[PATCH (v3) 6/11] watchdog: bcm63xx_wdt: Obtain watchdog clock HZ from "periph" clk

Simon Arlott
2015-11-25T22:47:59Z

Instead of using a fixed clock HZ in the driver, obtain it from the
"periph" clk that the watchdog timer uses.

Signed-off-by: Simon Arlott <simon-A6De1vDTPLDsq35pWSNszA@public.gmane.org>
---
Patch 7 split into two patches.

On 24/11/15 22:42, Florian Fainelli wrote:
> On 24/11/15 14:12, Simon Arlott wrote:
>> Instead of using a fixed clock HZ in the driver, obtain it from the
>> "periph" clk that the watchdog timer uses.
>>
>> Signed-off-by: Simon Arlott <simon-A6De1vDTPLDsq35pWSNszA@public.gmane.org>
>
> Reviewed-by: Florian Fainelli <f.fainelli-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
>

Changed because of the reordering of timer/watchdog register calls.

drivers/watchdog/bcm63xx_wdt.c | 36 +++++++++++++++++++++++++++++++-----
1 file changed, 31 insertions(+), 5 deletions(-)

diff --git a/drivers/watchdog/bcm63xx_wdt.c b/drivers/watchdog/bcm63xx_wdt.c
index 2257924..0a19731 100644
--- a/drivers/watchdog/bcm63xx_wdt.c
+++ b/drivers/watchdog/bcm63xx_wdt.c
@@ -13,6 +13,7 @@

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

+#include <linux/clk.h>
#include <linux/errno.h>
#include <linux/io.h>
#include <linux/kernel.h>
@@ -32,12 +33,14 @@

#define PFX KBUILD_MODNAME

-#define WDT_HZ 50000000 /* Fclk */
+#define WDT_CLK_NAME "periph"

struct bcm63xx_wdt_hw {
struct watchdog_device wdd;
raw_spinlock_t lock;
void __iomem *regs;
+ struct clk *clk;
+ unsigned long clock_hz;
bool running;
};

@@ -54,7 +57,7 @@ static int bcm63xx_wdt_start(struct watchdog_device *wdd)
unsigned long flags;

raw_spin_lock_irqsave(&hw->lock, flags);
- bcm_writel(wdd->timeout * WDT_HZ, hw->regs + WDT_DEFVAL_REG);
+ bcm_writel(wdd->timeout * hw->clock_hz, hw->regs + WDT_DEFVAL_REG);
bcm_writel(WDT_START_1, hw->regs + WDT_CTL_REG);
bcm_writel(WDT_START_2, hw->regs + WDT_CTL_REG);
hw->running = true;
@@ -118,7 +121,7 @@ static void bcm63xx_wdt_isr(void *data)
die(PFX ": watchdog timer expired\n", get_irq_regs());
}

- ms = timeleft / (WDT_HZ / 1000);
+ ms = timeleft / (hw->clock_hz / 1000);
dev_alert(hw->wdd.dev,
"warning timer fired, reboot in %ums\n", ms);
}
@@ -162,6 +165,25 @@ static int bcm63xx_wdt_probe(struct platform_device *pdev)
return -ENXIO;
}

+ hw->clk = devm_clk_get(&pdev->dev, WDT_CLK_NAME);
+ if (IS_ERR(hw->clk)) {
+ if (PTR_ERR(hw->clk) != -EPROBE_DEFER)
+ dev_err(&pdev->dev, "unable to request clock\n");
+ return PTR_ERR(hw->clk);
+ }
+
+ hw->clock_hz = clk_get_rate(hw->clk);
+ if (!hw->clock_hz) {
+ dev_err(&pdev->dev, "unable to fetch clock rate\n");
+ return -EINVAL;
+ }
+
+ ret = clk_prepare_enable(hw->clk);
+ if (ret) {
+ dev_err(&pdev->dev, "unable to enable clock\n");
+ return ret;
+ }
+
raw_spin_lock_init(&hw->lock);
hw->running = false;

@@ -169,7 +191,7 @@ static int bcm63xx_wdt_probe(struct platform_device *pdev)
wdd->ops = &bcm63xx_wdt_ops;
wdd->info = &bcm63xx_wdt_info;
wdd->min_timeout = 1;
- wdd->max_timeout = 0xffffffff / WDT_HZ;
+ wdd->max_timeout = 0xffffffff / hw->clock_hz;
wdd->timeout = min(30U, wdd->max_timeout);

platform_set_drvdata(pdev, hw);
@@ -180,7 +202,7 @@ static int bcm63xx_wdt_probe(struct platform_device *pdev)
ret = watchdog_register_device(wdd);
if (ret < 0) {
dev_err(&pdev->dev, "failed to register watchdog device\n");
- return ret;
+ goto disable_clk;
}

ret = bcm63xx_timer_register(TIMER_WDT_ID, bcm63xx_wdt_isr, hw);
@@ -198,6 +220,9 @@ static int bcm63xx_wdt_probe(struct platform_device *pdev)

unregister_watchdog:
watchdog_unregister_device(wdd);
+
+disable_clk:
+ clk_disable_unprepare(hw->clk);
return ret;
}

@@ -207,6 +232,7 @@ static int bcm63xx_wdt_remove(struct platform_device *pdev)

bcm63xx_timer_unregister(TIMER_WDT_ID);
watchdog_unregister_device(&hw->wdd);
+ clk_disable_unprepare(hw->clk);
return 0;
}

--
2.1.4