diff options
Diffstat (limited to 'drivers/acpi/ec.c')
| -rw-r--r-- | drivers/acpi/ec.c | 2177 |
1 files changed, 2177 insertions, 0 deletions
diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c new file mode 100644 index 000000000..e3df3dda0 --- /dev/null +++ b/drivers/acpi/ec.c @@ -0,0 +1,2177 @@ +/* + * ec.c - ACPI Embedded Controller Driver (v3) + * + * Copyright (C) 2001-2015 Intel Corporation + * Author: 2014, 2015 Lv Zheng <lv.zheng@intel.com> + * 2006, 2007 Alexey Starikovskiy <alexey.y.starikovskiy@intel.com> + * 2006 Denis Sadykov <denis.m.sadykov@intel.com> + * 2004 Luming Yu <luming.yu@intel.com> + * 2001, 2002 Andy Grover <andrew.grover@intel.com> + * 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com> + * Copyright (C) 2008 Alexey Starikovskiy <astarikovskiy@suse.de> + * + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or (at + * your option) any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + */ + +/* Uncomment next line to get verbose printout */ +/* #define DEBUG */ +#define pr_fmt(fmt) "ACPI: EC: " fmt + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/types.h> +#include <linux/delay.h> +#include <linux/interrupt.h> +#include <linux/list.h> +#include <linux/spinlock.h> +#include <linux/slab.h> +#include <linux/acpi.h> +#include <linux/dmi.h> +#include <asm/io.h> + +#include "internal.h" + +#define ACPI_EC_CLASS "embedded_controller" +#define ACPI_EC_DEVICE_NAME "Embedded Controller" +#define ACPI_EC_FILE_INFO "info" + +/* EC status register */ +#define ACPI_EC_FLAG_OBF 0x01 /* Output buffer full */ +#define ACPI_EC_FLAG_IBF 0x02 /* Input buffer full */ +#define ACPI_EC_FLAG_CMD 0x08 /* Input buffer contains a command */ +#define ACPI_EC_FLAG_BURST 0x10 /* burst mode */ +#define ACPI_EC_FLAG_SCI 0x20 /* EC-SCI occurred */ + +/* + * The SCI_EVT clearing timing is not defined by the ACPI specification. + * This leads to lots of practical timing issues for the host EC driver. + * The following variations are defined (from the target EC firmware's + * perspective): + * STATUS: After indicating SCI_EVT edge triggered IRQ to the host, the + * target can clear SCI_EVT at any time so long as the host can see + * the indication by reading the status register (EC_SC). So the + * host should re-check SCI_EVT after the first time the SCI_EVT + * indication is seen, which is the same time the query request + * (QR_EC) is written to the command register (EC_CMD). SCI_EVT set + * at any later time could indicate another event. Normally such + * kind of EC firmware has implemented an event queue and will + * return 0x00 to indicate "no outstanding event". + * QUERY: After seeing the query request (QR_EC) written to the command + * register (EC_CMD) by the host and having prepared the responding + * event value in the data register (EC_DATA), the target can safely + * clear SCI_EVT because the target can confirm that the current + * event is being handled by the host. The host then should check + * SCI_EVT right after reading the event response from the data + * register (EC_DATA). + * EVENT: After seeing the event response read from the data register + * (EC_DATA) by the host, the target can clear SCI_EVT. As the + * target requires time to notice the change in the data register + * (EC_DATA), the host may be required to wait additional guarding + * time before checking the SCI_EVT again. Such guarding may not be + * necessary if the host is notified via another IRQ. + */ +#define ACPI_EC_EVT_TIMING_STATUS 0x00 +#define ACPI_EC_EVT_TIMING_QUERY 0x01 +#define ACPI_EC_EVT_TIMING_EVENT 0x02 + +/* EC commands */ +enum ec_command { + ACPI_EC_COMMAND_READ = 0x80, + ACPI_EC_COMMAND_WRITE = 0x81, + ACPI_EC_BURST_ENABLE = 0x82, + ACPI_EC_BURST_DISABLE = 0x83, + ACPI_EC_COMMAND_QUERY = 0x84, +}; + +#define ACPI_EC_DELAY 500 /* Wait 500ms max. during EC ops */ +#define ACPI_EC_UDELAY_GLK 1000 /* Wait 1ms max. to get global lock */ +#define ACPI_EC_UDELAY_POLL 550 /* Wait 1ms for EC transaction polling */ +#define ACPI_EC_CLEAR_MAX 100 /* Maximum number of events to query + * when trying to clear the EC */ +#define ACPI_EC_MAX_QUERIES 16 /* Maximum number of parallel queries */ + +enum { + EC_FLAGS_QUERY_ENABLED, /* Query is enabled */ + EC_FLAGS_QUERY_PENDING, /* Query is pending */ + EC_FLAGS_QUERY_GUARDING, /* Guard for SCI_EVT check */ + EC_FLAGS_GPE_HANDLER_INSTALLED, /* GPE handler installed */ + EC_FLAGS_EC_HANDLER_INSTALLED, /* OpReg handler installed */ + EC_FLAGS_EVT_HANDLER_INSTALLED, /* _Qxx handlers installed */ + EC_FLAGS_STARTED, /* Driver is started */ + EC_FLAGS_STOPPED, /* Driver is stopped */ + EC_FLAGS_GPE_MASKED, /* GPE masked */ +}; + +#define ACPI_EC_COMMAND_POLL 0x01 /* Available for command byte */ +#define ACPI_EC_COMMAND_COMPLETE 0x02 /* Completed last byte */ + +/* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */ +static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY; +module_param(ec_delay, uint, 0644); +MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes"); + +static unsigned int ec_max_queries __read_mostly = ACPI_EC_MAX_QUERIES; +module_param(ec_max_queries, uint, 0644); +MODULE_PARM_DESC(ec_max_queries, "Maximum parallel _Qxx evaluations"); + +static bool ec_busy_polling __read_mostly; +module_param(ec_busy_polling, bool, 0644); +MODULE_PARM_DESC(ec_busy_polling, "Use busy polling to advance EC transaction"); + +static unsigned int ec_polling_guard __read_mostly = ACPI_EC_UDELAY_POLL; +module_param(ec_polling_guard, uint, 0644); +MODULE_PARM_DESC(ec_polling_guard, "Guard time(us) between EC accesses in polling modes"); + +static unsigned int ec_event_clearing __read_mostly = ACPI_EC_EVT_TIMING_QUERY; + +/* + * If the number of false interrupts per one transaction exceeds + * this threshold, will think there is a GPE storm happened and + * will disable the GPE for normal transaction. + */ +static unsigned int ec_storm_threshold __read_mostly = 8; +module_param(ec_storm_threshold, uint, 0644); +MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm"); + +static bool ec_freeze_events __read_mostly = false; +module_param(ec_freeze_events, bool, 0644); +MODULE_PARM_DESC(ec_freeze_events, "Disabling event handling during suspend/resume"); + +static bool ec_no_wakeup __read_mostly; +module_param(ec_no_wakeup, bool, 0644); +MODULE_PARM_DESC(ec_no_wakeup, "Do not wake up from suspend-to-idle"); + +struct acpi_ec_query_handler { + struct list_head node; + acpi_ec_query_func func; + acpi_handle handle; + void *data; + u8 query_bit; + struct kref kref; +}; + +struct transaction { + const u8 *wdata; + u8 *rdata; + unsigned short irq_count; + u8 command; + u8 wi; + u8 ri; + u8 wlen; + u8 rlen; + u8 flags; +}; + +struct acpi_ec_query { + struct transaction transaction; + struct work_struct work; + struct acpi_ec_query_handler *handler; +}; + +static int acpi_ec_query(struct acpi_ec *ec, u8 *data); +static void advance_transaction(struct acpi_ec *ec); +static void acpi_ec_event_handler(struct work_struct *work); +static void acpi_ec_event_processor(struct work_struct *work); + +struct acpi_ec *boot_ec, *first_ec; +EXPORT_SYMBOL(first_ec); +static bool boot_ec_is_ecdt = false; +static struct workqueue_struct *ec_query_wq; + +static int EC_FLAGS_QUERY_HANDSHAKE; /* Needs QR_EC issued when SCI_EVT set */ +static int EC_FLAGS_CORRECT_ECDT; /* Needs ECDT port address correction */ +static int EC_FLAGS_IGNORE_DSDT_GPE; /* Needs ECDT GPE as correction setting */ +static int EC_FLAGS_CLEAR_ON_RESUME; /* Needs acpi_ec_clear() on boot/resume */ + +/* -------------------------------------------------------------------------- + * Logging/Debugging + * -------------------------------------------------------------------------- */ + +/* + * Splitters used by the developers to track the boundary of the EC + * handling processes. + */ +#ifdef DEBUG +#define EC_DBG_SEP " " +#define EC_DBG_DRV "+++++" +#define EC_DBG_STM "=====" +#define EC_DBG_REQ "*****" +#define EC_DBG_EVT "#####" +#else +#define EC_DBG_SEP "" +#define EC_DBG_DRV +#define EC_DBG_STM +#define EC_DBG_REQ +#define EC_DBG_EVT +#endif + +#define ec_log_raw(fmt, ...) \ + pr_info(fmt "\n", ##__VA_ARGS__) +#define ec_dbg_raw(fmt, ...) \ + pr_debug(fmt "\n", ##__VA_ARGS__) +#define ec_log(filter, fmt, ...) \ + ec_log_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__) +#define ec_dbg(filter, fmt, ...) \ + ec_dbg_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__) + +#define ec_log_drv(fmt, ...) \ + ec_log(EC_DBG_DRV, fmt, ##__VA_ARGS__) +#define ec_dbg_drv(fmt, ...) \ + ec_dbg(EC_DBG_DRV, fmt, ##__VA_ARGS__) +#define ec_dbg_stm(fmt, ...) \ + ec_dbg(EC_DBG_STM, fmt, ##__VA_ARGS__) +#define ec_dbg_req(fmt, ...) \ + ec_dbg(EC_DBG_REQ, fmt, ##__VA_ARGS__) +#define ec_dbg_evt(fmt, ...) \ + ec_dbg(EC_DBG_EVT, fmt, ##__VA_ARGS__) +#define ec_dbg_ref(ec, fmt, ...) \ + ec_dbg_raw("%lu: " fmt, ec->reference_count, ## __VA_ARGS__) + +/* -------------------------------------------------------------------------- + * Device Flags + * -------------------------------------------------------------------------- */ + +static bool acpi_ec_started(struct acpi_ec *ec) +{ + return test_bit(EC_FLAGS_STARTED, &ec->flags) && + !test_bit(EC_FLAGS_STOPPED, &ec->flags); +} + +static bool acpi_ec_event_enabled(struct acpi_ec *ec) +{ + /* + * There is an OSPM early stage logic. During the early stages + * (boot/resume), OSPMs shouldn't enable the event handling, only + * the EC transactions are allowed to be performed. + */ + if (!test_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags)) + return false; + /* + * However, disabling the event handling is experimental for late + * stage (suspend), and is controlled by the boot parameter of + * "ec_freeze_events": + * 1. true: The EC event handling is disabled before entering + * the noirq stage. + * 2. false: The EC event handling is automatically disabled as + * soon as the EC driver is stopped. + */ + if (ec_freeze_events) + return acpi_ec_started(ec); + else + return test_bit(EC_FLAGS_STARTED, &ec->flags); +} + +static bool acpi_ec_flushed(struct acpi_ec *ec) +{ + return ec->reference_count == 1; +} + +/* -------------------------------------------------------------------------- + * EC Registers + * -------------------------------------------------------------------------- */ + +static inline u8 acpi_ec_read_status(struct acpi_ec *ec) +{ + u8 x = inb(ec->command_addr); + + ec_dbg_raw("EC_SC(R) = 0x%2.2x " + "SCI_EVT=%d BURST=%d CMD=%d IBF=%d OBF=%d", + x, + !!(x & ACPI_EC_FLAG_SCI), + !!(x & ACPI_EC_FLAG_BURST), + !!(x & ACPI_EC_FLAG_CMD), + !!(x & ACPI_EC_FLAG_IBF), + !!(x & ACPI_EC_FLAG_OBF)); + return x; +} + +static inline u8 acpi_ec_read_data(struct acpi_ec *ec) +{ + u8 x = inb(ec->data_addr); + + ec->timestamp = jiffies; + ec_dbg_raw("EC_DATA(R) = 0x%2.2x", x); + return x; +} + +static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command) +{ + ec_dbg_raw("EC_SC(W) = 0x%2.2x", command); + outb(command, ec->command_addr); + ec->timestamp = jiffies; +} + +static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data) +{ + ec_dbg_raw("EC_DATA(W) = 0x%2.2x", data); + outb(data, ec->data_addr); + ec->timestamp = jiffies; +} + +#if defined(DEBUG) || defined(CONFIG_DYNAMIC_DEBUG) +static const char *acpi_ec_cmd_string(u8 cmd) +{ + switch (cmd) { + case 0x80: + return "RD_EC"; + case 0x81: + return "WR_EC"; + case 0x82: + return "BE_EC"; + case 0x83: + return "BD_EC"; + case 0x84: + return "QR_EC"; + } + return "UNKNOWN"; +} +#else +#define acpi_ec_cmd_string(cmd) "UNDEF" +#endif + +/* -------------------------------------------------------------------------- + * GPE Registers + * -------------------------------------------------------------------------- */ + +static inline bool acpi_ec_is_gpe_raised(struct acpi_ec *ec) +{ + acpi_event_status gpe_status = 0; + + (void)acpi_get_gpe_status(NULL, ec->gpe, &gpe_status); + return (gpe_status & ACPI_EVENT_FLAG_STATUS_SET) ? true : false; +} + +static inline void acpi_ec_enable_gpe(struct acpi_ec *ec, bool open) +{ + if (open) + acpi_enable_gpe(NULL, ec->gpe); + else { + BUG_ON(ec->reference_count < 1); + acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE); + } + if (acpi_ec_is_gpe_raised(ec)) { + /* + * On some platforms, EN=1 writes cannot trigger GPE. So + * software need to manually trigger a pseudo GPE event on + * EN=1 writes. + */ + ec_dbg_raw("Polling quirk"); + advance_transaction(ec); + } +} + +static inline void acpi_ec_disable_gpe(struct acpi_ec *ec, bool close) +{ + if (close) + acpi_disable_gpe(NULL, ec->gpe); + else { + BUG_ON(ec->reference_count < 1); + acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE); + } +} + +static inline void acpi_ec_clear_gpe(struct acpi_ec *ec) +{ + /* + * GPE STS is a W1C register, which means: + * 1. Software can clear it without worrying about clearing other + * GPEs' STS bits when the hardware sets them in parallel. + * 2. As long as software can ensure only clearing it when it is + * set, hardware won't set it in parallel. + * So software can clear GPE in any contexts. + * Warning: do not move the check into advance_transaction() as the + * EC commands will be sent without GPE raised. + */ + if (!acpi_ec_is_gpe_raised(ec)) + return; + acpi_clear_gpe(NULL, ec->gpe); +} + +/* -------------------------------------------------------------------------- + * Transaction Management + * -------------------------------------------------------------------------- */ + +static void acpi_ec_submit_request(struct acpi_ec *ec) +{ + ec->reference_count++; + if (test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags) && + ec->reference_count == 1) + acpi_ec_enable_gpe(ec, true); +} + +static void acpi_ec_complete_request(struct acpi_ec *ec) +{ + bool flushed = false; + + ec->reference_count--; + if (test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags) && + ec->reference_count == 0) + acpi_ec_disable_gpe(ec, true); + flushed = acpi_ec_flushed(ec); + if (flushed) + wake_up(&ec->wait); +} + +static void acpi_ec_mask_gpe(struct acpi_ec *ec) +{ + if (!test_bit(EC_FLAGS_GPE_MASKED, &ec->flags)) { + acpi_ec_disable_gpe(ec, false); + ec_dbg_drv("Polling enabled"); + set_bit(EC_FLAGS_GPE_MASKED, &ec->flags); + } +} + +static void acpi_ec_unmask_gpe(struct acpi_ec *ec) +{ + if (test_bit(EC_FLAGS_GPE_MASKED, &ec->flags)) { + clear_bit(EC_FLAGS_GPE_MASKED, &ec->flags); + acpi_ec_enable_gpe(ec, false); + ec_dbg_drv("Polling disabled"); + } +} + +/* + * acpi_ec_submit_flushable_request() - Increase the reference count unless + * the flush operation is not in + * progress + * @ec: the EC device + * + * This function must be used before taking a new action that should hold + * the reference count. If this function returns false, then the action + * must be discarded or it will prevent the flush operation from being + * completed. + */ +static bool acpi_ec_submit_flushable_request(struct acpi_ec *ec) +{ + if (!acpi_ec_started(ec)) + return false; + acpi_ec_submit_request(ec); + return true; +} + +static void acpi_ec_submit_query(struct acpi_ec *ec) +{ + acpi_ec_mask_gpe(ec); + if (!acpi_ec_event_enabled(ec)) + return; + if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) { + ec_dbg_evt("Command(%s) submitted/blocked", + acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY)); + ec->nr_pending_queries++; + schedule_work(&ec->work); + } +} + +static void acpi_ec_complete_query(struct acpi_ec *ec) +{ + if (test_and_clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) + ec_dbg_evt("Command(%s) unblocked", + acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY)); + acpi_ec_unmask_gpe(ec); +} + +static inline void __acpi_ec_enable_event(struct acpi_ec *ec) +{ + if (!test_and_set_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags)) + ec_log_drv("event unblocked"); + /* + * Unconditionally invoke this once after enabling the event + * handling mechanism to detect the pending events. + */ + advance_transaction(ec); +} + +static inline void __acpi_ec_disable_event(struct acpi_ec *ec) +{ + if (test_and_clear_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags)) + ec_log_drv("event blocked"); +} + +/* + * Process _Q events that might have accumulated in the EC. + * Run with locked ec mutex. + */ +static void acpi_ec_clear(struct acpi_ec *ec) +{ + int i, status; + u8 value = 0; + + for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) { + status = acpi_ec_query(ec, &value); + if (status || !value) + break; + } + if (unlikely(i == ACPI_EC_CLEAR_MAX)) + pr_warn("Warning: Maximum of %d stale EC events cleared\n", i); + else + pr_info("%d stale EC events cleared\n", i); +} + +static void acpi_ec_enable_event(struct acpi_ec *ec) +{ + unsigned long flags; + + spin_lock_irqsave(&ec->lock, flags); + if (acpi_ec_started(ec)) + __acpi_ec_enable_event(ec); + spin_unlock_irqrestore(&ec->lock, flags); + + /* Drain additional events if hardware requires that */ + if (EC_FLAGS_CLEAR_ON_RESUME) + acpi_ec_clear(ec); +} + +#ifdef CONFIG_PM_SLEEP +static bool acpi_ec_query_flushed(struct acpi_ec *ec) +{ + bool flushed; + unsigned long flags; + + spin_lock_irqsave(&ec->lock, flags); + flushed = !ec->nr_pending_queries; + spin_unlock_irqrestore(&ec->lock, flags); + return flushed; +} + +static void __acpi_ec_flush_event(struct acpi_ec *ec) +{ + /* + * When ec_freeze_events is true, we need to flush events in + * the proper position before entering the noirq stage. + */ + wait_event(ec->wait, acpi_ec_query_flushed(ec)); + if (ec_query_wq) + flush_workqueue(ec_query_wq); +} + +static void acpi_ec_disable_event(struct acpi_ec *ec) +{ + unsigned long flags; + + spin_lock_irqsave(&ec->lock, flags); + __acpi_ec_disable_event(ec); + spin_unlock_irqrestore(&ec->lock, flags); + __acpi_ec_flush_event(ec); +} + +void acpi_ec_flush_work(void) +{ + if (first_ec) + __acpi_ec_flush_event(first_ec); + + flush_scheduled_work(); +} +#endif /* CONFIG_PM_SLEEP */ + +static bool acpi_ec_guard_event(struct acpi_ec *ec) +{ + bool guarded = true; + unsigned long flags; + + spin_lock_irqsave(&ec->lock, flags); + /* + * If firmware SCI_EVT clearing timing is "event", we actually + * don't know when the SCI_EVT will be cleared by firmware after + * evaluating _Qxx, so we need to re-check SCI_EVT after waiting an + * acceptable period. + * + * The guarding period begins when EC_FLAGS_QUERY_PENDING is + * flagged, which means SCI_EVT check has just been performed. + * But if the current transaction is ACPI_EC_COMMAND_QUERY, the + * guarding should have already been performed (via + * EC_FLAGS_QUERY_GUARDING) and should not be applied so that the + * ACPI_EC_COMMAND_QUERY transaction can be transitioned into + * ACPI_EC_COMMAND_POLL state immediately. + */ + if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS || + ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY || + !test_bit(EC_FLAGS_QUERY_PENDING, &ec->flags) || + (ec->curr && ec->curr->command == ACPI_EC_COMMAND_QUERY)) + guarded = false; + spin_unlock_irqrestore(&ec->lock, flags); + return guarded; +} + +static int ec_transaction_polled(struct acpi_ec *ec) +{ + unsigned long flags; + int ret = 0; + + spin_lock_irqsave(&ec->lock, flags); + if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_POLL)) + ret = 1; + spin_unlock_irqrestore(&ec->lock, flags); + return ret; +} + +static int ec_transaction_completed(struct acpi_ec *ec) +{ + unsigned long flags; + int ret = 0; + + spin_lock_irqsave(&ec->lock, flags); + if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE)) + ret = 1; + spin_unlock_irqrestore(&ec->lock, flags); + return ret; +} + +static inline void ec_transaction_transition(struct acpi_ec *ec, unsigned long flag) +{ + ec->curr->flags |= flag; + if (ec->curr->command == ACPI_EC_COMMAND_QUERY) { + if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS && + flag == ACPI_EC_COMMAND_POLL) + acpi_ec_complete_query(ec); + if (ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY && + flag == ACPI_EC_COMMAND_COMPLETE) + acpi_ec_complete_query(ec); + if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT && + flag == ACPI_EC_COMMAND_COMPLETE) + set_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags); + } +} + +static void advance_transaction(struct acpi_ec *ec) +{ + struct transaction *t; + u8 status; + bool wakeup = false; + + ec_dbg_stm("%s (%d)", in_interrupt() ? "IRQ" : "TASK", + smp_processor_id()); + /* + * By always clearing STS before handling all indications, we can + * ensure a hardware STS 0->1 change after this clearing can always + * trigger a GPE interrupt. + */ + acpi_ec_clear_gpe(ec); + status = acpi_ec_read_status(ec); + t = ec->curr; + /* + * Another IRQ or a guarded polling mode advancement is detected, + * the next QR_EC submission is then allowed. + */ + if (!t || !(t->flags & ACPI_EC_COMMAND_POLL)) { + if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT && + (!ec->nr_pending_queries || + test_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags))) { + clear_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags); + acpi_ec_complete_query(ec); + } + } + if (!t) + goto err; + if (t->flags & ACPI_EC_COMMAND_POLL) { + if (t->wlen > t->wi) { + if ((status & ACPI_EC_FLAG_IBF) == 0) + acpi_ec_write_data(ec, t->wdata[t->wi++]); + else + goto err; + } else if (t->rlen > t->ri) { + if ((status & ACPI_EC_FLAG_OBF) == 1) { + t->rdata[t->ri++] = acpi_ec_read_data(ec); + if (t->rlen == t->ri) { + ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE); + if (t->command == ACPI_EC_COMMAND_QUERY) + ec_dbg_evt("Command(%s) completed by hardware", + acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY)); + wakeup = true; + } + } else + goto err; + } else if (t->wlen == t->wi && + (status & ACPI_EC_FLAG_IBF) == 0) { + ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE); + wakeup = true; + } + goto out; + } else { + if (EC_FLAGS_QUERY_HANDSHAKE && + !(status & ACPI_EC_FLAG_SCI) && + (t->command == ACPI_EC_COMMAND_QUERY)) { + ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL); + t->rdata[t->ri++] = 0x00; + ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE); + ec_dbg_evt("Command(%s) completed by software", + acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY)); + wakeup = true; + } else if ((status & ACPI_EC_FLAG_IBF) == 0) { + acpi_ec_write_cmd(ec, t->command); + ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL); + } else + goto err; + goto out; + } +err: + /* + * If SCI bit is set, then don't think it's a false IRQ + * otherwise will take a not handled IRQ as a false one. + */ + if (!