Add a generic SYSCON register mapped reset mechanism. Signed-off-by: Feng Kan <fkan@xxxxxxx> --- drivers/power/reset/Kconfig | 7 +++ drivers/power/reset/Makefile | 1 + drivers/power/reset/syscon-reboot.c | 100 +++++++++++++++++++++++++++++++++++ 3 files changed, 108 insertions(+), 0 deletions(-) create mode 100644 drivers/power/reset/syscon-reboot.c diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig index fa0e4e0..9931b61 100644 --- a/drivers/power/reset/Kconfig +++ b/drivers/power/reset/Kconfig @@ -57,3 +57,10 @@ config POWER_RESET_XGENE depends on POWER_RESET help Reboot support for the APM SoC X-Gene Eval boards. + +config POWER_RESET_SYSCON + bool "Generic SYSCON regmap reset driver" + depends on MFD_SYSCON + depends on POWER_RESET + help + Reboot support for generic SYSCON mapped register reset. diff --git a/drivers/power/reset/Makefile b/drivers/power/reset/Makefile index a5b4a77..94883ed 100644 --- a/drivers/power/reset/Makefile +++ b/drivers/power/reset/Makefile @@ -5,3 +5,4 @@ obj-$(CONFIG_POWER_RESET_QNAP) += qnap-poweroff.o obj-$(CONFIG_POWER_RESET_RESTART) += restart-poweroff.o obj-$(CONFIG_POWER_RESET_VEXPRESS) += vexpress-poweroff.o obj-$(CONFIG_POWER_RESET_XGENE) += xgene-reboot.o +obj-$(CONFIG_POWER_RESET_SYSCON) += syscon-reboot.o diff --git a/drivers/power/reset/syscon-reboot.c b/drivers/power/reset/syscon-reboot.c new file mode 100644 index 0000000..29ed908 --- /dev/null +++ b/drivers/power/reset/syscon-reboot.c @@ -0,0 +1,100 @@ +/* + * Generic Syscon Reboot Driver + * + * Copyright (c) 2013, Applied Micro Circuits Corporation + * Author: Feng Kan <fkan@xxxxxxx> + * + * 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. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + * + * This driver provides system reboot functionality for APM X-Gene SoC. + * For system shutdown, this is board specify. If a board designer + * implements GPIO shutdown, use the gpio-poweroff.c driver. + */ +#include <linux/io.h> +#include <linux/of_device.h> +#include <linux/of_address.h> +#include <linux/platform_device.h> +#include <linux/stat.h> +#include <linux/slab.h> +#include <linux/mfd/syscon.h> +#include <linux/regmap.h> +#include <linux/reboot.h> +#include <asm/system_misc.h> + +struct syscon_reboot_context { + struct regmap *map; + u32 offset; + u32 mask; +}; + +static struct syscon_reboot_context *syscon_reboot_ctx; + +static void syscon_restart(enum reboot_mode reboot_mode, const char *cmd) +{ + struct syscon_reboot_context *ctx = syscon_reboot_ctx; + unsigned long timeout; + + /* Issue the reboot */ + if (ctx->map) + regmap_write(ctx->map, ctx->offset, ctx->mask); + + timeout = jiffies + HZ; + while (time_before(jiffies, timeout)) + cpu_relax(); + + pr_emerg("Unable to restart system\n"); +} + +static int syscon_reboot_probe(struct platform_device *pdev) +{ + struct syscon_reboot_context *ctx; + struct device *dev = &pdev->dev; + + ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL); + if (!ctx) { + dev_err(&pdev->dev, "out of memory for context\n"); + 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; + + arm_pm_restart = syscon_restart; + syscon_reboot_ctx = ctx; + + return 0; +} + +static 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, + }, +}; +module_platform_driver(syscon_reboot_driver); -- 1.7.6.1 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html