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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 *  ec.c - ACPI Embedded Controller Driver (v3)4 *5 *  Copyright (C) 2001-2015 Intel Corporation6 *    Author: 2014, 2015 Lv Zheng <lv.zheng@intel.com>7 *            2006, 2007 Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>8 *            2006       Denis Sadykov <denis.m.sadykov@intel.com>9 *            2004       Luming Yu <luming.yu@intel.com>10 *            2001, 2002 Andy Grover <andrew.grover@intel.com>11 *            2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>12 *  Copyright (C) 2008      Alexey Starikovskiy <astarikovskiy@suse.de>13 */14 15/* Uncomment next line to get verbose printout */16/* #define DEBUG */17#define pr_fmt(fmt) "ACPI: EC: " fmt18 19#include <linux/kernel.h>20#include <linux/module.h>21#include <linux/init.h>22#include <linux/types.h>23#include <linux/delay.h>24#include <linux/interrupt.h>25#include <linux/list.h>26#include <linux/spinlock.h>27#include <linux/slab.h>28#include <linux/suspend.h>29#include <linux/acpi.h>30#include <linux/dmi.h>31#include <asm/io.h>32 33#include "internal.h"34 35#define ACPI_EC_CLASS			"embedded_controller"36#define ACPI_EC_DEVICE_NAME		"Embedded Controller"37 38/* EC status register */39#define ACPI_EC_FLAG_OBF	0x01	/* Output buffer full */40#define ACPI_EC_FLAG_IBF	0x02	/* Input buffer full */41#define ACPI_EC_FLAG_CMD	0x08	/* Input buffer contains a command */42#define ACPI_EC_FLAG_BURST	0x10	/* burst mode */43#define ACPI_EC_FLAG_SCI	0x20	/* EC-SCI occurred */44 45/*46 * The SCI_EVT clearing timing is not defined by the ACPI specification.47 * This leads to lots of practical timing issues for the host EC driver.48 * The following variations are defined (from the target EC firmware's49 * perspective):50 * STATUS: After indicating SCI_EVT edge triggered IRQ to the host, the51 *         target can clear SCI_EVT at any time so long as the host can see52 *         the indication by reading the status register (EC_SC). So the53 *         host should re-check SCI_EVT after the first time the SCI_EVT54 *         indication is seen, which is the same time the query request55 *         (QR_EC) is written to the command register (EC_CMD). SCI_EVT set56 *         at any later time could indicate another event. Normally such57 *         kind of EC firmware has implemented an event queue and will58 *         return 0x00 to indicate "no outstanding event".59 * QUERY: After seeing the query request (QR_EC) written to the command60 *        register (EC_CMD) by the host and having prepared the responding61 *        event value in the data register (EC_DATA), the target can safely62 *        clear SCI_EVT because the target can confirm that the current63 *        event is being handled by the host. The host then should check64 *        SCI_EVT right after reading the event response from the data65 *        register (EC_DATA).66 * EVENT: After seeing the event response read from the data register67 *        (EC_DATA) by the host, the target can clear SCI_EVT. As the68 *        target requires time to notice the change in the data register69 *        (EC_DATA), the host may be required to wait additional guarding70 *        time before checking the SCI_EVT again. Such guarding may not be71 *        necessary if the host is notified via another IRQ.72 */73#define ACPI_EC_EVT_TIMING_STATUS	0x0074#define ACPI_EC_EVT_TIMING_QUERY	0x0175#define ACPI_EC_EVT_TIMING_EVENT	0x0276 77/* EC commands */78enum ec_command {79	ACPI_EC_COMMAND_READ = 0x80,80	ACPI_EC_COMMAND_WRITE = 0x81,81	ACPI_EC_BURST_ENABLE = 0x82,82	ACPI_EC_BURST_DISABLE = 0x83,83	ACPI_EC_COMMAND_QUERY = 0x84,84};85 86#define ACPI_EC_DELAY		500	/* Wait 500ms max. during EC ops */87#define ACPI_EC_UDELAY_GLK	1000	/* Wait 1ms max. to get global lock */88#define ACPI_EC_UDELAY_POLL	550	/* Wait 1ms for EC transaction polling */89#define ACPI_EC_CLEAR_MAX	100	/* Maximum number of events to query90					 * when trying to clear the EC */91#define ACPI_EC_MAX_QUERIES	16	/* Maximum number of parallel queries */92 93enum {94	EC_FLAGS_QUERY_ENABLED,		/* Query is enabled */95	EC_FLAGS_EVENT_HANDLER_INSTALLED,	/* Event handler installed */96	EC_FLAGS_EC_HANDLER_INSTALLED,	/* OpReg handler installed */97	EC_FLAGS_EC_REG_CALLED,		/* OpReg ACPI _REG method called */98	EC_FLAGS_QUERY_METHODS_INSTALLED, /* _Qxx handlers installed */99	EC_FLAGS_STARTED,		/* Driver is started */100	EC_FLAGS_STOPPED,		/* Driver is stopped */101	EC_FLAGS_EVENTS_MASKED,		/* Events masked */102};103 104#define ACPI_EC_COMMAND_POLL		0x01 /* Available for command byte */105#define ACPI_EC_COMMAND_COMPLETE	0x02 /* Completed last byte */106 107/* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */108static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;109module_param(ec_delay, uint, 0644);110MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");111 112static unsigned int ec_max_queries __read_mostly = ACPI_EC_MAX_QUERIES;113module_param(ec_max_queries, uint, 0644);114MODULE_PARM_DESC(ec_max_queries, "Maximum parallel _Qxx evaluations");115 116static bool ec_busy_polling __read_mostly;117module_param(ec_busy_polling, bool, 0644);118MODULE_PARM_DESC(ec_busy_polling, "Use busy polling to advance EC transaction");119 120static unsigned int ec_polling_guard __read_mostly = ACPI_EC_UDELAY_POLL;121module_param(ec_polling_guard, uint, 0644);122MODULE_PARM_DESC(ec_polling_guard, "Guard time(us) between EC accesses in polling modes");123 124static unsigned int ec_event_clearing __read_mostly = ACPI_EC_EVT_TIMING_QUERY;125 126/*127 * If the number of false interrupts per one transaction exceeds128 * this threshold, will think there is a GPE storm happened and129 * will disable the GPE for normal transaction.130 */131static unsigned int ec_storm_threshold  __read_mostly = 8;132module_param(ec_storm_threshold, uint, 0644);133MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");134 135static bool ec_freeze_events __read_mostly;136module_param(ec_freeze_events, bool, 0644);137MODULE_PARM_DESC(ec_freeze_events, "Disabling event handling during suspend/resume");138 139static bool ec_no_wakeup __read_mostly;140module_param(ec_no_wakeup, bool, 0644);141MODULE_PARM_DESC(ec_no_wakeup, "Do not wake up from suspend-to-idle");142 143struct acpi_ec_query_handler {144	struct list_head node;145	acpi_ec_query_func func;146	acpi_handle handle;147	void *data;148	u8 query_bit;149	struct kref kref;150};151 152struct transaction {153	const u8 *wdata;154	u8 *rdata;155	unsigned short irq_count;156	u8 command;157	u8 wi;158	u8 ri;159	u8 wlen;160	u8 rlen;161	u8 flags;162};163 164struct acpi_ec_query {165	struct transaction transaction;166	struct work_struct work;167	struct acpi_ec_query_handler *handler;168	struct acpi_ec *ec;169};170 171static int acpi_ec_submit_query(struct acpi_ec *ec);172static void advance_transaction(struct acpi_ec *ec, bool interrupt);173static void acpi_ec_event_handler(struct work_struct *work);174 175struct acpi_ec *first_ec;176EXPORT_SYMBOL(first_ec);177 178static struct acpi_ec *boot_ec;179static bool boot_ec_is_ecdt;180static struct workqueue_struct *ec_wq;181static struct workqueue_struct *ec_query_wq;182 183static int EC_FLAGS_CORRECT_ECDT; /* Needs ECDT port address correction */184static int EC_FLAGS_TRUST_DSDT_GPE; /* Needs DSDT GPE as correction setting */185static int EC_FLAGS_CLEAR_ON_RESUME; /* Needs acpi_ec_clear() on boot/resume */186 187/* --------------------------------------------------------------------------188 *                           Logging/Debugging189 * -------------------------------------------------------------------------- */190 191/*192 * Splitters used by the developers to track the boundary of the EC193 * handling processes.194 */195#ifdef DEBUG196#define EC_DBG_SEP	" "197#define EC_DBG_DRV	"+++++"198#define EC_DBG_STM	"====="199#define EC_DBG_REQ	"*****"200#define EC_DBG_EVT	"#####"201#else202#define EC_DBG_SEP	""203#define EC_DBG_DRV204#define EC_DBG_STM205#define EC_DBG_REQ206#define EC_DBG_EVT207#endif208 209#define ec_log_raw(fmt, ...) \210	pr_info(fmt "\n", ##__VA_ARGS__)211#define ec_dbg_raw(fmt, ...) \212	pr_debug(fmt "\n", ##__VA_ARGS__)213#define ec_log(filter, fmt, ...) \214	ec_log_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)215#define ec_dbg(filter, fmt, ...) \216	ec_dbg_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)217 218#define ec_log_drv(fmt, ...) \219	ec_log(EC_DBG_DRV, fmt, ##__VA_ARGS__)220#define ec_dbg_drv(fmt, ...) \221	