diff options
Diffstat (limited to 'drivers/power/reset/syscon-reboot.c')
-rw-r--r-- | drivers/power/reset/syscon-reboot.c | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/drivers/power/reset/syscon-reboot.c b/drivers/power/reset/syscon-reboot.c new file mode 100644 index 000000000..7d0d269a0 --- /dev/null +++ b/drivers/power/reset/syscon-reboot.c @@ -0,0 +1,91 @@ +/* + * Generic Syscon Reboot Driver + * + * Copyright (c) 2013, Applied Micro Circuits Corporation + * Author: Feng Kan <fkan@apm.com> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ +#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/reboot.h> +#include <linux/regmap.h> + +struct syscon_reboot_context { + struct regmap *map; + u32 offset; + u32 mask; + struct notifier_block restart_handler; +}; + +static int syscon_restart_handle(struct notifier_block *this, + unsigned long mode, void *cmd) +{ + struct syscon_reboot_context *ctx = + container_of(this, struct syscon_reboot_context, + restart_handler); + + /* Issue the reboot */ + regmap_write(ctx->map, ctx->offset, ctx->mask); + + mdelay(1000); + + pr_emerg("Unable to restart system\n"); + return NOTIFY_DONE; +} + +static int syscon_reboot_probe(struct platform_device *pdev) +{ + struct syscon_reboot_context *ctx; + struct device *dev = &pdev->dev; + int err; + + ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL); + if (!ctx) + return -ENOMEM; + + ctx->map = syscon_regmap_lookup_by_phandle(dev->of_node, "regmap"); + if (IS_ERR(ctx->map)) + return PTR_ERR(ctx->map); + + if (of_property_read_u32(pdev->dev.of_node, "offset", &ctx->offset)) + return -EINVAL; + + if (of_property_read_u32(pdev->dev.of_node, "mask", &ctx->mask)) + return -EINVAL; + + ctx->restart_handler.notifier_call = syscon_restart_handle; + ctx->restart_handler.priority = 192; + err = register_restart_handler(&ctx->restart_handler); + if (err) + dev_err(dev, "can't register restart notifier (err=%d)\n", err); + + return err; +} + +static const struct of_device_id syscon_reboot_of_match[] = { + { .compatible = "syscon-reboot" }, + {} +}; + +static struct platform_driver syscon_reboot_driver = { + .probe = syscon_reboot_probe, + .driver = { + .name = "syscon-reboot", + .of_match_table = syscon_reboot_of_match, + }, +}; +builtin_platform_driver(syscon_reboot_driver); |