diff options
Diffstat (limited to 'drivers/power/reset/syscon-reboot.c')
| -rw-r--r-- | drivers/power/reset/syscon-reboot.c | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/drivers/power/reset/syscon-reboot.c b/drivers/power/reset/syscon-reboot.c new file mode 100644 index 000000000000..2e2cf5f62d73 --- /dev/null +++ b/drivers/power/reset/syscon-reboot.c @@ -0,0 +1,160 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Generic Syscon Reboot Driver + * + * Copyright (c) 2013, Applied Micro Circuits Corporation + * Author: Feng Kan <fkan@apm.com> + */ +#include <linux/delay.h> +#include <linux/io.h> +#include <linux/notifier.h> +#include <linux/mfd/syscon.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/reboot.h> +#include <linux/regmap.h> + +struct reboot_mode_bits { + u32 offset; + u32 mask; + u32 value; + bool valid; +}; + +struct reboot_data { + struct reboot_mode_bits mode_bits[REBOOT_SOFT + 1]; + struct reboot_mode_bits catchall; +}; + +struct syscon_reboot_context { + struct regmap *map; + + const struct reboot_data *rd; /* from of match data, if any */ + struct reboot_mode_bits catchall; /* from DT */ + + 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); + const struct reboot_mode_bits *mode_bits; + + if (ctx->rd) { + if (mode < ARRAY_SIZE(ctx->rd->mode_bits) && + ctx->rd->mode_bits[mode].valid) + mode_bits = &ctx->rd->mode_bits[mode]; + else + mode_bits = &ctx->rd->catchall; + } else { + mode_bits = &ctx->catchall; + } + + /* Issue the reboot */ + regmap_update_bits(ctx->map, mode_bits->offset, mode_bits->mask, + mode_bits->value); + + 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 priority; + 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)) { + ctx->map = syscon_node_to_regmap(dev->parent->of_node); + if (IS_ERR(ctx->map)) + return PTR_ERR(ctx->map); + } + + if (of_property_read_s32(pdev->dev.of_node, "priority", &priority)) + priority = 192; + + ctx->rd = of_device_get_match_data(dev); + if (!ctx->rd) { + int mask_err, value_err; + + if (of_property_read_u32(pdev->dev.of_node, "offset", + &ctx->catchall.offset) && + of_property_read_u32(pdev->dev.of_node, "reg", + &ctx->catchall.offset)) + return -EINVAL; + + value_err = of_property_read_u32(pdev->dev.of_node, "value", + &ctx->catchall.value); + mask_err = of_property_read_u32(pdev->dev.of_node, "mask", + &ctx->catchall.mask); + if (value_err && mask_err) { + dev_err(dev, "unable to read 'value' and 'mask'"); + return -EINVAL; + } + + if (value_err) { + /* support old binding */ + ctx->catchall.value = ctx->catchall.mask; + ctx->catchall.mask = 0xFFFFFFFF; + } else if (mask_err) { + /* support value without mask */ + ctx->catchall.mask = 0xFFFFFFFF; + } + } + + ctx->restart_handler.notifier_call = syscon_restart_handle; + ctx->restart_handler.priority = priority; + 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 reboot_data gs101_reboot_data = { + .mode_bits = { + [REBOOT_WARM] = { + .offset = 0x3a00, /* SYSTEM_CONFIGURATION */ + .mask = 0x00000002, /* SWRESET_SYSTEM */ + .value = 0x00000002, + .valid = true, + }, + [REBOOT_SOFT] = { + .offset = 0x3a00, /* SYSTEM_CONFIGURATION */ + .mask = 0x00000002, /* SWRESET_SYSTEM */ + .value = 0x00000002, + .valid = true, + }, + }, + .catchall = { + .offset = 0x3e9c, /* PAD_CTRL_PWR_HOLD */ + .mask = 0x00000100, + .value = 0x00000000, + }, +}; + +static const struct of_device_id syscon_reboot_of_match[] = { + { .compatible = "google,gs101-reboot", .data = &gs101_reboot_data }, + { .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); |