Hi Guenter,
I'll remove all the attributes for this patch and post a separate patch
with the attributes and explanation for the need and usage of those
attributes.
rgds
Hui Chun
On Fri, 2016-10-28 at 10:25 -0700, Guenter Roeck wrote:
> Hi,
>
> On Fri, Oct 28, 2016 at 03:51:07PM +0800, Hui Chun Ong wrote:
> >
> > Add support for the watchdog timer on PXI Embedded Controller.
> >
> > Signed-off-by: Hui Chun Ong <hui.chun....@ni.com>
> The problem with your patch are the non-standard attributes it introduces.
>
> +static WDT_ATTR(enable_reset, WDT_CTRL, WDT_CTRL_RESET_EN);
> +static WDT_ATTR(enable_soft_ping, WDT_RELOAD_CTRL, WDT_RELOAD_PORT_EN);
> +static WDT_ATTR(trigger_polarity, WDT_CTRL, WDT_CTRL_TRIG_POLARITY);
> +static WDT_ATTR(keepalive_trigger_polarity, WDT_RELOAD_CTRL,
> + WDT_RELOAD_TRIG_POLARITY);
>
> At first glance, those appear to be platform configuration parameters,
> which should either be hard-coded or configured through devicetree /
> platform data. Whatever it is, such non-standard attributes consume a
> large amount of time, since reviewers will have to understand what the
> attributes are used for. On top of that, it is likely that we'll probably
> need several rounds of reviews and arguments to determine if the attributes
> are really needed or inappropriate. This all takes a lot of time from
> reviewers. Because of that, patches like this tend to end up at the end
> of my review queue.
>
> Guenter
>
> >
> > ---
> > Documentation/watchdog/watchdog-parameters.txt | 5 +
> > drivers/watchdog/Kconfig | 11 +
> > drivers/watchdog/Makefile | 1 +
> > drivers/watchdog/ni7018_wdt.c | 506
> > +++++++++++++++++++++++++
> > 4 files changed, 523 insertions(+)
> > create mode 100644 drivers/watchdog/ni7018_wdt.c
> >
> > diff --git a/Documentation/watchdog/watchdog-parameters.txt
> > b/Documentation/watchdog/watchdog-parameters.txt
> > index a8d3642..25dbfa2 100644
> > --- a/Documentation/watchdog/watchdog-parameters.txt
> > +++ b/Documentation/watchdog/watchdog-parameters.txt
> > @@ -204,6 +204,11 @@ mv64x60_wdt:
> > nowayout: Watchdog cannot be stopped once started
> > (default=kernel config parameter)
> > -------------------------------------------------
> > +ni7018_wdt:
> > +timeout: Initial watchdog timeout in seconds (0
> > +nowayout: Watchdog cannot be stopped once started
> > + (default=kernel config parameter)
> > +-------------------------------------------------
> > ni903x_wdt:
> > timeout: Initial watchdog timeout in seconds (0
> > nowayout: Watchdog cannot be stopped once started
> > diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
> > index fdd3228..6d185af 100644
> > --- a/drivers/watchdog/Kconfig
> > +++ b/drivers/watchdog/Kconfig
> > @@ -1314,6 +1314,17 @@ config INTEL_MEI_WDT
> > To compile this driver as a module, choose M here:
> > the module will be called mei_wdt.
> >
> > +config NI7018_WDT
> > + tristate "NI 7018 Watchdog"
> > + depends on X86 && ACPI
> > + select WATCHDOG_CORE
> > + ---help---
> > + This is the device driver for National Instruments NIC7018 watchdog
> > + timer.
> > +
> > + To compile this driver as a module, choose M here: the module will be
> > + called ni7018_wdt.
