[U-Boot] [PATCH v3 037/108] sandbox: Add PCI driver and test for p2sb

[Bin Meng <bmeng.cn@gmail.com>]

Hi Simon,

On Mon, Oct 21, 2019 at 11:40 AM Simon Glass <sjg@chromium.org> wrote:
>
> Add a sandbox driver and PCI-device emulator for p2sb. Also add a test
> which uses a simple 'adder' driver to test the p2sb functionality.
>
> Signed-off-by: Simon Glass <sjg@chromium.org>
> ---
>
> Changes in v3:
> - Fix build errors in sandbox_spl, etc
>
> Changes in v2: None
>
>  arch/sandbox/cpu/state.c           |   1 +
>  arch/sandbox/dts/test.dts          |  13 ++
>  arch/sandbox/include/asm/test.h    |  10 ++
>  configs/sandbox64_defconfig        |   2 +
>  configs/sandbox_flattree_defconfig |   3 +
>  configs/sandbox_spl_defconfig      |   2 +
>  configs/tools-only_defconfig       |   2 +
>  drivers/core/uclass.c              |   4 +-
>  drivers/misc/Makefile              |   2 +
>  drivers/misc/p2sb_emul.c           | 272 +++++++++++++++++++++++++++++
>  drivers/misc/p2sb_sandbox.c        |  44 +++++
>  drivers/misc/sandbox_adder.c       |  60 +++++++
>  test/dm/Makefile                   |   1 +
>  test/dm/p2sb.c                     |  28 +++
>  14 files changed, 442 insertions(+), 2 deletions(-)
>  create mode 100644 drivers/misc/p2sb_emul.c
>  create mode 100644 drivers/misc/p2sb_sandbox.c
>  create mode 100644 drivers/misc/sandbox_adder.c
>  create mode 100644 test/dm/p2sb.c
>
> diff --git a/arch/sandbox/cpu/state.c b/arch/sandbox/cpu/state.c
> index dee5fde4f73..cd46e000f5e 100644
> --- a/arch/sandbox/cpu/state.c
> +++ b/arch/sandbox/cpu/state.c
> @@ -356,6 +356,7 @@ void state_reset_for_test(struct sandbox_state *state)
>         /* No reset yet, so mark it as such. Always allow power reset */
>         state->last_sysreset = SYSRESET_COUNT;
>         state->sysreset_allowed[SYSRESET_POWER_OFF] = true;
> +       state->allow_memio = false;

A separate patch?

>
>         memset(&state->wdt, '\0', sizeof(state->wdt));
>         memset(state->spi, '\0', sizeof(state->spi));
> diff --git a/arch/sandbox/dts/test.dts b/arch/sandbox/dts/test.dts
> index 5c1093df282..24631770544 100644
> --- a/arch/sandbox/dts/test.dts
> +++ b/arch/sandbox/dts/test.dts
> @@ -467,6 +467,16 @@
>                                0x01000810 0 0 0 0>;
>                         sandbox,emul = <&swap_case_emul0_1>;
>                 };
> +               p2sb-pci at 2,0 {
> +                       compatible = "sandbox,p2sb";
> +                       reg = <0x02001010 0 0 0 0>;
> +                       sandbox,emul = <&p2sb_emul>;
> +
> +                       adder {
> +                               intel,p2sb-port-id = <3>;
> +                               compatible = "sandbox,adder";
> +                       };
> +               };
>                 pci at 1e,0 {
>                         compatible = "sandbox,pmc";
>                         reg = <0xf000 0 0 0 0>;
> @@ -498,6 +508,9 @@
>                 swap_case_emul0_1f: emul0 at 1f,0 {
>                         compatible = "sandbox,swap-case";
>                 };
> +               p2sb_emul: emul at 2,0 {
> +                       compatible = "sandbox,p2sb-emul";
> +               };
>                 pmc_emul1e: emul at 1e,0 {
>                         compatible = "sandbox,pmc-emul";
>                 };
> diff --git a/arch/sandbox/include/asm/test.h b/arch/sandbox/include/asm/test.h
> index 7f9e7fc26f5..77fff529e19 100644
> --- a/arch/sandbox/include/asm/test.h
> +++ b/arch/sandbox/include/asm/test.h
> @@ -14,6 +14,7 @@
>  #define SANDBOX_PCI_VENDOR_ID          0x1234
>  #define SANDBOX_PCI_SWAP_CASE_EMUL_ID  0x5678
>  #define SANDBOX_PCI_PMC_EMUL_ID                0x5677
> +#define SANDBOX_PCI_P2SB_EMUL_ID       0x5676
>  #define SANDBOX_PCI_CLASS_CODE         PCI_CLASS_CODE_COMM
>  #define SANDBOX_PCI_CLASS_SUB_CODE     PCI_CLASS_SUB_CODE_COMM_SERIAL
>
> @@ -214,4 +215,13 @@ int sandbox_get_pci_ep_irq_count(struct udevice *dev);
>   */
>  uint sandbox_pci_read_bar(u32 barval, int type, uint size);
>
> +/**
> + * sandbox_set_enable_memio() - Enable memory-mapped I/O read/write
> + *
> + * Normally readl(), writel() and the like are nops on sandbox. If this function
> + * is called with true, those function do real memory accesses. This is useful
> + * for certain tests.
> + */
> +void sandbox_set_enable_memio(bool enable);
> +

