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/*
* 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), ®);
if (ret)
return ret;
return !!(reg & BIT(offset));
}
static const 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;
return devm_reset_controller_register(&pdev->dev, &priv->rcdev);
}
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,
.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");
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