Hi, On Tue, Mar 09, 2021 at 01:05:30AM +0100, Maximilian Luz wrote: > On newer Microsoft Surface models (specifically 7th-generation, i.e. > Surface Pro 7, Surface Book 3, Surface Laptop 3, and Surface Laptop Go), > battery and AC status/information is no longer handled via standard ACPI > devices, but instead directly via the Surface System Aggregator Module > (SSAM), i.e. the embedded controller on those devices. > > While on previous generation models, AC status is also handled via SSAM, > an ACPI shim was present to translate the standard ACPI AC interface to > SSAM requests. The SSAM interface itself, which is modeled closely after > the ACPI interface, has not changed. > > This commit introduces a new SSAM client device driver to support AC > status/information via the aforementioned interface on said Surface > models. > > Signed-off-by: Maximilian Luz <luzmaximilian@xxxxxxxxx> > --- > > Note: This patch depends on the > > platform/surface: Add Surface Aggregator device registry > > series. More specifically patch > > platform/surface: Set up Surface Aggregator device registry > > The full series has been merged into the for-next branch of the > platform-drivers-x86 tree [1]. The commit in question can be found at > [2]. > > [1]: https://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86.git/log/?h=for-next > [2]: https://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86.git/commit/?h=for-next&id=fc622b3d36e6d91330fb21506b9ad1e3206a4dde > > --- > MAINTAINERS | 1 + > drivers/power/supply/Kconfig | 16 ++ > drivers/power/supply/Makefile | 1 + > drivers/power/supply/surface_charger.c | 296 +++++++++++++++++++++++++ > 4 files changed, 314 insertions(+) > create mode 100644 drivers/power/supply/surface_charger.c > > diff --git a/MAINTAINERS b/MAINTAINERS > index f44521abe8bf..d6651ba93997 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -11867,6 +11867,7 @@ L: linux-pm@xxxxxxxxxxxxxxx > L: platform-driver-x86@xxxxxxxxxxxxxxx > S: Maintained > F: drivers/power/supply/surface_battery.c > +F: drivers/power/supply/surface_charger.c > > MICROSOFT SURFACE GPE LID SUPPORT DRIVER > M: Maximilian Luz <luzmaximilian@xxxxxxxxx> > diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig > index cebeff10d543..91f7cf425ac9 100644 > --- a/drivers/power/supply/Kconfig > +++ b/drivers/power/supply/Kconfig > @@ -817,4 +817,20 @@ config BATTERY_SURFACE > Microsoft Surface devices, i.e. Surface Pro 7, Surface Laptop 3, > Surface Book 3, and Surface Laptop Go. > > +config CHARGER_SURFACE > + tristate "AC driver for 7th-generation Microsoft Surface devices" > + depends on SURFACE_AGGREGATOR_REGISTRY > + help > + Driver for AC devices connected via/managed by the Surface System > + Aggregator Module (SSAM). > + > + This driver provides AC-information and -status support for Surface > + devices where said data is not exposed via the standard ACPI devices. > + On those models (7th-generation), AC-information is instead handled > + directly via a SSAM client device and this driver. > + > + Say M or Y here to include AC status support for 7th-generation > + Microsoft Surface devices, i.e. Surface Pro 7, Surface Laptop 3, > + Surface Book 3, and Surface Laptop Go. > + > endif # POWER_SUPPLY > diff --git a/drivers/power/supply/Makefile b/drivers/power/supply/Makefile > index 134041538d2c..a7309a3d1a47 100644 > --- a/drivers/power/supply/Makefile > +++ b/drivers/power/supply/Makefile > @@ -102,3 +102,4 @@ obj-$(CONFIG_CHARGER_WILCO) += wilco-charger.o > obj-$(CONFIG_RN5T618_POWER) += rn5t618_power.o > obj-$(CONFIG_BATTERY_ACER_A500) += acer_a500_battery.o > obj-$(CONFIG_BATTERY_SURFACE) += surface_battery.o > +obj-$(CONFIG_CHARGER_SURFACE) += surface_charger.o > diff --git a/drivers/power/supply/surface_charger.c b/drivers/power/supply/surface_charger.c > new file mode 100644 > index 000000000000..fe484523a2c2 > --- /dev/null > +++ b/drivers/power/supply/surface_charger.c > @@ -0,0 +1,296 @@ > +// SPDX-License-Identifier: GPL-2.0+ > +/* > + * AC driver for 7th-generation Microsoft Surface devices