ec_dbg(EC_DBG_DRV, fmt, ##__VA_ARGS__)222#define ec_dbg_stm(fmt, ...) \223	ec_dbg(EC_DBG_STM, fmt, ##__VA_ARGS__)224#define ec_dbg_req(fmt, ...) \225	ec_dbg(EC_DBG_REQ, fmt, ##__VA_ARGS__)226#define ec_dbg_evt(fmt, ...) \227	ec_dbg(EC_DBG_EVT, fmt, ##__VA_ARGS__)228#define ec_dbg_ref(ec, fmt, ...) \229	ec_dbg_raw("%lu: " fmt, ec->reference_count, ## __VA_ARGS__)230 231/* --------------------------------------------------------------------------232 *                           Device Flags233 * -------------------------------------------------------------------------- */234 235static bool acpi_ec_started(struct acpi_ec *ec)236{237	return test_bit(EC_FLAGS_STARTED, &ec->flags) &&238	       !test_bit(EC_FLAGS_STOPPED, &ec->flags);239}240 241static bool acpi_ec_event_enabled(struct acpi_ec *ec)242{243	/*244	 * There is an OSPM early stage logic. During the early stages245	 * (boot/resume), OSPMs shouldn't enable the event handling, only246	 * the EC transactions are allowed to be performed.247	 */248	if (!test_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))249		return false;250	/*251	 * However, disabling the event handling is experimental for late252	 * stage (suspend), and is controlled by the boot parameter of253	 * "ec_freeze_events":254	 * 1. true:  The EC event handling is disabled before entering255	 *           the noirq stage.256	 * 2. false: The EC event handling is automatically disabled as257	 *           soon as the EC driver is stopped.258	 */259	if (ec_freeze_events)260		return acpi_ec_started(ec);261	else262		return test_bit(EC_FLAGS_STARTED, &ec->flags);263}264 265static bool acpi_ec_flushed(struct acpi_ec *ec)266{267	return ec->reference_count == 1;268}269 270/* --------------------------------------------------------------------------271 *                           EC Registers272 * -------------------------------------------------------------------------- */273 274static inline u8 acpi_ec_read_status(struct acpi_ec *ec)275{276	u8 x = inb(ec->command_addr);277 278	ec_dbg_raw("EC_SC(R) = 0x%2.2x "279		   "SCI_EVT=%d BURST=%d CMD=%d IBF=%d OBF=%d",280		   x,281		   !!(x & ACPI_EC_FLAG_SCI),282		   !!(x & ACPI_EC_FLAG_BURST),283		   !!(x & ACPI_EC_FLAG_CMD),284		   !!(x & ACPI_EC_FLAG_IBF),285		   !!(x & ACPI_EC_FLAG_OBF));286	return x;287}288 289static inline u8 acpi_ec_read_data(struct acpi_ec *ec)290{291	u8 x = inb(ec->data_addr);292 293	ec->timestamp = jiffies;294	ec_dbg_raw("EC_DATA(R) = 0x%2.2x", x);295	return x;296}297 298static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)299{300	ec_dbg_raw("EC_SC(W) = 0x%2.2x", command);301	outb(command, ec->command_addr);302	ec->timestamp = jiffies;303}304 305static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)306{307	ec_dbg_raw("EC_DATA(W) = 0x%2.2x", data);308	outb(data, ec->data_addr);309	ec->timestamp = jiffies;310}311 312#if defined(DEBUG) || defined(CONFIG_DYNAMIC_DEBUG)313static const char *acpi_ec_cmd_string(u8 cmd)314{315	switch (cmd) {316	case 0x80:317		return "RD_EC";318	case 0x81:319		return "WR_EC";320	case 0x82:321		return "BE_EC";322	case 0x83:323		return "BD_EC";324	case 0x84:325		return "QR_EC";326	}327	return "UNKNOWN";328}329#else330#define acpi_ec_cmd_string(cmd)		"UNDEF"331#endif332 333/* --------------------------------------------------------------------------334 *                           GPE Registers335 * -------------------------------------------------------------------------- */336 337static inline bool acpi_ec_gpe_status_set(struct acpi_ec *ec)338{339	acpi_event_status gpe_status = 0;340 341	(void)acpi_get_gpe_status(NULL, ec->gpe, &gpe_status);342	return !!(gpe_status & ACPI_EVENT_FLAG_STATUS_SET);343}344 345static inline void acpi_ec_enable_gpe(struct acpi_ec *ec, bool open)346{347	if (open)348		acpi_enable_gpe(NULL, ec->gpe);349	else {350		BUG_ON(ec->reference_count < 1);351		acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);352	}353	if (acpi_ec_gpe_status_set(ec)) {354		/*355		 * On some platforms, EN=1 writes cannot trigger GPE. So356		 * software need to manually trigger a pseudo GPE event on357		 * EN=1 writes.358		 */359		ec_dbg_raw("Polling quirk");360		advance_transaction(ec, false);361	}362}363 364static inline void acpi_ec_disable_gpe(struct acpi_ec *ec, bool close)365{366	if (close)367		acpi_disable_gpe(NULL, ec->gpe);368	else {369		BUG_ON(ec->reference_count < 1);370		acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);371	}372}373 374/* --------------------------------------------------------------------------375 *                           Transaction Management376 * -------------------------------------------------------------------------- */377 378static void acpi_ec_submit_request(struct acpi_ec *ec)379{380	ec->reference_count++;381	if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags) &&382	    ec->gpe >= 0 && ec->reference_count == 1)383		acpi_ec_enable_gpe(ec, true);384}385 386static void acpi_ec_complete_request(struct acpi_ec *ec)387{388	bool flushed = false;389 390	ec->reference_count--;391	if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags) &&392	    ec->gpe >= 0 && ec->reference_count == 0)393		acpi_ec_disable_gpe(ec, true);394	flushed = acpi_ec_flushed(ec);395	if (flushed)396		wake_up(&ec->wait);397}398 399static void acpi_ec_mask_events(struct acpi_ec *ec)400{401	if (!test_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags)) {402		if (ec->gpe >= 0)403			acpi_ec_disable_gpe(ec, false);404		else405			disable_irq_nosync(ec->irq);406 407		ec_dbg_drv("Polling enabled");408		set_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags);409	}410}411 412static void acpi_ec_unmask_events(struct acpi_ec *ec)413{414	if (test_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags)) {415		clear_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags);416		if (ec->gpe >= 0)417			acpi_ec_enable_gpe(ec, false);418		else419			enable_irq(ec->irq);420 421		ec_dbg_drv("Polling disabled");422	}423}424 425/*426 * acpi_ec_submit_flushable_request() - Increase the reference count unless427 *                                      the flush operation is not in428 *                                      progress429 * @ec: the EC device430 *431 * This function must be used before taking a new action that should hold432 * the reference count.  If this function returns false, then the action433 * must be discarded or it will prevent the flush operation from being434 * completed.435 */436static bool acpi_ec_submit_flushable_request(struct acpi_ec *ec)437{438	if (!acpi_ec_started(ec))439		return false;440	acpi_ec_submit_request(ec);441	return true;442}443 444static void acpi_ec_submit_event(struct acpi_ec *ec)445{446	/*447	 * It is safe to mask the events here, because acpi_ec_close_event()448	 * will run at least once after this.449	 */450	acpi_ec_mask_events(ec);451	if (!acpi_ec_event_enabled(ec))452		return;453 454	if (ec->event_state != EC_EVENT_READY)455		return;456 457	ec_dbg_evt("Command(%s) submitted/blocked",458		   acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));459 460	ec->event_state = EC_EVENT_IN_PROGRESS;461	/*462	 * If events_to_process is greater than 0 at this point, the while ()463	 * loop in acpi_ec_event_handler() is still running and incrementing464	 * events_to_process will cause it to invoke acpi_ec_submit_query() once465	 * more, so it is not necessary to queue up the event work to start the466	 * same loop again.467	 */468	if (ec->events_to_process++ > 0)469		return;470 471	ec->events_in_progress++;472	queue_work(ec_wq, &ec->work);473}474 475static void acpi_ec_complete_event(struct acpi_ec *ec)476{477	if (ec->event_state == EC_EVENT_IN_PROGRESS)478		ec->event_state = EC_EVENT_COMPLETE;479}480 481static void acpi_ec_close_event(struct acpi_ec *ec)482{483	if (ec->event_state != EC_EVENT_READY)484		ec_dbg_evt("Command(%s) unblocked",485			   acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));486 487	ec->event_state = EC_EVENT_READY;488	acpi_ec_unmask_events(ec);489}490 491static inline void __acpi_ec_enable_event(struct acpi_ec *ec)492{493	if (!test_and_set_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))494		ec_log_drv("event unblocked");495	/*496	 * Unconditionally invoke this once after enabling the event497	 * handling mechanism to detect the pending events.498	 */499	advance_transaction(ec, false);500}501 502static inline void __acpi_ec_disable_event(struct acpi_ec *ec)503{504	if (test_and_clear_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))505		ec_log_drv("event blocked");506}507 508/*509 * Process _Q events that might have accumulated in the EC.510 * Run with locked ec mutex.511 */512static void acpi_ec_clear(struct acpi_ec *ec)513{514	int i;515 516	for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) {517		if (acpi_ec_submit_query(ec))518			break;519	}520	if (unlikely(i == ACPI_EC_CLEAR_MAX))521		pr_warn("Warning: Maximum of %d stale EC events cleared\n", i);522	else523		pr_info("%d stale EC events cleared\n", i);524}525 526static void acpi_ec_enable_event(struct acpi_ec *ec)527{528	unsigned long flags;529 530	spin_lock_irqsave(&ec->lock, flags);531	if (acpi_ec_started(ec))532		__acpi_ec_enable_event(ec);533	spin_unlock_irqrestore(&ec->lock, flags);534 535	/* Drain additional events if hardware requires that */536	if (EC_FLAGS_CLEAR_ON_RESUME)537		acpi_ec_clear(ec);538}539 540#ifdef CONFIG_PM_SLEEP541static void __acpi_ec_flush_work(void)542{543	flush_workqueue(ec_wq); /* flush ec->work */544	flush_workqueue(ec_query_wq); /* flush queries */545}546 547static void acpi_ec_disable_event(struct acpi_ec *ec)548{549	unsigned long flags;550 551	spin_lock_irqsave(&ec->lock, flags);552	__acpi_ec_disable_event(ec);553	spin_unlock_irqrestore(&ec->lock, flags);554 555	/*556	 * When ec_freeze_events is true, we need to flush events in557	 * the proper position before entering the noirq stage.558	 */559	__acpi_ec_flush_work();560}561 562void acpi_ec_flush_work(void)563{564	/* Without ec_wq there is nothing to flush. */565	if (!ec_wq)566		return;567 568	__acpi_ec_flush_work();569}570#endif /* CONFIG_PM_SLEEP */571 572static bool acpi_ec_guard_event(struct acpi_ec *ec)573{574	unsigned long flags;575	bool guarded;576 577	spin_lock_irqsave(&ec->lock, flags);578	/*579	 * If firmware SCI_EVT clearing timing is "event", we actually580	 * don't know when the SCI_EVT will be cleared by firmware after581	 * evaluating _Qxx, so we need to re-check SCI_EVT after waiting an582	 * acceptable period.583	 *584	 * The guarding period is applicable if the event state is not585	 * EC_EVENT_READY, but otherwise if the current transaction is of the586	 * ACPI_EC_COMMAND_QUERY type, the guarding should have elapsed already587	 * and it should not be applied to let the transaction transition into588	 * the ACPI_EC_COMMAND_POLL state immediately.589	 */590	guarded = ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&591		ec->event_state != EC_EVENT_READY &&592		(!ec->curr || ec->curr->command != ACPI_EC_COMMAND_QUERY);593	spin_unlock_irqrestore(&ec->lock, flags);594	return guarded;595}596 597static int ec_transaction_polled(struct acpi_ec *ec)598{599	unsigned long flags;600	int ret = 0;601 602	spin_lock_irqsave(&ec->lock, flags);603	if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_POLL))604		ret = 1;605	spin_unlock_irqrestore(&ec->lock, flags);606	return ret;607}608 609static int ec_transaction_completed(struct acpi_ec *ec)610{611	unsigned long flags;612	int ret = 0;613 614	spin_lock_irqsave(&ec->lock, flags);615	if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE))616		ret = 1;617	spin_unlock_irqrestore(&ec->lock, flags);618	return ret;619}620 621static inline void ec_transaction_transition(struct acpi_ec *ec, unsigned long flag)622{623	ec->curr->flags |= flag;624 625	if (ec->curr->command != ACPI_EC_COMMAND_QUERY)626		return;627 628	switch (ec_event_clearing) {629	case ACPI_EC_EVT_TIMING_STATUS:630		if (flag == ACPI_EC_COMMAND_POLL)631			acpi_ec_close_event(ec);632 633		return;634 635	case ACPI_EC_EVT_TIMING_QUERY:636		if (flag == ACPI_EC_COMMAND_COMPLETE)637			acpi_ec_close_event(ec);638 639		return;640 641	case ACPI_EC_EVT_TIMING_EVENT:642		if (flag == ACPI_EC_COMMAND_COMPLETE)643			acpi_ec_complete_event(ec);644	}645}646 647static void acpi_ec_spurious_interrupt(struct acpi_ec *ec, struct transaction *t)648{649	if (t->irq_count < ec_storm_threshold)650		++t->irq_count;651 652	/* Trigger if the threshold is 0 too. */653	if (t->irq_count == ec_storm_threshold)654		acpi_ec_mask_events(ec);655}656 657static void advance_transaction(struct acpi_ec *ec, bool interrupt)658{659	struct transaction *t = ec->curr;660	bool wakeup = false;661	u8 status;662 663	ec_dbg_stm("%s (%d)", interrupt ? "IRQ" : "TASK", smp_processor_id());664 665	status = acpi_ec_read_status(ec);666 667	/*668	 * Another IRQ or a guarded polling mode advancement is detected,669	 * the next QR_EC submission is then allowed.670	 */671	if (!t || !(t->flags & ACPI_EC_COMMAND_POLL)) {672		if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&673		    ec->event_state == EC_EVENT_COMPLETE)674			acpi_ec_close_event(ec);675 676		if (!t)677			goto out;678	}679 680	if (t->flags & ACPI_EC_COMMAND_POLL) {681		if (t->wlen > t->wi) {682			if (!(status & ACPI_EC_FLAG_IBF))683				acpi_ec_write_data(ec, t->wdata[t->wi++]);684			else if (interrupt && !(status & ACPI_EC_FLAG_SCI))685				acpi_ec_spurious_interrupt(ec, t);686		} else if (t->rlen > t->ri) {687			if (status & ACPI_EC_FLAG_OBF) {688				t->rdata[t->ri++] = acpi_ec_read_data(ec);689				if (t->rlen == t->ri) {690					ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);691					wakeup = true;692					if (t->command == ACPI_EC_COMMAND_QUERY)693						ec_dbg_evt("Command(%s) completed by hardware",694							   acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));695				}696			} else if (interrupt && !(status & ACPI_EC_FLAG_SCI)) {697				acpi_ec_spurious_interrupt(ec, t);698			}699		} else if (t->wlen == t->wi && !(status & ACPI_EC_FLAG_IBF)) {700			ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);701			wakeup = true;702		}703	} else if (!(status & ACPI_EC_FLAG_IBF)) {704		acpi_ec_write_cmd(ec, t->command);705		ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL);706	}707 708out:709	if (status & ACPI_EC_FLAG_SCI)710		acpi_ec_submit_event(ec);711 712	if (wakeup && interrupt)713		wake_up(&ec->wait);714}715 716static void start_transaction(struct acpi_ec *ec)717{718	ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;719	ec->curr->flags = 0;720}721 722static int ec_guard(struct acpi_ec *ec)723{724	unsigned long guard = usecs_to_jiffies(ec->polling_guard);725	unsigned long timeout = ec->timestamp + guard;726 727	/* Ensure guarding period before polling EC status */728	do {729		if (ec->busy_polling) {730			/* Perform busy polling */731			if (ec_transaction_completed(ec))732				return 0;733			udelay(jiffies_to_usecs(guard));734		} else {735			/*736			 * Perform wait polling737			 * 1. Wait the transaction to be completed by the738			 *    GPE handler after the transaction enters739			 *    ACPI_EC_COMMAND_POLL state.740			 * 2. A special guarding logic is also required741			 *    for event clearing mode "event" before the742			 *    transaction enters ACPI_EC_COMMAND_POLL743			 *    state.744			 */745			if (!ec_transaction_polled(ec) &&746			    !acpi_ec_guard_event(ec))747				break;748			if (wait_event_timeout(ec->wait,749					       ec_transaction_completed(ec),750					       guard))751				return 0;752		}753	} while (time_before(jiffies, timeout));754	return -ETIME;755}756 757static int ec_poll(struct acpi_ec *ec)758{759	unsigned long flags;760	int repeat = 5; /* number of command restarts */761 762	while (repeat--) {763		unsigned long delay = jiffies +764			msecs_to_jiffies(ec_delay);765		do {766			if (!ec_guard(ec))767				return 0;768			spin_lock_irqsave(&ec->lock, flags);769			advance_transaction(ec, false);770			spin_unlock_irqrestore(&ec->lock, flags);771		} while (time_before(jiffies, delay));772		pr_debug("controller reset, restart transaction\n");773		spin_lock_irqsave(&ec->lock, flags);774		start_transaction(ec);775		spin_unlock_irqrestore(&ec->lock, flags);776	}777	return -ETIME;778}779 780static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,781					struct transaction *t)782{783	unsigned long tmp;784	int ret = 0;785 786	if (t->rdata)787		memset(t->rdata, 0, t->rlen);788 789	/* start transaction */790	spin_lock_irqsave(&ec->lock, tmp);791	/* Enable GPE for command processing (IBF=0/OBF=1) */792	if (!acpi_ec_submit_flushable_request(ec)) {793		ret = -EINVAL;794		goto unlock;795	}796	ec_dbg_ref(ec, "Increase command");797	/* following two actions should be kept atomic */798	ec->curr = t;799	ec_dbg_req("Command(%s) started", acpi_ec_cmd_string(t->command));800	start_transaction(ec);801	spin_unlock_irqrestore(&ec->lock, tmp);802 803	ret = ec_poll(ec);804 805	spin_lock_irqsave(&ec->lock, tmp);806	if (t->irq_count == ec_storm_threshold)807		acpi_ec_unmask_events(ec);808	ec_dbg_req("Command(%s) stopped", acpi_ec_cmd_string(t->command));809	ec->curr = NULL;810	/* Disable GPE for command processing (IBF=0/OBF=1) */811	acpi_ec_complete_request(ec);812	ec_dbg_ref(ec, "Decrease command");813unlock:814	spin_unlock_irqrestore(&ec->lock, tmp);815	return ret;816}817 818static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)819{820	int status;821	u32 glk;822 823	if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))824		return -EINVAL;825 826	mutex_lock(&ec->mutex);827	if (ec->global_lock) {828		status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);829		if (ACPI_FAILURE(status)) {830			status = -ENODEV;831			goto unlock;832		}833	}834 835	status = acpi_ec_transaction_unlocked(ec, t);836 837	if (ec->global_lock)838		acpi_release_global_lock(glk);839unlock:840	mutex_unlock(&ec->mutex);841	return status;842}843 844static int acpi_ec_burst_enable(struct acpi_ec *ec)845{846	u8 d;847	struct transaction t = {.command = ACPI_EC_BURST_ENABLE,848				.wdata = NULL, .rdata = &d,849				.wlen = 0, .rlen = 1};850 851	return acpi_ec_transaction_unlocked(ec, &t);852}853 854static int acpi_ec_burst_disable(struct acpi_ec *ec)855{856	struct transaction t = {.command = ACPI_EC_BURST_DISABLE,857				.wdata = NULL, .rdata = NULL,858				.wlen = 0, .rlen = 0};859 860	return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?861				acpi_ec_transaction_unlocked(ec, &t) : 0;862}863 864static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 *data)865{866	int result;867	u8 d;868	struct transaction t = {.command = ACPI_EC_COMMAND_READ,869				.wdata = &address, .rdata = &d,870				.wlen = 1, .rlen = 1};871 872	result = acpi_ec_transaction(ec, &t);873	*data = d;874	return result;875}876 877static int acpi_ec_read_unlocked(struct acpi_ec *ec, u8 address, u8 *data)878{879	int result;880	u8 d;881	struct transaction t = {.command = ACPI_EC_COMMAND_READ,882				.wdata = &address, .rdata = &d,883				.wlen = 1, .rlen = 1};884 885	result = acpi_ec_transaction_unlocked(ec, &t);886	*data = d;887	return result;888}889 890static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)891{892	u8 wdata[2] = { address, data };893	struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,894				.wdata = wdata, .rdata = NULL,895				.wlen = 2, .rlen = 0};896 897	return acpi_ec_transaction(ec, &t);898}899 900static int acpi_ec_write_unlocked(struct acpi_ec *ec, u8 address, u8 data)901{902	u8 wdata[2] = { address, data };903	struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,904				.wdata = wdata, .rdata = NULL,905				.wlen = 2, .rlen = 0};906 907	return acpi_ec_transaction_unlocked(ec, &t);908}909 910int ec_read(u8 addr, u8 *val)911{912	int err;913	u8 temp_data;914 915	if (!first_ec)916		return -ENODEV;917 918	err = acpi_ec_read(first_ec, addr, &temp_data);919 920	if (!err) {921		*val = temp_data;922		return 0;923	}924	return err;925}926EXPORT_SYMBOL(ec_read);927 928int ec_write(u8 addr, u8 val)929{930	if (!first_ec)931		return -ENODEV;932 933	return acpi_ec_write(first_ec, addr, val);934}935EXPORT_SYMBOL(ec_write);936 937int ec_transaction(u8 command,938		   const u8 *wdata, unsigned wdata_len,939		   u8 *rdata, unsigned rdata_len)940{941	struct transaction t = {.command = command,942				.wdata = wdata, .rdata = rdata,943				.wlen = wdata_len, .rlen = rdata_len};944 945	if (!first_ec)946		return -ENODEV;947 948	return acpi_ec_transaction(first_ec, &t);949}950EXPORT_SYMBOL(ec_transaction);951 952/* Get the handle to the EC device */953acpi_handle ec_get_handle(void)954{955	if (!first_ec)956		return NULL;957	return first_ec->handle;958}959EXPORT_SYMBOL(ec_get_handle);960 961static void acpi_ec_start(struct acpi_ec *ec, bool resuming)962{963	unsigned long flags;964 965	spin_lock_irqsave(&ec->lock, flags);966	if (!test_and_set_bit(EC_FLAGS_STARTED, &ec->flags)) {967		ec_dbg_drv("Starting EC");968		/* Enable GPE for event processing (SCI_EVT=1) */969		if (!resuming) {970			acpi_ec_submit_request(ec);971			ec_dbg_ref(ec, "Increase driver");972		}973		ec_log_drv("EC started");974	}975	spin_unlock_irqrestore(&ec->lock, flags);976}977 978static bool acpi_ec_stopped(struct acpi_ec *ec)979{980	unsigned long flags;981	bool flushed;982 983	spin_lock_irqsave(&ec->lock, flags);984	flushed = acpi_ec_flushed(ec);985	spin_unlock_irqrestore(&ec->lock, flags);986	return flushed;987}988 989static void acpi_ec_stop(struct acpi_ec *ec, bool suspending)990{991	unsigned long flags;992 993	spin_lock_irqsave(&ec->lock, flags);994	if (acpi_ec_started(ec)) {995		ec_dbg_drv("Stopping EC");996		set_bit(EC_FLAGS_STOPPED, &ec->flags);997		spin_unlock_irqrestore(&ec->lock, flags);998		wait_event(ec->wait, acpi_ec_stopped(ec));999		spin_lock_irqsave(&ec->lock, flags);1000		/* Disable GPE for event processing (SCI_EVT=1) */1001		if (!suspending) {1002			acpi_ec_complete_request(ec);1003			ec_dbg_ref(ec, "Decrease driver");1004		} else if (!ec_freeze_events)1005			__acpi_ec_disable_event(ec);1006		clear_bit(EC_FLAGS_STARTED, &ec->flags);1007		clear_bit(EC_FLAGS_STOPPED, &ec->flags);1008		ec_log_drv("EC stopped");1009	}1010	spin_unlock_irqrestore(&ec->lock, flags);1011}1012 1013static void acpi_ec_enter_noirq(struct acpi_ec *ec)1014{1015	unsigned long flags;1016 1017	spin_lock_irqsave(&ec->lock, flags);1018	ec->busy_polling = true;1019	ec->polling_guard = 0;1020	ec_log_drv("interrupt blocked");1021	spin_unlock_irqrestore(&ec->lock, flags);1022}1023 1024static void acpi_ec_leave_noirq(struct acpi_ec *ec)1025{1026	unsigned long flags;1027 1028	spin_lock_irqsave(&ec->lock, flags);1029	ec->busy_polling = ec_busy_polling;1030	ec->polling_guard = ec_polling_guard;1031	ec_log_drv("interrupt unblocked");1032	spin_unlock_irqrestore(&ec->lock, flags);1033}1034 1035void acpi_ec_block_transactions(void)1036{1037	struct acpi_ec *ec = first_ec;1038 1039	if (!ec)1040		return;1041 1042	mutex_lock(&ec->mutex);1043	/* Prevent transactions from being carried out */1044	acpi_ec_stop(ec, true);1045	mutex_unlock(&ec->mutex);1046}1047 1048void acpi_ec_unblock_transactions(void)1049{1050	/*1051	 * Allow transactions to happen again (this function is called from1052	 * atomic context during wakeup, so we don't need to acquire the mutex).1053	 */1054	if (first_ec)1055		acpi_ec_start(first_ec, true);1056}1057 1058/* --------------------------------------------------------------------------1059                                Event Management1060   -------------------------------------------------------------------------- */1061static struct acpi_ec_query_handler *1062acpi_ec_get_query_handler_by_value(struct acpi_ec *ec, u8 value)1063{1064	struct acpi_ec_query_handler *handler;1065 1066	mutex_lock(&ec->mutex);1067	list_for_each_entry(handler, &ec->list, node) {1068		if (value == handler->query_bit) {1069			kref_get(&handler->kref);1070			mutex_unlock(&ec->mutex);1071			return handler;1072		}1073	}1074	mutex_unlock(&ec->mutex);1075	return NULL;1076}1077 1078static void acpi_ec_query_handler_release(struct kref *kref)1079{1080	struct acpi_ec_query_handler *handler =1081		container_of(kref, struct acpi_ec_query_handler, kref);1082 1083	kfree(handler);1084}1085 1086static void acpi_ec_put_query_handler(struct acpi_ec_query_handler *handler)1087{1088	kref_put(&handler->kref, acpi_ec_query_handler_release);1089}1090 1091int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,1092			      acpi_handle handle, acpi_ec_query_func func,1093			      void *data)1094{1095	struct acpi_ec_query_handler *handler;1096 1097	if (!handle && !func)1098		return -EINVAL;1099 1100	handler = kzalloc(sizeof(*handler), GFP_KERNEL);1101	if (!handler)1102		return -ENOMEM;1103 1104	handler->query_bit = query_bit;1105	handler->handle = handle;1106	handler->func = func;1107	handler->data = data;1108	mutex_lock(&ec->mutex);1109	kref_init(&handler->kref);1110	list_add(&handler->node, &ec->list);1111	mutex_unlock(&ec->mutex);1112 1113	return 0;1114}1115EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);1116 1117static void acpi_ec_remove_query_handlers(struct acpi_ec *ec,1118					  bool remove_all, u8 query_bit)1119{1120	struct acpi_ec_query_handler *handler, *tmp;1121	LIST_HEAD(free_list);1122 1123	mutex_lock(&ec->mutex);1124	list_for_each_entry_safe(handler, tmp, &ec->list, node) {1125		/*1126		 * When remove_all is false, only remove custom query handlers1127		 * which have handler->func set. This is done to preserve query1128		 * handlers discovered thru ACPI, as they should continue handling1129		 * EC queries.1130		 */1131		if (remove_all || (handler->func && handler->query_bit == query_bit)) {1132			list_del_init(&handler->node);1133			