platform: tegra: Add mc_all central actmon driver

Actmon DFS for EMC has been moved to BPMP side. This driver simply reads
the exponential moving average counter register of the MC_ALL client and
export the value in the sysfs node to let tegrastats read the
utilization value of the EMC.

Bug 4041434

Signed-off-by: Johnny Liu <johnliu@nvidia.com>
Change-Id: I2b7e6592094d27c47f738fc26ee9091ea209f630
Reviewed-on: https://git-master.nvidia.com/r/c/linux-nv-oot/+/2912315
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>

drivers/platform/tegra/Makefile

@@ -8,6 +8,7 @@ obj-m += tegra-bootloader-debug.o
 tegra-cactmon-objs := cactmon.o
 tegra-cactmon-objs += actmon_common.o
 obj-m += tegra-cactmon.o
+obj-m += tegra-cactmon-mc-all.o
 obj-m += tegra-fsicom.o
 
 obj-m += mce/

drivers/platform/tegra/tegra-cactmon-mc-all.c

@@ -0,0 +1,153 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2023 NVIDIA CORPORATION.  All rights reserved.
+ */
+
+#include <linux/clk.h>
+#include <linux/debugfs.h>
+#include <linux/device.h>
+#include <linux/fs.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/types.h>
+
+#define	CENTRAL_ACTMON_CTRL_REG			0x0
+#define CENTRAL_ACTMON_MC_ALL_AVG_COUNT_REG	0x124
+#define CENTRAL_ACTMON_CTRL_SOURCE(v)		((v & (0x3 << 8)) >> 8)
+#define CENTRAL_ACTMON_CTRL_SAMPLE_TICK(v)	((v & (0x1 << 10)) >> 10)
+#define CENTRAL_ACTMON_CTRL_SAMPLE_PERIOD(v)	((v & (0xff << 0)) >> 0)
+
+struct central_actmon {
+	struct device *dev;
+	struct clk *clk;
+	unsigned long rate;
+	void __iomem *regs;
+	struct dentry *debugfs;
+};
+
+static u32 cactmon_readl(struct central_actmon *cactmon, u32 offset)
+{
+	return readl(cactmon->regs+offset);
+}
+
+static u32 __central_actmon_sample_period_get(struct central_actmon *cactmon)
+{
+	u32 val, source, sample_tick, sample_period;
+
+	val = cactmon_readl(cactmon, CENTRAL_ACTMON_CTRL_REG);
+
+	source = CENTRAL_ACTMON_CTRL_SOURCE(val);
+	sample_period = CENTRAL_ACTMON_CTRL_SAMPLE_PERIOD(val) + 1;
+
+	if (source == 1) {
+		sample_period *= 1;
+	} else if (source == 0) {
+		sample_period *= 1000;
+	} else {
+		sample_tick = CENTRAL_ACTMON_CTRL_SAMPLE_TICK(val);
+		sample_period *= sample_tick ? 65536 : 256;
+		sample_period = (sample_period * 1000) / (cactmon->rate / 1000);
+	}
+
+	return sample_period;
+}
+
+static int central_actmon_sample_period_get(void *data, u64 *val)
+{
+	struct central_actmon *cactmon = (struct central_actmon *)data;
+
+	*val = (u64) __central_actmon_sample_period_get(cactmon);
+
+	return 0;
+}
+
+DEFINE_SIMPLE_ATTRIBUTE(central_actmon_sample_period_fops,
+		central_actmon_sample_period_get, NULL,
+		"%lld\n");
+
+static int central_actmon_mc_all_get(void *data, u64 *val)
+{
+	struct central_actmon *cactmon = (struct central_actmon *)data;
+	u32 sample_period_usec, mc_all_actives;
+
+	sample_period_usec = __central_actmon_sample_period_get(cactmon);
+
+	mc_all_actives = cactmon_readl(cactmon, CENTRAL_ACTMON_MC_ALL_AVG_COUNT_REG);
+
+	*val = mc_all_actives * 1000 / sample_period_usec;
+
+	return 0;
+}
+
+DEFINE_SIMPLE_ATTRIBUTE(central_actmon_mc_all_fops,
+		central_actmon_mc_all_get, NULL,
+		"%lld\n");
+
+static void central_actmon_debugfs_init(struct central_actmon *cactmon)
+{
+	cactmon->debugfs = debugfs_create_dir("cactmon", NULL);
+
+	debugfs_create_file("sample_period_usec", 0444, cactmon->debugfs, cactmon,
+			    &central_actmon_sample_period_fops);
+	debugfs_create_file("mc_all", 0444, cactmon->debugfs, cactmon,
+			    &central_actmon_mc_all_fops);
+}
+
+static int central_actmon_probe(struct platform_device *pdev)
+{
+	struct central_actmon *cactmon;
+
+	cactmon = devm_kzalloc(&pdev->dev, sizeof(*cactmon), GFP_KERNEL);
+	if (!cactmon)
+		return -ENOMEM;
+
+	cactmon->regs = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
+	if (IS_ERR(cactmon->regs))
+		return PTR_ERR(cactmon->regs);
+
+	cactmon->clk = devm_clk_get(&pdev->dev, "actmon");
+	if (IS_ERR(cactmon->clk))
+		return dev_err_probe(&pdev->dev,
+				     PTR_ERR(cactmon->clk),
+				     "failed to get actmon clock\n");
+	cactmon->rate = clk_get_rate(cactmon->clk);
+
+	cactmon->dev = &pdev->dev;
+	platform_set_drvdata(pdev, cactmon);
+
+	central_actmon_debugfs_init(cactmon);
+
+	return 0;
+}
+
+static int central_actmon_remove(struct platform_device *pdev)
+{
+	struct central_actmon *cactmon = platform_get_drvdata(pdev);
+
+	debugfs_remove_recursive(cactmon->debugfs);
+
+	return 0;
+}
+
+
+static const struct of_device_id central_actmon_of_match[] = {
+	{ .compatible = "nvidia,tegra234-cactmon-mc-all", .data = NULL, },
+	{},
+};
+MODULE_DEVICE_TABLE(of, central_actmon_of_match);
+
+static struct platform_driver central_actmon_driver = {
+	.probe		= central_actmon_probe,
+	.remove		= central_actmon_remove,
+	.driver	= {
+		.name	= "tegra-cactmon-mc-all",
+		.owner	= THIS_MODULE,
+		.of_match_table = of_match_ptr(central_actmon_of_match),
+	},
+};
+module_platform_driver(central_actmon_driver);
+
+MODULE_DESCRIPTION("Tegra MC_ALL Central Activity Monitor");
+MODULE_AUTHOR("Johnny Liu <johnliu@nvidia.com>");
+MODULE_LICENSE("GPL v2");