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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /drivers/power/reset/vexpress-poweroff.c | |
parent | Initial commit. (diff) | |
download | linux-upstream/5.10.209.tar.xz linux-upstream/5.10.209.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/power/reset/vexpress-poweroff.c')
-rw-r--r-- | drivers/power/reset/vexpress-poweroff.c | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/drivers/power/reset/vexpress-poweroff.c b/drivers/power/reset/vexpress-poweroff.c new file mode 100644 index 000000000..1fdbcbd95 --- /dev/null +++ b/drivers/power/reset/vexpress-poweroff.c @@ -0,0 +1,149 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * + * Copyright (C) 2012 ARM Limited + */ + +#include <linux/delay.h> +#include <linux/notifier.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/platform_device.h> +#include <linux/reboot.h> +#include <linux/stat.h> +#include <linux/vexpress.h> + +static void vexpress_reset_do(struct device *dev, const char *what) +{ + int err = -ENOENT; + struct regmap *reg = dev_get_drvdata(dev); + + if (reg) { + err = regmap_write(reg, 0, 0); + if (!err) + mdelay(1000); + } + + dev_emerg(dev, "Unable to %s (%d)\n", what, err); +} + +static struct device *vexpress_power_off_device; +static atomic_t vexpress_restart_nb_refcnt = ATOMIC_INIT(0); + +static void vexpress_power_off(void) +{ + vexpress_reset_do(vexpress_power_off_device, "power off"); +} + +static struct device *vexpress_restart_device; + +static int vexpress_restart(struct notifier_block *this, unsigned long mode, + void *cmd) +{ + vexpress_reset_do(vexpress_restart_device, "restart"); + + return NOTIFY_DONE; +} + +static struct notifier_block vexpress_restart_nb = { + .notifier_call = vexpress_restart, + .priority = 128, +}; + +static ssize_t vexpress_reset_active_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + return sprintf(buf, "%d\n", vexpress_restart_device == dev); +} + +static ssize_t vexpress_reset_active_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t count) +{ + long value; + int err = kstrtol(buf, 0, &value); + + if (!err && value) + vexpress_restart_device = dev; + + return err ? err : count; +} + +static DEVICE_ATTR(active, S_IRUGO | S_IWUSR, vexpress_reset_active_show, + vexpress_reset_active_store); + + +enum vexpress_reset_func { FUNC_RESET, FUNC_SHUTDOWN, FUNC_REBOOT }; + +static const struct of_device_id vexpress_reset_of_match[] = { + { + .compatible = "arm,vexpress-reset", + .data = (void *)FUNC_RESET, + }, { + .compatible = "arm,vexpress-shutdown", + .data = (void *)FUNC_SHUTDOWN + }, { + .compatible = "arm,vexpress-reboot", + .data = (void *)FUNC_REBOOT + }, + {} +}; + +static int _vexpress_register_restart_handler(struct device *dev) +{ + int err; + + vexpress_restart_device = dev; + if (atomic_inc_return(&vexpress_restart_nb_refcnt) == 1) { + err = register_restart_handler(&vexpress_restart_nb); + if (err) { + dev_err(dev, "cannot register restart handler (err=%d)\n", err); + atomic_dec(&vexpress_restart_nb_refcnt); + return err; + } + } + device_create_file(dev, &dev_attr_active); + + return 0; +} + +static int vexpress_reset_probe(struct platform_device *pdev) +{ + const struct of_device_id *match = + of_match_device(vexpress_reset_of_match, &pdev->dev); + struct regmap *regmap; + int ret = 0; + + if (!match) + return -EINVAL; + + regmap = devm_regmap_init_vexpress_config(&pdev->dev); + if (IS_ERR(regmap)) + return PTR_ERR(regmap); + dev_set_drvdata(&pdev->dev, regmap); + + switch ((enum vexpress_reset_func)match->data) { + case FUNC_SHUTDOWN: + vexpress_power_off_device = &pdev->dev; + pm_power_off = vexpress_power_off; + break; + case FUNC_RESET: + if (!vexpress_restart_device) + ret = _vexpress_register_restart_handler(&pdev->dev); + break; + case FUNC_REBOOT: + ret = _vexpress_register_restart_handler(&pdev->dev); + break; + }; + + return ret; +} + +static struct platform_driver vexpress_reset_driver = { + .probe = vexpress_reset_probe, + .driver = { + .name = "vexpress-reset", + .of_match_table = vexpress_reset_of_match, + .suppress_bind_attrs = true, + }, +}; +builtin_platform_driver(vexpress_reset_driver); |