Sender: Guenter Roeck <groeck7@gmail.com>
Subject: Re: [PATCH v5 3/4] watchdog: simatic-ipc-wdt: add new driver for
 Siemens Industrial PCs
To:     Hans de Goede <hdegoede@redhat.com>,
        Wim Van Sebroeck <wim@linux-watchdog.org>
Cc:     Srikanth Krishnakar <skrishnakar@gmail.com>,
        Jan Kiszka <jan.kiszka@siemens.com>,
        Gerd Haeussler <gerd.haeussler.ext@siemens.com>,
        Mark Gross <mgross@linux.intel.com>,
        Pavel Machek <pavel@ucw.cz>,
        Andy Shevchenko <andy.shevchenko@gmail.com>,
        Enrico Weigelt <lkml@metux.net>,
        Henning Schild <henning.schild@siemens.com>,
        linux-kernel@vger.kernel.org, linux-leds@vger.kernel.org,
        platform-driver-x86@vger.kernel.org, linux-watchdog@vger.kernel.org
References: <20211213120502.20661-1-henning.schild@siemens.com>
 <20211213120502.20661-4-henning.schild@siemens.com>
 <982a7065-f814-d9e8-8dfd-7546f7b9dc85@redhat.com>
From:   Guenter Roeck <linux@roeck-us.net>
Message-ID: <0f1a7dac-37d4-c055-d402-1af90811e712@roeck-us.net>
Date:   Wed, 15 Dec 2021 13:52:08 -0800
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On 12/15/21 12:56 PM, Hans de Goede wrote:
> Hi Wim, Guenter,
> 
> On 12/13/21 13:05, Henning Schild wrote:
>> This driver adds initial support for several devices from Siemens. It is
>> based on a platform driver introduced in an earlier commit.
>>
>> One of the supported machines does access a GPIO pin to enable the
>> watchdog. Here we poke GPIO memory because pinctrl does not come up.
>>
>> Signed-off-by: Henning Schild <henning.schild@siemens.com>
>> Reviewed-by: Guenter Roeck <linux@roeck-us.net>
> 
> I see that this patch #includes linux/platform_data/x86/simatic-ipc-base.h
> which gets added by patch 1/4.
> 
> Since this has already been reviewed, can I take this patch upstream
> through the pdx86 tree? Or shall I prepare an immutable branch with

Please go ahead and take the entire series.

Thanks,
Guenter

> patch 1 for you to merge ?
> 
> Regards,
> 
> Hans
> 
> 
> 
>> ---
>>   drivers/watchdog/Kconfig           |  11 ++
>>   drivers/watchdog/Makefile          |   1 +
>>   drivers/watchdog/simatic-ipc-wdt.c | 228 +++++++++++++++++++++++++++++
>>   3 files changed, 240 insertions(+)
>>   create mode 100644 drivers/watchdog/simatic-ipc-wdt.c
>>
>> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
>> index 9d222ba17ec6..1dc86eb1361a 100644
>> --- a/drivers/watchdog/Kconfig
>> +++ b/drivers/watchdog/Kconfig
>> @@ -1589,6 +1589,17 @@ config NIC7018_WDT
>>   	  To compile this driver as a module, choose M here: the module will be
>>   	  called nic7018_wdt.
>>   
>> +config SIEMENS_SIMATIC_IPC_WDT
>> +	tristate "Siemens Simatic IPC Watchdog"
>> +	depends on SIEMENS_SIMATIC_IPC
>> +	select WATCHDOG_CORE
>> +	help
>> +	  This driver adds support for several watchdogs found in Industrial
>> +	  PCs from Siemens.
>> +
>> +	  To compile this driver as a module, choose M here: the module will be
>> +	  called simatic-ipc-wdt.
