--- /dev/null
+/*
+ * ACPI watchdog table parsing support.
+ *
+ * Copyright (C) 2016, Intel Corporation
+ * Author: Mika Westerberg <mika.westerberg@linux.intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#define pr_fmt(fmt) "ACPI: watchdog: " fmt
+
+#include <linux/acpi.h>
+#include <linux/ioport.h>
+#include <linux/platform_device.h>
+
+#include "internal.h"
+
+/**
+ * Returns true if this system should prefer ACPI based watchdog instead of
+ * the native one (which are typically the same hardware).
+ */
+bool acpi_has_watchdog(void)
+{
+ struct acpi_table_header hdr;
+
+ if (acpi_disabled)
+ return false;
+
+ return ACPI_SUCCESS(acpi_get_table_header(ACPI_SIG_WDAT, 0, &hdr));
+}
+EXPORT_SYMBOL_GPL(acpi_has_watchdog);
+
+void __init acpi_watchdog_init(void)
+{
+ const struct acpi_wdat_entry *entries;
+ const struct acpi_table_wdat *wdat;
+ struct list_head resource_list;
+ struct resource_entry *rentry;
+ struct platform_device *pdev;
+ struct resource *resources;
+ size_t nresources = 0;
+ acpi_status status;
+ int i;
+
+ status = acpi_get_table(ACPI_SIG_WDAT, 0,
+ (struct acpi_table_header **)&wdat);
+ if (ACPI_FAILURE(status)) {
+ /* It is fine if there is no WDAT */
+ return;
+ }
+
+ /* Watchdog disabled by BIOS */
+ if (!(wdat->flags & ACPI_WDAT_ENABLED))
+ return;
+
+ /* Skip legacy PCI WDT devices */
+ if (wdat->pci_segment != 0xff || wdat->pci_bus != 0xff ||
+ wdat->pci_device != 0xff || wdat->pci_function != 0xff)
+ return;
+
+ INIT_LIST_HEAD(&resource_list);
+
+ entries = (struct acpi_wdat_entry *)(wdat + 1);
+ for (i = 0; i < wdat->entries; i++) {
+ const struct acpi_generic_address *gas;
+ struct resource_entry *rentry;
+ struct resource res;
+ bool found;
+
+ gas = &entries[i].register_region;
+
+ res.start = gas->address;
+ if (gas->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) {
+ res.flags = IORESOURCE_MEM;
+ res.end = res.start + ALIGN(gas->access_width, 4);
+ } else if (gas->space_id == ACPI_ADR_SPACE_SYSTEM_IO) {
+ res.flags = IORESOURCE_IO;
+ res.end = res.start + gas->access_width;
+ } else {
+ pr_warn("Unsupported address space: %u\n",
+ gas->space_id);
+ goto fail_free_resource_list;
+ }
+
+ found = false;
+ resource_list_for_each_entry(rentry, &resource_list) {
+ if (resource_contains(rentry->res, &res)) {
+ found = true;
+ break;
+ }
+ }
+
+ if (!found) {
+ rentry = resource_list_create_entry(NULL, 0);
+ if (!rentry)
+ goto fail_free_resource_list;
+
+ *rentry->res = res;
+ resource_list_add_tail(rentry, &resource_list);
+ nresources++;
+ }
+ }
+
+ resources = kcalloc(nresources, sizeof(*resources), GFP_KERNEL);
+ if (!resources)
+ goto fail_free_resource_list;
+
+ i = 0;
+ resource_list_for_each_entry(rentry, &resource_list)
+ resources[i++] = *rentry->res;
+
+ pdev = platform_device_register_simple("wdat_wdt", PLATFORM_DEVID_NONE,
+ resources, nresources);
+ if (IS_ERR(pdev))
+ pr_err("Failed to create platform device\n");
+
+ kfree(resources);
+
+fail_free_resource_list:
+ resource_list_free(&resource_list);
+}
--- /dev/null
+/*
+ * ACPI Hardware Watchdog (WDAT) driver.