(status & ACPI_EC_FLAG_SCI)) { + if (in_interrupt() && t) { + if (t->irq_count < ec_storm_threshold) + ++t->irq_count; + /* Allow triggering on 0 threshold */ + if (t->irq_count == ec_storm_threshold) + acpi_ec_mask_gpe(ec); + } + } +out: + if (status & ACPI_EC_FLAG_SCI) + acpi_ec_submit_query(ec); + if (wakeup && in_interrupt()) + wake_up(&ec->wait); +} + +static void start_transaction(struct acpi_ec *ec) +{ + ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0; + ec->curr->flags = 0; +} + +static int ec_guard(struct acpi_ec *ec) +{ + unsigned long guard = usecs_to_jiffies(ec->polling_guard); + unsigned long timeout = ec->timestamp + guard; + + /* Ensure guarding period before polling EC status */ + do { + if (ec->busy_polling) { + /* Perform busy polling */ + if (ec_transaction_completed(ec)) + return 0; + udelay(jiffies_to_usecs(guard)); + } else { + /* + * Perform wait polling + * 1. Wait the transaction to be completed by the + * GPE handler after the transaction enters + * ACPI_EC_COMMAND_POLL state. + * 2. A special guarding logic is also required + * for event clearing mode "event" before the + * transaction enters ACPI_EC_COMMAND_POLL + * state. + */ + if (!ec_transaction_polled(ec) && + !acpi_ec_guard_event(ec)) + break; + if (wait_event_timeout(ec->wait, + ec_transaction_completed(ec), + guard)) + return 0; + } + } while (time_before(jiffies, timeout)); + return -ETIME; +} + +static int ec_poll(struct acpi_ec *ec) +{ + unsigned long flags; + int repeat = 5; /* number of command restarts */ + + while (repeat--) { + unsigned long delay = jiffies + + msecs_to_jiffies(ec_delay); + do { + if (!ec_guard(ec)) + return 0; + spin_lock_irqsave(&ec->lock, flags); + advance_transaction(ec); + spin_unlock_irqrestore(&ec->lock, flags); + } while (time_before(jiffies, delay)); + pr_debug("controller reset, restart transaction\n"); + spin_lock_irqsave(&ec->lock, flags); + start_transaction(ec); + spin_unlock_irqrestore(&ec->lock, flags); + } + return -ETIME; +} + +static int acpi_ec_transaction_unlocked(struct acpi_ec *ec, + struct transaction *t) +{ + unsigned long tmp; + int ret = 0; + + /* start transaction */ + spin_lock_irqsave(&ec->lock, tmp); + /* Enable GPE for command processing (IBF=0/OBF=1) */ + if (!acpi_ec_submit_flushable_request(ec)) { + ret = -EINVAL; + goto unlock; + } + ec_dbg_ref(ec, "Increase command"); + /* following two actions should be kept atomic */ + ec->curr = t; + ec_dbg_req("Command(%s) started", acpi_ec_cmd_string(t->command)); + start_transaction(ec); + spin_unlock_irqrestore(&ec->lock, tmp); + + ret = ec_poll(ec); + + spin_lock_irqsave(&ec->lock, tmp); + if (t->irq_count == ec_storm_threshold) + acpi_ec_unmask_gpe(ec); + ec_dbg_req("Command(%s) stopped", acpi_ec_cmd_string(t->command)); + ec->curr = NULL; + /* Disable GPE for command processing (IBF=0/OBF=1) */ + acpi_ec_complete_request(ec); + ec_dbg_ref(ec, "Decrease command"); +unlock: + spin_unlock_irqrestore(&ec->lock, tmp); + return ret; +} + +static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t) +{ + int status; + u32 glk; + + if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata)) + return -EINVAL; + if (t->rdata) + memset(t->rdata, 0, t->rlen); + + mutex_lock(&ec->mutex); + if (ec->global_lock) { + status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk); + if (ACPI_FAILURE(status)) { + status = -ENODEV; + goto unlock; + } + } + + status = acpi_ec_transaction_unlocked(ec, t); + + if (ec->global_lock) + acpi_release_global_lock(glk); +unlock: + mutex_unlock(&ec->mutex); + return status; +} + +static int acpi_ec_burst_enable(struct acpi_ec *ec) +{ + u8 d; + struct transaction t = {.command = ACPI_EC_BURST_ENABLE, + .wdata = NULL, .rdata = &d, + .wlen = 0, .rlen = 1}; + + return acpi_ec_transaction(ec, &t); +} + +static int acpi_ec_burst_disable(struct acpi_ec *ec) +{ + struct transaction t = {.command = ACPI_EC_BURST_DISABLE, + .wdata = NULL, .rdata = NULL, + .wlen = 0, .rlen = 0}; + + return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ? + acpi_ec_transaction(ec, &t) : 0; +} + +static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 *data) +{ + int result; + u8 d; + struct transaction t = {.command = ACPI_EC_COMMAND_READ, + .wdata = &address, .rdata = &d, + .wlen = 1, .rlen = 1}; + + result = acpi_ec_transaction(ec, &t); + *data = d; + return result; +} + +static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data) +{ + u8 wdata[2] = { address, data }; + struct transaction t = {.command = ACPI_EC_COMMAND_WRITE, + .wdata = wdata, .rdata = NULL, + .wlen = 2, .rlen = 0}; + + return acpi_ec_transaction(ec, &t); +} + +int ec_read(u8 addr, u8 *val) +{ + int err; + u8 temp_data; + + if (!first_ec) + return -ENODEV; + + err = acpi_ec_read(first_ec, addr, &temp_data); + + if (!err) { + *val = temp_data; + return 0; + } + return err; +} +EXPORT_SYMBOL(ec_read); + +int ec_write(u8 addr, u8 val) +{ + int err; + + if (!first_ec) + return -ENODEV; + + err = acpi_ec_write(first_ec, addr, val); + + return err; +} +EXPORT_SYMBOL(ec_write); + +int ec_transaction(u8 command, + const u8 *wdata, unsigned wdata_len, + u8 *rdata, unsigned rdata_len) +{ + struct transaction t = {.command = command, + .wdata = wdata, .rdata = rdata, + .wlen = wdata_len, .rlen = rdata_len}; + + if (!first_ec) + return -ENODEV; + + return acpi_ec_transaction(first_ec, &t); +} +EXPORT_SYMBOL(ec_transaction); + +/* Get the handle to the EC device */ +acpi_handle ec_get_handle(void) +{ + if (!first_ec) + return NULL; + return first_ec->handle; +} +EXPORT_SYMBOL(ec_get_handle); + +static void acpi_ec_start(struct acpi_ec *ec, bool resuming) +{ + unsigned long flags; + + spin_lock_irqsave(&ec->lock, flags); + if (!test_and_set_bit(EC_FLAGS_STARTED, &ec->flags)) { + ec_dbg_drv("Starting EC"); + /* Enable GPE for event processing (SCI_EVT=1) */ + if (!resuming) { + acpi_ec_submit_request(ec); + ec_dbg_ref(ec, "Increase driver"); + } + ec_log_drv("EC started"); + } + spin_unlock_irqrestore(&ec->lock, flags); +} + +static bool acpi_ec_stopped(struct acpi_ec *ec) +{ + unsigned long flags; + bool flushed; + + spin_lock_irqsave(&ec->lock, flags); + flushed = acpi_ec_flushed(ec); + spin_unlock_irqrestore(&ec->lock, flags); + return flushed; +} + +static void acpi_ec_stop(struct acpi_ec *ec, bool suspending) +{ + unsigned long flags; + + spin_lock_irqsave(&ec->lock, flags); + if (acpi_ec_started(ec)) { + ec_dbg_drv("Stopping EC"); + set_bit(EC_FLAGS_STOPPED, &ec->flags); + spin_unlock_irqrestore(&ec->lock, flags); + wait_event(ec->wait, acpi_ec_stopped(ec)); + spin_lock_irqsave(&ec->lock, flags); + /* Disable GPE for event processing (SCI_EVT=1) */ + if (!suspending) { + acpi_ec_complete_request(ec); + ec_dbg_ref(ec, "Decrease driver"); + } else if (!ec_freeze_events) + __acpi_ec_disable_event(ec); + clear_bit(EC_FLAGS_STARTED, &ec->flags); + clear_bit(EC_FLAGS_STOPPED, &ec->flags); + ec_log_drv("EC stopped"); + } + spin_unlock_irqrestore(&ec->lock, flags); +} + +static void acpi_ec_enter_noirq(struct acpi_ec *ec) +{ + unsigned long flags; + + spin_lock_irqsave(&ec->lock, flags); + ec->busy_polling = true; + ec->polling_guard = 0; + ec_log_drv("interrupt blocked"); + spin_unlock_irqrestore(&ec->lock, flags); +} + +static void acpi_ec_leave_noirq(struct acpi_ec *ec) +{ + unsigned long flags; + + spin_lock_irqsave(&ec->lock, flags); + ec->busy_polling = ec_busy_polling; + ec->polling_guard = ec_polling_guard; + ec_log_drv("interrupt unblocked"); + spin_unlock_irqrestore(&ec->lock, flags); +} + +void acpi_ec_block_transactions(void) +{ + struct acpi_ec *ec = first_ec; + + if (!ec) + return; + + mutex_lock(&ec->mutex); + /* Prevent transactions from being carried out */ + acpi_ec_stop(ec, true); + mutex_unlock(&ec->mutex); +} + +void