| Message ID | 20220429131349.21229-2-pali@kernel.org |
|---|---|
| State | New |
| Headers | show |
| Series | [v2,1/2] dt-bindings: watchdog: max63xx: Add GPIO binding | expand |
On 5/2/22 20:57, Tzung-Bi Shih wrote: > On Fri, Apr 29, 2022 at 03:13:49PM +0200, Pali Rohár wrote: >> @@ -27,6 +27,7 @@ >> #include <linux/io.h> >> #include <linux/slab.h> >> #include <linux/property.h> >> +#include <linux/gpio/consumer.h> > > It would be better to keep them alphabetically. Anyway, they aren't sorted > originally... > >> +static void max63xx_gpio_ping(struct max63xx_wdt *wdt) >> +{ >> + spin_lock(&wdt->lock); > > Does it really need to acquire the lock? It looks like the lock is to prevent > concurrent accesses to the mmap in max63xx_mmap_ping() and max63xx_mmap_set(). > Actually, that doesn't work at all. spin_lock() directly contradicts with gpiod_set_value_cansleep(). >> + gpiod_set_value_cansleep(wdt->gpio_wdi, 1); >> + udelay(1); > > Doesn't it need to include <linux/delay.h> for udelay()? > >> @@ -225,10 +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) > > Use devm_gpiod_get_optional() to make the intent clear. Also, it gets rid of > the check for -ENOENT. > >> + return dev_err_probe(dev, PTR_ERR(wdt->gpio_wdi), >> + "unable to request gpio: %ld\n", >> + PTR_ERR(wdt->gpio_wdi)); > > It doesn't need to again print for PTR_ERR(wdt->gpio_wdi). dev_err_probe() > prints the error. > >> err = max63xx_mmap_init(pdev, wdt); >> if (err) >> return err; >> >> + if (!IS_ERR(wdt->gpio_wdi)) >> + wdt->ping = max63xx_gpio_ping; > > Thus, the max63xx_gpio_ping() overrides max63xx_mmap_ping() if the GPIO was > provided? It would be better to mention the behavior in the commit message. > > Also, could both the assignments of `wdt->gpio_wdi` and `wdt->ping` happen > after max63xx_mmap_init()?
On Monday 02 May 2022 21:37:16 Guenter Roeck wrote: > On 5/2/22 20:57, Tzung-Bi Shih wrote: > > On Fri, Apr 29, 2022 at 03:13:49PM +0200, Pali Rohár wrote: > > > @@ -27,6 +27,7 @@ > > > #include <linux/io.h> > > > #include <linux/slab.h> > > > #include <linux/property.h> > > > +#include <linux/gpio/consumer.h> > > > > It would be better to keep them alphabetically. Anyway, they aren't sorted > > originally... > > > > > +static void max63xx_gpio_ping(struct max63xx_wdt *wdt) > > > +{ > > > + spin_lock(&wdt->lock); > > > > Does it really need to acquire the lock? It looks like the lock is to prevent > > concurrent accesses to the mmap in max63xx_mmap_ping() and max63xx_mmap_set(). > > > > Actually, that doesn't work at all. spin_lock() directly contradicts > with gpiod_set_value_cansleep(). > > > > + gpiod_set_value_cansleep(wdt->gpio_wdi, 1); > > > + udelay(1); > > > > Doesn't it need to include <linux/delay.h> for udelay()? > > > > > @@ -225,10 +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) > > > > Use devm_gpiod_get_optional() to make the intent clear. Also, it gets rid of > > the check for -ENOENT. > > > > > + return dev_err_probe(dev, PTR_ERR(wdt->gpio_wdi), > > > + "unable to request gpio: %ld\n", > > > + PTR_ERR(wdt->gpio_wdi)); > > > > It doesn't need to again print for PTR_ERR(wdt->gpio_wdi). dev_err_probe() > > prints the error. > > > > > err = max63xx_mmap_init(pdev, wdt); > > > if (err) > > > return err; > > > + if (!IS_ERR(wdt->gpio_wdi)) > > > + wdt->ping = max63xx_gpio_ping; > > > > Thus, the max63xx_gpio_ping() overrides max63xx_mmap_ping() if the GPIO was > > provided? It would be better to mention the behavior in the commit message. > > > > Also, could both the assignments of `wdt->gpio_wdi` and `wdt->ping` happen > > after max63xx_mmap_init()? > Hello! I'm going to look at all these issues. Recently I sent max63 watchdog driver also into U-Boot and seems that I mixed DTS and driver code between U-Boot and Kernel... and tested something mixed. I will do new testing again, and will check that I'm testing correct code.