> > +
> > config NI903X_WDT
> > tristate "NI 903x/913x Watchdog"
> > depends on X86 && ACPI
> > diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
> > index caa9f4a..4605cd2 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_NI7018_WDT) += ni7018_wdt.o
> >
> > # M32R Architecture
> >
> > diff --git a/drivers/watchdog/ni7018_wdt.c b/drivers/watchdog/ni7018_wdt.c
> > new file mode 100644
> > index 0000000..7690314
> > --- /dev/null
> > +++ b/drivers/watchdog/ni7018_wdt.c
> > @@ -0,0 +1,506 @@
> > +/*
> > + * 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
> > +#include
> > +#include
> > +#include
> > +#include
> > +#include
> > +#include
> > +
> > +#define LOCK 0xA5
> > +#define UNLOCK 0x5A
> > +
> > +#define WDT_CTRL_RESET_EN BIT(7)
> > +#define WDT_CTRL_TRIG_POLARITY BIT(4)
> > +#define WDT_CTRL_TRIG 0x0F
> > +
> > +#define WDT_RELOAD_PORT_EN BIT(7)
> > +#define WDT_RELOAD_TRIG_POLARITY BIT(6)
> > +#define WDT_RELOAD_TRIG 0x0F
> > +#define WDT_MIN_TRIG_NUM 0
> > +#define WDT_MAX_TRIG_NUM 8
> > +
> > +#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_IO_SIZE 8
> > +
> > +#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 int nowayout = WATCHDOG_NOWAYOUT;
> > +module_param(nowayout, int, S_IRUGO);
> > +MODULE_PARM_DESC(nowayout,
> > + "Watchdog cannot be stopped once started. (default="
> > + __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
> > +
> > +struct ni7018_wdt {
> > + struct device *dev;
> > + u16 io_base;
> > + u32 period_ms;
> > + struct mutex lock;
> > + struct watchdog_device wdd;
> > +};
> > +
> > +struct ni7018_config {
> > + u32 period_ms;
> > + u8 divider;
> > +};
> > +
> > +static const struct ni7018_config ni7018_configs[] = {
> > + { 125, 3 },
> > + { 2000, 4 },
> > + { 32000, 5 },
> > +};
> > +
> > +static inline u32 ni7018_timeout_ms(u32 period_ms, u8 counter)
> > +{
> > + return period_ms * counter - period_ms / 2;
> > +}
> > +
> > +static const struct ni7018_config *ni7018_get_config(u32 timeout_ms,
> > + u8 *counter)
> > +{
> > + u32 delta, i, best_delta = U32_MAX;
> > + const struct ni7018_config *config, *best_config = NULL;
> > + u8 count;
> > +
> > + for (i = 0; i < ARRAY_SIZE(ni7018_configs); i++) {
> > + config = &ni7018_configs[i];
> > +
> > + count = DIV_ROUND_UP(timeout_ms + config->period_ms / 2,
> > + config->period_ms);
> > +
> > + if (count > WDT_MAX_COUNTER)
> > + continue;
> > +
> > + delta = ni7018_timeout_ms(config->period_ms, count) -
> > + timeout_ms;
> > +
> > + if (delta < best_delta) {
> > + best_delta = delta;
> > + best_config = config;
> > + *counter = count;
> > + }
> > + }
> > + return best_config;
> > +}
> > +
> > +static int ni7018_set_timeout(struct watchdog_device *wdd,
> > + unsigned int timeout)
> > +{
> > + struct ni7018_wdt *wdt = watchdog_get_drvdata(wdd);
> > + const struct ni7018_config *config;
> > + u8 counter;
> > +
> > + config = ni7018_get_config(timeout * 1000, &counter);
> > + if (!config)
> > + return -EINVAL;
> > +
> > + mutex_lock(&wdt->lock);
> > +
> > + outb(counter << 4 | config->divider,
> > + wdt->io_base + WDT_PRESET_PRESCALE);
> > +
> > + wdd->timeout = ni7018_timeout_ms(config->period_ms, counter) / 1000;
> > + wdt->period_ms = config->period_ms;
> > +
> > + mutex_unlock(&wdt->lock);
> > + return 0;
> > +}
> > +
