diff options
Diffstat (limited to 'drivers/power/reset/syscon-poweroff.c')
-rw-r--r-- | drivers/power/reset/syscon-poweroff.c | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/drivers/power/reset/syscon-poweroff.c b/drivers/power/reset/syscon-poweroff.c new file mode 100644 index 000000000..ed58bdf41 --- /dev/null +++ b/drivers/power/reset/syscon-poweroff.c @@ -0,0 +1,102 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Generic Syscon Poweroff Driver + * + * Copyright (c) 2015, National Instruments Corp. + * Author: Moritz Fischer <moritz.fischer@ettus.com> + */ + +#include <linux/delay.h> +#include <linux/io.h> +#include <linux/notifier.h> +#include <linux/mfd/syscon.h> +#include <linux/of_address.h> +#include <linux/of_device.h> +#include <linux/platform_device.h> +#include <linux/pm.h> +#include <linux/regmap.h> + +static struct regmap *map; +static u32 offset; +static u32 value; +static u32 mask; + +static void syscon_poweroff(void) +{ + /* Issue the poweroff */ + regmap_update_bits(map, offset, mask, value); + + mdelay(1000); + + pr_emerg("Unable to poweroff system\n"); +} + +static int syscon_poweroff_probe(struct platform_device *pdev) +{ + int mask_err, value_err; + + map = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, "regmap"); + if (IS_ERR(map)) { + dev_err(&pdev->dev, "unable to get syscon"); + return PTR_ERR(map); + } + + if (of_property_read_u32(pdev->dev.of_node, "offset", &offset)) { + dev_err(&pdev->dev, "unable to read 'offset'"); + return -EINVAL; + } + + value_err = of_property_read_u32(pdev->dev.of_node, "value", &value); + mask_err = of_property_read_u32(pdev->dev.of_node, "mask", &mask); + if (value_err && mask_err) { + dev_err(&pdev->dev, "unable to read 'value' and 'mask'"); + return -EINVAL; + } + + if (value_err) { + /* support old binding */ + value = mask; + mask = 0xFFFFFFFF; + } else if (mask_err) { + /* support value without mask*/ + mask = 0xFFFFFFFF; + } + + if (pm_power_off) { + dev_err(&pdev->dev, "pm_power_off already claimed for %ps", + pm_power_off); + return -EBUSY; + } + + pm_power_off = syscon_poweroff; + + return 0; +} + +static int syscon_poweroff_remove(struct platform_device *pdev) +{ + if (pm_power_off == syscon_poweroff) + pm_power_off = NULL; + + return 0; +} + +static const struct of_device_id syscon_poweroff_of_match[] = { + { .compatible = "syscon-poweroff" }, + {} +}; + +static struct platform_driver syscon_poweroff_driver = { + .probe = syscon_poweroff_probe, + .remove = syscon_poweroff_remove, + .driver = { + .name = "syscon-poweroff", + .of_match_table = syscon_poweroff_of_match, + }, +}; + +static int __init syscon_poweroff_register(void) +{ + return platform_driver_register(&syscon_poweroff_driver); +} +device_initcall(syscon_poweroff_register); |