// SPDX-License-Identifier: GPL-2.0+
/*
* Driver for the Surface ACPI Notify (SAN) interface/shim.
*
* Translates communication from ACPI to Surface System Aggregator Module
* (SSAM/SAM) requests and back, specifically SAM-over-SSH. Translates SSAM
* events back to ACPI notifications. Allows handling of discrete GPU
* notifications sent from ACPI via the SAN interface by providing them to any
* registered external driver.
*
* Copyright (C) 2019-2022 Maximilian Luz <[email protected]>
*/
#include <linux/unaligned.h>
#include <linux/acpi.h>
#include <linux/delay.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/notifier.h>
#include <linux/platform_device.h>
#include <linux/rwsem.h>
#include <linux/surface_aggregator/controller.h>
#include <linux/surface_acpi_notify.h>
struct san_data {
struct device *dev;
struct ssam_controller *ctrl;
struct acpi_connection_info info;
struct ssam_event_notifier nf_bat;
struct ssam_event_notifier nf_tmp;
};
#define to_san_data(ptr, member) \
container_of(ptr, struct san_data, member)
static struct workqueue_struct *san_wq;
/* -- dGPU notifier interface. ---------------------------------------------- */
struct san_rqsg_if {
struct rw_semaphore lock;
struct device *dev;
struct blocking_notifier_head nh;
};
static struct san_rqsg_if san_rqsg_if = {
.lock = __RWSEM_INITIALIZER(san_rqsg_if.lock),
.dev = NULL,
.nh = BLOCKING_NOTIFIER_INIT(san_rqsg_if.nh),
};
static int san_set_rqsg_interface_device(struct device *dev)
{
int status = 0;
down_write(&san_rqsg_if.lock);
if (!san_rqsg_if.dev && dev)
san_rqsg_if.dev = dev;
else
status = -EBUSY;
up_write(&san_rqsg_if.lock);
return status;
}
/**
* san_client_link() - Link client as consumer to SAN device.
* @client: The client to link.
*
* Sets up a device link between the provided client device as consumer and
* the SAN device as provider. This function can be used to ensure that the
* SAN interface has been set up and will be set up for as long as the driver
* of the client device is bound. This guarantees that, during that time, all
* dGPU events will be received by any registered notifier.
*
* The link will be automatically removed once the client device's driver is
* unbound.
*
* Return: Returns zero on success, %-ENXIO if the SAN interface has not been
* set up yet, and %-ENOMEM if device link creation failed.
*/
int san_client_link(struct device *client)
{
const u32 flags = DL_FLAG_PM_RUNTIME | DL_FLAG_AUTOREMOVE_CONSUMER;
struct device_link *link;
down_read(&san_rqsg_if.lock);
if (!san_rqsg_if.dev) {
up_read(&san_rqsg_if.lock);
return -ENXIO;
}
link = device_link_add(client, san_rqsg_if.dev, flags);
if (!link) {
up_read(&san_rqsg_if.lock);
return -ENOMEM;
}
if (READ_ONCE(link->status) == DL_STATE_SUPPLIER_UNBIND) {
up_read(&san_rqsg_if.lock);
return -ENXIO;
}
up_read(&san_rqsg_if.lock);
return 0;
}
EXPORT_SYMBOL_GPL(san_client_link);
/**
* san_dgpu_notifier_register() - Register a SAN dGPU notifier.
* @nb: The notifier-block to register.
*
* Registers a SAN dGPU notifier, receiving any new SAN dGPU events sent from
* ACPI. The registered notifier will be called with &struct san_dgpu_event
* as notifier data and the command ID of that event as notifier action.
*/
int san_dgpu_notifier_register(struct notifier_block *nb)
{
return blocking_notifier_chain_register(&san_rqsg_if.nh, nb);
}
EXPORT_SYMBOL_GPL(san_dgpu_notifier_register);
/**
* san_dgpu_notifier_unregister() - Unregister a SAN dGPU notifier.
* @nb: The notifier-block to unregister.
