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.
> 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
> > 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));
> > + return PTR_ERR(wdt->gpio_wdi);
> > + }
> > +
> > + if (!IS_ERR(wdt->gpio_wdi))
> > + wdt->ping = max63xx_gpio_ping;
> > + else
> > + wdt->gpio_wdi = NULL;
> > +
> > err = max63xx_mmap_init(pdev, wdt);
> > if (err)
> > return err;
>