+ *
+ * Copyright (C) 2016, Intel Corporation
+ * Author: Mika Westerberg <mika.westerberg@linux.intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/acpi.h>
+#include <linux/ioport.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pm.h>
+#include <linux/watchdog.h>
+
+#define MAX_WDAT_ACTIONS ACPI_WDAT_ACTION_RESERVED
+
+/**
+ * struct wdat_instruction - Single ACPI WDAT instruction
+ * @entry: Copy of the ACPI table instruction
+ * @reg: Register the instruction is accessing
+ * @node: Next instruction in action sequence
+ */
+struct wdat_instruction {
+ struct acpi_wdat_entry entry;
+ void __iomem *reg;
+ struct list_head node;
+};
+
+/**
+ * struct wdat_wdt - ACPI WDAT watchdog device
+ * @pdev: Parent platform device
+ * @wdd: Watchdog core device
+ * @period: How long is one watchdog period in ms
+ * @stopped_in_sleep: Is this watchdog stopped by the firmware in S1-S5
+ * @stopped: Was the watchdog stopped by the driver in suspend
+ * @actions: An array of instruction lists indexed by an action number from
+ * the WDAT table. There can be %NULL entries for not implemented
+ * actions.
+ */
+struct wdat_wdt {
+ struct platform_device *pdev;
+ struct watchdog_device wdd;
+ unsigned int period;
+ bool stopped_in_sleep;
+ bool stopped;
+ struct list_head *instructions[MAX_WDAT_ACTIONS];
+};
+
+#define to_wdat_wdt(wdd) container_of(wdd, struct wdat_wdt, wdd)
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, bool, 0);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
+ __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+static int wdat_wdt_read(struct wdat_wdt *wdat,
+ const struct wdat_instruction *instr, u32 *value)
+{
+ const struct acpi_generic_address *gas = &instr->entry.register_region;
+
+ switch (gas->access_width) {
+ case 1:
+ *value = ioread8(instr->reg);
+ break;
+ case 2:
+ *value = ioread16(instr->reg);
+ break;
+ case 3:
+ *value = ioread32(instr->reg);
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ dev_dbg(&wdat->pdev->dev, "Read %#x from 0x%08llx\n", *value,
+ gas->address);
+
+ return 0;
+}
+
+static int wdat_wdt_write(struct wdat_wdt *wdat,
+ const struct wdat_instruction *instr, u32 value)
+{
+ const struct acpi_generic_address *gas = &instr->entry.register_region;
+
+ switch (gas->access_width) {
+ case 1:
+ iowrite8((u8)value, instr->reg);
+ break;
+ case 2:
+ iowrite16((u16)value, instr->reg);
+ break;
+ case 3:
+ iowrite32(value, instr->reg);
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ dev_dbg(&wdat->pdev->dev, "Wrote %#x to 0x%08llx\n", value,
+ gas->address);
+
+ return 0;
+}
+
+static int wdat_wdt_run_action(struct wdat_wdt *wdat, unsigned int action,
+ u32 param, u32 *retval)
+{
+ struct wdat_instruction *instr;
+
+ if (action >= ARRAY_SIZE(wdat->instructions))
+ return -EINVAL;
+
+ if (!wdat->instructions[action])
+ return -EOPNOTSUPP;
+
+ dev_dbg(&wdat->pdev->dev, "Running action %#x\n", action);
+
+ /* Run each instruction sequentially */
+ list_for_each_entry(instr, wdat->instructions[action], node) {
+ const struct acpi_wdat_entry *entry = &instr->entry;
+ const struct acpi_generic_address *gas;
+ u32 flags, value, mask, x, y;
+ bool preserve;
+ int ret;
+
+ gas = &entry->register_region;