*/
int san_dgpu_notifier_unregister(struct notifier_block *nb)
{
return blocking_notifier_chain_unregister(&san_rqsg_if.nh, nb);
}
EXPORT_SYMBOL_GPL(san_dgpu_notifier_unregister);
static int san_dgpu_notifier_call(struct san_dgpu_event *evt)
{
int ret;
ret = blocking_notifier_call_chain(&san_rqsg_if.nh, evt->command, evt);
return notifier_to_errno(ret);
}
/* -- ACPI _DSM event relay. ------------------------------------------------ */
#define SAN_DSM_REVISION 0
/* 93b666c5-70c6-469f-a215-3d487c91ab3c */
static const guid_t SAN_DSM_UUID =
GUID_INIT(0x93b666c5, 0x70c6, 0x469f, 0xa2, 0x15, 0x3d,
0x48, 0x7c, 0x91, 0xab, 0x3c);
enum san_dsm_event_fn {
SAN_DSM_EVENT_FN_BAT1_STAT = 0x03,
SAN_DSM_EVENT_FN_BAT1_INFO = 0x04,
SAN_DSM_EVENT_FN_ADP1_STAT = 0x05,
SAN_DSM_EVENT_FN_ADP1_INFO = 0x06,
SAN_DSM_EVENT_FN_BAT2_STAT = 0x07,
SAN_DSM_EVENT_FN_BAT2_INFO = 0x08,
SAN_DSM_EVENT_FN_THERMAL = 0x09,
SAN_DSM_EVENT_FN_DPTF = 0x0a,
};
enum sam_event_cid_bat {
SAM_EVENT_CID_BAT_BIX = 0x15,
SAM_EVENT_CID_BAT_BST = 0x16,
SAM_EVENT_CID_BAT_ADP = 0x17,
SAM_EVENT_CID_BAT_PROT = 0x18,
SAM_EVENT_CID_BAT_DPTF = 0x4f,
};
enum sam_event_cid_tmp {
SAM_EVENT_CID_TMP_TRIP = 0x0b,
};
struct san_event_work {
struct delayed_work work;
struct device *dev;
struct ssam_event event; /* must be last */
};
static int san_acpi_notify_event(struct device *dev, u64 func,
union acpi_object *param)
{
acpi_handle san = ACPI_HANDLE(dev);
union acpi_object *obj;
int status = 0;
if (!acpi_check_dsm(san, &SAN_DSM_UUID, SAN_DSM_REVISION, BIT_ULL(func)))
return 0;
dev_dbg(dev, "notify event %#04llx\n", func);
obj = acpi_evaluate_dsm_typed(san, &SAN_DSM_UUID, SAN_DSM_REVISION,
func, param, ACPI_TYPE_BUFFER);
if (!obj)
return -EFAULT;
if (obj->buffer.length != 1 || obj->buffer.pointer[0] != 0) {
dev_err(dev, "got unexpected result from _DSM\n");
status = -EPROTO;
}
ACPI_FREE(obj);
return status;
}
static int san_evt_bat_adp(struct device *dev, const struct ssam_event *event)
{
int status;
status = san_acpi_notify_event(dev, SAN_DSM_EVENT_FN_ADP1_STAT, NULL);
if (status)
return status;
/*
* Ensure that the battery states get updated correctly. When the
* battery is fully charged and an adapter is plugged in, it sometimes
* is not updated correctly, instead showing it as charging.
* Explicitly trigger battery updates to fix this.
*/
status = san_acpi_notify_event(dev, SAN_DSM_EVENT_FN_BAT1_STAT, NULL);
if (status)
return status;
return san_acpi_notify_event(dev, SAN_DSM_EVENT_FN_BAT2_STAT, NULL);
}
static int san_evt_bat_bix(struct device *dev, const struct ssam_event *event)
{
enum san_dsm_event_fn fn;
if (event->instance_id == 0x02)
fn = SAN_DSM_EVENT_FN_BAT2_INFO;
else
fn = SAN_DSM_EVENT_FN_BAT1_INFO;
return san_acpi_notify_event(dev, fn, NULL);
}
static int san_evt_bat_bst(struct device *dev, const struct ssam_event *event)
{
enum san_dsm_event_fn fn;
if (event->instance_id == 0x02)
fn = SAN_DSM_EVENT_FN_BAT2_STAT;
else
fn = SAN_DSM_EVENT_FN_BAT1_STAT;
return san_acpi_notify_event(dev, fn, NULL);
}
static int san_evt_bat_dptf(struct device *dev, const struct ssam_event *event)
{
union acpi_object payload;
/*
* The Surface ACPI expects a buffer and not a package. It specifically
* checks for ObjectType (Arg3) == 0x03. This will cause a warning in
* acpica/nsarguments.c, but that warning can be safely ignored.