A separate patch?

>  #endif
> diff --git a/configs/sandbox64_defconfig b/configs/sandbox64_defconfig
> index 1fea683d892..4c86141ffb1 100644
> --- a/configs/sandbox64_defconfig
> +++ b/configs/sandbox64_defconfig
> @@ -81,6 +81,8 @@ CONFIG_DEVRES=y
>  CONFIG_DEBUG_DEVRES=y
>  CONFIG_ADC=y
>  CONFIG_ADC_SANDBOX=y
> +CONFIG_AXI=y
> +CONFIG_AXI_SANDBOX=y
>  CONFIG_CLK=y
>  CONFIG_CPU=y
>  CONFIG_DM_DEMO=y
> diff --git a/configs/sandbox_flattree_defconfig b/configs/sandbox_flattree_defconfig
> index 898815fe531..230d65b14a7 100644
> --- a/configs/sandbox_flattree_defconfig
> +++ b/configs/sandbox_flattree_defconfig
> @@ -65,6 +65,8 @@ CONFIG_DEVRES=y
>  CONFIG_DEBUG_DEVRES=y
>  CONFIG_ADC=y
>  CONFIG_ADC_SANDBOX=y
> +CONFIG_AXI=y
> +CONFIG_AXI_SANDBOX=y
>  CONFIG_CLK=y
>  CONFIG_CLK_COMPOSITE_CCF=y
>  CONFIG_SANDBOX_CLK_CCF=y
> @@ -116,6 +118,7 @@ CONFIG_PCI=y
>  CONFIG_DM_PCI=y
>  CONFIG_DM_PCI_COMPAT=y
>  CONFIG_PCI_SANDBOX=y
> +CONFIG_P2SB=y
>  CONFIG_PHY=y
>  CONFIG_PHY_SANDBOX=y
>  CONFIG_PINCTRL=y
> diff --git a/configs/sandbox_spl_defconfig b/configs/sandbox_spl_defconfig
> index c49e05ec319..405b6015474 100644
> --- a/configs/sandbox_spl_defconfig
> +++ b/configs/sandbox_spl_defconfig
> @@ -86,6 +86,8 @@ CONFIG_DEBUG_DEVRES=y
>  # CONFIG_SPL_SIMPLE_BUS is not set
>  CONFIG_ADC=y
>  CONFIG_ADC_SANDBOX=y
> +CONFIG_AXI=y
> +CONFIG_AXI_SANDBOX=y
>  CONFIG_CLK=y
>  CONFIG_CPU=y
>  CONFIG_DM_DEMO=y
> diff --git a/configs/tools-only_defconfig b/configs/tools-only_defconfig
> index 4808b498502..35f5ca74065 100644
> --- a/configs/tools-only_defconfig
> +++ b/configs/tools-only_defconfig
> @@ -11,6 +11,8 @@ CONFIG_OF_HOSTFILE=y
>  CONFIG_DEFAULT_DEVICE_TREE="sandbox"
>  CONFIG_IP_DEFRAG=y
>  # CONFIG_UDP_FUNCTION_FASTBOOT is not set
> +CONFIG_AXI=y
> +CONFIG_AXI_SANDBOX=y
>  CONFIG_SANDBOX_GPIO=y
>  CONFIG_PCI=y
>  CONFIG_DM_PCI=y
> diff --git a/drivers/core/uclass.c b/drivers/core/uclass.c
> index 36f4d1c289d..57f619cca3b 100644
> --- a/drivers/core/uclass.c
> +++ b/drivers/core/uclass.c
> @@ -56,8 +56,8 @@ static int uclass_add(enum uclass_id id, struct uclass **ucp)
>         *ucp = NULL;
>         uc_drv = lists_uclass_lookup(id);
>         if (!uc_drv) {
> -               debug("Cannot find uclass for id %d: please add the UCLASS_DRIVER() declaration for this UCLASS_... id\n",
> -                     id);
> +               printf("Cannot find uclass for id %d: please add the UCLASS_DRIVER() declaration for this UCLASS_... id\n",
> +                      id);

Looks unrelated to this patch.