>> +
>>   # M68K Architecture
>>   
>>   config M54xx_WATCHDOG
>> diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
>> index 2ee97064145b..31b931846e32 100644
>> --- a/drivers/watchdog/Makefile
>> +++ b/drivers/watchdog/Makefile
>> @@ -143,6 +143,7 @@ obj-$(CONFIG_NI903X_WDT) += ni903x_wdt.o
>>   obj-$(CONFIG_NIC7018_WDT) += nic7018_wdt.o
>>   obj-$(CONFIG_MLX_WDT) += mlx_wdt.o
>>   obj-$(CONFIG_KEEMBAY_WATCHDOG) += keembay_wdt.o
>> +obj-$(CONFIG_SIEMENS_SIMATIC_IPC_WDT) += simatic-ipc-wdt.o
>>   
>>   # M68K Architecture
>>   obj-$(CONFIG_M54xx_WATCHDOG) += m54xx_wdt.o
>> diff --git a/drivers/watchdog/simatic-ipc-wdt.c b/drivers/watchdog/simatic-ipc-wdt.c
>> new file mode 100644
>> index 000000000000..8bac793c63fb
>> --- /dev/null
>> +++ b/drivers/watchdog/simatic-ipc-wdt.c
>> @@ -0,0 +1,228 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * Siemens SIMATIC IPC driver for Watchdogs
>> + *
>> + * Copyright (c) Siemens AG, 2020-2021
>> + *
>> + * Authors:
>> + *  Gerd Haeussler <gerd.haeussler.ext@siemens.com>
>> + */
>> +
>> +#include <linux/device.h>
>> +#include <linux/errno.h>
>> +#include <linux/init.h>
>> +#include <linux/io.h>
>> +#include <linux/ioport.h>
>> +#include <linux/kernel.h>
>> +#include <linux/module.h>
>> +#include <linux/pci.h>
>> +#include <linux/platform_data/x86/simatic-ipc-base.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/sizes.h>
>> +#include <linux/util_macros.h>
>> +#include <linux/watchdog.h>
>> +
>> +#define WD_ENABLE_IOADR			0x62
>> +#define WD_TRIGGER_IOADR		0x66
>> +#define GPIO_COMMUNITY0_PORT_ID		0xaf
>> +#define PAD_CFG_DW0_GPP_A_23		0x4b8
>> +#define SAFE_EN_N_427E			0x01
>> +#define SAFE_EN_N_227E			0x04
>> +#define WD_ENABLED			0x01
>> +#define WD_TRIGGERED			0x80
>> +#define WD_MACROMODE			0x02
>> +
>> +#define TIMEOUT_MIN	2
>> +#define TIMEOUT_DEF	64
>> +#define TIMEOUT_MAX	64
>> +
>> +#define GP_STATUS_REG_227E	0x404D	/* IO PORT for SAFE_EN_N on 227E */
>> +
>> +static bool nowayout = WATCHDOG_NOWAYOUT;
>> +module_param(nowayout, bool, 0000);
>> +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
>> +		 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
>> +
>> +static struct resource gp_status_reg_227e_res =
>> +	DEFINE_RES_IO_NAMED(GP_STATUS_REG_227E, SZ_1, KBUILD_MODNAME);
>> +
>> +static struct resource io_resource_enable =
>> +	DEFINE_RES_IO_NAMED(WD_ENABLE_IOADR, SZ_1,
>> +			    KBUILD_MODNAME " WD_ENABLE_IOADR");
>> +
>> +static struct resource io_resource_trigger =
>> +	DEFINE_RES_IO_NAMED(WD_TRIGGER_IOADR, SZ_1,
>> +			    KBUILD_MODNAME " WD_TRIGGER_IOADR");
>> +
>> +/* the actual start will be discovered with pci, 0 is a placeholder */
>> +static struct resource mem_resource =
>> +	DEFINE_RES_MEM_NAMED(0, SZ_4, "WD_RESET_BASE_ADR");
>> +
>> +static u32 wd_timeout_table[] = {2, 4, 6, 8, 16, 32, 48, 64 };
>> +static void __iomem *wd_reset_base_addr;
>> +
>> +static int wd_start(struct watchdog_device *wdd)
>> +{
>> +	outb(inb(WD_ENABLE_IOADR) | WD_ENABLED, WD_ENABLE_IOADR);
>> +	return 0;
>> +}
>> +
>> +static int wd_stop(struct watchdog_device *wdd)
>> +{
>> +	outb(inb(WD_ENABLE_IOADR) & ~WD_ENABLED, WD_ENABLE_IOADR);
>> +	return 0;
>> +}
>> +
>> +static int wd_ping(struct watchdog_device *wdd)
>> +{
>> +	inb(WD_TRIGGER_IOADR);
>> +	return 0;
>> +}
>> +
>> +static int wd_set_timeout(struct watchdog_device *wdd, unsigned int t)
>> +{
>> +	int timeout_idx = find_closest(t, wd_timeout_table,
>> +				       ARRAY_SIZE(wd_timeout_table));
>> +
>> +	outb((inb(WD_ENABLE_IOADR) & 0xc7) | timeout_idx << 3, WD_ENABLE_IOADR);
>> +	wdd->timeout = wd_timeout_table[timeout_idx];
>> +	return 0;
>> +}
>> +
>> +static const struct watchdog_info wdt_ident = {
>> +	.options	= WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING |
>> +			  WDIOF_SETTIMEOUT,
>> +	.identity	= KBUILD_MODNAME,
>> +};
>> +
>> +static const struct watchdog_ops wdt_ops = {
