diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/mmc/core/sdio_io.c | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/drivers/mmc/core/sdio_io.c b/drivers/mmc/core/sdio_io.c index 4ad06e57563..eb6c20935ce 100644 --- a/drivers/mmc/core/sdio_io.c +++ b/drivers/mmc/core/sdio_io.c @@ -11,6 +11,7 @@ #include <linux/mmc/host.h> #include <linux/mmc/card.h> +#include <linux/mmc/sdio.h> #include <linux/mmc/sdio_func.h> #include "sdio_ops.h" @@ -48,6 +49,98 @@ void sdio_release_host(struct sdio_func *func) EXPORT_SYMBOL_GPL(sdio_release_host); /** + * sdio_enable_func - enables a SDIO function for usage + * @func: SDIO function to enable + * + * Powers up and activates a SDIO function so that register + * access is possible. + */ +int sdio_enable_func(struct sdio_func *func) +{ + int ret; + unsigned char reg; + unsigned long timeout; + + BUG_ON(!func); + BUG_ON(!func->card); + + pr_debug("SDIO: Enabling device %s...\n", sdio_func_id(func)); + + ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IOEx, 0, ®); + if (ret) + goto err; + + reg |= 1 << func->num; + + ret = mmc_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IOEx, reg, NULL); + if (ret) + goto err; + + /* + * FIXME: This should timeout based on information in the CIS, + * but we don't have card to parse that yet. + */ + timeout = jiffies + HZ; + + while (1) { + ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IORx, 0, ®); + if (ret) + goto err; + if (reg & (1 << func->num)) + break; + ret = -ETIME; + if (time_after(jiffies, timeout)) + goto err; + } + + pr_debug("SDIO: Enabled device %s\n", sdio_func_id(func)); + + return 0; + +err: + pr_debug("SDIO: Failed to enable device %s\n", sdio_func_id(func)); + return ret; +} +EXPORT_SYMBOL_GPL(sdio_enable_func); + +/** + * sdio_disable_func - disable a SDIO function + * @func: SDIO function to disable + * + * Powers down and deactivates a SDIO function. Register access + * to this function will fail until the function is reenabled. + */ +int sdio_disable_func(struct sdio_func *func) +{ + int ret; + unsigned char reg; + + BUG_ON(!func); + BUG_ON(!func->card); + + pr_debug("SDIO: Disabling device %s...\n", sdio_func_id(func)); + + ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IOEx, 0, ®); + if (ret) + goto err; + + reg &= ~(1 << func->num); + + ret = mmc_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IOEx, reg, NULL); + if (ret) + goto err; + + pr_debug("SDIO: Disabled device %s\n", sdio_func_id(func)); + + return 0; + +err: + pr_debug("SDIO: Failed to disable device %s\n", sdio_func_id(func)); + return -EIO; +} +EXPORT_SYMBOL_GPL(sdio_disable_func); + +/** * sdio_readb - read a single byte from a SDIO function * @func: SDIO function to access * @addr: address to read |