>                 /*
>                  * Use a strange error to make this case easier to find. When
>                  * a uclass is not available it can prevent driver model from
> diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
> index 840d9fa5e39..363864454bd 100644
> --- a/drivers/misc/Makefile
> +++ b/drivers/misc/Makefile
> @@ -10,8 +10,10 @@ obj-$(CONFIG_$(SPL_TPL_)CROS_EC_SANDBOX) += cros_ec_sandbox.o
>  obj-$(CONFIG_$(SPL_TPL_)CROS_EC_LPC) += cros_ec_lpc.o
>
>  ifndef CONFIG_SPL_BUILD
> +obj-$(CONFIG_SANDBOX) += sandbox_adder.o
>  obj-$(CONFIG_CROS_EC_I2C) += cros_ec_i2c.o
>  obj-$(CONFIG_CROS_EC_SPI) += cros_ec_spi.o
> +obj-$(CONFIG_SANDBOX) += p2sb_sandbox.o p2sb_emul.o
>  obj-$(CONFIG_SANDBOX) += swap_case.o
>  endif
>
> diff --git a/drivers/misc/p2sb_emul.c b/drivers/misc/p2sb_emul.c
> new file mode 100644
> index 00000000000..c3795c59c08
> --- /dev/null
> +++ b/drivers/misc/p2sb_emul.c
> @@ -0,0 +1,272 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * PCI emulation device for an x86 Primary-to-Sideband bus
> + *
> + * Copyright 2019 Google LLC
> + * Written by Simon Glass <sjg@chromium.org>
> + */
> +
> +#define LOG_CATEGORY UCLASS_MISC
> +#define LOG_DEBUG
> +
> +#include <common.h>
> +#include <axi.h>
> +#include <dm.h>
> +#include <pci.h>
> +#include <asm/test.h>
> +#include <p2sb.h>
> +
> +/**
> + * struct p2sb_emul_platdata - platform data for this device
> + *
> + * @command:   Current PCI command value
> + * @bar:       Current base address values
> + */
> +struct p2sb_emul_platdata {
> +       u16 command;
> +       u32 bar[6];
> +};
> +
> +enum {
> +       /* This emulator supports 16 different devices */
> +       MEMMAP_SIZE     = 16 << PCR_PORTID_SHIFT,
> +};
> +
> +static struct pci_bar {
> +       int type;
> +       u32 size;
> +} barinfo[] = {
> +       { PCI_BASE_ADDRESS_MEM_TYPE_32, MEMMAP_SIZE },
> +       { 0, 0 },
> +       { 0, 0 },
> +       { 0, 0 },
> +       { 0, 0 },
> +       { 0, 0 },
> +};
> +
> +struct p2sb_emul_priv {
> +       u8 regs[16];
> +};
> +
> +static int sandbox_p2sb_emul_read_config(struct udevice *emul, uint offset,
> +                                        ulong *valuep, enum pci_size_t size)
> +{
> +       struct p2sb_emul_platdata *plat = dev_get_platdata(emul);
> +
> +       switch (offset) {
> +       case PCI_COMMAND:
> +               *valuep = plat->command;
> +               break;
> +       case PCI_HEADER_TYPE:
> +               *valuep = PCI_HEADER_TYPE_NORMAL;
> +               break;
> +       case PCI_VENDOR_ID:
> +               *valuep = SANDBOX_PCI_VENDOR_ID;
> +               break;
> +       case PCI_DEVICE_ID:
> +               *valuep = SANDBOX_PCI_P2SB_EMUL_ID;
> +               break;
> +       case PCI_CLASS_DEVICE:
> +               if (size == PCI_SIZE_8) {
> +                       *valuep = SANDBOX_PCI_CLASS_SUB_CODE;
> +               } else {
> +                       *valuep = (SANDBOX_PCI_CLASS_CODE << 8) |
> +                                       SANDBOX_PCI_CLASS_SUB_CODE;
> +               }
> +               break;
> +       case PCI_CLASS_CODE:
> +               *valuep = SANDBOX_PCI_CLASS_CODE;
> +               break;
> +       case PCI_BASE_ADDRESS_0:
> +       case PCI_BASE_ADDRESS_1:
> +       case PCI_BASE_ADDRESS_2:
> +       case PCI_BASE_ADDRESS_3:
> +       case PCI_BASE_ADDRESS_4:
> +       case PCI_BASE_ADDRESS_5: {
> +               int barnum;
> +               u32 *bar;
> +
