/* + * Read and write blocks start with these tokens and end with crc; * on error, read tokens act like a subset of R2_SPI_* values. */ /* single block write multiblock read */ @@ -70,6 +71,20 @@ struct mmc_spi_priv { struct spi_slave *spi; }; +/** + * mmc_spi_sendcmd() - send a command to the SD card + * + * @dev: mmc_spi device + * @cmdidx: command index + * @cmdarg: command argument + * @resp_type: card response type + * @resp: buffer to store the card response + * @resp_size: size of the card response + * @resp_match: if true, compare each of received bytes with @resp_match_value + * @resp_match_value: a value to be compared with each of received bytes + * @r1b: if true, receive additional bytes for busy signal token + * @return 0 if OK, -ETIMEDOUT if no card response is received, -ve on error + */ static int mmc_spi_sendcmd(struct udevice *dev, ushort cmdidx, u32 cmdarg, u32 resp_type, u8 *resp, u32 resp_size, @@ -159,6 +174,15 @@ static int mmc_spi_sendcmd(struct udevice *dev, return 0; } +/** + * mmc_spi_readdata() - read data block(s) from the SD card + * + * @dev: mmc_spi device + * @xbuf: buffer of the actual data (excluding token and crc) to read + * @bcnt: number of data blocks to transfer + * @bsize: size of the actual data (excluding token and crc) in bytes + * @return 0 if OK, -ECOMM if crc error, -ETIMEDOUT on other errors + */ static int mmc_spi_readdata(struct udevice *dev, void *xbuf, u32 bcnt, u32 bsize) { @@ -207,6 +231,16 @@ static int mmc_spi_readdata(struct udevice *dev, return ret; } +/** + * mmc_spi_writedata() - write data block(s) to the SD card + * + * @dev: mmc_spi device + * @xbuf: buffer of the actual data (excluding token and crc) to write + * @bcnt: number of data blocks to transfer + * @bsize: size of actual data (excluding token and crc) in bytes + * @multi: indicate a transfer by multiple block write command (CMD25) + * @return 0 if OK, -ECOMM if crc error, -ETIMEDOUT on other errors + */ static int mmc_spi_writedata(struct udevice *dev, const void *xbuf, u32 bcnt, u32 bsize, int multi) {