remoteproc: add constraints framework

Add constraints api to remoteproc framework
supporting:

 - Latency (Using pm_qos framework)
 - Frequency
 - Bandwidth

Each of them should be provided by the specific
architecture if supported.

Change-Id: Icddd9a8ee3c6c781e1a30817a2db8716428089ad
Signed-off-by: Miguel Vadillo <vadillo@ti.com>
Signed-off-by: Fernando Guzman Lugo <fernando.lugo@ti.com>
Signed-off-by: Suman Anna <s-anna@ti.com>

3 files changed, 68 insertions, 1 deletions

diff --git a/arch/arm/mach-omap2/remoteproc.c b/arch/arm/mach-omap2/remoteproc.c
index b9b4c35..5f5cec1 100644
--- a/arch/arm/mach-omap2/remoteproc.c
+++ b/arch/arm/mach-omap2/remoteproc.c
@@ -19,7 +19,6 @@
 #include <linux/err.h>
 #include <linux/remoteproc.h>
 #include <linux/memblock.h>
-
 #include <plat/omap_device.h>
 #include <plat/omap_hwmod.h>
 #include <plat/remoteproc.h>
diff --git a/drivers/remoteproc/remoteproc.c b/drivers/remoteproc/remoteproc.c
index 7753c92..cd03896 100644
--- a/drivers/remoteproc/remoteproc.c
+++ b/drivers/remoteproc/remoteproc.c
@@ -828,6 +828,50 @@ const struct dev_pm_ops rproc_gen_pm_ops = {
 	SET_RUNTIME_PM_OPS(rproc_runtime_suspend, rproc_runtime_resume, NULL)
 };
 #endif
+int
+rproc_set_constraints(struct rproc *rproc, enum rproc_constraint type, long v)
+{
+	int ret;
+	char *cname[] = {"scale", "latency", "bandwidth"};
+	int (*func)(struct rproc *, long);
+
+	switch (type) {
+	case RPROC_CONSTRAINT_SCALE:
+		func = rproc->ops->scale;
+		break;
+	case RPROC_CONSTRAINT_LATENCY:
+		func = rproc->ops->set_lat;
+		break;
+	case RPROC_CONSTRAINT_BANDWIDTH:
+		func = rproc->ops->set_bw;
+		break;
+	default:
+		dev_err(rproc->dev, "invalid constraint\n");
+		return -EINVAL;
+	}
+
+	if (!func) {
+		dev_err(rproc->dev, "%s: no %s constraint\n",
+			__func__, cname[type]);
+		return -EINVAL;
+	}
+
+	mutex_lock(&rproc->lock);
+	if (rproc->state == RPROC_OFFLINE) {
+		pr_err("%s: rproc inactive\n", __func__);
+		mutex_unlock(&rproc->lock);
+		return -EPERM;
+	}
+
+	dev_dbg(rproc->dev, "set %s constraint %ld\n", cname[type], v);
+	ret = func(rproc, v);
+	if (ret)
+		dev_err(rproc->dev, "error %s constraint\n", cname[type]);
+	mutex_unlock(&rproc->lock);
+
+	return ret;
+}
+EXPORT_SYMBOL(rproc_set_constraints);
 
 int rproc_register(struct device *dev, const char *name,
 				const struct rproc_ops *ops,
@@ -864,6 +908,16 @@ int rproc_register(struct device *dev, const char *name,
 
 	rproc->state = RPROC_OFFLINE;
 
+	rproc->qos_request = kzalloc(sizeof(*rproc->qos_request),
+			GFP_KERNEL);
+	if (!rproc->qos_request) {
+		kfree(rproc);
+		return -ENOMEM;
+	}
+
+	pm_qos_add_request(rproc->qos_request, PM_QOS_CPU_DMA_LATENCY,
+				PM_QOS_DEFAULT_VALUE);
+
 	spin_lock(&rprocs_lock);
 	list_add_tail(&rproc->next, &rprocs);
 	spin_unlock(&rprocs_lock);
@@ -914,6 +968,8 @@ int rproc_unregister(const char *name)
 	list_del(&rproc->next);
 	spin_unlock(&rprocs_lock);
 
+	pm_qos_remove_request(rproc->qos_request);
+	kfree(rproc->qos_request);
 	kfree(rproc);
 
 	return 0;
diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
index 2dc9ec1..9fe9f0b 100644
--- a/include/linux/remoteproc.h
+++ b/include/linux/remoteproc.h
@@ -37,6 +37,7 @@
 #include <linux/completion.h>
 #include <linux/workqueue.h>
 #include <linux/notifier.h>
+#include <linux/pm_qos_params.h>
 
 /**
  * The following enums and structures define the binary format of the images
@@ -108,6 +109,12 @@ struct rproc_mem_entry {
 	u32 size;
 };
 
+enum rproc_constraint {
+	RPROC_CONSTRAINT_SCALE,
+	RPROC_CONSTRAINT_LATENCY,
+	RPROC_CONSTRAINT_BANDWIDTH,
+};
+
 struct rproc;
 
 struct rproc_ops {
@@ -117,6 +124,9 @@ struct rproc_ops {
 	int (*resume)(struct rproc *rproc);
 	int (*iommu_init)(struct rproc *, int (*)(struct rproc *, u64, u32));
 	int (*iommu_exit)(struct rproc *);
+	int (*set_lat)(struct rproc *rproc, long v);
+	int (*set_bw)(struct rproc *rproc, long v);
+	int (*scale)(struct rproc *rproc, long v);
 };
 
 /*
@@ -217,6 +227,7 @@ struct rproc {
 	struct blocking_notifier_head nb_resume;
 	struct mutex pm_lock;
 #endif
+	struct pm_qos_request_list *qos_request;
 };
 
 struct rproc *rproc_get(const char *);
@@ -234,5 +245,6 @@ extern const struct dev_pm_ops rproc_gen_pm_ops;
 #else
 #define GENERIC_RPROC_PM_OPS	NULL
 #endif
+int rproc_set_constraints(struct rproc *, enum rproc_constraint type, long v);
 
 #endif /* REMOTEPROC_H */