*/
payload.type = ACPI_TYPE_BUFFER;
payload.buffer.length = event->length;
payload.buffer.pointer = (u8 *)&event->data[0];
return san_acpi_notify_event(dev, SAN_DSM_EVENT_FN_DPTF, &payload);
}
static unsigned long san_evt_bat_delay(u8 cid)
{
switch (cid) {
case SAM_EVENT_CID_BAT_ADP:
/*
* Wait for battery state to update before signaling adapter
* change.
*/
return msecs_to_jiffies(5000);
case SAM_EVENT_CID_BAT_BST:
/* Ensure we do not miss anything important due to caching. */
return msecs_to_jiffies(2000);
default:
return 0;
}
}
static bool san_evt_bat(const struct ssam_event *event, struct device *dev)
{
int status;
switch (event->command_id) {
case SAM_EVENT_CID_BAT_BIX:
status = san_evt_bat_bix(dev, event);
break;
case SAM_EVENT_CID_BAT_BST:
status = san_evt_bat_bst(dev, event);
break;
case SAM_EVENT_CID_BAT_ADP:
status = san_evt_bat_adp(dev, event);
break;
case SAM_EVENT_CID_BAT_PROT:
/*
* TODO: Implement support for battery protection status change
* event.
*/
return true;
case SAM_EVENT_CID_BAT_DPTF:
status = san_evt_bat_dptf(dev, event);
break;
default:
return false;
}
if (status) {
dev_err(dev, "error handling power event (cid = %#04x)\n",
event->command_id);
}
return true;
}
static void san_evt_bat_workfn(struct work_struct *work)
{
struct san_event_work *ev;
ev = container_of(work, struct san_event_work, work.work);
san_evt_bat(&ev->event, ev->dev);
kfree(ev);
}
static u32 san_evt_bat_nf(struct ssam_event_notifier *nf,
const struct ssam_event *event)
{
struct san_data *d = to_san_data(nf, nf_bat);
struct san_event_work *work;
unsigned long delay = san_evt_bat_delay(event->command_id);
if (delay == 0)
return san_evt_bat(event, d->dev) ? SSAM_NOTIF_HANDLED : 0;
work = kzalloc(sizeof(*work) + event->length, GFP_KERNEL);
if (!work)
return ssam_notifier_from_errno(-ENOMEM);
INIT_DELAYED_WORK(&work->work, san_evt_bat_workfn);
work->dev = d->dev;
work->event = *event;
memcpy(work->event.data, event->data, event->length);
queue_delayed_work(san_wq, &work->work, delay);
return SSAM_NOTIF_HANDLED;
}
static int san_evt_tmp_trip(struct device *dev, const struct ssam_event *event)
{
union acpi_object param;
/*
* The Surface ACPI expects an integer and not a package. This will
* cause a warning in acpica/nsarguments.c, but that warning can be
* safely ignored.
