| Message ID | 20220825083256.14565-6-alice.guo@oss.nxp.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | watchdog: imx7ulp_wdt: update i.MX7ULP WDOG timer driver | expand |
On Thu, Aug 25, 2022 at 04:32:54PM +0800, Alice Guo (OSS) wrote: > From: Ye Li <ye.li@nxp.com> > > Current driver may meet reconfigure failure caused by below reasons: > > 1. The wdog on iMX7ULP has different behavior after RCS valid. It needs > to wait more than 2.5 wdog clock for clock sync before next > reconfiguration, while imx8ulp wdog does not need such delay. > > 2. After unlock, there is 128 bus clock window opened for reconfiguration, > but on iMX8ULP, the HW can't guarantee the latency. So it is possible > the window is closed before the writing arrives to wdog. > > 3. If the PRES is enabled, the RCS valid time becomes x256 to the time > of PRES disabled. It is about 1715ms on iMX8ULP. So We have to increase > the RCS timeout and can't wait it in IRQ disabled. > > The patch updates the driver to handle failures > > 1. Using different wait for unlock and RCS. Unlock valid time is very short > and only related to bus clock. It must be in IRQ disabled to avoid > being interrupted in 128 clock window. But for RCS time, it is longer > and ok for IRQ enabled. > > 2. Add retry for any reconfigure failure with default 5 times. > > 3. Add "fsl,imx8ulp-wdt" compatile string for iMX8ULP and afterwards > platform which don't need more 2.5 wdog clock after RCS valid. > For imx7ulp, add post delay of 2.5 clock after RCS valid. > > Signed-off-by: Ye Li <ye.li@nxp.com> > Signed-off-by: Alice Guo <alice.guo@nxp.com> > Reviewed-by: Jacky Bai <ping.bai@nxp.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> > --- > > Changes for v2: > - the wait timeout value of the RCS is 10ms, so use the sleep_us of > readl_poll_timeout in imx7ulp_wdt_wait_rcs to avoid a 10ms hot wait > > drivers/watchdog/imx7ulp_wdt.c | 163 ++++++++++++++++++++++++++------- > 1 file changed, 129 insertions(+), 34 deletions(-) > > diff --git a/drivers/watchdog/imx7ulp_wdt.c b/drivers/watchdog/imx7ulp_wdt.c > index 12715c248688..0cafa86fff7f 100644 > --- a/drivers/watchdog/imx7ulp_wdt.c > +++ b/drivers/watchdog/imx7ulp_wdt.c > @@ -14,7 +14,9 @@ > #include <linux/watchdog.h> > > #define WDOG_CS 0x0 > +#define WDOG_CS_FLG BIT(14) > #define WDOG_CS_CMD32EN BIT(13) > +#define WDOG_CS_PRES BIT(12) > #define WDOG_CS_ULK BIT(11) > #define WDOG_CS_RCS BIT(10) > #define LPO_CLK 0x1 > @@ -39,7 +41,11 @@ > #define DEFAULT_TIMEOUT 60 > #define MAX_TIMEOUT 128 > #define WDOG_CLOCK_RATE 1000 > -#define WDOG_WAIT_TIMEOUT 10000 > +#define WDOG_ULK_WAIT_TIMEOUT 1000 > +#define WDOG_RCS_WAIT_TIMEOUT 10000 > +#define WDOG_RCS_POST_WAIT 3000 > + > +#define RETRY_MAX 5 > > static bool nowayout = WATCHDOG_NOWAYOUT; > module_param(nowayout, bool, 0000); > @@ -50,40 +56,82 @@ struct imx7ulp_wdt_device { > struct watchdog_device wdd; > void __iomem *base; > struct clk *clk; > + bool post_rcs_wait; > }; > > -static int imx7ulp_wdt_wait(void __iomem *base, u32 mask) > +static int imx7ulp_wdt_wait_ulk(void __iomem *base) > { > u32 val = readl(base + WDOG_CS); > > - if (!