[PATCH] OMAP PM: MPU/DMA Latency constraints

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This patch has implementation for OMAP MPU/DMA Latency constraints using PM QOS.

Signed-off-by: Vishwanath Sripathy <vishwanath.bs@xxxxxx>
---
 arch/arm/plat-omap/Kconfig                |    3 +
 arch/arm/plat-omap/Makefile               |    1 +
 arch/arm/plat-omap/i2c.c                  |    3 +-
 arch/arm/plat-omap/include/plat/omap-pm.h |    9 +-
 arch/arm/plat-omap/omap-pm-noop.c         |   20 +--
 arch/arm/plat-omap/omap-pm.c              |  309 +++++++++++++++++++++++++++++
 6 files changed, 328 insertions(+), 17 deletions(-)
 create mode 100755 arch/arm/plat-omap/omap-pm.c

diff --git a/arch/arm/plat-omap/Kconfig b/arch/arm/plat-omap/Kconfig
index 286b606..ce544b0 100644
--- a/arch/arm/plat-omap/Kconfig
+++ b/arch/arm/plat-omap/Kconfig
@@ -194,6 +194,9 @@ config OMAP_PM_NONE
 config OMAP_PM_NOOP
 	bool "No-op/debug PM layer"
 
+config OMAP_PM
+	depends on PM
+	bool "OMAP PM layer implementation"
 endchoice
 
 endmenu
diff --git a/arch/arm/plat-omap/Makefile b/arch/arm/plat-omap/Makefile
index 2a15191..fad2475 100644
--- a/arch/arm/plat-omap/Makefile
+++ b/arch/arm/plat-omap/Makefile
@@ -32,3 +32,4 @@ obj-y += $(i2c-omap-m) $(i2c-omap-y)
 obj-$(CONFIG_OMAP_MBOX_FWK) += mailbox.o
 
 obj-$(CONFIG_OMAP_PM_NOOP) += omap-pm-noop.o
+obj-$(CONFIG_OMAP_PM) += omap-pm.o
diff --git a/arch/arm/plat-omap/i2c.c b/arch/arm/plat-omap/i2c.c
index a5ce4f0..29dc45a
--- a/arch/arm/plat-omap/i2c.c
+++ b/arch/arm/plat-omap/i2c.c
@@ -145,7 +145,8 @@ static inline int omap1_i2c_add_bus(struct platform_device *pdev, int bus_id)
  */
 static void omap_pm_set_max_mpu_wakeup_lat_compat(struct device *dev, long t)
 {
-	omap_pm_set_max_mpu_wakeup_lat(dev, t);
+	struct pm_qos_request_list *qos_handle = NULL;
+	omap_pm_set_max_mpu_wakeup_lat(&qos_handle, t);
 }
 
 static inline int omap2_i2c_add_bus(struct platform_device *pdev, int bus_id)
diff --git a/arch/arm/plat-omap/include/plat/omap-pm.h b/arch/arm/plat-omap/include/plat/omap-pm.h
index 728fbb9..47ba9e6 100644
--- a/arch/arm/plat-omap/include/plat/omap-pm.h
+++ b/arch/arm/plat-omap/include/plat/omap-pm.h
@@ -19,6 +19,7 @@
 #include <linux/clk.h>
 
 #include "powerdomain.h"
+#include <linux/pm_qos_params.h>
 
 /**
  * struct omap_opp - clock frequency-to-OPP ID table for DSP, MPU
@@ -86,7 +87,7 @@ void omap_pm_if_exit(void);
 
 /**
  * omap_pm_set_max_mpu_wakeup_lat - set the maximum MPU wakeup latency
- * @dev: struct device * requesting the constraint
+ * @qos_request: handle for the constraint. The pointer should be initialized to NULL
  * @t: maximum MPU wakeup latency in microseconds
  *
  * Request that the maximum interrupt latency for the MPU to be no
@@ -118,7 +119,7 @@ void omap_pm_if_exit(void);
  * Returns -EINVAL for an invalid argument, -ERANGE if the constraint
  * is not satisfiable, or 0 upon success.
  */
-int omap_pm_set_max_mpu_wakeup_lat(struct device *dev, long t);
+int omap_pm_set_max_mpu_wakeup_lat(struct pm_qos_request_list **qos_request, long t);
 
