[U-Boot] [PATCH v2 3/7] axi: Add AXI sandbox driver and simple emulator
Mario Six
mario.six at gdsys.cc
Wed May 23 12:10:43 UTC 2018
Add test infrastructure and tests for the AXI uclass.
Signed-off-by: Mario Six <mario.six at gdsys.cc>
---
v1 -> v2:
* Spelled out abbreviations in Kconfig help
* Expanded emulation documentation
* Renamed storage pointer to storep
* Expanded AXI emulator usage documentation
* Switched AXI emulator to aligned access
---
drivers/axi/Kconfig | 7 +++
drivers/axi/Makefile | 3 ++
drivers/axi/axi-emul-uclass.c | 68 ++++++++++++++++++++++++++
drivers/axi/axi_sandbox.c | 77 +++++++++++++++++++++++++++++
drivers/axi/sandbox_store.c | 110 ++++++++++++++++++++++++++++++++++++++++++
include/axi.h | 84 ++++++++++++++++++++++++++++++++
include/dm/uclass-id.h | 1 +
7 files changed, 350 insertions(+)
create mode 100644 drivers/axi/axi-emul-uclass.c
create mode 100644 drivers/axi/axi_sandbox.c
create mode 100644 drivers/axi/sandbox_store.c
diff --git a/drivers/axi/Kconfig b/drivers/axi/Kconfig
index ae80c98af8a..f81d843f894 100644
--- a/drivers/axi/Kconfig
+++ b/drivers/axi/Kconfig
@@ -22,4 +22,11 @@ config IHS_AXI
Interface (IHS AXI) bus on a gdsys IHS FPGA used to communicate with
IP cores in the FPGA (e.g. video transmitter cores).
+config AXI_SANDBOX
+ bool "Enable AXI sandbox driver"
+ depends on DM
+ help
+ Support AXI (Advanced eXtensible Interface) emulation for the sandbox
+ environment.
+
endif
diff --git a/drivers/axi/Makefile b/drivers/axi/Makefile
index 18d9380e9ba..66b6c5a28f4 100644
--- a/drivers/axi/Makefile
+++ b/drivers/axi/Makefile
@@ -7,3 +7,6 @@
obj-$(CONFIG_AXI) += axi-uclass.o
obj-$(CONFIG_IHS_AXI) += ihs_axi.o
+obj-$(CONFIG_SANDBOX) += axi-emul-uclass.o
+obj-$(CONFIG_SANDBOX) += sandbox_store.o
+obj-$(CONFIG_AXI_SANDBOX) += axi_sandbox.o
diff --git a/drivers/axi/axi-emul-uclass.c b/drivers/axi/axi-emul-uclass.c
new file mode 100644
index 00000000000..8d37935323f
--- /dev/null
+++ b/drivers/axi/axi-emul-uclass.c
@@ -0,0 +1,68 @@
+/*
+ * (C) Copyright 2018
+ * Mario Six, Guntermann & Drunck GmbH, mario.six at gdsys.cc
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+#include <axi.h>
+#include <dm.h>
+#include <dm/device-internal.h>
+
+int axi_sandbox_get_emul(struct udevice *bus, ulong address, enum axi_size_t size,
+ struct udevice **emulp)
+{
+ struct udevice *dev;
+ u32 reg[2];
+ uint offset;
+
+ switch (size) {
+ case AXI_SIZE_8:
+ offset = 1;
+ break;
+ case AXI_SIZE_16:
+ offset = 2;
+ break;
+ case AXI_SIZE_32:
+ offset = 4;
+ break;
+ default:
+ offset = 0;
+ }
+
+ for (device_find_first_child(bus, &dev);
+ dev;
+ device_find_next_child(&dev)) {
+ int ret;
+
+ ret = dev_read_u32_array(dev, "reg", reg, ARRAY_SIZE(reg));
+ if (ret)
+ continue;
+
+ if (address >= reg[0] && address <= reg[0] + reg[1] - offset) {
+ if (device_probe(dev))
+ return -ENODEV;
+
+ *emulp = dev;
+ return 0;
+ }
+ }
+
+ return -ENODEV;
+}
+
+int axi_get_store(struct udevice *dev, u8 **storep)
+{
+ struct axi_emul_ops *ops = axi_emul_get_ops(dev);
+
+ if (!ops->get_store)
+ return -ENOSYS;
+
+ return ops->get_store(dev, storep);
+}
+
+UCLASS_DRIVER(axi_emul) = {
+ .id = UCLASS_AXI_EMUL,
+ .name = "axi_emul",
+};
diff --git a/drivers/axi/axi_sandbox.c b/drivers/axi/axi_sandbox.c
new file mode 100644
index 00000000000..7a485b114bf
--- /dev/null
+++ b/drivers/axi/axi_sandbox.c
@@ -0,0 +1,77 @@
+/*
+ * (C) Copyright 2018
+ * Mario Six, Guntermann & Drunck GmbH, mario.six at gdsys.cc
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+#include <axi.h>
+#include <dm.h>
+
+/*
+ * This driver implements a AXI bus for the sandbox architecture for testing
+ * purposes.
