[v6,024/102] sandbox: Add PCI driver and test for p2sb
diff mbox series

Message ID 20191206213936.v6.24.I838b4b33c91a8000743aea498b139d915e95de4a@changeid
State Accepted
Commit 3e17ffbb44cd24c53504179ff51a835502b183ed
Delegated to: Bin Meng
Headers show
Series
  • x86: Add initial support for apollolake
Related show

Commit Message

Simon Glass Dec. 7, 2019, 4:41 a.m. UTC
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>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
---

Changes in v6:
- Correct a few unrelated defconfig changes
- Drop unwanted debug printf()

Changes in v5: None
Changes in v4:
- Drop change to message about a missing uclass
- Drop empty operations struct since p2sb does not need it
- Drop pmic_pm8916 driver name and use a sandbox name instead
- Split out mmio changes into a separate patch

Changes in v3:
- Fix build errors in sandbox_spl, etc

Changes in v2: None

 arch/sandbox/dts/test.dts          |  13 ++
 arch/sandbox/include/asm/test.h    |   1 +
 configs/sandbox64_defconfig        |   3 +
 configs/sandbox_defconfig          |   1 +
 configs/sandbox_flattree_defconfig |   3 +
 configs/sandbox_spl_defconfig      |   3 +
 configs/tools-only_defconfig       |   2 +
 drivers/misc/Makefile              |   2 +
 drivers/misc/p2sb_emul.c           | 272 +++++++++++++++++++++++++++++
 drivers/misc/p2sb_sandbox.c        |  39 +++++
 drivers/misc/sandbox_adder.c       |  60 +++++++
 test/dm/Makefile                   |   1 +
 test/dm/p2sb.c                     |  28 +++
 13 files changed, 428 insertions(+)
 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

Comments

Bin Meng Dec. 8, 2019, 2:53 a.m. UTC | #1
On Sat, Dec 7, 2019 at 12:47 PM 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>
> Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
> ---
>
> Changes in v6:
> - Correct a few unrelated defconfig changes
> - Drop unwanted debug printf()
>
> Changes in v5: None
> Changes in v4:
> - Drop change to message about a missing uclass
> - Drop empty operations struct since p2sb does not need it
> - Drop pmic_pm8916 driver name and use a sandbox name instead
> - Split out mmio changes into a separate patch
>
> Changes in v3:
> - Fix build errors in sandbox_spl, etc
>
> Changes in v2: None
>
>  arch/sandbox/dts/test.dts          |  13 ++
>  arch/sandbox/include/asm/test.h    |   1 +
>  configs/sandbox64_defconfig        |   3 +
>  configs/sandbox_defconfig          |   1 +
>  configs/sandbox_flattree_defconfig |   3 +
>  configs/sandbox_spl_defconfig      |   3 +
>  configs/tools-only_defconfig       |   2 +
>  drivers/misc/Makefile              |   2 +
>  drivers/misc/p2sb_emul.c           | 272 +++++++++++++++++++++++++++++
>  drivers/misc/p2sb_sandbox.c        |  39 +++++
>  drivers/misc/sandbox_adder.c       |  60 +++++++
>  test/dm/Makefile                   |   1 +
>  test/dm/p2sb.c                     |  28 +++
>  13 files changed, 428 insertions(+)
>  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
>

applied to u-boot-x86/next, thanks!

