/*
* gk20a clock scaling profile
*
* Copyright (c) 2013-2015, NVIDIA Corporation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/devfreq.h>
#include <linux/debugfs.h>
#include <linux/types.h>
#include <linux/clk.h>
#include <linux/export.h>
#include <linux/slab.h>
#include <linux/clk/tegra.h>
#include <linux/tegra-soc.h>
#include <linux/platform_data/tegra_edp.h>
#include <linux/pm_qos.h>
#include <governor.h>
#include "gk20a.h"
#include "pmu_gk20a.h"
#include "clk_gk20a.h"
#include "gk20a_scale.h"
/*
* gk20a_scale_qos_notify()
*
* This function is called when the minimum QoS requirement for the device
* has changed. The function calls postscaling callback if it is defined.
*/
static int gk20a_scale_qos_notify(struct notifier_block *nb,
unsigned long n, void *p)
{
struct gk20a_scale_profile *profile =
container_of(nb, struct gk20a_scale_profile,
qos_notify_block);
struct gk20a_platform *platform = platform_get_drvdata(profile->pdev);
struct gk20a *g = get_gk20a(profile->pdev);
unsigned long freq;
if (!platform->postscale)
return NOTIFY_OK;
/* get the frequency requirement. if devfreq is enabled, check if it
* has higher demand than qos */
freq = gk20a_clk_round_rate(g, pm_qos_request(platform->qos_id));
if (g->devfreq)
freq = max(g->devfreq->previous_freq, freq);
/* Update gpu load because we may scale the emc target
* if the gpu load changed. */
gk20a_pmu_load_update(g);
platform->postscale(profile->pdev, freq);
return NOTIFY_OK;
}
/*
* gk20a_scale_make_freq_table(profile)
*
* This function initialises the frequency table for the given device profile
*/
static int gk20a_scale_make_freq_table(struct gk20a_scale_profile *profile)
{
struct gk20a *g = get_gk20a(profile->pdev);
unsigned long *freqs;
int num_freqs, err;
/* make sure the clock is available */
if (!gk20a_clk_get(g))
return -ENOSYS;
/* get gpu dvfs table */
err = tegra_dvfs_get_freqs(clk_get_parent(g->clk.tegra_clk),
&freqs, &num_freqs);
if (err)
return -ENOSYS;
profile->devfreq_profile.freq_table = (unsigned long *)freqs;
profile->devfreq_profile.max_state = num_freqs;
return 0;
}
/*
* gk20a_scale_target(dev, *freq, flags)
*
* This function scales the clock
*/
static int gk20a_scale_target(struct device *dev, unsigned long *freq,
u32 flags)
{
struct gk20a *g = get_gk20a(to_platform_device(dev));
struct gk20a_platform *platform = dev_get_drvdata(dev);
struct gk20a_scale_profile *profile = g->scale_profile;
unsigned long rounded_rate = gk20a_clk_round_rate(g, *freq);
if (gk20a_clk_get_rate(g) == rounded_rate)
*freq = rounded_rate;
else {
gk20a_clk_set_rate(g, rounded_rate);
*freq = gk20a_clk_get_rate(g);
}
/* postscale will only scale emc (dram clock) if evaluating
* gk20a_tegra_get_emc_rate() produces a new or different emc
* target because the load or_and gpufreq has changed */
if (platform->postscale)
platform->postscale(profile->pdev, rounded_rate);
return 0;
}
/*
* update_load_estimate_gpmu(profile)
*
* Update load estimate using gpmu. The gpmu value is normalised
* based on the time it was asked last time.
