Messages in this thread | | | Date | Wed, 9 Mar 2016 18:50:53 +0530 | From | Laxman Dewangan <> | Subject | Re: [PATCH 4/5] gpio: of: Add support to have multiple gpios in gpio-hog |
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On Wednesday 09 March 2016 11:58 AM, Markus Pargmann wrote: > * PGP Signed by an unknown key > > Hi, > > On Tue, Mar 08, 2016 at 05:32:07PM +0530, Laxman Dewangan wrote: >> The child node for gpio hogs under gpio controller's node >> provide the mechanism to automatic GPIO request and >> configuration as part of the gpio-controller's driver >> probe function. >> >> Currently, property "gpio" takes one gpios for such >> configuration. Add support to have multiple GPIOs in >> this property so that multiple GPIOs of gpio-controller >> can be configured by this mechanism with one child node. > So if I read this correctly you want to have multiple GPIOs with the > same line name? Why don't you use multiple child nodes with individual > line names? > There is cases on which particular functional configuration needs sets of GPIO to set. On this case, making sub node for each GPIOs creates lots of sub-nodes and add complexity on readability, usability and maintainability. Example: for my board, I wanted to set GPIO H2 to input and H0 and H1 to be output high. Instead of three nodes, I can have two here: gpio@0,6000d000 { wlan_input { gpio-hog; gpios = <TEGRA_GPIO(H, 2) 0>; input; };
wlan_output { gpio-hog; gpios = <TEGRA_GPIO(H, 0) 0 TEGRA_GPIO(H, 1) 0>; output-high; }; };
So here I am grouping the multiple output GPIO together.
This looks much similar if we have many GPIOs for one type of configurations.
Even it looks better if we have something: gpio@0,6000d000 { wlan_control { gpio-hog; gpios-input = <TEGRA_GPIO(H, 2) 0>; gpios-output-high = <TEGRA_GPIO(H, 0) 0 TEGRA_GPIO(H, 1) 0>; }; };
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