On 12/10/2016 02:25 AM, Hui Chun Ong wrote:
Add support for the watchdog timer on PXI Embedded Controller.
Signed-off-by: Hui Chun Ong <hui.chun....@ni.com>
---
v2: Remove mutex lock and platform_device *pdev fields from struct nic7018_wdt.
Update config NIC7018_WDT description.
Update nic7018_get_config() to never return error.
Remove checking for IO resource size in nic7018_probe().
v1: Remove non-standard attributes.
Change from acpi_driver to platform_driver.
Rename driver from ni7018_wdt to nic7018_wdt.
---
Documentation/watchdog/watchdog-parameters.txt | 5 +
drivers/watchdog/Kconfig | 10 +
drivers/watchdog/Makefile | 1 +
drivers/watchdog/nic7018_wdt.c | 277 +++++++++++++++++++++++++
4 files changed, 293 insertions(+)
create mode 100644 drivers/watchdog/nic7018_wdt.c
diff --git a/Documentation/watchdog/watchdog-parameters.txt
b/Documentation/watchdog/watchdog-parameters.txt
index a8d3642..bd142fa 100644
--- a/Documentation/watchdog/watchdog-parameters.txt
+++ b/Documentation/watchdog/watchdog-parameters.txt
@@ -209,6 +209,11 @@ timeout: Initial watchdog timeout in seconds
(0<timeout<516, default=60)
nowayout: Watchdog cannot be stopped once started
(default=kernel config parameter)
-------------------------------------------------
+nic7018_wdt:
+timeout: Initial watchdog timeout in seconds (0<timeout<464, default=80)
+nowayout: Watchdog cannot be stopped once started
+ (default=kernel config parameter)
+-------------------------------------------------
nuc900_wdt:
heartbeat: Watchdog heartbeats in seconds.
(default = 15)
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index fdd3228..baa79825 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -1325,6 +1325,16 @@ config NI903X_WDT
To compile this driver as a module, choose M here: the module will be
called ni903x_wdt.
+config NIC7018_WDT
+ tristate "NIC7018 Watchdog"
+ depends on X86 && ACPI
+ select WATCHDOG_CORE
+ ---help---
+ Support for National Instruments NIC7018 Watchdog.
+
+ To compile this driver as a module, choose M here: the module will be
+ called nic7018_wdt.
+
# M32R Architecture
# M68K Architecture
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index caa9f4a..bd88e2e 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -139,6 +139,7 @@ obj-$(CONFIG_INTEL_SCU_WATCHDOG) += intel_scu_watchdog.o
obj-$(CONFIG_INTEL_MID_WATCHDOG) += intel-mid_wdt.o
obj-$(CONFIG_INTEL_MEI_WDT) += mei_wdt.o
obj-$(CONFIG_NI903X_WDT) += ni903x_wdt.o
+obj-$(CONFIG_NIC7018_WDT) += nic7018_wdt.o
# M32R Architecture
diff --git a/drivers/watchdog/nic7018_wdt.c b/drivers/watchdog/nic7018_wdt.c
new file mode 100644
index 0000000..9b7b8d3
--- /dev/null
+++ b/drivers/watchdog/nic7018_wdt.c
@@ -0,0 +1,277 @@
+/*
+ * Copyright (C) 2016 National Instruments Corp.
+ *
+ * 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.
+ */
+
+#include <linux/acpi.h>
+#include <linux/bitops.h>
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/watchdog.h>
+
+#define LOCK 0xA5
+#define UNLOCK 0x5A
+
+#define WDT_CTRL_RESET_EN BIT(7)
+#define WDT_RELOAD_PORT_EN BIT(7)
+
+#define WDT_CTRL 1
+#define WDT_RELOAD_CTRL 2
+#define WDT_PRESET_PRESCALE 4
+#define WDT_REG_LOCK 5
+#define WDT_COUNT 6
+#define WDT_RELOAD_PORT 7
+
+#define WDT_MIN_TIMEOUT 1
+#define WDT_MAX_TIMEOUT 464
+#define WDT_DEFAULT_TIMEOUT 80
+
+#define WDT_MAX_COUNTER 15
+
+static unsigned int timeout;
+module_param(timeout, uint, 0);
+MODULE_PARM_DESC(timeout,
+ "Watchdog timeout in seconds. (default="
+ __MODULE_STRING(WDT_DEFAULT_TIMEOUT) ")");
+
+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) ")");
+
+struct nic7018_wdt {
+ u16 io_base;
+ u32 period_ms;
+ struct watchdog_device wdd;
+};
+
+struct nic7018_config {
+ u32 period_ms;
+ u8 divider;
+};
+
+static const struct nic7018_config nic7018_configs[] = {
+ { 125, 3 },
The maximum timeout is (125 * 15) - 62, or 1813 ms. This will never be selected,
since with a timeout of 2s count will be 17 below, and the entry will be
skipped.