(val & mask) && readl_poll_timeout_atomic(base + WDOG_CS, val, > - val & mask, 0, > - WDOG_WAIT_TIMEOUT)) > + if (!(val & WDOG_CS_ULK) && > + readl_poll_timeout_atomic(base + WDOG_CS, val, > + val & WDOG_CS_ULK, 0, > + WDOG_ULK_WAIT_TIMEOUT)) > return -ETIMEDOUT; > > return 0; > } > > -static int imx7ulp_wdt_enable(struct watchdog_device *wdog, bool enable) > +static int imx7ulp_wdt_wait_rcs(struct imx7ulp_wdt_device *wdt) > { > - struct imx7ulp_wdt_device *wdt = watchdog_get_drvdata(wdog); > + int ret = 0; > + u32 val = readl(wdt->base + WDOG_CS); > + u64 timeout = (val & WDOG_CS_PRES) ? > + WDOG_RCS_WAIT_TIMEOUT * 256 : WDOG_RCS_WAIT_TIMEOUT; > + unsigned long wait_min = (val & WDOG_CS_PRES) ? > + WDOG_RCS_POST_WAIT * 256 : WDOG_RCS_POST_WAIT; > > + if (!(val & WDOG_CS_RCS) && > + readl_poll_timeout(wdt->base + WDOG_CS, val, val & WDOG_CS_RCS, 100, > + timeout)) > + ret = -ETIMEDOUT; > + > + /* Wait 2.5 clocks after RCS done */ > + if (wdt->post_rcs_wait) > + usleep_range(wait_min, wait_min + 2000); > + > + return ret; > +} > + > +static int _imx7ulp_wdt_enable(struct imx7ulp_wdt_device *wdt, bool enable) > +{ > u32 val = readl(wdt->base + WDOG_CS); > int ret; > > local_irq_disable(); > writel(UNLOCK, wdt->base + WDOG_CNT); > - ret = imx7ulp_wdt_wait(wdt->base, WDOG_CS_ULK); > + ret = imx7ulp_wdt_wait_ulk(wdt->base); > if (ret) > goto enable_out; > if (enable) > writel(val | WDOG_CS_EN, wdt->base + WDOG_CS); > else > writel(val & ~WDOG_CS_EN, wdt->base + WDOG_CS); > - ret = imx7ulp_wdt_wait(wdt->base, WDOG_CS_RCS); > + > + local_irq_enable(); > + ret = imx7ulp_wdt_wait_rcs(wdt); > + > + return ret; > > enable_out: > local_irq_enable(); > + return ret; > +} > + > +static int imx7ulp_wdt_enable(struct watchdog_device *wdog, bool enable) > +{ > + struct imx7ulp_wdt_device *wdt = watchdog_get_drvdata(wdog); > + int ret; > + u32 val; > + u32 loop = RETRY_MAX; > + > + do { > + ret = _imx7ulp_wdt_enable(wdt, enable); > + val = readl(wdt->base + WDOG_CS); > + } while (--loop > 0 && ((!!(val & WDOG_CS_EN)) != enable || ret)); > + > + if (loop == 0) > + return -EBUSY; > > return ret; > } > @@ -114,28 +162,44 @@ static int imx7ulp_wdt_stop(struct watchdog_device *wdog) > return imx7ulp_wdt_enable(wdog, false); > } > > -static int imx7ulp_wdt_set_timeout(struct watchdog_device *wdog, > - unsigned int timeout) > +static int _imx7ulp_wdt_set_timeout(struct imx7ulp_wdt_device *wdt, > + unsigned int toval) > { > - struct imx7ulp_wdt_device *wdt = watchdog_get_drvdata(wdog); > - u32 val = WDOG_CLOCK_RATE * timeout; > int ret; > > local_irq_disable(); > writel(UNLOCK, wdt->base + WDOG_CNT); > - ret = imx7ulp_wdt_wait(wdt->base, WDOG_CS_ULK); > + ret = imx7ulp_wdt_wait_ulk(wdt->base); > if (ret) > goto timeout_out; > - writel(val, wdt->base + WDOG_TOVAL); > - ret = imx7ulp_wdt_wait(wdt->base, WDOG_CS_RCS); > - if (ret) > - goto timeout_out; > - > - wdog->timeout = timeout; > + writel(toval, wdt->base + WDOG_TOVAL); > + local_irq_enable(); > + ret = imx7ulp_wdt_wait_rcs(wdt); > + return ret; > > timeout_out: > local_irq_enable(); > + return ret; > +} > > +static int imx7ulp_wdt_set_timeout(struct watchdog_device *wdog, > + unsigned int timeout) > +{ > + struct imx7ulp_wdt_device *wdt = watchdog_get_drvdata(wdog); > + u32 toval = WDOG_CLOCK_RATE * timeout; > + u32 val; > + int ret; > + u32 loop = RETRY_MAX; > + > + do { > + ret = _imx7ulp_wdt_set_timeout(wdt, toval); > + val = readl(wdt->base + WDOG_TOVAL); > + } while (--loop > 0 && (val != toval || ret)); > + > + if (loop == 0) > + return -EBUSY; > + > + wdog->timeout = timeout; > return ret; > } > > @@ -175,38 +239,59 @@ static const struct watchdog_info imx7ulp_wdt_info = { > WDIOF_MAGICCLOSE, > }; > > -static int imx7ulp_wdt_init(void __iomem *base, unsigned int timeout) > +static int _imx7ulp_wdt_init(struct imx7ulp_wdt_device *wdt, unsigned int timeout, unsigned int cs) > { > u32 val; > int ret; > > local_irq_disable(); > > - val = readl(base + WDOG_CS); > + val = readl(wdt->base + WDOG_CS); > if (val & WDOG_CS_CMD32EN) { > - writel(UNLOCK, base + WDOG_CNT); > + writel(UNLOCK, wdt->base + WDOG_CNT); > } else { > mb(); > /* unlock the wdog for reconfiguration */ > - writel_relaxed(UNLOCK_SEQ0, base + WDOG_CNT); > - writel_relaxed(UNLOCK_SEQ1, base + WDOG_CNT); > + writel_relaxed(UNLOCK_SEQ0, wdt->base + WDOG_CNT); > + writel_relaxed(UNLOCK_SEQ1, wdt->base + WDOG_CNT); > mb(); > } > > - ret = imx7ulp_wdt_wait(base, WDOG_CS_ULK); > + ret = imx7ulp_wdt_wait_ulk(wdt->base); > if (ret) > goto init_out; > > /* set an initial timeout value in TOVAL */ > - writel(timeout, base + WDOG_TOVAL); > - /* enable 32bit command sequence and reconfigure */ > - val = WDOG_CS_CMD32EN | WDOG_CS_CLK | WDOG_CS_UPDATE | > - WDOG_CS_WAIT | WDOG_CS_STOP; > - writel(val, base + WDOG_CS); > - imx7ulp_wdt_wait(base, WDOG_CS_RCS); > + writel(timeout, wdt->base + WDOG_TOVAL); > + writel(cs, wdt->base + WDOG_CS); > + local_irq_enable(); > + ret = imx7ulp_wdt_wait_rcs(wdt); > + > + return ret; > > init_out: > local_irq_enable(); > + return ret; > +} > + > +static int imx7ulp_wdt_init(struct imx7ulp_wdt_device *wdt, unsigned int timeout) > +{ > + /* enable 32bit command sequence and reconfigure */ > + u32 val = WDOG_CS_CMD32EN | WDOG_CS_CLK | WDOG_CS_UPDATE | > + WDOG_CS_WAIT | WDOG_CS_STOP; > + u32 cs, toval; > + int ret; > + u32 loop = RETRY_MAX; > + > + do { > + ret = _imx7ulp_wdt_init(wdt, timeout, val); > + toval = readl(wdt->base + WDOG_TOVAL); > + cs = readl(wdt->base + WDOG_CS); > + cs &= ~(WDOG_CS_FLG | WDOG_CS_ULK | WDOG_CS_RCS); > + } while (--loop > 0 && (cs != val || toval != timeout || ret)); > + > + if (loop == 0) > + return -EBUSY; > > return ret; > } > @@ -239,6 +324,15 @@ static int imx7ulp_wdt_probe(struct platform_device *pdev) > return PTR_ERR(imx7ulp_wdt->clk); > } > > + imx7ulp_wdt->post_rcs_wait = true; > + if (of_device_is_compatible(dev->of_node, > + "fsl,imx8ulp-wdt")) { > + dev_info(dev, "imx8ulp wdt probe\n"); > + imx7ulp_wdt->post_rcs_wait = false; > + } else { > + dev_info(dev, "imx7ulp wdt probe\n"); > + } > + > ret = clk_prepare_enable(imx7ulp_wdt->clk); > if (ret) > return ret; > @@ -259,7 +353,7 @@ static int imx7ulp_wdt_probe(struct platform_device *pdev) > watchdog_stop_on_reboot(wdog); > watchdog_stop_on_unregister(wdog); > watchdog_set_drvdata(wdog, imx7ulp_wdt); > - ret = imx7ulp_wdt_init(imx7ulp_wdt->base, wdog->timeout * WDOG_CLOCK_RATE); > + ret = imx7ulp_wdt_init(imx7ulp_wdt, wdog->timeout * WDOG_CLOCK_RATE); > if (ret) > return ret; > > @@ -289,7 +383,7 @@ static int __maybe_unused imx7ulp_wdt_resume_noirq(struct device *dev) > return ret; > > if (imx7ulp_wdt_is_enabled(imx7ulp_wdt->base)) > - imx7ulp_wdt_init(imx7ulp_wdt->base, timeout); > + imx7ulp_wdt_init(imx7ulp_wdt, timeout); > > if (watchdog_active(&imx7ulp_wdt->wdd)) > imx7ulp_wdt_start(&imx7ulp_wdt->wdd); > @@ -303,6 +397,7 @@ static const struct dev_pm_ops imx7ulp_wdt_pm_ops = { > }; > > static const struct of_device_id imx7ulp_wdt_dt_ids[] = { > + { .compatible = "fsl,imx8ulp-wdt", }, > { .compatible = "fsl,imx7ulp-wdt", }, > { /* sentinel */ } > }; > -- > 2.17.1 >
diff --git a/drivers/watchdog/imx7ulp_wdt.c b/drivers/watchdog/imx7ulp_wdt.c index 12715c248688..0cafa86fff7f 100644 --- a/drivers/watchdog/imx7ulp_wdt.c +++ b/drivers/watchdog/imx7ulp_wdt.c @@ -14,7 +14,9 @@ #include <linux/watchdog.h> #define WDOG_CS 0x0 +#define WDOG_CS_FLG BIT(14) #define WDOG_CS_CMD32EN BIT(13) +#define WDOG_CS_PRES BIT(12) #define WDOG_CS_ULK BIT(11) #define WDOG_CS_RCS BIT(10) #define LPO_CLK 0x1 @@ -39,7 +41,11 @@ #define DEFAULT_TIMEOUT 60 #define MAX_TIMEOUT 128 #define WDOG_CLOCK_RATE 1000 -#define WDOG_WAIT_TIMEOUT 10000 +#define WDOG_ULK_WAIT_TIMEOUT 1000 +#define WDOG_RCS_WAIT_TIMEOUT 10000 +#define WDOG_RCS_POST_WAIT 3000 + +#define RETRY_MAX 5 static bool nowayout = WATCHDOG_NOWAYOUT; module_param(nowayout, bool, 0000); @@ -50,40 +56,82 @@ struct imx7ulp_wdt_device { struct watchdog_device wdd; void __iomem *base; struct clk *clk; + bool post_rcs_wait; }; -static int imx7ulp_wdt_wait(void __iomem *base, u32 mask) +static int imx7ulp_wdt_wait_ulk(void __iomem *base) { u32 val = readl(base + WDOG_CS); - if (!(val & mask) && readl_poll_timeout_atomic(base + WDOG_CS, val, - val & mask, 0, - WDOG_WAIT_TIMEOUT)) + if (!(val & WDOG_CS_ULK) && + readl_poll_timeout_atomic(base + WDOG_CS, val, + val & WDOG_CS_ULK, 0, + WDOG_ULK_WAIT_TIMEOUT)) return -ETIMEDOUT; return 0; } -static int imx7ulp_wdt_enable(struct watchdog_device *wdog, bool enable) +static int imx7ulp_wdt_wait_rcs(struct imx7ulp_wdt_device *wdt) { - struct imx7ulp_wdt_device *wdt = watchdog_get_drvdata(wdog); + int ret = 0; + u32 val = readl(wdt->base + WDOG_CS); + u64 timeout = (val & WDOG_CS_PRES) ? + WDOG_RCS_WAIT_TIMEOUT * 256 : WDOG_RCS_WAIT_TIMEOUT; + unsigned long wait_min = (val & WDOG_CS_PRES) ? + WDOG_RCS_POST_WAIT * 256 : WDOG_RCS_POST_WAIT; + if (!