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    SubjectRe: [v3,3/5] watchdog: iTCO_wdt: Add PMC specific noreboot update api
    On Fri, Mar 17, 2017 at 07:06:20PM -0700, Kuppuswamy Sathyanarayanan wrote:
    > In some SOCs, setting noreboot bit needs modification to
    > PMC GC registers. But not all PMC drivers allow other drivers
    > to memory map their GC region. This could create mem request
    > conflict in watchdog driver. So this patch adds facility to allow
    > PMC drivers to pass noreboot update function to watchdog
    > drivers via platform data.
    >
    > Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>

    Not entirely happy, but I don't have a better idea either.

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

    > ---
    > drivers/watchdog/iTCO_wdt.c | 28 +++++++++++++++++++---------
    > include/linux/platform_data/itco_wdt.h | 1 +
    > 2 files changed, 20 insertions(+), 9 deletions(-)
    >
    > Changes since v2:
    > * Removed use of PMC API's directly in watchdog driver.
    > * Added update_noreboot_flag to handle no IPC PMC compatibility
    > issue mentioned by Guenter.
    >
    > diff --git a/drivers/watchdog/iTCO_wdt.c b/drivers/watchdog/iTCO_wdt.c
    > index 3d0abc0..7c34259 100644
    > --- a/drivers/watchdog/iTCO_wdt.c
    > +++ b/drivers/watchdog/iTCO_wdt.c
    > @@ -100,6 +100,8 @@ struct iTCO_wdt_private {
    > */
    > struct resource *gcs_pmc_res;
    > unsigned long __iomem *gcs_pmc;
    > + /* pmc specific api to update noreboot flag */
    > + int (*update_noreboot_flag)(bool status);
    > /* the lock for io operations */
    > spinlock_t io_lock;
    > /* the PCI-device */
    > @@ -176,9 +178,13 @@ static void iTCO_wdt_set_NO_REBOOT_bit(struct iTCO_wdt_private *p)
    >
    > /* Set the NO_REBOOT bit: this disables reboots */
    > if (p->iTCO_version >= 2) {
    > - val32 = readl(p->gcs_pmc);
    > - val32 |= no_reboot_bit(p);
    > - writel(val32, p->gcs_pmc);
    > + if (p->update_noreboot_flag)
    > + p->update_noreboot_flag(1);
    > + else {
    > + val32 = readl(p->gcs_pmc);
    > + val32 |= no_reboot_bit(p);
    > + writel(val32, p->gcs_pmc);
    > + }
    > } else if (p->iTCO_version == 1) {
    > pci_read_config_dword(p->pci_dev, 0xd4, &val32);
    > val32 |= no_reboot_bit(p);
    > @@ -193,11 +199,14 @@ static int iTCO_wdt_unset_NO_REBOOT_bit(struct iTCO_wdt_private *p)
    >
    > /* Unset the NO_REBOOT bit: this enables reboots */
    > if (p->iTCO_version >= 2) {
    > - val32 = readl(p->gcs_pmc);
    > - val32 &= ~enable_bit;
    > - writel(val32, p->gcs_pmc);
    > -
    > - val32 = readl(p->gcs_pmc);
    > + if (p->update_noreboot_flag)
    > + return p->update_noreboot_flag(0);
    > + else {
    > + val32 = readl(p->gcs_pmc);
    > + val32 &= ~enable_bit;
    > + writel(val32, p->gcs_pmc);
    > + val32 = readl(p->gcs_pmc);
    > + }
    > } else if (p->iTCO_version == 1) {
    > pci_read_config_dword(p->pci_dev, 0xd4, &val32);
    > val32 &= ~enable_bit;
    > @@ -426,13 +435,14 @@ static int iTCO_wdt_probe(struct platform_device *pdev)
    > return -ENODEV;
    >
    > p->iTCO_version = pdata->version;
    > + p->update_noreboot_flag = pdata->update_noreboot_flag;
    > p->pci_dev = to_pci_dev(dev->parent);
    >
    > /*
    > * Get the Memory-Mapped GCS or PMC register, we need it for the
    > * NO_REBOOT flag (TCO v2 and v3).
    > */
    > - if (p->iTCO_version >= 2) {
    > + if (p->iTCO_version >= 2 && !p->update_noreboot_flag) {
    > p->gcs_pmc_res = platform_get_resource(pdev,
    > IORESOURCE_MEM,
    > ICH_RES_MEM_GCS_PMC);
    > diff --git a/include/linux/platform_data/itco_wdt.h b/include/linux/platform_data/itco_wdt.h
    > index f16542c..ea1efb7 100644
    > --- a/include/linux/platform_data/itco_wdt.h
    > +++ b/include/linux/platform_data/itco_wdt.h
    > @@ -14,6 +14,7 @@
    > struct itco_wdt_platform_data {
    > char name[32];
    > unsigned int version;
    > + int (*update_noreboot_flag)(bool status);
    > };
    >
    > #endif /* _ITCO_WDT_H_ */

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