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    SubjectRe: [PATCH RFC] watchdog: add a new driver for VIA chipsets
    Wolfram Sang <w.sang@pengutronix.de> wrote:

    > On Tue, Nov 22, 2011 at 12:17:13PM +0100, Marc Vertes wrote:
    > > Add a new driver for the hardware watchdog timer on VIA chipsets.
    > > Tested on a Artigo A1100, VX855 chipset.
    > >
    > > Signed-off-by: Marc Vertes <marc.vertes@sigfox.com>
    >
    > New watchdog drivers should use the framework. Have a look at
    > Documentation/watchdog/convert_drivers_to_kernel_api.txt for a guide. It
    > is mainly removing code, though.
    >
    Here it is:
    ---
    Add a new driver for the hardware watchdog timer on VIA chipsets.
    This driver uses the new watchdog framework.
    Tested on a Artigo A1100, VX855 chipset.

    Signed-off-by: Marc Vertes <marc.vertes@sigfox.com>
    ---
    Kconfig | 14 ++++++
    Makefile | 1
    via_wdt.c | 134 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
    3 files changed, 149 insertions(+)
    --- linux-3.2-rc2/drivers/watchdog/Makefile.orig 2011-11-15 18:02:59.000000000 +0100
    +++ linux-3.2-rc2/drivers/watchdog/Makefile 2011-11-18 18:13:36.594534635 +0100
    @@ -100,6 +100,7 @@ obj-$(CONFIG_SBC7240_WDT) += sbc7240_wdt
    obj-$(CONFIG_CPU5_WDT) += cpu5wdt.o
    obj-$(CONFIG_SMSC_SCH311X_WDT) += sch311x_wdt.o
    obj-$(CONFIG_SMSC37B787_WDT) += smsc37b787_wdt.o
    +obj-$(CONFIG_VIA_WDT) += via_wdt.o
    obj-$(CONFIG_W83627HF_WDT) += w83627hf_wdt.o
    obj-$(CONFIG_W83697HF_WDT) += w83697hf_wdt.o
    obj-$(CONFIG_W83697UG_WDT) += w83697ug_wdt.o
    --- linux-3.2-rc2/drivers/watchdog/via_wdt.c.orig 2011-11-18 18:14:45.358174874 +0100
    +++ linux-3.2-rc2/drivers/watchdog/via_wdt.c 2011-11-22 17:20:05.531757353 +0100
    @@ -0,0 +1,134 @@
    +/*
    + * VIA Chipset Watchdog Driver
    + *
    + * Copyright (C) 2011 Sigfox
    + * License terms: GNU General Public License (GPL) version 2
    + * Author: Marc Vertes <marc.vertes@sigfox.com>
    + * Based on a preliminary version from Harald Welte <HaraldWelte@viatech.com>
    + *
    + * The only way to activate the watchdog timer or to set its period is
    + * through BIOS setup.
    + */
    +#include <linux/device.h>
    +#include <linux/io.h>
    +#include <linux/module.h>
    +#include <linux/pci.h>
    +#include <linux/watchdog.h>
    +
    +#define VIA_WDT_MB_OFFSET 0xe8 /* memory base offset */
    +#define VIA_WDT_TRIGGER 0x80 /* start a new countdown */
    +#define VIA_WDT_FIRED 0x02 /* set if last restart was caused
    + by expired watchdog timer */
    +
    +static int wdt_start(struct watchdog_device *wdev)
    +{
    + /* Nothing to do. The watchdog can only be started by the BIOS. */
    + return 0;
    +}
    +
    +static int wdt_stop(struct watchdog_device *wdev)
    +{
    + /* Nothing to do. The watchdog can not be stopped. */
    + return 0;
    +}
    +
    +static int wdt_ping(struct watchdog_device *wdev)
    +{
    + void __iomem *wdt_mem = watchdog_get_drvdata(wdev);
    + unsigned int res = readl(wdt_mem); /* get status bits */
    +
    + writel(res | VIA_WDT_TRIGGER, wdt_mem);
    + return 0;
    +}
    +
    +static struct watchdog_info wdt_info = {
    + .identity = "VIA watchdog",
    + .options = WDIOF_CARDRESET,
    +};