+ *
+ * The bus forwards every access to it to a special AXI emulation device (which
+ * it gets via the axi_emul_get_ops function) that implements a simple
+ * read/write storage.
+ *
+ * The emulator device must still be contained in the device tree in the usual
+ * way, since configuration data for the storage is read from the DT.
+ */
+
+int axi_sandbox_read(struct udevice *bus, ulong address, void *data,
+ enum axi_size_t size)
+{
+ struct axi_emul_ops *ops;
+ struct udevice *emul;
+ int ret;
+
+ /* Get emulator device */
+ ret = axi_sandbox_get_emul(bus, address, size, &emul);
+ if (ret)
+ return ret == -ENODEV ? 0 : ret;
+ /* Forward all reads to the AXI emulator */
+ ops = axi_emul_get_ops(emul);
+ if (!ops || !ops->read)
+ return -ENOSYS;
+
+ return ops->read(emul, address, data, size);
+}
+
+int axi_sandbox_write(struct udevice *bus, ulong address, void *data,
+ enum axi_size_t size)
+{
+ struct axi_emul_ops *ops;
+ struct udevice *emul;
+ int ret;
+
+ /* Get emulator device */
+ ret = axi_sandbox_get_emul(bus, address, size, &emul);
+ if (ret)
+ return ret == -ENODEV ? 0 : ret;
+ /* Forward all writes to the AXI emulator */
+ ops = axi_emul_get_ops(emul);
+ if (!ops || !ops->write)
+ return -ENOSYS;
+
+ return ops->write(emul, address, data, size);
+}
+
+static const struct udevice_id axi_sandbox_ids[] = {
+ { .compatible = "sandbox,axi" },
+ { /* sentinel */ }
+};
+
+static const struct axi_ops axi_sandbox_ops = {
+ .read = axi_sandbox_read,
+ .write = axi_sandbox_write,
+};
+
+U_BOOT_DRIVER(axi_sandbox_bus) = {
+ .name = "axi_sandbox_bus",
+ .id = UCLASS_AXI,
+ .of_match = axi_sandbox_ids,
+ .ops = &axi_sandbox_ops,
+};
diff --git a/drivers/axi/sandbox_store.c b/drivers/axi/sandbox_store.c
new file mode 100644
index 00000000000..61c7aea22c8
--- /dev/null
+++ b/drivers/axi/sandbox_store.c
@@ -0,0 +1,110 @@
+/*
+ * (C) Copyright 2018
+ * Mario Six, Guntermann & Drunck GmbH, mario.six at gdsys.cc
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+#include <axi.h>
+#include <dm.h>
+
+struct sandbox_store_priv {
+ u8 *store;
+};
+
+void copy_axi_data(void *src, void *dst, enum axi_size_t size)
+{
+ u8 *dst8 = dst;
+ u16 *dst16 = dst;
+ u32 *dst32 = dst;
+
+ switch (size) {
+ case AXI_SIZE_8:
+ *dst8 = *((u8 *)src);
+ break;
+ case AXI_SIZE_16:
+ *dst16 = be16_to_cpu(*((u16 *)src));
+ break;
+ case AXI_SIZE_32:
+ *dst32 = be32_to_cpu(*((u32 *)src));
+ break;
+ }
+}
+
+int sandbox_store_read(struct udevice *dev, ulong address, void *data,
+ enum axi_size_t size)
+{
+ struct sandbox_store_priv *priv = dev_get_priv(dev);
+
+ copy_axi_data(priv->store + address, data, size);
+
+ return 0;
+}
+
+int sandbox_store_write(struct udevice *dev, ulong address, void *data,
+ enum axi_size_t size)
+{
+ struct sandbox_store_priv *priv = dev_get_priv(dev);
+
+ copy_axi_data(data, priv->store + address, size);
+
+ return 0;
+}
+
+int sandbox_store_get_store(struct udevice *dev, u8 **store)
+{
+ struct sandbox_store_priv *priv = dev_get_priv(dev);
+
+ *store = priv->store;
+
+ return 0;
+}
+
+static const struct udevice_id sandbox_store_ids[] = {
+ { .compatible = "sandbox,sandbox_store" },
+ { /* sentinel */ }
+};
+
+static const struct axi_emul_ops sandbox_store_ops = {
+ .read = sandbox_store_read,
+ .write = sandbox_store_write,
+ .get_store = sandbox_store_get_store,
+};
+
+int sandbox_store_probe(struct udevice *dev)
+{
+ struct sandbox_store_priv *priv = dev_get_priv(dev);
+ u32 reg[2];
+ int ret;
+
+ ret = dev_read_u32_array(dev, "reg", reg, ARRAY_SIZE(reg));
+ if (ret)
+ return -EINVAL;
+
+ priv->store = calloc(reg[1], 1);
+
+ if (!priv->store)
+ return -ENOMEM;
+
+ return 0;
+}
+
+int sandbox_store_remove(struct udevice *dev)
+{
+ struct sandbox_store_priv *priv = dev_get_priv(dev);
+
+ free(priv->store);
+
+ return 0;
+}
+
+U_BOOT_DRIVER(sandbox_axi_store) = {
+ .name = "sandbox_axi_store",
+ .id = UCLASS_AXI_EMUL,
+ .of_match = sandbox_store_ids,
+ .ops = &sandbox_store_ops,
+ .priv_auto_alloc_size = sizeof(struct sandbox_store_priv),
+ .probe = sandbox_store_probe,
+ .remove = sandbox_store_remove,
+};
diff --git a/include/axi.h b/include/axi.h
index 317e931a6cf..5b428127f8c 100644
--- a/include/axi.h
+++ b/include/axi.h
@@ -72,4 +72,88 @@ int axi_read(struct udevice *dev, ulong address, void *data, enum axi_size_t siz
* @return 0 if OK, -ve on error.
