[PATCH 1/2] OMAP PM: create a PM layer plugin for the devices wakeup latency constraints
Kevin Hilman
khilman at ti.com
Mon Mar 7 20:09:32 EST 2011
Jean Pihet <jean.pihet at newoldbits.com> writes:
> 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>
> ---
> Based on khilman's pm-core branch
>
> 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..b8f51e3 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 "OMAP PM layer implementation, devices wakeup latency constraints"
Minor: The 'OMAP PM layer implmentatin' is redundant here as it's a sub-choice
of the OMAP PM layer menu. How abou just "per-device constraint
Kevin
> + help
> + Select this option to enable the PM layer plugin for
> + the devices wakeup latency 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 */
> +}
> +
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