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Date: Fri, 31 Jul 2015 11:41:04 +0300
From: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To: Matt Fleming <matt@...eblueprint.co.uk>,
Wim Van Sebroeck <wim@...ana.be>
Cc: linux-kernel@...r.kernel.org, linux-watchdog@...r.kernel.org,
Mika Westerberg <mika.westerberg@...ux.intel.com>,
Jean Delvare <jdelvare@...e.com>,
Wolfram Sang <wsa@...-dreams.de>,
Lee Jones <lee.jones@...aro.org>,
Guenter Roeck <linux@...ck-us.net>,
Matt Fleming <matt.fleming@...el.com>
Subject: Re: [PATCH v3 3/3] iTCO_wdt: Add support for TCO on Intel
Sunrisepoint
On Thu, 2015-07-30 at 22:59 +0100, Matt Fleming wrote:
> From: Matt Fleming <matt.fleming@...el.com>
>
> The revision of the watchdog hardware in Sunrisepoint necessitates a
> new
> "version" inside the TCO watchdog driver because some of the register
> layouts have changed.
>
> Also update the Kconfig entry to select both the LPC and SMBus
> drivers
> since the TCO device is on the SMBus in Sunrisepoint.
Few minor comments below, though I'm okay with current version as well.
>
> Cc: Wim Van Sebroeck <wim@...ana.be>
> Reviewed-by: Guenter Roeck <linux@...ck-us.net>
> Cc: Jean Delvare <jdelvare@...e.com>
> Signed-off-by: Matt Fleming <matt.fleming@...el.com>
> ---
>
> v3:
> - Added Guenter's Review tag
>
> v2:
> - Explicitly list TCO versions and their "no reboot" bits in the
> switch
> statement in no_reboot_bit()
> - Use a switch/case statement when clearing status bits instead of
> convoluted if/else branching
> - Select both of the bus drivers instead of using depends
>
> drivers/watchdog/Kconfig | 3 ++-
> drivers/watchdog/iTCO_wdt.c | 66 ++++++++++++++++++++++++++++-------
> ----------
> 2 files changed, 43 insertions(+), 26 deletions(-)
>
> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
> index 241fafde42cb..55c4b5b0a317 100644
> --- a/drivers/watchdog/Kconfig
> +++ b/drivers/watchdog/Kconfig
> @@ -797,7 +797,8 @@ config ITCO_WDT
> tristate "Intel TCO Timer/Watchdog"
> depends on (X86 || IA64) && PCI
> select WATCHDOG_CORE
> - select LPC_ICH
> + select LPC_ICH if !EXPERT
> + select I2C_I801 if !EXPERT
> ---help---
> Hardware driver for the intel TCO timer based watchdog
> devices.
> These drivers are included in the Intel 82801 I/O
> Controller
> diff --git a/drivers/watchdog/iTCO_wdt.c
> b/drivers/watchdog/iTCO_wdt.c
> index a94401b2deca..7b8949d48029 100644
> --- a/drivers/watchdog/iTCO_wdt.c
> +++ b/drivers/watchdog/iTCO_wdt.c
> @@ -145,58 +145,67 @@ static inline unsigned int ticks_to_seconds(int
> ticks)
> return iTCO_wdt_private.iTCO_version == 3 ? ticks : (ticks *
> 6) / 10;
> }
>
> +static inline u32 no_reboot_bit(void)
> +{
> + u32 enable_bit;
> +
> + switch (iTCO_wdt_private.iTCO_version) {
> + case 3:
> + enable_bit = 0x00000010;
> + break;
> + case 2:
> + enable_bit = 0x00000020;
> + break;
> + case 4:
> + case 1:
> + default:
> + enable_bit = 0x00000002;
> + break;
> + }
> +
> + return enable_bit;
> +}
> +
