From: Jean Pihet <j-pi...@ti.com>

Implement the wake-up latency constraints using an internal
unified function _set_dev_constraint at OMAP PM level,
which calls the corresponding function at omap device level.

The actual constraints management code is at the omap device level.

Note: the bus throughput function is implemented but currently is
a no-op.

Tested on OMAP3 Beagleboard in RET/OFF using wake-up latency constraints
on MPU, CORE and PER.

Signed-off-by: Jean Pihet <j-pi...@ti.com>
---
 arch/arm/plat-omap/omap-pm-constraints.c |  172 +++++++++++++++--------------
 1 files changed, 89 insertions(+), 83 deletions(-)

diff --git a/arch/arm/plat-omap/omap-pm-constraints.c 
b/arch/arm/plat-omap/omap-pm-constraints.c
index c8b4e4c..805dba3 100644
--- a/arch/arm/plat-omap/omap-pm-constraints.c
+++ b/arch/arm/plat-omap/omap-pm-constraints.c
@@ -24,6 +24,7 @@
 /* Interface documentation is in mach/omap-pm.h */
 #include <plat/omap-pm.h>
 #include <plat/omap_device.h>
+#include <plat/common.h>
 
 static bool off_mode_enabled;
 static u32 dummy_context_loss_counter;
@@ -32,119 +33,124 @@ static u32 dummy_context_loss_counter;
  * Device-driver-originated constraints (via board-*.c files)
  */
 
-int omap_pm_set_max_mpu_wakeup_lat(struct device *dev, long t)
+/*
+ * Generic function to omap_device layer for the constraints API.
+ */
+static int _set_dev_constraint(enum omap_pm_constraint_class class,
+                              struct device *req_dev, struct device *dev,
+                              long t)
 {
-       if (!dev || t < -1) {
+       int ret = 0;
+
+       if (!req_dev || !dev || t < -1) {
                WARN(1, "OMAP PM: %s: invalid parameter(s)", __func__);
                return -EINVAL;
-       };
-
-       if (t == -1)
-               pr_debug("OMAP PM: remove max MPU wakeup latency constraint: "
-                        "dev %s\n", dev_name(dev));
-       else
-               pr_debug("OMAP PM: add max MPU wakeup latency constraint: "
-                        "dev %s, t = %ld usec\n", dev_name(dev), t);
+       }
 
-       /*
-        * For current Linux, this needs to map the MPU to a
-        * powerdomain, then go through the list of current max lat
-        * constraints on the MPU and find the smallest.  If
-        * the latency constraint has changed, the code should
-        * recompute the state to enter for the next powerdomain
-        * state.
-        *
-        * TI CDP code can call constraint_set here.
-        */
+       /* Only valid for omap_devices */
+       if (dev->parent == &omap_device_parent) {
+               if (t == -1)
+                       pr_debug("OMAP PM: remove constraint of class %d "
+                                "from req_dev %s on dev %s\n",
+                                class, dev_name(req_dev), dev_name(dev));
+               else
+                       pr_debug("OMAP PM: add constraint of class %d "
+                                "from req_dev %s on dev %s, t = %ld\n",
+                                class, dev_name(req_dev), dev_name(dev), t);
+
+               ret = omap_device_set_dev_constraint(class, req_dev, dev, t);
+       } else {
+               pr_err("OMAP-PM: %s: Error: not an omap_device\n", __func__);
+               return -EINVAL;
+       }
 
-       return 0;
+       return ret;
 }
 
+/*
+ * omap_pm_set_min_bus_tput - set/release bus throughput constraints
+ */
 int omap_pm_set_min_bus_tput(struct device *dev, u8 agent_id, unsigned long r)
 {
+       long t;
+       struct device *req_dev = NULL;
+
        if (!dev || (agent_id != OCP_INITIATOR_AGENT &&
            agent_id != OCP_TARGET_AGENT)) {
                WARN(1, "OMAP PM: %s: invalid parameter(s)", __func__);
                return -EINVAL;
        };
 
+       /*
+        * This code calls the generic omap_device API function
+        * _set_dev_constraint with the class OMAP_PM_CONSTRAINT_THROUGHPUT.
+        * _set_dev_constraint should manage the constraints lists and call
+        * the appropriate low level code that models the interconnect,
+        * computes the required clock frequency, converts that to a VDD2
+        * OPP ID and sets the VDD2 OPP appropriately.
+        */
+
+       /*
+        * A value of r == 0 removes the constraint. Convert it to the
+        * generic _set_dev_constraint convention (-1 for constraint removal)
+        */
        if (r == 0)
-               pr_debug("OMAP PM: remove min bus tput constraint: "
-                        "dev %s for agent_id %d\n", dev_name(dev), agent_id);
+               t = -1;
        else
-               pr_debug("OMAP PM: add min bus tput constraint: "
-                        "dev %s for agent_id %d: rate %ld KiB\n",
-                        dev_name(dev), agent_id, r);
+               t = r;
 
