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 ? 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;
