On 09/30/2014 04:25 PM, Feng Kan wrote:
Add a generic SYSCON register mapped reset mechanism.
Signed-off-by: Feng Kan <fkan@xxxxxxx>
---
drivers/power/reset/Kconfig | 5 ++
drivers/power/reset/Makefile | 1 +
drivers/power/reset/syscon-reboot.c | 96 +++++++++++++++++++++++++++++++++++++
3 files changed, 102 insertions(+)
create mode 100644 drivers/power/reset/syscon-reboot.c
diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig
index 1915dde..a863fa1 100644
--- a/drivers/power/reset/Kconfig
+++ b/drivers/power/reset/Kconfig
@@ -143,4 +143,9 @@ config POWER_RESET_KEYSTONE
help
Reboot support for the KEYSTONE SoCs.
+config POWER_RESET_SYSCON
+ bool "Generic SYSCON regmap reset driver"
+ depends on POWER_RESET && MFD_SYSCON && OF
Other drivers have
select MFD_SYSCON
+ help
+ Reboot support for generic SYSCON mapped register reset.
endif
diff --git a/drivers/power/reset/Makefile b/drivers/power/reset/Makefile
index 01e401d..76ce1c5 100644
--- a/drivers/power/reset/Makefile
+++ b/drivers/power/reset/Makefile
@@ -16,3 +16,4 @@ obj-$(CONFIG_POWER_RESET_VERSATILE) += arm-versatile-reboot.o
obj-$(CONFIG_POWER_RESET_VEXPRESS) += vexpress-poweroff.o
obj-$(CONFIG_POWER_RESET_XGENE) += xgene-reboot.o
obj-$(CONFIG_POWER_RESET_KEYSTONE) += keystone-reset.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..948e0ee
--- /dev/null
+++ b/drivers/power/reset/syscon-reboot.c
@@ -0,0 +1,96 @@
+/*
+ * 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.
+ */
+#include <linux/io.h>
+#include <linux/of_device.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/notifier.h>
alphabetic order of include files ?
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
+#include <linux/reboot.h>
+
+struct syscon_reboot_context {
+ struct regmap *map;
+ u32 offset;
+ u32 mask;
+ struct notifier_block restart_handler;
+};
+
+static struct syscon_reboot_context *syscon_reboot_ctx;
+
+static int syscon_restart_handle(struct notifier_block *this,
+ unsigned long mode, void *cmd)
+{
+ struct syscon_reboot_context *ctx = syscon_reboot_ctx;
Since restart_handler is part of syscon_reboot_context, you
do not need a static variable. You can use
struct syscon_reboot_context *ctx = container_of(ctx, struct syscon_reboot_context, restart_handler);
instead.
+ unsigned long timeout;
+
+ /* Issue the reboot */
+ if (ctx->map)
+ regmap_write(ctx->map, ctx->offset, ctx->mask);
+
The check for ctx->map is not needed. If the restart handler is installed,
it will always be valid.
+ timeout = jiffies + HZ;
+ while (time_before(jiffies, timeout))
+ cpu_relax();
+
jiffies won't work here, and nothing else is expected to happen.
Just use 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 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))
+ 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;
+
+ ctx->restart_handler.notifier_call = syscon_restart_handle;
+ ctx->restart_handler.priority = 128;
+ err = register_restart_handler(&ctx->restart_handler);
+ if (err)
+ dev_err(dev, "can't register restart notifier (err=%d)\n", err);
+
+ 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);
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