list_add(&handler->node, &free_list);1134 1135		}1136	}1137	mutex_unlock(&ec->mutex);1138	list_for_each_entry_safe(handler, tmp, &free_list, node)1139		acpi_ec_put_query_handler(handler);1140}1141 1142void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)1143{1144	acpi_ec_remove_query_handlers(ec, false, query_bit);1145	flush_workqueue(ec_query_wq);1146}1147EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);1148 1149static void acpi_ec_event_processor(struct work_struct *work)1150{1151	struct acpi_ec_query *q = container_of(work, struct acpi_ec_query, work);1152	struct acpi_ec_query_handler *handler = q->handler;1153	struct acpi_ec *ec = q->ec;1154 1155	ec_dbg_evt("Query(0x%02x) started", handler->query_bit);1156 1157	if (handler->func)1158		handler->func(handler->data);1159	else if (handler->handle)1160		acpi_evaluate_object(handler->handle, NULL, NULL, NULL);1161 1162	ec_dbg_evt("Query(0x%02x) stopped", handler->query_bit);1163 1164	spin_lock_irq(&ec->lock);1165	ec->queries_in_progress--;1166	spin_unlock_irq(&ec->lock);1167 1168	acpi_ec_put_query_handler(handler);1169	kfree(q);1170}1171 1172static struct acpi_ec_query *acpi_ec_create_query(struct acpi_ec *ec, u8 *pval)1173{1174	struct acpi_ec_query *q;1175	struct transaction *t;1176 1177	q = kzalloc(sizeof (struct acpi_ec_query), GFP_KERNEL);1178	if (!q)1179		return NULL;1180 1181	INIT_WORK(&q->work, acpi_ec_event_processor);1182	t = &q->transaction;1183	t->command = ACPI_EC_COMMAND_QUERY;1184	t->rdata = pval;1185	t->rlen = 1;1186	q->ec = ec;1187	return q;1188}1189 1190static int acpi_ec_submit_query(struct acpi_ec *ec)1191{1192	struct acpi_ec_query *q;1193	u8 value = 0;1194	int result;1195 1196	q = acpi_ec_create_query(ec, &value);1197	if (!q)1198		return -ENOMEM;1199 1200	/*1201	 * Query the EC to find out which _Qxx method we need to evaluate.1202	 * Note that successful completion of the query causes the ACPI_EC_SCI1203	 * bit to be cleared (and thus clearing the interrupt source).1204	 */1205	result = acpi_ec_transaction(ec, &q->transaction);1206	if (result)1207		goto err_exit;1208 1209	if (!value) {1210		result = -ENODATA;1211		goto err_exit;1212	}1213 1214	q->handler = acpi_ec_get_query_handler_by_value(ec, value);1215	if (!q->handler) {1216		result = -ENODATA;1217		goto err_exit;1218	}1219 1220	/*1221	 * It is reported that _Qxx are evaluated in a parallel way on Windows:1222	 * https://bugzilla.kernel.org/show_bug.cgi?id=944111223	 *1224	 * Put this log entry before queue_work() to make it appear in the log1225	 * before any other messages emitted during workqueue handling.1226	 */1227	ec_dbg_evt("Query(0x%02x) scheduled", value);1228 1229	spin_lock_irq(&ec->lock);1230 1231	ec->queries_in_progress++;1232	queue_work(ec_query_wq, &q->work);1233 1234	spin_unlock_irq(&ec->lock);1235 1236	return 0;1237 1238err_exit:1239	kfree(q);1240 1241	return result;1242}1243 1244static void acpi_ec_event_handler(struct work_struct *work)1245{1246	struct acpi_ec *ec = container_of(work, struct acpi_ec, work);1247 1248	ec_dbg_evt("Event started");1249 1250	spin_lock_irq(&ec->lock);1251 1252	while (ec->events_to_process) {1253		spin_unlock_irq(&ec->lock);1254 1255		acpi_ec_submit_query(ec);1256 1257		spin_lock_irq(&ec->lock);1258 1259		ec->events_to_process--;1260	}1261 1262	/*1263	 * Before exit, make sure that the it will be possible to queue up the1264	 * event handling work again regardless of whether or not the query1265	 * queued up above is processed successfully.1266	 */1267	if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT) {1268		bool guard_timeout;1269 1270		acpi_ec_complete_event(ec);1271 1272		ec_dbg_evt("Event stopped");1273 1274		spin_unlock_irq(&ec->lock);1275 1276		guard_timeout = !!ec_guard(ec);1277 1278		spin_lock_irq(&ec->lock);1279 1280		/* Take care of SCI_EVT unless someone else is doing that. */1281		if (guard_timeout && !ec->curr)1282			advance_transaction(ec, false);1283	} else {1284		acpi_ec_close_event(ec);1285 1286		ec_dbg_evt("Event stopped");1287	}1288 1289	ec->events_in_progress--;1290 1291	spin_unlock_irq(&ec->lock);1292}1293 1294static void clear_gpe_and_advance_transaction(struct acpi_ec *ec, bool interrupt)1295{1296	/*1297	 * Clear GPE_STS upfront to allow subsequent hardware GPE_STS 0->11298	 * changes to always trigger a GPE interrupt.1299	 *1300	 * GPE STS is a W1C register, which means:1301	 *1302	 * 1. Software can clear it without worrying about clearing the other1303	 *    GPEs' STS bits when the hardware sets them in parallel.1304	 *1305	 * 2. As long as software can ensure only clearing it when it is set,1306	 *    hardware won't set it in parallel.1307	 */1308	if (ec->gpe >= 0 && acpi_ec_gpe_status_set(ec))1309		acpi_clear_gpe(NULL, ec->gpe);1310 1311	advance_transaction(ec, true);1312}1313 1314static void acpi_ec_handle_interrupt(struct acpi_ec *ec)1315{1316	unsigned long flags;1317 1318	spin_lock_irqsave(&ec->lock, flags);1319 1320	clear_gpe_and_advance_transaction(ec, true);1321 1322	spin_unlock_irqrestore(&ec->lock, flags);1323}1324 1325static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,1326			       u32 gpe_number, void *data)1327{1328	acpi_ec_handle_interrupt(data);1329	return ACPI_INTERRUPT_HANDLED;1330}1331 1332static irqreturn_t acpi_ec_irq_handler(int irq, void *data)1333{1334	acpi_ec_handle_interrupt(data);1335	return IRQ_HANDLED;1336}1337 1338/* --------------------------------------------------------------------------1339 *                           Address Space Management1340 * -------------------------------------------------------------------------- */1341 1342static acpi_status1343acpi_ec_space_handler(u32 function, acpi_physical_address address,1344		      u32 bits, u64 *value64,1345		      void *handler_context, void *region_context)1346{1347	struct acpi_ec *ec = handler_context;1348	int result = 0, i, bytes = bits / 8;1349	u8 *value = (u8 *)value64;1350	u32 glk;1351 1352	if ((address > 0xFF) || !value || !handler_context)1353		return AE_BAD_PARAMETER;1354 1355	if (function != ACPI_READ && function != ACPI_WRITE)1356		return AE_BAD_PARAMETER;1357 1358	mutex_lock(&ec->mutex);1359 1360	if (ec->global_lock) {1361		acpi_status status;1362 1363		status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);1364		if (ACPI_FAILURE(status)) {1365			result = -ENODEV;1366			goto unlock;1367		}1368	}1369 1370	if (ec->busy_polling || bits > 8)1371		acpi_ec_burst_enable(ec);1372 1373	for (i = 0; i < bytes; ++i, ++address, ++value) {1374		result = (function == ACPI_READ) ?1375			acpi_ec_read_unlocked(ec, address, value) :1376			acpi_ec_write_unlocked(ec, address, *value);1377		if (result < 0)1378			break;1379	}1380 1381	if (ec->busy_polling || bits > 8)1382		acpi_ec_burst_disable(ec);1383 1384	if (ec->global_lock)1385		acpi_release_global_lock(glk);1386 1387unlock:1388	mutex_unlock(&ec->mutex);1389 1390	switch (result) {1391	case -EINVAL:1392		return AE_BAD_PARAMETER;1393	case -ENODEV:1394		return AE_NOT_FOUND;1395	case -ETIME:1396		return AE_TIME;1397	case 0:1398		return AE_OK;1399	default:1400		return AE_ERROR;1401	}1402}1403 1404/* --------------------------------------------------------------------------1405 *                             Driver Interface1406 * -------------------------------------------------------------------------- */1407 1408static acpi_status1409ec_parse_io_ports(struct acpi_resource *resource, void *context);1410 1411static void acpi_ec_free(struct acpi_ec *ec)1412{1413	if (first_ec == ec)1414		first_ec = NULL;1415	if (boot_ec == ec)1416		boot_ec = NULL;1417	kfree(ec);1418}1419 1420static struct acpi_ec *acpi_ec_alloc(void)1421{1422	struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);1423 1424	if (!ec)1425		return NULL;1426	mutex_init(&ec->mutex);1427	init_waitqueue_head(&ec->wait);1428	INIT_LIST_HEAD(&ec->list);1429	spin_lock_init(&ec->lock);1430	INIT_WORK(&ec->work, acpi_ec_event_handler);1431	ec->timestamp = jiffies;1432	ec->busy_polling = true;1433	ec->polling_guard = 0;1434	ec->gpe = -1;1435	ec->irq = -1;1436	return ec;1437}1438 1439static acpi_status1440acpi_ec_register_query_methods(acpi_handle handle, u32 level,1441			       void *context, void **return_value)1442{1443	char node_name[5];1444	struct acpi_buffer buffer = { sizeof(node_name), node_name };1445	struct acpi_ec *ec = context;1446	int value = 0;1447	acpi_status status;1448 1449	status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);1450 1451	if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1)1452		acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);1453	return