[PATCH 7/8] OMAP: PM CONSTRAINTS: implement wake-up latency constraints
jean.pihet at newoldbits.com
jean.pihet at newoldbits.com
Wed May 4 09:35:16 EDT 2011
From: Jean Pihet <j-pihet at 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-pihet at 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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