(val & WDOG_CS_RCS) && + readl_poll_timeout(wdt->base + WDOG_CS, val, val & WDOG_CS_RCS, 100, + timeout)) + ret = -ETIMEDOUT; + + /* Wait 2.5 clocks after RCS done */ + if (wdt->post_rcs_wait) + usleep_range(wait_min, wait_min + 2000); + + return ret; +} + +static int _imx7ulp_wdt_enable(struct imx7ulp_wdt_device *wdt, bool enable) +{ u32 val = readl(wdt->base + WDOG_CS); int ret; local_irq_disable(); writel(UNLOCK, wdt->base + WDOG_CNT); - ret = imx7ulp_wdt_wait(wdt->base, WDOG_CS_ULK); + ret = imx7ulp_wdt_wait_ulk(wdt->base); if (ret) goto enable_out; if (enable) writel(val | WDOG_CS_EN, wdt->base + WDOG_CS); else writel(val & ~WDOG_CS_EN, wdt->base + WDOG_CS); - ret = imx7ulp_wdt_wait(wdt->base, WDOG_CS_RCS); + + local_irq_enable(); + ret = imx7ulp_wdt_wait_rcs(wdt); + + return ret; enable_out: local_irq_enable(); + return ret; +} + +static int imx7ulp_wdt_enable(struct watchdog_device *wdog, bool enable) +{ + struct imx7ulp_wdt_device *wdt = watchdog_get_drvdata(wdog); + int ret; + u32 val; + u32 loop = RETRY_MAX; + + do { + ret = _imx7ulp_wdt_enable(wdt, enable); + val = readl(wdt->base + WDOG_CS); + } while (--loop > 0 && ((!!(val & WDOG_CS_EN)) != enable || ret)); + + if (loop == 0) + return -EBUSY; return ret; } @@ -114,28 +162,44 @@ static int imx7ulp_wdt_stop(struct watchdog_device *wdog) return imx7ulp_wdt_enable(wdog, false); } -static int imx7ulp_wdt_set_timeout(struct watchdog_device *wdog, - unsigned int timeout) +static int _imx7ulp_wdt_set_timeout(struct imx7ulp_wdt_device *wdt, + unsigned int toval) { - struct imx7ulp_wdt_device *wdt = watchdog_get_drvdata(wdog); - u32 val = WDOG_CLOCK_RATE * timeout; int ret; local_irq_disable(); writel(UNLOCK, wdt->base + WDOG_CNT); - ret = imx7ulp_wdt_wait(wdt->base, WDOG_CS_ULK); + ret = imx7ulp_wdt_wait_ulk(wdt->base); if (ret) goto timeout_out; - writel(val, wdt->base + WDOG_TOVAL); - ret = imx7ulp_wdt_wait(wdt->base, WDOG_CS_RCS); - if (ret) - goto timeout_out; - - wdog->timeout = timeout; + writel(toval, wdt->base + WDOG_TOVAL); + local_irq_enable(); + ret = imx7ulp_wdt_wait_rcs(wdt); + return ret; timeout_out: local_irq_enable(); + return ret; +} +static int imx7ulp_wdt_set_timeout(struct watchdog_device *wdog, + unsigned int timeout) +{ + struct imx7ulp_wdt_device *wdt = watchdog_get_drvdata(wdog); + u32 toval = WDOG_CLOCK_RATE * timeout; + u32 val; + int ret; + u32 loop = RETRY_MAX; + + do { + ret = _imx7ulp_wdt_set_timeout(wdt, toval); + val = readl(wdt->base + WDOG_TOVAL); + } while (--loop > 0 && (val != toval || ret)); + + if (loop == 0) + return -EBUSY; + + wdog->timeout = timeout; return ret; } @@ -175,38 +239,59 @@ static const struct watchdog_info imx7ulp_wdt_info = { WDIOF_MAGICCLOSE, }; -static int imx7ulp_wdt_init(void __iomem *base, unsigned int timeout) +static int _imx7ulp_wdt_init(struct imx7ulp_wdt_device *wdt, unsigned int timeout, unsigned int cs) { u32 val; int