With a timeout of 1000, the second table entry will be used as well since the
timeout with the first entry is not exactly 1 second.
Given that, you might as well drop this entry.
+ { 2000, 4 },
+ { 32000, 5 },
+};
+
+static inline u32 nic7018_timeout_ms(u32 period_ms, u8 counter)
+{
+ return period_ms * counter - period_ms / 2;
+}
+
+static const struct nic7018_config *nic7018_get_config(u32 timeout_ms,
+ u8 *counter)
+{
+ u32 delta, i, best_delta = U32_MAX;
+ const struct nic7018_config *config, *best_config = NULL;
+ u8 count;
+ *counter = WDT_MAX_COUNTER;
+
+ for (i = 0; i < ARRAY_SIZE(nic7018_configs); i++) {
+ config = &nic7018_configs[i];
+
+ count = DIV_ROUND_UP(timeout_ms + config->period_ms / 2,
+ config->period_ms);
+
+ if (count > WDT_MAX_COUNTER)
+ continue;
+
+ delta = nic7018_timeout_ms(config->period_ms, count) -
+ timeout_ms;
+
+ if (delta < best_delta) {
+ best_delta = delta;
+ best_config = config;
+ *counter = count;
+ }
+ }
+
+ return (!best_config) ? config : best_config;
Unecessary (), and
return best_config ? : config;
works without the '!'.
Also, given the above, it seems to me that
if (timeout < 30 && timeout != 16) {
config = &nic7018_configs[0];
count = timeout / 2 + 1;
} else {
config = &nic7018_configs[1];
count = DIV_ROUND_UP(timeout + 16, 32);
if (count > WDT_MAX_COUNTER;
count = WDT_MAX_COUNTER;
}
*counter = count;
return config;
would accomplish the same as your code and be much less complex and easier
to understand. As a side effect, you could keep all timeouts in seconds
and would not have to deal with milliseconds at all.
+}
+
+static int nic7018_set_timeout(struct watchdog_device *wdd,
+ unsigned int timeout)
+{
+ struct nic7018_wdt *wdt = watchdog_get_drvdata(wdd);
+ const struct nic7018_config *config;
+ u8 counter;
+
+ config = nic7018_get_config(timeout * 1000, &counter);
+
+ outb(counter << 4 | config->divider,
+ wdt->io_base + WDT_PRESET_PRESCALE);
+
+ wdd->timeout = nic7018_timeout_ms(config->period_ms, counter) / 1000;
+ wdt->period_ms = config->period_ms;
+
+ return 0;
+}
+
+static int nic7018_start(struct watchdog_device *wdd)
+{
+ struct nic7018_wdt *wdt = watchdog_get_drvdata(wdd);
+ u8 control;
+
+ nic7018_set_timeout(wdd, wdd->timeout);
+
+ control = inb(wdt->io_base + WDT_RELOAD_CTRL);
+ outb(control | WDT_RELOAD_PORT_EN, wdt->io_base + WDT_RELOAD_CTRL);
+
+ outb(1, wdt->io_base + WDT_RELOAD_PORT);
+
+ control = inb(wdt->io_base + WDT_CTRL);
+ outb(control | WDT_CTRL_RESET_EN, wdt->io_base + WDT_CTRL);
+
+ return 0;
+}
+
+static int nic7018_stop(struct watchdog_device *wdd)
+{
+ struct nic7018_wdt *wdt = watchdog_get_drvdata(wdd);
+
+ outb(0, wdt->io_base + WDT_CTRL);
+ outb(0, wdt->io_base + WDT_RELOAD_CTRL);
+ outb(0xF0, wdt->io_base + WDT_PRESET_PRESCALE);
+
+ return 0;
+}
+
+static int nic7018_ping(struct watchdog_device *wdd)
+{
+ struct nic7018_wdt *wdt = watchdog_get_drvdata(wdd);
+
+ outb(1, wdt->io_base + WDT_RELOAD_PORT);
+
+ return 0;
+}
+
+static unsigned int nic7018_get_timeleft(struct watchdog_device *wdd)
+{
