Hi Guenter,
>> +
>> +struct cgbc_wdt_cmd_cfg {
>> + u8 cmd;
>> + u8 mode;
>> + u8 action;
>> + u8 timeout1[3];
>> + u8 timeout2[3];
>> + u8 reserved[3];
>> + u8 delay[3];
>> +} __packed;
>> +
>> +static_assert(sizeof(struct cgbc_wdt_cmd_cfg) == 15);
>
> static_assert() is declared in linux/build_bug.h. Please include all
> necessary include files explicitly and do not depend on indirect includes.
Fixed in next iteration.
>
>> +
>> +static int cgbc_wdt_start(struct watchdog_device *wdd)
>> +{
>> + struct cgbc_wdt_data *wdt_data = watchdog_get_drvdata(wdd);
>
> Unusual way to get wdt_data instead of using container_of().
> Any special reason ?
No special reason, I saw that watchdog_get_drvdata() was often used in
watchdog drivers (more than container_of()) to get wdt_data.
But I can use container_of() if you think I should.
>
>> + struct cgbc_device_data *cgbc = wdt_data->cgbc;
>> + unsigned int timeout1 = (wdd->timeout - wdd->pretimeout) * 1000;
>> + unsigned int timeout2 = wdd->pretimeout * 1000;
>> + u8 action;
>> +
>> + struct cgbc_wdt_cmd_cfg cmd_start = {
>> + .cmd = CGBC_WDT_CMD_INIT,
>> + .mode = CGBC_WDT_MODE_SINGLE_EVENT,
>> + .timeout1[0] = (u8)timeout1,
>> + .timeout1[1] = (u8)(timeout1 >> 8),
>> + .timeout1[2] = (u8)(timeout1 >> 16),
>> + .timeout2[0] = (u8)timeout2,
>> + .timeout2[1] = (u8)(timeout2 >> 8),
>> + .timeout2[2] = (u8)(timeout2 >> 16),
>> + };
>> +
>> + if (wdd->pretimeout) {
>> + action = 2;
>> + action |= wdt_data->pretimeout_action << 2;
>> + action |= wdt_data->timeout_action << 4;
>> + } else {
>> + action = 1;
>> + action |= wdt_data->timeout_action << 2;
>> + }
>> +
>> + cmd_start.action = action;
>> +
>> + return cgbc_command(cgbc, &cmd_start, sizeof(cmd_start), NULL, 0, NULL);
>> +}
>> +
>> +static int cgbc_wdt_stop(struct watchdog_device *wdd)
>> +{
>> + struct cgbc_wdt_data *wdt_data = watchdog_get_drvdata(wdd);
>> + struct cgbc_device_data *cgbc = wdt_data->cgbc;
>> + struct cgbc_wdt_cmd_cfg cmd_stop = {
>> + .cmd = CGBC_WDT_CMD_INIT,
>> + .mode = CGBC_WDT_DISABLE,
>> + };
>> +
>> + return cgbc_command(cgbc, &cmd_stop, sizeof(cmd_stop), NULL, 0, NULL);
>> +}
>> +
>> +static int cgbc_wdt_keepalive(struct watchdog_device *wdd)
>> +{
>> + struct cgbc_wdt_data *wdt_data = watchdog_get_drvdata(wdd);
>> + struct cgbc_device_data *cgbc = wdt_data->cgbc;
>> + u8 cmd_ping = CGBC_WDT_CMD_TRIGGER;
>> +
>> + return cgbc_command(cgbc, &cmd_ping, sizeof(cmd_ping), NULL, 0, NULL);
>> +}
>> +
>> +static int cgbc_wdt_set_pretimeout(struct watchdog_device *wdd,
>> + unsigned int pretimeout)
>> +{
>> + struct cgbc_wdt_data *wdt_data = watchdog_get_drvdata(wdd);
>> +
>> + wdd->pretimeout = pretimeout;
>> + wdt_data->pretimeout_action = ACTION_SMI;
>> +
>> + if (watchdog_active(wdd))
>> + return cgbc_wdt_start(wdd);
>> +
>> + return 0;
>> +}
>> +
>> +static int cgbc_wdt_set_timeout(struct watchdog_device *wdd,
>> + unsigned int timeout)
>> +{
>> + struct cgbc_wdt_data *wdt_data = watchdog_get_drvdata(wdd);
>> +
>> + if (timeout < wdd->pretimeout) {
>> + dev_warn(wdd->parent, "timeout <= pretimeout. Setting pretimeout to zero\n");
>
> That is a normal condition which does not warrant a log message.
