| Message ID | 20220825083256.14565-8-alice.guo@oss.nxp.com (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | watchdog: imx7ulp_wdt: update i.MX7ULP WDOG timer driver | expand |
On Thu, Aug 25, 2022 at 04:32:56PM +0800, Alice Guo (OSS) wrote: > From: Alice Guo <alice.guo@nxp.com> > > The WDOG clocks are sourced from lpo_clk, and lpo_clk is the fixed > 32KHz. TOVAL contains the 16-bit value used to set the timeout period of > the watchdog. When the timeout period exceeds 2 seconds, the value > written to the TOVAL register is larger than 16-bit can represent. > Enabling watchdog prescaler can solve this problem. > > Two points need to be aware of: > 1. watchdog prescaler enables a fixed 256 pre-scaling of watchdog > counter reference clock > 2. reconfiguration takes about 55ms on imx93 > > Reviewed-by: Jacky Bai <ping.bai@nxp.com> > Signed-off-by: Alice Guo <alice.guo@nxp.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> > --- > > Changes for v2: > - none > > drivers/watchdog/imx7ulp_wdt.c | 33 ++++++++++++++++++++++++++++----- > 1 file changed, 28 insertions(+), 5 deletions(-) > > diff --git a/drivers/watchdog/imx7ulp_wdt.c b/drivers/watchdog/imx7ulp_wdt.c > index dee02c2a52c9..2897902090b3 100644 > --- a/drivers/watchdog/imx7ulp_wdt.c > +++ b/drivers/watchdog/imx7ulp_wdt.c > @@ -9,6 +9,7 @@ > #include <linux/kernel.h> > #include <linux/module.h> > #include <linux/of.h> > +#include <linux/of_device.h> > #include <linux/platform_device.h> > #include <linux/reboot.h> > #include <linux/watchdog.h> > @@ -52,11 +53,17 @@ module_param(nowayout, bool, 0000); > MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" > __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); > > +struct imx_wdt_hw_feature { > + bool prescaler_enable; > + u32 wdog_clock_rate; > +}; > + > struct imx7ulp_wdt_device { > struct watchdog_device wdd; > void __iomem *base; > struct clk *clk; > bool post_rcs_wait; > + const struct imx_wdt_hw_feature *hw; > }; > > static int imx7ulp_wdt_wait_ulk(void __iomem *base) > @@ -179,7 +186,7 @@ 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 toval = wdt->hw->wdog_clock_rate * timeout; > u32 val; > int ret; > u32 loop = RETRY_MAX; > @@ -276,6 +283,9 @@ static int imx7ulp_wdt_init(struct imx7ulp_wdt_device *wdt, unsigned int timeout > int ret; > u32 loop = RETRY_MAX; > > + if (wdt->hw->prescaler_enable) > + val |= WDOG_CS_PRES; > + > do { > ret = _imx7ulp_wdt_init(wdt, timeout, val); > toval = readl(wdt->base + WDOG_TOVAL); > @@ -346,7 +356,9 @@ 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, wdog->timeout * WDOG_CLOCK_RATE); > + > + imx7ulp_wdt->hw = of_device_get_match_data(dev); > + ret = imx7ulp_wdt_init(imx7ulp_wdt, wdog->timeout * imx7ulp_wdt->hw->wdog_clock_rate); > if (ret) > return ret; > > @@ -368,7 +380,7 @@ static int __maybe_unused imx7ulp_wdt_suspend_noirq(struct device *dev) > static int __maybe_unused imx7ulp_wdt_resume_noirq(struct device *dev) > { > struct imx7ulp_wdt_device *imx7ulp_wdt = dev_get_drvdata(dev); > - u32 timeout = imx7ulp_wdt->wdd.timeout * WDOG_CLOCK_RATE; > + u32 timeout = imx7ulp_wdt->wdd.timeout * imx7ulp_wdt->hw->wdog_clock_rate; > int ret; > > ret = clk_prepare_enable(imx7ulp_wdt->clk); > @@ -389,9 +401,20 @@ static const struct dev_pm_ops imx7ulp_wdt_pm_ops = { > imx7ulp_wdt_resume_noirq) > }; > > +static const