85 lines
2.1 KiB
C
85 lines
2.1 KiB
C
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// SPDX-License-Identifier: GPL-2.0+
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/*
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* Cirrus EP93xx SoC reset driver
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*
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* Copyright (C) 2021 Nikita Shubin <nikita.shubin@maquefel.me>
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*/
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#include <linux/bits.h>
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#include <linux/container_of.h>
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#include <linux/delay.h>
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#include <linux/errno.h>
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#include <linux/mfd/syscon.h>
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#include <linux/module.h>
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#include <linux/mod_devicetable.h>
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#include <linux/notifier.h>
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#include <linux/reboot.h>
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#include <linux/slab.h>
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#include <linux/soc/cirrus/ep93xx.h>
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#define EP93XX_SYSCON_DEVCFG 0x80
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#define EP93XX_SYSCON_DEVCFG_SWRST BIT(31)
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struct ep93xx_restart {
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struct ep93xx_regmap_adev *aux_dev;
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struct notifier_block restart_handler;
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};
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static int ep93xx_restart_handle(struct notifier_block *this,
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unsigned long mode, void *cmd)
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{
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struct ep93xx_restart *priv =
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container_of(this, struct ep93xx_restart, restart_handler);
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struct ep93xx_regmap_adev *aux = priv->aux_dev;
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/* Issue the reboot */
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aux->update_bits(aux->map, aux->lock, EP93XX_SYSCON_DEVCFG,
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EP93XX_SYSCON_DEVCFG_SWRST, EP93XX_SYSCON_DEVCFG_SWRST);
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aux->update_bits(aux->map, aux->lock, EP93XX_SYSCON_DEVCFG,
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EP93XX_SYSCON_DEVCFG_SWRST, 0);
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return NOTIFY_DONE;
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}
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static int ep93xx_reboot_probe(struct auxiliary_device *adev,
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const struct auxiliary_device_id *id)
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{
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struct ep93xx_regmap_adev *rdev = to_ep93xx_regmap_adev(adev);
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struct device *dev = &adev->dev;
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struct ep93xx_restart *priv;
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int err;
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if (!rdev->update_bits)
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return -ENODEV;
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priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
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if (!priv)
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return -ENOMEM;
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priv->aux_dev = rdev;
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priv->restart_handler.notifier_call = ep93xx_restart_handle;
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priv->restart_handler.priority = 128;
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err = register_restart_handler(&priv->restart_handler);
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if (err)
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return dev_err_probe(dev, err, "can't register restart notifier\n");
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return 0;
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}
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static const struct auxiliary_device_id ep93xx_reboot_ids[] = {
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{
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.name = "soc_ep93xx.reset-ep93xx",
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},
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{ /* sentinel */ }
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};
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MODULE_DEVICE_TABLE(auxiliary, ep93xx_reboot_ids);
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static struct auxiliary_driver ep93xx_reboot_driver = {
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.probe = ep93xx_reboot_probe,
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.id_table = ep93xx_reboot_ids,
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};
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module_auxiliary_driver(ep93xx_reboot_driver);
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