Re: [PATCH v2 3/4] watchdog: simatic-ipc-wdt: add new driver for Siemens Industrial PCs

Guenter Roeck
2021-03-15T15:11:15Z

On 3/15/21 2:57 AM, 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.
>
> Signed-off-by: Henning Schild <henning.schild@siemens.com>

Reviewed-by: Guenter Roeck <linux@roeck-us.net>

> ---
> drivers/watchdog/Kconfig | 11 ++
> drivers/watchdog/Makefile | 1 +
> drivers/watchdog/simatic-ipc-wdt.c | 215 +++++++++++++++++++++++++++++
> 3 files changed, 227 insertions(+)
> create mode 100644 drivers/watchdog/simatic-ipc-wdt.c
>
> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
> index 1fe0042a48d2..948497eb4bef 100644
> --- a/drivers/watchdog/Kconfig
> +++ b/drivers/watchdog/Kconfig
> @@ -1575,6 +1575,17 @@ 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 f3a6540e725e..7f5c73ec058c 100644
> --- a/drivers/watchdog/Makefile
> +++ b/drivers/watchdog/Makefile
> @@ -142,6 +142,7 @@ 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..f0f948968db3
> --- /dev/null
> +++ b/drivers/watchdog/simatic-ipc-wdt.c
> @@ -0,0 +1,215 @@
> +// 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 =
> + DEFINE_RES_IO_NAMED(WD_ENABLE_IOADR, SZ_1,
> + KBUILD_MODNAME " WD_ENABLE_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 = inw(GP_STATUS_REG_227E);
> + outw(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.start,
> + resource_size(&io_resource),
> + io_resource.name)) {
> + dev_err(dev,
> + "Unable to register IO resource at %#x\n",
> + WD_ENABLE_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 wdt_driver = {
> + .probe = simatic_ipc_wdt_probe,
> + .driver = {
> + .name = KBUILD_MODNAME,
> + },
> +};
> +
> +module_platform_driver(wdt_driver);
> +
> +MODULE_LICENSE("GPL v2");
> +MODULE_ALIAS("platform:" KBUILD_MODNAME);
> +MODULE_AUTHOR("Gerd Haeussler <gerd.haeussler.ext@siemens.com>");
>