> +               barnum = pci_offset_to_barnum(offset);
> +               bar = &plat->bar[barnum];
> +
> +               *valuep = sandbox_pci_read_bar(*bar, barinfo[barnum].type,
> +                                              barinfo[barnum].size);
> +               break;
> +       }
> +       case PCI_CAPABILITY_LIST:
> +               *valuep = PCI_CAP_ID_PM_OFFSET;
> +               break;
> +       }
> +
> +       return 0;
> +}
> +
> +static int sandbox_p2sb_emul_write_config(struct udevice *emul, uint offset,
> +                                         ulong value, enum pci_size_t size)
> +{
> +       struct p2sb_emul_platdata *plat = dev_get_platdata(emul);
> +
> +       switch (offset) {
> +       case PCI_COMMAND:
> +               plat->command = value;
> +               break;
> +       case PCI_BASE_ADDRESS_0:
> +       case PCI_BASE_ADDRESS_1: {
> +               int barnum;
> +               u32 *bar;
> +
> +               barnum = pci_offset_to_barnum(offset);
> +               bar = &plat->bar[barnum];
> +
> +               log_debug("w bar %d=%lx\n", barnum, value);
> +               *bar = value;
> +               /* space indicator (bit#0) is read-only */
> +               *bar |= barinfo[barnum].type;
> +               break;
> +       }
> +       }
> +
> +       return 0;
> +}
> +
> +static int sandbox_p2sb_emul_find_bar(struct udevice *emul, unsigned int addr,
> +                                     int *barnump, unsigned int *offsetp)
> +{
> +       struct p2sb_emul_platdata *plat = dev_get_platdata(emul);
> +       int barnum;
> +
> +       for (barnum = 0; barnum < ARRAY_SIZE(barinfo); barnum++) {
> +               unsigned int size = barinfo[barnum].size;
> +               u32 base = plat->bar[barnum] & ~PCI_BASE_ADDRESS_SPACE;
> +
> +               if (addr >= base && addr < base + size) {
> +                       *barnump = barnum;
> +                       *offsetp = addr - base;
> +                       return 0;
> +               }
> +       }
> +       *barnump = -1;
> +
> +       return -ENOENT;
> +}
> +
> +static int sandbox_p2sb_emul_read_io(struct udevice *dev, unsigned int addr,
> +                                    ulong *valuep, enum pci_size_t size)
> +{
> +       unsigned int offset;
> +       int barnum;
> +       int ret;
> +
> +       ret = sandbox_p2sb_emul_find_bar(dev, addr, &barnum, &offset);
> +       if (ret)
> +               return ret;
> +
> +       if (barnum == 4)
> +               *valuep = offset;
> +       else if (barnum == 0)
> +               *valuep = offset;
> +
> +       return 0;
> +}
> +
> +static int sandbox_p2sb_emul_write_io(struct udevice *dev, unsigned int addr,
> +                                     ulong value, enum pci_size_t size)
> +{
> +       unsigned int offset;
> +       int barnum;
> +       int ret;
> +
> +       ret = sandbox_p2sb_emul_find_bar(dev, addr, &barnum, &offset);
> +       if (ret)
> +               return ret;
> +
> +       return 0;
> +}
> +
> +static int find_p2sb_channel(struct udevice *emul, uint offset,
> +                            struct udevice **devp)
> +{
> +       uint pid = offset >> PCR_PORTID_SHIFT;
> +       struct udevice *p2sb, *dev;
> +       int ret;
> +
> +       ret = sandbox_pci_get_client(emul, &p2sb);
> +       if (ret)
> +               return log_msg_ret("No client", ret);
> +
> +       device_foreach_child(dev, p2sb) {
> +               struct p2sb_child_platdata *pplat =
