[v2,1/4] watchdog: cadence_wdt: Move clock detection eariler in probe
diff mbox series

Message ID 20190705114522.42565-2-tomas.melin@vaisala.com
State Changes Requested
Headers show
Series
  • watchdog: cadence_wdt: Support all available prescaler values
Related show

Commit Message

Melin Tomas July 5, 2019, 11:46 a.m. UTC
Timeout calculation needs clock frequency, so init clock and calculate
prescaler value eariler in the probe.

Preparational step for calculating maximum and minimum timeout values
for driver.

Signed-off-by: Tomas Melin <tomas.melin@vaisala.com>
---
 drivers/watchdog/cadence_wdt.c | 32 ++++++++++++++++----------------
 1 file changed, 16 insertions(+), 16 deletions(-)

Comments

Guenter Roeck July 8, 2019, 6:03 p.m. UTC | #1
On Fri, Jul 05, 2019 at 11:46:02AM +0000, Melin Tomas wrote:
> Timeout calculation needs clock frequency, so init clock and calculate
> prescaler value eariler in the probe.
> 
earlier; also in subject line

> Preparational step for calculating maximum and minimum timeout values
> for driver.
> 
> Signed-off-by: Tomas Melin <tomas.melin@vaisala.com>
> ---
>  drivers/watchdog/cadence_wdt.c | 32 ++++++++++++++++----------------
>  1 file changed, 16 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/watchdog/cadence_wdt.c b/drivers/watchdog/cadence_wdt.c
> index c3924356d173..415bd6dd1edb 100644
> --- a/drivers/watchdog/cadence_wdt.c
> +++ b/drivers/watchdog/cadence_wdt.c
> @@ -295,6 +295,22 @@ static int cdns_wdt_probe(struct platform_device *pdev)
>  	if (!wdt)
>  		return -ENOMEM;
>  
> +	wdt->clk = devm_clk_get(&pdev->dev, NULL);
> +	if (IS_ERR(wdt->clk)) {
> +		dev_err(&pdev->dev, "input clock not found\n");
> +		ret = PTR_ERR(wdt->clk);
> +		return ret;

		return PTR_ERR(wdt->clk);

[ ok, that is from the old code ... ]

> +	}
> +
> +	clock_f = clk_get_rate(wdt->clk);
> +	if (clock_f <= CDNS_WDT_CLK_75MHZ) {
> +		wdt->prescaler = CDNS_WDT_PRESCALE_512;
> +		wdt->ctrl_clksel = CDNS_WDT_PRESCALE_SELECT_512;
> +	} else {
> +		wdt->prescaler = CDNS_WDT_PRESCALE_4096;
> +		wdt->ctrl_clksel = CDNS_WDT_PRESCALE_SELECT_4096;
> +	}
> +
>  	cdns_wdt_device = &wdt->cdns_wdt_device;
>  	cdns_wdt_device->info = &cdns_wdt_info;
>  	cdns_wdt_device->ops = &cdns_wdt_ops;
> @@ -334,28 +350,12 @@ static int cdns_wdt_probe(struct platform_device *pdev)
>  	watchdog_stop_on_reboot(cdns_wdt_device);
>  	watchdog_set_drvdata(cdns_wdt_device, wdt);
>  
> -	wdt->clk = devm_clk_get(&pdev->dev, NULL);
> -	if (IS_ERR(wdt->clk)) {
> -		dev_err(&pdev->dev, "input clock not found\n");
> -		ret = PTR_ERR(wdt->clk);
> -		return ret;
> -	}
> -
>  	ret = clk_prepare_enable(wdt->clk);
>  	if (ret) {
>  		dev_err(&pdev->dev, "unable to enable clock\n");
>  		return ret;
>  	}
>  
The substantial difference here is that clk_prepare_enable() was called
before the actual clock rate was retrieved. I don't know if that makes
a substantial difference, but on the other side I don't see why the above
code isn't moved as well. What I _do_ see, however, is that this patch
isn't based on the latest mainline kenrel, since mainline has a call to
devm_add_action_or_reset() after clk_prepare_enable(). Please rebase.

> -	clock_f = clk_get_rate(wdt->clk);
> -	if (clock_f <= CDNS_WDT_CLK_75MHZ) {
> -		wdt->prescaler = CDNS_WDT_PRESCALE_512;
> -		wdt->ctrl_clksel = CDNS_WDT_PRESCALE_SELECT_512;
> -	} else {
> -		wdt->prescaler = CDNS_WDT_PRESCALE_4096;
> -		wdt->ctrl_clksel = CDNS_WDT_PRESCALE_SELECT_4096;
> -	}
> -
>  	spin_lock_init(&wdt->io_lock);
>  
>  	ret = watchdog_register_device(cdns_wdt_device);

Patch
diff mbox series

diff --git a/drivers/watchdog/cadence_wdt.c b/drivers/watchdog/cadence_wdt.c
index c3924356d173..415bd6dd1edb 100644
--- a/drivers/watchdog/cadence_wdt.c
+++ b/drivers/watchdog/cadence_wdt.c
@@ -295,6 +295,22 @@  static int cdns_wdt_probe(struct platform_device *pdev)
 	if (!wdt)
 		return -ENOMEM;
 
+	wdt->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(wdt->clk)) {
+		dev_err(&pdev->dev, "input clock not found\n");
+		ret = PTR_ERR(wdt->clk);
+		return ret;
+	}
+
+	clock_f = clk_get_rate(wdt->clk);
+	if (clock_f <= CDNS_WDT_CLK_75MHZ) {
+		wdt->prescaler = CDNS_WDT_PRESCALE_512;
+		wdt->ctrl_clksel = CDNS_WDT_PRESCALE_SELECT_512;
+	} else {
+		wdt->prescaler = CDNS_WDT_PRESCALE_4096;
+		wdt->ctrl_clksel = CDNS_WDT_PRESCALE_SELECT_4096;
+	}
+
 	cdns_wdt_device = &wdt->cdns_wdt_device;
 	cdns_wdt_device->info = &cdns_wdt_info;
 	cdns_wdt_device->ops = &cdns_wdt_ops;
@@ -334,28 +350,12 @@  static int cdns_wdt_probe(struct platform_device *pdev)
 	watchdog_stop_on_reboot(cdns_wdt_device);
 	watchdog_set_drvdata(cdns_wdt_device, wdt);
 
-	wdt->clk = devm_clk_get(&pdev->dev, NULL);
-	if (IS_ERR(wdt->clk)) {
-		dev_err(&pdev->dev, "input clock not found\n");
-		ret = PTR_ERR(wdt->clk);
-		return ret;
-	}
-
 	ret = clk_prepare_enable(wdt->clk);
 	if (ret) {
 		dev_err(&pdev->dev, "unable to enable clock\n");
 		return ret;
 	}
 
-	clock_f = clk_get_rate(wdt->clk);
-	if (clock_f <= CDNS_WDT_CLK_75MHZ) {
-		wdt->prescaler = CDNS_WDT_PRESCALE_512;
-		wdt->ctrl_clksel = CDNS_WDT_PRESCALE_SELECT_512;
-	} else {
-		wdt->prescaler = CDNS_WDT_PRESCALE_4096;
-		wdt->ctrl_clksel = CDNS_WDT_PRESCALE_SELECT_4096;
-	}
-
 	spin_lock_init(&wdt->io_lock);
 
 	ret = watchdog_register_device(cdns_wdt_device);