On Thursday 28 April 2022 08:29:52 Guenter Roeck wrote:
> On 4/28/22 07:32, Pali Rohár wrote:
> > On Thursday 28 April 2022 06:10:56 Guenter Roeck wrote:
> > > On 4/28/22 02:16, Pali Rohár wrote:
> > > > On some boards is WDI logic of max6370 chip connected via GPIO. So extend
> > > > max63xx_wdt driver and DTS schema to allow specifying WDI logic via GPIO.
> > > >
> > > > Signed-off-by: Pali Rohár <pali@xxxxxxxxxx>
> > >
> > > How is that different to just using the gpio watchdog driver ?
> >
> > GPIO watchdog driver does not support max6370 memory mapped
> > configuration.
> >
> > With this change, max6370 can use memory mapped space for watchdog
> > configuration and GPIO WDI for pinging.
> >
>
> Ok, that makes sense. Comments below.
>
> Thanks,
> Guenter
>
> > > Guenter
> > >
> > > > ---
> > > > .../bindings/watchdog/maxim,max63xx.yaml | 4 +++
> > > > drivers/watchdog/max63xx_wdt.c | 28 +++++++++++++++++++
> > > > 2 files changed, 32 insertions(+)
> > > >
> > > > diff --git a/Documentation/devicetree/bindings/watchdog/maxim,max63xx.yaml b/Documentation/devicetree/bindings/watchdog/maxim,max63xx.yaml
> > > > index ab9641e845db..a97aa0135ef9 100644
> > > > --- a/Documentation/devicetree/bindings/watchdog/maxim,max63xx.yaml
> > > > +++ b/Documentation/devicetree/bindings/watchdog/maxim,max63xx.yaml
> > > > @@ -27,6 +27,10 @@ properties:
> > > > description: This is a 1-byte memory-mapped address
> > > > maxItems: 1
> > > > + gpios:
> > > > + description: Optional GPIO used for controlling WDI when WDI bit is not mapped to memory
> > > > + maxItems: 1
> > > > +
> > > > required:
> > > > - compatible
> > > > - reg
>
> Devicetree patches needs to be separate.
Ok.
> > > > diff --git a/drivers/watchdog/max63xx_wdt.c b/drivers/watchdog/max63xx_wdt.c
> > > > index 9e1541cfae0d..eaf00c3f06a5 100644
> > > > --- a/drivers/watchdog/max63xx_wdt.c
> > > > +++ b/drivers/watchdog/max63xx_wdt.c
> > > > @@ -27,6 +27,7 @@
> > > > #include <linux/io.h>
> > > > #include <linux/slab.h>
> > > > #include <linux/property.h>
> > > > +#include <linux/gpio/consumer.h>
> > > > #define DEFAULT_HEARTBEAT 60
> > > > #define MAX_HEARTBEAT 60
> > > > @@ -53,6 +54,9 @@ struct max63xx_wdt {
> > > > void __iomem *base;
> > > > spinlock_t lock;
> > > > + /* GPIOs */
> > > > + struct gpio_desc *gpio_wdi;
> > > > +
> > > > /* WDI and WSET bits write access routines */
> > > > void (*ping)(struct max63xx_wdt *wdt);
> > > > void (*set)(struct max63xx_wdt *wdt, u8 set);
> > > > @@ -158,6 +162,17 @@ static const struct watchdog_info max63xx_wdt_info = {
> > > > .identity = "max63xx Watchdog",
> > > > };
> > > > +static void max63xx_gpio_ping(struct max63xx_wdt *wdt)
> > > > +{
> > > > + spin_lock(&wdt->lock);
> > > > +
> > > > + gpiod_set_value_cansleep(wdt->gpio_wdi, 1);
> > > > + udelay(1);
> > > > + gpiod_set_value_cansleep(wdt->gpio_wdi, 0);
> > > > +
> > > > + spin_unlock(&wdt->lock);
> > > > +}
> > > > +
> > > > static void max63xx_mmap_ping(struct max63xx_wdt *wdt)
> > > > {
> > > > u8 val;
> > > > @@ -225,6 +240,19 @@ static int max63xx_wdt_probe(struct platform_device *pdev)
> > > > return -EINVAL;
> > > > }
> > > > + wdt->gpio_wdi = devm_gpiod_get(dev, NULL, GPIOD_FLAGS_BIT_DIR_OUT);
> > > > + if (IS_ERR(wdt->gpio_wdi) && PTR_ERR(wdt->gpio_wdi) != -ENOENT) {
> > > > + if (PTR_ERR(wdt->gpio_wdi) != -EPROBE_DEFER)
> > > > + dev_err(dev, "unable to request gpio: %ld\n",
> > > > + PTR_ERR(wdt->gpio_wdi));
>
> Please use dev_err_probe().
Ok.
> > > > + return PTR_ERR(wdt->gpio_wdi);
> > > > + }
> > > > +
> > > > + if (!IS_ERR(wdt->gpio_wdi))
> > > > + wdt->ping = max63xx_gpio_ping;
> > > > + else
> > > > + wdt->gpio_wdi = NULL;
>
> Why set gpio_wdi to NULL? It isn't used if the ping function is not set.
I thought that it would be more safer to have NULL value stored in
pointer variable as opposite of some non-NULL value used for the error
reporting. But I can remove this part of the code.
> > > > +
> > > > err = max63xx_mmap_init(pdev, wdt);
>
> Doesn't this override the gpio ping function set above ?
Yes, it does. I forgot to amend local change to this patch. wdt->ping
has to be changed to gpio_ping _after_ max63xx_mmap_init call.
I will fix all those issues in v2.
> > > > if (err)
> > > > return err;
> > >
>
