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102 lines
2.2 KiB
102 lines
2.2 KiB
// 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 <[email protected]> |
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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_address.h> |
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#include <linux/of_device.h> |
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#include <linux/platform_device.h> |
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#include <linux/pm.h> |
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#include <linux/regmap.h> |
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static struct regmap *map; |
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static u32 offset; |
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static u32 value; |
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static u32 mask; |
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static void syscon_poweroff(void) |
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{ |
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/* Issue the poweroff */ |
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regmap_update_bits(map, offset, mask, value); |
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mdelay(1000); |
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pr_emerg("Unable to poweroff system\n"); |
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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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int mask_err, value_err; |
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map = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, "regmap"); |
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if (IS_ERR(map)) { |
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dev_err(&pdev->dev, "unable to get syscon"); |
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return PTR_ERR(map); |
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} |
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if (of_property_read_u32(pdev->dev.of_node, "offset", &offset)) { |
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dev_err(&pdev->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(pdev->dev.of_node, "value", &value); |
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mask_err = of_property_read_u32(pdev->dev.of_node, "mask", &mask); |
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if (value_err && mask_err) { |
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dev_err(&pdev->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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value = mask; |
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mask = 0xFFFFFFFF; |
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} else if (mask_err) { |
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/* support value without mask*/ |
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mask = 0xFFFFFFFF; |
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} |
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if (pm_power_off) { |
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dev_err(&pdev->dev, "pm_power_off already claimed for %ps", |
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pm_power_off); |
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return -EBUSY; |
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} |
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pm_power_off = syscon_poweroff; |
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return 0; |
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} |
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static int syscon_poweroff_remove(struct platform_device *pdev) |
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{ |
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if (pm_power_off == syscon_poweroff) |
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pm_power_off = NULL; |
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return 0; |
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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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.remove = syscon_poweroff_remove, |
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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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static int __init syscon_poweroff_register(void) |
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{ |
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return platform_driver_register(&syscon_poweroff_driver); |
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} |
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device_initcall(syscon_poweroff_register);
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