reset: Add support for the Amlogic Meson SoC Reset Controller
This patch adds the platform driver for the Amlogic Meson SoC Reset
Controller.
The Meson8b and GXBB SoCs are supported.
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
diff --git a/drivers/reset/reset-meson.c b/drivers/reset/reset-meson.c
new file mode 100644
index 0000000..c32f11a
--- /dev/null
+++ b/drivers/reset/reset-meson.c
@@ -0,0 +1,136 @@
+/*
+ * 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>
+ *
+ * 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>
+ *
+ * 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>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/reset-controller.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+#define REG_COUNT 8
+#define BITS_PER_REG 32
+
+struct meson_reset {
+ void __iomem *reg_base;
+ struct reset_controller_dev rcdev;
+};
+
+static int meson_reset_reset(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ struct meson_reset *data =
+ container_of(rcdev, struct meson_reset, rcdev);
+ unsigned int bank = id / BITS_PER_REG;
+ unsigned int offset = id % BITS_PER_REG;
+ void __iomem *reg_addr = data->reg_base + (bank << 2);
+
+ if (bank >= REG_COUNT)
+ return -EINVAL;
+
+ writel(BIT(offset), reg_addr);
+
+ return 0;
+}
+
+static const struct reset_control_ops meson_reset_ops = {
+ .reset = meson_reset_reset,
+};
+
+static const struct of_device_id meson_reset_dt_ids[] = {
+ { .compatible = "amlogic,meson8b-reset", },
+ { .compatible = "amlogic,meson-gxbb-reset", },
+ { /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, meson_reset_dt_ids);
+
+static int meson_reset_probe(struct platform_device *pdev)
+{
+ struct meson_reset *data;
+ struct resource *res;
+
+ data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ data->reg_base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(data->reg_base))
+ return PTR_ERR(data->reg_base);
+
+ platform_set_drvdata(pdev, data);
+
+ data->rcdev.owner = THIS_MODULE;
+ data->rcdev.nr_resets = REG_COUNT * BITS_PER_REG;
+ data->rcdev.ops = &meson_reset_ops;
+ data->rcdev.of_node = pdev->dev.of_node;
+
+ return devm_reset_controller_register(&pdev->dev, &data->rcdev);
+}
+
+static struct platform_driver meson_reset_driver = {
+ .probe = meson_reset_probe,
+ .driver = {
+ .name = "meson_reset",
+ .of_match_table = meson_reset_dt_ids,
+ },
+};
+
+module_platform_driver(meson_reset_driver);
+
+MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
+MODULE_DESCRIPTION("Amlogic Meson Reset Controller driver");
+MODULE_LICENSE("Dual BSD/GPL");
