of/overlay: Add overlay unittests

Add unittests for OF overlays.

It tests overlay device addition/removal and whether
the apply revert sequence is correct.

Changes since V1:
* Added local fixups entries.

Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
Signed-off-by: Grant Likely <grant.likely@linaro.org>

4 files changed, 691 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/unittest.txt b/Documentation/devicetree/bindings/unittest.txt
new file mode 100644
index 000000000000..0f92a22fddfa
--- /dev/null
+++ b/Documentation/devicetree/bindings/unittest.txt
@@ -0,0 +1,14 @@
+* OF selftest platform device
+
+** selftest
+
+Required properties:
+- compatible: must be "selftest"
+
+All other properties are optional.
+
+Example:
+        selftest {
+                compatible = "selftest";
+                status = "okay";
+        };
diff --git a/drivers/of/unittest-data/testcases.dts b/drivers/of/unittest-data/testcases.dts
index b6bc41b2a185..12f7c3d649c8 100644
--- a/drivers/of/unittest-data/testcases.dts
+++ b/drivers/of/unittest-data/testcases.dts
@@ -13,6 +13,7 @@
 #include "tests-interrupts.dtsi"
 #include "tests-match.dtsi"
 #include "tests-platform.dtsi"
+#include "tests-overlay.dtsi"
 
 /*
  * phandle fixup data - generated by dtc patches that aren't upstream.
@@ -59,5 +60,20 @@
                 testcase-device2 {
                         interrupt-parent = <0x00000000>;
                 };
+                overlay2 {
+                        fragment@0 {
+                                target = <0x00000000>;
+                        };
+                };
+                overlay3 {
+                        fragment@0 {
+                                target = <0x00000000>;
+                        };
+                };
+                overlay4 {
+                        fragment@0 {
+                                target = <0x00000000>;
+                        };
+                };
         };
 }; };
diff --git a/drivers/of/unittest-data/tests-overlay.dtsi b/drivers/of/unittest-data/tests-overlay.dtsi
new file mode 100644
index 000000000000..75976da22b2e
--- /dev/null
+++ b/drivers/of/unittest-data/tests-overlay.dtsi
@@ -0,0 +1,180 @@
+
+/ {
+        testcase-data {
+                overlay-node {
+
+                        /* test bus */
+                        selftestbus: test-bus {
+                                compatible = "simple-bus";
+                                #address-cells = <1>;
+                                #size-cells = <0>;
+
+                                selftest100: test-selftest100 {
+                                        compatible = "selftest";
+                                        status = "okay";
+                                        reg = <100>;
+                                };
+
+                                selftest101: test-selftest101 {
+                                        compatible = "selftest";
+                                        status = "disabled";
+                                        reg = <101>;
+                                };
+
+                                selftest0: test-selftest0 {
+                                        compatible = "selftest";
+                                        status = "disabled";
+                                        reg = <0>;
+                                };
+
+                                selftest1: test-selftest1 {
+                                        compatible = "selftest";
+                                        status = "okay";
+                                        reg = <1>;
+                                };
+
+                                selftest2: test-selftest2 {
+                                        compatible = "selftest";
+                                        status = "disabled";
+                                        reg = <2>;
+                                };
+
+                                selftest3: test-selftest3 {
+                                        compatible = "selftest";
+                                        status = "okay";
+                                        reg = <3>;
+                                };
+
+                                selftest5: test-selftest5 {
+                                        compatible = "selftest";
+                                        status = "disabled";
+                                        reg = <5>;
+                                };
+
+                                selftest6: test-selftest6 {
+                                        compatible = "selftest";
+                                        status = "disabled";
+                                        reg = <6>;
+                                };
+
+                                selftest7: test-selftest7 {
+                                        compatible = "selftest";
+                                        status = "disabled";
+                                        reg = <7>;
+                                };
