sandbox: pci: Remember the device being emulated

Add a field to the PCI emulator per-device data which records which device
is being emulated. This is useful when the emulator needs to check the
device for something.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>
[bmeng: rebase the patch against u-boot-x86/master to get it applied cleanly]
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>

2 files changed, 44 insertions, 6 deletions

diff --git a/drivers/pci/pci-emul-uclass.c b/drivers/pci/pci-emul-uclass.c
index 0dcf937d9a..0f63e491a7 100644
--- a/drivers/pci/pci-emul-uclass.c
+++ b/drivers/pci/pci-emul-uclass.c
@@ -18,6 +18,7 @@ struct sandbox_pci_emul_priv {
 int sandbox_pci_get_emul(struct udevice *bus, pci_dev_t find_devfn,
 			 struct udevice **containerp, struct udevice **emulp)
 {
+	struct pci_emul_uc_priv *upriv;
 	struct udevice *dev;
 	int ret;
 
@@ -30,16 +31,32 @@ int sandbox_pci_get_emul(struct udevice *bus, pci_dev_t find_devfn,
 	}
 	*containerp = dev;
 
-	/*
-	 * See commit 4345998ae9df,
-	 * "pci: sandbox: Support dynamically binding device driver"
-	 */
 	ret = uclass_get_device_by_phandle(UCLASS_PCI_EMUL, dev, "sandbox,emul",
 					   emulp);
-	if (ret && device_get_uclass_id(dev) != UCLASS_PCI_GENERIC)
+	if (!ret) {
+		upriv = dev_get_uclass_priv(*emulp);
+
+		upriv->client = dev;
+	} else if (device_get_uclass_id(dev) != UCLASS_PCI_GENERIC) {
+		/*
+		 * See commit 4345998ae9df,
+		 * "pci: sandbox: Support dynamically binding device driver"
+		 */
 		*emulp = dev;
+	}
+
+	return 0;
+}
 
-	return *emulp ? 0 : -ENODEV;
+int sandbox_pci_get_client(struct udevice *emul, struct udevice **devp)
+{
+	struct pci_emul_uc_priv *upriv = dev_get_uclass_priv(emul);
+
+	if (!upriv->client)
+		return -ENOENT;
+	*devp = upriv->client;
+
+	return 0;
 }
 
 uint sandbox_pci_read_bar(u32 barval, int type, uint size)
@@ -88,6 +105,7 @@ UCLASS_DRIVER(pci_emul) = {
 	.post_probe	= sandbox_pci_emul_post_probe,
 	.pre_remove	= sandbox_pci_emul_pre_remove,
 	.priv_auto_alloc_size	= sizeof(struct sandbox_pci_emul_priv),
+	.per_device_auto_alloc_size	= sizeof(struct pci_emul_uc_priv),
 };
 
 /*
diff --git a/include/pci.h b/include/pci.h
index 8aa6636cfb..ff59ac0e69 100644
--- a/include/pci.h
+++ b/include/pci.h
@@ -1491,6 +1491,17 @@ int dm_pci_find_device(unsigned int vendor, unsigned int device, int index,
 int dm_pci_find_class(uint find_class, int index, struct udevice **devp);
 
 /**
+ * struct pci_emul_uc_priv - holds info about an emulator device
+ *
+ * There is always at most one emulator per client
+ *
+ * @client: Client device if any, else NULL
+ */
+struct pci_emul_uc_priv {
+	struct udevice *client;
+};
+
+/**
  * struct dm_pci_emul_ops - PCI device emulator operations
  */
 struct dm_pci_emul_ops {
@@ -1593,6 +1604,15 @@ int sandbox_pci_get_emul(struct udevice *bus, pci_dev_t find_devfn,
 			 struct udevice **containerp, struct udevice **emulp);
 
 /**
+ * sandbox_pci_get_client() - Find the client for an emulation device
+ *
+ * @emul:	Emulation device to check
+ * @devp:	Returns the client device emulated by this device
+ * @return 0 if OK, -ENOENT if the device has no client yet
+ */
+int sandbox_pci_get_client(struct udevice *emul, struct udevice **devp);
+
+/**
  * pci_get_devfn() - Extract the devfn from fdt_pci_addr of the device
  *
  * Get devfn from fdt_pci_addr of the specified device