[U-Boot] [PATCH v2 27/29] dm: ahci: Add a driver for SCSI on AHCI

[Simon Glass]

Some AHCI drivers use SCSI under the hood. Rather than making the AHCI
driver be in the SCSI uclass it makes sense to have the AHCI device create
a SCSI device as a child. That way we can handle any AHCI-specific
operations rather than trying to pretend tha the device is just SCSI.

To handle this we need to provide a way for AHCI drivers to bind a SCSI
device as its child, and probe it. Add functions for this.

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

Changes in v2:
- Make it clear that non-PCI AHCI is not yet supported

 drivers/ata/ahci.c | 57 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 include/ahci.h     | 22 +++++++++++++++++++++
 2 files changed, 79 insertions(+)

diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index 3528a1f3da..6da412d178 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -19,10 +19,13 @@
 #include <asm/io.h>
 #include <malloc.h>
 #include <memalign.h>
+#include <pci.h>
 #include <scsi.h>
 #include <libata.h>
 #include <linux/ctype.h>
 #include <ahci.h>
+#include <dm/device-internal.h>
+#include <dm/lists.h>
 
 static int ata_io_flush(struct ahci_uc_priv *uc_priv, u8 port);
 
@@ -1142,10 +1145,64 @@ static int ahci_scsi_bus_reset(struct udevice *dev)
 }
 
 #ifdef CONFIG_DM_SCSI
+int ahci_bind_scsi(struct udevice *ahci_dev, struct udevice **devp)
+{
+	struct udevice *dev;
+	int ret;
+
+	ret = device_bind_driver(ahci_dev, "ahci_scsi", "ahci_scsi", &dev);
+	if (ret)
+		return ret;
+	*devp = dev;
+
+	return 0;
+}
+
+int ahci_probe_scsi(struct udevice *ahci_dev)
+{
+#ifdef CONFIG_SCSI_AHCI_PLAT
+	return -ENOSYS;  /* TODO(sjg at chromium.org): Support non-PCI AHCI */
+#else
+	struct ahci_uc_priv *uc_priv;
+	struct scsi_platdata *uc_plat;
+	struct udevice *dev;
+	int ret;
+
+	device_find_first_child(ahci_dev, &dev);
+	if (!dev)
+		return -ENODEV;
+	uc_plat = dev_get_uclass_platdata(dev);
+	uc_plat->base = (ulong)dm_pci_map_bar(ahci_dev, PCI_BASE_ADDRESS_5,
+					      PCI_REGION_MEM);
+	uc_plat->max_lun = 1;
+	uc_plat->max_id = 2;
+	uc_priv = dev_get_uclass_priv(dev);
+	ret = ahci_init_one(uc_priv, dev);
+	if (ret)
+		return ret;
+	ret = ahci_start_ports(uc_priv);
+	if (ret)
+		return ret;
+
+	debug("Scanning %s\n", dev->name);
+	ret = scsi_scan_dev(dev, true);
+	if (ret)
+		return ret;
+#endif
+
+	return 0;
+}
+
 struct scsi_ops scsi_ops = {
 	.exec		= ahci_scsi_exec,
 	.bus_reset	= ahci_scsi_bus_reset,
 };
+
+U_BOOT_DRIVER(ahci_scsi) = {
+	.name		= "ahci_scsi",
+	.id		= UCLASS_SCSI,
+	.ops		= &scsi_ops,
+};
 #else
 int scsi_exec(struct udevice *dev, struct scsi_cmd *pccb)
 {
diff --git a/include/ahci.h b/include/ahci.h
index 3d61ad1fce..818f34464e 100644
--- a/include/ahci.h
+++ b/include/ahci.h
@@ -200,4 +200,26 @@ int achi_start_ports_dm(struct udevice *dev);
  */
 int ahci_init_dm(struct udevice *dev, void __iomem *base);
 
+/**
+ * ahci_bind_scsi() - bind a new SCSI bus as a child
+ *
+ * Note that the SCSI bus device will itself bind block devices
+ *
+ * @ahci_dev: AHCI parent device
+ * @devp: Returns new SCSI bus device
+ * @return 0 if OK, -ve on error
+ */
+int ahci_bind_scsi(struct udevice *ahci_dev, struct udevice **devp);
+
+/**
+ * ahci_probe_scsi() - probe and scan the attached SCSI bus
+ *
+ * Note that the SCSI device will itself bind block devices for any storage
+ * devices it finds.
+ *
+ * @ahci_dev: AHCI parent device
+ * @return 0 if OK, -ve on error
+ */
+int ahci_probe_scsi(struct udevice *ahci_dev);
+
 #endif
-- 
2.13.1.518.g3df882009-goog