Merge tag 'stm-for-greg-20160701' of git://git.kernel.org/pub/scm/linux/kernel/git/ash/stm into char-misc-testing

Alexander writes:

stm class/intel_th: Updates for 4.8

These are:
 * runtime power management implementation for both intel_th and stm class
 * semi-random kerneldoc fixes

drivers/hwtracing/intel_th/core.c

@@ -23,6 +23,7 @@
 #include <linux/debugfs.h>
 #include <linux/idr.h>
 #include <linux/pci.h>
+#include <linux/pm_runtime.h>
 #include <linux/dma-mapping.h>
 
 #include "intel_th.h"
@@ -67,23 +68,33 @@ static int intel_th_probe(struct device *dev)
 
 	hubdrv = to_intel_th_driver(hub->dev.driver);
 
+	pm_runtime_set_active(dev);
+	pm_runtime_no_callbacks(dev);
+	pm_runtime_enable(dev);
+
 	ret = thdrv->probe(to_intel_th_device(dev));
 	if (ret)
-		return ret;
+		goto out_pm;
 
 	if (thdrv->attr_group) {
 		ret = sysfs_create_group(&thdev->dev.kobj, thdrv->attr_group);
-		if (ret) {
-			thdrv->remove(thdev);
-
-			return ret;
-		}
+		if (ret)
+			goto out;
 	}
 
 	if (thdev->type == INTEL_TH_OUTPUT &&
 	    !intel_th_output_assigned(thdev))
+		/* does not talk to hardware */
 		ret = hubdrv->assign(hub, thdev);
 
+out:
+	if (ret)
+		thdrv->remove(thdev);
+
+out_pm:
+	if (ret)
+		pm_runtime_disable(dev);
+
 	return ret;
 }
 
@@ -103,6 +114,8 @@ static int intel_th_remove(struct device *dev)
 	if (thdrv->attr_group)
 		sysfs_remove_group(&thdev->dev.kobj, thdrv->attr_group);
 
+	pm_runtime_get_sync(dev);
+
 	thdrv->remove(thdev);
 
 	if (intel_th_output_assigned(thdev)) {
@@ -110,9 +123,14 @@ static int intel_th_remove(struct device *dev)
 			to_intel_th_driver(dev->parent->driver);
 
 		if (hub->dev.driver)
+			/* does not talk to hardware */
 			hubdrv->unassign(hub, thdev);
 	}
 
+	pm_runtime_disable(dev);
+	pm_runtime_set_active(dev);
+	pm_runtime_enable(dev);
+
 	return 0;
 }
 
@@ -185,6 +203,7 @@ static int intel_th_output_activate(struct intel_th_device *thdev)
 {
 	struct intel_th_driver *thdrv =
 		to_intel_th_driver_or_null(thdev->dev.driver);
+	int ret = 0;
 
 	if (!thdrv)
 		return -ENODEV;
@@ -192,12 +211,17 @@ static int intel_th_output_activate(struct intel_th_device *thdev)
 	if (!try_module_get(thdrv->driver.owner))
 		return -ENODEV;
 
+	pm_runtime_get_sync(&thdev->dev);
+
 	if (thdrv->activate)
-		return thdrv->activate(thdev);
+		ret = thdrv->activate(thdev);
+	else
+		intel_th_trace_enable(thdev);
 
-	intel_th_trace_enable(thdev);
+	if (ret)
+		pm_runtime_put(&thdev->dev);
 
-	return 0;
+	return ret;
 }
 
 static void intel_th_output_deactivate(struct intel_th_device *thdev)
@@ -213,6 +237,7 @@ static void intel_th_output_deactivate(struct intel_th_device *thdev)
 	else
 		intel_th_trace_disable(thdev);
 
+	pm_runtime_put(&thdev->dev);
 	module_put(thdrv->driver.owner);
 }
 
@@ -628,6 +653,10 @@ intel_th_alloc(struct device *dev, struct resource *devres,
 
 	dev_set_drvdata(dev, th);
 
+	pm_runtime_no_callbacks(dev);
+	pm_runtime_put(dev);
+	pm_runtime_allow(dev);
+
 	err = intel_th_populate(th, devres, ndevres, irq);
 	if (err)
 		goto err_chrdev;
@@ -635,6 +664,8 @@ intel_th_alloc(struct device *dev, struct resource *devres,
 	return th;
 
 err_chrdev:
+	pm_runtime_forbid(dev);
+
 	__unregister_chrdev(th->major, 0, TH_POSSIBLE_OUTPUTS,
 			    "intel_th/output");
 
