[U-Boot] [PATCH v3 3/8] axi: Add AXI sandbox driver and simple emulator
Mario Six
mario.six at gdsys.cc
Thu Aug 9 12:51:18 UTC 2018
Add test infrastructure and tests for the AXI uclass.
Reviewed-by: Simon Glass <sjg at chromium.org>
Signed-off-by: Mario Six <mario.six at gdsys.cc>
---
v2 -> v3:
* Fixed style violations
* Made read/write functions static
* Reworked pointer casts for different data sizes (8/16/32 bits)
* Moved functions used only by sandbox to distinct include file
* Added full documentation
* Added debug output in error case
* Added some inline documentation
* Marked some more functions as static
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
---
arch/sandbox/include/asm/axi.h | 66 ++++++++++++++++++++++
drivers/axi/Kconfig | 7 +++
drivers/axi/Makefile | 3 +
drivers/axi/axi-emul-uclass.c | 85 ++++++++++++++++++++++++++++
drivers/axi/axi_sandbox.c | 77 ++++++++++++++++++++++++++
drivers/axi/sandbox_store.c | 123 +++++++++++++++++++++++++++++++++++++++++
include/axi.h | 74 +++++++++++++++++++------
include/dm/uclass-id.h | 1 +
8 files changed, 419 insertions(+), 17 deletions(-)
create mode 100644 arch/sandbox/include/asm/axi.h
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/arch/sandbox/include/asm/axi.h b/arch/sandbox/include/asm/axi.h
new file mode 100644
index 00000000000..d483f7b65a0
--- /dev/null
+++ b/arch/sandbox/include/asm/axi.h
@@ -0,0 +1,66 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * (C) Copyright 2018
+ * Mario Six, Guntermann & Drunck GmbH, mario.six at gdsys.cc
+ */
+
+#ifndef __asm_axi_h
+#define __asm_axi_h
+
+#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
+ * @bus: The AXI bus from which to retrieve a emulation device
+ * @address: The address of a transfer that should be handled by a emulation
+ * device
+ * @length: The data width of a transfer that should be handled by a emulation
+ * device
+ * @emulp: Pointer to a buffer receiving the emulation device that handles
+ * the transfer specified by the address and length parameters
+ *
+ * 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, and the data (address, data
+ * width) of a AXI transfer which should be handled by a emulation device.
+ *
+ * Return: 0 of OK, -ENODEV if no device capable of handling the specified
+ * transfer exists or the device could not be retrieved
+ */
+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
+ * @dev: Emulated AXI device to get the pointer of the internal storage
+ * for.
+ * @storep: Pointer to the internal storage of the 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.
+ *
+ * Return: 0 if OK, -ve on error.
+ */
+int axi_get_store(struct udevice *dev, u8 **storep);
+
+#endif /* __asm_axi_h */
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..06c42006ee8
--- /dev/null
+++ b/drivers/axi/axi-emul-uclass.c
@@ -0,0 +1,85 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2018
+ * Mario Six, Guntermann & Drunck GmbH, mario.six at gdsys.cc
+ */
+
+#include <common.h>
+#include <axi.h>
+#include <dm.h>
+#include <dm/device-internal.h>
+#include <asm/axi.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:
+ debug("%s: Unknown AXI transfer size '%d'", bus->name, size);
+ offset = 0;
+ }
+
+ /*
+ * Note: device_find_* don't activate the devices; they're activated
+ * as-needed below.
+ */
+ 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) {
+ debug("%s: Could not read 'reg' property of %s\n",
+ bus->name, dev->name);
+ continue;
+ }
+
+ /*
+ * Does the transfer's address fall into this device's address
+ * space?
+ */
+ if (address >= reg[0] && address <= reg[0] + reg[1] - offset) {
+ /* If yes, activate it... */
+ if (device_probe(dev)) {
+ debug("%s: Could not activate %s\n",
+ bus->name, dev->name);
+ return -ENODEV;
+ }
+
+ /* ...and return it */
+ *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..b91c91f6b3b
--- /dev/null
+++ b/drivers/axi/axi_sandbox.c
@@ -0,0 +1,77 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2018
+ * Mario Six, Guntermann & Drunck GmbH, mario.six at gdsys.cc
+ */
+
+#include <common.h>
+#include <axi.h>
+#include <dm.h>
+#include <asm/axi.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.
