reset: Add Oxford Semiconductor Reset Controller driver
Add System reset controller driver for Oxford Semiconductor OXNAS SoC
Family.
CC: Ma Haijun <mahaijuns@gmail.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
diff --git a/drivers/reset/reset-oxnas.c b/drivers/reset/reset-oxnas.c
new file mode 100644
index 0000000..c60fb2d
--- /dev/null
+++ b/drivers/reset/reset-oxnas.c
@@ -0,0 +1,136 @@
+/*
+ * drivers/reset/reset-oxnas.c
+ *
+ * Copyright (C) 2016 Neil Armstrong <narmstrong@baylibre.com>
+ * Copyright (C) 2014 Ma Haijun <mahaijuns@gmail.com>
+ * Copyright (C) 2009 Oxford Semiconductor Ltd
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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/>.
+ */
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/reset-controller.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/types.h>
+#include <linux/regmap.h>
+#include <linux/mfd/syscon.h>
+
+/* Regmap offsets */
+#define RST_SET_REGOFFSET 0x34
+#define RST_CLR_REGOFFSET 0x38
+
+struct oxnas_reset {
+ struct regmap *regmap;
+ struct reset_controller_dev rcdev;
+};
+
+static int oxnas_reset_reset(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ struct oxnas_reset *data =
+ container_of(rcdev, struct oxnas_reset, rcdev);
+
+ regmap_write(data->regmap, RST_SET_REGOFFSET, BIT(id));
+ msleep(50);
+ regmap_write(data->regmap, RST_CLR_REGOFFSET, BIT(id));
+
+ return 0;
+}
+
+static int oxnas_reset_assert(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ struct oxnas_reset *data =
+ container_of(rcdev, struct oxnas_reset, rcdev);
+
+ regmap_write(data->regmap, RST_SET_REGOFFSET, BIT(id));
+
+ return 0;
+}
+
+static int oxnas_reset_deassert(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ struct oxnas_reset *data =
+ container_of(rcdev, struct oxnas_reset, rcdev);
+
+ regmap_write(data->regmap, RST_CLR_REGOFFSET, BIT(id));
+
+ return 0;
+}
+
+static const struct reset_control_ops oxnas_reset_ops = {
+ .reset = oxnas_reset_reset,
+ .assert = oxnas_reset_assert,
+ .deassert = oxnas_reset_deassert,
+};
+
+static const struct of_device_id oxnas_reset_dt_ids[] = {
+ { .compatible = "oxsemi,ox810se-reset", },
+ { /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, oxnas_reset_dt_ids);
+
+static int oxnas_reset_probe(struct platform_device *pdev)
+{
+ struct oxnas_reset *data;
+ struct device *parent;
+
+ parent = pdev->dev.parent;
+ if (!parent) {
+ dev_err(&pdev->dev, "no parent\n");
+ return -ENODEV;
+ }
+
+ data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ data->regmap = syscon_node_to_regmap(parent->of_node);
+ if (IS_ERR(data->regmap)) {
+ dev_err(&pdev->dev, "failed to get parent regmap\n");
+ return PTR_ERR(data->regmap);
+ }
+
+ platform_set_drvdata(pdev, data);
+
+ data->rcdev.owner = THIS_MODULE;
+ data->rcdev.nr_resets = 32;
+ data->rcdev.ops = &oxnas_reset_ops;
+ data->rcdev.of_node = pdev->dev.of_node;
+
+ return reset_controller_register(&data->rcdev);
+}
+
+static int oxnas_reset_remove(struct platform_device *pdev)
+{
+ struct oxnas_reset *data = platform_get_drvdata(pdev);
+
+ reset_controller_unregister(&data->rcdev);
+
+ return 0;
+}
+
+static struct platform_driver oxnas_reset_driver = {
+ .probe = oxnas_reset_probe,
+ .remove = oxnas_reset_remove,
+ .driver = {
+ .name = "oxnas-reset",
+ .of_match_table = oxnas_reset_dt_ids,
+ },
+};
+
+module_platform_driver(oxnas_reset_driver);