*/
static void update_load_estimate_gpmu(struct platform_device *pdev)
{
struct gk20a *g = get_gk20a(pdev);
struct gk20a_scale_profile *profile = g->scale_profile;
unsigned long dt;
u32 busy_time;
ktime_t t;
t = ktime_get();
dt = ktime_us_delta(t, profile->last_event_time);
profile->dev_stat.total_time = dt;
profile->last_event_time = t;
gk20a_pmu_load_norm(g, &busy_time);
profile->dev_stat.busy_time = (busy_time * dt) / 1000;
}
/*
* gk20a_scale_suspend(pdev)
*
* This function informs devfreq of suspend
*/
void gk20a_scale_suspend(struct platform_device *pdev)
{
struct gk20a *g = get_gk20a(pdev);
struct devfreq *devfreq = g->devfreq;
if (!devfreq)
return;
devfreq_suspend_device(devfreq);
}
/*
* gk20a_scale_resume(pdev)
*
* This functions informs devfreq of resume
*/
void gk20a_scale_resume(struct platform_device *pdev)
{
struct gk20a *g = get_gk20a(pdev);
struct devfreq *devfreq = g->devfreq;
if (!devfreq)
return;
devfreq_resume_device(devfreq);
}
/*
* gk20a_scale_notify(pdev, busy)
*
* Calling this function informs that the device is idling (..or busy). This
* data is used to estimate the current load
*/
static void gk20a_scale_notify(struct platform_device *pdev, bool busy)
{
struct gk20a_platform *platform = platform_get_drvdata(pdev);
struct gk20a *g = get_gk20a(pdev);
struct gk20a_scale_profile *profile = g->scale_profile;
struct devfreq *devfreq = g->devfreq;
/* update the software shadow */
gk20a_pmu_load_update(g);
/* inform edp about new constraint */
if (platform->prescale)
platform->prescale(pdev);
/* Is the device profile initialised? */
if (!(profile && devfreq))
return;
mutex_lock(&devfreq->lock);
profile->dev_stat.busy = busy;
update_devfreq(devfreq);
mutex_unlock(&devfreq->lock);
}
void gk20a_scale_notify_idle(struct platform_device *pdev)
{
gk20a_scale_notify(pdev, false);
}
void gk20a_scale_notify_busy(struct platform_device *pdev)
{
gk20a_scale_notify(pdev, true);
}
/*
* gk20a_scale_get_dev_status(dev, *stat)
*
* This function queries the current device status.
*/
static int gk20a_scale_get_dev_status(struct device *dev,
struct devfreq_dev_status *stat)
{
struct gk20a *g = get_gk20a(to_platform_device(dev));
struct gk20a_scale_profile *profile = g->scale_profile;
/* Make sure there are correct values for the current frequency */
profile->dev_stat.current_frequency = gk20a_clk_get_rate(g);
/* Update load estimate */
update_load_estimate_gpmu(to_platform_device(dev));
/* Copy the contents of the current device status */
*stat = profile->dev_stat;
/* Finally, clear out the local values */
profile->dev_stat.total_time = 0;
profile->dev_stat.busy_time = 0;
return 0;
}
/*
* gk20a_scale_init(pdev)
*/
void gk20a_scale_init(struct platform_device *pdev)
{
struct gk20a_platform *platform = platform_get_drvdata(pdev);
struct gk20a *g = platform->g;
struct gk20a_scale_profile *profile;
int err;
if (g->scale_profile)
return;
profile = kzalloc(sizeof(*profile), GFP_KERNEL);
profile->pdev = pdev;
profile->dev_stat.busy = false;
/* Create frequency table */
err = gk20a_scale_make_freq_table(profile);
if (err || !profile->devfreq_profile.max_state)
goto err_get_freqs;
/* Store device profile so we can access it if devfreq governor
* init needs that */
g->scale_profile = profile;
if (platform->devfreq_governor) {
struct devfreq *devfreq;
profile->devfreq_profile.initial_freq =
profile->devfreq_profile.freq_table[0];
profile->devfreq_profile.target = gk20a_scale_target;
profile->devfreq_profile.get_dev_status =
gk20a_scale_get_dev_status;
devfreq = devfreq_add_device(&pdev->dev,
&profile->devfreq_profile,
platform->devfreq_governor, NULL);
if (IS_ERR(devfreq))
devfreq = NULL;
g->devfreq = devfreq;
}
/* Should we register QoS callback for this device? */
if (platform->qos_id < PM_QOS_NUM_CLASSES &&
platform->qos_id != PM_QOS_RESERVED &&
platform->postscale) {
profile->qos_notify_block.notifier_call =
&gk20a_scale_qos_notify;
pm_qos_add_notifier(platform->qos_id,
&profile->qos_notify_block);
}
return;
err_get_freqs:
kfree(g->scale_profile);
g->scale_profile = NULL;
}
void gk20a_scale_exit(struct platform_device *pdev)
{
struct gk20a_platform *platform = platform_get_drvdata(pdev);
struct gk20a *g = platform->g;
int err;
if (platform->qos_id < PM_QOS_NUM_CLASSES &&
platform->qos_id != PM_QOS_RESERVED &&
platform->postscale) {
pm_qos_remove_notifier(platform->qos_id,
&g->scale_profile->qos_notify_block);
}
if (platform->devfreq_governor) {
err = devfreq_remove_device(g->devfreq);
g->devfreq = NULL;
}
kfree(g->scale_profile);
g->scale_profile = NULL;
}
/*
* gk20a_scale_hw_init(dev)
*
* Initialize hardware portion of the device
*/
void gk20a_scale_hw_init(struct platform_device *pdev)
{
struct gk20a_platform *platform = platform_get_drvdata(pdev);
struct gk20a_scale_profile *profile = platform->g->scale_profile;
/* make sure that scaling has bee initialised */
if (!profile)
return;
profile->dev_stat.total_time = 0;
profile->last_event_time = ktime_get();
}
