1 files changed, 155 insertions, 0 deletions

diff --git a/drivers/reset/reset-zynq.c b/drivers/reset/reset-zynq.c
new file mode 100644
index 000000000000..89318a5d5bd7
--- /dev/null
+++ b/drivers/reset/reset-zynq.c
@@ -0,0 +1,155 @@
+/*
+ * Copyright (c) 2015, National Instruments Corp.
+ *
+ * Xilinx Zynq Reset controller driver
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * 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.
+ */
+
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/mfd/syscon.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/reset-controller.h>
+#include <linux/regmap.h>
+#include <linux/types.h>
+
+struct zynq_reset_data {
+        struct regmap *slcr;
+        struct reset_controller_dev rcdev;
+        u32 offset;
+};
+
+#define to_zynq_reset_data(p)           \
+        container_of((p), struct zynq_reset_data, rcdev)
+
+static int zynq_reset_assert(struct reset_controller_dev *rcdev,
+                             unsigned long id)
+{
+        struct zynq_reset_data *priv = to_zynq_reset_data(rcdev);
+
+        int bank = id / BITS_PER_LONG;
+        int offset = id % BITS_PER_LONG;
+
+        pr_debug("%s: %s reset bank %u offset %u\n", KBUILD_MODNAME, __func__,
+                 bank, offset);
+
+        return regmap_update_bits(priv->slcr,
+                                  priv->offset + (bank * 4),
+                                  BIT(offset),
+                                  BIT(offset));
+}
+
+static int zynq_reset_deassert(struct reset_controller_dev *rcdev,
+                               unsigned long id)
+{
+        struct zynq_reset_data *priv = to_zynq_reset_data(rcdev);
+
+        int bank = id / BITS_PER_LONG;
+        int offset = id % BITS_PER_LONG;
+
+        pr_debug("%s: %s reset bank %u offset %u\n", KBUILD_MODNAME, __func__,
+                 bank, offset);
+
+        return regmap_update_bits(priv->slcr,
+                                  priv->offset + (bank * 4),
+                                  BIT(offset),
+                                  ~BIT(offset));
+}
+
+static int zynq_reset_status(struct reset_controller_dev *rcdev,
+                             unsigned long id)
+{
+        struct zynq_reset_data *priv = to_zynq_reset_data(rcdev);
+
+        int bank = id / BITS_PER_LONG;
+        int offset = id % BITS_PER_LONG;
+        int ret;
+        u32 reg;
+
+        pr_debug("%s: %s reset bank %u offset %u\n", KBUILD_MODNAME, __func__,
+                 bank, offset);
+
+        ret = regmap_read(priv->slcr, priv->offset + (bank * 4), &reg);
+        if (ret)
+                return ret;
+
+        return !!(reg & BIT(offset));
+}
+
+static struct reset_control_ops zynq_reset_ops = {
+        .assert         = zynq_reset_assert,
+        .deassert       = zynq_reset_deassert,
+        .status         = zynq_reset_status,
+};
+
+static int zynq_reset_probe(struct platform_device *pdev)
+{
+        struct resource *res;
+        struct zynq_reset_data *priv;
+
+        priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+        if (!priv)
+                return -ENOMEM;
+        platform_set_drvdata(pdev, priv);
+
+        priv->slcr = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
+                                                     "syscon");
+        if (IS_ERR(priv->slcr)) {
+                dev_err(&pdev->dev, "unable to get zynq-slcr regmap");
+                return PTR_ERR(priv->slcr);
+        }
+
+        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        if (!res) {
+                dev_err(&pdev->dev, "missing IO resource\n");
+                return -ENODEV;
+        }
+
+        priv->offset = res->start;
+
+        priv->rcdev.owner = THIS_MODULE;
+        priv->rcdev.nr_resets = resource_size(res) / 4 * BITS_PER_LONG;
+        priv->rcdev.ops = &zynq_reset_ops;
+        priv->rcdev.of_node = pdev->dev.of_node;
+        reset_controller_register(&priv->rcdev);
+
+        return 0;
+}
+
+static int zynq_reset_remove(struct platform_device *pdev)
+{
+        struct zynq_reset_data *priv = platform_get_drvdata(pdev);
+
+        reset_controller_unregister(&priv->rcdev);
+
+        return 0;
+}
+
+static const struct of_device_id zynq_reset_dt_ids[] = {
+        { .compatible = "xlnx,zynq-reset", },
+        { /* sentinel */ },
+};
+
+static struct platform_driver zynq_reset_driver = {
+        .probe  = zynq_reset_probe,
+        .remove = zynq_reset_remove,
+        .driver = {
+                .name           = KBUILD_MODNAME,
+                .of_match_table = zynq_reset_dt_ids,
+        },
+};
+module_platform_driver(zynq_reset_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Moritz Fischer <moritz.fischer@ettus.com>");
+MODULE_DESCRIPTION("Zynq Reset Controller Driver");