AE_OK;1454}1455 1456static acpi_status1457ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)1458{1459	acpi_status status;1460	unsigned long long tmp = 0;1461	struct acpi_ec *ec = context;1462 1463	/* clear addr values, ec_parse_io_ports depend on it */1464	ec->command_addr = ec->data_addr = 0;1465 1466	status = acpi_walk_resources(handle, METHOD_NAME__CRS,1467				     ec_parse_io_ports, ec);1468	if (ACPI_FAILURE(status))1469		return status;1470	if (ec->data_addr == 0 || ec->command_addr == 0)1471		return AE_OK;1472 1473	/* Get GPE bit assignment (EC events). */1474	/* TODO: Add support for _GPE returning a package */1475	status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);1476	if (ACPI_SUCCESS(status))1477		ec->gpe = tmp;1478	/*1479	 * Errors are non-fatal, allowing for ACPI Reduced Hardware1480	 * platforms which use GpioInt instead of GPE.1481	 */1482 1483	/* Use the global lock for all EC transactions? */1484	tmp = 0;1485	acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);1486	ec->global_lock = tmp;1487	ec->handle = handle;1488	return AE_CTRL_TERMINATE;1489}1490 1491static bool install_gpe_event_handler(struct acpi_ec *ec)1492{1493	acpi_status status;1494 1495	status = acpi_install_gpe_raw_handler(NULL, ec->gpe,1496					      ACPI_GPE_EDGE_TRIGGERED,1497					      &acpi_ec_gpe_handler, ec);1498	if (ACPI_FAILURE(status))1499		return false;1500 1501	if (test_bit(EC_FLAGS_STARTED, &ec->flags) && ec->reference_count >= 1)1502		acpi_ec_enable_gpe(ec, true);1503 1504	return true;1505}1506 1507static bool install_gpio_irq_event_handler(struct acpi_ec *ec)1508{1509	return request_threaded_irq(ec->irq, NULL, acpi_ec_irq_handler,1510				    IRQF_SHARED | IRQF_ONESHOT, "ACPI EC", ec) >= 0;1511}1512 1513/**1514 * ec_install_handlers - Install service callbacks and register query methods.1515 * @ec: Target EC.1516 * @device: ACPI device object corresponding to @ec.1517 * @call_reg: If _REG should be called to notify OpRegion availability1518 *1519 * Install a handler for the EC address space type unless it has been installed1520 * already.  If @device is not NULL, also look for EC query methods in the1521 * namespace and register them, and install an event (either GPE or GPIO IRQ)1522 * handler for the EC, if possible.1523 *1524 * Return:1525 * -ENODEV if the address space handler cannot be installed, which means1526 *  "unable to handle transactions",1527 * -EPROBE_DEFER if GPIO IRQ acquisition needs to be deferred,1528 * or 0 (success) otherwise.1529 */1530static int ec_install_handlers(struct acpi_ec *ec, struct acpi_device *device,1531			       bool call_reg)1532{1533	acpi_status status;1534 1535	acpi_ec_start(ec, false);1536 1537	if (!test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {1538		acpi_handle scope_handle = ec == first_ec ? ACPI_ROOT_OBJECT : ec->handle;1539 1540		acpi_ec_enter_noirq(ec);1541		status = acpi_install_address_space_handler_no_reg(scope_handle,1542								   ACPI_ADR_SPACE_EC,1543								   &acpi_ec_space_handler,1544								   NULL, ec);1545		if (ACPI_FAILURE(status)) {1546			acpi_ec_stop(ec, false);1547			return -ENODEV;1548		}1549		set_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);1550	}1551 1552	if (call_reg && !test_bit(EC_FLAGS_EC_REG_CALLED, &ec->flags)) {1553		acpi_execute_reg_methods(ec->handle, ACPI_UINT32_MAX, ACPI_ADR_SPACE_EC);1554		set_bit(EC_FLAGS_EC_REG_CALLED, &ec->flags);1555	}1556 1557	if (!device)1558		return 0;1559 1560	if (ec->gpe < 0) {1561		/* ACPI reduced hardware platforms use a GpioInt from _CRS. */1562		int irq = acpi_dev_gpio_irq_get(device, 0);1563		/*1564		 * Bail out right away for deferred probing or complete the1565		 * initialization regardless of any other errors.1566		 */1567		if (irq == -EPROBE_DEFER)1568			return -EPROBE_DEFER;1569		else if (irq >= 0)1570			ec->irq = irq;1571	}1572 1573	if (!test_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags)) {1574		/* Find and register all query methods */1575		acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,1576				    acpi_ec_register_query_methods,1577				    NULL, ec, NULL);1578		set_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags);1579	}1580	if (!test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {1581		bool ready = false;1582 1583		if (ec->gpe >= 0)1584			ready = install_gpe_event_handler(ec);1585		else if (ec->irq >= 0)1586			ready = install_gpio_irq_event_handler(ec);1587 1588		if (ready) {1589			set_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags);1590			acpi_ec_leave_noirq(ec);1591		}1592		/*1593		 * Failures to install an event handler are not fatal, because1594		 * the EC can be polled for events.1595		 */1596	}1597	/* EC is fully operational, allow queries */1598	acpi_ec_enable_event(ec);1599 1600	return 0;1601}1602 1603static void ec_remove_handlers(struct acpi_ec *ec)1604{1605	acpi_handle scope_handle = ec == first_ec ? ACPI_ROOT_OBJECT : ec->handle;1606 1607	if (test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {1608		if (ACPI_FAILURE(acpi_remove_address_space_handler(1609						scope_handle,1610						ACPI_ADR_SPACE_EC,1611						&acpi_ec_space_handler)))1612			pr_err("failed to remove space handler\n");1613		clear_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);1614	}1615 1616	/*1617	 * Stops handling the EC transactions after removing the operation1618	 * region handler. This is required because _REG(DISCONNECT)1619	 * invoked during the removal can result in new EC transactions.1620	 *1621	 * Flushes the EC requests and thus disables the GPE before1622	 * removing the GPE handler. This is required by the current ACPICA1623	 * GPE core. ACPICA GPE core will automatically disable a GPE when1624	 * it is indicated but there is no way to handle it. So the drivers1625	 * must disable the GPEs prior to removing the GPE handlers.1626	 */1627	acpi_ec_stop(ec, false);1628 1629	if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {1630		if (ec->gpe >= 0 &&1631		    ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,1632				 &acpi_ec_gpe_handler)))1633			pr_err("failed to remove gpe handler\n");1634 1635		if (ec->irq >= 0)1636			free_irq(ec->irq, ec);1637 1638		clear_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags);1639	}1640	if (test_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags)) {1641		acpi_ec_remove_query_handlers(ec, true, 0);1642		clear_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags);1643	}1644}1645 1646static int acpi_ec_setup(struct acpi_ec *ec, struct acpi_device *device, bool call_reg)1647{1648	int ret;1649 1650	/* First EC capable of handling transactions */1651	if (!first_ec)1652		first_ec = ec;1653 1654	ret = ec_install_handlers(ec, device, call_reg);1655	if (ret) {1656		if (ec == first_ec)1657			first_ec = NULL;1658 1659		return ret;1660	}1661 1662	pr_info("EC_CMD/EC_SC=0x%lx, EC_DATA=0x%lx\n", ec->command_addr,1663		ec->data_addr);1664 1665	if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {1666		if (ec->gpe >= 0)1667			pr_info("GPE=0x%x\n", ec->gpe);1668		else1669			pr_info("IRQ=%d\n", ec->irq);1670	}1671 1672	return ret;1673}1674 1675static int acpi_ec_add(struct acpi_device *device)1676{1677	struct acpi_ec *ec;1678	int ret;1679 1680	strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);1681	strcpy(acpi_device_class(device), ACPI_EC_CLASS);1682 1683	if (boot_ec && (boot_ec->handle == device->handle ||1684	    !strcmp(acpi_device_hid(device), ACPI_ECDT_HID))) {1685		/* Fast path: this device corresponds to the boot EC. */1686		ec = boot_ec;1687	} else {1688		acpi_status status;1689 1690		ec = acpi_ec_alloc();1691		if (!ec)1692			return -ENOMEM;1693 1694		status = ec_parse_device(device->handle, 0, ec, NULL);1695		if (status != AE_CTRL_TERMINATE) {1696			ret = -EINVAL;1697			goto err;1698		}1699 1700		if (boot_ec && ec->command_addr == boot_ec->command_addr &&1701		    ec->data_addr == boot_ec->data_addr) {1702			/*1703			 * Trust PNP0C09 namespace location rather than ECDT ID.1704			 * But trust ECDT GPE rather than _GPE because of ASUS1705			 * quirks. So do not change boot_ec->gpe to ec->gpe,1706			 * except when the TRUST_DSDT_GPE quirk is set.1707			 */1708			boot_ec->handle = ec->handle;1709 1710			if (EC_FLAGS_TRUST_DSDT_GPE)1711				boot_ec->gpe = ec->gpe;1712 1713			acpi_handle_debug(ec->handle, "duplicated.