linux/drivers/devfreq/tegra30-devfreq.c, branch v5.11

PM / devfreq: tegra30: Separate configurations per-SoC generation

2020-12-07T01:25:51Z

Previously we were using count-weight of the T124 for T30 in order to get EMC clock rate that was reasonable for T30. In fact the count-weight should be x2 times smaller on T30, but then devfreq was producing a bit too low EMC clock rate for ISO memory clients, like display controller for example. Now both Tegra ACTMON and Tegra DRM display drivers support interconnect framework and display driver tells to ICC what a minimum memory bandwidth is needed, preventing FIFO underflows. Thus, now we can use a proper count-weight value for Tegra30 and MC_ALL device config needs a bit more aggressive boosting. Add a separate ACTMON driver configuration that is specific to Tegra30. Tested-by: Peter Geis Tested-by: Nicolas Chauvet Acked-by: Chanwoo Choi Signed-off-by: Dmitry Osipenko Signed-off-by: Chanwoo Choi

PM / devfreq: tegra30: Support interconnect and OPPs from device-tree

2020-12-07T01:25:51Z

This patch moves ACTMON driver away from generating OPP table by itself, transitioning it to use the table which comes from device-tree. This change breaks compatibility with older device-trees and brings support for the interconnect framework to the driver. This is a mandatory change which needs to be done in order to implement interconnect-based memory DVFS, i.e. device-trees need to be updated. Now ACTMON issues a memory bandwidth requests using dev_pm_opp_set_bw() instead of driving EMC clock rate directly. Tested-by: Peter Geis Tested-by: Nicolas Chauvet Acked-by: Chanwoo Choi Signed-off-by: Dmitry Osipenko Signed-off-by: Chanwoo Choi

PM / devfreq: tegra30: Silence deferred probe error

2020-10-26T03:16:05Z

Tegra EMC driver was turned into a regular kernel driver, meaning that it could be compiled as a loadable kernel module now. Hence EMC clock isn't guaranteed to be available and clk_get("emc") may return -EPROBE_DEFER. Let's silence the deferred probe error. Acked-by: Chanwoo Choi Signed-off-by: Dmitry Osipenko Signed-off-by: Chanwoo Choi

PM / devfreq: Add governor attribute flag for specifc sysfs nodes

2020-10-26T02:46:54Z

DEVFREQ supports the default governors like performance, simple_ondemand and also allows the devfreq driver to add their own governor like tegra30-devfreq.c according to their requirement. In result, some sysfs attributes are useful or not useful. Prior to that the user can access all sysfs attributes regardless of the available attributes. So, clarify the access permission of sysfs attributes according to governor. When adding the devfreq governor, can specify the available attribute information by using DEVFREQ_GOV_ATTR_* constant variable. The user can read or write the sysfs attributes in accordance to the specified attributes. When adding the governor, can add the following attributes according to the governor feature. [Definition for speific sysfs attributes] - DEVFREQ_GOV_ATTR_POLLING_INTERVAL to update polling interval for timer. : /sys/class/devfreq/[devfreq dev name]/polling_interval - DEVFREQ_GOV_ATTR_TIMER to change the type of timer on either deferrable or dealyed timer. : /sys/class/devfreq/[devfreq dev name]/timer And all devfreq governors have to support the following common attributes. The common attributes are added to devfreq class by default. - governor - available_governors - available_frequencies - cur_freq - target_freq - min_freq - max_freq - trans_stat [Table of governor attribute flags for devfreq governors] ------------------------------------------------------------------------------ | simple | perfor | power | user | passive | tegra30 | ondemand | mance | save | space| | ------------------------------------------------------------------------------ governor | O | O | O | O | O | O available_governors | O | O | O | O | O | O available_frequencies | O | O | O | O | O | O cur_freq | O | O | O | O | O | O target_freq | O | O | O | O | O | O min_freq | O | O | O | O | O | O max_freq | O | O | O | O | O | O trans_stat | O | O | O | O | O | O -------------------------------------------------------- polling_interval | O | X | X | X | X | O timer | O | X | X | X | X | X ------------------------------------------------------------------------------ Reviewed-by: Dmitry Osipenko Tested-by: Dmitry Osipenko Signed-off-by: Chanwoo Choi

