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author | Anders Berg <anders.berg@lsi.com> | 2014-05-23 09:08:38 (GMT) |
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committer | Arnd Bergmann <arnd@arndb.de> | 2014-05-23 16:18:45 (GMT) |
commit | 4a315e3457e008e0570c392822ae98cdf7761227 (patch) | |
tree | 6e602fd67651e433571db36df7c2c86a1ffbfd85 /drivers/power/reset/axxia-reset.c | |
parent | 2baa4559ab7c934b3b6ced33e6e369081f27e7df (diff) | |
download | linux-4a315e3457e008e0570c392822ae98cdf7761227.tar.xz |
power: reset: Add Axxia system reset driver
Add Axxia (AXM55xx) SoC system reset driver. This driver handles only system
reboot (and not power-off).
Signed-off-by: Anders Berg <anders.berg@lsi.com>
Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
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 0000000..3b1f8d6 --- /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); |