Patch
diff mbox series

diff --git a/arch/sandbox/dts/test.dts b/arch/sandbox/dts/test.dts
index 99905677ab..9c8c4e2709 100644
--- a/arch/sandbox/dts/test.dts
+++ b/arch/sandbox/dts/test.dts
@@ -471,6 +471,16 @@ 
 			       0x01000810 0 0 0 0>;
 			sandbox,emul = <&swap_case_emul0_1>;
 		};
+		p2sb-pci@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@1e,0 {
 			compatible = "sandbox,pmc";
 			reg = <0xf000 0 0 0 0>;
@@ -502,6 +512,9 @@ 
 		swap_case_emul0_1f: emul0@1f,0 {
 			compatible = "sandbox,swap-case";
 		};
+		p2sb_emul: emul@2,0 {
+			compatible = "sandbox,p2sb-emul";
+		};
 		pmc_emul1e: emul@1e,0 {
 			compatible = "sandbox,pmc-emul";
 		};
diff --git a/arch/sandbox/include/asm/test.h b/arch/sandbox/include/asm/test.h
index fa40d21f3f..fdb0ecfed1 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
 
diff --git a/configs/sandbox64_defconfig b/configs/sandbox64_defconfig
index d467841205..d1ca9eb3da 100644
--- a/configs/sandbox64_defconfig
+++ b/configs/sandbox64_defconfig
@@ -83,6 +83,8 @@  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
@@ -202,3 +204,4 @@  CONFIG_TEST_FDTDEC=y
 CONFIG_UNIT_TEST=y
 CONFIG_UT_TIME=y
 CONFIG_UT_DM=y
+CONFIG_P2SB=y
diff --git a/configs/sandbox_defconfig b/configs/sandbox_defconfig
index ed7ff78a86..cc8b44ad28 100644
--- a/configs/sandbox_defconfig
+++ b/configs/sandbox_defconfig
@@ -132,6 +132,7 @@  CONFIG_CROS_EC_I2C=y
 CONFIG_CROS_EC_LPC=y
 CONFIG_CROS_EC_SANDBOX=y
 CONFIG_CROS_EC_SPI=y
+CONFIG_P2SB=y
 CONFIG_PWRSEQ=y
 CONFIG_SPL_PWRSEQ=y
 CONFIG_I2C_EEPROM=y
diff --git a/configs/sandbox_flattree_defconfig b/configs/sandbox_flattree_defconfig
index 02969f95f1..8477542cb5 100644
--- a/configs/sandbox_flattree_defconfig
+++ b/configs/sandbox_flattree_defconfig
@@ -67,6 +67,8 @@  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
@@ -117,6 +119,7 @@  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 3b0f15de88..bcc04f0877 100644
--- a/configs/sandbox_spl_defconfig
+++ b/configs/sandbox_spl_defconfig
@@ -88,6 +88,8 @@  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
@@ -201,3 +203,4 @@  CONFIG_ERRNO_STR=y
 CONFIG_UNIT_TEST=y
 CONFIG_UT_TIME=y
 CONFIG_UT_DM=y
+CONFIG_P2SB=y
diff --git a/configs/tools-only_defconfig b/configs/tools-only_defconfig
index e36c9debf6..c698be67ea 100644
--- a/configs/tools-only_defconfig
+++ b/configs/tools-only_defconfig
@@ -13,6 +13,8 @@  CONFIG_DEFAULT_DEVICE_TREE="sandbox"
 CONFIG_SYS_RELOC_GD_ENV_ADDR=y
 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/misc/Makefile b/drivers/misc/Makefile
index 78b598b367..44c9e3ef08 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 0000000000..c3795c59c0
--- /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 0000000000..ce50a9732e
--- /dev/null
+++ b/drivers/misc/p2sb_sandbox.c
@@ -0,0 +1,39 @@ 
+// 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);
+
+	return 0;
+}
+
+static const struct udevice_id sandbox_p2sb_ids[] = {
+	{ .compatible = "sandbox,p2sb" },
+	{ }
+};
+
+U_BOOT_DRIVER(p2sb_sandbox) = {
+	.name = "p2sb_sandbox",
+	.id = UCLASS_P2SB,
+	.of_match = sandbox_p2sb_ids,
+	.probe = sandbox_p2sb_probe,
+	.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 0000000000..df262e6255
--- /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 10a19a00c9..129ccb3b49 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 0000000000..ccb75cf375
--- /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);