    +
    +static struct watchdog_ops wdt_ops = {
    + .owner = THIS_MODULE,
    + .start = wdt_start,
    + .stop = wdt_stop,
    + .ping = wdt_ping,
    +};
    +
    +static struct watchdog_device wdt_dev = {
    + .info = &wdt_info,
    + .ops = &wdt_ops,
    +};
    +
    +static int __devinit wdt_probe(struct pci_dev *pdev,
    + const struct pci_device_id *ent)
    +{
    + unsigned int mmio = 0;
    + void __iomem *wdt_mem;
    + int ret;
    +
    + if (pci_enable_device(pdev)) {
    + dev_err(&pdev->dev, "cannot enable PCI device\n");
    + return -ENODEV;
    + }
    + pci_read_config_dword(pdev, VIA_WDT_MB_OFFSET, &mmio);
    + dev_info(&pdev->dev, "VIA Chipset watchdog MMIO: %x\n", mmio);
    + if (mmio == 0) {
    + dev_err(&pdev->dev, "watchdog timer is not enabled in BIOS\n");
    + return -ENODEV;
    + }
    + wdt_mem = ioremap(mmio, 8);
    + if (wdt_mem == NULL) {
    + dev_err(&pdev->dev, "cannot remap VIA wdt mmio registers\n");
    + return -ENODEV;
    + }
    + ret = watchdog_register_device(&wdt_dev);
    + if (ret)
    + return ret;
    + watchdog_set_drvdata(&wdt_dev, wdt_mem);
    + if (readl(wdt_mem) & VIA_WDT_FIRED) {
    + wdt_dev.bootstatus |= WDIOF_CARDRESET;
    + dev_notice(&pdev->dev, "restarted by expired watchdog\n");
    + }
    + return 0;
    +}
    +
    +static void __devexit wdt_remove(struct pci_dev *dev)
    +{
    + void __iomem *wdt_mem = watchdog_get_drvdata(&wdt_dev);
    +
    + watchdog_unregister_device(&wdt_dev);
    + iounmap(wdt_mem);
    +}
    +
    +/*
    + * The driver has not been tested yet on CX700 and VX800.
    + */
    +DEFINE_PCI_DEVICE_TABLE(wdt_pci_table) = {
    + { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_CX700) },
    + { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VX800) },
    + { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VX855) },
    + { 0 }
    +};
    +
    +static struct pci_driver wdt_driver = {
    + .name = "via_wdt",
    + .id_table = wdt_pci_table,
    + .probe = wdt_probe,
    + .remove = __devexit_p(wdt_remove),
    +};
    +
    +static int __init wdt_init(void)
    +{
    + return pci_register_driver(&wdt_driver);
    +}
    +
    +static void __exit wdt_exit(void)
    +{
    + pci_unregister_driver(&wdt_driver);
    +}
    +
    +module_init(wdt_init);
    +module_exit(wdt_exit);
    +
    +MODULE_AUTHOR("Marc Vertes");
    +MODULE_DESCRIPTION("Driver for watchdog timer on VIA chipset");
    +MODULE_LICENSE("GPL");
    --- linux-3.2-rc2/drivers/watchdog/Kconfig.orig 2011-11-15 18:02:59.000000000 +0100
    +++ linux-3.2-rc2/drivers/watchdog/Kconfig 2011-11-22 16:39:38.175325620 +0100
    @@ -779,6 +779,20 @@ config SMSC37B787_WDT

    Most people will say N.

    +config VIA_WDT
    + tristate "VIA Watchdog Timer"
    + depends on X86
    + select WATCHDOG_CORE
    + ---help---
    + This is the driver for the hardware watchdog timer on VIA
    + southbridge chipset CX700, VX800, VX855. Watchdog setup
    + in BIOS is required.
    +
    + To compile this driver as a module, choose M here; the module
    + will be called via_wdt.
    +
    + Most people will say N.
    +
    config W83627HF_WDT
    tristate "W83627HF/W83627DHG Watchdog Timer"
    depends on X86

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