Hi Ryan, On Friday 26 July 2013 10:23:01 Ryan Mallon wrote: > On 26/07/13 10:04, Laurent Pinchart wrote: > > On Friday 26 July 2013 09:45:26 Ryan Mallon wrote: > >> On 26/07/13 09:26, Laurent Pinchart wrote: > >>> Add support for passing CD/RO GPIO numbers directly to the mmc_spi > >>> driver instead of relying solely on board code callbacks to retrieve the > >>> CD/RO signals values. > >>> > >>> Signed-off-by: Laurent Pinchart > >>> <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx> > >>> --- > >>> > >>> drivers/mmc/host/mmc_spi.c | 32 +++++++++++++++++++++--------- > >>> drivers/mmc/host/of_mmc_spi.c | 46 ++++++++++-------------------------- > >>> include/linux/spi/mmc_spi.h | 11 +++++++++++ > >>> 3 files changed, 46 insertions(+), 43 deletions(-) > >>> > >>> diff --git a/drivers/mmc/host/mmc_spi.c b/drivers/mmc/host/mmc_spi.c > >>> index 74145d1..4e83908 100644 > >>> --- a/drivers/mmc/host/mmc_spi.c > >>> +++ b/drivers/mmc/host/mmc_spi.c > >>> @@ -36,6 +36,7 @@ > >>> > >>> #include <linux/mmc/host.h> > >>> #include <linux/mmc/mmc.h> /* for R1_SPI_* bit values */ > >>> +#include <linux/mmc/slot-gpio.h> > >>> #include <linux/spi/spi.h> > >>> #include <linux/spi/mmc_spi.h> > >>> > >>> @@ -1278,11 +1279,8 @@ static int mmc_spi_get_ro(struct mmc_host *mmc) > >>> if (host->pdata && host->pdata->get_ro) > >>> return !!host->pdata->get_ro(mmc->parent); > >>> > >>> - /* > >>> - * Board doesn't support read only detection; let the mmc core > >>> - * decide what to do. > >>> - */ > >>> - return -ENOSYS; > >>> + else > >>> + return mmc_gpio_get_ro(mmc); > >> > >> Why not just have the board file assign mmc_gpio_get_ro as > >> host->pdata->get_ro? This would eliminate the need for the > >> MMC_SPI_USE_RO_GPIO flag. > > > > Because the idea is to get rid of board callbacks and rely on proper > > kernel abstraction layers such as the GPIO subsystem. This will be > > especially important when adding device tree support to the mmc_spi > > driver. > > > >> Also, if host->pdata->get_ro is not set then this will assume > >> mmc_gpio_get_ro is valid, even if MMC_SPI_USE_RO_GPIO is not set. I'm > >> guessing it will end up returning -ENOSYS, but they way the code reads is > >> that if the host doesn't have get_ro function set, then it is must be a > >> gpio. > > > > mmc_gpio_get_ro() will indeed return -ENOSYS when the MMC_SPI_USE_RO_GPIO > > flag isn't set, as the mmc_spi driver will not call mmc_gpio_request_ro() > > in that case. > > > > This patch hides the -ENOSYS value from the mmc_spi_get_ro() and > > mmc_spi_get_cd() functions, perhaps making them slightly confusing, but > > patch 06/12 then gets rid of those functions, so I don't think it's a bit > > issue. > > Ah, I didn't read far enough along in the patch series :-). So all mmc spi > ro/cd controls are now assumed to be gpios? That's correct. It's the case in practice for all the boards we support in mainline. If the situation changes in the future for a new board (hardware engineers tend to have strange design ideas sometimes) a custom GPIO driver might be needed (for FPGA/CPLD-controlled GPIOs for instance). -- Regards, Laurent Pinchart -- 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