+
+                                selftest8: test-selftest8 {
+                                        compatible = "selftest";
+                                        status = "disabled";
+                                        reg = <8>;
+                                };
+                        };
+                };
+
+                /* test enable using absolute target path */
+                overlay0 {
+                        fragment@0 {
+                                target-path = "/testcase-data/overlay-node/test-bus/test-selftest0";
+                                __overlay__ {
+                                        status = "okay";
+                                };
+                        };
+                };
+
+                /* test disable using absolute target path */
+                overlay1 {
+                        fragment@0 {
+                                target-path = "/testcase-data/overlay-node/test-bus/test-selftest1";
+                                __overlay__ {
+                                        status = "disabled";
+                                };
+                        };
+                };
+
+                /* test enable using label */
+                overlay2 {
+                        fragment@0 {
+                                target = <&selftest2>;
+                                __overlay__ {
+                                        status = "okay";
+                                };
+                        };
+                };
+
+                /* test disable using label */
+                overlay3 {
+                        fragment@0 {
+                                target = <&selftest3>;
+                                __overlay__ {
+                                        status = "disabled";
+                                };
+                        };
+                };
+
+                /* test insertion of a full node */
+                overlay4 {
+                        fragment@0 {
+                                target = <&selftestbus>;
+                                __overlay__ {
+
+                                        /* suppress DTC warning */
+                                        #address-cells = <1>;
+                                        #size-cells = <0>;
+
+                                        test-selftest4 {
+                                                compatible = "selftest";
+                                                status = "okay";
+                                                reg = <4>;
+                                        };
+                                };
+                        };
+                };
+
+                /* test overlay apply revert */
+                overlay5 {
+                        fragment@0 {
+                                target-path = "/testcase-data/overlay-node/test-bus/test-selftest5";
+                                __overlay__ {
+                                        status = "okay";
+                                };
+                        };
+                };
+
+                /* test overlays application and removal in sequence */
+                overlay6 {
+                        fragment@0 {
+                                target-path = "/testcase-data/overlay-node/test-bus/test-selftest6";
+                                __overlay__ {
+                                        status = "okay";
+                                };
+                        };
+                };
+                overlay7 {
+                        fragment@0 {
+                                target-path = "/testcase-data/overlay-node/test-bus/test-selftest7";
+                                __overlay__ {
+                                        status = "okay";
+                                };
+                        };
+                };
+
+                /* test overlays application and removal in bad sequence */
+                overlay8 {
+                        fragment@0 {
+                                target-path = "/testcase-data/overlay-node/test-bus/test-selftest8";
+                                __overlay__ {
+                                        status = "okay";
+                                };
+                        };
+                };
+                overlay9 {
+                        fragment@0 {
+                                target-path = "/testcase-data/overlay-node/test-bus/test-selftest8";
+                                __overlay__ {
+                                        property-foo = "bar";
+                                };
+                        };
+                };
+
+        };
+};
diff --git a/drivers/of/unittest.c b/drivers/of/unittest.c
index 1720b039cac7..cc0c5ec5d464 100644
--- a/drivers/of/unittest.c
+++ b/drivers/of/unittest.c
@@ -17,6 +17,8 @@
 #include <linux/mutex.h>
 #include <linux/slab.h>
 #include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/of_platform.h>
 