 
 /**
@@ -185,7 +186,7 @@ int omap_pm_set_max_dev_wakeup_lat(struct device *req_dev, struct device *dev,
 
 /**
  * omap_pm_set_max_sdma_lat - set the maximum system DMA transfer start latency
- * @dev: struct device *
+ * @qos_request: handle for the constraint. The pointer should be initialized to NULL
  * @t: maximum DMA transfer start latency in microseconds
  *
  * Request that the maximum system DMA transfer start latency for this
@@ -210,7 +211,7 @@ int omap_pm_set_max_dev_wakeup_lat(struct device *req_dev, struct device *dev,
  * Returns -EINVAL for an invalid argument, -ERANGE if the constraint
  * is not satisfiable, or 0 upon success.
  */
-int omap_pm_set_max_sdma_lat(struct device *dev, long t);
+int omap_pm_set_max_sdma_lat(struct pm_qos_request_list **qos_request, long t);
 
 
 /**
diff --git a/arch/arm/plat-omap/omap-pm-noop.c b/arch/arm/plat-omap/omap-pm-noop.c
index e129ce8..af2fe43 100644
--- a/arch/arm/plat-omap/omap-pm-noop.c
+++ b/arch/arm/plat-omap/omap-pm-noop.c
@@ -34,19 +34,17 @@ struct omap_opp *l3_opps;
  * Device-driver-originated constraints (via board-*.c files)
  */
 
-int omap_pm_set_max_mpu_wakeup_lat(struct device *dev, long t)
+int omap_pm_set_max_mpu_wakeup_lat(struct pm_qos_request_list **pmqos_req, long t)
 {
-	if (!dev || t < -1) {
+	if (!pmqos_req || 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));
+		pr_debug("OMAP PM: remove max MPU wakeup latency constraint\n");
 	else
-		pr_debug("OMAP PM: add max MPU wakeup latency constraint: "
-			 "dev %s, t = %ld usec\n", dev_name(dev), t);
+		pr_debug("OMAP PM: add max MPU wakeup latency constraint: t = %ld usec\n", t);
 
 	/*
 	 * For current Linux, this needs to map the MPU to a
@@ -120,19 +118,17 @@ int omap_pm_set_max_dev_wakeup_lat(struct device *req_dev, struct device *dev,
 	return 0;
 }
 
-int omap_pm_set_max_sdma_lat(struct device *dev, long t)
+int omap_pm_set_max_sdma_lat(struct pm_qos_request_list **qos_request, long t)
 {
-	if (!dev || t < -1) {
+	if (!qos_request || 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));
+		pr_debug("OMAP PM: remove max DMA latency constraint:\n");
 	else
-		pr_debug("OMAP PM: add max DMA latency constraint: "
-			 "dev %s, t = %ld usec\n", dev_name(dev), t);
+		pr_debug("OMAP PM: add max DMA latency constraint: t = %ld usec\n", t);
 
