Re: [PATCH 06/22] watchdog: remove the shwdt driver

On 1/12/23 22:23, Christoph Hellwig wrote:

Now that arch/sh is removed this driver is dead code.

Signed-off-by: Christoph Hellwig hch@lst.de

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

---

.../watchdog/watchdog-parameters.rst | 12 - drivers/watchdog/Kconfig | 20 - drivers/watchdog/Makefile | 3 - drivers/watchdog/shwdt.c | 344 ------------------ 4 files changed, 379 deletions(-) delete mode 100644 drivers/watchdog/shwdt.c

diff --git a/Documentation/watchdog/watchdog-parameters.rst b/Documentation/watchdog/watchdog-parameters.rst index 29153eed668900..553ac2f8ae23f7 100644 --- a/Documentation/watchdog/watchdog-parameters.rst +++ b/Documentation/watchdog/watchdog-parameters.rst @@ -579,18 +579,6 @@ scx200_wdt:

---

-shwdt:

• clock_division_ratio:
• Clock division ratio. Valid ranges are from 0x5 (1.31ms)
• to 0x7 (5.25ms). (default=7)
• heartbeat:
• Watchdog heartbeat in seconds. (1 <= heartbeat <= 3600, default=30
• nowayout:
• Watchdog cannot be stopped once started
• (default=kernel config parameter)

---

• smsc37b787_wdt: timeout: range is 1-255 units, default is 60

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index 0bc40b763b0652..7db0a5e636cf65 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -2015,26 +2015,6 @@ config DIAG288_WATCHDOG To compile this driver as a module, choose M here. The module will be called diag288_wdt.

-# SUPERH (sh + sh64) Architecture

-config SH_WDT

• tristate "SuperH Watchdog"

• depends on SUPERH && (CPU_SH3 || CPU_SH4 || COMPILE_TEST)

• select WATCHDOG_CORE

• help

•  This driver adds watchdog support for the integrated watchdog in the
  

•  SuperH processors. If you have one of these processors and wish
  

•  to have watchdog support enabled, say Y, otherwise say N.
  

•  As a side note, saying Y here will automatically boost HZ to 1000
  

•  so that the timer has a chance to clear the overflow counter. On
  

•  slower systems (such as the SH-2 and SH-3) this will likely yield
  

•  some performance issues. As such, the WDT should be avoided here
  

•  unless it is absolutely necessary.
  

•  To compile this driver as a module, choose M here: the
  

•  module will be called shwdt.
  

• # SPARC Architecture

  # SPARC64 Architecture

diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index 9cbf6580f16c9f..a852ab4d7176ac 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -195,9 +195,6 @@ obj-$(CONFIG_WATCHDOG_RTAS) += wdrtas.o # S390 Architecture obj-$(CONFIG_DIAG288_WATCHDOG) += diag288_wdt.o

-# SUPERH (sh + sh64) Architecture -obj-$(CONFIG_SH_WDT) += shwdt.o

• # SPARC Architecture

  # SPARC64 Architecture

diff --git a/drivers/watchdog/shwdt.c b/drivers/watchdog/shwdt.c deleted file mode 100644 index f55533e0e0454e..00000000000000 --- a/drivers/watchdog/shwdt.c +++ /dev/null @@ -1,344 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-or-later -/*

• • drivers/watchdog/shwdt.c
• • Watchdog driver for integrated watchdog in the SuperH processors.
• • Copyright (C) 2001 - 2012 Paul Mundt lethal@linux-sh.org
• • 14-Dec-2001 Matt Domsch Matt_Domsch@dell.com

• • Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT
    

• • 19-Apr-2002 Rob Radez rob@osinvestor.com

• • Added expect close support, made emulated timeout runtime changeable
    

• • general cleanups, add some ioctls
    

• */

-#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

-#include <linux/module.h> -#include <linux/moduleparam.h> -#include <linux/platform_device.h> -#include <linux/init.h> -#include <linux/types.h> -#include <linux/spinlock.h> -#include <linux/watchdog.h> -#include <linux/pm_runtime.h> -#include <linux/fs.h> -#include <linux/mm.h> -#include <linux/slab.h> -#include <linux/io.h> -#include <linux/clk.h> -#include <linux/err.h> -#include <asm/watchdog.h>

-#define DRV_NAME "sh-wdt"

-/*

• • Default clock division ratio is 5.25 msecs. For an additional table of
• • values, consult the asm-sh/watchdog.h. Overload this at module load
• • time.
• • In order for this to work reliably we need to have HZ set to 1000 or
• • something quite higher than 100 (or we need a proper high-res timer
• • implementation that will deal with this properly), otherwise the 10ms
• • resolution of a jiffy is enough to trigger the overflow. For things like
• • the SH-4 and SH-5, this isn't necessarily that big of a problem, though
• • for the SH-2 and SH-3, this isn't recommended unless the WDT is absolutely
• • necssary.
• • As a result of this timing problem, the only modes that are particularly
• • feasible are the 4096 and the 2048 divisors, which yield 5.25 and 2.62ms
• • overflow periods respectively.
• • Also, since we can't really expect userspace to be responsive enough
• • before the overflow happens, we maintain two separate timers .. One in
• • the kernel for clearing out WOVF every 2ms or so (again, this depends on
• • HZ == 1000), and another for monitoring userspace writes to the WDT device.
• • As such, we currently use a configurable heartbeat interval which defaults
• • to 30s. In this case, the userspace daemon is only responsible for periodic
• • writes to the device before the next heartbeat is scheduled. If the daemon
• • misses its deadline, the kernel timer will allow the WDT to overflow.
• */

