| Message ID | 20180614194712.102134-12-mka@chromium.org (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
Hi, On Thu, Jun 14, 2018 at 12:47:11PM -0700, Matthias Kaehlcke wrote: > The driver subscribes to throttling events from the Chrome OS > embedded controller and enables/disables system throttling based > on these events. > > Signed-off-by: Matthias Kaehlcke <mka@chromium.org> > Reviewed-by: Enric Balletbo i Serra <enric.balletbo@collabora.com> One suggestion, and otherwise: Reviewed-by: Brian Norris <briannorris@chromium.org> > --- > Changes in v3: > - change module license to GPL v2 as in the SPDX identifier > - don't instantiate the throttler through the DT (instantiation > by CrOS EC MFD in a separate patch) > > Changes in v2: > - added SPDX line instead of license boiler-plate > - use macro to avoid splitting line > - changed variable name for throttler from 'cte' to 'ce_thr' > - formatting fixes > - Kconfig: removed odd dashes around 'help' > - added 'Reviewed-by' tag > > drivers/misc/throttler/Kconfig | 10 ++ > drivers/misc/throttler/Makefile | 1 + > drivers/misc/throttler/cros_ec_throttler.c | 109 +++++++++++++++++++++ > 3 files changed, 120 insertions(+) > create mode 100644 drivers/misc/throttler/cros_ec_throttler.c > > diff --git a/drivers/misc/throttler/Kconfig b/drivers/misc/throttler/Kconfig > index 8b2e63b2ef48..ef984c96f67b 100644 > --- a/drivers/misc/throttler/Kconfig > +++ b/drivers/misc/throttler/Kconfig > @@ -20,4 +20,14 @@ menuconfig THROTTLER_DEBUG > > Choose N unless you want to debug throttler drivers. > > +config CROS_EC_THROTTLER > + tristate "Throttler event monitor for the Chrome OS Embedded Controller" > + depends on MFD_CROS_EC > + help > + This driver adds support to throttle the system in reaction to > + Chrome OS EC events. > + > + To compile this driver as a module, choose M here: the > + module will be called cros_ec_throttler. > + > endif # THROTTLER > diff --git a/drivers/misc/throttler/Makefile b/drivers/misc/throttler/Makefile > index c8d920cee315..d9b2a77dabc9 100644 > --- a/drivers/misc/throttler/Makefile > +++ b/drivers/misc/throttler/Makefile > @@ -1 +1,2 @@ > obj-$(CONFIG_THROTTLER) += core.o > +obj-$(CONFIG_CROS_EC_THROTTLER) += cros_ec_throttler.o > diff --git a/drivers/misc/throttler/cros_ec_throttler.c b/drivers/misc/throttler/cros_ec_throttler.c > new file mode 100644 > index 000000000000..f1e9fc0a6284 > --- /dev/null > +++ b/drivers/misc/throttler/cros_ec_throttler.c > @@ -0,0 +1,109 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Driver for throttling triggered by events from the Chrome OS Embedded > + * Controller. > + * > + * Copyright (C) 2018 Google, Inc. > + */ > + > +#include <linux/kernel.h> > +#include <linux/mfd/cros_ec.h> > +#include <linux/module.h> > +#include <linux/notifier.h> > +#include <linux/of.h> > +#include <linux/of_platform.h> > +#include <linux/platform_device.h> > +#include <linux/throttler.h> > + > +#define nb_to_ce_thr(nb) container_of(nb, struct cros_ec_throttler, nb) > + > +struct cros_ec_throttler { > + struct cros_ec_device *ec; > + struct throttler *throttler; > + struct notifier_block nb; > +}; > + > +static int cros_ec_throttler_event(struct notifier_block *nb, > + unsigned long queued_during_suspend, void *_notify) > +{ > + struct