acpi_ec_unblock_transactions(void) +{ + /* + * Allow transactions to happen again (this function is called from + * atomic context during wakeup, so we don't need to acquire the mutex). + */ + if (first_ec) + acpi_ec_start(first_ec, true); +} + +void acpi_ec_mark_gpe_for_wake(void) +{ + if (first_ec && !ec_no_wakeup) + acpi_mark_gpe_for_wake(NULL, first_ec->gpe); +} + +void acpi_ec_set_gpe_wake_mask(u8 action) +{ + if (first_ec && !ec_no_wakeup) + acpi_set_gpe_wake_mask(NULL, first_ec->gpe, action); +} + +void acpi_ec_dispatch_gpe(void) +{ + if (first_ec) + acpi_dispatch_gpe(NULL, first_ec->gpe); +} + +/* -------------------------------------------------------------------------- + Event Management + -------------------------------------------------------------------------- */ +static struct acpi_ec_query_handler * +acpi_ec_get_query_handler_by_value(struct acpi_ec *ec, u8 value) +{ + struct acpi_ec_query_handler *handler; + + mutex_lock(&ec->mutex); + list_for_each_entry(handler, &ec->list, node) { + if (value == handler->query_bit) { + kref_get(&handler->kref); + mutex_unlock(&ec->mutex); + return handler; + } + } + mutex_unlock(&ec->mutex); + return NULL; +} + +static void acpi_ec_query_handler_release(struct kref *kref) +{ + struct acpi_ec_query_handler *handler = + container_of(kref, struct acpi_ec_query_handler, kref); + + kfree(handler); +} + +static void acpi_ec_put_query_handler(struct acpi_ec_query_handler *handler) +{ + kref_put(&handler->kref, acpi_ec_query_handler_release); +} + +int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit, + acpi_handle handle, acpi_ec_query_func func, + void *data) +{ + struct acpi_ec_query_handler *handler = + kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL); + + if (!handler) + return -ENOMEM; + + handler->query_bit = query_bit; + handler->handle = handle; + handler->func = func; + handler->data = data; + mutex_lock(&ec->mutex); + kref_init(&handler->kref); + list_add(&handler->node, &ec->list); + mutex_unlock(&ec->mutex); + return 0; +} +EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler); + +static void acpi_ec_remove_query_handlers(struct acpi_ec *ec, + bool remove_all, u8 query_bit) +{ + struct acpi_ec_query_handler *handler, *tmp; + LIST_HEAD(free_list); + + mutex_lock(&ec->mutex); + list_for_each_entry_safe(handler, tmp, &ec->list, node) { + if (remove_all || query_bit == handler->query_bit) { + list_del_init(&handler->node); + list_add(&handler->node, &free_list); + } + } + mutex_unlock(&ec->mutex); + list_for_each_entry_safe(handler, tmp, &free_list, node) + acpi_ec_put_query_handler(handler); +} + +void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit) +{ + acpi_ec_remove_query_handlers(ec, false, query_bit); +} +EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler); + +static struct acpi_ec_query *acpi_ec_create_query(u8 *pval) +{ + struct acpi_ec_query *q; + struct transaction *t; + + q = kzalloc(sizeof (struct acpi_ec_query), GFP_KERNEL); + if (!q) + return NULL; + INIT_WORK(&q->work, acpi_ec_event_processor); + t = &q->transaction; + t->command = ACPI_EC_COMMAND_QUERY; + t->rdata = pval; + t->rlen = 1; + return q; +} + +static void acpi_ec_delete_query(struct acpi_ec_query *q) +{ + if (q) { + if (q->handler) + acpi_ec_put_query_handler(q->handler); + kfree(q); + } +} + +static void acpi_ec_event_processor(struct work_struct *work) +{ + struct acpi_ec_query *q = container_of(work, struct acpi_ec_query, work); + struct acpi_ec_query_handler *handler = q->handler; + + ec_dbg_evt("Query(0x%02x) started", handler->query_bit); + if (handler->func) + handler->func(handler->data); + else if (handler->handle) + acpi_evaluate_object(handler->handle, NULL, NULL, NULL); + ec_dbg_evt("Query(0x%02x) stopped", handler->query_bit); + acpi_ec_delete_query(q); +} + +static int acpi_ec_query(struct acpi_ec *ec, u8 *data) +{ + u8 value = 0; + int result; + struct acpi_ec_query *q; + + q = acpi_ec_create_query(&value); + if (!q) + return -ENOMEM; + + /* + * Query the EC to find out which _Qxx method we need to evaluate. + * Note that successful completion of the query causes the ACPI_EC_SCI + * bit to be cleared (and thus clearing the interrupt source). + */ + result = acpi_ec_transaction(ec, &q->transaction); + if (!value) + result = -ENODATA; + if (result) + goto err_exit; + + q->handler = acpi_ec_get_query_handler_by_value(ec, value); + if (!q->handler) { + result = -ENODATA; + goto err_exit; + } + + /* + * It is reported that _Qxx are evaluated in a parallel way on + * Windows: + * https://bugzilla.kernel.org/show_bug.cgi?id=94411 + * + * Put this log entry before schedule_work() in order to make + * it appearing before any other log entries occurred during the + * work queue execution. + */ + ec_dbg_evt("Query(0x%02x) scheduled", value); + if (!queue_work(ec_query_wq, &q->work)) { + ec_dbg_evt("Query(0x%02x) overlapped", value); + result = -EBUSY; + } + +err_exit: + if (result) + acpi_ec_delete_query(q); + if (data) + *data = value; + return result; +} + +static void acpi_ec_check_event(struct acpi_ec *ec) +{ + unsigned long flags; + + if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT) { + if (ec_guard(ec)) { + spin_lock_irqsave(&ec->lock, flags); + /* + * Take care of the SCI_EVT unless no one else is + * taking care of it. + */ + if (!ec->curr) + advance_transaction(ec); + spin_unlock_irqrestore(&ec->lock, flags); + } + } +} + +static void acpi_ec_event_handler(struct work_struct *work) +{ + unsigned long flags; + struct acpi_ec *ec = container_of(work, struct acpi_ec, work); + + ec_dbg_evt("Event started"); + + spin_lock_irqsave(&ec->lock, flags); + while (ec->nr_pending_queries) { + spin_unlock_irqrestore(&ec->lock, flags); + (void)acpi_ec_query(ec, NULL); + spin_lock_irqsave(&ec->lock, flags); + ec->nr_pending_queries--; + /* + * Before exit, make sure that this work item can be + * scheduled again. There might be QR_EC failures, leaving + * EC_FLAGS_QUERY_PENDING uncleared and preventing this work + * item from being scheduled again. + */ + if (!ec->nr_pending_queries) { + if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS || + ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY) + acpi_ec_complete_query(ec); + } + } + spin_unlock_irqrestore(&ec->lock, flags); + + ec_dbg_evt("Event stopped"); + + acpi_ec_check_event(ec); +} + +static u32 acpi_ec_gpe_handler(acpi_handle gpe_device, + u32 gpe_number, void *data) +{ + unsigned long flags; + struct acpi_ec *ec = data; + + spin_lock_irqsave(&ec->lock, flags); + advance_transaction(ec); + spin_unlock_irqrestore(&ec->lock, flags); + return ACPI_INTERRUPT_HANDLED; +} + +/* -------------------------------------------------------------------------- + * Address Space Management + * -------------------------------------------------------------------------- */ + +static acpi_status +acpi_ec_space_handler(u32 function, acpi_physical_address address, + u32 bits, u64 *value64, + void *handler_context, void *region_context) +{ + struct acpi_ec *ec = handler_context; + int result = 0, i, bytes = bits / 8; + u8 *value = (u8 *)value64; + + if ((address > 0xFF) || !value || !handler_context) + return AE_BAD_PARAMETER; + + if (function != ACPI_READ && function != ACPI_WRITE) + return AE_BAD_PARAMETER; + + if (ec->busy_polling || bits > 8) + acpi_ec_burst_enable(ec); + + for (i = 0; i < bytes; ++i, ++address, ++value) + result = (function == ACPI_READ) ? + acpi_ec_read(ec, address, value) : + acpi_ec_write(ec, address, *value); + + if (ec->busy_polling || bits > 8) + acpi_ec_burst_disable(ec); + + switch (result) { + case -EINVAL: + return AE_BAD_PARAMETER; + case -ENODEV: + return AE_NOT_FOUND; + case -ETIME: + return AE_TIME; + default: + return AE_OK; + } +} + +/* -------------------------------------------------------------------------- + * Driver Interface + * -------------------------------------------------------------------------- */ + +static acpi_status +ec_parse_io_ports(struct acpi_resource *resource, void *context); + +static void acpi_ec_free(struct acpi_ec *ec) +{ + if (first_ec == ec) + first_ec = NULL; + if (boot_ec == ec) + boot_ec = NULL; + kfree(ec); +} + +static struct acpi_ec *acpi_ec_alloc(void) +{ + struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL); + + if (!ec) + return NULL; + mutex_init(&ec->mutex); + init_waitqueue_head(&ec->wait); + INIT_LIST_HEAD(&ec->list); + spin_lock_init(&ec->lock); + INIT_WORK(&ec->work, acpi_ec_event_handler); + ec->timestamp = jiffies; + ec->busy_polling = true; + ec->polling_guard = 0; + return ec; +} + +static acpi_status +acpi_ec_register_query_methods(acpi_handle handle, u32 level, + void *context, void **return_value) +{ + char node_name[5]; + struct acpi_buffer buffer = { sizeof(node_name), node_name }; + struct acpi_ec *ec = context; + int value = 0; + acpi_status status; + + status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer); + + if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) + acpi_ec_add_query_handler(ec, value, handle, NULL, NULL); + return AE_OK; +} + +static acpi_status +ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval) +{ + acpi_status status; + unsigned long long tmp = 0; + struct acpi_ec *ec = context; + + /* clear addr values, ec_parse_io_ports depend on it */ + ec->command_addr = ec->data_addr = 0; + + status = acpi_walk_resources(handle, METHOD_NAME__CRS, + ec_parse_io_ports, ec); + if (ACPI_FAILURE(status)) + return status; + if (ec->data_addr == 0 || ec->command_addr == 0) + return AE_OK; + + if (boot_ec && boot_ec_is_ecdt && EC_FLAGS_IGNORE_DSDT_GPE) { + /* + * Always inherit the GPE number setting from the ECDT + * EC. + */ + ec->gpe = boot_ec->gpe; + } else { + /* Get GPE bit assignment (EC events). */ + /* TODO: Add support for _GPE returning a package */ + status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp); + if (ACPI_FAILURE(status)) + return status; + ec->gpe = tmp; + } + /* Use the global lock for all EC transactions? */ + tmp = 0; + acpi_evaluate_integer(handle, "_GLK", NULL, &tmp); + ec->global_lock = tmp; + ec->handle = handle; + return AE_CTRL_TERMINATE; +} + +/* + * Note: This function returns an error code only when the address space + * handler is not installed, which means "not able to handle + * transactions". + */ +static int ec_install_handlers(struct acpi_ec *ec, bool handle_events) +{ + acpi_status status; + + acpi_ec_start(ec, false); + + if (!test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) { + acpi_ec_enter_noirq(ec); + status = acpi_install_address_space_handler(ec->handle, + ACPI_ADR_SPACE_EC, + &acpi_ec_space_handler, + NULL, ec); + if (ACPI_FAILURE(status)) { + if (status == AE_NOT_FOUND) { + /* + * Maybe OS fails in evaluating the _REG + * object. The AE_NOT_FOUND error will be + * ignored and OS * continue to initialize + * EC. + */ + pr_err("Fail in evaluating the _REG object" + " of EC device. Broken bios is suspected.\n"); + } else { + acpi_ec_stop(ec, false); + return -ENODEV; + } + } + set_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags); + } + + if (!handle_events) + return 0; + + if (!test_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags)) { + /* Find and register all query methods */ + acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1, + acpi_ec_register_query_methods, + NULL, ec, NULL); + set_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags); + } + if (!test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags)) { + status = acpi_install_gpe_raw_handler(NULL, ec->gpe, + ACPI_GPE_EDGE_TRIGGERED, + &acpi_ec_gpe_handler, ec); + /* This is not fatal as we can poll EC events */ + if (ACPI_SUCCESS(status)) { + set_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags); + acpi_ec_leave_noirq(ec); + if (test_bit(EC_FLAGS_STARTED, &ec->flags) && + ec->reference_count >= 1) + acpi_ec_enable_gpe(ec, true); + } + } + /* EC is fully operational, allow queries */ + acpi_ec_enable_event(ec); + + return 0; +} + +static void ec_remove_handlers(struct acpi_ec *ec) +{ + if (test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) { + if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle, + ACPI_ADR_SPACE_EC, &acpi_ec_space_handler))) + pr_err("failed to remove space handler\n"); + clear_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags); + } + + /* + * Stops handling the EC transactions after removing the operation + * region handler. This is required because _REG(DISCONNECT) + * invoked during the removal can result in new EC transactions. + * + * Flushes the EC requests and thus disables the GPE before + * removing the GPE handler. This is required by the current ACPICA + * GPE core. ACPICA GPE core will automatically disable a GPE when + * it is indicated but there is no way to handle it. So the drivers + * must disable the GPEs prior to removing the GPE handlers. + */ + acpi_ec_stop(ec, false); + + if (test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags)) { + if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe, + &acpi_ec_gpe_handler))) + pr_err("failed to remove gpe handler\n"); + clear_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags); + } + if (test_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags)) { + acpi_ec_remove_query_handlers(ec, true, 0); + clear_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags); + } +} + +static int acpi_ec_setup(struct acpi_ec *ec, bool handle_events) +{ + int ret; + + ret = ec_install_handlers(ec, handle_events); + if (ret) + return ret; + + /* First EC capable of handling transactions */ + if (!first_ec) { + first_ec = ec; + acpi_handle_info(first_ec->handle, "Used as first EC\n"); + } + + acpi_handle_info(ec->handle, + "GPE=0x%x, EC_CMD/EC_SC=0x%lx, EC_DATA=0x%lx\n", + ec->gpe, ec->command_addr, ec->data_addr); + return ret; +} + +static int acpi_config_boot_ec(struct acpi_ec *ec, acpi_handle handle, + bool handle_events, bool is_ecdt) +{ + int ret; + + /* + * Changing the ACPI handle results in a re-configuration of the + * boot EC. And if it happens after the namespace initialization, + * it causes _REG evaluations. + */ + if (boot_ec && boot_ec->handle != handle) + ec_remove_handlers(boot_ec); + + /* Unset old boot EC */ + if (boot_ec != ec) + acpi_ec_free(boot_ec); + + /* + * ECDT device creation is split into acpi_ec_ecdt_probe() and + * acpi_ec_ecdt_start(). This function takes care of completing the + * ECDT parsing logic as the handle update should be performed + * between the installation/uninstallation of the handlers. + */ + if (ec->handle != handle) + ec->handle = handle; + + ret = acpi_ec_setup(ec, handle_events); + if (ret) + return ret; + + /* Set new boot EC */ + if (!boot_ec) { + boot_ec = ec; + boot_ec_is_ecdt = is_ecdt; + } + + acpi_handle_info(boot_ec->handle, + "Used as boot %s EC to handle transactions%s\n", + is_ecdt ? "ECDT" : "DSDT", + handle_events ? " and events" : ""); + return ret; +} + +static bool acpi_ec_ecdt_get_handle(acpi_handle *phandle) +{ + struct acpi_table_ecdt *ecdt_ptr; + acpi_status status; + acpi_handle handle; + + status = acpi_get_table(ACPI_SIG_ECDT, 1, + (struct acpi_table_header **)&ecdt_ptr); + if (ACPI_FAILURE(status)) + return false; + + status = acpi_get_handle(NULL, ecdt_ptr->id, &handle); + if (ACPI_FAILURE(status)) + return false; + + *phandle = handle; + return true; +} + +static bool acpi_is_boot_ec(struct acpi_ec *ec) +{ + if (!boot_ec) + return false; + if (ec->command_addr == boot_ec->command_addr && + ec->data_addr == boot_ec->data_addr) + return true; + return false; +} + +static int acpi_ec_add(struct acpi_device *device) +{ + struct acpi_ec *ec = NULL; + int ret; + bool is_ecdt = false; + acpi_status status; + + strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME); + strcpy(acpi_device_class(device), ACPI_EC_CLASS); + + if (!strcmp(acpi_device_hid(device), ACPI_ECDT_HID)) { + is_ecdt = true; + ec = boot_ec; + } else { + ec = acpi_ec_alloc(); + if (!ec) + return -ENOMEM; + status = ec_parse_device(device->handle, 0, ec, NULL); + if (status != AE_CTRL_TERMINATE) { + ret = -EINVAL; + goto err_alloc; + } + } + + if (acpi_is_boot_ec(ec)) { + boot_ec_is_ecdt = is_ecdt; + if (!is_ecdt) { + /* + * Trust PNP0C09 namespace location rather than + * ECDT ID. But trust ECDT GPE rather than _GPE + * because of ASUS quirks, so do not change + * boot_ec->gpe to ec->gpe. + */ + boot_ec->handle = ec->handle; + acpi_handle_debug(ec->handle, "duplicated.\n"); + acpi_ec_free(ec); + ec = boot_ec; + } + ret = acpi_config_boot_ec(ec, ec->handle, true, is_ecdt); + } else + ret = acpi_ec_setup(ec, true); + if (ret) + goto err_query; + + device->driver_data = ec; + + ret = !!request_region(ec->data_addr, 1, "EC data"); + WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr); + ret = !!request_region(ec->command_addr, 1, "EC cmd"); + WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr); + + if (!is_ecdt) { + /* Reprobe devices depending on the EC */ + acpi_walk_dep_device_list(ec->handle); + } + acpi_handle_debug(ec->handle, "enumerated.\n"); + return 0; + +err_query: + if (ec != boot_ec) + acpi_ec_remove_query_handlers(ec, true, 0); +err_alloc: + if (ec != boot_ec) + acpi_ec_free(ec); + return ret; +} + +static int acpi_ec_remove(struct acpi_device *device) +{ + struct acpi_ec *ec; + + if (!device) + return -EINVAL; + + ec = acpi_driver_data(device); + release_region(ec->data_addr, 1); + release_region(ec->command_addr, 1); + device->driver_data = NULL; + if (ec != boot_ec) { + ec_remove_handlers(ec); + acpi_ec_free(ec); + } + return 0; +} + +static acpi_status +ec_parse_io_ports(struct acpi_resource *resource, void *context) +{ + struct acpi_ec *ec = context; + + if (resource->type != ACPI_RESOURCE_TYPE_IO) + return AE_OK; + + /* + * The first address region returned is the data port, and + * the second address region returned is the status/command + * port. + */ + if (ec->data_addr == 0) + ec->data_addr = resource->data.io.minimum; + else if (ec->command_addr == 0) + ec->command_addr = resource->data.io.minimum; + else + return AE_CTRL_TERMINATE; + + return AE_OK; +} + +static const struct acpi_device_id ec_device_ids[] = { + {"PNP0C09", 0}, + {ACPI_ECDT_HID, 0}, + {"", 0}, +}; + +/* + * This function is not Windows-compatible as Windows never enumerates the + * namespace EC before the main ACPI device enumeration process. It is + * retained for historical reason and will be deprecated in the future. + */ +int __init acpi_ec_dsdt_probe(void) +{ + acpi_status status; + struct acpi_ec *ec; + int ret; + + /* + * If a platform has ECDT, there is no need to proceed as the + * following probe is not a part of the ACPI device enumeration, + * executing _STA is not safe, and thus this probe may risk of + * picking up an invalid EC device. + */ + if (boot_ec) + return -ENODEV; + + ec = acpi_ec_alloc(); + if (!ec) + return -ENOMEM; + /* + * At this point, the namespace is initialized, so start to find + * the namespace objects. + */ + status = acpi_get_devices(ec_device_ids[0].id, + ec_parse_device, ec, NULL); + if (ACPI_FAILURE(status) || !ec->handle) { + ret = -ENODEV; + goto error; + } + /* + * When the DSDT EC is available, always re-configure boot EC to + * have _REG evaluated. _REG can only be evaluated after the + * namespace initialization. + * At this point, the GPE is not fully initialized, so do not to + * handle the events. + */ + ret = acpi_config_boot_ec(ec, ec->handle, false, false); +error: + if (ret) + acpi_ec_free(ec); + return ret; +} + +/* + * If the DSDT EC is not functioning, we still need to prepare a fully + * functioning ECDT EC first in order to handle the events. + * https://bugzilla.kernel.org/show_bug.cgi?id=115021 + */ +static int __init acpi_ec_ecdt_start(void) +{ + acpi_handle handle; + + if (!boot_ec) + return -ENODEV; + /* In case acpi_ec_ecdt_start() is called after acpi_ec_add() */ + if (!boot_ec_is_ecdt) + return -ENODEV; + + /* + * At this point, the namespace and the GPE is initialized, so + * start to find the namespace objects and handle the events. + * + * Note: ec->handle can be valid if this function is called after + * acpi_ec_add(), hence the fast path. + */ + if (boot_ec->handle == ACPI_ROOT_OBJECT) { + if (!acpi_ec_ecdt_get_handle(&handle)) + return -ENODEV; + boot_ec->handle = handle; + } + + /* Register to ACPI bus with PM ops attached */ + return acpi_bus_register_early_device(ACPI_BUS_TYPE_ECDT_EC); +} + +#if 0 +/* + * Some EC firmware variations refuses to respond QR_EC when SCI_EVT is not + * set, for which case, we complete the QR_EC without issuing it to the + * firmware. + * https://bugzilla.kernel.org/show_bug.cgi?id=82611 + * https://bugzilla.kernel.org/show_bug.cgi?id=97381 + */ +static int ec_flag_query_handshake(const struct dmi_system_id *id) +{ + pr_debug("Detected the EC firmware requiring QR_EC issued when SCI_EVT set\n"); + EC_FLAGS_QUERY_HANDSHAKE = 1; + return 0; +} +#endif + +/* + * On some hardware it is necessary to clear events accumulated by the EC during + * sleep. These ECs stop reporting GPEs until they are manually polled, if too + * many events are accumulated. (e.g. Samsung Series 5/9 notebooks) + * + * https://bugzilla.kernel.org/show_bug.cgi?id=44161 + * + * Ideally, the EC should also be instructed NOT to accumulate events during + * sleep (which Windows seems to do somehow), but the interface to control this + * behaviour is not known at this time. + * + * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx, + * however it is very likely that other Samsung models are affected. + * + * On systems which don't accumulate _Q events during sleep, this extra check + * should be harmless. + */ +static int ec_clear_on_resume(const struct dmi_system_id *id) +{ + pr_debug("Detected system needing EC poll on resume.\n"); + EC_FLAGS_CLEAR_ON_RESUME = 1; + ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS; + return 0; +} + +/* + * Some ECDTs contain wrong register addresses. + * MSI MS-171F + * https://bugzilla.kernel.org/show_bug.cgi?id=12461 + */ +static int ec_correct_ecdt(const struct dmi_system_id *id) +{ + pr_debug("Detected system needing ECDT address correction.\n"); + EC_FLAGS_CORRECT_ECDT = 1; + return 0; +} + +/* + * Some DSDTs contain wrong GPE setting. + * Asus FX502VD/VE, GL702VMK, X550VXK, X580VD + * https://bugzilla.kernel.org/show_bug.cgi?id=195651 + */ +static int ec_honor_ecdt_gpe(const struct dmi_system_id *id) +{ + pr_debug("Detected system needing ignore DSDT GPE setting.