-static int clock_division_ratio = WTCSR_CKS_4096; -#define next_ping_period(cks) (jiffies + msecs_to_jiffies(cks - 4))

-#define WATCHDOG_HEARTBEAT 30 /* 30 sec default heartbeat */ -static int heartbeat = WATCHDOG_HEARTBEAT; /* in seconds */ -static bool nowayout = WATCHDOG_NOWAYOUT; -static unsigned long next_heartbeat;

-struct sh_wdt {

• void __iomem *base;
• struct device *dev;
• struct clk *clk;
• spinlock_t lock;
• struct timer_list timer;

-};

-static int sh_wdt_start(struct watchdog_device *wdt_dev) -{

• struct sh_wdt *wdt = watchdog_get_drvdata(wdt_dev);
• unsigned long flags;
• u8 csr;
• pm_runtime_get_sync(wdt->dev);
• clk_enable(wdt->clk);
• spin_lock_irqsave(&wdt->lock, flags);
• next_heartbeat = jiffies + (heartbeat * HZ);
• mod_timer(&wdt->timer, next_ping_period(clock_division_ratio));
• csr = sh_wdt_read_csr();
• csr |= WTCSR_WT | clock_division_ratio;
• sh_wdt_write_csr(csr);
• sh_wdt_write_cnt(0);
• /*

• * These processors have a bit of an inconsistent initialization
  

• * process.. starting with SH-3, RSTS was moved to WTCSR, and the
  

• * RSTCSR register was removed.
  

• *
  

• * On the SH-2 however, in addition with bits being in different
  

• * locations, we must deal with RSTCSR outright..
  

• */
  

• csr = sh_wdt_read_csr();
• csr |= WTCSR_TME;
• csr &= ~WTCSR_RSTS;
• sh_wdt_write_csr(csr);

-#ifdef CONFIG_CPU_SH2

• csr = sh_wdt_read_rstcsr();
• csr &= ~RSTCSR_RSTS;
• sh_wdt_write_rstcsr(csr);

-#endif

• spin_unlock_irqrestore(&wdt->lock, flags);
• return 0;

-}

-static int sh_wdt_stop(struct watchdog_device *wdt_dev) -{

• struct sh_wdt *wdt = watchdog_get_drvdata(wdt_dev);
• unsigned long flags;
• u8 csr;
• spin_lock_irqsave(&wdt->lock, flags);
• del_timer(&wdt->timer);
• csr = sh_wdt_read_csr();
• csr &= ~WTCSR_TME;
• sh_wdt_write_csr(csr);
• spin_unlock_irqrestore(&wdt->lock, flags);
• clk_disable(wdt->clk);
• pm_runtime_put_sync(wdt->dev);
• return 0;

-}

-static int sh_wdt_keepalive(struct watchdog_device *wdt_dev) -{

• struct sh_wdt *wdt = watchdog_get_drvdata(wdt_dev);
• unsigned long flags;
• spin_lock_irqsave(&wdt->lock, flags);
• next_heartbeat = jiffies + (heartbeat * HZ);
• spin_unlock_irqrestore(&wdt->lock, flags);
• return 0;

-}

-static int sh_wdt_set_heartbeat(struct watchdog_device *wdt_dev, unsigned t) -{

• struct sh_wdt *wdt = watchdog_get_drvdata(wdt_dev);
• unsigned long flags;
• if (unlikely(t < 1 || t > 3600)) /* arbitrary upper limit */

• return -EINVAL;
  

• spin_lock_irqsave(&wdt->lock, flags);
• heartbeat = t;
• wdt_dev->timeout = t;
• spin_unlock_irqrestore(&wdt->lock, flags);
• return 0;

-}

-static void sh_wdt_ping(struct timer_list *t) -{

• struct sh_wdt *wdt = from_timer(wdt, t, timer);
• unsigned long flags;
• spin_lock_irqsave(&wdt->lock, flags);
• if (time_before(jiffies, next_heartbeat)) {

• u8 csr;
  

• csr = sh_wdt_read_csr();
  

• csr &= ~WTCSR_IOVF;
  

• sh_wdt_write_csr(csr);
  

• sh_wdt_write_cnt(0);
  

• mod_timer(&wdt->timer, next_ping_period(clock_division_ratio));
  

• } else

• dev_warn(wdt->dev, "Heartbeat lost! Will not ping "
  

•          "the watchdog\n");
  

• spin_unlock_irqrestore(&wdt->lock, flags);