> > +static int ni7018_start(struct watchdog_device *wdd)
> > +{
> > + struct ni7018_wdt *wdt = watchdog_get_drvdata(wdd);
> > + u8 control;
> > +
> > + ni7018_set_timeout(wdd, wdd->timeout);
> > +
> > + mutex_lock(&wdt->lock);
> > +
> > + 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);
> > +
> > + mutex_unlock(&wdt->lock);
> > + return 0;
> > +}
> > +
> > +static int ni7018_stop(struct watchdog_device *wdd)
> > +{
> > + struct ni7018_wdt *wdt = watchdog_get_drvdata(wdd);
> > +
> > + mutex_lock(&wdt->lock);
> > +
> > + outb(0, wdt->io_base + WDT_CTRL);
> > + outb(0, wdt->io_base + WDT_RELOAD_CTRL);
> > + outb(0xF0, wdt->io_base + WDT_PRESET_PRESCALE);
> > +
> > + mutex_unlock(&wdt->lock);
> > + return 0;
> > +}
> > +
> > +static int ni7018_ping(struct watchdog_device *wdd)
> > +{
> > + struct ni7018_wdt *wdt = watchdog_get_drvdata(wdd);
> > +
> > + mutex_lock(&wdt->lock);
> > +
> > + outb(1, wdt->io_base + WDT_RELOAD_PORT);
> > +
> > + mutex_unlock(&wdt->lock);
> > + return 0;
> > +}
> > +
> > +static unsigned int ni7018_get_timeleft(struct watchdog_device *wdd)
> > +{
> > + struct ni7018_wdt *wdt = watchdog_get_drvdata(wdd);
> > + u8 count;
> > +
> > + mutex_lock(&wdt->lock);
> > +
> > + count = inb(wdt->io_base + WDT_COUNT) & 0xF;
> > +
> > + mutex_unlock(&wdt->lock);
> > +
> > + if (!count)
> > + return 0;
> > +
> > + return ni7018_timeout_ms(wdt->period_ms, count) / 1000;
> > +}
> > +
> > +static acpi_status
> > +ni7018_resources(struct acpi_resource *res, void *data)
> > +{
> > + struct ni7018_wdt *wdt = data;
> > + u16 io_size;
> > +
> > + switch (res->type) {
> > + case ACPI_RESOURCE_TYPE_IO:
> > + if (wdt->io_base != 0) {
> > + dev_err(wdt->dev, "too many IO resources\n");
> > + return AE_ERROR;
> > + }
> > +
> > + wdt->io_base = res->data.io.minimum;
> > + io_size = res->data.io.address_length;
> > +
> > + if (io_size < WDT_IO_SIZE) {
> > + dev_err(wdt->dev, "memory region too small\n");
> > + return AE_ERROR;
> > + }
> > +
> > + if (!devm_request_region(wdt->dev, wdt->io_base, io_size,
> > + KBUILD_MODNAME)) {
> > + dev_err(wdt->dev, "failed to get memory region\n");
> > + return AE_ERROR;
> > + }
> > +
> > + return AE_OK;
> > +
> > + default:
> > + /* Ignore unsupported resources */
> > + return AE_OK;
> > + }
> > +}
> > +
> > +static const struct watchdog_info ni7018_wdd_info = {
> > + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
> > + .identity = "NI 7018 Watchdog",
> > +};
> > +
> > +static const struct watchdog_ops ni7018_wdd_ops = {
> > + .owner = THIS_MODULE,
> > + .start = ni7018_start,
> > + .stop = ni7018_stop,
> > + .ping = ni7018_ping,
> > + .set_timeout = ni7018_set_timeout,
> > + .get_timeleft = ni7018_get_timeleft,
> > +};
> > +
> > +struct ni7018_attr {
> > + struct device_attribute dev_attr;
> > + u8 offset;
> > + u8 bit;
> > +};
> > +#define to_ni7018_attr(_attr) \
> > + container_of((_attr), struct ni7018_attr, dev_attr)
> > +
> > +static ssize_t wdt_attr_show(struct device *dev,
> > + struct device_attribute *da,
> > + char *buf)
> > +{
> > + struct watchdog_device *wdd = dev_get_drvdata(dev);
> > + struct ni7018_wdt *wdt = watchdog_get_drvdata(wdd);
> > + struct ni7018_attr *attr = to_ni7018_attr(da);
> > + u8 control;
> > + size_t ret;
> > +
> > + mutex_lock(&wdt->lock);
> > +
> > + control = inb(wdt->io_base + attr->offset);
