Merge tag 'staging-5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging

Pull staging and IIO driver updates from Greg KH:
 "Here is the big staging/iio driver update for 5.4-rc1.

  Lots of churn here, with a few driver/filesystems moving out of
  staging finally:

     - erofs moved out of staging

     - greybus core code moved out of staging

  Along with that, a new filesytem has been added:

     - extfat

  to provide support for those devices requiring that filesystem (i.e.
  transfer devices to/from windows systems or printers)

  Other than that, there a number of new IIO drivers, and lots and lots
  and lots of staging driver cleanups and minor fixes as people continue
  to dig into those for easy changes.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'staging-5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (453 commits)
  Staging: gasket: Use temporaries to reduce line length.
  Staging: octeon: Avoid several usecases of strcpy
  staging: vhciq_core: replace snprintf with scnprintf
  staging: wilc1000: avoid twice IRQ handler execution for each single interrupt
  staging: wilc1000: remove unused interrupt status handling code
  staging: fbtft: make several arrays static const, makes object smaller
  staging: rtl8188eu: make two arrays static const, makes object smaller
  staging: rtl8723bs: core: Remove Macro "IS_MAC_ADDRESS_BROADCAST"
  dt-bindings: anybus-controller: move to staging/ tree
  staging: emxx_udc: remove local TRUE/FALSE definition
  staging: wilc1000: look for rtc_clk clock
  staging: dt-bindings: wilc1000: add optional rtc_clk property
  staging: nvec: make use of devm_platform_ioremap_resource
  staging: exfat: drop unused function parameter
  Staging: exfat: Avoid use of strcpy
  staging: exfat: use integer constants
  staging: exfat: cleanup spacing for casts
  staging: exfat: cleanup spacing for operators
  staging: rtl8723bs: hal: remove redundant variable n
  staging: pi433: Fix typo in documentation
  ...

