diff options
| author | Bin Meng | 2021-02-02 10:48:48 +0800 |
|---|---|---|
| committer | Peng Fan | 2021-02-19 15:08:03 +0800 |
| commit | 46938abd2c4c2b605c5af9483fff20ef6772eafc (patch) | |
| tree | a959c91719ef94c571a4480cc4c22f9939cb0b8e /drivers/mmc | |
| parent | 2f22cb40e57f28b694c05c0b631cbb0c09eb03a4 (diff) | |
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 <bin.meng@windriver.com>
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>
Diffstat (limited to 'drivers/mmc')
| -rw-r--r-- | drivers/mmc/mmc_spi.c | 36 |
1 files changed, 35 insertions, 1 deletions
diff --git a/drivers/mmc/mmc_spi.c b/drivers/mmc/mmc_spi.c index fbdbcf73ff4..e2d78794f2a 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) { |