| Message ID | 20181130202743.20585-2-eric@anholt.net (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | BCM2835 PM driver (MFD version respin) | expand |
On Fri, 30 Nov 2018 12:27:39 -0800, Eric Anholt wrote: > This binding supersedes the bcm2835-pm-wdt binding which only covered > enough to provide a watchdog, but the HW block is actually mostly > about power domains. > > Signed-off-by: Eric Anholt <eric@anholt.net> > --- > .../bindings/soc/bcm/brcm,bcm2835-pm.txt | 42 +++++++++++++++++++ > 1 file changed, 42 insertions(+) > create mode 100644 Documentation/devicetree/bindings/soc/bcm/brcm,bcm2835-pm.txt > Reviewed-by: Rob Herring <robh@kernel.org>
Hi Eric, [add Sebastian] > Eric Anholt <eric@anholt.net> hat am 30. November 2018 um 21:27 geschrieben: > > > This binding supersedes the bcm2835-pm-wdt binding which only covered > enough to provide a watchdog, but the HW block is actually mostly > about power domains. > > Signed-off-by: Eric Anholt <eric@anholt.net> > --- > .../bindings/soc/bcm/brcm,bcm2835-pm.txt | 42 +++++++++++++++++++ > 1 file changed, 42 insertions(+) > create mode 100644 Documentation/devicetree/bindings/soc/bcm/brcm,bcm2835-pm.txt > > diff --git a/Documentation/devicetree/bindings/soc/bcm/brcm,bcm2835-pm.txt b/Documentation/devicetree/bindings/soc/bcm/brcm,bcm2835-pm.txt > new file mode 100644 > index 000000000000..7818d33a158f > --- /dev/null > +++ b/Documentation/devicetree/bindings/soc/bcm/brcm,bcm2835-pm.txt > @@ -0,0 +1,42 @@ > +BCM2835 PM (Power domains, watchdog) > + > +The PM block controls power domains and some reset lines, and includes > +a watchdog timer. This binding supersedes the brcm,bcm2835-pm-wdt > +binding which covered some of PM's register range and functionality. > + > +Required properties: > + > +- compatible: Should be "brcm,bcm2835-pm" > +- reg: Specifies base physical address and size of the two > + register ranges ("PM" and "ASYNC_BRIDGE" in that > + order) > +- clocks: a) v3d: The V3D clock from CPRMAN > + b) peri_image: The PERI_IMAGE clock from CPRMAN > + c) h264: The H264 clock from CPRMAN > + d) isp: The ISP clock from CPRMAN > +- #reset-cells: Should be 1. This property follows the reset controller > + bindings[1]. > +- #power-domain-cells: Should be 1. This property follows the power domain > + bindings[2]. > + > +Optional properties: > + > +- timeout-sec: Contains the watchdog timeout in seconds > + > +[1] Documentation/devicetree/bindings/reset/reset.txt > +[2] Documentation/devicetree/bindings/power/power_domain.txt > + sorry for my late reply. I hope we can take the opportunity of a new binding to fix an old issue of the bcm2835-wdt driver. The watchdog driver sets the pm_power_off callback without checking for "system-power-controller" property [3]. As a result we can't use another poweroff controller like e.g. gpio-poweroff. In downstream this has been workarounded by an additional devicetree property for the gpio-poweroff driver [4]. But this isn't the right way because the issue is in the bcm2835 watchdog driver not in all the other reset controller. Suggested pseudo code: if (!pm_power_off) { /* Preserve the old behavior of watchdog driver in case of old DTB */ if (!of_device_is_compatible(dev->of.node, "brcm,bcm2835-pm") || of_device_is_system_power_controller(dev->of.node)) pm_power_off = bcm2835_power_off; } Best regards Stefan [3] - https://elixir.bootlin.com/linux/latest/source/Documentation/devicetree/bindings/power/power-controller.txt [4] - https://github.com/raspberrypi/linux/commit/f86dcfac0a4e478fee40b5a3729ff1b159ae91ee
diff --git a/Documentation/devicetree/bindings/soc/bcm/brcm,bcm2835-pm.txt b/Documentation/devicetree/bindings/soc/bcm/brcm,bcm2835-pm.txt new file mode 100644 index 000000000000..7818d33a158f --- /dev/null +++ b/Documentation/devicetree/bindings/soc/bcm/brcm,bcm2835-pm.txt @@ -0,0 +1,42 @@ +BCM2835 PM (Power domains, watchdog) + +The PM block controls power domains and some reset lines, and includes +a watchdog timer. This binding supersedes the brcm,bcm2835-pm-wdt +binding which covered some of PM's register range and functionality. + +Required properties: + +- compatible: Should be "brcm,bcm2835-pm" +- reg: Specifies base physical address and size of the two + register ranges ("PM" and "ASYNC_BRIDGE" in that + order) +- clocks: a) v3d: The V3D clock from CPRMAN + b) peri_image: The PERI_IMAGE clock from CPRMAN + c) h264: The H264 clock from CPRMAN + d) isp: The ISP clock from CPRMAN +- #reset-cells: Should be 1. This property follows the reset controller + bindings[1]. +- #power-domain-cells: Should be 1. This property follows the power domain + bindings[2]. + +Optional properties: + +- timeout-sec: Contains the watchdog timeout in seconds + +[1] Documentation/devicetree/bindings/reset/reset.txt +[2] Documentation/devicetree/bindings/power/power_domain.txt + +Example: + +pm { + compatible = "brcm,bcm2835-pm", "brcm,bcm2835-pm-wdt"; + #power-domain-cells = <1>; + #reset-cells = <1>; + reg = <0x7e100000 0x114>, + <0x7e00a000 0x24>; + clocks = <&clocks BCM2835_CLOCK_V3D>, + <&clocks BCM2835_CLOCK_PERI_IMAGE>, + <&clocks BCM2835_CLOCK_H264>, + <&clocks BCM2835_CLOCK_ISP>; + clock-names = "v3d", "peri_image", "h264", "isp"; +};
This binding supersedes the bcm2835-pm-wdt binding which only covered enough to provide a watchdog, but the HW block is actually mostly about power domains. Signed-off-by: Eric Anholt <eric@anholt.net> --- .../bindings/soc/bcm/brcm,bcm2835-pm.txt | 42 +++++++++++++++++++ 1 file changed, 42 insertions(+) create mode 100644 Documentation/devicetree/bindings/soc/bcm/brcm,bcm2835-pm.txt