hwpm: Makefile: Add support to make as module

Add support to make the HWPM driver as module.
Set appropriate path and environment variable
which needs to be passed when building the driver
as module.
Use basic fuse.h file instead of using fuse-helper.h which is not
available in OOT builds.
Introduce HWPM mock file to add definitions for register and
unregister used if HWPM is not compiled in a build.

Bug 4088571

Change-Id: Id6cfb78356d752b963ad7eb16e39b85df92a9a4b
Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Vedashree Vidwans <vvidwans@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/c/linux-hwpm/+/2894547
GVS: Gerrit_Virtual_Submit <buildbot_gerritrpt@nvidia.com>

drivers/Kconfig

@@ -0,0 +1,7 @@
+append_menu "Device Drivers"
+
+if ARCH_TEGRA
+source "drivers/tegra/hwpm/Kconfig"
+endif
+
+endmenu

drivers/Makefile

@@ -0,0 +1,5 @@
+# Copyright (c) 2022, NVIDIA CORPORATION. All rights reserved.
+
+subdir-ccflags-y += -Werror
+
+obj-y     +=	tegra/hwpm/

drivers/tegra/hwpm/Kconfig

@@ -1,3 +1,10 @@
+config TEGRA_SOC_HWPM
+	tristate "Tegra SOC HWPM driver"
+	default m
+	help
+	  The SOC HWPM driver enables performance monitoring for various Tegra
+	  IPs.
+
 config TEGRA_T234_HWPM
 	bool "Tegra T23x HWPM driver"
 	depends on TEGRA_SOC_HWPM && ARCH_TEGRA_23x_SOC

drivers/tegra/hwpm/Makefile

@@ -1,13 +1,21 @@
+# Copyright (c) 2022, NVIDIA CORPORATION. All rights reserved.
 #
 # Tegra SOC HWPM
 #
 
-# SPDX-License-Identifier: GPL-2.0
 GCOV_PROFILE := y
 
-ccflags-y += -I$(srctree.nvidia)/include
+ifeq ($(origin srctree.hwpm), undefined)
-ccflags-y += -I$(srctree.nvidia)/drivers/platform/tegra/hwpm/include
+srctree.hwpm := $(abspath $(shell dirname $(lastword $(MAKEFILE_LIST))))/../../..
-ccflags-y += -I$(srctree.nvidia)/drivers/platform/tegra/hwpm
+endif
+
+CONFIG_TEGRA_SOC_HWPM := y
+ccflags-y += -DCONFIG_TEGRA_SOC_HWPM
+
+CONFIG_TEGRA_T234_HWPM := y
+ccflags-y += -DCONFIG_TEGRA_T234_HWPM
+
+NVHWPM_OBJ = m
 
 # For OOT builds, set required config flags
 ifeq ($(CONFIG_TEGRA_OOT_MODULE),m)
@@ -17,26 +25,24 @@ ccflags-y += -DCONFIG_TEGRA_HWPM_OOT
 CONFIG_TEGRA_FUSE_UPSTREAM := y
 ccflags-y += -DCONFIG_TEGRA_FUSE_UPSTREAM
 
-CONFIG_TEGRA_T234_HWPM := y
+LINUXINCLUDE += -I$(srctree.hwpm)/include
-ccflags-y += -DCONFIG_TEGRA_T234_HWPM
+LINUXINCLUDE += -I$(srctree.hwpm)/drivers/tegra/hwpm/include
-NVHWPM_OBJ = m
+LINUXINCLUDE += -I$(srctree.hwpm)/drivers/tegra/hwpm
+
 else
-NVHWPM_OBJ = y
+ccflags-y += -I$(srctree.nvidia)/include
+ccflags-y += -I$(srctree.hwpm)/include
+ccflags-y += -I$(srctree.hwpm)/drivers/tegra/hwpm/include
+ccflags-y += -I$(srctree.hwpm)/drivers/tegra/hwpm
+
 endif
 