> Also see drivers/watchdog/watchdog_dev.c around line 385.
Fixed in next iteration.
>
>> + wdd->pretimeout = 0;
>> + }
>> +
>> + wdd->timeout = timeout;
>> + wdt_data->timeout_action = ACTION_RESET;
>
> Both timeout_action and pretimeout_action are set statically.
> What is the point of doing that instead of just using
> ACTION_RESET and ACTION_SMI as needed irectly ?
Yes indeed, using ACTION_RESET and ACTION_SMI directly in
cgbc_wdt_start() makes the code smaller.
>
>> +
>> + if (watchdog_active(wdd))
>> + return cgbc_wdt_start(wdd);
>> +
>> + return 0;
>> +}
>> +
>> +static const struct watchdog_info cgbc_wdt_info = {
>> + .identity = "CGBC Watchdog",
>> + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
>> + WDIOF_MAGICCLOSE | WDIOF_PRETIMEOUT
>> +};
>> +
>> +static const struct watchdog_ops cgbc_wdt_ops = {
>> + .owner = THIS_MODULE,
>> + .start = cgbc_wdt_start,
>> + .stop = cgbc_wdt_stop,
>> + .ping = cgbc_wdt_keepalive,
>> + .set_timeout = cgbc_wdt_set_timeout,
>> + .set_pretimeout = cgbc_wdt_set_pretimeout,
>> +};
>> +
>> +static int cgbc_wdt_probe(struct platform_device *pdev)
>> +{
>> + struct cgbc_device_data *cgbc = dev_get_drvdata(pdev->dev.parent);
>> + struct device *dev = &pdev->dev;
>> + struct cgbc_wdt_data *wdt_data;
>> + struct watchdog_device *wdd;
>> + int ret;
>> +
>> + wdt_data = devm_kzalloc(dev, sizeof(*wdt_data), GFP_KERNEL);
>
> devm_kzalloc() is declared in linux/device.h. Again, please include all
> necessary include files explicitly.
Fixed in next iteration.
>
>> + if (!wdt_data)
>> + return -ENOMEM;
>> +
>> + wdt_data->cgbc = cgbc;
>> + wdd = &wdt_data->wdd;
>> + wdd->parent = dev;
>> +
>
> No limits ? That is unusual. Are you sure the driver accepts all
> timeouts from 0 to UINT_MAX ?
Yes limits are needed.
For next iteration I added 1s as min_timeout (which seems to be the
usual value, and it is accepted by the hardware), and a max_timeout.
>
>> + wdd->info = &cgbc_wdt_info;
>> + wdd->ops = &cgbc_wdt_ops;
>> +
>> + watchdog_set_drvdata(wdd, wdt_data);
>> + watchdog_set_nowayout(wdd, nowayout);
>> +
>> + cgbc_wdt_set_timeout(wdd, timeout);
>> + cgbc_wdt_set_pretimeout(wdd, pretimeout);
>
> The more common approach would be to set default limits in wdd->{timout,pretimeout}
> and only override the values if needed, ie if provided using module parameters.
> That implies initializing the module parameters with 0. YOur call, though.
Ok.
For next iteration I added limits (min_timeout, max_timeout), the
timeout module parameter is set to 0 by default, and
watchdog_init_timeout() is called in the probe.
>
>> +
>> + platform_set_drvdata(pdev, wdt_data);
>> + watchdog_stop_on_reboot(wdd);
>> + watchdog_stop_on_unregister(wdd);
>> +
>> + ret = devm_watchdog_register_device(dev, wdd);
>> + if (ret)
>> + return ret;
>> +
>> + return 0;
>
> Why not just
> return devm_watchdog_register_device(dev, wdd);
> ?
I don't know :)
Fixed in the next iteration.
Thanks for the review !!
Thomas.