+
+ preserve = entry->instruction & ACPI_WDAT_PRESERVE_REGISTER;
+ flags = entry->instruction & ~ACPI_WDAT_PRESERVE_REGISTER;
+ value = entry->value;
+ mask = entry->mask;
+
+ switch (flags) {
+ case ACPI_WDAT_READ_VALUE:
+ ret = wdat_wdt_read(wdat, instr, &x);
+ if (ret)
+ return ret;
+ x >>= gas->bit_offset;
+ x &= mask;
+ if (retval)
+ *retval = x == value;
+ break;
+
+ case ACPI_WDAT_READ_COUNTDOWN:
+ ret = wdat_wdt_read(wdat, instr, &x);
+ if (ret)
+ return ret;
+ x >>= gas->bit_offset;
+ x &= mask;
+ if (retval)
+ *retval = x;
+ break;
+
+ case ACPI_WDAT_WRITE_VALUE:
+ x = value & mask;
+ x <<= gas->bit_offset;
+ if (preserve) {
+ ret = wdat_wdt_read(wdat, instr, &y);
+ if (ret)
+ return ret;
+ y = y & ~(mask << gas->bit_offset);
+ x |= y;
+ }
+ ret = wdat_wdt_write(wdat, instr, x);
+ if (ret)
+ return ret;
+ break;
+
+ case ACPI_WDAT_WRITE_COUNTDOWN:
+ x = param;
+ x &= mask;
+ x <<= gas->bit_offset;
+ if (preserve) {
+ ret = wdat_wdt_read(wdat, instr, &y);
+ if (ret)
+ return ret;
+ y = y & ~(mask << gas->bit_offset);
+ x |= y;
+ }
+ ret = wdat_wdt_write(wdat, instr, x);
+ if (ret)
+ return ret;
+ break;
+
+ default:
+ dev_err(&wdat->pdev->dev, "Unknown instruction: %u\n",
+ flags);
+ return -EINVAL;
+ }
+ }
+
+ return 0;
+}
+
+static int wdat_wdt_enable_reboot(struct wdat_wdt *wdat)
+{
+ int ret;
+
+ /*
+ * WDAT specification says that the watchdog is required to reboot
+ * the system when it fires. However, it also states that it is
+ * recommeded to make it configurable through hardware register. We
+ * enable reboot now if it is configrable, just in case.
+ */
+ ret = wdat_wdt_run_action(wdat, ACPI_WDAT_SET_REBOOT, 0, 0);
+ if (ret && ret != -EOPNOTSUPP) {
+ dev_err(&wdat->pdev->dev,
+ "Failed to enable reboot when watchdog triggers\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+static void wdat_wdt_boot_status(struct wdat_wdt *wdat)
+{
+ u32 boot_status = 0;
+ int ret;
+
+ ret = wdat_wdt_run_action(wdat, ACPI_WDAT_GET_STATUS, 0, &boot_status);
+ if (ret && ret != -EOPNOTSUPP) {
+ dev_err(&wdat->pdev->dev, "Failed to read boot status\n");
+ return;
+ }
+
+ if (boot_status)
+ wdat->wdd.bootstatus = WDIOF_CARDRESET;
+
+ /* Clear the boot status in case BIOS did not do it */
+ ret = wdat_wdt_run_action(wdat, ACPI_WDAT_SET_STATUS, 0, 0);
+ if (ret && ret != -EOPNOTSUPP)
+ dev_err(&wdat->pdev->dev, "Failed to clear boot status\n");
+}
+
+static void wdat_wdt_set_running(struct wdat_wdt *wdat)
+{
+ u32 running = 0;
+ int ret;
+
+ ret = wdat_wdt_run_action(wdat, ACPI_WDAT_GET_RUNNING_STATE, 0,
+ &running);
+ if (ret && ret != -EOPNOTSUPP)
+ dev_err(&wdat->pdev->dev, "Failed to read running state\n");
+
+ if (running)
+ set_bit(WDOG_HW_RUNNING, &wdat->wdd.status);
+}
+
+static int wdat_wdt_start(struct watchdog_device *wdd)
+{
+ return wdat_wdt_run_action(to_wdat_wdt(wdd),
+ ACPI_WDAT_SET_RUNNING_STATE, 0, NULL);
+}
+
+static int wdat_wdt_stop(struct watchdog_device *wdd)
+{
+ return wdat_wdt_run_action(to_wdat_wdt(wdd),
+ ACPI_WDAT_SET_STOPPED_STATE, 0, NULL);
+}
+
+static int wdat_wdt_ping(struct watchdog_device *wdd)
+{
+ return wdat_wdt_run_action(to_wdat_wdt(wdd), ACPI_WDAT_RESET, 0, NULL);
+}
+