*/
int axi_write(struct udevice *dev, ulong address, void *data, enum axi_size_t size);
+
+struct axi_emul_ops {
+ /**
+ * read() - Read a single value from a specified address on a AXI bus
+ *
+ * @dev: AXI bus to read from.
+ * @address: The address to read from.
+ * @data: Pointer to a variable that takes the data value read
+ * from the address on the AXI bus.
+ * @size: The size of the data to be read.
+ * @return 0 if OK, -ve on error.
+ */
+ int (*read)(struct udevice *dev, ulong address, void *data, enum axi_size_t size);
+
+ /**
+ * write() - Write a single value to a specified address on a AXI bus
+ *
+ * @dev: AXI bus to write to.
+ * @address: The address to write to.
+ * @data: Pointer to the data value to be written to the address
+ * on the AXI bus.
+ * @size: The size of the data to write.
+ * @return 0 if OK, -ve on error.
+ */
+ int (*write)(struct udevice *dev, ulong address, void *data, enum axi_size_t size);
+
+ /**
+ * get_store() - Get address of internal storage of a emulated AXI
+ * device
+ *
+ * @dev: Emulated AXI device to get the pointer of the internal
+ * storage for.
+ * @storep: Pointer to the internal storage of the emulated AXI
+ * device.
+ * @return 0 if OK, -ve on error.
+ */
+ int (*get_store)(struct udevice *dev, u8 **storep);
+};
+
+#define axi_emul_get_ops(dev) ((struct axi_emul_ops *)(dev)->driver->ops)
+
+/**
+ * axi_sandbox_get_emul() - Retrieve a pointer to a AXI emulation device
+ *
+ * To test the AXI uclass, we implement a simple AXI emulation device, which is
+ * a virtual device on a AXI bus that exposes a simple storage interface: When
+ * reading and writing from the device, the addresses are translated to offsets
+ * within the device's storage. For write accesses the data is written to the
+ * specified storage offset, and for read accesses the data is read from the
+ * specified storage offset.
+ *
+ * A DTS entry might look like this:
+ *
+ * axi: axi at 0 {
+ * compatible = "sandbox,axi";
+ * #address-cells = <0x1>;
+ * #size-cells = <0x1>;
+ * store at 0 {
+ * compatible = "sandbox,sandbox_store";
+ * reg = <0x0 0x400>;
+ * };
+ * };
+ *
+ * This function may then be used to retrieve the pointer to the sandbox_store
+ * emulation device given the AXI bus device.
+ */
+int axi_sandbox_get_emul(struct udevice *bus, ulong address, uint length,
+ struct udevice **emulp);
+/**
+ * axi_get_store() - Get address of internal storage of a emulated AXI device
+ *
+ * To preset or read back the contents internal storage of the emulated AXI
+ * device, this function returns the pointer to the storage. Changes to the
+ * contents of the storage are reflected when using the AXI read/write API
+ * methods, and vice versa, so by using this method expected read data can be
+ * set up in advance, and written data can be checked in unit tests.
+ *
+ * @dev: Emulated AXI device to get the pointer of the internal storage
+ * for.
+ * @storep: Pointer to the internal storage of the emulated AXI device.
+ * @return 0 if OK, -ve on error.
+ */
+int axi_get_store(struct udevice *dev, u8 **storep);
+
#endif
diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h
index 0aad4bc14d7..8ff1e4f1bf5 100644
--- a/include/dm/uclass-id.h
+++ b/include/dm/uclass-id.h
@@ -23,6 +23,7 @@ enum uclass_id {
UCLASS_I2C_EMUL, /* sandbox I2C device emulator */
UCLASS_PCI_EMUL, /* sandbox PCI device emulator */
UCLASS_USB_EMUL, /* sandbox USB bus device emulator */
+ UCLASS_AXI_EMUL, /* sandbox AXI bus device emulator */
UCLASS_SIMPLE_BUS, /* bus with child devices */
/* U-Boot uclasses start here - in alphabetical order */
--
2.11.0
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