+ifeq ($(NV_BUILD_CONFIGURATION_IS_SAFETY),1)
+obj-${NVHWPM_OBJ} += tegra_hwpm_mock.o
+else
 # Add required objects to nvhwpm object variable
-# Include common files
+include $(srctree.hwpm)/drivers/tegra/hwpm/Makefile.sources
-include $(srctree.nvidia)/drivers/platform/tegra/hwpm/Makefile.common.sources
-nvhwpm-objs += ${nvhwpm-common-objs}
-
-# Include linux files
-include $(srctree.nvidia)/drivers/platform/tegra/hwpm/Makefile.linux.sources
-nvhwpm-objs += ${nvhwpm-linux-objs}
-
-ifeq ($(CONFIG_TEGRA_T234_HWPM),y)
-# Include T234 files
-include $(srctree.nvidia)/drivers/platform/tegra/hwpm/Makefile.t234.sources
-nvhwpm-objs += ${nvhwpm-t234-objs}
-endif
 
 obj-${NVHWPM_OBJ} += nvhwpm.o
+
+endif

drivers/tegra/hwpm/Makefile.sources

@@ -0,0 +1,18 @@
+# Copyright (c) 2023, NVIDIA CORPORATION. All rights reserved.
+#
+# Tegra SOC HWPM Sources
+#
+
+# Include common files
+include $(srctree.hwpm)/drivers/tegra/hwpm/Makefile.common.sources
+nvhwpm-objs += ${nvhwpm-common-objs}
+
+# Include linux files
+include $(srctree.hwpm)/drivers/tegra/hwpm/Makefile.linux.sources
+nvhwpm-objs += ${nvhwpm-linux-objs}
+
+ifeq ($(CONFIG_TEGRA_T234_HWPM),y)
+# Include T234 files
+include $(srctree.hwpm)/drivers/tegra/hwpm/Makefile.t234.sources
+nvhwpm-objs += ${nvhwpm-t234-objs}
+endif

drivers/tegra/hwpm/os/linux/soc_utils.c

@@ -18,7 +18,7 @@
 #if CONFIG_ACPI
 #include <linux/acpi.h>
 #endif
-#include <soc/tegra/fuse-helper.h>
+#include <soc/tegra/fuse.h>
 
 #include <tegra_hwpm_log.h>
 #include <tegra_hwpm_soc.h>

drivers/tegra/hwpm/tegra_hwpm_mock.c

@@ -0,0 +1,55 @@
+/*
+ * Copyright (c) 2023, NVIDIA CORPORATION.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/export.h>
+#include <linux/module.h>
+#include <uapi/linux/tegra-soc-hwpm-uapi.h>
+#include <os/linux/driver.h>
+
+void tegra_soc_hwpm_ip_register(struct tegra_soc_hwpm_ip_ops *hwpm_ip_ops)
+{
+	/* Dummy function */
+}
+EXPORT_SYMBOL(tegra_soc_hwpm_ip_register);
+
+void tegra_soc_hwpm_ip_unregister(struct tegra_soc_hwpm_ip_ops *hwpm_ip_ops)
+{
+	/* Dummy function */
+}
+EXPORT_SYMBOL(tegra_soc_hwpm_ip_unregister);
+
+
+/* Dummy implementation for module */
+static int __init tegra_hwpm_init(void)
+{
+        return 0;
+}
+
+static void __exit tegra_hwpm_exit(void)
+{
+}
+
+#if defined(CONFIG_TEGRA_HWPM_OOT)
+module_init(tegra_hwpm_init);
+#else
+postcore_initcall(tegra_hwpm_init);
+#endif
+module_exit(tegra_hwpm_exit);
+
+MODULE_ALIAS(TEGRA_SOC_HWPM_MODULE_NAME);
+MODULE_DESCRIPTION("Tegra SOC HWPM MOCK Driver");
+MODULE_LICENSE("GPL v2");
+