 	/*
 	 * For current Linux PM QOS params, this code should scan the
diff --git a/arch/arm/plat-omap/omap-pm.c b/arch/arm/plat-omap/omap-pm.c
new file mode 100755
index 0000000..937196a
--- /dev/null
+++ b/arch/arm/plat-omap/omap-pm.c
@@ -0,0 +1,309 @@
+/*
+ * omap-pm.c - OMAP power management interface
+ *
+ * Copyright (C) 2008-2010 Texas Instruments, Inc.
+ * Copyright (C) 2008-2009 Nokia Corporation
+ * Vishwanath BS
+ *
+ * This code is based on plat-omap/omap-pm-noop.c.
+ *
+ * Interface developed by (in alphabetical order):
+ * Karthik Dasu, Tony Lindgren, Rajendra Nayak, Sakari Poussa, Veeramanikandan
+ * Raju, Anand Sawant, Igor Stoppa, Paul Walmsley, Richard Woodruff
+ */
+
+#undef DEBUG
+
+#include <linux/init.h>
+#include <linux/cpufreq.h>
+#include <linux/device.h>
+
+/* Interface documentation is in mach/omap-pm.h */
+#include <plat/omap-pm.h>
+
+#include <plat/powerdomain.h>
+
+struct omap_opp *dsp_opps;
+struct omap_opp *mpu_opps;
+struct omap_opp *l3_opps;
+
+/*
+ * Device-driver-originated constraints (via board-*.c files)
+ */
+
+int omap_pm_set_max_mpu_wakeup_lat(struct pm_qos_request_list **qos_request, long t)
+{
+	if (!qos_request || t < -1) {
+		pr_warning("Warning: invalid params to omap_pm_set_max_mpu_wakeup_lat \n:");
+		return -EINVAL;
+	};
+
+	if (t == -1) {
+		pm_qos_remove_request(*qos_request);
+		*qos_request = NULL;
+	} else if (*qos_request == NULL)
+		*qos_request = pm_qos_add_request(PM_QOS_CPU_DMA_LATENCY, t);
+	else
+		pm_qos_update_request(*qos_request, t);
+
+	return 0;
+}
+
+
+int omap_pm_set_min_bus_tput(struct device *dev, u8 agent_id, unsigned long r)
+{
+	if (!dev || (agent_id != OCP_INITIATOR_AGENT &&
+	    agent_id != OCP_TARGET_AGENT)) {
+		WARN(1, "OMAP PM: %s: invalid parameter(s)", __func__);
+		return -EINVAL;
+	};
+
+	if (r == 0)
+		pr_debug("OMAP PM: remove min bus tput constraint: "
+			 "dev %s for agent_id %d\n", dev_name(dev), agent_id);
+	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);
+
+	/*
+	 * 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.
+	 */
+
+	return 0;
+}
+
+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;
+}
+
+int omap_pm_set_max_sdma_lat(struct pm_qos_request_list **qos_request, long t)
+{
+	if (!qos_request || t < -1) {
+		pr_warning("Warning: invalid params to omap_pm_set_max_sdma_lat\n:");
+		return -EINVAL;
+	};
+
+	if (t == -1) {
+		pm_qos_remove_request(*qos_request);
+		*qos_request = NULL;
+	} else if (*qos_request == NULL)
+		*qos_request = pm_qos_add_request(PM_QOS_CPU_DMA_LATENCY, t);
+	else
+		pm_qos_update_request(*qos_request, t);
+
+	return 0;
+}
+
+int omap_pm_set_min_clk_rate(struct device *dev, struct clk *c, long r)
+{
+	if (!dev || !c || r < 0) {
+		WARN(1, "OMAP PM: %s: invalid parameter(s)", __func__);
+		return -EINVAL;
+	}
+
+	if (r == 0)
+		pr_debug("OMAP PM: remove min clk rate constraint: "
+			 "dev %s\n", dev_name(dev));
+	else
+		pr_debug("OMAP PM: add min clk rate constraint: "
+			 "dev %s, rate = %ld Hz\n", dev_name(dev), r);
+
+	/*
+	 * Code in a real implementation should keep track of these
+	 * constraints on the clock, and determine the highest minimum
+	 * clock rate.  It should iterate over each OPP and determine
+	 * whether the OPP will result in a clock rate that would
+	 * satisfy this constraint (and any other PM constraint in effect
+	 * at that time).  Once it finds the lowest-voltage OPP that