+static int wdat_wdt_set_timeout(struct watchdog_device *wdd,
+ unsigned int timeout)
+{
+ struct wdat_wdt *wdat = to_wdat_wdt(wdd);
+ unsigned int periods;
+ int ret;
+
+ periods = timeout * 1000 / wdat->period;
+ ret = wdat_wdt_run_action(wdat, ACPI_WDAT_SET_COUNTDOWN, periods, NULL);
+ if (!ret)
+ wdd->timeout = timeout;
+ return ret;
+}
+
+static unsigned int wdat_wdt_get_timeleft(struct watchdog_device *wdd)
+{
+ struct wdat_wdt *wdat = to_wdat_wdt(wdd);
+ u32 periods = 0;
+
+ wdat_wdt_run_action(wdat, ACPI_WDAT_GET_COUNTDOWN, 0, &periods);
+ return periods * wdat->period / 1000;
+}
+
+static const struct watchdog_info wdat_wdt_info = {
+ .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
+ .firmware_version = 0,
+ .identity = "wdat_wdt",
+};
+
+static const struct watchdog_ops wdat_wdt_ops = {
+ .owner = THIS_MODULE,
+ .start = wdat_wdt_start,
+ .stop = wdat_wdt_stop,
+ .ping = wdat_wdt_ping,
+ .set_timeout = wdat_wdt_set_timeout,
+ .get_timeleft = wdat_wdt_get_timeleft,
+};
+
+static int wdat_wdt_probe(struct platform_device *pdev)
+{
+ const struct acpi_wdat_entry *entries;
+ const struct acpi_table_wdat *tbl;
+ struct wdat_wdt *wdat;
+ struct resource *res;
+ void __iomem **regs;
+ acpi_status status;
+ int i, ret;
+
+ status = acpi_get_table(ACPI_SIG_WDAT, 0,
+ (struct acpi_table_header **)&tbl);
+ if (ACPI_FAILURE(status))
+ return -ENODEV;
+
+ wdat = devm_kzalloc(&pdev->dev, sizeof(*wdat), GFP_KERNEL);
+ if (!wdat)
+ return -ENOMEM;
+
+ regs = devm_kcalloc(&pdev->dev, pdev->num_resources, sizeof(*regs),
+ GFP_KERNEL);
+ if (!regs)
+ return -ENOMEM;
+
+ /* WDAT specification wants to have >= 1ms period */
+ if (tbl->timer_period < 1)
+ return -EINVAL;
+ if (tbl->min_count > tbl->max_count)
+ return -EINVAL;
+
+ wdat->period = tbl->timer_period;
+ wdat->wdd.min_hw_heartbeat_ms = wdat->period * tbl->min_count;
+ wdat->wdd.max_hw_heartbeat_ms = wdat->period * tbl->max_count;
+ wdat->stopped_in_sleep = tbl->flags & ACPI_WDAT_STOPPED;
+ wdat->wdd.info = &wdat_wdt_info;
+ wdat->wdd.ops = &wdat_wdt_ops;
+ wdat->pdev = pdev;
+
+ /* Request and map all resources */
+ for (i = 0; i < pdev->num_resources; i++) {
+ void __iomem *reg;
+
+ res = &pdev->resource[i];
+ if (resource_type(res) == IORESOURCE_MEM) {
+ reg = devm_ioremap_resource(&pdev->dev, res);
+ } else if (resource_type(res) == IORESOURCE_IO) {
+ reg = devm_ioport_map(&pdev->dev, res->start, 1);
+ } else {
+ dev_err(&pdev->dev, "Unsupported resource\n");
+ return -EINVAL;
+ }
+
+ if (!reg)
+ return -ENOMEM;
+
+ regs[i] = reg;
+ }
+
+ entries = (struct acpi_wdat_entry *)(tbl + 1);
+ for (i = 0; i < tbl->entries; i++) {
+ const struct acpi_generic_address *gas;
+ struct wdat_instruction *instr;
+ struct list_head *instructions;
+ unsigned int action;
+ struct resource r;
+ int j;
+
+ action = entries[i].action;
+ if (action >= MAX_WDAT_ACTIONS) {
+ dev_dbg(&pdev->dev, "Skipping unknown action: %u\n",
+ action);
+ continue;
+ }
+
+ instr = devm_kzalloc(&pdev->dev, sizeof(*instr), GFP_KERNEL);
+ if (!instr)
+ return -ENOMEM;
+
+ INIT_LIST_HEAD(&instr->node);
+ instr->entry = entries[i];
+
+ gas = &entries[i].register_region;
+
+ memset(&r, 0, sizeof(r));
+ r.start = gas->address;
+ r.end = r.start + gas->access_width;