> > +
> > + mutex_unlock(&wdt->lock);
> > +
> > + ret = sprintf(buf, "%u\n", !!(control & attr->bit));
> > + return ret;
> > +}
> > +
> > +static ssize_t wdt_attr_store(struct device *dev,
> > + struct device_attribute *da,
> > + const char *buf,
> > + size_t size)
> > +{
> > + struct watchdog_device *wdd = dev_get_drvdata(dev);
> > + struct ni7018_wdt *wdt = watchdog_get_drvdata(wdd);
> > + struct ni7018_attr *attr = to_ni7018_attr(da);
> > + unsigned long val;
> > + u8 control;
> > +
> > + int ret = kstrtoul(buf, 10, &val);
> > +
> > + if (ret)
> > + return ret;
> > +
> > + if (val < 0 || val > 1)
> > + return -EINVAL;
> > +
> > + mutex_lock(&wdt->lock);
> > +
> > + control = inb(wdt->io_base + attr->offset);
> > + if (val)
> > + outb(control | attr->bit, wdt->io_base + attr->offset);
> > + else
> > + outb(control & ~attr->bit, wdt->io_base + attr->offset);
> > +
> > + mutex_unlock(&wdt->lock);
> > + return size;
> > +}
> > +
> > +#define WDT_ATTR(_name, _offset, _bit) \
> > + struct ni7018_attr dev_attr_##_name = { \
> > + .offset = _offset, \
> > + .bit = _bit, \
> > + .dev_attr = \
> > + __ATTR(_name, S_IWUSR | S_IRUGO, \
> > + wdt_attr_show, wdt_attr_store), \
> > + }
> > +
> > +static WDT_ATTR(enable_reset, WDT_CTRL, WDT_CTRL_RESET_EN);
> > +static WDT_ATTR(enable_soft_ping, WDT_RELOAD_CTRL, WDT_RELOAD_PORT_EN);
> > +static WDT_ATTR(trigger_polarity, WDT_CTRL, WDT_CTRL_TRIG_POLARITY);
> > +static WDT_ATTR(keepalive_trigger_polarity, WDT_RELOAD_CTRL,
> > + WDT_RELOAD_TRIG_POLARITY);
> > +
> > +static ssize_t wdt_trig_show(struct device *dev,
> > + struct device_attribute *da,
> > + char *buf)
> > +{
> > + struct watchdog_device *wdd = dev_get_drvdata(dev);
> > + struct ni7018_wdt *wdt = watchdog_get_drvdata(wdd);
> > + struct ni7018_attr *attr = to_ni7018_attr(da);
> > + u8 control;
> > + size_t ret;
> > +
> > + mutex_lock(&wdt->lock);
> > +
> > + control = inb(wdt->io_base + attr->offset);
> > +
> > + mutex_unlock(&wdt->lock);
> > +
> > + if (control & attr->bit)
> > + ret = sprintf(buf, "trig%u\n", (control & attr->bit) - 1);
> > + else
> > + ret = sprintf(buf, "none\n");
> > +
> > + return ret;
> > +}
> > +
> > +static ssize_t wdt_trig_store(struct device *dev,
> > + struct device_attribute *da,
> > + const char *buf,
> > + size_t size)
> > +{
> > + struct watchdog_device *wdd = dev_get_drvdata(dev);
> > + struct ni7018_wdt *wdt = watchdog_get_drvdata(wdd);
> > + struct ni7018_attr *attr = to_ni7018_attr(da);
> > + unsigned long val;
> > + u8 control;
> > + int ret;
> > +
> > + if (!strncmp(buf, "trig", 4)) {
> > + ret = kstrtoul(buf + 4, 10, &val);
> > + if (ret)
> > + return ret;
> > +
> > + if (val < WDT_MIN_TRIG_NUM || val > WDT_MAX_TRIG_NUM)
> > + return -EINVAL;
> > +
> > + mutex_lock(&wdt->lock);
> > +
> > + control = inb(wdt->io_base + attr->offset);
> > + outb((control & ~attr->bit) | (val + 1),
> > + wdt->io_base + attr->offset);
> > +
> > + mutex_unlock(&wdt->lock);
> > +
> > + } else if (!strncmp(buf, "none", 4)) {
> > + mutex_lock(&wdt->lock);
> > +
> > + control = inb(wdt->io_base + attr->offset);
> > + outb(control & ~attr->bit, wdt->io_base + attr->offset);
> > +
> > + mutex_unlock(&wdt->lock);
> > +
> > + } else {
> > + return -EINVAL;
> > + }
> > +
> > + return size;
> > +}
> > +
> > +#define WDT_TRIG_ATTR(_name, _offset, _bit) \