-}

-static const struct watchdog_info sh_wdt_info = {

• .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT |

• 		  WDIOF_MAGICCLOSE,
  

• .firmware_version = 1,
• .identity = "SH WDT",

-};

-static const struct watchdog_ops sh_wdt_ops = {

• .owner = THIS_MODULE,
• .start = sh_wdt_start,
• .stop = sh_wdt_stop,
• .ping = sh_wdt_keepalive,
• .set_timeout = sh_wdt_set_heartbeat,

-};

-static struct watchdog_device sh_wdt_dev = {

• .info = &sh_wdt_info,
• .ops = &sh_wdt_ops,

-};

-static int sh_wdt_probe(struct platform_device *pdev) -{

• struct sh_wdt *wdt;
• int rc;
• /*

• * As this driver only covers the global watchdog case, reject
  

• * any attempts to register per-CPU watchdogs.
  

• */
  

• if (pdev->id != -1)

• return -EINVAL;
  

• wdt = devm_kzalloc(&pdev->dev, sizeof(struct sh_wdt), GFP_KERNEL);
• if (unlikely(!wdt))

• return -ENOMEM;
  

• wdt->dev = &pdev->dev;
• wdt->clk = devm_clk_get(&pdev->dev, NULL);
• if (IS_ERR(wdt->clk)) {

• /*
  

•  * Clock framework support is optional, continue on
  

•  * anyways if we don't find a matching clock.
  

•  */
  

• wdt->clk = NULL;
  

• }
• wdt->base = devm_platform_ioremap_resource(pdev, 0);
• if (IS_ERR(wdt->base))

• return PTR_ERR(wdt->base);
  

• watchdog_set_nowayout(&sh_wdt_dev, nowayout);
• watchdog_set_drvdata(&sh_wdt_dev, wdt);
• sh_wdt_dev.parent = &pdev->dev;
• spin_lock_init(&wdt->lock);
• rc = sh_wdt_set_heartbeat(&sh_wdt_dev, heartbeat);
• if (unlikely(rc)) {

• /* Default timeout if invalid */
  

• sh_wdt_set_heartbeat(&sh_wdt_dev, WATCHDOG_HEARTBEAT);
  

• dev_warn(&pdev->dev,
  

• 	 "heartbeat value must be 1<=x<=3600, using %d\n",
  

• 	 sh_wdt_dev.timeout);
  

• }
• dev_info(&pdev->dev, "configured with heartbeat=%d sec (nowayout=%d)\n",

•  sh_wdt_dev.timeout, nowayout);
  

• rc = watchdog_register_device(&sh_wdt_dev);
• if (unlikely(rc)) {

• dev_err(&pdev->dev, "Can't register watchdog (err=%d)\n", rc);
  

• return rc;
  

• }
• timer_setup(&wdt->timer, sh_wdt_ping, 0);
• wdt->timer.expires = next_ping_period(clock_division_ratio);
• dev_info(&pdev->dev, "initialized.\n");
• pm_runtime_enable(&pdev->dev);
• return 0;

-}

-static int sh_wdt_remove(struct platform_device *pdev) -{

• watchdog_unregister_device(&sh_wdt_dev);
• pm_runtime_disable(&pdev->dev);
• return 0;

-}

-static void sh_wdt_shutdown(struct platform_device *pdev) -{

• sh_wdt_stop(&sh_wdt_dev);

-}

-static struct platform_driver sh_wdt_driver = {

• .driver = {

• .name	= DRV_NAME,
  

• },
• .probe = sh_wdt_probe,
• .remove = sh_wdt_remove,
• .shutdown = sh_wdt_shutdown,

-};

-static int __init sh_wdt_init(void) -{

• if (unlikely(clock_division_ratio < 0x5 ||

•      clock_division_ratio > 0x7)) {
  

• clock_division_ratio = WTCSR_CKS_4096;
  

• pr_info("divisor must be 0x5<=x<=0x7, using %d\n",
  

• 	clock_division_ratio);
  

• }
• return platform_driver_register(&sh_wdt_driver);

-}

-static void __exit sh_wdt_exit(void) -{

• platform_driver_unregister(&sh_wdt_driver);

-} -module_init(sh_wdt_init); -module_exit(sh_wdt_exit);

-MODULE_AUTHOR("Paul Mundt lethal@linux-sh.org"); -MODULE_DESCRIPTION("SuperH watchdog driver"); -MODULE_LICENSE("GPL"); -MODULE_ALIAS("platform:" DRV_NAME);

-module_param(clock_division_ratio, int, 0); -MODULE_PARM_DESC(clock_division_ratio,

• "Clock division ratio. Valid ranges are from 0x5 (1.31ms) "
• "to 0x7 (5.25ms). (default=" __MODULE_STRING(WTCSR_CKS_4096) ")");

-module_param(heartbeat, int, 0); -MODULE_PARM_DESC(heartbeat,

• "Watchdog heartbeat in seconds. (1 <= heartbeat <= 3600, default="

• 		__MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
  

-module_param(nowayout, bool, 0); -MODULE_PARM_DESC(nowayout,

• "Watchdog cannot be stopped once started (default="

• 		__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");