> +                        dev_get_parent_platdata(dev);
> +
> +               log_debug("   - child %s, pid %d, want %d\n", dev->name,
> +                         pplat->pid, pid);
> +               if (pid == pplat->pid) {
> +                       *devp = dev;
> +                       return 0;
> +               }
> +       }
> +
> +       return -ENOENT;
> +}
> +
> +static int sandbox_p2sb_emul_map_physmem(struct udevice *dev,
> +                                        phys_addr_t addr, unsigned long *lenp,
> +                                        void **ptrp)
> +{
> +       struct p2sb_emul_priv *priv = dev_get_priv(dev);
> +       struct udevice *child;
> +       unsigned int offset;
> +       int barnum;
> +       int ret;
> +
> +       log_debug("map %x: ", (uint)addr);
> +       ret = sandbox_p2sb_emul_find_bar(dev, addr, &barnum, &offset);
> +       if (ret)
> +               return log_msg_ret("Cannot find bar", ret);
> +       log_debug("bar %d, offset %x\n", barnum, offset);
> +
> +       if (barnum != 0)
> +               return log_msg_ret("Unknown BAR", -EINVAL);
> +
> +       ret = find_p2sb_channel(dev, offset, &child);
> +       if (ret)
> +               return log_msg_ret("Cannot find channel", ret);
> +
> +       offset &= ((1 << PCR_PORTID_SHIFT) - 1);
> +       ret = axi_read(child, offset, priv->regs, AXI_SIZE_32);
> +       if (ret)
> +               return log_msg_ret("Child read failed", ret);
> +       *ptrp = priv->regs + (offset & 3);
> +       *lenp = 4;
> +
> +       return 0;
> +}
> +
> +static struct dm_pci_emul_ops sandbox_p2sb_emul_emul_ops = {
> +       .read_config = sandbox_p2sb_emul_read_config,
> +       .write_config = sandbox_p2sb_emul_write_config,
> +       .read_io = sandbox_p2sb_emul_read_io,
> +       .write_io = sandbox_p2sb_emul_write_io,
> +       .map_physmem = sandbox_p2sb_emul_map_physmem,
> +};
> +
> +static const struct udevice_id sandbox_p2sb_emul_ids[] = {
> +       { .compatible = "sandbox,p2sb-emul" },
> +       { }
> +};
> +
> +U_BOOT_DRIVER(sandbox_p2sb_emul_emul) = {
> +       .name           = "sandbox_p2sb_emul_emul",
> +       .id             = UCLASS_PCI_EMUL,
> +       .of_match       = sandbox_p2sb_emul_ids,
> +       .ops            = &sandbox_p2sb_emul_emul_ops,
> +       .priv_auto_alloc_size = sizeof(struct p2sb_emul_priv),
> +       .platdata_auto_alloc_size = sizeof(struct p2sb_emul_platdata),
> +};
> +
> +static struct pci_device_id sandbox_p2sb_emul_supported[] = {
> +       { PCI_VDEVICE(SANDBOX, SANDBOX_PCI_PMC_EMUL_ID) },
> +       {},
> +};
> +
> +U_BOOT_PCI_DEVICE(sandbox_p2sb_emul_emul, sandbox_p2sb_emul_supported);
> diff --git a/drivers/misc/p2sb_sandbox.c b/drivers/misc/p2sb_sandbox.c
> new file mode 100644
> index 00000000000..2337df9951d
> --- /dev/null
> +++ b/drivers/misc/p2sb_sandbox.c
> @@ -0,0 +1,44 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Sandbox P2SB for testing
> + *
> + * Copyright 2019 Google LLC
> + */
> +
> +#define LOG_CATEGORY UCLASS_P2SB
> +
> +#include <common.h>
> +#include <dm.h>
> +#include <asm/io.h>
> +#include <p2sb.h>
> +
> +struct sandbox_p2sb_priv {
> +       ulong base;
> +};
> +
> +static int sandbox_p2sb_probe(struct udevice *dev)
> +{
> +       struct p2sb_uc_priv *upriv = dev_get_uclass_priv(dev);
> +
> +       upriv->mmio_base = dm_pci_read_bar32(dev, 0);
> +       printf("mmio base %x\n", upriv->mmio_base);
> +
> +       return 0;
> +}
> +
> +static struct p2sb_ops sandbox_p2sb_ops = {
> +};