*/
param.type = ACPI_TYPE_INTEGER;
param.integer.value = event->instance_id;
return san_acpi_notify_event(dev, SAN_DSM_EVENT_FN_THERMAL, ¶m);
}
static bool san_evt_tmp(const struct ssam_event *event, struct device *dev)
{
int status;
switch (event->command_id) {
case SAM_EVENT_CID_TMP_TRIP:
status = san_evt_tmp_trip(dev, event);
break;
default:
return false;
}
if (status) {
dev_err(dev, "error handling thermal event (cid = %#04x)\n",
event->command_id);
}
return true;
}
static u32 san_evt_tmp_nf(struct ssam_event_notifier *nf,
const struct ssam_event *event)
{
struct san_data *d = to_san_data(nf, nf_tmp);
return san_evt_tmp(event, d->dev) ? SSAM_NOTIF_HANDLED : 0;
}
/* -- ACPI GSB OperationRegion handler -------------------------------------- */
struct gsb_data_in {
u8 cv;
} __packed;
struct gsb_data_rqsx {
u8 cv; /* Command value (san_gsb_request_cv). */
u8 tc; /* Target category. */
u8 tid; /* Target ID. */
u8 iid; /* Instance ID. */
u8 snc; /* Expect-response-flag. */
u8 cid; /* Command ID. */
u16 cdl; /* Payload length. */
u8 pld[]; /* Payload. */
} __packed;
struct gsb_data_etwl {
u8 cv; /* Command value (should be 0x02). */
u8 etw3; /* Unknown. */
u8 etw4; /* Unknown. */
u8 msg[]; /* Error message (ASCIIZ). */
} __packed;
struct gsb_data_out {
u8 status; /* _SSH communication status. */
u8 len; /* _SSH payload length. */
u8 pld[]; /* _SSH payload. */
} __packed;
union gsb_buffer_data {
struct gsb_data_in in; /* Common input. */
struct gsb_data_rqsx rqsx; /* RQSX input. */
struct gsb_data_etwl etwl; /* ETWL input. */
struct gsb_data_out out; /* Output. */
};
struct gsb_buffer {
u8 status; /* GSB AttribRawProcess status. */
u8 len; /* GSB AttribRawProcess length. */
union gsb_buffer_data data;
} __packed;
#define SAN_GSB_MAX_RQSX_PAYLOAD (U8_MAX - 2 - sizeof(struct gsb_data_rqsx))
#define SAN_GSB_MAX_RESPONSE (U8_MAX - 2 - sizeof(struct gsb_data_out))
#define SAN_GSB_COMMAND 0
enum san_gsb_request_cv {
SAN_GSB_REQUEST_CV_RQST = 0x01,
SAN_GSB_REQUEST_CV_ETWL = 0x02,
SAN_GSB_REQUEST_CV_RQSG = 0x03,
};
#define SAN_REQUEST_NUM_TRIES 5
static acpi_status san_etwl(struct san_data *d, struct gsb_buffer *b)
{
struct gsb_data_etwl *etwl = &b->data.etwl;
if (b->len < sizeof(struct gsb_data_etwl)) {
dev_err(d->dev, "invalid ETWL package (len = %d)\n", b->len);
return AE_OK;
}
dev_err(d->dev, "ETWL(%#04x, %#04x): %.*s\n", etwl->etw3, etwl->etw4,
(unsigned int)(b->len - sizeof(struct gsb_data_etwl)),
(char *)etwl->msg);
/* Indicate success. */
b->status = 0x00;
b->len = 0x00;
return AE_OK;
}
static
struct gsb_data_rqsx *san_validate_rqsx(struct device *dev, const char *type,
struct gsb_buffer *b)
{
struct gsb_data_rqsx *rqsx = &b->data.rqsx;
if (b->len < sizeof(struct gsb_data_rqsx)) {
dev_err(dev, "invalid %s package (len = %d)\n", type, b->len);
return NULL;
}
if (get_unaligned(&rqsx->cdl) != b->len - sizeof(struct gsb_data_rqsx)) {
dev_err(dev, "bogus %s package (len = %d, cdl = %d)\n",
type, b->len, get_unaligned(&rqsx->cdl));
return NULL;
}
if (get_unaligned(&rqsx->cdl) > SAN_GSB_MAX_RQSX_PAYLOAD) {
dev_err(dev, "payload for %s package too large (cdl = %d)\n",
type, get_unaligned(&rqsx->cdl));
return NULL;
}
return rqsx;
}
static void gsb_rqsx_response_error(struct gsb_buffer *gsb, int status)
{
gsb->status = 0x00;
gsb->len = 0x02;
gsb->data.out.status = (u8)(-status);
gsb->data.out.len = 0x00;
}
static void gsb_rqsx_response_success(struct gsb_buffer *gsb, u8 *ptr, size_t len)
{
gsb->status = 0x00;
gsb->len = len + 2;
gsb->data.out.status = 0x00;
gsb->data.out.len = len;
if (len)
memcpy(&gsb->data.out.pld[0], ptr, len);
}
static acpi_status san_rqst_fixup_suspended(struct san_data *d,
struct ssam_request *rqst,
struct gsb_buffer *gsb)
{
if (rqst->target_category == SSAM_SSH_TC_BAS && rqst->command_id == 0x0D) {
u8 base_state = 1;
/* Base state quirk:
* The base state may be queried from ACPI when the EC is still
* suspended. In this case it will return '-EPERM'. This query
* will only be triggered from the ACPI lid GPE interrupt, thus
* we are either in laptop or studio mode (base status 0x01 or
* 0x02). Furthermore, we will only get here if the device (and
* EC) have been suspended.