via Surface System > + * Aggregator Module (SSAM). > + * > + * Copyright (C) 2019-2021 Maximilian Luz <luzmaximilian@xxxxxxxxx> > + */ > + > +#include <asm/unaligned.h> > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/mutex.h> > +#include <linux/power_supply.h> > +#include <linux/types.h> > + > +#include <linux/surface_aggregator/device.h> > + > + > +/* -- SAM interface. -------------------------------------------------------- */ > + > +enum sam_event_cid_bat { > + SAM_EVENT_CID_BAT_ADP = 0x17, > +}; > + > +enum sam_battery_sta { > + SAM_BATTERY_STA_OK = 0x0f, > + SAM_BATTERY_STA_PRESENT = 0x10, > +}; > + > +/* Get battery status (_STA). */ > +SSAM_DEFINE_SYNC_REQUEST_CL_R(ssam_bat_get_sta, __le32, { > + .target_category = SSAM_SSH_TC_BAT, > + .command_id = 0x01, > +}); > + > +/* Get platform power source for battery (_PSR / DPTF PSRC). */ > +SSAM_DEFINE_SYNC_REQUEST_CL_R(ssam_bat_get_psrc, __le32, { > + .target_category = SSAM_SSH_TC_BAT, > + .command_id = 0x0d, > +}); > + > + > +/* -- Device structures. ---------------------------------------------------- */ > + > +struct spwr_psy_properties { > + const char *name; > + struct ssam_event_registry registry; > +}; > + > +struct spwr_ac_device { > + struct ssam_device *sdev; > + > + char name[32]; > + struct power_supply *psy; > + struct power_supply_desc psy_desc; > + > + struct ssam_event_notifier notif; > + > + struct mutex lock; /* Guards access to state below. */ > + > + __le32 state; > +}; > + > + > +/* -- State management. ----------------------------------------------------- */ > + > +static int spwr_ac_update_unlocked(struct spwr_ac_device *ac) > +{ > + u32 old = ac->state; > + int status; > + > + lockdep_assert_held(&ac->lock); > + > + status = ssam_retry(ssam_bat_get_psrc, ac->sdev, &ac->state); > + if (status < 0) > + return status; > + > + return old != ac->state; > +} > + > +static int spwr_ac_update(struct spwr_ac_device *ac) > +{ > + int status; > + > + mutex_lock(&ac->lock); > + status = spwr_ac_update_unlocked(ac); > + mutex_unlock(&ac->lock); > + > + return status; > +} > + > +static int spwr_ac_recheck(struct spwr_ac_device *ac) > +{ > + int status; > + > + status = spwr_ac_update(ac); > + if (status > 0) > + power_supply_changed(ac->psy); > + > + return status >= 0 ? 0 : status; > +} > + > +static u32 spwr_notify_ac(struct ssam_event_notifier *nf, const struct ssam_event *event) > +{ > + struct spwr_ac_device *ac; > + int status; > + > + ac = container_of(nf, struct spwr_ac_device, notif); > + > + dev_dbg(&ac->sdev->dev, "power event (cid = %#04x, iid = %#04x, tid = %#04x)\n", > + event->command_id, event->instance_id, event->target_id); > + > + /* > + * Allow events of all targets/instances here. Global adapter status > + * seems to be handled via target=1 and instance=1, but events are > + * reported on all targets/instances in use. > + * > + * While it should be enough to just listen on 1/1, listen everywhere to > + * make sure we don't miss anything. > + */ > + > + switch (event->command_id) { > + case SAM_EVENT_CID_BAT_ADP: > + status = spwr_ac_recheck(ac); > + return ssam_notifier_from_errno(status) | SSAM_NOTIF_HANDLED; > + > + default: > + return 0; > + } > +} > + > + > +/* -- Properties. ----------------------------------------------------------- */ > + > +static enum power_supply_property spwr_ac_props[] = { > + POWER_SUPPLY_PROP_ONLINE, > +}; > + > +static int spwr_ac_get_property(struct power_supply *psy, enum power_supply_property psp, > + union power_supply_propval *val) > +{ > + struct spwr_ac_device *ac = power_supply_get_drvdata(psy); > + int status; > + > + mutex_lock(&ac->lock); > + > + status = spwr_ac_update_unlocked(ac); > + if (status) > + goto out; > + > + switch (psp) { > + case POWER_SUPPLY_PROP_ONLINE: > + val->intval = !!le32_to_cpu(ac->state); > + break; > + > + default: > + status = -EINVAL; > + goto out; > + } > + > +out: > + mutex_unlock(&ac->lock); > + return status; > +} > + > + > +/* -- Device setup. --------------------------------------------------------- */ > + > +static