 #include "of_private.h"
 
@@ -933,6 +935,484 @@ static void selftest_data_remove(void)
         }
 }
 
+#ifdef CONFIG_OF_OVERLAY
+
+static int selftest_probe(struct platform_device *pdev)
+{
+        struct device *dev = &pdev->dev;
+        struct device_node *np = dev->of_node;
+
+        if (np == NULL) {
+                dev_err(dev, "No OF data for device\n");
+                return -EINVAL;
+
+        }
+
+        dev_dbg(dev, "%s for node @%s\n", __func__, np->full_name);
+        return 0;
+}
+
+static int selftest_remove(struct platform_device *pdev)
+{
+        struct device *dev = &pdev->dev;
+        struct device_node *np = dev->of_node;
+
+        dev_dbg(dev, "%s for node @%s\n", __func__, np->full_name);
+        return 0;
+}
+
+static struct of_device_id selftest_match[] = {
+        { .compatible = "selftest", },
+        {},
+};
+MODULE_DEVICE_TABLE(of, altera_jtaguart_match);
+
+static struct platform_driver selftest_driver = {
+        .probe                  = selftest_probe,
+        .remove                 = selftest_remove,
+        .driver = {
+                .name           = "selftest",
+                .owner          = THIS_MODULE,
+                .of_match_table = of_match_ptr(selftest_match),
+        },
+};
+
+/* get the platform device instantiated at the path */
+static struct platform_device *of_path_to_platform_device(const char *path)
+{
+        struct device_node *np;
+        struct platform_device *pdev;
+
+        np = of_find_node_by_path(path);
+        if (np == NULL)
+                return NULL;
+
+        pdev = of_find_device_by_node(np);
+        of_node_put(np);
+
+        return pdev;
+}
+
+/* find out if a platform device exists at that path */
+static int of_path_platform_device_exists(const char *path)
+{
+        struct platform_device *pdev;
+
+        pdev = of_path_to_platform_device(path);
+        platform_device_put(pdev);
+        return pdev != NULL;
+}
+
+static const char *selftest_path(int nr)
+{
+        static char buf[256];
+
+        snprintf(buf, sizeof(buf) - 1,
+                "/testcase-data/overlay-node/test-bus/test-selftest%d", nr);
+        buf[sizeof(buf) - 1] = '\0';
+
+        return buf;
+}
+
+static const char *overlay_path(int nr)
+{
+        static char buf[256];
+
+        snprintf(buf, sizeof(buf) - 1,
+                "/testcase-data/overlay%d", nr);
+        buf[sizeof(buf) - 1] = '\0';
+
+        return buf;
+}
+
+static const char *bus_path = "/testcase-data/overlay-node/test-bus";
+
+static int of_selftest_apply_overlay(int selftest_nr, int overlay_nr,
+                int *overlay_id)
+{
+        struct device_node *np = NULL;
+        int ret, id = -1;
+
+        np = of_find_node_by_path(overlay_path(overlay_nr));
+        if (np == NULL) {
+                selftest(0, "could not find overlay node @\"%s\"\n",
+                                overlay_path(overlay_nr));
+                ret = -EINVAL;
+                goto out;
+        }
+
+        ret = of_overlay_create(np);
+        if (ret < 0) {
+                selftest(0, "could not create overlay from \"%s\"\n",
+                                overlay_path(overlay_nr));
+                goto out;
+        }
+        id = ret;
+
+        ret = 0;
+
+out:
+        of_node_put(np);
+
+        if (overlay_id)
+                *overlay_id = id;
+
+        return ret;
+}
+
+/* apply an overlay while checking before and after states */
+static int of_selftest_apply_overlay_check(int overlay_nr, int selftest_nr,
+                int before, int after)
+{
+        int ret;
+
+        /* selftest device must not be in before state */
+        if (of_path_platform_device_exists(selftest_path(selftest_nr))
+                        != before) {
+                selftest(0, "overlay @\"%s\" with device @\"%s\" %s\n",
+                                overlay_path(overlay_nr),
+                                selftest_path(selftest_nr),
+                                !before ? "enabled" : "disabled");
+                return -EINVAL;
+        }
+
+        ret = of_selftest_apply_overlay(overlay_nr, selftest_nr, NULL);
+        if (ret != 0) {
+                /* of_selftest_apply_overlay already called selftest() */
+                return ret;
+        }
+
+        /* selftest device must be to set to after state */
+        if (of_path_platform_device_exists(selftest_path(selftest_nr))
+                        != after) {
+                selftest(0, "overlay @\"%s\" failed to create @\"%s\" %s\n",
+                                overlay_path(overlay_nr),
+                                selftest_path(selftest_nr),
+                                !after ? "enabled" : "disabled");
+                return -EINVAL;
+        }
+
+        return 0;
+}
+
+/* apply an overlay and then revert it while checking before, after states */
+static int of_selftest_apply_revert_overlay_check(int overlay_nr,
+                int selftest_nr, int before, int after)
+{
+        int ret, ov_id;
+
+        /* selftest device must be in before state */
+        if (of_path_platform_device_exists(selftest_path(selftest_nr))
+                        != before) {
+                selftest(0, "overlay @\"%s\" with device @\"%s\" %s\n",
+                                overlay_path(overlay_nr),
+                                selftest_path(selftest_nr),
