diff options
Diffstat (limited to 'drivers/mmc/core/sdio_io.c')
| -rw-r--r-- | drivers/mmc/core/sdio_io.c | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/drivers/mmc/core/sdio_io.c b/drivers/mmc/core/sdio_io.c index ff27c8c71355..0f687cdeb064 100644 --- a/drivers/mmc/core/sdio_io.c +++ b/drivers/mmc/core/sdio_io.c @@ -406,6 +406,36 @@ void sdio_writeb(struct sdio_func *func, u8 b, unsigned int addr, int *err_ret) EXPORT_SYMBOL_GPL(sdio_writeb); /** + * sdio_writeb_readb - write and read a byte from SDIO function + * @func: SDIO function to access + * @write_byte: byte to write + * @addr: address to write to + * @err_ret: optional status value from transfer + * + * Performs a RAW (Read after Write) operation as defined by SDIO spec - + * single byte is written to address space of a given SDIO function and + * response is read back from the same address, both using single request. + * If there is a problem with the operation, 0xff is returned and + * @err_ret will contain the error code. + */ +u8 sdio_writeb_readb(struct sdio_func *func, u8 write_byte, + unsigned int addr, int *err_ret) +{ + int ret; + u8 val; + + ret = mmc_io_rw_direct(func->card, 1, func->num, addr, + write_byte, &val); + if (err_ret) + *err_ret = ret; + if (ret) + val = 0xff; + + return val; +} +EXPORT_SYMBOL_GPL(sdio_writeb_readb); + +/** * sdio_memcpy_fromio - read a chunk of memory from a SDIO function * @func: SDIO function to access * @dst: buffer to store the data |