@@ -658,6 +689,9 @@ void intel_th_free(struct intel_th *th)
 
 	intel_th_device_remove(th->hub);
 
+	pm_runtime_get_sync(th->dev);
+	pm_runtime_forbid(th->dev);
+
 	__unregister_chrdev(th->major, 0, TH_POSSIBLE_OUTPUTS,
 			    "intel_th/output");
 
@@ -682,6 +716,7 @@ int intel_th_trace_enable(struct intel_th_device *thdev)
 	if (WARN_ON_ONCE(thdev->type != INTEL_TH_OUTPUT))
 		return -EINVAL;
 
+	pm_runtime_get_sync(&thdev->dev);
 	hubdrv->enable(hub, &thdev->output);
 
 	return 0;
@@ -702,6 +737,7 @@ int intel_th_trace_disable(struct intel_th_device *thdev)
 		return -EINVAL;
 
 	hubdrv->disable(hub, &thdev->output);
+	pm_runtime_put(&thdev->dev);
 
 	return 0;
 }

drivers/hwtracing/intel_th/gth.c

@@ -22,6 +22,7 @@
 #include <linux/mm.h>
 #include <linux/slab.h>
 #include <linux/bitmap.h>
+#include <linux/pm_runtime.h>
 
 #include "intel_th.h"
 #include "gth.h"
@@ -190,6 +191,11 @@ static ssize_t master_attr_store(struct device *dev,
 	if (old_port >= 0) {
 		gth->master[ma->master] = -1;
 		clear_bit(ma->master, gth->output[old_port].master);
+
+		/*
+		 * if the port is active, program this setting,
+		 * implies that runtime PM is on
+		 */
 		if (gth->output[old_port].output->active)
 			gth_master_set(gth, ma->master, -1);
 	}
@@ -204,7 +210,7 @@ static ssize_t master_attr_store(struct device *dev,
 
 		set_bit(ma->master, gth->output[port].master);
 
-		/* if the port is active, program this setting */
+		/* if the port is active, program this setting, see above */
 		if (gth->output[port].output->active)
 			gth_master_set(gth, ma->master, port);
 	}
@@ -326,11 +332,15 @@ static ssize_t output_attr_show(struct device *dev,
 	struct gth_device *gth = oa->gth;
 	size_t count;
 
+	pm_runtime_get_sync(dev);
+
 	spin_lock(&gth->gth_lock);
 	count = snprintf(buf, PAGE_SIZE, "%x\n",
 			 gth_output_parm_get(gth, oa->port, oa->parm));
 	spin_unlock(&gth->gth_lock);
 
+	pm_runtime_put(dev);
+
 	return count;
 }
 
@@ -346,10 +356,14 @@ static ssize_t output_attr_store(struct device *dev,
 	if (kstrtouint(buf, 16, &config) < 0)
 		return -EINVAL;
 
+	pm_runtime_get_sync(dev);
+
 	spin_lock(&gth->gth_lock);
 	gth_output_parm_set(gth, oa->port, oa->parm, config);
 	spin_unlock(&gth->gth_lock);
 
+	pm_runtime_put(dev);
+
 	return count;
 }
 
@@ -451,7 +465,7 @@ static int intel_th_output_attributes(struct gth_device *gth)
 }
 
 /**
- * intel_th_gth_disable() - enable tracing to an output device
+ * intel_th_gth_disable() - disable tracing to an output device
  * @thdev:	GTH device
  * @output:	output device's descriptor
  *

drivers/hwtracing/intel_th/intel_th.h

@@ -114,6 +114,9 @@ intel_th_output_assigned(struct intel_th_device *thdev)
  * @unassign:	deassociate an output type device from an output port
  * @enable:	enable tracing for a given output device
  * @disable:	disable tracing for a given output device
+ * @irq:	interrupt callback
+ * @activate:	enable tracing on the output's side
+ * @deactivate:	disable tracing on the output's side
  * @fops:	file operations for device nodes
  * @attr_group:	attributes provided by the driver
  *

drivers/hwtracing/stm/core.c

@@ -15,6 +15,7 @@
  * as defined in MIPI STPv2 specification.
  */
 
+#include <linux/pm_runtime.h>
 #include <linux/uaccess.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
@@ -482,14 +483,40 @@ static ssize_t stm_char_write(struct file *file, const char __user *buf,
 		return -EFAULT;
 	}
 