PM / devfreq: Add governor feature flag

2020-10-26T01:54:41Z

The devfreq governor is able to have the specific flag as follows in order to implement the specific feature. For example, devfreq allows user to change the governors on runtime via sysfs interface. But, if devfreq device uses 'passive' governor, don't allow user to change the governor. For this case, define the DEVFREQ_GOV_FLAG_IMMUTABLE and set it to flag of passive governor. [Definition for governor flag] - DEVFREQ_GOV_FLAG_IMMUTABLE : If immutable flag is set, governor is never changeable to other governors. - DEVFREQ_GOV_FLAG_IRQ_DRIVEN : Devfreq core won't schedule polling work for this governor if value is set. [Table of governor flag for devfreq governors] ------------------------------------------------------------------------------ | simple | perfor | power | user | passive | tegra30 | ondemand | mance | save | space| | ------------------------------------------------------------------------------ immutable | X | X | X | X | O | O interrupt_driven | X(polling)| X | X | X | X | O (irq) ------------------------------------------------------------------------------ Reviewed-by: Dmitry Osipenko Tested-by: Dmitry Osipenko Signed-off-by: Chanwoo Choi

PM / devfreq: tegra30: Improve initial hardware resetting

2020-09-29T08:50:10Z

It's safe to enable the ACTMON clock at any time during driver probing, even if we don't know the state of hardware, because it's used only for collecting and processing stats, and interrupt is kept disabled. This allows us to slightly improve code which performs initial hardware resetting by making use of a single reset_control_reset() instead of assert/deassert pair. Secondly, a potential error of the reset-control API is handled nicely now. Signed-off-by: Dmitry Osipenko Signed-off-by: Chanwoo Choi

PM / devfreq: tegra30: Disable clock on error in probe

2020-09-23T04:35:58Z

This error path needs to call clk_disable_unprepare(). Fixes: 7296443b900e ("PM / devfreq: tegra30: Handle possible round-rate error") Signed-off-by: Dan Carpenter Reviewed-by: Dmitry Osipenko Signed-off-by: Dan Carpenter Signed-off-by: Chanwoo Choi

PM / devfreq: tegra30: Delete an error message in tegra_devfreq_probe()

2020-05-28T09:02:39Z

The function “platform_get_irq” can log an error already. Thus omit a redundant message for the exception handling in the calling function. This issue was detected by using the Coccinelle software. Signed-off-by: Markus Elfring Reviewed-by: Dmitry Osipenko Signed-off-by: Chanwoo Choi

PM / devfreq: tegra30: Make CPUFreq notifier to take into account boosting

2020-05-28T09:02:39Z

We're taking into account both HW memory-accesses + CPU activity based on current CPU's frequency. For memory-accesses there is a kind of hysteresis in a form of "boosting" which is managed by the tegra30-devfreq driver. If current HW memory activity is higher than activity judged based of the CPU's frequency, then there is no need to schedule cpufreq_update_work because the result of the work will be a NO-OP. And thus, tegra_actmon_cpufreq_contribution() should return 0, meaning that at the moment CPU frequency doesn't contribute anything to the final decision about required memory clock rate. Signed-off-by: Dmitry Osipenko Signed-off-by: Chanwoo Choi

PM / devfreq: Change to DEVFREQ_GOV_UPDATE_INTERVAL event name

2020-03-24T23:35:03Z

DEVFREQ_GOV_INTERVAL event indicates that update the interval for polling mode of devfreq device. But, this event name doesn't specify exactly what to do. Change DEVFREQ_GOV_INTERVAL event name to DEVFREQ_GOV_UPDATE_INTERVAL which specifies what to do by event name. And modify the function name to DEVFREQ_GOV_UPDATE_INTERVAL with 'devfreq_' prefix + verb + object as following: - devfreq_interval_update -> devfreq_updatee_interval Reviewed-by: Lukasz Luba Signed-off-by: Chanwoo Choi