@@ -282,6 +282,15 @@
};
};
+ reboot_reason: reboot_reason@2a03f65c {
+ compatible = "reboot_reason";
+ reg = <0x2A03F65C 0x4>;
+ reason,none = <0x77665501>;
+ reason,bootloader = <0x77665500>;
+ reason,recovery = <0x77665502>;
+ reason,oem = <0x6f656d00>;
+ };
+
gpio-keys {
compatible = "gpio-keys";
power {
@@ -525,6 +525,14 @@ config VEXPRESS_SYSCFG
bus. System Configuration interface is one of the possible means
of generating transactions on this bus.
+config REBOOT_REASON
+ bool "Pass reboot reason to bootloader"
+ default n
+ help
+ On many systems there is a desire to provide a reboot reason to
+ the bootloader, so that the bootloader can boot into a desired
+ mode on the next boot.
+
source "drivers/misc/c2port/Kconfig"
source "drivers/misc/eeprom/Kconfig"
source "drivers/misc/cb710/Kconfig"
@@ -56,3 +56,4 @@ obj-$(CONFIG_GENWQE) += genwqe/
obj-$(CONFIG_ECHO) += echo/
obj-$(CONFIG_VEXPRESS_SYSCFG) += vexpress-syscfg.o
obj-$(CONFIG_CXL_BASE) += cxl/
+obj-$(CONFIG_REBOOT_REASON) += reboot_reason.o
new file mode 100644
@@ -0,0 +1,117 @@
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/spinlock.h>
+#include <linux/reboot.h>
+
+/* Types of reasons */
+static enum {
+ NONE,
+ BOOTLOADER,
+ RECOVERY,
+ OEM,
+ MAX_REASONS
+} __maybe_unused reason_types;
+
+static u32 reasons[MAX_REASONS];
+static void __iomem *reboot_reason_addr;
+static struct notifier_block restart_nb;
+
+static int reboot_reason(struct notifier_block *nb, unsigned long action,
+ void *data)
+{
+ char *cmd = (char *)data;
+ long reason = reasons[NONE];
+
+ if (!reboot_reason_addr)
+ return NOTIFY_DONE;
+
+ if (cmd != NULL) {
+ if (!strncmp(cmd, "bootloader", 10))
+ reason = reasons[BOOTLOADER];
+ else if (!strncmp(cmd, "recovery", 8))
+ reason = reasons[RECOVERY];
+ else if (!strncmp(cmd, "oem-", 4)) {
+ unsigned long code;
+
+ if (!kstrtoul(cmd+4, 0, &code))
+ reason = reasons[OEM] | (code & 0xff);
+ }
+ }
+
+ if (reason != -1)
+ writel(reason, reboot_reason_addr);
+ return NOTIFY_DONE;
+}
+
+static int reboot_reason_probe(struct platform_device *pdev)
+{
+ struct resource *res;
+ u32 val;
+ int i;
+
+ /* initialize the reasons */
+ for (i = 0; i < MAX_REASONS; i++)
+ reasons[i] = -1;
+
+ /* Try to grab the reason io address */
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ reboot_reason_addr = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(reboot_reason_addr))
+ return PTR_ERR(reboot_reason_addr);
+
+ /* initialize specified reasons from DT */
+ if (!of_property_read_u32(pdev->dev.of_node, "reason,none", &val))
+ reasons[NONE] = val;
+ if (!of_property_read_u32(pdev->dev.of_node, "reason,bootloader", &val))
+ reasons[BOOTLOADER] = val;
+ if (!of_property_read_u32(pdev->dev.of_node, "reason,recovery", &val))
+ reasons[RECOVERY] = val;
+ if (!of_property_read_u32(pdev->dev.of_node, "reason,oem", &val))
+ reasons[OEM] = val;
+
+ /* Install the notifier */
+ restart_nb.notifier_call = reboot_reason;
+ restart_nb.priority = 256;
+ if (register_restart_handler(&restart_nb)) {
+ dev_err(&pdev->dev,
+ "failed to setup restart handler.\n");
+ }
+ return 0;
+}
+
+int reboot_reason_remove(struct platform_device *pdev)
+{
+ unregister_restart_handler(&restart_nb);
+ return 0;
+}
+
+static const struct of_device_id reboot_reason_of_match[] = {
+ { .compatible = "reboot_reason", },
+ { },
+};
+
+static struct platform_driver reboot_reason_driver = {
+ .driver = {
+ .name = "reboot_reason",
+ .of_match_table = reboot_reason_of_match,
+ },
+ .probe = reboot_reason_probe,
+ .remove = reboot_reason_remove,
+};
+
+static int __init reboot_reason_init(void)
+{
+ return platform_driver_register(&reboot_reason_driver);
+}
+arch_initcall(reboot_reason_init);
+
+static void __exit reboot_reason_exit(void)
+{
+ platform_driver_unregister(&reboot_reason_driver);
+}
+module_exit(reboot_reason_exit);
This patch adds a basic driver to allow for commands like "reboot bootloader" and "reboot recovery" to communicate this reboot-reason to the bootloader. This is commonly done on Android devices, in order to reboot the device into fastboot or recovery mode. It also supports custom OEM specific commands, via "reboot oem-<value>". This driver pulls the phys memory address from DT as well as the magic reason values that are written to the address for each mode. For an example, this patch also adds the DT support for the nexus7 device via its dts (which is not yet upstream). Thoughts and feedback would be appreciated! Cc: Rob Herring <robh+dt@kernel.org> Cc: Pawel Moll <pawel.moll@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Ian Campbell <ijc+devicetree@hellion.org.uk> Cc: Kumar Gala <galak@codeaurora.org> Cc: Vinay Simha BN <simhavcs@gmail.com> Cc: Bjorn Andersson <bjorn.andersson@sonymobile.com> Cc: Haojian Zhuang <haojian.zhuang@linaro.org> Cc: devicetree@vger.kernel.org Cc: Android Kernel Team <kernel-team@android.com> Signed-off-by: John Stultz <john.stultz@linaro.org> --- arch/arm/boot/dts/qcom-apq8064-nexus7-flo.dts | 9 ++ drivers/misc/Kconfig | 8 ++ drivers/misc/Makefile | 1 + drivers/misc/reboot_reason.c | 117 ++++++++++++++++++++++++++ 4 files changed, 135 insertions(+) create mode 100644 drivers/misc/reboot_reason.c -- 1.9.1