From: Laurentiu Mihalcea <laurentiu.mihalcea@nxp.com>

Some DSP instances may have their access to certain peripherals

conditioned by a bus access controller such as the one from the

AIPSTZ bridge.

Add the optional 'access-controllers' property, which may be used

in such cases.

Signed-off-by: Laurentiu Mihalcea <laurentiu.mihalcea@nxp.com>

Reviewed-by: Frank Li <Frank.Li@nxp.com>

Acked-by: Rob Herring (Arm) <robh@kernel.org>

---

Documentation/devicetree/bindings/dsp/fsl,dsp.yaml | 3 +++

1 file changed, 3 insertions(+)

diff --git a/Documentation/devicetree/bindings/dsp/fsl,dsp.yaml b/Documentation/devicetree/bindings/dsp/fsl,dsp.yaml

index XXXXXXX..XXXXXXX 100644

--- a/Documentation/devicetree/bindings/dsp/fsl,dsp.yaml

+++ b/Documentation/devicetree/bindings/dsp/fsl,dsp.yaml

@@ -XXX,XX +XXX,XX @@ properties:

- const: runstall

- const: softreset

+ access-controllers:

+ maxItems: 1

+

required:

- compatible

- reg

--

2.34.1

From: Laurentiu Mihalcea <laurentiu.mihalcea@nxp.com>

The secure AHB to IP Slave (AIPSTZ) bus bridge provides access control

configurations meant to restrict access to certain peripherals.

Some of the configurations include:

    1) Marking masters as trusted for R/W. Based on this

    (and the configuration of the accessed peripheral), the bridge

    may choose to abort the R/W transactions issued by certain

    masters.

    2) Allowing/disallowing write accesses to peripherals.

Add driver for this IP. Since there's currently no framework for

access controllers (and since there's currently no need for having

flexibility w.r.t the configurations) all this driver does is it

applies a relaxed, "default" configuration, in which all masters

are trusted for R/W.

Note that some instances of this IP (e.g: AIPSTZ5 on i.MX8MP) may be tied

to a power domain and may lose their configuration when the domain is

powered off. This is why the configuration has to be restored when the

domain is powered on.

Co-developed-by: Daniel Baluta <daniel.baluta@nxp.com>

Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com>

Signed-off-by: Laurentiu Mihalcea <laurentiu.mihalcea@nxp.com>

---

drivers/bus/Kconfig | 6 +++

drivers/bus/Makefile | 1 +

drivers/bus/imx-aipstz.c | 92 ++++++++++++++++++++++++++++++++++++++++

3 files changed, 99 insertions(+)

create mode 100644 drivers/bus/imx-aipstz.c

diff --git a/drivers/bus/Kconfig b/drivers/bus/Kconfig

index XXXXXXX..XXXXXXX 100644

--- a/drivers/bus/Kconfig

+++ b/drivers/bus/Kconfig

@@ -XXX,XX +XXX,XX @@ config HISILICON_LPC

     Driver to enable I/O access to devices attached to the Low Pin

     Count bus on the HiSilicon Hip06/7 SoC.

+config IMX_AIPSTZ

+    tristate "Support for IMX Secure AHB to IP Slave bus (AIPSTZ) bridge"

+    depends on ARCH_MXC

+    help

+     Enable support for IMX AIPSTZ bridge.

+

config IMX_WEIM

    bool "Freescale EIM DRIVER"

    depends on ARCH_MXC || COMPILE_TEST

diff --git a/drivers/bus/Makefile b/drivers/bus/Makefile

index XXXXXXX..XXXXXXX 100644

--- a/drivers/bus/Makefile

+++ b/drivers/bus/Makefile

@@ -XXX,XX +XXX,XX @@ obj-$(CONFIG_FSL_MC_BUS)    += fsl-mc/

obj-$(CONFIG_BT1_APB)        += bt1-apb.o

obj-$(CONFIG_BT1_AXI)        += bt1-axi.o

+obj-$(CONFIG_IMX_AIPSTZ)    += imx-aipstz.o

obj-$(CONFIG_IMX_WEIM)        += imx-weim.o

obj-$(CONFIG_INTEL_IXP4XX_EB)    += intel-ixp4xx-eb.o

obj-$(CONFIG_MIPS_CDMM)        += mips_cdmm.o

diff --git a/drivers/bus/imx-aipstz.c b/drivers/bus/imx-aipstz.c

new file mode 100644

index XXXXXXX..XXXXXXX

--- /dev/null

+++ b/drivers/bus/imx-aipstz.c

@@ -XXX,XX +XXX,XX @@

+// SPDX-License-Identifier: GPL-2.0

+/*

+ * Copyright 2025 NXP

+ */

+

+#include <linux/module.h>

+#include <linux/of.h>

+#include <linux/of_platform.h>

+#include <linux/platform_device.h>

+#include <linux/pm_runtime.h>

+#include <linux/regmap.h>

+

+#define IMX_AIPSTZ_MPR0 0x0

+

+struct imx_aipstz_config {

+    u32 mpr0;

+};

