| Message ID | 20200417170825.2551367-2-thierry.reding@gmail.com |
|---|---|
| State | Deferred |
| Headers | show |
| Series | [1/3] dt-bindings: mfd: Document the RTC present on MAX77620 | expand |
On 17/04/2020 18:08, Thierry Reding wrote: > From: Thierry Reding <treding@nvidia.com> > > Use the standard "wakeup-source" device tree property to determine if > the RTC can act as a wakeup source for the system. Note that the driver > by default always assumes that the RTC can act as a wakeup source, but > whether it can really do so or not always depends on how it is hooked > up. > > In order to preserve backwards compatibility with older device trees, > only parse the "wakeup-source" property when a device tree node was > associated with the RTC device. This doesn't typically happen because > the top-level MFD driver doesn't list any compatible strings that can > be used to map child nodes to child devices. As a fallback, check if a > child node named "rtc" exists and use that instead. > > Signed-off-by: Thierry Reding <treding@nvidia.com> > --- > Note that we could obviously add support to the MFD driver to match > subdevices to their device tree nodes by compatible string, but there > are side-effects, such as the driver core complaining about the lack > of a DMA mask for these devices. That in turn could also be fixed but > it ends up all being rather hacky, so just looking up a child node by > name seems like a good compromise, especially since there are already > such subnodes for some of the other subdevices of this PMIC. > --- > drivers/rtc/rtc-max77686.c | 18 +++++++++++++++++- > 1 file changed, 17 insertions(+), 1 deletion(-) > > diff --git a/drivers/rtc/rtc-max77686.c b/drivers/rtc/rtc-max77686.c > index d5a0e27dd0a0..35fd74b83626 100644 > --- a/drivers/rtc/rtc-max77686.c > +++ b/drivers/rtc/rtc-max77686.c > @@ -722,6 +722,8 @@ static int max77686_rtc_probe(struct platform_device *pdev) > { > struct max77686_rtc_info *info; > const struct platform_device_id *id = platform_get_device_id(pdev); > + struct device_node *np = of_node_get(pdev->dev.of_node); > + bool wakeup = true; > int ret; > > info = devm_kzalloc(&pdev->dev, sizeof(struct max77686_rtc_info), > @@ -746,7 +748,21 @@ static int max77686_rtc_probe(struct platform_device *pdev) > goto err_rtc; > } > > - device_init_wakeup(&pdev->dev, 1); > + /* > + * Only check for the wakeup-source property if there's an actual > + * device tree node for the RTC. If no device tree node had been > + * attached during device instantiation, try looking up the "rtc" > + * child node of the parent's device tree node. > + */ > + if (!np && pdev->dev.parent->of_node) > + np = of_get_child_by_name(pdev->dev.parent->of_node, "rtc"); > + > + if (np) { > + wakeup = of_property_read_bool(np, "wakeup-source"); > + of_node_put(np); > + } > + > + device_init_wakeup(&pdev->dev, wakeup); > > info->rtc_dev = devm_rtc_device_register(&pdev->dev, id->name, > &max77686_rtc_ops, THIS_MODULE); > Acked-by: Jon Hunter <jonathanh@nvidia.com> Tested-by: Jon Hunter <jonathanh@nvidia.com> Cheers Jon
diff --git a/drivers/rtc/rtc-max77686.c b/drivers/rtc/rtc-max77686.c index d5a0e27dd0a0..35fd74b83626 100644 --- a/drivers/rtc/rtc-max77686.c +++ b/drivers/rtc/rtc-max77686.c @@ -722,6 +722,8 @@ static int max77686_rtc_probe(struct platform_device *pdev) { struct max77686_rtc_info *info; const struct platform_device_id *id = platform_get_device_id(pdev); + struct device_node *np = of_node_get(pdev->dev.of_node); + bool wakeup = true; int ret; info = devm_kzalloc(&pdev->dev, sizeof(struct max77686_rtc_info), @@ -746,7 +748,21 @@ static int max77686_rtc_probe(struct platform_device *pdev) goto err_rtc; } - device_init_wakeup(&pdev->dev, 1); + /* + * Only check for the wakeup-source property if there's an actual + * device tree node for the RTC. If no device tree node had been + * attached during device instantiation, try looking up the "rtc" + * child node of the parent's device tree node. + */ + if (!np && pdev->dev.parent->of_node) + np = of_get_child_by_name(pdev->dev.parent->of_node, "rtc"); + + if (np) { + wakeup = of_property_read_bool(np, "wakeup-source"); + of_node_put(np); + } + + device_init_wakeup(&pdev->dev, wakeup); info->rtc_dev = devm_rtc_device_register(&pdev->dev, id->name, &max77686_rtc_ops, THIS_MODULE);