cros_ec_throttler *ce_thr = nb_to_ce_thr(nb); > + u32 host_event; > + > + host_event = cros_ec_get_host_event(ce_thr->ec); > + if (host_event & EC_HOST_EVENT_MASK(EC_HOST_EVENT_THROTTLE_START)) { > + throttler_set_level(ce_thr->throttler, 1); > + > + return NOTIFY_OK; > + } else if (host_event & > + EC_HOST_EVENT_MASK(EC_HOST_EVENT_THROTTLE_STOP)) { > + throttler_set_level(ce_thr->throttler, 0); > + > + return NOTIFY_OK; > + } > + > + return NOTIFY_DONE; > +} > + > +static int cros_ec_throttler_probe(struct platform_device *pdev) > +{ > + struct cros_ec_throttler *ce_thr; > + struct device *dev = &pdev->dev; > + int ret; > + > + ce_thr = devm_kzalloc(dev, sizeof(*ce_thr), GFP_KERNEL); > + if (!ce_thr) > + return -ENOMEM; > + > + ce_thr->ec = dev_get_drvdata(pdev->dev.parent); > + > + /* > + * The core code uses the DT node of the throttler to identify its > + * throttling devices and rates. The CrOS EC throttler is a sub-device > + * of the CrOS EC MFD device and doesn't have its own device node. Use > + * the node of the MFD device instead. > + */ > + dev->of_node = dev->parent->of_node; It might be better to get the appropriate 'parent' (and of_node) pointer via the 'cros_ec_device' you retrieve above, since the parent might be different depending on my suggestions in patch 12...I think. Brian > + > + ce_thr->throttler = throttler_setup(dev); > + if (IS_ERR(ce_thr->throttler)) > + return PTR_ERR(ce_thr->throttler); > + > + dev_set_drvdata(dev, ce_thr); > + > + ce_thr->nb.notifier_call = cros_ec_throttler_event; > + ret = blocking_notifier_chain_register(&ce_thr->ec->event_notifier, > + &ce_thr->nb); > + if (ret < 0) { > + dev_err(dev, "failed to register notifier\n"); > + throttler_teardown(ce_thr->throttler); > + return ret; > + } > + > + return 0; > +} > + > +static int cros_ec_throttler_remove(struct platform_device *pdev) > +{ > + struct cros_ec_throttler *ce_thr = platform_get_drvdata(pdev); > + > + blocking_notifier_chain_unregister(&ce_thr->ec->event_notifier, > + &ce_thr->nb); > + > + throttler_teardown(ce_thr->throttler); > + > + return 0; > +} > + > +static struct platform_driver cros_ec_throttler_driver = { > + .driver = { > + .name = "cros-ec-throttler", > + }, > + .probe = cros_ec_throttler_probe, > + .remove = cros_ec_throttler_remove, > +}; > + > +module_platform_driver(cros_ec_throttler_driver); > + > +MODULE_LICENSE("GPL v2"); > +MODULE_AUTHOR("Matthias Kaehlcke <mka@chromium.org>"); > +MODULE_DESCRIPTION("Chrome OS EC Throttler"); > -- > 2.18.0.rc1.242.g61856ae69a-goog >
diff --git a/drivers/misc/throttler/Kconfig b/drivers/misc/throttler/Kconfig index 8b2e63b2ef48..ef984c96f67b 100644 --- a/drivers/misc/throttler/Kconfig +++ b/drivers/misc/throttler/Kconfig @@ -20,4 +20,14 @@ menuconfig THROTTLER_DEBUG Choose N unless you want to debug throttler drivers. +config CROS_EC_THROTTLER + tristate "Throttler event monitor for the Chrome OS Embedded Controller" + depends on MFD_CROS_EC + help + This driver adds support to throttle the system in reaction to + Chrome OS EC events. + + To compile this driver as a module, choose M here: the + module will be called cros_ec_throttler. + endif # THROTTLER diff --git a/drivers/misc/throttler/Makefile b/drivers/misc/throttler/Makefile index c8d920cee315..d9b2a77dabc9 100644 --- a/drivers/misc/throttler/Makefile +++ b/drivers/misc/throttler/Makefile @@ -1 +1,2 @@ obj-$(CONFIG_THROTTLER) += core.o +obj-$(CONFIG_CROS_EC_THROTTLER) += cros_ec_throttler.o diff --git a/drivers/misc/throttler/cros_ec_throttler.c b/drivers/misc/throttler/cros_ec_throttler.c new file mode 100644 index 000000000000..f1e9fc0a6284 --- /dev/null +++ b/drivers/misc/throttler/cros_ec_throttler.c @@ -0,0 +1,109 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Driver for throttling triggered by events from the Chrome OS Embedded + * Controller. + * + * Copyright (C) 2018 Google, Inc. + */ + +#include <linux/kernel.h> +#include <linux/mfd/cros_ec.h> +#include <linux/module.h> +#include <linux/notifier.h> +#include <linux/of.h> +#include <linux/of_platform.h> +#include <linux/platform_device.h> +#include <linux/throttler.h> + +#define nb_to_ce_thr(nb) container_of(nb, struct cros_ec_throttler, nb) + +struct cros_ec_throttler { + struct cros_ec_device *ec; + struct throttler *throttler; + struct notifier_block nb; +}; + +static int cros_ec_throttler_event(struct notifier_block *nb, + unsigned long queued_during_suspend, void *_notify) +{ + struct cros_ec_throttler *ce_thr = nb_to_ce_thr(nb); + u32 host_event; + + host_event = cros_ec_get_host_event(ce_thr->ec); + if (host_event & EC_HOST_EVENT_MASK(EC_HOST_EVENT_THROTTLE_START)) { + throttler_set_level(ce_thr->throttler, 1); + + return NOTIFY_OK; + } else if (host_event & + EC_HOST_EVENT_MASK(EC_HOST_EVENT_THROTTLE_STOP)) { + throttler_set_level(ce_thr->throttler, 0); + + return NOTIFY_OK; + } + + return NOTIFY_DONE; +} + +static int cros_ec_throttler_probe(struct platform_device *pdev) +{ + struct cros_ec_throttler *ce_thr; + struct device *dev = &pdev->dev; + int ret; + + ce_thr = devm_kzalloc(dev, sizeof(*ce_thr), GFP_KERNEL); + if (!ce_thr) + return -ENOMEM; + + ce_thr->ec = dev_get_drvdata(pdev->dev.parent); + + /* + * The core code uses the DT node of the throttler to identify its + * throttling devices and rates. The CrOS EC throttler is a sub-device + * of the CrOS EC MFD device and doesn't have its own device node. Use + * the node of the MFD device instead. + */ + dev->of_node = dev->parent->of_node; + + ce_thr->throttler = throttler_setup(dev); + if (IS_ERR(ce_thr->throttler)) + return PTR_ERR(ce_thr->throttler); + + dev_set_drvdata(dev, ce_thr); + + ce_thr->nb.notifier_call = cros_ec_throttler_event; + ret = blocking_notifier_chain_register(&ce_thr->ec->event_notifier, + &ce_thr->nb); + if (ret < 0) { + dev_err(dev, "failed to register notifier\n"); + throttler_teardown(ce_thr->throttler); + return ret; + } + + return 0; +} + +static int cros_ec_throttler_remove(struct platform_device *pdev) +{ + struct cros_ec_throttler *ce_thr = platform_get_drvdata(pdev); + + blocking_notifier_chain_unregister(&ce_thr->ec->event_notifier, + &ce_thr->nb); + + throttler_teardown(ce_thr->throttler); + + return 0; +} + +static struct platform_driver cros_ec_throttler_driver = { + .driver = { + .name = "cros-ec-throttler", + }, + .probe = cros_ec_throttler_probe, + .remove = cros_ec_throttler_remove, +}; + +module_platform_driver(cros_ec_throttler_driver); + +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Matthias Kaehlcke <mka@chromium.org>"); +MODULE_DESCRIPTION("Chrome OS EC Throttler");