150 lines
3.4 KiB
C
150 lines
3.4 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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*
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* Copyright (C) 2012 ARM Limited
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*/
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#include <linux/delay.h>
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#include <linux/notifier.h>
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#include <linux/of.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/reboot.h>
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#include <linux/stat.h>
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#include <linux/vexpress.h>
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static void vexpress_reset_do(struct device *dev, const char *what)
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{
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int err = -ENOENT;
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struct regmap *reg = dev_get_drvdata(dev);
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if (reg) {
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err = regmap_write(reg, 0, 0);
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if (!err)
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mdelay(1000);
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}
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dev_emerg(dev, "Unable to %s (%d)\n", what, err);
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}
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static struct device *vexpress_power_off_device;
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static atomic_t vexpress_restart_nb_refcnt = ATOMIC_INIT(0);
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static void vexpress_power_off(void)
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{
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vexpress_reset_do(vexpress_power_off_device, "power off");
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}
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static struct device *vexpress_restart_device;
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static int vexpress_restart(struct notifier_block *this, unsigned long mode,
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void *cmd)
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{
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vexpress_reset_do(vexpress_restart_device, "restart");
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return NOTIFY_DONE;
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}
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static struct notifier_block vexpress_restart_nb = {
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.notifier_call = vexpress_restart,
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.priority = 128,
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};
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static ssize_t vexpress_reset_active_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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return sprintf(buf, "%d\n", vexpress_restart_device == dev);
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}
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static ssize_t vexpress_reset_active_store(struct device *dev,
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struct device_attribute *attr, const char *buf, size_t count)
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{
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long value;
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int err = kstrtol(buf, 0, &value);
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if (!err && value)
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vexpress_restart_device = dev;
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return err ? err : count;
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}
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static DEVICE_ATTR(active, S_IRUGO | S_IWUSR, vexpress_reset_active_show,
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vexpress_reset_active_store);
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enum vexpress_reset_func { FUNC_RESET, FUNC_SHUTDOWN, FUNC_REBOOT };
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static const struct of_device_id vexpress_reset_of_match[] = {
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{
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.compatible = "arm,vexpress-reset",
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.data = (void *)FUNC_RESET,
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}, {
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.compatible = "arm,vexpress-shutdown",
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.data = (void *)FUNC_SHUTDOWN
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}, {
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.compatible = "arm,vexpress-reboot",
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.data = (void *)FUNC_REBOOT
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},
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{}
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};
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static int _vexpress_register_restart_handler(struct device *dev)
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{
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int err;
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vexpress_restart_device = dev;
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if (atomic_inc_return(&vexpress_restart_nb_refcnt) == 1) {
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err = register_restart_handler(&vexpress_restart_nb);
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if (err) {
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dev_err(dev, "cannot register restart handler (err=%d)\n", err);
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atomic_dec(&vexpress_restart_nb_refcnt);
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return err;
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}
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}
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device_create_file(dev, &dev_attr_active);
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return 0;
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}
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static int vexpress_reset_probe(struct platform_device *pdev)
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{
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const struct of_device_id *match =
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of_match_device(vexpress_reset_of_match, &pdev->dev);
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struct regmap *regmap;
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int ret = 0;
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if (!match)
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return -EINVAL;
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regmap = devm_regmap_init_vexpress_config(&pdev->dev);
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if (IS_ERR(regmap))
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return PTR_ERR(regmap);
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dev_set_drvdata(&pdev->dev, regmap);
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switch ((enum vexpress_reset_func)match->data) {
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case FUNC_SHUTDOWN:
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vexpress_power_off_device = &pdev->dev;
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pm_power_off = vexpress_power_off;
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break;
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case FUNC_RESET:
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if (!vexpress_restart_device)
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ret = _vexpress_register_restart_handler(&pdev->dev);
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break;
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case FUNC_REBOOT:
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ret = _vexpress_register_restart_handler(&pdev->dev);
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break;
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}
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return ret;
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}
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static struct platform_driver vexpress_reset_driver = {
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.probe = vexpress_reset_probe,
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.driver = {
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.name = "vexpress-reset",
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.of_match_table = vexpress_reset_of_match,
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.suppress_bind_attrs = true,
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},
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};
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builtin_platform_driver(vexpress_reset_driver);
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