*
* We now assume that the device is in laptop mode (0x01). This
* has the drawback that it will wake the device when unfolding
* it in studio mode, but it also allows us to avoid actively
* waiting for the EC to wake up, which may incur a notable
* delay.
*/
dev_dbg(d->dev, "rqst: fixup: base-state quirk\n");
gsb_rqsx_response_success(gsb, &base_state, sizeof(base_state));
return AE_OK;
}
gsb_rqsx_response_error(gsb, -ENXIO);
return AE_OK;
}
static acpi_status san_rqst(struct san_data *d, struct gsb_buffer *buffer)
{
u8 rspbuf[SAN_GSB_MAX_RESPONSE];
struct gsb_data_rqsx *gsb_rqst;
struct ssam_request rqst;
struct ssam_response rsp;
int status = 0;
gsb_rqst = san_validate_rqsx(d->dev, "RQST", buffer);
if (!gsb_rqst)
return AE_OK;
rqst.target_category = gsb_rqst->tc;
rqst.target_id = gsb_rqst->tid;
rqst.command_id = gsb_rqst->cid;
rqst.instance_id = gsb_rqst->iid;
rqst.flags = gsb_rqst->snc ? SSAM_REQUEST_HAS_RESPONSE : 0;
rqst.length = get_unaligned(&gsb_rqst->cdl);
rqst.payload = &gsb_rqst->pld[0];
rsp.capacity = ARRAY_SIZE(rspbuf);
rsp.length = 0;
rsp.pointer = &rspbuf[0];
/* Handle suspended device. */
if (d->dev->power.is_suspended) {
dev_warn(d->dev, "rqst: device is suspended, not executing\n");
return san_rqst_fixup_suspended(d, &rqst, buffer);
}
status = __ssam_retry(ssam_request_do_sync_onstack, SAN_REQUEST_NUM_TRIES,
d->ctrl, &rqst, &rsp, SAN_GSB_MAX_RQSX_PAYLOAD);
if (!status) {
gsb_rqsx_response_success(buffer, rsp.pointer, rsp.length);
} else {
dev_err(d->dev, "rqst: failed with error %d\n", status);
gsb_rqsx_response_error(buffer, status);
}
return AE_OK;
}
static acpi_status san_rqsg(struct san_data *d, struct gsb_buffer *buffer)
{
struct gsb_data_rqsx *gsb_rqsg;
struct san_dgpu_event evt;
int status;
gsb_rqsg = san_validate_rqsx(d->dev, "RQSG", buffer);
if (!gsb_rqsg)
return AE_OK;
evt.category = gsb_rqsg->tc;
evt.target = gsb_rqsg->tid;
evt.command = gsb_rqsg->cid;
evt.instance = gsb_rqsg->iid;
evt.length = get_unaligned(&gsb_rqsg->cdl);
evt.payload = &gsb_rqsg->pld[0];
status = san_dgpu_notifier_call(&evt);
if (!status) {
gsb_rqsx_response_success(buffer, NULL, 0);
} else {
dev_err(d->dev, "rqsg: failed with error %d\n", status);
gsb_rqsx_response_error(buffer, status);
}
return AE_OK;
}
static acpi_status san_opreg_handler(u32 function, acpi_physical_address command,
u32 bits, u64 *value64, void *opreg_context,
void *region_context)
{
struct san_data *d = to_san_data(opreg_context, info);
struct gsb_buffer *buffer = (struct gsb_buffer *)value64;
int accessor_type = (function & 0xFFFF0000) >> 16;
if (command != SAN_GSB_COMMAND) {
dev_warn(d->dev, "unsupported command: %#04llx\n", command);
return AE_OK;
}
if (accessor_type != ACPI_GSB_ACCESS_ATTRIB_RAW_PROCESS) {
dev_err(d->dev, "invalid access type: %#04x\n", accessor_type);
return AE_OK;
}