+	 * meets those conditions, it should switch to it, or return
+	 * an error if the code is not capable of doing so.
+	 */
+
+	return 0;
+}
+
+/*
+ * DSP Bridge-specific constraints
+ */
+
+const struct omap_opp *omap_pm_dsp_get_opp_table(void)
+{
+	pr_debug("OMAP PM: DSP request for OPP table\n");
+
+	/*
+	 * Return DSP frequency table here:  The final item in the
+	 * array should have .rate = .opp_id = 0.
+	 */
+
+	return NULL;
+}
+
+void omap_pm_dsp_set_min_opp(u8 opp_id)
+{
+	if (opp_id == 0) {
+		WARN_ON(1);
+		return;
+	}
+
+	pr_debug("OMAP PM: DSP requests minimum VDD1 OPP to be %d\n", opp_id);
+
+	/*
+	 *
+	 * For l-o dev tree, our VDD1 clk is keyed on OPP ID, so we
+	 * can just test to see which is higher, the CPU's desired OPP
+	 * ID or the DSP's desired OPP ID, and use whichever is
+	 * highest.
+	 *
+	 * In CDP12.14+, the VDD1 OPP custom clock that controls the DSP
+	 * rate is keyed on MPU speed, not the OPP ID.  So we need to
+	 * map the OPP ID to the MPU speed for use with clk_set_rate()
+	 * if it is higher than the current OPP clock rate.
+	 *
+	 */
+}
+
+
+u8 omap_pm_dsp_get_opp(void)
+{
+	pr_debug("OMAP PM: DSP requests current DSP OPP ID\n");
+
+	/*
+	 * For l-o dev tree, call clk_get_rate() on VDD1 OPP clock
+	 *
+	 * CDP12.14+:
+	 * Call clk_get_rate() on the OPP custom clock, map that to an
+	 * OPP ID using the tables defined in board-*.c/chip-*.c files.
+	 */
+
+	return 0;
+}
+
+/*
+ * CPUFreq-originated constraint
+ *
+ * In the future, this should be handled by custom OPP clocktype
+ * functions.
+ */
+
+struct cpufreq_frequency_table **omap_pm_cpu_get_freq_table(void)
+{
+	pr_debug("OMAP PM: CPUFreq request for frequency table\n");
+
+	/*
+	 * Return CPUFreq frequency table here: loop over
+	 * all VDD1 clkrates, pull out the mpu_ck frequencies, build
+	 * table
+	 */
+
+	return NULL;
+}
+
+void omap_pm_cpu_set_freq(unsigned long f)
+{
+	if (f == 0) {
+		WARN_ON(1);
+		return;
+	}
+
+	pr_debug("OMAP PM: CPUFreq requests CPU frequency to be set to %lu\n",
+		 f);
+
+	/*
+	 * For l-o dev tree, determine whether MPU freq or DSP OPP id
+	 * freq is higher.  Find the OPP ID corresponding to the
+	 * higher frequency.  Call clk_round_rate() and clk_set_rate()
+	 * on the OPP custom clock.
+	 *
+	 * CDP should just be able to set the VDD1 OPP clock rate here.
+	 */
+}
+
+unsigned long omap_pm_cpu_get_freq(void)
+{
+	pr_debug("OMAP PM: CPUFreq requests current CPU frequency\n");
+
+	/*
+	 * Call clk_get_rate() on the mpu_ck.
+	 */
+
+	return 0;
+}
+
+/*
+ * Device context loss tracking
+ */
+
+int omap_pm_get_dev_context_loss_count(struct device *dev)
+{
+	if (!dev) {
+		WARN_ON(1);
+		return -EINVAL;
+	};
+
+	pr_debug("OMAP PM: returning context loss count for dev %s\n",
+		 dev_name(dev));
+
+	/*
+	 * Map the device to the powerdomain.  Return the powerdomain
+	 * off counter.
+	 */
+
+	return 0;
+}
+
+
+/* Should be called before clk framework init */
+int __init omap_pm_if_early_init(struct omap_opp *mpu_opp_table,
+				 struct omap_opp *dsp_opp_table,
+				 struct omap_opp *l3_opp_table)
+{
+	mpu_opps = mpu_opp_table;
+	dsp_opps = dsp_opp_table;
+	l3_opps = l3_opp_table;
+	return 0;
+}
+
+/* Must be called after clock framework is initialized */
+int __init omap_pm_if_init(void)
+{
+	return 0;
+}
+
+void omap_pm_if_exit(void)
+{
+	/* Deallocate CPUFreq frequency table here */
+}
+
+
-- 
1.5.4.7

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