ret; local_irq_disable(); - val = readl(base + WDOG_CS); + val = readl(wdt->base + WDOG_CS); if (val & WDOG_CS_CMD32EN) { - writel(UNLOCK, base + WDOG_CNT); + writel(UNLOCK, wdt->base + WDOG_CNT); } else { mb(); /* unlock the wdog for reconfiguration */ - writel_relaxed(UNLOCK_SEQ0, base + WDOG_CNT); - writel_relaxed(UNLOCK_SEQ1, base + WDOG_CNT); + writel_relaxed(UNLOCK_SEQ0, wdt->base + WDOG_CNT); + writel_relaxed(UNLOCK_SEQ1, wdt->base + WDOG_CNT); mb(); } - ret = imx7ulp_wdt_wait(base, WDOG_CS_ULK); + ret = imx7ulp_wdt_wait_ulk(wdt->base); if (ret) goto init_out; /* set an initial timeout value in TOVAL */ - writel(timeout, base + WDOG_TOVAL); - /* enable 32bit command sequence and reconfigure */ - val = WDOG_CS_CMD32EN | WDOG_CS_CLK | WDOG_CS_UPDATE | - WDOG_CS_WAIT | WDOG_CS_STOP; - writel(val, base + WDOG_CS); - imx7ulp_wdt_wait(base, WDOG_CS_RCS); + writel(timeout, wdt->base + WDOG_TOVAL); + writel(cs, wdt->base + WDOG_CS); + local_irq_enable(); + ret = imx7ulp_wdt_wait_rcs(wdt); + + return ret; init_out: local_irq_enable(); + return ret; +} + +static int imx7ulp_wdt_init(struct imx7ulp_wdt_device *wdt, unsigned int timeout) +{ + /* enable 32bit command sequence and reconfigure */ + u32 val = WDOG_CS_CMD32EN | WDOG_CS_CLK | WDOG_CS_UPDATE | + WDOG_CS_WAIT | WDOG_CS_STOP; + u32 cs, toval; + int ret; + u32 loop = RETRY_MAX; + + do { + ret = _imx7ulp_wdt_init(wdt, timeout, val); + toval = readl(wdt->base + WDOG_TOVAL); + cs = readl(wdt->base + WDOG_CS); + cs &= ~(WDOG_CS_FLG | WDOG_CS_ULK | WDOG_CS_RCS); + } while (--loop > 0 && (cs != val || toval != timeout || ret)); + + if (loop == 0) + return -EBUSY; return ret; } @@ -239,6 +324,15 @@ static int imx7ulp_wdt_probe(struct platform_device *pdev) return PTR_ERR(imx7ulp_wdt->clk); } + imx7ulp_wdt->post_rcs_wait = true; + if (of_device_is_compatible(dev->of_node, + "fsl,imx8ulp-wdt")) { + dev_info(dev, "imx8ulp wdt probe\n"); + imx7ulp_wdt->post_rcs_wait = false; + } else { + dev_info(dev, "imx7ulp wdt probe\n"); + } + ret = clk_prepare_enable(imx7ulp_wdt->clk); if (ret) return ret; @@ -259,7 +353,7 @@ static int imx7ulp_wdt_probe(struct platform_device *pdev) watchdog_stop_on_reboot(wdog); watchdog_stop_on_unregister(wdog); watchdog_set_drvdata(wdog, imx7ulp_wdt); - ret = imx7ulp_wdt_init(imx7ulp_wdt->base, wdog->timeout * WDOG_CLOCK_RATE); + ret = imx7ulp_wdt_init(imx7ulp_wdt, wdog->timeout * WDOG_CLOCK_RATE); if (ret) return ret; @@ -289,7 +383,7 @@ static int __maybe_unused imx7ulp_wdt_resume_noirq(struct device *dev) return ret; if (imx7ulp_wdt_is_enabled(imx7ulp_wdt->base)) - imx7ulp_wdt_init(imx7ulp_wdt->base, timeout); + imx7ulp_wdt_init(imx7ulp_wdt, timeout); if (watchdog_active(&imx7ulp_wdt->wdd)) imx7ulp_wdt_start(&imx7ulp_wdt->wdd); @@ -303,6 +397,7 @@ static const struct dev_pm_ops imx7ulp_wdt_pm_ops = { }; static const struct of_device_id imx7ulp_wdt_dt_ids[] = { + { .compatible = "fsl,imx8ulp-wdt", }, { .compatible = "fsl,imx7ulp-wdt", }, { /* sentinel */ } };