\n"); + EC_FLAGS_IGNORE_DSDT_GPE = 1; + return 0; +} + +static const struct dmi_system_id ec_dmi_table[] __initconst = { + { + ec_correct_ecdt, "MSI MS-171F", { + DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star"), + DMI_MATCH(DMI_PRODUCT_NAME, "MS-171F"),}, NULL}, + { + ec_honor_ecdt_gpe, "ASUS FX502VD", { + DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."), + DMI_MATCH(DMI_PRODUCT_NAME, "FX502VD"),}, NULL}, + { + ec_honor_ecdt_gpe, "ASUS FX502VE", { + DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."), + DMI_MATCH(DMI_PRODUCT_NAME, "FX502VE"),}, NULL}, + { + ec_honor_ecdt_gpe, "ASUS GL702VMK", { + DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."), + DMI_MATCH(DMI_PRODUCT_NAME, "GL702VMK"),}, NULL}, + { + ec_honor_ecdt_gpe, "ASUSTeK COMPUTER INC. X505BA", { + DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."), + DMI_MATCH(DMI_PRODUCT_NAME, "X505BA"),}, NULL}, + { + ec_honor_ecdt_gpe, "ASUSTeK COMPUTER INC. X505BP", { + DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."), + DMI_MATCH(DMI_PRODUCT_NAME, "X505BP"),}, NULL}, + { + ec_honor_ecdt_gpe, "ASUSTeK COMPUTER INC. X542BA", { + DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."), + DMI_MATCH(DMI_PRODUCT_NAME, "X542BA"),}, NULL}, + { + ec_honor_ecdt_gpe, "ASUSTeK COMPUTER INC. X542BP", { + DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."), + DMI_MATCH(DMI_PRODUCT_NAME, "X542BP"),}, NULL}, + { + ec_honor_ecdt_gpe, "ASUS X550VXK", { + DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."), + DMI_MATCH(DMI_PRODUCT_NAME, "X550VXK"),}, NULL}, + { + ec_honor_ecdt_gpe, "ASUS X580VD", { + DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."), + DMI_MATCH(DMI_PRODUCT_NAME, "X580VD"),}, NULL}, + { + ec_clear_on_resume, "Samsung hardware", { + DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD.")}, NULL}, + {}, +}; + +int __init acpi_ec_ecdt_probe(void) +{ + int ret; + acpi_status status; + struct acpi_table_ecdt *ecdt_ptr; + struct acpi_ec *ec; + + ec = acpi_ec_alloc(); + if (!ec) + return -ENOMEM; + /* + * Generate a boot ec context + */ + dmi_check_system(ec_dmi_table); + status = acpi_get_table(ACPI_SIG_ECDT, 1, + (struct acpi_table_header **)&ecdt_ptr); + if (ACPI_FAILURE(status)) { + ret = -ENODEV; + goto error; + } + + if (!ecdt_ptr->control.address || !ecdt_ptr->data.address) { + /* + * Asus X50GL: + * https://bugzilla.kernel.org/show_bug.cgi?id=11880 + */ + ret = -ENODEV; + goto error; + } + + if (EC_FLAGS_CORRECT_ECDT) { + ec->command_addr = ecdt_ptr->data.address; + ec->data_addr = ecdt_ptr->control.address; + } else { + ec->command_addr = ecdt_ptr->control.address; + ec->data_addr = ecdt_ptr->data.address; + } + ec->gpe = ecdt_ptr->gpe; + + /* + * At this point, the namespace is not initialized, so do not find + * the namespace objects, or handle the events. + */ + ret = acpi_config_boot_ec(ec, ACPI_ROOT_OBJECT, false, true); +error: + if (ret) + acpi_ec_free(ec); + return ret; +} + +#ifdef CONFIG_PM_SLEEP +static int acpi_ec_suspend(struct device *dev) +{ + struct acpi_ec *ec = + acpi_driver_data(to_acpi_device(dev)); + + if (acpi_sleep_no_ec_events() && ec_freeze_events) + acpi_ec_disable_event(ec); + return 0; +} + +static int acpi_ec_suspend_noirq(struct device *dev) +{ + struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev)); + + /* + * The SCI handler doesn't run at this point, so the GPE can be + * masked at the low level without side effects. + */ + if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) && + ec->reference_count >= 1) + acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE); + + if (acpi_sleep_no_ec_events()) + acpi_ec_enter_noirq(ec); + + return 0; +} + +static int acpi_ec_resume_noirq(struct device *dev) +{ + struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev)); + + if (acpi_sleep_no_ec_events()) + acpi_ec_leave_noirq(ec); + + if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) && + ec->reference_count >= 1) + acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE); + + return 0; +} + +static int acpi_ec_resume(struct device *dev) +{ + struct acpi_ec *ec = + acpi_driver_data(to_acpi_device(dev)); + + acpi_ec_enable_event(ec); + return 0; +} +#endif + +static const struct dev_pm_ops acpi_ec_pm = { + SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend_noirq, acpi_ec_resume_noirq) + SET_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend, acpi_ec_resume) +}; + +static int param_set_event_clearing(const char *val, + const struct kernel_param *kp) +{ + int result = 0; + + if (!strncmp(val, "status", sizeof("status") - 1)) { + ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS; + pr_info("Assuming SCI_EVT clearing on EC_SC accesses\n"); + } else if (!strncmp(val, "query", sizeof("query") - 1)) { + ec_event_clearing = ACPI_EC_EVT_TIMING_QUERY; + pr_info("Assuming SCI_EVT clearing on QR_EC writes\n"); + } else if (!strncmp(val, "event", sizeof("event") - 1)) { + ec_event_clearing = ACPI_EC_EVT_TIMING_EVENT; + pr_info("Assuming SCI_EVT clearing on event reads\n"); + } else + result = -EINVAL; + return result; +} + +static int param_get_event_clearing(char *buffer, + const struct kernel_param *kp) +{ + switch (ec_event_clearing) { + case ACPI_EC_EVT_TIMING_STATUS: + return sprintf(buffer, "status"); + case ACPI_EC_EVT_TIMING_QUERY: + return sprintf(buffer, "query"); + case ACPI_EC_EVT_TIMING_EVENT: + return sprintf(buffer, "event"); + default: + return sprintf(buffer, "invalid"); + } + return 0; +} + +module_param_call(ec_event_clearing, param_set_event_clearing, param_get_event_clearing, + NULL, 0644); +MODULE_PARM_DESC(ec_event_clearing, "Assumed SCI_EVT clearing timing"); + +static struct acpi_driver acpi_ec_driver = { + .name = "ec", + .class = ACPI_EC_CLASS, + .ids = ec_device_ids, + .ops = { + .add = acpi_ec_add, + .remove = acpi_ec_remove, + }, + .drv.pm = &acpi_ec_pm, +}; + +static inline int acpi_ec_query_init(void) +{ + if (!ec_query_wq) { + ec_query_wq = alloc_workqueue("kec_query", 0, + ec_max_queries); + if (!ec_query_wq) + return -ENODEV; + } + return 0; +} + +static inline void acpi_ec_query_exit(void) +{ + if (ec_query_wq) { + destroy_workqueue(ec_query_wq); + ec_query_wq = NULL; + } +} + +static const struct dmi_system_id acpi_ec_no_wakeup[] = { + { + .ident = "Thinkpad X1 Carbon 6th", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"), + DMI_MATCH(DMI_PRODUCT_FAMILY, "Thinkpad X1 Carbon 6th"), + }, + }, + { + .ident = "ThinkPad X1 Carbon 6th", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"), + DMI_MATCH(DMI_PRODUCT_FAMILY, "ThinkPad X1 Carbon 6th"), + }, + }, + { + .ident = "ThinkPad X1 Yoga 3rd", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"), + DMI_MATCH(DMI_PRODUCT_FAMILY, "ThinkPad X1 Yoga 3rd"), + }, + }, + { }, +}; + +int __init acpi_ec_init(void) +{ + int result; + int ecdt_fail, dsdt_fail; + + /* register workqueue for _Qxx evaluations */ + result = acpi_ec_query_init(); + if (result) + return result; + + /* + * Disable EC wakeup on following systems to prevent periodic + * wakeup from EC GPE. + */ + if (dmi_check_system(acpi_ec_no_wakeup)) { + ec_no_wakeup = true; + pr_debug("Disabling EC wakeup on suspend-to-idle\n"); + } + + /* Drivers must be started after acpi_ec_query_init() */ + dsdt_fail = acpi_bus_register_driver(&acpi_ec_driver); + /* + * Register ECDT to ACPI bus only when PNP0C09 probe fails. This is + * useful for platforms (confirmed on ASUS X550ZE) with valid ECDT + * settings but invalid DSDT settings. + * https://bugzilla.kernel.org/show_bug.cgi?id=196847 + */ + ecdt_fail = acpi_ec_ecdt_start(); + return ecdt_fail && dsdt_fail ? -ENODEV : 0; +} + +/* EC driver currently not unloadable */ +#if 0 +static void __exit acpi_ec_exit(void) +{ + + acpi_bus_unregister_driver(&acpi_ec_driver); + acpi_ec_query_exit(); +} +#endif /* 0 */ |