> > + struct ni7018_attr dev_attr_##_name = { \
> > + .offset = _offset, \
> > + .bit = _bit, \
> > + .dev_attr = \
> > + __ATTR(_name, S_IWUSR | S_IRUGO, \
> > + wdt_trig_show, wdt_trig_store), \
> > + }
> > +
> > +static WDT_TRIG_ATTR(trigger, WDT_CTRL, WDT_CTRL_TRIG);
> > +static WDT_TRIG_ATTR(keepalive_trigger, WDT_RELOAD_CTRL, WDT_RELOAD_TRIG);
> > +
> > +static struct attribute *ni7018_wdt_attrs[] = {
> > + &dev_attr_enable_reset.dev_attr.attr,
> > + &dev_attr_enable_soft_ping.dev_attr.attr,
> > + &dev_attr_trigger_polarity.dev_attr.attr,
> > + &dev_attr_keepalive_trigger_polarity.dev_attr.attr,
> > + &dev_attr_trigger.dev_attr.attr,
> > + &dev_attr_keepalive_trigger.dev_attr.attr,
> > + NULL
> > +};
> > +ATTRIBUTE_GROUPS(ni7018_wdt);
> > +
> > +static int ni7018_add(struct acpi_device *device)
> > +{
> > + struct device *dev = &device->dev;
> > + struct watchdog_device *wdd;
> > + struct ni7018_wdt *wdt;
> > + acpi_status status;
> > + int ret;
> > +
> > + wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
> > + if (!wdt)
> > + return -ENOMEM;
> > +
> > + device->driver_data = wdt;
> > + wdt->dev = dev;
> > +
> > + status = acpi_walk_resources(device->handle, METHOD_NAME__CRS,
> > + ni7018_resources, wdt);
> > +
> > + if (ACPI_FAILURE(status) || wdt->io_base == 0) {
> > + dev_err(dev, "failed to get resources\n");
> > + return -ENODEV;
> > + }
> > +
> > + wdd = &wdt->wdd;
> > + wdd->info = &ni7018_wdd_info;
> > + wdd->ops = &ni7018_wdd_ops;
> > + wdd->min_timeout = WDT_MIN_TIMEOUT;
> > + wdd->max_timeout = WDT_MAX_TIMEOUT;
> > + wdd->timeout = WDT_DEFAULT_TIMEOUT;
> > + wdd->parent = dev;
> > + wdd->groups = ni7018_wdt_groups;
> > +
> > + mutex_init(&wdt->lock);
> > + watchdog_set_drvdata(wdd, wdt);
> > + watchdog_set_nowayout(wdd, nowayout);
> > +
> > + ret = watchdog_init_timeout(wdd, timeout, dev);
> > + if (ret)
> > + dev_err(dev, "unable to set timeout value, using default\n");
> > +
> > + /* Unlock WDT register */
> > + outb(UNLOCK, wdt->io_base + WDT_REG_LOCK);
> > +
> > + ret = watchdog_register_device(wdd);
> > + if (ret) {
> > + dev_err(dev, "failed to register watchdog\n");
> > + goto err_out;
> > + }
> > +
> > + dev_dbg(dev, "io_base=0x%04X, timeout=%d, nowayout=%d\n",
> > + wdt->io_base, timeout, nowayout);
> > + return 0;
> > +
> > +err_out:
> > + mutex_destroy(&wdt->lock);
> > + return ret;
> > +}
> > +
> > +static int ni7018_remove(struct acpi_device *device)
> > +{
> > + struct ni7018_wdt *wdt = acpi_driver_data(device);
> > +
> > + ni7018_stop(&wdt->wdd);
> > + watchdog_unregister_device(&wdt->wdd);
> > +
> > + /* Lock WDT register */
> > + outb(LOCK, wdt->io_base + WDT_REG_LOCK);
> > +
> > + mutex_destroy(&wdt->lock);
> > + return 0;
> > +}
> > +
> > +static const struct acpi_device_id ni7018_device_ids[] = {
> > + {"NIC7018", 0},
> > + {"", 0},
> > +};
> > +MODULE_DEVICE_TABLE(acpi, ni7018_device_ids);
> > +
> > +static struct acpi_driver ni7018_acpi_driver = {
> > + .name = KBUILD_MODNAME,
> > + .ids = ni7018_device_ids,
> > + .ops = {
> > + .add = ni7018_add,
> > + .remove = ni7018_remove,
> > + },
> > +};
> > +
> > +module_acpi_driver(ni7018_acpi_driver);
> > +
> > +MODULE_DESCRIPTION("NI 7018 Watchdog");
> > +MODULE_AUTHOR("Hui Chun Ong <hui.chun....@ni.com>");
> > +MODULE_LICENSE("GPL v2");