void spwr_ac_init(struct spwr_ac_device *ac, struct ssam_device *sdev, > + struct ssam_event_registry registry, const char *name) > +{ > + mutex_init(&ac->lock); > + strncpy(ac->name, name, ARRAY_SIZE(ac->name) - 1); > + > + ac->sdev = sdev; > + > + ac->notif.base.priority = 1; > + ac->notif.base.fn = spwr_notify_ac; > + ac->notif.event.reg = registry; > + ac->notif.event.id.target_category = sdev->uid.category; > + ac->notif.event.id.instance = 0; > + ac->notif.event.mask = SSAM_EVENT_MASK_NONE; > + ac->notif.event.flags = SSAM_EVENT_SEQUENCED; > + > + ac->psy_desc.name = ac->name; > + ac->psy_desc.type = POWER_SUPPLY_TYPE_MAINS; > + ac->psy_desc.properties = spwr_ac_props; > + ac->psy_desc.num_properties = ARRAY_SIZE(spwr_ac_props); > + ac->psy_desc.get_property = spwr_ac_get_property; > +} > + > +static void spwr_ac_destroy(struct spwr_ac_device *ac) > +{ > + mutex_destroy(&ac->lock); same as battery driver - use devm_add_action_or_reset or just drop it. It's not very useful at the end of remove(). > +} static char *battery_supplied_to[] = { "BAT1", "BAT2", }; > +static int spwr_ac_register(struct spwr_ac_device *ac) > +{ > + struct power_supply_config psy_cfg = {}; > + __le32 sta; > + int status; > + > + /* Make sure the device is there and functioning properly. */ > + status = ssam_retry(ssam_bat_get_sta, ac->sdev, &sta); > + if (status) > + return status; > + > + if ((le32_to_cpu(sta) & SAM_BATTERY_STA_OK) != SAM_BATTERY_STA_OK) > + return -ENODEV; > + > + psy_cfg.drv_data = ac; psy_cfg.supplied_to = battery_supplied_to; psy_cfg.num_supplicants = 2; > + ac->psy = power_supply_register(&ac->sdev->dev, &ac->psy_desc, &psy_cfg); > + if (IS_ERR(ac->psy)) > + return PTR_ERR(ac->psy); > + > + status = ssam_notifier_register(ac->sdev->ctrl, &ac->notif); > + if (status) > + power_supply_unregister(ac->psy); > + > + return status; > +} > + > +static int spwr_ac_unregister(struct spwr_ac_device *ac) > +{ > + ssam_notifier_unregister(ac->sdev->ctrl, &ac->notif); > + power_supply_unregister(ac->psy); This driver can also use devm_power_supply_register :) > + return 0; > +} > + > + > +/* -- Driver setup. --------------------------------------------------------- */ > + > +static int __maybe_unused surface_ac_resume(struct device *dev) > +{ > + return spwr_ac_recheck(dev_get_drvdata(dev)); > +} > +SIMPLE_DEV_PM_OPS(surface_ac_pm_ops, NULL, surface_ac_resume); > + > +static int surface_ac_probe(struct ssam_device *sdev) > +{ > + const struct spwr_psy_properties *p; > + struct spwr_ac_device *ac; > + int status; > + > + p = ssam_device_get_match_data(sdev); > + if (!p) > + return -ENODEV; > + > + ac = devm_kzalloc(&sdev->dev, sizeof(*ac), GFP_KERNEL); > + if (!ac) > + return -ENOMEM; > + > + spwr_ac_init(ac, sdev, p->registry, p->name); > + ssam_device_set_drvdata(sdev, ac); > + > + status = spwr_ac_register(ac); > + if (status) > + spwr_ac_destroy(ac); > + > + return status; > +} > + > +static void surface_ac_remove(struct ssam_device *sdev) > +{ > + struct spwr_ac_device *ac = ssam_device_get_drvdata(sdev); > + > + spwr_ac_unregister(ac); > + spwr_ac_destroy(ac); > +} > + > +static const struct spwr_psy_properties spwr_psy_props_adp1 = { > + .name = "ADP1", > + .registry = SSAM_EVENT_REGISTRY_SAM, > +}; > + > +static const struct ssam_device_id surface_ac_match[] = { > + { SSAM_SDEV(BAT, 0x01, 0x01, 0x01), (unsigned long)&spwr_psy_props_adp1 }, > + { }, > +}; > +MODULE_DEVICE_TABLE(ssam, surface_ac_match); > + > +static struct ssam_device_driver surface_ac_driver = { > + .probe = surface_ac_probe, > + .remove = surface_ac_remove, > + .match_table = surface_ac_match, > + .driver = { > + .name = "surface_ac", > + .pm = &surface_ac_pm_ops, > + .probe_type = PROBE_PREFER_ASYNCHRONOUS, > + }, > +}; > +module_ssam_device_driver(surface_ac_driver); > + > +MODULE_AUTHOR("Maximilian Luz <luzmaximilian@xxxxxxxxx>"); > +MODULE_DESCRIPTION("AC driver for Surface System Aggregator Module"); > +MODULE_LICENSE("GPL"); Otherwise LGTM. Thanks, -- Sebastian
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