        /*
-        * This code should model the interconnect and compute the
-        * required clock frequency, convert that to a VDD2 OPP ID, then
-        * set the VDD2 OPP appropriately.
-        *
-        * TI CDP code can call constraint_set here on the VDD2 OPP.
+        * Assign the device for L3 or L4 interconnect to req_dev,
+        * based on the value of agent_id
         */
+       switch (agent_id) {
+       case OCP_INITIATOR_AGENT:
+               req_dev = omap2_get_l3_device();
+               break;
+       case OCP_TARGET_AGENT:
+               /* Fixme: need the device for L4 interconnect */
+               break;
+       }
 
-       return 0;
+       return _set_dev_constraint(OMAP_PM_CONSTRAINT_THROUGHPUT,
+                                  req_dev, dev, t);
 }
 
+/*
+ * omap_pm_set_max_dev_wakeup_lat - set/release devices wake-up latency
+ * constraints
+ */
 int omap_pm_set_max_dev_wakeup_lat(struct device *req_dev, struct device *dev,
                                   long t)
 {
-       if (!req_dev || !dev || t < -1) {
-               WARN(1, "OMAP PM: %s: invalid parameter(s)", __func__);
-               return -EINVAL;
-       };
-
-       if (t == -1)
-               pr_debug("OMAP PM: remove max device latency constraint: "
-                        "dev %s\n", dev_name(dev));
-       else
-               pr_debug("OMAP PM: add max device latency constraint: "
-                        "dev %s, t = %ld usec\n", dev_name(dev), t);
-
-       /*
-        * For current Linux, this needs to map the device to a
-        * powerdomain, then go through the list of current max lat
-        * constraints on that powerdomain and find the smallest.  If
-        * the latency constraint has changed, the code should
-        * recompute the state to enter for the next powerdomain
-        * state.  Conceivably, this code should also determine
-        * whether to actually disable the device clocks or not,
-        * depending on how long it takes to re-enable the clocks.
-        *
-        * TI CDP code can call constraint_set here.
-        */
-
-       return 0;
+       return _set_dev_constraint(OMAP_PM_CONSTRAINT_WKUP_LAT, req_dev,
+                                  dev, t);
 }
 
-int omap_pm_set_max_sdma_lat(struct device *dev, long t)
+/*
+ * omap_pm_set_max_mpu_wakeup_lat - set/release MPU wake-up latency
+ * constraints
+ *
+ * Maps to _set_dev_constraint with OMAP_PM_CONSTRAINT_WKUP_LAT
+ * as constraint class and the MPU device as constraints target.
+ */
+int omap_pm_set_max_mpu_wakeup_lat(struct device *req_dev, long t)
 {
-       if (!dev || t < -1) {
-               WARN(1, "OMAP PM: %s: invalid parameter(s)", __func__);
-               return -EINVAL;
-       };
-
-       if (t == -1)
-               pr_debug("OMAP PM: remove max DMA latency constraint: "
-                        "dev %s\n", dev_name(dev));
-       else
-               pr_debug("OMAP PM: add max DMA latency constraint: "
-                        "dev %s, t = %ld usec\n", dev_name(dev), t);
-
-       /*
-        * For current Linux PM QOS params, this code should scan the
-        * list of maximum CPU and DMA latencies and select the
-        * smallest, then set cpu_dma_latency pm_qos_param
-        * accordingly.
-        *
-        * For future Linux PM QOS params, with separate CPU and DMA
-        * latency params, this code should just set the dma_latency param.
-        *
-        * TI CDP code can call constraint_set here.
-        */
+       return _set_dev_constraint(OMAP_PM_CONSTRAINT_WKUP_LAT, req_dev,
+                                  omap2_get_mpuss_device(), t);
+}
 
-       return 0;
+/*
+ * omap_pm_set_max_sdma_lat - set/release SDMA start latency
+ * constraints
+ *
+ * Currently maps to _set_dev_constraint with OMAP_PM_CONSTRAINT_WKUP_LAT
+ * as constraint class and the L3 device as constraints target.
+ */
+int omap_pm_set_max_sdma_lat(struct device *req_dev, long t)
+{
+       return _set_dev_constraint(OMAP_PM_CONSTRAINT_WKUP_LAT, req_dev,
+                                  omap2_get_l3_device(), t);
 }
 
 int omap_pm_set_min_clk_rate(struct device *dev, struct clk *c, long r)
-- 
1.7.2.5

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