+ */
+
+static 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);
+}
+
+static 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..d724f190798
--- /dev/null
+++ b/drivers/axi/sandbox_store.c
@@ -0,0 +1,123 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2018
+ * Mario Six, Guntermann & Drunck GmbH, mario.six at gdsys.cc
+ */
+
+#include <common.h>
+#include <axi.h>
+#include <dm.h>
+
+/**
+ * struct sandbox_store_priv - Private data structure of a AXI store device
+ * @store: The buffer holding the device's internal memory, which is read from
+ * and written to using the driver's methods
+ */
+struct sandbox_store_priv {
+ u8 *store;
+};
+
+/**
+ * copy_axi_data() - Copy data from source to destination with a given AXI
+ * transfer width
+ * @src: Pointer to the data source from where data will be read
+ * @dst: Pointer to the data destination where data will be written to
+ * @size: Size of the data to be copied given by a axi_size_t enum value
+ *
+ * Return: 0 if OK, -ve on error
+ */
+static int copy_axi_data(void *src, void *dst, enum axi_size_t size)
+{
+ switch (size) {
+ case AXI_SIZE_8:
+ *((u8 *)dst) = *((u8 *)src);
+ return 0;
+ case AXI_SIZE_16:
+ *((u16 *)dst) = be16_to_cpu(*((u16 *)src));
+ return 0;
+ case AXI_SIZE_32:
+ *((u32 *)dst) = be32_to_cpu(*((u32 *)src));
+ return 0;
+ default:
+ debug("%s: Unknown AXI transfer size '%d'\n", __func__, size);
+ return -EINVAL;
+ }
+}
+
+static 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);
+
+ return copy_axi_data(priv->store + address, data, size);
+}
+
+static 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);
+
+ return copy_axi_data(data, priv->store + address, size);
+}
+
+static 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,
+};
+
+static 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) {
+ debug("%s: Could not read 'reg' property\n", dev->name);
+ return -EINVAL;
+ }
+
+ /*
+ * Allocate the device's internal storage that will be read
+ * from/written to
+ */
+ priv->store = calloc(reg[1], 1);
+ if (!priv->store)
+ return -ENOMEM;
+
+ return 0;
+}
+
+static 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 2ff81c16af6..3e40692cdfd 100644
--- a/include/axi.h
+++ b/include/axi.h
@@ -1,48 +1,47 @@
/* SPDX-License-Identifier: GPL-2.0+ */
/*
- * (C) Copyright 2017
- * Mario Six, Guntermann & Drunck GmbH, mario.six at gdsys.cc
+ * (C) Copyright 2017, 2018
+ * Mario Six, Guntermann & Drunck GmbH, mario.six at gdsys.cc
*/
#ifndef _AXI_H_
#define _AXI_H_
+/**
+ * enum axi_size_t - Determine size of AXI transfer
+ * @AXI_SIZE_8: AXI sransfer is 8-bit wide
+ * @AXI_SIZE_16: AXI sransfer is 16-bit wide
+ * @AXI_SIZE_32: AXI sransfer is 32-bit wide
+ */
enum axi_size_t {
AXI_SIZE_8,
AXI_SIZE_16,
AXI_SIZE_32,
};
-/**
- * struct axi_ops - driver operations for AXI uclass
- *
- * Drivers should support these operations unless otherwise noted. These
- * operations are intended to be used by uclass code, not directly from
- * other code.
- */
struct axi_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.
+ *
+ * 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.
+ *
+ * Return 0 if OK, -ve on error.
*/
int (*write)(struct udevice *dev, ulong address, void *data,
enum axi_size_t size);
@@ -52,27 +51,68 @@ struct axi_ops {
/**
* axi_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 write.
- * @return 0 if OK, -ve on error.
+ *
+ * Return: 0 if OK, -ve on error.
*/
int axi_read(struct udevice *dev, ulong address, void *data,
enum axi_size_t size);
/**
* axi_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.
+ *
+ * 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);
+};
+
#endif
diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h
index 618f43ad458..7027ea076db 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
More information about the U-Boot
mailing list