+

+static void imx_aipstz_apply_default(void __iomem *base,

+                 const struct imx_aipstz_config *default_cfg)

+{

+    writel(default_cfg->mpr0, base + IMX_AIPSTZ_MPR0);

+}

+

+static int imx_aipstz_probe(struct platform_device *pdev)

+{

+    const struct imx_aipstz_config *default_cfg;

+    void __iomem *base;

+

+    base = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);

+    if (IS_ERR(base))

+        return dev_err_probe(&pdev->dev, -ENOMEM,

+                 "failed to get/ioremap AC memory\n");

+

+    default_cfg = of_device_get_match_data(&pdev->dev);

+

+    imx_aipstz_apply_default(base, default_cfg);

+

+    dev_set_drvdata(&pdev->dev, base);

+

+    pm_runtime_set_active(&pdev->dev);

+    devm_pm_runtime_enable(&pdev->dev);

+

+    return devm_of_platform_populate(&pdev->dev);

+}

+

+static int imx_aipstz_runtime_resume(struct device *dev)

+{

+    const struct imx_aipstz_config *default_cfg;

+    void __iomem *base;

+

+    base = dev_get_drvdata(dev);

+    default_cfg = of_device_get_match_data(dev);

+

+    /* restore potentially lost configuration during domain power-off */

+    imx_aipstz_apply_default(base, default_cfg);

+

+    return 0;

+}

+

+static const struct dev_pm_ops imx_aipstz_pm_ops = {

+    RUNTIME_PM_OPS(NULL, imx_aipstz_runtime_resume, NULL)

+    SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, pm_runtime_force_resume)

+};

+

+/*

+ * following configuration is equivalent to:

+ *    masters 0-7 => trusted for R/W + use AHB's HPROT[1] to det. privilege

+ */

+static const struct imx_aipstz_config imx8mp_aipstz_default_cfg = {

+    .mpr0 = 0x77777777,

+};

+

+static const struct of_device_id imx_aipstz_of_ids[] = {

+    { .compatible = "fsl,imx8mp-aipstz", .data = &imx8mp_aipstz_default_cfg },

+    { }

+};

+MODULE_DEVICE_TABLE(of, imx_aipstz_of_ids);

+

+static struct platform_driver imx_aipstz_of_driver = {

+    .probe = imx_aipstz_probe,

+    .driver = {

+        .name = "imx-aipstz",

+        .of_match_table = imx_aipstz_of_ids,

+        .pm = pm_ptr(&imx_aipstz_pm_ops),

+    },

+};

+module_platform_driver(imx_aipstz_of_driver);

+

+MODULE_LICENSE("GPL");

+MODULE_DESCRIPTION("IMX secure AHB to IP Slave bus (AIPSTZ) bridge driver");

+MODULE_AUTHOR("Laurentiu Mihalcea <laurentiu.mihalcea@nxp.com>");

--

2.34.1

From: Laurentiu Mihalcea <laurentiu.mihalcea@nxp.com>

AIPS5 is actually AIPSTZ5 as it offers some security-related

configurations. Since these configurations need to be applied before

accessing any of the peripherals on the bus, it's better to make AIPSTZ5

be their parent instead of keeping AIPS5 and adding a child node for

AIPSTZ5. Also, because of the security configurations, the address space

of the bus has to be changed to that of the configuration registers.

Finally, since AIPSTZ5 belongs to the AUDIOMIX power domain, add the

missing 'power-domains' property. The domain needs to be powered on before

attempting to configure the security-related registers.

The DT node name is not changed to avoid potential issues with DTs in

which this node is referenced.

Co-developed-by: Daniel Baluta <daniel.baluta@nxp.com>

Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com>

Signed-off-by: Laurentiu Mihalcea <laurentiu.mihalcea@nxp.com>

Reviewed-by: Frank Li <Frank.Li@nxp.com>

---

arch/arm64/boot/dts/freescale/imx8mp.dtsi | 10 ++++++----

1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/arch/arm64/boot/dts/freescale/imx8mp.dtsi b/arch/arm64/boot/dts/freescale/imx8mp.dtsi

index XXXXXXX..XXXXXXX 100644

--- a/arch/arm64/boot/dts/freescale/imx8mp.dtsi

+++ b/arch/arm64/boot/dts/freescale/imx8mp.dtsi

@@ -XXX,XX +XXX,XX @@ eqos: ethernet@30bf0000 {

            };

        };

-        aips5: bus@30c00000 {

-            compatible = "fsl,aips-bus", "simple-bus";

-            reg = <0x30c00000 0x400000>;

+        aips5: bus@30df0000 {

+            compatible = "fsl,imx8mp-aipstz";

+            reg = <0x30df0000 0x10000>;

+            power-domains = <&pgc_audio>;

            #address-cells = <1>;

            #size-cells = <1>;

-            ranges;

+            #access-controller-cells = <3>;

+            ranges = <0x30c00000 0x30c00000 0x400000>;

            spba-bus@30c00000 {

                compatible = "fsl,spba-bus", "simple-bus";

--

2.34.1