mirror of https://gitee.com/openkylin/linux.git
105 lines
2.5 KiB
C
105 lines
2.5 KiB
C
/*
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* Copyright (C) 2014 Marvell Technology Group Ltd.
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*
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* Marvell Berlin reset driver
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*
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* Antoine Tenart <antoine.tenart@free-electrons.com>
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* Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
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*
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* This file is licensed under the terms of the GNU General Public
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* License version 2. This program is licensed "as is" without any
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* warranty of any kind, whether express or implied.
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*/
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#include <linux/delay.h>
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#include <linux/io.h>
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#include <linux/mfd/syscon.h>
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#include <linux/init.h>
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#include <linux/of.h>
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#include <linux/of_address.h>
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#include <linux/platform_device.h>
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#include <linux/regmap.h>
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#include <linux/reset-controller.h>
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#include <linux/slab.h>
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#include <linux/types.h>
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#define BERLIN_MAX_RESETS 32
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#define to_berlin_reset_priv(p) \
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container_of((p), struct berlin_reset_priv, rcdev)
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struct berlin_reset_priv {
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struct regmap *regmap;
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struct reset_controller_dev rcdev;
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};
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static int berlin_reset_reset(struct reset_controller_dev *rcdev,
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unsigned long id)
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{
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struct berlin_reset_priv *priv = to_berlin_reset_priv(rcdev);
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int offset = id >> 8;
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int mask = BIT(id & 0x1f);
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regmap_write(priv->regmap, offset, mask);
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/* let the reset be effective */
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udelay(10);
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return 0;
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}
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static const struct reset_control_ops berlin_reset_ops = {
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.reset = berlin_reset_reset,
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};
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static int berlin_reset_xlate(struct reset_controller_dev *rcdev,
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const struct of_phandle_args *reset_spec)
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{
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unsigned offset, bit;
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offset = reset_spec->args[0];
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bit = reset_spec->args[1];
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if (bit >= BERLIN_MAX_RESETS)
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return -EINVAL;
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return (offset << 8) | bit;
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}
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static int berlin2_reset_probe(struct platform_device *pdev)
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{
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struct device_node *parent_np = of_get_parent(pdev->dev.of_node);
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struct berlin_reset_priv *priv;
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priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
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if (!priv)
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return -ENOMEM;
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priv->regmap = syscon_node_to_regmap(parent_np);
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of_node_put(parent_np);
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if (IS_ERR(priv->regmap))
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return PTR_ERR(priv->regmap);
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priv->rcdev.owner = THIS_MODULE;
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priv->rcdev.ops = &berlin_reset_ops;
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priv->rcdev.of_node = pdev->dev.of_node;
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priv->rcdev.of_reset_n_cells = 2;
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priv->rcdev.of_xlate = berlin_reset_xlate;
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return reset_controller_register(&priv->rcdev);
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}
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static const struct of_device_id berlin_reset_dt_match[] = {
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{ .compatible = "marvell,berlin2-reset" },
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{ },
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};
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static struct platform_driver berlin_reset_driver = {
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.probe = berlin2_reset_probe,
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.driver = {
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.name = "berlin2-reset",
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.of_match_table = berlin_reset_dt_match,
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},
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};
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builtin_platform_driver(berlin_reset_driver);
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