dm: mmc: dwmmc: Add comments to the dwmmc setup functions

These comments were missed when the original code was written. Add them to
help people port their drivers over.

Signed-off-by: Simon Glass <sjg@chromium.org>

include/dwmmc.h

@@ -224,9 +224,73 @@ static inline u8 dwmci_readb(struct dwmci_host *host, int reg)
 	return readb(host->ioaddr + reg);
 }
 
+#ifdef CONFIG_BLK
+/**
+ * dwmci_setup_cfg() - Set up the configuration for DWMMC
+ *
+ * This is used to set up a DWMMC device when you are using CONFIG_BLK.
+ *
+ * This should be called from your MMC driver's probe() method once you have
+ * the information required.
+ *
+ * Generally your driver will have a platform data structure which holds both
+ * the configuration (struct mmc_config) and the MMC device info (struct mmc).
+ * For example:
+ *
+ * struct rockchip_mmc_plat {
+ *	struct mmc_config cfg;
+ *	struct mmc mmc;
+ * };
+ *
+ * ...
+ *
+ * Inside U_BOOT_DRIVER():
+ *	.platdata_auto_alloc_size = sizeof(struct rockchip_mmc_plat),
+ *
+ * To access platform data:
+ *	struct rockchip_mmc_plat *plat = dev_get_platdata(dev);
+ *
+ * See rockchip_dw_mmc.c for an example.
+ *
+ * @cfg:	Configuration structure to fill in (generally &plat->mmc)
+ * @name:	Device name (normally dev->name)
+ * @buswidth:	Bus width (in bits, such as 4 or 8)
+ * @caps:	Host capabilities (MMC_MODE_...)
+ * @max_clk:	Maximum supported clock speed in HZ (e.g. 400000)
+ * @min_clk:	Minimum supported clock speed in HZ (e.g. 150000000)
+ */
 void dwmci_setup_cfg(struct mmc_config *cfg, const char *name, int buswidth,
 		     uint caps, u32 max_clk, u32 min_clk);
+
+/**
+ * dwmci_bind() - Set up a new MMC block device
+ *
+ * This is used to set up a DWMMC block device when you are using CONFIG_BLK.
+ * It should be called from your driver's bind() method.
+ *
+ * See rockchip_dw_mmc.c for an example.
+ *
+ * @dev:	Device to set up
+ * @mmc:	Pointer to mmc structure (normally &plat->mmc)
+ * @cfg:	Empty configuration structure (generally &plat->cfg). This is
+ *		normally all zeroes at this point. The only purpose of passing
+ *		this in is to set mmc->cfg to it.
+ * @return 0 if OK, -ve if the block device could not be created
+ */
 int dwmci_bind(struct udevice *dev, struct mmc *mmc, struct mmc_config *cfg);
 
+#else
+/**
+ * add_dwmci() - Add a new DWMMC interface
+ *
+ * This is used when you are not using CONFIG_BLK. Convert your driver over!
+ *
+ * @host:	DWMMC host structure
+ * @max_clk:	Maximum supported clock speed in HZ (e.g. 400000)
+ * @min_clk:	Minimum supported clock speed in HZ (e.g. 150000000)
+ * @return 0 if OK, -ve on error
+ */
 int add_dwmci(struct dwmci_host *host, u32 max_clk, u32 min_clk);
+#endif /* !CONFIG_BLK */
+
 #endif	/* __DWMMC_HW_H */