@@ -93,28 +93,39 @@ struct mmc_host_ops {
void (*pre_req)(struct mmc_host *host, struct mmc_request *req,
bool is_first_req);
void (*request)(struct mmc_host *host, struct mmc_request *req);
+
+ /*
+ * Avoid calling the next three functions too often or in a "fast
+ * path", since underlaying controller might implement them in an
+ * expensive and/or slow way. Also note that these functions might
+ * sleep, so don't call them in the atomic contexts!
+ */
+
+ /*
+ * Notes to the set_ios callback:
+ * ios->clock might be 0. For some controllers, setting 0Hz
+ * as any other frequency works. However, some controllers
+ * explicitly need to disable the clock. Otherwise e.g. voltage
+ * switching might fail because the SDCLK is not really quiet.
+ */
+ void (*set_ios)(struct mmc_host *host, struct mmc_ios *ios);
+
/*
- * Avoid calling these three functions too often or in a "fast path",
- * since underlaying controller might implement them in an expensive
- * and/or slow way.
- *
- * Also note that these functions might sleep, so don't call them
- * in the atomic contexts!
- *
* Return values for the get_ro callback should be:
* 0 for a read/write card
* 1 for a read-only card
* -ENOSYS when not supported (equal to NULL callback)
* or a negative errno value when something bad happened
- *
+ */
+ int (*get_ro)(struct mmc_host *host);
+
+ /*
* Return values for the get_cd callback should be:
* 0 for a absent card
* 1 for a present card
* -ENOSYS when not supported (equal to NULL callback)
* or a negative errno value when something bad happened
*/
- void (*set_ios)(struct mmc_host *host, struct mmc_ios *ios);
- int (*get_ro)(struct mmc_host *host);
int (*get_cd)(struct mmc_host *host);
void (*enable_sdio_irq)(struct mmc_host *host, int enable);