dm: scsi: Add operations for SCSI devices

The SCSI uclass currently has no operations. It just uses the global SCSI
functions. Fix this by adding operations to the only two drivers that use
the uclass, and replacing the global functions with those defined locally
in the SCSI code.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

drivers/ata/ahci.c

@@ -1141,6 +1141,12 @@ static int ahci_scsi_bus_reset(struct udevice *dev)
 	return 0;
 }
 
+#ifdef CONFIG_DM_SCSI
+struct scsi_ops scsi_ops = {
+	.exec		= ahci_scsi_exec,
+	.bus_reset	= ahci_scsi_bus_reset,
+};
+#else
 int scsi_exec(struct udevice *dev, struct scsi_cmd *pccb)
 {
 	return ahci_scsi_exec(dev, pccb);
@@ -1152,3 +1158,4 @@ __weak int scsi_bus_reset(struct udevice *dev)
 
 	return 0;
 }
+#endif

drivers/ata/dwc_ahci.c

@@ -98,6 +98,7 @@ U_BOOT_DRIVER(dwc_ahci) = {
 	.id	= UCLASS_SCSI,
 	.of_match = dwc_ahci_ids,
 	.ofdata_to_platdata = dwc_ahci_ofdata_to_platdata,
+	.ops	= &scsi_ops,
 	.probe	= dwc_ahci_probe,
 	.priv_auto_alloc_size = sizeof(struct dwc_ahci_priv),
 	.flags = DM_FLAG_ALLOC_PRIV_DMA,

drivers/ata/sata_ceva.c

@@ -144,6 +144,7 @@ U_BOOT_DRIVER(ceva_host_blk) = {
 	.name = "ceva_sata",
 	.id = UCLASS_SCSI,
 	.of_match = sata_ceva_ids,
+	.ops = &scsi_ops,
 	.probe = sata_ceva_probe,
 	.ofdata_to_platdata = sata_ceva_ofdata_to_platdata,
 };

drivers/scsi/scsi-uclass.c

@@ -13,6 +13,26 @@
 #include <dm.h>
 #include <scsi.h>
 
+int scsi_exec(struct udevice *dev, struct scsi_cmd *pccb)
+{
+	struct scsi_ops *ops = scsi_get_ops(dev);
+
+	if (!ops->exec)
+		return -ENOSYS;
+
+	return ops->exec(dev, pccb);
+}
+
+int scsi_bus_reset(struct udevice *dev)
+{
+	struct scsi_ops *ops = scsi_get_ops(dev);
+
+	if (!ops->bus_reset)
+		return -ENOSYS;
+
+	return ops->bus_reset(dev);
+}
+
 UCLASS_DRIVER(scsi) = {
 	.id		= UCLASS_SCSI,
 	.name		= "scsi",

include/scsi.h

@@ -191,12 +191,25 @@ struct scsi_ops {
 	int (*bus_reset)(struct udevice *dev);
 };
 
-#ifndef CONFIG_DM_SCSI
-void scsi_low_level_init(int busdevfunc);
-void scsi_init(void);
-#endif
+#define scsi_get_ops(dev)        ((struct scsi_ops *)(dev)->driver->ops)
 
-int scsi_exec(struct udevice *dev, struct scsi_cmd *pccb);
+extern struct scsi_ops scsi_ops;
+
+/**
+ * scsi_exec() - execute a command
+ *
+ * @dev:	SCSI bus
+ * @cmd:	Command to execute
+ * @return 0 if OK, -ve on error
+ */
+int scsi_exec(struct udevice *dev, struct scsi_cmd *cmd);
+
+/**
+ * scsi_bus_reset() - reset the bus
+ *
+ * @dev:	SCSI bus to reset
+ * @return 0 if OK, -ve on error
+ */
 int scsi_bus_reset(struct udevice *dev);
 
 /**
@@ -206,6 +219,11 @@ int scsi_bus_reset(struct udevice *dev);
  */
 int scsi_scan(bool verbose);
 
+#ifndef CONFIG_DM_SCSI
+void scsi_low_level_init(int busdevfunc);
+void scsi_init(void);
+#endif
+
 #define SCSI_IDENTIFY					0xC0  /* not used */
 
 /* Hardware errors  */