struct imx_wdt_hw_feature imx7ulp_wdt_hw = { > + .prescaler_enable = false, > + .wdog_clock_rate = 1000, > +}; > + > +static const struct imx_wdt_hw_feature imx93_wdt_hw = { > + .prescaler_enable = true, > + .wdog_clock_rate = 125, > +}; > + > static const struct of_device_id imx7ulp_wdt_dt_ids[] = { > - { .compatible = "fsl,imx8ulp-wdt", }, > - { .compatible = "fsl,imx7ulp-wdt", }, > + { .compatible = "fsl,imx8ulp-wdt", .data = &imx7ulp_wdt_hw, }, > + { .compatible = "fsl,imx7ulp-wdt", .data = &imx7ulp_wdt_hw, }, > + { .compatible = "fsl,imx93-wdt", .data = &imx93_wdt_hw, }, > { /* sentinel */ } > }; > MODULE_DEVICE_TABLE(of, imx7ulp_wdt_dt_ids); > -- > 2.17.1 >
diff --git a/drivers/watchdog/imx7ulp_wdt.c b/drivers/watchdog/imx7ulp_wdt.c index dee02c2a52c9..2897902090b3 100644 --- a/drivers/watchdog/imx7ulp_wdt.c +++ b/drivers/watchdog/imx7ulp_wdt.c @@ -9,6 +9,7 @@ #include <linux/kernel.h> #include <linux/module.h> #include <linux/of.h> +#include <linux/of_device.h> #include <linux/platform_device.h> #include <linux/reboot.h> #include <linux/watchdog.h> @@ -52,11 +53,17 @@ module_param(nowayout, bool, 0000); MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); +struct imx_wdt_hw_feature { + bool prescaler_enable; + u32 wdog_clock_rate; +}; + struct imx7ulp_wdt_device { struct watchdog_device wdd; void __iomem *base; struct clk *clk; bool post_rcs_wait; + const struct imx_wdt_hw_feature *hw; }; static int imx7ulp_wdt_wait_ulk(void __iomem *base) @@ -179,7 +186,7 @@ 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 toval = wdt->hw->wdog_clock_rate * timeout; u32 val; int ret; u32 loop = RETRY_MAX; @@ -276,6 +283,9 @@ static int imx7ulp_wdt_init(struct imx7ulp_wdt_device *wdt, unsigned int timeout int ret; u32 loop = RETRY_MAX; + if (wdt->hw->prescaler_enable) + val |= WDOG_CS_PRES; + do { ret = _imx7ulp_wdt_init(wdt, timeout, val); toval = readl(wdt->base + WDOG_TOVAL); @@ -346,7 +356,9 @@ 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, wdog->timeout * WDOG_CLOCK_RATE); + + imx7ulp_wdt->hw = of_device_get_match_data(dev); + ret = imx7ulp_wdt_init(imx7ulp_wdt, wdog->timeout * imx7ulp_wdt->hw->wdog_clock_rate); if (ret) return ret; @@ -368,7 +380,7 @@ static int __maybe_unused imx7ulp_wdt_suspend_noirq(struct device *dev) static int __maybe_unused imx7ulp_wdt_resume_noirq(struct device *dev) { struct imx7ulp_wdt_device *imx7ulp_wdt = dev_get_drvdata(dev); - u32 timeout = imx7ulp_wdt->wdd.timeout * WDOG_CLOCK_RATE; + u32 timeout = imx7ulp_wdt->wdd.timeout * imx7ulp_wdt->hw->wdog_clock_rate; int ret; ret = clk_prepare_enable(imx7ulp_wdt->clk); @@ -389,9 +401,20 @@ static const struct dev_pm_ops imx7ulp_wdt_pm_ops = { imx7ulp_wdt_resume_noirq) }; +static const struct imx_wdt_hw_feature imx7ulp_wdt_hw = { + .prescaler_enable = false, + .wdog_clock_rate = 1000, +}; + +static const struct imx_wdt_hw_feature imx93_wdt_hw = { + .prescaler_enable = true, + .wdog_clock_rate = 125, +}; + static const struct of_device_id imx7ulp_wdt_dt_ids[] = { - { .compatible = "fsl,imx8ulp-wdt", }, - { .compatible = "fsl,imx7ulp-wdt", }, + { .compatible = "fsl,imx8ulp-wdt", .data = &imx7ulp_wdt_hw, }, + { .compatible = "fsl,imx7ulp-wdt", .data = &imx7ulp_wdt_hw, }, + { .compatible = "fsl,imx93-wdt", .data = &imx93_wdt_hw, }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(of, imx7ulp_wdt_dt_ids);