1 files changed, 197 insertions, 0 deletions

diff --git a/drivers/greybus/svc_watchdog.c b/drivers/greybus/svc_watchdog.c
new file mode 100644
index 000000000000..b6b1682c19c4
--- /dev/null
+++ b/drivers/greybus/svc_watchdog.c
@@ -0,0 +1,197 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * SVC Greybus "watchdog" driver.
+ *
+ * Copyright 2016 Google Inc.
+ */
+
+#include <linux/delay.h>
+#include <linux/suspend.h>
+#include <linux/workqueue.h>
+#include <linux/greybus.h>
+
+#define SVC_WATCHDOG_PERIOD	(2 * HZ)
+
+struct gb_svc_watchdog {
+	struct delayed_work	work;
+	struct gb_svc		*svc;
+	bool			enabled;
+	struct notifier_block pm_notifier;
+};
+
+static struct delayed_work reset_work;
+
+static int svc_watchdog_pm_notifier(struct notifier_block *notifier,
+				    unsigned long pm_event, void *unused)
+{
+	struct gb_svc_watchdog *watchdog =
+		container_of(notifier, struct gb_svc_watchdog, pm_notifier);
+
+	switch (pm_event) {
+	case PM_SUSPEND_PREPARE:
+		gb_svc_watchdog_disable(watchdog->svc);
+		break;
+	case PM_POST_SUSPEND:
+		gb_svc_watchdog_enable(watchdog->svc);
+		break;
+	default:
+		break;
+	}
+
+	return NOTIFY_DONE;
+}
+
+static void greybus_reset(struct work_struct *work)
+{
+	static char const start_path[] = "/system/bin/start";
+	static char *envp[] = {
+		"HOME=/",
+		"PATH=/sbin:/vendor/bin:/system/sbin:/system/bin:/system/xbin",
+		NULL,
+	};
+	static char *argv[] = {
+		(char *)start_path,
+		"unipro_reset",
+		NULL,
+	};
+
+	pr_err("svc_watchdog: calling \"%s %s\" to reset greybus network!\n",
+	       argv[0], argv[1]);
+	call_usermodehelper(start_path, argv, envp, UMH_WAIT_EXEC);
+}
+
+static void do_work(struct work_struct *work)
+{
+	struct gb_svc_watchdog *watchdog;
+	struct gb_svc *svc;
+	int retval;
+
+	watchdog = container_of(work, struct gb_svc_watchdog, work.work);
+	svc = watchdog->svc;
+
+	dev_dbg(&svc->dev, "%s: ping.\n", __func__);
+	retval = gb_svc_ping(svc);
+	if (retval) {
+		/*
+		 * Something went really wrong, let's warn userspace and then
+		 * pull the plug and reset the whole greybus network.
+		 * We need to do this outside of this workqueue as we will be
+		 * tearing down the svc device itself.  So queue up
+		 * yet-another-callback to do that.
+		 */
+		dev_err(&svc->dev,
+			"SVC ping has returned %d, something is wrong!!!\n",
+			retval);
+
+		if (svc->action == GB_SVC_WATCHDOG_BITE_PANIC_KERNEL) {
+			panic("SVC is not responding\n");
+		} else if (svc->action == GB_SVC_WATCHDOG_BITE_RESET_UNIPRO) {
+			dev_err(&svc->dev, "Resetting the greybus network, watch out!!!\n");
+
+			INIT_DELAYED_WORK(&reset_work, greybus_reset);
+			schedule_delayed_work(&reset_work, HZ / 2);
+
+			/*
+			 * Disable ourselves, we don't want to trip again unless
+			 * userspace wants us to.
+			 */
+			watchdog->enabled = false;
+		}
+	}
+
+	/* resubmit our work to happen again, if we are still "alive" */
+	if (watchdog->enabled)
+		schedule_delayed_work(&watchdog->work, SVC_WATCHDOG_PERIOD);
+}
+
+int gb_svc_watchdog_create(struct gb_svc *svc)
+{
+	struct gb_svc_watchdog *watchdog;
+	int retval;
+
+	if (svc->watchdog)
+		return 0;
+
+	watchdog = kmalloc(sizeof(*watchdog), GFP_KERNEL);
+	if (!watchdog)
+		return -ENOMEM;
+
+	watchdog->enabled = false;
+	watchdog->svc = svc;
+	INIT_DELAYED_WORK(&watchdog->work, do_work);
+	svc->watchdog = watchdog;
+
+	watchdog->pm_notifier.notifier_call = svc_watchdog_pm_notifier;
+	retval = register_pm_notifier(&watchdog->pm_notifier);
+	if (retval) {
+		dev_err(&svc->dev, "error registering pm notifier(%d)\n",
+			retval);
+		goto svc_watchdog_create_err;
+	}
+
+	retval = gb_svc_watchdog_enable(svc);
+	if (retval) {
+		dev_err(&svc->dev, "error enabling watchdog (%d)\n", retval);
+		unregister_pm_notifier(&watchdog->pm_notifier);
+		goto svc_watchdog_create_err;
+	}
+	return retval;
+
+svc_watchdog_create_err:
+	svc->watchdog = NULL;
+	kfree(watchdog);
+
+	return retval;
+}
+
+void gb_svc_watchdog_destroy(struct gb_svc *svc)
+{
+	struct gb_svc_watchdog *watchdog = svc->watchdog;
+
+	if (!watchdog)
+		return;
+
+	unregister_pm_notifier(&watchdog->pm_notifier);
+	gb_svc_watchdog_disable(svc);
+	svc->watchdog = NULL;
+	kfree(watchdog);
+}
+
+bool gb_svc_watchdog_enabled(struct gb_svc *svc)
+{
+	if (!svc || !svc->watchdog)
+		return false;
+	return svc->watchdog->enabled;
+}
+
+int gb_svc_watchdog_enable(struct gb_svc *svc)
+{
+	struct gb_svc_watchdog *watchdog;
+
+	if (!svc->watchdog)
+		return -ENODEV;
+
+	watchdog = svc->watchdog;
+	if (watchdog->enabled)
+		return 0;
+
+	watchdog->enabled = true;
+	schedule_delayed_work(&watchdog->work, SVC_WATCHDOG_PERIOD);
+	return 0;
+}
+
+int gb_svc_watchdog_disable(struct gb_svc *svc)
+{
+	struct gb_svc_watchdog *watchdog;
+
+	if (!svc->watchdog)
+		return -ENODEV;
+
+	watchdog = svc->watchdog;
+	if (!watchdog->enabled)
+		return 0;
+
+	watchdog->enabled = false;
+	cancel_delayed_work_sync(&watchdog->work);
+	return 0;
+}