diff options
Diffstat (limited to 'drivers/power/reset/st-poweroff.c')
-rw-r--r-- | drivers/power/reset/st-poweroff.c | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/drivers/power/reset/st-poweroff.c b/drivers/power/reset/st-poweroff.c new file mode 100644 index 000000000..2046b3123 --- /dev/null +++ b/drivers/power/reset/st-poweroff.c @@ -0,0 +1,115 @@ +/* + * Copyright (C) 2014 STMicroelectronics + * + * Power off Restart driver, used in STMicroelectronics devices. + * + * Author: Christophe Kerello <christophe.kerello@st.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2, as + * published by the Free Software Foundation. + */ + +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_platform.h> +#include <linux/platform_device.h> +#include <linux/mfd/syscon.h> +#include <linux/reboot.h> +#include <linux/regmap.h> + +struct reset_syscfg { + struct regmap *regmap; + /* syscfg used for reset */ + unsigned int offset_rst; + unsigned int mask_rst; + /* syscfg used for unmask the reset */ + unsigned int offset_rst_msk; + unsigned int mask_rst_msk; +}; + +/* STiH407 */ +#define STIH407_SYSCFG_4000 0x0 +#define STIH407_SYSCFG_4008 0x20 + +static struct reset_syscfg stih407_reset = { + .offset_rst = STIH407_SYSCFG_4000, + .mask_rst = BIT(0), + .offset_rst_msk = STIH407_SYSCFG_4008, + .mask_rst_msk = BIT(0) +}; + + +static struct reset_syscfg *st_restart_syscfg; + +static int st_restart(struct notifier_block *this, unsigned long mode, + void *cmd) +{ + /* reset syscfg updated */ + regmap_update_bits(st_restart_syscfg->regmap, + st_restart_syscfg->offset_rst, + st_restart_syscfg->mask_rst, + 0); + + /* unmask the reset */ + regmap_update_bits(st_restart_syscfg->regmap, + st_restart_syscfg->offset_rst_msk, + st_restart_syscfg->mask_rst_msk, + 0); + + return NOTIFY_DONE; +} + +static struct notifier_block st_restart_nb = { + .notifier_call = st_restart, + .priority = 192, +}; + +static const struct of_device_id st_reset_of_match[] = { + { + .compatible = "st,stih407-restart", + .data = (void *)&stih407_reset, + }, + {} +}; + +static int st_reset_probe(struct platform_device *pdev) +{ + struct device_node *np = pdev->dev.of_node; + const struct of_device_id *match; + struct device *dev = &pdev->dev; + + match = of_match_device(st_reset_of_match, dev); + if (!match) + return -ENODEV; + + st_restart_syscfg = (struct reset_syscfg *)match->data; + + st_restart_syscfg->regmap = + syscon_regmap_lookup_by_phandle(np, "st,syscfg"); + if (IS_ERR(st_restart_syscfg->regmap)) { + dev_err(dev, "No syscfg phandle specified\n"); + return PTR_ERR(st_restart_syscfg->regmap); + } + + return register_restart_handler(&st_restart_nb); +} + +static struct platform_driver st_reset_driver = { + .probe = st_reset_probe, + .driver = { + .name = "st_reset", + .of_match_table = st_reset_of_match, + }, +}; + +static int __init st_reset_init(void) +{ + return platform_driver_register(&st_reset_driver); +} + +device_initcall(st_reset_init); + +MODULE_AUTHOR("Christophe Kerello <christophe.kerello@st.com>"); +MODULE_DESCRIPTION("STMicroelectronics Power off Restart driver"); +MODULE_LICENSE("GPL v2"); |