/* Buffer must have at least contain the command-value. */
if (buffer->len == 0) {
dev_err(d->dev, "request-package too small\n");
return AE_OK;
}
switch (buffer->data.in.cv) {
case SAN_GSB_REQUEST_CV_RQST:
return san_rqst(d, buffer);
case SAN_GSB_REQUEST_CV_ETWL:
return san_etwl(d, buffer);
case SAN_GSB_REQUEST_CV_RQSG:
return san_rqsg(d, buffer);
default:
dev_warn(d->dev, "unsupported SAN0 request (cv: %#04x)\n",
buffer->data.in.cv);
return AE_OK;
}
}
/* -- Driver setup. --------------------------------------------------------- */
static int san_events_register(struct platform_device *pdev)
{
struct san_data *d = platform_get_drvdata(pdev);
int status;
d->nf_bat.base.priority = 1;
d->nf_bat.base.fn = san_evt_bat_nf;
d->nf_bat.event.reg = SSAM_EVENT_REGISTRY_SAM;
d->nf_bat.event.id.target_category = SSAM_SSH_TC_BAT;
d->nf_bat.event.id.instance = 0;
d->nf_bat.event.mask = SSAM_EVENT_MASK_TARGET;
d->nf_bat.event.flags = SSAM_EVENT_SEQUENCED;
d->nf_tmp.base.priority = 1;
d->nf_tmp.base.fn = san_evt_tmp_nf;
d->nf_tmp.event.reg = SSAM_EVENT_REGISTRY_SAM;
d->nf_tmp.event.id.target_category = SSAM_SSH_TC_TMP;
d->nf_tmp.event.id.instance = 0;
d->nf_tmp.event.mask = SSAM_EVENT_MASK_TARGET;
d->nf_tmp.event.flags = SSAM_EVENT_SEQUENCED;
status = ssam_notifier_register(d->ctrl, &d->nf_bat);
if (status)
return status;
status = ssam_notifier_register(d->ctrl, &d->nf_tmp);
if (status)
ssam_notifier_unregister(d->ctrl, &d->nf_bat);
return status;
}
static void san_events_unregister(struct platform_device *pdev)
{
struct san_data *d = platform_get_drvdata(pdev);
ssam_notifier_unregister(d->ctrl, &d->nf_bat);
ssam_notifier_unregister(d->ctrl, &d->nf_tmp);
}
#define san_consumer_printk(level, dev, handle, fmt, ...) \
do { \
char *path = "<error getting consumer path>"; \
struct acpi_buffer buffer = { \
.length = ACPI_ALLOCATE_BUFFER, \
.pointer = NULL, \
}; \
\
if (ACPI_SUCCESS(acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer))) \
path = buffer.pointer; \
\
dev_##level(dev, "[%s]: " fmt, path, ##__VA_ARGS__); \
kfree(buffer.pointer); \
} while (0)
#define san_consumer_dbg(dev, handle, fmt, ...) \
san_consumer_printk(dbg, dev, handle, fmt, ##__VA_ARGS__)
#define san_consumer_warn(dev, handle, fmt, ...) \
san_consumer_printk(warn, dev, handle, fmt, ##__VA_ARGS__)
static acpi_status san_consumer_setup(acpi_handle handle, u32 lvl,
void *context, void **rv)
{
const u32 flags = DL_FLAG_PM_RUNTIME | DL_FLAG_AUTOREMOVE_SUPPLIER;
struct platform_device *pdev = context;
struct acpi_device *adev;
struct device_link *link;
if (!acpi_device_dep(handle, ACPI_HANDLE(&pdev->dev)))
return AE_OK;
/* Ignore ACPI devices that are not present. */
adev = acpi_fetch_acpi_dev(handle);
if (!adev)
return AE_OK;
san_consumer_dbg(&pdev->dev, handle, "creating device link\n");
/* Try to set up device links, ignore but log errors. */