\n");1714			acpi_ec_free(ec);1715			ec = boot_ec;1716		}1717	}1718 1719	ret = acpi_ec_setup(ec, device, true);1720	if (ret)1721		goto err;1722 1723	if (ec == boot_ec)1724		acpi_handle_info(boot_ec->handle,1725				 "Boot %s EC initialization complete\n",1726				 boot_ec_is_ecdt ? "ECDT" : "DSDT");1727 1728	acpi_handle_info(ec->handle,1729			 "EC: Used to handle transactions and events\n");1730 1731	device->driver_data = ec;1732 1733	ret = !!request_region(ec->data_addr, 1, "EC data");1734	WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);1735	ret = !!request_region(ec->command_addr, 1, "EC cmd");1736	WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);1737 1738	/* Reprobe devices depending on the EC */1739	acpi_dev_clear_dependencies(device);1740 1741	acpi_handle_debug(ec->handle, "enumerated.\n");1742	return 0;1743 1744err:1745	if (ec != boot_ec)1746		acpi_ec_free(ec);1747 1748	return ret;1749}1750 1751static void acpi_ec_remove(struct acpi_device *device)1752{1753	struct acpi_ec *ec;1754 1755	if (!device)1756		return;1757 1758	ec = acpi_driver_data(device);1759	release_region(ec->data_addr, 1);1760	release_region(ec->command_addr, 1);1761	device->driver_data = NULL;1762	if (ec != boot_ec) {1763		ec_remove_handlers(ec);1764		acpi_ec_free(ec);1765	}1766}1767 1768void acpi_ec_register_opregions(struct acpi_device *adev)1769{1770	if (first_ec && first_ec->handle != adev->handle)1771		acpi_execute_reg_methods(adev->handle, 1, ACPI_ADR_SPACE_EC);1772}1773 1774static acpi_status1775ec_parse_io_ports(struct acpi_resource *resource, void *context)1776{1777	struct acpi_ec *ec = context;1778 1779	if (resource->type != ACPI_RESOURCE_TYPE_IO)1780		return AE_OK;1781 1782	/*1783	 * The first address region returned is the data port, and1784	 * the second address region returned is the status/command1785	 * port.1786	 */1787	if (ec->data_addr == 0)1788		ec->data_addr = resource->data.io.minimum;1789	else if (ec->command_addr == 0)1790		ec->command_addr = resource->data.io.minimum;1791	else1792		return AE_CTRL_TERMINATE;1793 1794	return AE_OK;1795}1796 1797static const struct acpi_device_id ec_device_ids[] = {1798	{"PNP0C09", 0},1799	{ACPI_ECDT_HID, 0},1800	{"", 0},1801};1802 1803/*1804 * This function is not Windows-compatible as Windows never enumerates the1805 * namespace EC before the main ACPI device enumeration process. It is1806 * retained for historical reason and will be deprecated in the future.1807 */1808void __init acpi_ec_dsdt_probe(void)1809{1810	struct acpi_ec *ec;1811	acpi_status status;1812	int ret;1813 1814	/*1815	 * If a platform has ECDT, there is no need to proceed as the1816	 * following probe is not a part of the ACPI device enumeration,1817	 * executing _STA is not safe, and thus this probe may risk of1818	 * picking up an invalid EC device.1819	 */1820	if (boot_ec)1821		return;1822 1823	ec = acpi_ec_alloc();1824	if (!ec)1825		return;1826 1827	/*1828	 * At this point, the namespace is initialized, so start to find1829	 * the namespace objects.1830	 */1831	status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device, ec, NULL);1832	if (ACPI_FAILURE(status) || !ec->handle) {1833		acpi_ec_free(ec);1834		return;1835	}1836 1837	/*1838	 * When the DSDT EC is available, always re-configure boot EC to1839	 * have _REG evaluated. _REG can only be evaluated after the1840	 * namespace initialization.1841	 * At this point, the GPE is not fully initialized, so do not to1842	 * handle the events.1843	 */1844	ret = acpi_ec_setup(ec, NULL, true);1845	if (ret) {1846		acpi_ec_free(ec);1847		return;1848	}1849 1850	boot_ec = ec;1851 1852	acpi_handle_info(ec->handle,1853			 "Boot DSDT EC used to handle transactions\n");1854}1855 1856/*1857 * acpi_ec_ecdt_start - Finalize the boot ECDT EC initialization.1858 *1859 * First, look for an ACPI handle for the boot ECDT EC if acpi_ec_add() has not1860 * found a matching object in the namespace.1861 *1862 * Next, in case the DSDT EC is not functioning, it is still necessary to1863 * provide a functional ECDT EC to handle events, so add an extra device object1864 * to represent it (see https://bugzilla.kernel.org/show_bug.cgi?id=115021).1865 *1866 * This is useful on platforms with valid ECDT and invalid DSDT EC settings,1867 * like ASUS X550ZE (see https://bugzilla.kernel.org/show_bug.cgi?id=196847).1868 */1869static void __init acpi_ec_ecdt_start(void)1870{1871	struct acpi_table_ecdt *ecdt_ptr;1872	acpi_handle handle;1873	acpi_status status;1874 1875	/* Bail out if a matching EC has been found in the namespace. */1876	if (!boot_ec || boot_ec->handle != ACPI_ROOT_OBJECT)1877		return;1878 1879	/* Look up the object pointed to from the ECDT in the namespace. */1880	status = acpi_get_table(ACPI_SIG_ECDT, 1,1881				(struct acpi_table_header **)&ecdt_ptr);1882	if (ACPI_FAILURE(status))1883		return;1884 1885	status = acpi_get_handle(NULL, ecdt_ptr->id, &handle);1886	if (ACPI_SUCCESS(status)) {1887		boot_ec->handle = handle;1888 1889		/* Add a special ACPI device object to represent the boot EC. */1890		acpi_bus_register_early_device(ACPI_BUS_TYPE_ECDT_EC);1891	}1892 1893	acpi_put_table((struct acpi_table_header *)ecdt_ptr);1894}1895 1896/*1897 * On some hardware it is necessary to clear events accumulated by the EC during1898 * sleep. These ECs stop reporting GPEs until they are manually polled, if too1899 * many events are accumulated. (e.g. Samsung Series 5/9 notebooks)1900 *1901 * https://bugzilla.kernel.org/show_bug.cgi?id=441611902 *1903 * Ideally, the EC should also be instructed NOT to accumulate events during1904 * sleep (which Windows seems to do somehow), but the interface to control this1905 * behaviour is not known at this time.1906 *1907 * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx,1908 * however it is very likely that other Samsung models are affected.1909 *1910 * On systems which don't accumulate _Q events during sleep, this extra check1911 * should be harmless.1912 */1913static int ec_clear_on_resume(const struct dmi_system_id *id)1914{1915	pr_debug("Detected system needing EC poll on resume.\n");1916	EC_FLAGS_CLEAR_ON_RESUME = 1;1917	ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;1918	return 0;1919}1920 1921/*1922 * Some ECDTs contain wrong register addresses.1923 * MSI MS-171F1924 * https://bugzilla.kernel.org/show_bug.cgi?id=124611925 */1926static int ec_correct_ecdt(const struct dmi_system_id *id)1927{1928	pr_debug("Detected system needing ECDT address correction.\n");1929	EC_FLAGS_CORRECT_ECDT = 1;1930	return 0;1931}1932 1933/*1934 * Some ECDTs contain wrong GPE setting, but they share the same port addresses1935 * with DSDT EC, don't duplicate the DSDT EC with ECDT EC in this case.1936 * https://bugzilla.kernel.org/show_bug.cgi?id=2099891937 */1938static int ec_honor_dsdt_gpe(const struct dmi_system_id *id)1939{1940	pr_debug("Detected system needing DSDT GPE setting.\n");1941	EC_FLAGS_TRUST_DSDT_GPE = 1;1942	return 0;1943}1944 1945static const struct dmi_system_id ec_dmi_table[] __initconst = {1946	{1947		/*1948		 * MSI MS-171F1949		 * https://bugzilla.kernel.org/show_bug.cgi?id=124611950		 */1951		.callback = ec_correct_ecdt,1952		.matches = {1953			DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star"),1954			DMI_MATCH(DMI_PRODUCT_NAME, "MS-171F"),1955		},1956	},1957	{1958		/*1959		 * HP Pavilion Gaming Laptop 15-cx0xxx1960		 * https://bugzilla.kernel.org/show_bug.cgi?id=2099891961		 */1962		.callback = ec_honor_dsdt_gpe,1963		.matches = {1964			DMI_MATCH(DMI_SYS_VENDOR, "HP"),1965			DMI_MATCH(DMI_PRODUCT_NAME, "HP Pavilion Gaming Laptop 15-cx0xxx"),1966		},1967	},1968	{1969		/*1970		 * HP Pavilion Gaming Laptop 15-cx0041ur1971		 */1972		.callback = ec_honor_dsdt_gpe,1973		.matches = {1974			DMI_MATCH(DMI_SYS_VENDOR, "HP"),1975			DMI_MATCH(DMI_PRODUCT_NAME, "HP 15-cx0041ur"),1976		},1977	},1978	{1979		/*1980		 * HP Pavilion Gaming Laptop 15-dk1xxx1981		 * https://github.com/systemd/systemd/issues/289421982		 */1983		.callback = ec_honor_dsdt_gpe,1984		.matches = {1985			DMI_MATCH(DMI_SYS_VENDOR, "HP"),1986			DMI_MATCH(DMI_PRODUCT_NAME, "HP Pavilion Gaming Laptop 15-dk1xxx"),1987		},1988	},1989	{1990		/*1991		 * HP 250 G7 Notebook PC1992		 */1993		.callback = ec_honor_dsdt_gpe,1994		.matches = {1995			DMI_MATCH(DMI_SYS_VENDOR, "HP"),1996			DMI_MATCH(DMI_PRODUCT_NAME, "HP 250 G7 Notebook PC"),1997		},1998	},1999	{2000		/*2001		 * Samsung hardware2002		 * https://bugzilla.kernel.org/show_bug.cgi?id=441612003		 */2004		.callback = ec_clear_on_resume,2005		.matches = {2006			DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),2007		},2008	},2009	{}2010};2011 2012void __init acpi_ec_ecdt_probe(void)2013{2014	struct acpi_table_ecdt *ecdt_ptr;2015	struct acpi_ec *ec;2016	acpi_status status;2017	int ret;2018 2019	