Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 200 insertions, 0 deletions

diff --git a/drivers/char/hw_random/mtk-rng.c b/drivers/char/hw_random/mtk-rng.c
new file mode 100644
index 000000000..6c00ea008
--- /dev/null
+++ b/drivers/char/hw_random/mtk-rng.c
@@ -0,0 +1,200 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Driver for Mediatek Hardware Random Number Generator
+ *
+ * Copyright (C) 2017 Sean Wang <sean.wang@mediatek.com>
+ */
+#define MTK_RNG_DEV KBUILD_MODNAME
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/hw_random.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+
+/* Runtime PM autosuspend timeout: */
+#define RNG_AUTOSUSPEND_TIMEOUT		100
+
+#define USEC_POLL			2
+#define TIMEOUT_POLL			20
+
+#define RNG_CTRL			0x00
+#define RNG_EN				BIT(0)
+#define RNG_READY			BIT(31)
+
+#define RNG_DATA			0x08
+
+#define to_mtk_rng(p)	container_of(p, struct mtk_rng, rng)
+
+struct mtk_rng {
+	void __iomem *base;
+	struct clk *clk;
+	struct hwrng rng;
+};
+
+static int mtk_rng_init(struct hwrng *rng)
+{
+	struct mtk_rng *priv = to_mtk_rng(rng);
+	u32 val;
+	int err;
+
+	err = clk_prepare_enable(priv->clk);
+	if (err)
+		return err;
+
+	val = readl(priv->base + RNG_CTRL);
+	val |= RNG_EN;
+	writel(val, priv->base + RNG_CTRL);
+
+	return 0;
+}
+
+static void mtk_rng_cleanup(struct hwrng *rng)
+{
+	struct mtk_rng *priv = to_mtk_rng(rng);
+	u32 val;
+
+	val = readl(priv->base + RNG_CTRL);
+	val &= ~RNG_EN;
+	writel(val, priv->base + RNG_CTRL);
+
+	clk_disable_unprepare(priv->clk);
+}
+
+static bool mtk_rng_wait_ready(struct hwrng *rng, bool wait)
+{
+	struct mtk_rng *priv = to_mtk_rng(rng);
+	int ready;
+
+	ready = readl(priv->base + RNG_CTRL) & RNG_READY;
+	if (!ready && wait)
+		readl_poll_timeout_atomic(priv->base + RNG_CTRL, ready,
+					  ready & RNG_READY, USEC_POLL,
+					  TIMEOUT_POLL);
+	return !!ready;
+}
+
+static int mtk_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait)
+{
+	struct mtk_rng *priv = to_mtk_rng(rng);
+	int retval = 0;
+
+	pm_runtime_get_sync((struct device *)priv->rng.priv);
+
+	while (max >= sizeof(u32)) {
+		if (!mtk_rng_wait_ready(rng, wait))
+			break;
+
+		*(u32 *)buf = readl(priv->base + RNG_DATA);
+		retval += sizeof(u32);
+		buf += sizeof(u32);
+		max -= sizeof(u32);
+	}
+
+	pm_runtime_mark_last_busy((struct device *)priv->rng.priv);
+	pm_runtime_put_sync_autosuspend((struct device *)priv->rng.priv);
+
+	return retval || !wait ? retval : -EIO;
+}
+
+static int mtk_rng_probe(struct platform_device *pdev)
+{
+	int ret;
+	struct mtk_rng *priv;
+
+	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->rng.name = pdev->name;
+#ifndef CONFIG_PM
+	priv->rng.init = mtk_rng_init;
+	priv->rng.cleanup = mtk_rng_cleanup;
+#endif
+	priv->rng.read = mtk_rng_read;
+	priv->rng.priv = (unsigned long)&pdev->dev;
+	priv->rng.quality = 900;
+
+	priv->clk = devm_clk_get(&pdev->dev, "rng");
+	if (IS_ERR(priv->clk)) {
+		ret = PTR_ERR(priv->clk);
+		dev_err(&pdev->dev, "no clock for device: %d\n", ret);
+		return ret;
+	}
+
+	priv->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(priv->base))
+		return PTR_ERR(priv->base);
+
+	ret = devm_hwrng_register(&pdev->dev, &priv->rng);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to register rng device: %d\n",
+			ret);
+		return ret;
+	}
+
+	dev_set_drvdata(&pdev->dev, priv);
+	pm_runtime_set_autosuspend_delay(&pdev->dev, RNG_AUTOSUSPEND_TIMEOUT);
+	pm_runtime_use_autosuspend(&pdev->dev);
+	pm_runtime_enable(&pdev->dev);
+
+	dev_info(&pdev->dev, "registered RNG driver\n");
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int mtk_rng_runtime_suspend(struct device *dev)
+{
+	struct mtk_rng *priv = dev_get_drvdata(dev);
+
+	mtk_rng_cleanup(&priv->rng);
+
+	return 0;
+}
+
+static int mtk_rng_runtime_resume(struct device *dev)
+{
+	struct mtk_rng *priv = dev_get_drvdata(dev);
+
+	return mtk_rng_init(&priv->rng);
+}
+
+static const struct dev_pm_ops mtk_rng_pm_ops = {
+	SET_RUNTIME_PM_OPS(mtk_rng_runtime_suspend,
+			   mtk_rng_runtime_resume, NULL)
+	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
+				pm_runtime_force_resume)
+};
+
+#define MTK_RNG_PM_OPS (&mtk_rng_pm_ops)
+#else	/* CONFIG_PM */
+#define MTK_RNG_PM_OPS NULL
+#endif	/* CONFIG_PM */
+
+static const struct of_device_id mtk_rng_match[] = {
+	{ .compatible = "mediatek,mt7623-rng" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, mtk_rng_match);
+
+static struct platform_driver mtk_rng_driver = {
+	.probe          = mtk_rng_probe,
+	.driver = {
+		.name = MTK_RNG_DEV,
+		.pm = MTK_RNG_PM_OPS,
+		.of_match_table = mtk_rng_match,
+	},
+};
+
+module_platform_driver(mtk_rng_driver);
+
+MODULE_DESCRIPTION("Mediatek Random Number Generator Driver");
+MODULE_AUTHOR("Sean Wang <sean.wang@mediatek.com>");
+MODULE_LICENSE("GPL");