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Message-ID: <557A0605.3050609@roeck-us.net>
Date: Thu, 11 Jun 2015 15:04:53 -0700
From: Guenter Roeck <linux@...ck-us.net>
To: Christian Gmeiner <christian.gmeiner@...il.com>,
linux-kernel@...r.kernel.org
CC: sameo@...ux.intel.com, lee.jones@...aro.org, wsa@...-dreams.de,
jdelvare@...e.de, linux-i2c@...r.kernel.org, wim@...ana.be,
linux-watchdog@...r.kernel.org, jingoohan1@...il.com,
Sascha Hauer <s.hauer@...gutronix.de>
Subject: Re: [PATCH 3/4] watchdog: Add Congatec CGEB watchdog driver
On 06/11/2015 01:48 PM, Christian Gmeiner wrote:
> From: Sascha Hauer <s.hauer@...gutronix.de>
>
> This driver provides support for the CGEB watchdog found on some
> Congatec x86 modules.
>
> Signed-off-by: Sascha Hauer <s.hauer@...gutronix.de>
> Signed-off-by: Christian Gmeiner <christian.gmeiner@...il.com>
Hi Christian,
comments inline.
Thanks,
Guenter
> ---
> drivers/watchdog/Kconfig | 10 ++
> drivers/watchdog/Makefile | 3 +
> drivers/watchdog/congatec_cgeb_watchdog.c | 181 ++++++++++++++++++++++++++++++
> 3 files changed, 194 insertions(+)
> create mode 100644 drivers/watchdog/congatec_cgeb_watchdog.c
>
> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
> index e5e7c55..bb93cbc 100644
> --- a/drivers/watchdog/Kconfig
> +++ b/drivers/watchdog/Kconfig
> @@ -1088,6 +1088,16 @@ config SBC_EPX_C3_WATCHDOG
> To compile this driver as a module, choose M here: the
> module will be called sbc_epx_c3.
>
> +config CONGATEC_CGEB_WATCHDOG
> + tristate "Congatec CGEB watchdog"
> + depends on MFD_CONGATEC_CGEB
> + ---help---
> + This driver provides support for the watchdogs found on Congatec
> + modules with the CGEB BIOS interface.
> +
> + To compile this driver as a module, choose M here: the
> + module will be called congatec_cgeb_wdt.
> +
> # M32R Architecture
>
> # M68K Architecture
> diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
> index 5c19294..b24fd09 100644
> --- a/drivers/watchdog/Makefile
> +++ b/drivers/watchdog/Makefile
> @@ -171,6 +171,9 @@ obj-$(CONFIG_SH_WDT) += shwdt.o
> obj-$(CONFIG_WATCHDOG_RIO) += riowd.o
> obj-$(CONFIG_WATCHDOG_CP1XXX) += cpwd.o
>
> +# X86 Architecture
> +obj-$(CONFIG_CONGATEC_CGEB_WATCHDOG) += congatec_cgeb_watchdog.o
> +
No need for a second set of x86 drivers. Please add to the existing set.
Also, please align with other '+='.
> # XTENSA Architecture
>
> # Xen
> diff --git a/drivers/watchdog/congatec_cgeb_watchdog.c b/drivers/watchdog/congatec_cgeb_watchdog.c
> new file mode 100644
> index 0000000..e4523c4
> --- /dev/null
> +++ b/drivers/watchdog/congatec_cgeb_watchdog.c
> @@ -0,0 +1,181 @@
> +/*
> + * CGEB watchdog driver
> + *
> + * (c) 2011 Sascha Hauer, Pengutronix
2011 ?
> + *
> + * 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; version 2 of the License.
> + *
> + * 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/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/watchdog.h>
> +#include <linux/mfd/congatec-cgeb.h>
> +
> +#define CGOS_WDOG_MODE_REBOOT_PC 0
> +#define CGOS_WDOG_MODE_RESTART_OS 1
> +#define CGOS_WDOG_MODE_STAGED 0x80
> +
> +#define CGOS_WDOG_OPMODE_DISABLED 0
> +#define CGOS_WDOG_OPMODE_ONETIME_TRIG 1
> +#define CGOS_WDOG_OPMODE_SINGLE_EVENT 2
> +#define CGOS_WDOG_OPMODE_EVENT_REPEAT 3
> +
> +#define CGOS_WDOG_EVENT_INT 0 /* NMI/IRQ */
> +#define CGOS_WDOG_EVENT_SCI 1 /* SMI/SCI */
> +#define CGOS_WDOG_EVENT_RST 2 /* system reset */
> +#define CGOS_WDOG_EVENT_BTN 3 /* power button */
> +
> +#define CGOS_WDOG_EVENT_MAX_STAGES 3
> +
Please use tabs after the defines.
#define CGOS_WDOG_MODE_REBOOT_PC 0
#define CGOS_WDOG_MODE_RESTART_OS 1
#define CGOS_WDOG_MODE_STAGED 0x80
#define CGOS_WDOG_OPMODE_DISABLED 0
#define CGOS_WDOG_OPMODE_ONETIME_TRIG 1
#define CGOS_WDOG_OPMODE_SINGLE_EVENT 2
#define CGOS_WDOG_OPMODE_EVENT_REPEAT 3
and so on.
> +struct cgeb_watchdog_stage {
> + unsigned long timeout;
> + unsigned long event;
> +};
> +
> +struct cgeb_watchdog_config {
> + unsigned long size;
> + unsigned long timeout; /* not used in staged mode */
> + unsigned long delay;
> + unsigned long mode;
> + /* optional parameters for staged watchdog */
> + unsigned long op_mode;
> + unsigned long stage_count;
> + struct cgeb_watchdog_stage stages[CGOS_WDOG_EVENT_MAX_STAGES];
> +};
> +
Since this is passed on to cgeb_call, shoul it be part of an API
defined elsewhere ?