/* Generate a boot ec context. */2020	dmi_check_system(ec_dmi_table);2021	status = acpi_get_table(ACPI_SIG_ECDT, 1,2022				(struct acpi_table_header **)&ecdt_ptr);2023	if (ACPI_FAILURE(status))2024		return;2025 2026	if (!ecdt_ptr->control.address || !ecdt_ptr->data.address) {2027		/*2028		 * Asus X50GL:2029		 * https://bugzilla.kernel.org/show_bug.cgi?id=118802030		 */2031		goto out;2032	}2033 2034	ec = acpi_ec_alloc();2035	if (!ec)2036		goto out;2037 2038	if (EC_FLAGS_CORRECT_ECDT) {2039		ec->command_addr = ecdt_ptr->data.address;2040		ec->data_addr = ecdt_ptr->control.address;2041	} else {2042		ec->command_addr = ecdt_ptr->control.address;2043		ec->data_addr = ecdt_ptr->data.address;2044	}2045 2046	/*2047	 * Ignore the GPE value on Reduced Hardware platforms.2048	 * Some products have this set to an erroneous value.2049	 */2050	if (!acpi_gbl_reduced_hardware)2051		ec->gpe = ecdt_ptr->gpe;2052 2053	ec->handle = ACPI_ROOT_OBJECT;2054 2055	/*2056	 * At this point, the namespace is not initialized, so do not find2057	 * the namespace objects, or handle the events.2058	 */2059	ret = acpi_ec_setup(ec, NULL, false);2060	if (ret) {2061		acpi_ec_free(ec);2062		goto out;2063	}2064 2065	boot_ec = ec;2066	boot_ec_is_ecdt = true;2067 2068	pr_info("Boot ECDT EC used to handle transactions\n");2069 2070out:2071	acpi_put_table((struct acpi_table_header *)ecdt_ptr);2072}2073 2074#ifdef CONFIG_PM_SLEEP2075static int acpi_ec_suspend(struct device *dev)2076{2077	struct acpi_ec *ec =2078		acpi_driver_data(to_acpi_device(dev));2079 2080	if (!pm_suspend_no_platform() && ec_freeze_events)2081		acpi_ec_disable_event(ec);2082	return 0;2083}2084 2085static int acpi_ec_suspend_noirq(struct device *dev)2086{2087	struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));2088 2089	/*2090	 * The SCI handler doesn't run at this point, so the GPE can be2091	 * masked at the low level without side effects.2092	 */2093	if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&2094	    ec->gpe >= 0 && ec->reference_count >= 1)2095		acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);2096 2097	acpi_ec_enter_noirq(ec);2098 2099	return 0;2100}2101 2102static int acpi_ec_resume_noirq(struct device *dev)2103{2104	struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));2105 2106	acpi_ec_leave_noirq(ec);2107 2108	if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&2109	    ec->gpe >= 0 && ec->reference_count >= 1)2110		acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);2111 2112	return 0;2113}2114 2115static int acpi_ec_resume(struct device *dev)2116{2117	struct acpi_ec *ec =2118		acpi_driver_data(to_acpi_device(dev));2119 2120	acpi_ec_enable_event(ec);2121	return 0;2122}2123 2124void acpi_ec_mark_gpe_for_wake(void)2125{2126	if (first_ec && !ec_no_wakeup)2127		acpi_mark_gpe_for_wake(NULL, first_ec->gpe);2128}2129EXPORT_SYMBOL_GPL(acpi_ec_mark_gpe_for_wake);2130 2131void acpi_ec_set_gpe_wake_mask(u8 action)2132{2133	if (pm_suspend_no_platform() && first_ec && !ec_no_wakeup)2134		acpi_set_gpe_wake_mask(NULL, first_ec->gpe, action);2135}2136 2137static bool acpi_ec_work_in_progress(struct acpi_ec *ec)2138{2139	return ec->events_in_progress + ec->queries_in_progress > 0;2140}2141 2142bool acpi_ec_dispatch_gpe(void)2143{2144	bool work_in_progress = false;2145 2146	if (!first_ec)2147		return acpi_any_gpe_status_set(U32_MAX);2148 2149	/*2150	 * Report wakeup if the status bit is set for any enabled GPE other2151	 * than the EC one.2152	 */2153	if (acpi_any_gpe_status_set(first_ec->gpe))2154		return true;2155 2156	/*2157	 * Cancel the SCI wakeup and process all pending events in case there2158	 * are any wakeup ones in there.2159	 *2160	 * Note that if any non-EC GPEs are active at this point, the SCI will2161	 * retrigger after the rearming in acpi_s2idle_wake(), so no events2162	 * should be missed by canceling the wakeup here.2163	 */2164	pm_system_cancel_wakeup();2165 2166	/*2167	 * Dispatch the EC GPE in-band, but do not report wakeup in any case2168	 * to allow the caller to process events properly after that.2169	 */2170	spin_lock_irq(&first_ec->lock);2171 2172	if (acpi_ec_gpe_status_set(first_ec)) {2173		pm_pr_dbg("ACPI EC GPE status set\n");2174 2175		clear_gpe_and_advance_transaction(first_ec, false);2176		work_in_progress = acpi_ec_work_in_progress(first_ec);2177	}2178 2179	spin_unlock_irq(&first_ec->lock);2180 2181	if (!work_in_progress)2182		return false;2183 2184	pm_pr_dbg("ACPI EC GPE dispatched\n");2185 2186	/* Drain EC work. */2187	do {2188		acpi_ec_flush_work();2189 2190		pm_pr_dbg("ACPI EC work flushed\n");2191 2192		spin_lock_irq(&first_ec->lock);2193 2194		work_in_progress = acpi_ec_work_in_progress(first_ec);2195 2196		spin_unlock_irq(&first_ec->lock);2197	} while (work_in_progress && !pm_wakeup_pending());2198 2199	return false;2200}2201#endif /* CONFIG_PM_SLEEP */2202 2203static const struct dev_pm_ops acpi_ec_pm = {2204	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend_noirq, acpi_ec_resume_noirq)2205	SET_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend, acpi_ec_resume)2206};2207 2208static int param_set_event_clearing(const char *val,2209				    const struct kernel_param *kp)2210{2211	int result = 0;2212 2213	if (!strncmp(val, "status", sizeof("status") - 1)) {2214		ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;2215		pr_info("Assuming SCI_EVT clearing on EC_SC accesses\n");2216	} else if (!strncmp(val, "query", sizeof("query") - 1)) {2217		ec_event_clearing = ACPI_EC_EVT_TIMING_QUERY;2218		pr_info("Assuming SCI_EVT clearing on QR_EC writes\n");2219	} else if (!strncmp(val, "event", sizeof("event") - 1)) {2220		ec_event_clearing = ACPI_EC_EVT_TIMING_EVENT;2221		pr_info("Assuming SCI_EVT clearing on event reads\n");2222	} else2223		result = -EINVAL;2224	return result;2225}2226 2227static int param_get_event_clearing(char *buffer,2228				    const struct kernel_param *kp)2229{2230	switch (ec_event_clearing) {2231	case ACPI_EC_EVT_TIMING_STATUS:2232		return sprintf(buffer, "status\n");2233	case ACPI_EC_EVT_TIMING_QUERY:2234		return sprintf(buffer, "query\n");2235	case ACPI_EC_EVT_TIMING_EVENT:2236		return sprintf(buffer, "event\n");2237	default:2238		return sprintf(buffer, "invalid\n");2239	}2240	return 0;2241}2242 2243module_param_call(ec_event_clearing, param_set_event_clearing, param_get_event_clearing,2244		  NULL, 0644);2245MODULE_PARM_DESC(ec_event_clearing, "Assumed SCI_EVT clearing timing");2246 2247static struct acpi_driver acpi_ec_driver = {2248	.name = "ec",2249	.class = ACPI_EC_CLASS,2250	.ids = ec_device_ids,2251	.ops = {2252		.add = acpi_ec_add,2253		.remove = acpi_ec_remove,2254		},2255	.drv.pm = &acpi_ec_pm,2256};2257 2258static void acpi_ec_destroy_workqueues(void)2259{2260	if (ec_wq) {2261		destroy_workqueue(ec_wq);2262		ec_wq = NULL;2263	}2264	if (ec_query_wq) {2265		destroy_workqueue(ec_query_wq);2266		ec_query_wq = NULL;2267	}2268}2269 2270static int acpi_ec_init_workqueues(void)2271{2272	if (!ec_wq)2273		ec_wq = alloc_ordered_workqueue("kec", 0);2274 2275	if (!ec_query_wq)2276		ec_query_wq = alloc_workqueue("kec_query", 0, ec_max_queries);2277 2278	if (!ec_wq || !ec_query_wq) {2279		acpi_ec_destroy_workqueues();2280		return -ENODEV;2281	}2282	return 0;2283}2284 2285static const struct dmi_system_id acpi_ec_no_wakeup[] = {2286	{2287		.matches = {2288			DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),2289			DMI_MATCH(DMI_PRODUCT_FAMILY, "Thinkpad X1 Carbon 6th"),2290		},2291	},2292	{2293		.matches = {2294			DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),2295			DMI_MATCH(DMI_PRODUCT_FAMILY, "ThinkPad X1 Yoga 3rd"),2296		},2297	},2298	{2299		.matches = {2300			DMI_MATCH(DMI_SYS_VENDOR, "HP"),2301			DMI_MATCH(DMI_PRODUCT_FAMILY, "103C_5336AN HP ZHAN 66 Pro"),2302		},2303	},2304	{ },2305};2306 2307void __init acpi_ec_init(void)2308{2309	int result;2310 2311	result = acpi_ec_init_workqueues();2312	if (result)2313		return;2314 2315	/*2316	 * Disable EC wakeup on following systems to prevent periodic2317	 * wakeup from EC GPE.2318	 */2319	if (dmi_check_system(acpi_ec_no_wakeup)) {2320		ec_no_wakeup = true;2321		pr_debug("Disabling EC wakeup on suspend-to-idle\n");2322	}2323 2324	/* Driver must be registered after acpi_ec_init_workqueues(). */2325	acpi_bus_register_driver(&acpi_ec_driver);2326 2327	acpi_ec_ecdt_start();2328}2329 2330/* EC driver currently not unloadable */2331#if 02332static void __exit acpi_ec_exit(void)2333{2334 2335	acpi_bus_unregister_driver(&acpi_ec_driver);2336	acpi_ec_destroy_workqueues();2337}2338#endif	/* 0 */2339