memory: tegra: Add driver or smmu-hwpm interface

Bug 4704679

Change-Id: If02ceec6c4b147fe76f578eba678c35500e381ba
Signed-off-by: Ashish Mhetre <amhetre@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/c/linux-t264/+/3186439
Reviewed-by: Ketan Patil <ketanp@nvidia.com>
Reviewed-by: Pritesh Raithatha <praithatha@nvidia.com>
GVS: buildbot_gerritrpt <buildbot_gerritrpt@nvidia.com>

drivers/memory/tegra/private-soc/Makefile

@@ -1,4 +1,5 @@
 # SPDX-License-Identifier: GPL-2.0
 obj-m += mc-t26x.o
 obj-m += tegra264-mc-hwpm.o
+obj-m += smmu-hwpm.o
 obj-m += mem-qual.o

drivers/memory/tegra/private-soc/smmu-hwpm.c

@@ -0,0 +1,138 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2024, NVIDIA CORPORATION.  All rights reserved.
+ */
+
+#define pr_fmt(fmt) "smmu-hwpm: " fmt
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/export.h>
+#include <linux/of_device.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+
+#include <uapi/linux/tegra-soc-hwpm-uapi.h>
+
+#define SMMU_TCU_PERFMUX_0_OFFSET	0x5000
+
+static struct tegra_soc_hwpm_ip_ops hwpm_ip_ops;
+
+struct smmu_hwpm {
+	struct device *dev;
+	void __iomem *base;
+};
+
+static u32 smmu_readl(struct smmu_hwpm *smmu, u32 reg)
+{
+	return readl(smmu->base + reg);
+}
+
+static void smmu_writel(struct smmu_hwpm *smmu, u32 val, u32 reg)
+{
+	writel(val, smmu->base + reg);
+}
+
+static int smmu_hwpm_reg_op(void *ip_dev,
+	enum tegra_soc_hwpm_ip_reg_op reg_op,
+	u32 inst_element_index, u64 reg_offset, u32 *reg_data)
+{
+	struct device *dev = (struct device *)ip_dev;
+	struct smmu_hwpm *smmu;
+
+	smmu = dev_get_drvdata(dev);
+	if (!smmu) {
+		pr_err("Invalid device\n");
+		return -ENODEV;
+	}
+
+	if ((u32)reg_offset != SMMU_TCU_PERFMUX_0_OFFSET) {
+		dev_err(smmu->dev, "SOC-HWPM requesting access to prohibited register");
+		return -EPERM;
+	}
+
+	if (reg_op == TEGRA_SOC_HWPM_IP_REG_OP_READ) {
+		*reg_data = smmu_readl(smmu, (u32)reg_offset);
+	} else if (reg_op == TEGRA_SOC_HWPM_IP_REG_OP_WRITE) {
+		smmu_writel(smmu, *reg_data, (u32)reg_offset);
+	} else {
+		dev_err(smmu->dev, "Invalid operation\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static const struct of_device_id smmu_hwpm_of_ids[] = {
+	{ .compatible = "nvidia,t264-smmu-hwpm" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, smmu_hwpm_of_ids);
+
+static int smmu_hwpm_probe(struct platform_device *pdev)
+{
+	struct smmu_hwpm *smmu;
+	struct resource *res;
+	u64 base_addr;
+
+	smmu = devm_kzalloc(&pdev->dev, sizeof(*smmu), GFP_KERNEL);
+	if (!smmu)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, smmu);
+	smmu->dev = &pdev->dev;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(smmu->dev, "Missing SMMU aperture in DT\n");
+		return -ENODEV;
+	}
+
+	smmu->base = devm_ioremap(smmu->dev, res->start, resource_size(res));
+	if (IS_ERR_OR_NULL(smmu->base))
+		return PTR_ERR(smmu->base);
+
+	base_addr = res->start;
+
+	hwpm_ip_ops.ip_dev = (void *)smmu->dev;
+	hwpm_ip_ops.resource_enum = TEGRA_SOC_HWPM_RESOURCE_SMMU;
+	hwpm_ip_ops.ip_base_address = base_addr;
+	hwpm_ip_ops.hwpm_ip_reg_op = &smmu_hwpm_reg_op;
+	tegra_soc_hwpm_ip_register(&hwpm_ip_ops);
+
+	return 0;
+}
+
+static int smmu_hwpm_remove(struct platform_device *pdev)
+{
+	tegra_soc_hwpm_ip_unregister(&hwpm_ip_ops);
+	return 0;
+}
+
+static struct platform_driver smmu_hwpm_driver = {
+	.driver = {
+		.name	= "tegra264-smmu-hwpm",
+		.of_match_table = smmu_hwpm_of_ids,
+		.owner	= THIS_MODULE,
+	},
+
+	.probe		= smmu_hwpm_probe,
+	.remove		= smmu_hwpm_remove,
+};
+
+static int __init smmu_hwpm_init(void)
+{
+	return platform_driver_register(&smmu_hwpm_driver);
+}
+module_init(smmu_hwpm_init);
+
+static void __exit smmu_hwpm_exit(void)
+{
+	platform_driver_unregister(&smmu_hwpm_driver);
+}
+module_exit(smmu_hwpm_exit);
+
+MODULE_AUTHOR("Ashish Mhetre <amhetre@nvidia.com>");
+MODULE_DESCRIPTION("Tegra264 SMMU-HWPM driver");
+MODULE_LICENSE("GPL v2");