link = device_link_add(&adev->dev, &pdev->dev, flags);
if (!link) {
san_consumer_warn(&pdev->dev, handle, "failed to create device link\n");
return AE_OK;
}
return AE_OK;
}
static int san_consumer_links_setup(struct platform_device *pdev)
{
acpi_status status;
status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
ACPI_UINT32_MAX, san_consumer_setup, NULL,
pdev, NULL);
return status ? -EFAULT : 0;
}
static int san_probe(struct platform_device *pdev)
{
struct acpi_device *san = ACPI_COMPANION(&pdev->dev);
struct ssam_controller *ctrl;
struct san_data *data;
acpi_status astatus;
int status;
ctrl = ssam_client_bind(&pdev->dev);
if (IS_ERR(ctrl))
return PTR_ERR(ctrl) == -ENODEV ? -EPROBE_DEFER : PTR_ERR(ctrl);
status = san_consumer_links_setup(pdev);
if (status)
return status;
data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;
data->dev = &pdev->dev;
data->ctrl = ctrl;
platform_set_drvdata(pdev, data);
astatus = acpi_install_address_space_handler(san->handle,
ACPI_ADR_SPACE_GSBUS,
&san_opreg_handler, NULL,
&data->info);
if (ACPI_FAILURE(astatus))
return -ENXIO;
status = san_events_register(pdev);
if (status)
goto err_enable_events;
status = san_set_rqsg_interface_device(&pdev->dev);
if (status)
goto err_install_dev;
acpi_dev_clear_dependencies(san);
return 0;
err_install_dev:
san_events_unregister(pdev);
err_enable_events:
acpi_remove_address_space_handler(san, ACPI_ADR_SPACE_GSBUS,
&san_opreg_handler);
return status;
}
static void san_remove(struct platform_device *pdev)
{
acpi_handle san = ACPI_HANDLE(&pdev->dev);
san_set_rqsg_interface_device(NULL);
acpi_remove_address_space_handler(san, ACPI_ADR_SPACE_GSBUS,
&san_opreg_handler);
san_events_unregister(pdev);
/*
* We have unregistered our event sources. Now we need to ensure that
* all delayed works they may have spawned are run to completion.
*/
flush_workqueue(san_wq);
}
static const struct acpi_device_id san_match[] = {
{ "MSHW0091" },
{ },
};
MODULE_DEVICE_TABLE(acpi, san_match);
static struct platform_driver surface_acpi_notify = {
.probe = san_probe,
.remove_new = san_remove,
.driver = {
.name = "surface_acpi_notify",
.acpi_match_table = san_match,
.probe_type = PROBE_PREFER_ASYNCHRONOUS,
},
};
static int __init san_init(void)
{
int ret;
san_wq = alloc_workqueue("san_wq", 0, 0);
if (!san_wq)
return -ENOMEM;
ret = platform_driver_register(&surface_acpi_notify);
if (ret)
destroy_workqueue(san_wq);
return ret;
}
module_init(san_init);
static void __exit san_exit(void)
{
platform_driver_unregister(&surface_acpi_notify);
destroy_workqueue(san_wq);
}
module_exit(san_exit);
MODULE_AUTHOR("Maximilian Luz <[email protected]>");
MODULE_DESCRIPTION("Surface ACPI Notify driver for Surface System Aggregator Module");
MODULE_LICENSE("GPL");
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