+ struct nic7018_wdt *wdt = watchdog_get_drvdata(wdd);
+ u8 count;
+
+ count = inb(wdt->io_base + WDT_COUNT) & 0xF;
+
+ if (!count)
+ return 0;
+
+ return nic7018_timeout_ms(wdt->period_ms, count) / 1000;
+}
+
+static const struct watchdog_info nic7018_wdd_info = {
+ .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
+ .identity = "NIC7018 Watchdog",
+};
+
+static const struct watchdog_ops nic7018_wdd_ops = {
+ .owner = THIS_MODULE,
+ .start = nic7018_start,
+ .stop = nic7018_stop,
+ .ping = nic7018_ping,
+ .set_timeout = nic7018_set_timeout,
+ .get_timeleft = nic7018_get_timeleft,
+};
+
+static int nic7018_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct watchdog_device *wdd;
+ struct nic7018_wdt *wdt;
+ struct resource *io_rc;
+ int ret;
+
+ wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
+ if (!wdt)
+ return -ENOMEM;
+
+ platform_set_drvdata(pdev, wdt);
+
+ io_rc = platform_get_resource(pdev, IORESOURCE_IO, 0);
+ if (!io_rc) {
+ dev_err(dev, "missing IO resources\n");
+ return -EINVAL;
+ }
+
+ if (!devm_request_region(dev, io_rc->start, resource_size(io_rc),
+ KBUILD_MODNAME)) {
+ dev_err(dev, "failed to get IO region\n");
+ return -EBUSY;
+ }
+
+ wdt->io_base = io_rc->start;
+ wdd = &wdt->wdd;
+ wdd->info = &nic7018_wdd_info;
+ wdd->ops = &nic7018_wdd_ops;
+ wdd->min_timeout = WDT_MIN_TIMEOUT;
+ wdd->max_timeout = WDT_MAX_TIMEOUT;
+ wdd->timeout = WDT_DEFAULT_TIMEOUT;
+ wdd->parent = dev;
+
+ watchdog_set_drvdata(wdd, wdt);
+ watchdog_set_nowayout(wdd, nowayout);
+
+ ret = watchdog_init_timeout(wdd, timeout, dev);
+ if (ret)
+ dev_warn(dev, "unable to set timeout value, using default\n");
+
+ ret = watchdog_register_device(wdd);
+ if (ret) {
+ dev_err(dev, "failed to register watchdog\n");
+ return ret;
+ }
+
+ /* Unlock WDT register */
+ outb(UNLOCK, wdt->io_base + WDT_REG_LOCK);
+
The watchdog driver may be opened right after the call to
watchdog_register_device(),
meaning this is racy since the open may already have happened. You'll need to
set
this before the call to watchdog_register_device().
+ dev_dbg(dev, "io_base=0x%04X, timeout=%d, nowayout=%d\n",
+ wdt->io_base, timeout, nowayout);
+ return 0;
+}
+
+static int nic7018_remove(struct platform_device *pdev)
+{
+ struct nic7018_wdt *wdt = platform_get_drvdata(pdev);
+
+ nic7018_stop(&wdt->wdd);
+ watchdog_unregister_device(&wdt->wdd);
+
+ /* Lock WDT register */
+ outb(LOCK, wdt->io_base + WDT_REG_LOCK);
+
+ return 0;
+}
+
+static const struct acpi_device_id nic7018_device_ids[] = {
+ {"NIC7018", 0},
+ {"", 0},
+};
+MODULE_DEVICE_TABLE(acpi, nic7018_device_ids);
+
+static struct platform_driver watchdog_driver = {
+ .probe = nic7018_probe,
+ .remove = nic7018_remove,
+ .driver = {
+ .name = KBUILD_MODNAME,
+ .acpi_match_table = ACPI_PTR(nic7018_device_ids),
+ },
+};
+
+module_platform_driver(watchdog_driver);
+
+MODULE_DESCRIPTION("National Instruments NIC7018 Watchdog driver");
+MODULE_AUTHOR("Hui Chun Ong <hui.chun....@ni.com>");
+MODULE_LICENSE("GPL");
--
2.7.4
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