[U-Boot] [PATCH v2 3/7] axi: Add AXI sandbox driver and simple emulator
Simon Glass
sjg at chromium.org
Fri May 25 02:41:21 UTC 2018
Hi Mario,
On 23 May 2018 at 06:10, Mario Six <mario.six at gdsys.cc> wrote:
> 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
>
Reviewed-by: Simon Glass <sjg at chromium.org>
Some nits below.
> 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)
Can this and the write() function below be static?
> +{
> + 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;
Can you put these declarations in the case statements instead? I'm not
sure what coverity with think of this aliasing.
> +
> + 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);
> +
drop blank line
> + 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);
Can these two function declarations go in arch/sandbox/include/asm
perhaps? I don't think they are needed except for sandbox?
> +/**
> + * 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
Regards,
Simon
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