On Wednesday 04 May 2022 00:05:50 Pali Rohár wrote: > On Monday 02 May 2022 21:37:16 Guenter Roeck wrote: > > On 5/2/22 20:57, Tzung-Bi Shih wrote: > > > On Fri, Apr 29, 2022 at 03:13:49PM +0200, Pali Rohár wrote: > > > > @@ -27,6 +27,7 @@ > > > > #include <linux/io.h> > > > > #include <linux/slab.h> > > > > #include <linux/property.h> > > > > +#include <linux/gpio/consumer.h> > > > > > > It would be better to keep them alphabetically. Anyway, they aren't sorted > > > originally... > > > > > > > +static void max63xx_gpio_ping(struct max63xx_wdt *wdt) > > > > +{ > > > > + spin_lock(&wdt->lock); > > > > > > Does it really need to acquire the lock? It looks like the lock is to prevent > > > concurrent accesses to the mmap in max63xx_mmap_ping() and max63xx_mmap_set(). > > > > > > > Actually, that doesn't work at all. spin_lock() directly contradicts > > with gpiod_set_value_cansleep(). > > > > > > + gpiod_set_value_cansleep(wdt->gpio_wdi, 1); > > > > + udelay(1); > > > > > > Doesn't it need to include <linux/delay.h> for udelay()? > > > > > > > @@ -225,10 +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) > > > > > > Use devm_gpiod_get_optional() to make the intent clear. Also, it gets rid of > > > the check for -ENOENT. > > > > > > > + return dev_err_probe(dev, PTR_ERR(wdt->gpio_wdi), > > > > + "unable to request gpio: %ld\n", > > > > + PTR_ERR(wdt->gpio_wdi)); > > > > > > It doesn't need to again print for PTR_ERR(wdt->gpio_wdi). dev_err_probe() > > > prints the error. > > > > > > > err = max63xx_mmap_init(pdev, wdt); > > > > if (err) > > > > return err; > > > > + if (!IS_ERR(wdt->gpio_wdi)) > > > > + wdt->ping = max63xx_gpio_ping; > > > > > > Thus, the max63xx_gpio_ping() overrides max63xx_mmap_ping() if the GPIO was > > > provided? It would be better to mention the behavior in the commit message. > > > > > > Also, could both the assignments of `wdt->gpio_wdi` and `wdt->ping` happen > > > after max63xx_mmap_init()? > > > > Hello! I'm going to look at all these issues. Recently I sent max63 > watchdog driver also into U-Boot and seems that I mixed DTS and driver > code between U-Boot and Kernel... and tested something mixed. > > I will do new testing again, and will check that I'm testing correct > code. Hello! Now I sent a new version V3. I have tested it on PowerPC P2020 based board where watchdog registers are exported via CPLD and new V3 version is working fine.
diff --git a/drivers/watchdog/max63xx_wdt.c b/drivers/watchdog/max63xx_wdt.c index 9e1541cfae0d..6e43f9e6d7eb 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; @@ -225,10 +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) + return dev_err_probe(dev, PTR_ERR(wdt->gpio_wdi), + "unable to request gpio: %ld\n", + PTR_ERR(wdt->gpio_wdi)); + err = max63xx_mmap_init(pdev, wdt); if (err) return err; + if (!IS_ERR(wdt->gpio_wdi)) + wdt->ping = max63xx_gpio_ping; + platform_set_drvdata(pdev, &wdt->wdd); watchdog_set_drvdata(&wdt->wdd, wdt);
On some boards is WDI logic of max6370 chip connected via GPIO. So extend max63xx_wdt driver to allow specifying WDI logic via GPIO. Signed-off-by: Pali Rohár <pali@kernel.org> --- Changes in v2: * Usage of dev_err_probe() * Fixing assignment of wdt->ping * Remove clearing of wdt->gpio_wdi * Move YAML change to separate patch --- drivers/watchdog/max63xx_wdt.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+)