Also, I am a bit concerned about the use of 'unsigned long'.
If this is part of an ABI to the BIOS, shouldn't it be u32 ?
Sure, the driver is currently limited to X64_32, but that doesn't
mean we have to make it extra difficult to port it to X86_64
if that is ever asked for.
> +struct cgeb_watchdog_priv {
> + struct cgeb_board_data *board;
> + struct watchdog_device wdd;
> + unsigned int timeout_s;
> + int unit;
> +};
> +
> +static struct watchdog_info cgeb_wdd_info = {
> + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
> + .firmware_version = 0,
No need to initialize static variables with 0.
> + .identity = "cgeb watchdog",
> +};
> +
Please move the above next to the probe function.
> +static unsigned int watchdog_set_config(struct cgeb_watchdog_priv *priv,
> + unsigned int timeout_s)
> +{
> + struct cgeb_board_data *board = priv->board;
> + struct cgeb_watchdog_config wdi;
> + struct cgeb_function_parameters fps;
> +
= { 0 };
> + memset(&wdi, 0, sizeof(wdi));
> + memset(&fps, 0, sizeof(fps));
would be identical to the memset.
> +
> + fps.unit = priv->unit;
> + fps.iptr = &wdi;
> +
> + wdi.timeout = timeout_s * 1000;
> + wdi.delay = 0;
Already set to 0.
> + wdi.size = sizeof(wdi);
> + wdi.mode = CGOS_WDOG_MODE_REBOOT_PC;
> +
> + return cgeb_call(board, &fps, CgebWDogSetConfig);
> +}
> +
> +static int cgeb_watchdog_start(struct watchdog_device *wdd)
> +{
> + struct cgeb_watchdog_priv *priv = watchdog_get_drvdata(wdd);
> +
> + return watchdog_set_config(priv, priv->timeout_s);
> +}
> +
> +static int cgeb_watchdog_stop(struct watchdog_device *wdd)
> +{
> + struct cgeb_watchdog_priv *priv = watchdog_get_drvdata(wdd);
> +
> + return watchdog_set_config(priv, 0);
> +}
> +
> +static int cgeb_watchdog_set_timeout(struct watchdog_device *wdd,
> + unsigned int timeout_s)
Please align continuation lines with '('.
> +{
> + struct cgeb_watchdog_priv *priv = watchdog_get_drvdata(wdd);
> +
> + if (!timeout_s)
> + return -EINVAL;
Unnecessary, checked by infrastructure.
> +
> + priv->timeout_s = timeout_s;
> +
You also need to set wdd->timeout. It also seems to me that
priv->timeout_s is not really necessary.
> + return 0;
> +}
> +
> +struct watchdog_ops cgeb_watchdog_ops = {
> + .start = cgeb_watchdog_start,
> + .stop = cgeb_watchdog_stop,
> + .set_timeout = cgeb_watchdog_set_timeout,
> +};
> +
> +static int cgeb_watchdog_probe(struct platform_device *pdev)
> +{
> + struct cgeb_watchdog_priv *priv;
> + struct cgeb_pdata *pdata = pdev->dev.platform_data;
> + int ret;
> +
> + dev_info(&pdev->dev, "registering\n");
Unnecessary noise.
> +
> + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
> + if (!priv)
> + return -ENOMEM;
> +
> + priv->wdd.ops = &cgeb_watchdog_ops;
> + priv->wdd.info = &cgeb_wdd_info;
> + priv->wdd.min_timeout = 1;
> + priv->wdd.max_timeout = 3600;
> + priv->board = pdata->board;
You should check if pdata == NULL and either use defaults
in that case or bail out.
> + priv->unit = pdata->unit;
> +
> + watchdog_set_drvdata(&priv->wdd, priv);
> + platform_set_drvdata(pdev, priv);
> +
> + ret = watchdog_register_device(&priv->wdd);
> + if (ret)
> + return ret;
> +
> + return 0;
just
return watchdog_register_device(&priv->wdd);
> +}
> +
> +static int cgeb_watchdog_remove(struct platform_device *pdev)
> +{
> + struct cgeb_watchdog_priv *priv = platform_get_drvdata(pdev);
> +
> + watchdog_unregister_device(&priv->wdd);
> +
> + return 0;
> +}
> +
> +static struct platform_driver cgeb_watchdog_driver = {
> + .probe = cgeb_watchdog_probe,
> + .remove = __exit_p(cgeb_watchdog_remove),
> + .driver = {
> + .name = "cgeb-watchdog",
> + .owner = THIS_MODULE,
AFAIK .owner is no longer necessary.
> + },
> +};
> +
> +static int __init cgeb_watchdog_driver_init(void)
> +{
> + return platform_driver_register(&cgeb_watchdog_driver);
> +}
> +
> +static void __exit cgeb_watchdog_driver_exit(void)
> +{
> + platform_driver_unregister(&cgeb_watchdog_driver);
> +}
> +
> +module_init(cgeb_watchdog_driver_init);
> +module_exit(cgeb_watchdog_driver_exit);
module_platform_driver(cgeb_watchdog_driver);
> +
> +MODULE_AUTHOR("Sascha Hauer <s.hauer@...gutronix.de>");
> +MODULE_DESCRIPTION("cgeb watchdog driver");
> +MODULE_LICENSE("GPL");
>
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