+                                !before ? "enabled" : "disabled");
+                return -EINVAL;
+        }
+
+        /* apply the overlay */
+        ret = of_selftest_apply_overlay(overlay_nr, selftest_nr, &ov_id);
+        if (ret != 0) {
+                /* of_selftest_apply_overlay already called selftest() */
+                return ret;
+        }
+
+        /* selftest device must be in after state */
+        if (of_path_platform_device_exists(selftest_path(selftest_nr))
+                        != after) {
+                selftest(0, "overlay @\"%s\" failed to create @\"%s\" %s\n",
+                                overlay_path(overlay_nr),
+                                selftest_path(selftest_nr),
+                                !after ? "enabled" : "disabled");
+                return -EINVAL;
+        }
+
+        ret = of_overlay_destroy(ov_id);
+        if (ret != 0) {
+                selftest(0, "overlay @\"%s\" failed to be destroyed @\"%s\"\n",
+                                overlay_path(overlay_nr),
+                                selftest_path(selftest_nr));
+                return ret;
+        }
+
+        /* selftest device must be again in before state */
+        if (of_path_platform_device_exists(selftest_path(selftest_nr))
+                        != before) {
+                selftest(0, "overlay @\"%s\" with device @\"%s\" %s\n",
+                                overlay_path(overlay_nr),
+                                selftest_path(selftest_nr),
+                                !before ? "enabled" : "disabled");
+                return -EINVAL;
+        }
+
+        return 0;
+}
+
+/* test activation of device */
+static void of_selftest_overlay_0(void)
+{
+        int ret;
+
+        /* device should enable */
+        ret = of_selftest_apply_overlay_check(0, 0, 0, 1);
+        if (ret != 0)
+                return;
+
+        selftest(1, "overlay test %d passed\n", 0);
+}
+
+/* test deactivation of device */
+static void of_selftest_overlay_1(void)
+{
+        int ret;
+
+        /* device should disable */
+        ret = of_selftest_apply_overlay_check(1, 1, 1, 0);
+        if (ret != 0)
+                return;
+
+        selftest(1, "overlay test %d passed\n", 1);
+}
+
+/* test activation of device */
+static void of_selftest_overlay_2(void)
+{
+        int ret;
+
+        /* device should enable */
+        ret = of_selftest_apply_overlay_check(2, 2, 0, 1);
+        if (ret != 0)
+                return;
+
+        selftest(1, "overlay test %d passed\n", 2);
+}
+
+/* test deactivation of device */
+static void of_selftest_overlay_3(void)
+{
+        int ret;
+
+        /* device should disable */
+        ret = of_selftest_apply_overlay_check(3, 3, 1, 0);
+        if (ret != 0)
+                return;
+
+        selftest(1, "overlay test %d passed\n", 3);
+}
+
+/* test activation of a full device node */
+static void of_selftest_overlay_4(void)
+{
+        int ret;
+
+        /* device should disable */
+        ret = of_selftest_apply_overlay_check(4, 4, 0, 1);
+        if (ret != 0)
+                return;
+
+        selftest(1, "overlay test %d passed\n", 4);
+}
+
+/* test overlay apply/revert sequence */
+static void of_selftest_overlay_5(void)
+{
+        int ret;
+
+        /* device should disable */
+        ret = of_selftest_apply_revert_overlay_check(5, 5, 0, 1);
+        if (ret != 0)
+                return;
+
+        selftest(1, "overlay test %d passed\n", 5);
+}
+
+/* test overlay application in sequence */
+static void of_selftest_overlay_6(void)
+{
+        struct device_node *np;
+        int ret, i, ov_id[2];
+        int overlay_nr = 6, selftest_nr = 6;
+        int before = 0, after = 1;
+
+        /* selftest device must be in before state */
+        for (i = 0; i < 2; i++) {
+                if (of_path_platform_device_exists(
+                                        selftest_path(selftest_nr + i))
+                                != before) {
+                        selftest(0, "overlay @\"%s\" with device @\"%s\" %s\n",
+                                        overlay_path(overlay_nr + i),
+                                        selftest_path(selftest_nr + i),
+                                        !before ? "enabled" : "disabled");
+                        return;
+                }
+        }
+
+        /* apply the overlays */
+        for (i = 0; i < 2; i++) {
+
+                np = of_find_node_by_path(overlay_path(overlay_nr + i));
+                if (np == NULL) {
+                        selftest(0, "could not find overlay node @\"%s\"\n",
+                                        overlay_path(overlay_nr + i));
+                        return;
+                }
+
+                ret = of_overlay_create(np);
+                if (ret < 0)  {
+                        selftest(0, "could not create overlay from \"%s\"\n",
+                                        overlay_path(overlay_nr + i));
+                        return;
+                }
+                ov_id[i] = ret;
+        }
+
+        for (i = 0; i < 2; i++) {
+                /* selftest device must be in after state */
+                if (of_path_platform_device_exists(
+                                        selftest_path(selftest_nr + i))
+                                != after) {
+                        selftest(0, "overlay @\"%s\" failed @\"%s\" %s\n",