>> +	.owner		= THIS_MODULE,
>> +	.start		= wd_start,
>> +	.stop		= wd_stop,
>> +	.ping		= wd_ping,
>> +	.set_timeout	= wd_set_timeout,
>> +};
>> +
>> +static void wd_secondary_enable(u32 wdtmode)
>> +{
>> +	u16 resetbit;
>> +
>> +	/* set safe_en_n so we are not just WDIOF_ALARMONLY */
>> +	if (wdtmode == SIMATIC_IPC_DEVICE_227E) {
>> +		/* enable SAFE_EN_N on GP_STATUS_REG_227E */
>> +		resetbit = inb(GP_STATUS_REG_227E);
>> +		outb(resetbit & ~SAFE_EN_N_227E, GP_STATUS_REG_227E);
>> +	} else {
>> +		/* enable SAFE_EN_N on PCH D1600 */
>> +		resetbit = ioread16(wd_reset_base_addr);
>> +		iowrite16(resetbit & ~SAFE_EN_N_427E, wd_reset_base_addr);
>> +	}
>> +}
>> +
>> +static int wd_setup(u32 wdtmode)
>> +{
>> +	unsigned int bootstatus = 0;
>> +	int timeout_idx;
>> +
>> +	timeout_idx = find_closest(TIMEOUT_DEF, wd_timeout_table,
>> +				   ARRAY_SIZE(wd_timeout_table));
>> +
>> +	if (inb(WD_ENABLE_IOADR) & WD_TRIGGERED)
>> +		bootstatus |= WDIOF_CARDRESET;
>> +
>> +	/* reset alarm bit, set macro mode, and set timeout */
>> +	outb(WD_TRIGGERED | WD_MACROMODE | timeout_idx << 3, WD_ENABLE_IOADR);
>> +
>> +	wd_secondary_enable(wdtmode);
>> +
>> +	return bootstatus;
>> +}
>> +
>> +static struct watchdog_device wdd_data = {
>> +	.info = &wdt_ident,
>> +	.ops = &wdt_ops,
>> +	.min_timeout = TIMEOUT_MIN,
>> +	.max_timeout = TIMEOUT_MAX
>> +};
>> +
>> +static int simatic_ipc_wdt_probe(struct platform_device *pdev)
>> +{
>> +	struct simatic_ipc_platform *plat = pdev->dev.platform_data;
>> +	struct device *dev = &pdev->dev;
>> +	struct resource *res;
>> +
>> +	switch (plat->devmode) {
>> +	case SIMATIC_IPC_DEVICE_227E:
>> +		if (!devm_request_region(dev, gp_status_reg_227e_res.start,
>> +					 resource_size(&gp_status_reg_227e_res),
>> +					 KBUILD_MODNAME)) {
>> +			dev_err(dev,
>> +				"Unable to register IO resource at %pR\n",
>> +				&gp_status_reg_227e_res);
>> +			return -EBUSY;
>> +		}
>> +		fallthrough;
>> +	case SIMATIC_IPC_DEVICE_427E:
>> +		wdd_data.parent = dev;
>> +		break;
>> +	default:
>> +		return -EINVAL;
>> +	}
>> +
>> +	if (!devm_request_region(dev, io_resource_enable.start,
>> +				 resource_size(&io_resource_enable),
>> +				 io_resource_enable.name)) {
>> +		dev_err(dev,
>> +			"Unable to register IO resource at %#x\n",
>> +			WD_ENABLE_IOADR);
>> +		return -EBUSY;
>> +	}
>> +
>> +	if (!devm_request_region(dev, io_resource_trigger.start,
>> +				 resource_size(&io_resource_trigger),
>> +				 io_resource_trigger.name)) {
>> +		dev_err(dev,
>> +			"Unable to register IO resource at %#x\n",
>> +			WD_TRIGGER_IOADR);
>> +		return -EBUSY;
>> +	}
>> +
>> +	if (plat->devmode == SIMATIC_IPC_DEVICE_427E) {
>> +		res = &mem_resource;
>> +
>> +		/* get GPIO base from PCI */
>> +		res->start = simatic_ipc_get_membase0(PCI_DEVFN(0x1f, 1));
>> +		if (res->start == 0)
>> +			return -ENODEV;
>> +
>> +		/* do the final address calculation */
>> +		res->start = res->start + (GPIO_COMMUNITY0_PORT_ID << 16) +
>> +			     PAD_CFG_DW0_GPP_A_23;
>> +		res->end += res->start;
>> +
>> +		wd_reset_base_addr = devm_ioremap_resource(dev, res);
>> +		if (IS_ERR(wd_reset_base_addr))
>> +			return PTR_ERR(wd_reset_base_addr);
>> +	}
>> +
>> +	wdd_data.bootstatus = wd_setup(plat->devmode);
>> +	if (wdd_data.bootstatus)
>> +		dev_warn(dev, "last reboot caused by watchdog reset\n");
>> +
>> +	watchdog_set_nowayout(&wdd_data, nowayout);
>> +	watchdog_stop_on_reboot(&wdd_data);
>> +	return devm_watchdog_register_device(dev, &wdd_data);
>> +}
>> +
>> +static struct platform_driver simatic_ipc_wdt_driver = {
>> +	.probe = simatic_ipc_wdt_probe,
>> +	.driver = {
>> +		.name = KBUILD_MODNAME,
>> +	},
>> +};
>> +
>> +module_platform_driver(simatic_ipc_wdt_driver);
>> +
>> +MODULE_LICENSE("GPL v2");
>> +MODULE_ALIAS("platform:" KBUILD_MODNAME);
>> +MODULE_AUTHOR("Gerd Haeussler <gerd.haeussler.ext@siemens.com>");
>>
>