[PATCH v2 1/7] OMAP PM: create a PM layer plugin for per-device constraints
Jean Pihet
jean.pihet at newoldbits.com
Thu Mar 10 12:47:21 EST 2011
Created arch/arm/plat-omap/omap-pm-constraints.c file from
arch/arm/plat-omap/omap-pm-noop.c and the associated Kconfig option
OMAP_PM_CONSTRAINTS.
Based on the original patch from Vishwanath,
cf. https://patchwork.kernel.org/patch/327312/
Cc: Vishwanath BS <vishwanath.bs at ti.com>
Signed-off-by: Jean Pihet <j-pihet at ti.com>
---
arch/arm/plat-omap/Kconfig | 7 +
arch/arm/plat-omap/Makefile | 1 +
arch/arm/plat-omap/omap-pm-constraints.c | 363 ++++++++++++++++++++++++++++++
3 files changed, 371 insertions(+), 0 deletions(-)
create mode 100644 arch/arm/plat-omap/omap-pm-constraints.c
diff --git a/arch/arm/plat-omap/Kconfig b/arch/arm/plat-omap/Kconfig
index b6333ae..22199da 100644
--- a/arch/arm/plat-omap/Kconfig
+++ b/arch/arm/plat-omap/Kconfig
@@ -215,6 +215,13 @@ config OMAP_PM_NONE
config OMAP_PM_NOOP
bool "No-op/debug PM layer"
+config OMAP_PM_CONSTRAINTS
+ depends on PM
+ bool "Per device constraints"
+ help
+ Select this option to enable the PM layer plugin for
+ the per-device constraints support
+
endchoice
endmenu
diff --git a/arch/arm/plat-omap/Makefile b/arch/arm/plat-omap/Makefile
index a4a1285..a293367 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_CONSTRAINTS) += omap-pm-constraints.o
diff --git a/arch/arm/plat-omap/omap-pm-constraints.c b/arch/arm/plat-omap/omap-pm-constraints.c
new file mode 100644
index 0000000..c8b4e4c
--- /dev/null
+++ b/arch/arm/plat-omap/omap-pm-constraints.c
@@ -0,0 +1,363 @@
+/*
+ * omap-pm.c - OMAP power management interface
+ *
+ * This code implements the OMAP power management interface to
+ * drivers, CPUIdle, CPUFreq, and DSP Bridge.
+ *
+ * Copyright (C) 2008-2009 Texas Instruments, Inc.
+ * Copyright (C) 2008-2009 Nokia Corporation
+ * Paul Walmsley
+ *
+ * Interface developed by (in alphabetical order):
+ * Karthik Dasu, Tony Lindgren, Jean Pihet, 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>
+#include <linux/platform_device.h>
+
+/* Interface documentation is in mach/omap-pm.h */
+#include <plat/omap-pm.h>
+#include <plat/omap_device.h>
+
+static bool off_mode_enabled;
+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)
+{
+ if (!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.
+ */
+
+ 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 device *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 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;
+}
+
+/**
+ * omap_pm_enable_off_mode - notify OMAP PM that off-mode is enabled
+ *
+ * Intended for use only by OMAP PM core code to notify this layer
+ * that off mode has been enabled.
+ */
+void omap_pm_enable_off_mode(void)
+{
+ off_mode_enabled = true;
+}
+
+/**
+ * omap_pm_disable_off_mode - notify OMAP PM that off-mode is disabled
+ *
+ * Intended for use only by OMAP PM core code to notify this layer
+ * that off mode has been disabled.
+ */
+void omap_pm_disable_off_mode(void)
+{
+ off_mode_enabled = false;
+}
+
+/*
+ * Device context loss tracking
+ */
+
+#ifdef CONFIG_ARCH_OMAP2PLUS
+
+u32 omap_pm_get_dev_context_loss_count(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ u32 count;
+
+ if (WARN_ON(!dev))
+ return 0;
+
+ if (dev->parent == &omap_device_parent) {
+ count = omap_device_get_context_loss_count(pdev);
+ } else {
+ WARN_ONCE(off_mode_enabled, "omap_pm: using dummy context "
+ "loss counter; device %s should be converted to "
+ "omap_device", dev_name(dev));
+ if (off_mode_enabled)
+ dummy_context_loss_counter++;
+ count = dummy_context_loss_counter;
+ }
+
+ pr_debug("OMAP PM: context loss count for dev %s = %d\n",
+ dev_name(dev), count);
+
+ return count;
+}
+
+#else
+
+u32 omap_pm_get_dev_context_loss_count(struct device *dev)
+{
+ return dummy_context_loss_counter;
+}
+
+#endif
+
+/* Should be called before clk framework init */
+int __init omap_pm_if_early_init(void)
+{
+ 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 */
+}
+
--
1.7.2.3
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