On Mon, Sep 28, 2015 at 09:58:44AM +0200, Jacek Anaszewski wrote: > Hi Rob. > > If you are satisfied with Simon's explanation, could you confirm > that with your ack, please? Hi Rob, Please let us know your answer. Thanks in advance. Simon > On 09/22/2015 11:30 AM, Simon Guinot wrote: > >On Mon, Sep 21, 2015 at 10:38:45AM -0500, Rob Herring wrote: > > > >Hi Rob, > > > >Thanks for your feedback. Please, see my answers below. > > > >>On 09/17/2015 10:59 AM, Simon Guinot wrote: > >>>This patch adds device tree support for the netxbig LEDs. > >>> > >>>This also introduces a additionnal DT binding for the GPIO extension bus > >>>(netxbig-gpio-ext) used to configure the LEDs. Since this bus could also > >>>be used to control other devices, then it seems more suitable to have it > >>>in a separate DT binding. > >>> > >>>Signed-off-by: Simon Guinot <simon.guinot@xxxxxxxxxxxx> > >>>Acked-by: Linus Walleij <linus.walleij@xxxxxxxxxx> > >>>--- > >>> .../devicetree/bindings/gpio/netxbig-gpio-ext.txt | 22 ++ > >>> .../devicetree/bindings/leds/leds-netxbig.txt | 92 ++++++++ > >>> drivers/leds/leds-netxbig.c | 258 +++++++++++++++++++-- > >>> include/dt-bindings/leds/leds-netxbig.h | 18 ++ > >>> 4 files changed, 369 insertions(+), 21 deletions(-) > >>> create mode 100644 Documentation/devicetree/bindings/gpio/netxbig-gpio-ext.txt > >>> create mode 100644 Documentation/devicetree/bindings/leds/leds-netxbig.txt > >>> create mode 100644 include/dt-bindings/leds/leds-netxbig.h > >>> > >>>Changes for v2: > >>>- Check timer mode value retrieved from DT. > >>>- In netxbig_leds_get_of_pdata, don't use unsigned long variables to get > >>> timer delay values from DT with function of_property_read_u32_index. > >>> Instead, use a temporary u32 variable. This allows to silence a static > >>> checker warning. > >>>- Make timer property optional in the binding documentation. It is now > >>> aligned with the driver code. > >>> > >>>Changes for v3: > >>>- Fix pointer usage with the temporary u32 variable while calling > >>> of_property_read_u32_index. > >>> > >>>Changes for v4: > >>>- In DT binding document netxbig-gpio-ext.txt, detail byte order for > >>> registers and latch mechanism for "enable-gpio". > >>>- In leds-netxbig.c, add some error messages. > >>>- In leds-netxbig.c, fix some "sizeof" style issues. > >>>- In leds-netxbig.c, in netxbig_leds_get_of_pdata(), move the > >>> of_property_read_string() calls after the error-prone checks. > >>>- Add some Acked-by. > >>> > >>>diff --git a/Documentation/devicetree/bindings/gpio/netxbig-gpio-ext.txt b/Documentation/devicetree/bindings/gpio/netxbig-gpio-ext.txt > >>>new file mode 100644 > >>>index 000000000000..50ec2e690701 > >>>--- /dev/null > >>>+++ b/Documentation/devicetree/bindings/gpio/netxbig-gpio-ext.txt > >>>@@ -0,0 +1,22 @@ > >>>+Binding for the GPIO extension bus found on some LaCie/Seagate boards > >>>+(Example: 2Big/5Big Network v2, 2Big NAS). > >>>+ > >>>+Required properties: > >>>+- compatible: "lacie,netxbig-gpio-ext". > >>>+- addr-gpios: GPIOs representing the address register (LSB -> MSB). > >>>+- data-gpios: GPIOs representing the data register (LSB -> MSB). > >>>+- enable-gpio: latches the new configuration (address, data) on raising edge. > >>>+ > >>>+Example: > >>>+ > >>>+netxbig_gpio_ext: netxbig-gpio-ext { > >>>+ compatible = "lacie,netxbig-gpio-ext"; > >>>+ > >>>+ addr-gpios = <&gpio1 15 GPIO_ACTIVE_HIGH > >>>+ &gpio1 16 GPIO_ACTIVE_HIGH > >>>+ &gpio1 17 GPIO_ACTIVE_HIGH>; > >>>+ data-gpios = <&gpio1 12 GPIO_ACTIVE_HIGH > >>>+ &gpio1 13 GPIO_ACTIVE_HIGH > >>>+ &gpio1 14 GPIO_ACTIVE_HIGH>; > >>>+ enable-gpio = <&gpio0 29 GPIO_ACTIVE_HIGH>; > >>>+}; > >>>diff --git a/Documentation/devicetree/bindings/leds/leds-netxbig.txt b/Documentation/devicetree/bindings/leds/leds-netxbig.txt > >>>new file mode 100644 > >>>index 000000000000..efadbecbfeb9 > >>>--- /dev/null > >>>+++ b/Documentation/devicetree/bindings/leds/leds-netxbig.txt > >>>@@ -0,0 +1,92 @@ > >>>+Binding for the CPLD LEDs (GPIO extension bus) found on some LaCie/Seagate > >>>+boards (Example: 2Big/5Big Network v2, 2Big NAS). > >>>+ > >>>+Required properties: > >>>+- compatible: "lacie,netxbig-leds". > >>>+- gpio-ext: Phandle for the gpio-ext bus. > >> > >>Would being a subnode of gpio-ext work instead? > > > >Well, it is really unclear to me. I think that the GPIO extension bus > >can be seen as a "kind of" GPIO chip. And devices which are using a GPIO > >resource are not represented in DT as sub-nodes of the GPIO node. That's > >why I chose to use a phandle here. > > > >Let me know if this representation is not correct. > > > >> > >>>+ > >>>+Optional properties: > >>>+- timers: Timer array. Each timer entry is represented by three integers: > >>>+ Mode (gpio-ext bus), delay_on and delay_off. > >>>+ > >>>+Each LED is represented as a sub-node of the netxbig-leds device. > >>>+ > >>>+Required sub-node properties: > >>>+- mode-addr: Mode register address on gpio-ext bus. > >>>+- mode-val: Mode to value mapping. Each entry is represented by two integers: > >>>+ A mode and the corresponding value on the gpio-ext bus. > >> > >>I somewhat wonder if this is too low level and should just be in the > >>driver instead. I guess with only 3 addr and data lines, it is okay. It > >>wouldn't scale to a large number of registers though. > > > >Even if it is not the case now, note that this values could be different > >for an another board. For example, we already have some x86-based boards > >(still no mainlined yet) which are using the leds-netxbig driver but > >with a different gpio-ext configuration. This could happen with some > >ARM-based boards too. > > > >That's why I think it is better to have this properties in the DT rather > >than hardcoded values in the driver. > > > >> > >>>+- bright-addr: Brightness register address on gpio-ext bus. > >>>+- bright-max: Maximum brightness value. > >> > >>We already have a somewhat standard max-brightness property. > > > >Yes, Jacek mentioned that too. It made the change in the v5. > > > >Thanks, > > > >Simon > > > > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
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