+                                        overlay_path(overlay_nr + i),
+                                        selftest_path(selftest_nr + i),
+                                        !after ? "enabled" : "disabled");
+                        return;
+                }
+        }
+
+        for (i = 1; i >= 0; i--) {
+                ret = of_overlay_destroy(ov_id[i]);
+                if (ret != 0) {
+                        selftest(0, "overlay @\"%s\" failed destroy @\"%s\"\n",
+                                        overlay_path(overlay_nr + i),
+                                        selftest_path(selftest_nr + i));
+                        return;
+                }
+        }
+
+        for (i = 0; i < 2; i++) {
+                /* selftest device must be again in before state */
+                if (of_path_platform_device_exists(
+                                        selftest_path(selftest_nr + i))
+                                != before) {
+                        selftest(0, "overlay @\"%s\" with device @\"%s\" %s\n",
+                                        overlay_path(overlay_nr + i),
+                                        selftest_path(selftest_nr + i),
+                                        !before ? "enabled" : "disabled");
+                        return;
+                }
+        }
+
+        selftest(1, "overlay test %d passed\n", 6);
+}
+
+/* test overlay application in sequence */
+static void of_selftest_overlay_8(void)
+{
+        struct device_node *np;
+        int ret, i, ov_id[2];
+        int overlay_nr = 8, selftest_nr = 8;
+
+        /* we don't care about device state in this test */
+
+        /* apply the overlays */
+        for (i = 0; i < 2; i++) {
+
+                np = of_find_node_by_path(overlay_path(overlay_nr + i));
+                if (np == NULL) {
+                        selftest(0, "could not find overlay node @\"%s\"\n",
+                                        overlay_path(overlay_nr + i));
+                        return;
+                }
+
+                ret = of_overlay_create(np);
+                if (ret < 0)  {
+                        selftest(0, "could not create overlay from \"%s\"\n",
+                                        overlay_path(overlay_nr + i));
+                        return;
+                }
+                ov_id[i] = ret;
+        }
+
+        /* now try to remove first overlay (it should fail) */
+        ret = of_overlay_destroy(ov_id[0]);
+        if (ret == 0) {
+                selftest(0, "overlay @\"%s\" was destroyed @\"%s\"\n",
+                                overlay_path(overlay_nr + 0),
+                                selftest_path(selftest_nr));
+                return;
+        }
+
+        /* removing them in order should work */
+        for (i = 1; i >= 0; i--) {
+                ret = of_overlay_destroy(ov_id[i]);
+                if (ret != 0) {
+                        selftest(0, "overlay @\"%s\" not destroyed @\"%s\"\n",
+                                        overlay_path(overlay_nr + i),
+                                        selftest_path(selftest_nr));
+                        return;
+                }
+        }
+
+        selftest(1, "overlay test %d passed\n", 8);
+}
+
+static void __init of_selftest_overlay(void)
+{
+        struct device_node *bus_np = NULL;
+        int ret;
+
+        ret = platform_driver_register(&selftest_driver);
+        if (ret != 0) {
+                selftest(0, "could not register selftest driver\n");
+                goto out;
+        }
+
+        bus_np = of_find_node_by_path(bus_path);
+        if (bus_np == NULL) {
+                selftest(0, "could not find bus_path \"%s\"\n", bus_path);
+                goto out;
+        }
+
+        ret = of_platform_populate(bus_np, of_default_bus_match_table,
+                        NULL, NULL);
+        if (ret != 0) {
+                selftest(0, "could not populate bus @ \"%s\"\n", bus_path);
+                goto out;
+        }
+
+        if (!of_path_platform_device_exists(selftest_path(100))) {
+                selftest(0, "could not find selftest0 @ \"%s\"\n",
+                                selftest_path(100));
+                goto out;
+        }
+
+        if (of_path_platform_device_exists(selftest_path(101))) {
+                selftest(0, "selftest1 @ \"%s\" should not exist\n",
+                                selftest_path(101));
+                goto out;
+        }
+
+        selftest(1, "basic infrastructure of overlays passed");
+
+        /* tests in sequence */
+        of_selftest_overlay_0();
+        of_selftest_overlay_1();
+        of_selftest_overlay_2();
+        of_selftest_overlay_3();
+        of_selftest_overlay_4();
+        of_selftest_overlay_5();
+        of_selftest_overlay_6();
+        of_selftest_overlay_8();
+
+out:
+        of_node_put(bus_np);
+}
+
+#else
+static inline void __init of_selftest_overlay(void) { }
+#endif
+
 static int __init of_selftest(void)
 {
         struct device_node *np;
@@ -965,6 +1445,7 @@ static int __init of_selftest(void)
         of_selftest_parse_interrupts_extended();
         of_selftest_match_node();
         of_selftest_platform_populate();
+        of_selftest_overlay();
 
         /* removing selftest data from live tree */
         selftest_data_remove();