1 files changed, 79 insertions, 77 deletions

diff --git a/drivers/char/hw_random/meson-rng.c b/drivers/char/hw_random/meson-rng.c
index 2e23be802a62..75225eb9fef6 100644
--- a/drivers/char/hw_random/meson-rng.c
+++ b/drivers/char/hw_random/meson-rng.c
@@ -1,58 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
 /*
- * This file is provided under a dual BSD/GPLv2 license.  When using or
- * redistributing this file, you may do so under either license.
- *
- * GPL LICENSE SUMMARY
- *
  * Copyright (c) 2016 BayLibre, SAS.
  * Author: Neil Armstrong <narmstrong@baylibre.com>
  * Copyright (C) 2014 Amlogic, Inc.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of version 2 of the GNU General Public License as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that 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/>.
- * The full GNU General Public License is included in this distribution
- * in the file called COPYING.
- *
- * BSD LICENSE
- *
- * Copyright (c) 2016 BayLibre, SAS.
- * Author: Neil Armstrong <narmstrong@baylibre.com>
- * Copyright (C) 2014 Amlogic, Inc.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- *
- *   * Redistributions of source code must retain the above copyright
- *     notice, this list of conditions and the following disclaimer.
- *   * Redistributions in binary form must reproduce the above copyright
- *     notice, this list of conditions and the following disclaimer in
- *     the documentation and/or other materials provided with the
- *     distribution.
- *   * Neither the name of Intel Corporation nor the names of its
- *     contributors may be used to endorse or promote products derived
- *     from this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 #include <linux/err.h>
 #include <linux/module.h>
@@ -63,14 +13,23 @@
 #include <linux/types.h>
 #include <linux/of.h>
 #include <linux/clk.h>
+#include <linux/iopoll.h>
 
-#define RNG_DATA 0x00
+#define RNG_DATA	0x00
+#define RNG_S4_DATA	0x08
+#define RNG_S4_CFG	0x00
+
+#define RUN_BIT		BIT(0)
+#define SEED_READY_STS_BIT	BIT(31)
+
+struct meson_rng_priv {
+	int (*read)(struct hwrng *rng, void *buf, size_t max, bool wait);
+};
 
 struct meson_rng_data {
 	void __iomem *base;
-	struct platform_device *pdev;
 	struct hwrng rng;
-	struct clk *core_clk;
+	struct device *dev;
 };
 
 static int meson_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait)
@@ -83,53 +42,96 @@ static int meson_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait)
 	return sizeof(u32);
 }
 
-static void meson_rng_clk_disable(void *data)
+static int meson_rng_wait_status(void __iomem *cfg_addr, int bit)
 {
-	clk_disable_unprepare(data);
+	u32 status = 0;
+	int ret;
+
+	ret = readl_relaxed_poll_timeout_atomic(cfg_addr,
+						status, !(status & bit),
+						10, 10000);
+	if (ret)
+		return -EBUSY;
+
+	return 0;
+}
+
+static int meson_s4_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait)
+{
+	struct meson_rng_data *data =
+			container_of(rng, struct meson_rng_data, rng);
+
+	void __iomem *cfg_addr = data->base + RNG_S4_CFG;
+	int err;
+
+	writel_relaxed(readl_relaxed(cfg_addr) | SEED_READY_STS_BIT, cfg_addr);
+
+	err = meson_rng_wait_status(cfg_addr, SEED_READY_STS_BIT);
+	if (err) {
+		dev_err(data->dev, "Seed isn't ready, try again\n");
+		return err;
+	}
+
+	err = meson_rng_wait_status(cfg_addr, RUN_BIT);
+	if (err) {
+		dev_err(data->dev, "Can't get random number, try again\n");
+		return err;
+	}
+
+	*(u32 *)buf = readl_relaxed(data->base + RNG_S4_DATA);
+
+	return sizeof(u32);
 }
 
 static int meson_rng_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct meson_rng_data *data;
-	struct resource *res;
-	int ret;
+	struct clk *core_clk;
+	const struct meson_rng_priv *priv;
 
 	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
 	if (!data)
 		return -ENOMEM;
 
-	data->pdev = pdev;
+	priv = device_get_match_data(&pdev->dev);
+	if (!priv)
+		return -ENODEV;
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	data->base = devm_ioremap_resource(dev, res);
+	data->base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(data->base))
 		return PTR_ERR(data->base);
 
-	data->core_clk = devm_clk_get(dev, "core");
-	if (IS_ERR(data->core_clk))
-		data->core_clk = NULL;
-
-	if (data->core_clk) {
-		ret = clk_prepare_enable(data->core_clk);
-		if (ret)
-			return ret;
-		ret = devm_add_action_or_reset(dev, meson_rng_clk_disable,
-					       data->core_clk);
-		if (ret)
-			return ret;
-	}
+	core_clk = devm_clk_get_optional_enabled(dev, "core");
+	if (IS_ERR(core_clk))
+		return dev_err_probe(dev, PTR_ERR(core_clk),
+				     "Failed to get core clock\n");
 
 	data->rng.name = pdev->name;
-	data->rng.read = meson_rng_read;
+	data->rng.read = priv->read;
 
-	platform_set_drvdata(pdev, data);
+	data->dev = &pdev->dev;
 
 	return devm_hwrng_register(dev, &data->rng);
 }
 
+static const struct meson_rng_priv meson_rng_priv = {
+	.read = meson_rng_read,
+};
+
+static const struct meson_rng_priv meson_rng_priv_s4 = {
+	.read = meson_s4_rng_read,
+};
+
 static const struct of_device_id meson_rng_of_match[] = {
-	{ .compatible = "amlogic,meson-rng", },
+	{
+		.compatible = "amlogic,meson-rng",
+		.data = (void *)&meson_rng_priv,
+	},
+	{
+		.compatible = "amlogic,meson-s4-rng",
+		.data = (void *)&meson_rng_priv_s4,
+	},
 	{},
 };
 MODULE_DEVICE_TABLE(of, meson_rng_of_match);