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-rw-r--r--drivers/mmc/core/sdio_io.c93
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, &reg);
+ 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, &reg);
+ 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, &reg);
+ 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