Hi Kalle, On Wed, Apr 28, 2010 at 12:18 AM, Grazvydas Ignotas <notasas@xxxxxxxxx> wrote: > SDIO specification allows RAW (Read after Write) operation using > IO_RW_DIRECT command (CMD52) by setting the RAW bit. This operation is > similar to ordinary read/write commands, except that both write and read > are performed using single command/response pair. The Linux SDIO layer > already supports this internaly, only external function is missing for > drivers to make use, which is added by this patch. > > This type of command is required to implement proper power save mode > support in wl1251 wifi driver. As wl1251 maintainer, can you confirm this is needed for wl1251 driver to function in SDIO mode? Perhaps this could help convince Andrew to merge this patch. Without this the chip is having problems leaving ELP mode. Android has similar patch for G1 in it's tree for the same reason: http://android.git.kernel.org/?p=kernel/common.git;a=commitdiff;h=74a47786f6ecbe6c1cf9fb15efe6a968451deb52 > > Signed-off-by: Grazvydas Ignotas <notasas@xxxxxxxxx> > --- > drivers/mmc/core/sdio_io.c | 31 +++++++++++++++++++++++++++++++ > include/linux/mmc/sdio_func.h | 3 +++ > 2 files changed, 34 insertions(+), 0 deletions(-) > > diff --git a/drivers/mmc/core/sdio_io.c b/drivers/mmc/core/sdio_io.c > index ff27c8c..3f681be 100644 > --- a/drivers/mmc/core/sdio_io.c > +++ b/drivers/mmc/core/sdio_io.c > @@ -406,6 +406,37 @@ 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 > + * @b: 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 b, > + unsigned int addr, int *err_ret) > +{ > + int ret; > + u8 val; > + > + BUG_ON(!func); > + > + ret = mmc_io_rw_direct(func->card, 1, func->num, addr, b, &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 > diff --git a/include/linux/mmc/sdio_func.h b/include/linux/mmc/sdio_func.h > index c6c0cce..8974b19 100644 > --- a/include/linux/mmc/sdio_func.h > +++ b/include/linux/mmc/sdio_func.h > @@ -145,6 +145,9 @@ extern void sdio_writew(struct sdio_func *func, u16 b, > extern void sdio_writel(struct sdio_func *func, u32 b, > unsigned int addr, int *err_ret); > > +extern u8 sdio_writeb_readb(struct sdio_func *func, u8 b, > + unsigned int addr, int *err_ret); > + > extern int sdio_memcpy_toio(struct sdio_func *func, unsigned int addr, > void *src, int count); > extern int sdio_writesb(struct sdio_func *func, unsigned int addr, > -- > 1.6.3.3 > > -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