> static void iTCO_wdt_set_NO_REBOOT_bit(void)
> {
> u32 val32;
>
> /* Set the NO_REBOOT bit: this disables reboots */
> - if (iTCO_wdt_private.iTCO_version == 3) {
> - val32 = readl(iTCO_wdt_private.gcs_pmc);
> - val32 |= 0x00000010;
> - writel(val32, iTCO_wdt_private.gcs_pmc);
> - } else if (iTCO_wdt_private.iTCO_version == 2) {
> + if (iTCO_wdt_private.iTCO_version >= 2) {
> val32 = readl(iTCO_wdt_private.gcs_pmc);
> - val32 |= 0x00000020;
> + val32 |= no_reboot_bit();
> writel(val32, iTCO_wdt_private.gcs_pmc);
> } else if (iTCO_wdt_private.iTCO_version == 1) {
> pci_read_config_dword(iTCO_wdt_private.pdev, 0xd4,
> &val32);
> - val32 |= 0x00000002;
> + val32 |= no_reboot_bit();
> pci_write_config_dword(iTCO_wdt_private.pdev, 0xd4,
> val32);
> }
> }
>
> static int iTCO_wdt_unset_NO_REBOOT_bit(void)
> {
> + u32 enable_bit = no_reboot_bit();
> int ret = 0;
> - u32 val32;
> + u32 val32 = 0;
>
> /* Unset the NO_REBOOT bit: this enables reboots */
> - if (iTCO_wdt_private.iTCO_version == 3) {
> - val32 = readl(iTCO_wdt_private.gcs_pmc);
> - val32 &= 0xffffffef;
> - writel(val32, iTCO_wdt_private.gcs_pmc);
> -
> - val32 = readl(iTCO_wdt_private.gcs_pmc);
> - if (val32 & 0x00000010)
> - ret = -EIO;
> - } else if (iTCO_wdt_private.iTCO_version == 2) {
> + if (iTCO_wdt_private.iTCO_version >= 2) {
> val32 = readl(iTCO_wdt_private.gcs_pmc);
> - val32 &= 0xffffffdf;
> + val32 &= ~enable_bit;
> writel(val32, iTCO_wdt_private.gcs_pmc);
>
> val32 = readl(iTCO_wdt_private.gcs_pmc);
> - if (val32 & 0x00000020)
> - ret = -EIO;
> } else if (iTCO_wdt_private.iTCO_version == 1) {
> pci_read_config_dword(iTCO_wdt_private.pdev, 0xd4,
> &val32);
> - val32 &= 0xfffffffd;
> + val32 &= ~enable_bit;
> pci_write_config_dword(iTCO_wdt_private.pdev, 0xd4,
> val32);
>
> pci_read_config_dword(iTCO_wdt_private.pdev, 0xd4,
> &val32);
> - if (val32 & 0x00000002)
> - ret = -EIO;
> }
>
> + if (val32 & enable_bit)
> + ret = -EIO;
> +
> return ret; /* returns: 0 = OK, -EIO = Error */
What about removing ret at all?
if (val32 & enable_bit)
return -EIO;
return 0;
> }
>
> @@ -503,12 +512,19 @@ static int iTCO_wdt_probe(struct
> platform_device *dev)
> pdata->name, pdata->version, (u64)TCOBASE);
>
> /* Clear out the (probably old) status */
> - if (iTCO_wdt_private.iTCO_version == 3) {
> + switch (iTCO_wdt_private.iTCO_version) {
> + case 4:
> + outw(0x0008, TCO1_STS); /* Clear the Time
> Out Status bit */
> + outw(0x0002, TCO2_STS); /* Clear
> SECOND_TO_STS bit */
> + break;
> + case 3:
> outl(0x20008, TCO1_STS);
> - } else {
> + break;
> + default:
Same idea here: put cases explicitly for all existing versions?
case 2:
case 1:
default:
> outw(0x0008, TCO1_STS); /* Clear the Time
> Out Status bit */
> outw(0x0002, TCO2_STS); /* Clear
> SECOND_TO_STS bit */
> outw(0x0004, TCO2_STS); /* Clear BOOT_STS
> bit */
> + break;
> }
>
> iTCO_wdt_watchdog_dev.bootstatus = 0;
--
Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
Intel Finland Oy
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