2 * Copyright (c) 2015, National Instruments Corp.
4 * Xilinx Zynq Reset controller driver
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; version 2 of the License.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
16 #include <linux/err.h>
18 #include <linux/module.h>
19 #include <linux/mfd/syscon.h>
21 #include <linux/platform_device.h>
22 #include <linux/reset-controller.h>
23 #include <linux/regmap.h>
24 #include <linux/types.h>
26 struct zynq_reset_data {
28 struct reset_controller_dev rcdev;
32 #define to_zynq_reset_data(p) \
33 container_of((p), struct zynq_reset_data, rcdev)
35 static int zynq_reset_assert(struct reset_controller_dev *rcdev,
38 struct zynq_reset_data *priv = to_zynq_reset_data(rcdev);
40 int bank = id / BITS_PER_LONG;
41 int offset = id % BITS_PER_LONG;
43 pr_debug("%s: %s reset bank %u offset %u\n", KBUILD_MODNAME, __func__,
46 return regmap_update_bits(priv->slcr,
47 priv->offset + (bank * 4),
52 static int zynq_reset_deassert(struct reset_controller_dev *rcdev,
55 struct zynq_reset_data *priv = to_zynq_reset_data(rcdev);
57 int bank = id / BITS_PER_LONG;
58 int offset = id % BITS_PER_LONG;
60 pr_debug("%s: %s reset bank %u offset %u\n", KBUILD_MODNAME, __func__,
63 return regmap_update_bits(priv->slcr,
64 priv->offset + (bank * 4),
69 static int zynq_reset_status(struct reset_controller_dev *rcdev,
72 struct zynq_reset_data *priv = to_zynq_reset_data(rcdev);
74 int bank = id / BITS_PER_LONG;
75 int offset = id % BITS_PER_LONG;
79 pr_debug("%s: %s reset bank %u offset %u\n", KBUILD_MODNAME, __func__,
82 ret = regmap_read(priv->slcr, priv->offset + (bank * 4), ®);
86 return !!(reg & BIT(offset));
89 static struct reset_control_ops zynq_reset_ops = {
90 .assert = zynq_reset_assert,
91 .deassert = zynq_reset_deassert,
92 .status = zynq_reset_status,
95 static int zynq_reset_probe(struct platform_device *pdev)
98 struct zynq_reset_data *priv;
100 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
103 platform_set_drvdata(pdev, priv);
105 priv->slcr = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
107 if (IS_ERR(priv->slcr)) {
108 dev_err(&pdev->dev, "unable to get zynq-slcr regmap");
109 return PTR_ERR(priv->slcr);
112 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
114 dev_err(&pdev->dev, "missing IO resource\n");
118 priv->offset = res->start;
120 priv->rcdev.owner = THIS_MODULE;
121 priv->rcdev.nr_resets = resource_size(res) / 4 * BITS_PER_LONG;
122 priv->rcdev.ops = &zynq_reset_ops;
123 priv->rcdev.of_node = pdev->dev.of_node;
124 reset_controller_register(&priv->rcdev);
129 static int zynq_reset_remove(struct platform_device *pdev)
131 struct zynq_reset_data *priv = platform_get_drvdata(pdev);
133 reset_controller_unregister(&priv->rcdev);
138 static const struct of_device_id zynq_reset_dt_ids[] = {
139 { .compatible = "xlnx,zynq-reset", },
143 static struct platform_driver zynq_reset_driver = {
144 .probe = zynq_reset_probe,
145 .remove = zynq_reset_remove,
147 .name = KBUILD_MODNAME,
148 .of_match_table = zynq_reset_dt_ids,
151 module_platform_driver(zynq_reset_driver);
153 MODULE_LICENSE("GPL v2");
154 MODULE_AUTHOR("Moritz Fischer <moritz.fischer@ettus.com>");
155 MODULE_DESCRIPTION("Zynq Reset Controller Driver");