diff options
Diffstat (limited to 'drivers/power/reset/axxia-reset.c')
| -rw-r--r-- | drivers/power/reset/axxia-reset.c | 88 | 
1 files changed, 88 insertions, 0 deletions
diff --git a/drivers/power/reset/axxia-reset.c b/drivers/power/reset/axxia-reset.c new file mode 100644 index 00000000000..3b1f8d60178 --- /dev/null +++ b/drivers/power/reset/axxia-reset.c @@ -0,0 +1,88 @@ +/* + * Reset driver for Axxia devices + * + * Copyright (C) 2014 LSI + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 and + * only version 2 as published by the Free Software Foundation. + * + * 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/init.h> +#include <linux/err.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/mfd/syscon.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/reboot.h> +#include <linux/regmap.h> + +#include <asm/system_misc.h> + + +#define SC_CRIT_WRITE_KEY	0x1000 +#define SC_LATCH_ON_RESET	0x1004 +#define SC_RESET_CONTROL	0x1008 +#define   RSTCTL_RST_ZERO	(1<<3) +#define   RSTCTL_RST_FAB	(1<<2) +#define   RSTCTL_RST_CHIP	(1<<1) +#define   RSTCTL_RST_SYS	(1<<0) +#define SC_EFUSE_INT_STATUS	0x180c +#define   EFUSE_READ_DONE	(1<<31) + +static struct regmap *syscon; + +static void do_axxia_restart(enum reboot_mode reboot_mode, const char *cmd) +{ +	/* Access Key (0xab) */ +	regmap_write(syscon, SC_CRIT_WRITE_KEY, 0xab); +	/* Select internal boot from 0xffff0000 */ +	regmap_write(syscon, SC_LATCH_ON_RESET, 0x00000040); +	/* Assert ResetReadDone (to avoid hanging in boot ROM) */ +	regmap_write(syscon, SC_EFUSE_INT_STATUS, EFUSE_READ_DONE); +	/* Assert chip reset */ +	regmap_update_bits(syscon, SC_RESET_CONTROL, +			   RSTCTL_RST_CHIP, RSTCTL_RST_CHIP); +} + +static int axxia_reset_probe(struct platform_device *pdev) +{ +	struct device *dev = &pdev->dev; + +	syscon = syscon_regmap_lookup_by_phandle(dev->of_node, "syscon"); +	if (IS_ERR(syscon)) { +		pr_err("%s: syscon lookup failed\n", dev->of_node->name); +		return PTR_ERR(syscon); +	} + +	arm_pm_restart = do_axxia_restart; + +	return 0; +} + +static const struct of_device_id of_axxia_reset_match[] = { +	{ .compatible = "lsi,axm55xx-reset", }, +	{}, +}; +MODULE_DEVICE_TABLE(of, of_axxia_reset_match); + +static struct platform_driver axxia_reset_driver = { +	.probe = axxia_reset_probe, +	.driver = { +		.name = "axxia-reset", +		.of_match_table = of_match_ptr(of_axxia_reset_match), +	}, +}; + +static int __init axxia_reset_init(void) +{ +	return platform_driver_register(&axxia_reset_driver); +} +device_initcall(axxia_reset_init);  | 
