99 lines
2.3 KiB
C
99 lines
2.3 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Generic Syscon Poweroff Driver
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*
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* Copyright (c) 2015, National Instruments Corp.
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* Author: Moritz Fischer <moritz.fischer@ettus.com>
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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/notifier.h>
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#include <linux/mfd/syscon.h>
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#include <linux/of.h>
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#include <linux/platform_device.h>
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#include <linux/pm.h>
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#include <linux/reboot.h>
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#include <linux/regmap.h>
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struct syscon_poweroff_data {
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struct regmap *map;
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u32 offset;
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u32 value;
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u32 mask;
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};
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static int syscon_poweroff(struct sys_off_data *off_data)
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{
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struct syscon_poweroff_data *data = off_data->cb_data;
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/* Issue the poweroff */
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regmap_update_bits(data->map, data->offset, data->mask, data->value);
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mdelay(1000);
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pr_emerg("Unable to poweroff system\n");
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return NOTIFY_DONE;
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}
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static int syscon_poweroff_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct syscon_poweroff_data *data;
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int mask_err, value_err;
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data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
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if (!data)
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return -ENOMEM;
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data->map = syscon_regmap_lookup_by_phandle(dev->of_node, "regmap");
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if (IS_ERR(data->map)) {
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data->map = syscon_node_to_regmap(dev->parent->of_node);
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if (IS_ERR(data->map)) {
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dev_err(dev, "unable to get syscon");
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return PTR_ERR(data->map);
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}
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}
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if (of_property_read_u32(dev->of_node, "offset", &data->offset)) {
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dev_err(dev, "unable to read 'offset'");
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return -EINVAL;
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}
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value_err = of_property_read_u32(dev->of_node, "value", &data->value);
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mask_err = of_property_read_u32(dev->of_node, "mask", &data->mask);
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if (value_err && mask_err) {
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dev_err(dev, "unable to read 'value' and 'mask'");
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return -EINVAL;
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}
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if (value_err) {
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/* support old binding */
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data->value = data->mask;
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data->mask = 0xFFFFFFFF;
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} else if (mask_err) {
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/* support value without mask*/
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data->mask = 0xFFFFFFFF;
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}
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return devm_register_sys_off_handler(&pdev->dev,
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SYS_OFF_MODE_POWER_OFF,
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SYS_OFF_PRIO_DEFAULT,
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syscon_poweroff, data);
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}
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static const struct of_device_id syscon_poweroff_of_match[] = {
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{ .compatible = "syscon-poweroff" },
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{}
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};
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static struct platform_driver syscon_poweroff_driver = {
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.probe = syscon_poweroff_probe,
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.driver = {
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.name = "syscon-poweroff",
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.of_match_table = syscon_poweroff_of_match,
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},
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};
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builtin_platform_driver(syscon_poweroff_driver);
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