Messages in this thread | | | Subject | Re: [RFC PATCH v2] watchdog: sp805: Add clock-frequency property | From | Guenter Roeck <> | Date | Mon, 9 Jul 2018 06:45:09 -0700 |
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On 07/09/2018 03:19 AM, Srinath Mannam wrote: > When using ACPI node, binding clock devices are > not available as device tree, So clock-frequency > property given in _DSD object of ACPI device is > used to calculate Watchdog rate. > > Signed-off-by: Srinath Mannam <srinath.mannam@broadcom.com> > --- > drivers/watchdog/sp805_wdt.c | 34 ++++++++++++++++++++++++++-------- > 1 file changed, 26 insertions(+), 8 deletions(-) > > diff --git a/drivers/watchdog/sp805_wdt.c b/drivers/watchdog/sp805_wdt.c > index 9849db0..ad5ed64 100644 > --- a/drivers/watchdog/sp805_wdt.c > +++ b/drivers/watchdog/sp805_wdt.c > @@ -11,6 +11,7 @@ > * warranty of any kind, whether express or implied. > */ > > +#include <linux/acpi.h> > #include <linux/device.h> > #include <linux/resource.h> > #include <linux/amba/bus.h> > @@ -22,6 +23,7 @@ > #include <linux/math64.h> > #include <linux/module.h> > #include <linux/moduleparam.h> > +#include <linux/of.h> > #include <linux/pm.h> > #include <linux/slab.h> > #include <linux/spinlock.h> > @@ -65,6 +67,7 @@ struct sp805_wdt { > spinlock_t lock; > void __iomem *base; > struct clk *clk; > + u64 rate; > struct amba_device *adev; > unsigned int load_val; > }; > @@ -80,7 +83,7 @@ static int wdt_setload(struct watchdog_device *wdd, unsigned int timeout) > struct sp805_wdt *wdt = watchdog_get_drvdata(wdd); > u64 load, rate; > > - rate = clk_get_rate(wdt->clk); > + rate = wdt->rate; > > /* > * sp805 runs counter with given value twice, after the end of first > @@ -106,9 +109,7 @@ static int wdt_setload(struct watchdog_device *wdd, unsigned int timeout) > static unsigned int wdt_timeleft(struct watchdog_device *wdd) > { > struct sp805_wdt *wdt = watchdog_get_drvdata(wdd); > - u64 load, rate; > - > - rate = clk_get_rate(wdt->clk); > + u64 load; > > spin_lock(&wdt->lock); > load = readl_relaxed(wdt->base + WDTVALUE); > @@ -118,7 +119,7 @@ static unsigned int wdt_timeleft(struct watchdog_device *wdd) > load += wdt->load_val + 1; > spin_unlock(&wdt->lock); > > - return div_u64(load, rate); > + return div_u64(load, wdt->rate); > } > > static int > @@ -228,10 +229,27 @@ sp805_wdt_probe(struct amba_device *adev, const struct amba_id *id) > if (IS_ERR(wdt->base)) > return PTR_ERR(wdt->base); > > - wdt->clk = devm_clk_get(&adev->dev, NULL); > - if (IS_ERR(wdt->clk)) { > + if (adev->dev.of_node) { > + wdt->clk = devm_clk_get(&adev->dev, NULL); > + if (IS_ERR(wdt->clk)) { > + ret = PTR_ERR(wdt->clk); > + wdt->clk = NULL;
Clearing wdt->clk is useless.
> + } else > + wdt->rate = clk_get_rate(wdt->clk);
The else branch should be in { } as well per coding style.
> + } else if (has_acpi_companion(&adev->dev)) { > + /* > + * When Driver probe with ACPI device, clock devices > + * are not available, so watchdog rate get from > + * clock-frequency property given in _DSD object. > + */ > + device_property_read_u64(&adev->dev, "clock-frequency", > + &wdt->rate);
Continuation line alignment is off.
Still not documented. Maybe that is common for ACPI devices nowadays. If so, I'll need at least a pointer to a document or something declaring that ACPI devices do not use well documented properties, and a confirmation that using such properties is acceptable in the Linux kernel.
> + if (!wdt->rate) > + ret = -ENODEV; > + } > + > + if (ret) { > dev_warn(&adev->dev, "Clock not found\n"); > - ret = PTR_ERR(wdt->clk); > goto err; > }
Please move the error handling to where the error occurs. While doing that, please change the message to dev_err() - this is an error, not a warning - and change the second error message to match the error (it did not find the property).
Also, return directly - the goto just generates another error message which is ridiculous.
Thanks, Guenter
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