+	pm_runtime_get_sync(&stm->dev);
+
 	count = stm_write(stm->data, stmf->output.master, stmf->output.channel,
 			  kbuf, count);
 
+	pm_runtime_mark_last_busy(&stm->dev);
+	pm_runtime_put_autosuspend(&stm->dev);
 	kfree(kbuf);
 
 	return count;
 }
 
+static void stm_mmap_open(struct vm_area_struct *vma)
+{
+	struct stm_file *stmf = vma->vm_file->private_data;
+	struct stm_device *stm = stmf->stm;
+
+	pm_runtime_get(&stm->dev);
+}
+
+static void stm_mmap_close(struct vm_area_struct *vma)
+{
+	struct stm_file *stmf = vma->vm_file->private_data;
+	struct stm_device *stm = stmf->stm;
+
+	pm_runtime_mark_last_busy(&stm->dev);
+	pm_runtime_put_autosuspend(&stm->dev);
+}
+
+static const struct vm_operations_struct stm_mmap_vmops = {
+	.open	= stm_mmap_open,
+	.close	= stm_mmap_close,
+};
+
 static int stm_char_mmap(struct file *file, struct vm_area_struct *vma)
 {
 	struct stm_file *stmf = file->private_data;
@@ -514,8 +541,11 @@ static int stm_char_mmap(struct file *file, struct vm_area_struct *vma)
 	if (!phys)
 		return -EINVAL;
 
+	pm_runtime_get_sync(&stm->dev);
+
 	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 	vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP;
+	vma->vm_ops = &stm_mmap_vmops;
 	vm_iomap_memory(vma, phys, size);
 
 	return 0;
@@ -701,6 +731,17 @@ int stm_register_device(struct device *parent, struct stm_data *stm_data,
 	if (err)
 		goto err_device;
 
+	/*
+	 * Use delayed autosuspend to avoid bouncing back and forth
+	 * on recurring character device writes, with the initial
+	 * delay time of 2 seconds.
+	 */
+	pm_runtime_no_callbacks(&stm->dev);
+	pm_runtime_use_autosuspend(&stm->dev);
+	pm_runtime_set_autosuspend_delay(&stm->dev, 2000);
+	pm_runtime_set_suspended(&stm->dev);
+	pm_runtime_enable(&stm->dev);
+
 	return 0;
 
 err_device:
@@ -724,6 +765,9 @@ void stm_unregister_device(struct stm_data *stm_data)
 	struct stm_source_device *src, *iter;
 	int i, ret;
 
+	pm_runtime_dont_use_autosuspend(&stm->dev);
+	pm_runtime_disable(&stm->dev);
+
 	mutex_lock(&stm->link_mutex);
 	list_for_each_entry_safe(src, iter, &stm->link_list, link_entry) {
 		ret = __stm_source_link_drop(src, stm);
@@ -878,6 +922,8 @@ static int __stm_source_link_drop(struct stm_source_device *src,
 
 	stm_output_free(link, &src->output);
 	list_del_init(&src->link_entry);
+	pm_runtime_mark_last_busy(&link->dev);
+	pm_runtime_put_autosuspend(&link->dev);
 	/* matches stm_find_device() from stm_source_link_store() */
 	stm_put_device(link);
 	rcu_assign_pointer(src->link, NULL);
@@ -971,8 +1017,11 @@ static ssize_t stm_source_link_store(struct device *dev,
 	if (!link)
 		return -EINVAL;
 
+	pm_runtime_get(&link->dev);
+
 	err = stm_source_link_add(src, link);
 	if (err) {
+		pm_runtime_put_autosuspend(&link->dev);
 		/* matches the stm_find_device() above */
 		stm_put_device(link);
 	}
@@ -1033,6 +1082,9 @@ int stm_source_register_device(struct device *parent,
 	if (err)
 		goto err;
 
+	pm_runtime_no_callbacks(&src->dev);
+	pm_runtime_forbid(&src->dev);
+
 	err = device_add(&src->dev);
 	if (err)
 		goto err;