+ if (gas->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) {
+ r.flags = IORESOURCE_MEM;
+ } else if (gas->space_id == ACPI_ADR_SPACE_SYSTEM_IO) {
+ r.flags = IORESOURCE_IO;
+ } else {
+ dev_dbg(&pdev->dev, "Unsupported address space: %d\n",
+ gas->space_id);
+ continue;
+ }
+
+ /* Find the matching resource */
+ for (j = 0; j < pdev->num_resources; j++) {
+ res = &pdev->resource[j];
+ if (resource_contains(res, &r)) {
+ instr->reg = regs[j] + r.start - res->start;
+ break;
+ }
+ }
+
+ if (!instr->reg) {
+ dev_err(&pdev->dev, "I/O resource not found\n");
+ return -EINVAL;
+ }
+
+ instructions = wdat->instructions[action];
+ if (!instructions) {
+ instructions = devm_kzalloc(&pdev->dev,
+ sizeof(*instructions), GFP_KERNEL);
+ if (!instructions)
+ return -ENOMEM;
+
+ INIT_LIST_HEAD(instructions);
+ wdat->instructions[action] = instructions;
+ }
+
+ list_add_tail(&instr->node, instructions);
+ }
+
+ wdat_wdt_boot_status(wdat);
+ wdat_wdt_set_running(wdat);
+
+ ret = wdat_wdt_enable_reboot(wdat);
+ if (ret)
+ return ret;
+
+ platform_set_drvdata(pdev, wdat);
+
+ watchdog_set_nowayout(&wdat->wdd, nowayout);
+ return devm_watchdog_register_device(&pdev->dev, &wdat->wdd);
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int wdat_wdt_suspend_noirq(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct wdat_wdt *wdat = platform_get_drvdata(pdev);
+ int ret;
+
+ if (!watchdog_active(&wdat->wdd))
+ return 0;
+
+ /*
+ * We need to stop the watchdog if firmare is not doing it or if we
+ * are going suspend to idle (where firmware is not involved). If
+ * firmware is stopping the watchdog we kick it here one more time
+ * to give it some time.
+ */
+ wdat->stopped = false;
+ if (acpi_target_system_state() == ACPI_STATE_S0 ||
+ !wdat->stopped_in_sleep) {
+ ret = wdat_wdt_stop(&wdat->wdd);
+ if (!ret)
+ wdat->stopped = true;
+ } else {
+ ret = wdat_wdt_ping(&wdat->wdd);
+ }
+
+ return ret;
+}
+
+static int wdat_wdt_resume_noirq(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct wdat_wdt *wdat = platform_get_drvdata(pdev);
+ int ret;
+
+ if (!watchdog_active(&wdat->wdd))
+ return 0;
+
+ if (!wdat->stopped) {
+ /*
+ * Looks like the boot firmware reinitializes the watchdog
+ * before it hands off to the OS on resume from sleep so we
+ * stop and reprogram the watchdog here.
+ */
+ ret = wdat_wdt_stop(&wdat->wdd);
+ if (ret)
+ return ret;
+
+ ret = wdat_wdt_set_timeout(&wdat->wdd, wdat->wdd.timeout);
+ if (ret)
+ return ret;
+
+ ret = wdat_wdt_enable_reboot(wdat);
+ if (ret)
+ return ret;
+ }
+
+ return wdat_wdt_start(&wdat->wdd);
+}
+#endif
+
+static const struct dev_pm_ops wdat_wdt_pm_ops = {
+ SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(wdat_wdt_suspend_noirq,
+ wdat_wdt_resume_noirq)
+};
+
+static struct platform_driver wdat_wdt_driver = {
+ .probe = wdat_wdt_probe,
+ .driver = {
+ .name = "wdat_wdt",
+ .pm = &wdat_wdt_pm_ops,
+ },
+};
+
+module_platform_driver(wdat_wdt_driver);
+
+MODULE_AUTHOR("Mika Westerberg <mika.westerberg@linux.intel.com>");
+MODULE_DESCRIPTION("ACPI Hardware Watchdog (WDAT) driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:wdat_wdt");
projects / platform / kernel / linux-rpi3.git / commitdiff