Could this be dropped, since it's an empty struct?

> +
> +static const struct udevice_id sandbox_p2sb_ids[] = {
> +       { .compatible = "sandbox,p2sb" },
> +       { }
> +};
> +
> +U_BOOT_DRIVER(p2sb_sandbox) = {
> +       .name = "pmic_pm8916",

The name does not look correct.

> +       .id = UCLASS_P2SB,
> +       .of_match = sandbox_p2sb_ids,
> +       .probe = sandbox_p2sb_probe,
> +       .ops = &sandbox_p2sb_ops,
> +       .priv_auto_alloc_size = sizeof(struct sandbox_p2sb_priv),
> +};
> diff --git a/drivers/misc/sandbox_adder.c b/drivers/misc/sandbox_adder.c
> new file mode 100644
> index 00000000000..df262e62555
> --- /dev/null
> +++ b/drivers/misc/sandbox_adder.c
> @@ -0,0 +1,60 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Sandbox adder for p2sb testing
> + *
> + * Copyright 2019 Google LLC
> + */
> +
> +#define LOG_CATEGORY UCLASS_MISC
> +
> +#include <common.h>
> +#include <axi.h>
> +#include <dm.h>
> +#include <misc.h>
> +#include <p2sb.h>
> +#include <asm/io.h>
> +
> +struct sandbox_adder_priv {
> +       ulong base;
> +};
> +
> +int sandbox_adder_read(struct udevice *dev, ulong address, void *data,
> +                      enum axi_size_t size)
> +{
> +       struct p2sb_child_platdata *pplat = dev_get_parent_platdata(dev);
> +       u32 *val = data;
> +
> +       *val = pplat->pid << 24 | address;
> +
> +       return 0;
> +}
> +
> +int sandbox_adder_write(struct udevice *dev, ulong address, void *data,
> +                       enum axi_size_t size)
> +{
> +       return 0;
> +}
> +
> +static int sandbox_adder_probe(struct udevice *dev)
> +{
> +       return 0;
> +}
> +
> +static struct axi_ops sandbox_adder_ops = {
> +       .read   = sandbox_adder_read,
> +       .write  = sandbox_adder_write,
> +};
> +
> +static const struct udevice_id sandbox_adder_ids[] = {
> +       { .compatible = "sandbox,adder" },
> +       { }
> +};
> +
> +U_BOOT_DRIVER(adder_sandbox) = {
> +       .name = "sandbox_adder",
> +       .id = UCLASS_AXI,
> +       .of_match = sandbox_adder_ids,
> +       .probe = sandbox_adder_probe,
> +       .ops = &sandbox_adder_ops,
> +       .priv_auto_alloc_size = sizeof(struct sandbox_adder_priv),
> +};
> diff --git a/test/dm/Makefile b/test/dm/Makefile
> index 10a19a00c90..129ccb3b496 100644
> --- a/test/dm/Makefile
> +++ b/test/dm/Makefile
> @@ -32,6 +32,7 @@ obj-y += ofnode.o
>  obj-$(CONFIG_OSD) += osd.o
>  obj-$(CONFIG_DM_VIDEO) += panel.o
>  obj-$(CONFIG_DM_PCI) += pci.o
> +obj-$(CONFIG_P2SB) += p2sb.o
>  obj-$(CONFIG_PCI_ENDPOINT) += pci_ep.o
>  obj-$(CONFIG_PCH) += pch.o
>  obj-$(CONFIG_PHY) += phy.o
> diff --git a/test/dm/p2sb.c b/test/dm/p2sb.c
> new file mode 100644
> index 00000000000..ccb75cf3753
> --- /dev/null
> +++ b/test/dm/p2sb.c
> @@ -0,0 +1,28 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Test for Primary-to-Sideband bus (P2SB)
> + *
> + * Copyright 2019 Google LLC
> + */
> +
> +#include <common.h>
> +#include <dm.h>
> +#include <p2sb.h>
> +#include <asm/test.h>
> +#include <dm/test.h>
> +#include <test/ut.h>
> +
> +/* Base test of the PMC uclass */
> +static int dm_test_p2sb_base(struct unit_test_state *uts)
> +{
> +       struct udevice *dev;
> +
> +       sandbox_set_enable_memio(true);
> +       ut_assertok(uclass_get_device_by_name(UCLASS_AXI, "adder", &dev));
> +       ut_asserteq(0x03000004, pcr_read32(dev, 4));
> +       ut_asserteq(0x300, pcr_read16(dev, 6));
> +       ut_asserteq(4, pcr_read8(dev, 4));
> +
> +       return 0;
> +}
> +DM_TEST(dm_test_p2sb_base, DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT);
> --

Regards,
Bin