| Message ID | 1412717576-19737-3-git-send-email-b.galvani@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Oct 7, 2014 at 11:32 PM, Beniamino Galvani <b.galvani@gmail.com> wrote: > Add device tree bindings documentation for Amlogic Meson pinmux and > GPIO controller. > > Signed-off-by: Beniamino Galvani <b.galvani@gmail.com> (...) > +Required properties for gpio sub-nodes: > + - reg: should contain address and size for mux, pull-enable, pull and > + gpio register sets > + - reg-names: an array of strings describing the "reg" entries. Must > + contain "mux", "pull" and "gpio". "pull-enable" is optional and > + when it is missing the "pull" registers are used instead So it seems segmenting the registers is done to sort of control the hardware versioning. I think it's better to use the compatible string to indicate different versions of the hardware and then have just have one big regs to cover all registers. > +Valid gpio sub-nodes name are: > + - "banks" for the standard banks > + - "ao-bank" for the AO bank which belong to the special always-on > + power domain I think it's unnecessary to split up banks, the compatible property should be enough to know how many banks this controller has and where they are located in relation to the base offset. > +Required properties for configuration nodes: > + - pins: the name of a pin group. The list of all available groups can > + be found in driver sources. > + - function: the name of a function to activate for the specified set > + of groups. The list of all available functions can be found in > + driver sources. This is interesting. I have established that for controllers mapping functions to groups we use "function" and "groups". So for per-pin configuration, "function" and "pins" would be apropriate. Yours, Linus Walleij
On Fri, Oct 24, 2014 at 01:53:28PM +0200, Linus Walleij wrote: > On Tue, Oct 7, 2014 at 11:32 PM, Beniamino Galvani <b.galvani@gmail.com> wrote: > > > Add device tree bindings documentation for Amlogic Meson pinmux and > > GPIO controller. > > > > Signed-off-by: Beniamino Galvani <b.galvani@gmail.com> > (...) > > +Required properties for gpio sub-nodes: > > + - reg: should contain address and size for mux, pull-enable, pull and > > + gpio register sets > > + - reg-names: an array of strings describing the "reg" entries. Must > > + contain "mux", "pull" and "gpio". "pull-enable" is optional and > > + when it is missing the "pull" registers are used instead > > So it seems segmenting the registers is done to sort of control the > hardware versioning. > > I think it's better to use the compatible string to indicate different > versions of the hardware and then have just have one big > regs to cover all registers. The problem here is that the register ranges are not contiguous and the holes in between are used by other devices, so I can't use a single range. > > > +Valid gpio sub-nodes name are: > > + - "banks" for the standard banks > > + - "ao-bank" for the AO bank which belong to the special always-on > > + power domain > > I think it's unnecessary to split up banks, the compatible property > should be enough to know how many banks this controller has > and where they are located in relation to the base offset. I wanted to avoid a reg property with a list of 7 ranges. Anyway, I agree that the split seems a bit arbitrary; I'll remove it. > > +Required properties for configuration nodes: > > + - pins: the name of a pin group. The list of all available groups can > > + be found in driver sources. > > + - function: the name of a function to activate for the specified set > > + of groups. The list of all available functions can be found in > > + driver sources. > > This is interesting. I have established that for controllers mapping > functions to groups we use > "function" and "groups". > > So for per-pin configuration, "function" and "pins" would be > apropriate. I will use "groups" instead of "pins" for the pinmux configuration. Thanks! Beniamino
On Sun, Oct 26, 2014 at 7:25 PM, Beniamino Galvani <b.galvani@gmail.com> wrote: > On Fri, Oct 24, 2014 at 01:53:28PM +0200, Linus Walleij wrote: >> >> I think it's better to use the compatible string to indicate different >> versions of the hardware and then have just have one big >> regs to cover all registers. > > The problem here is that the register ranges are not contiguous and > the holes in between are used by other devices, so I can't use a > single range. OK I get it. >> So for per-pin configuration, "function" and "pins" would be >> apropriate. > > I will use "groups" instead of "pins" for the pinmux configuration. Excellent! Yours, Linus Walleij
diff --git a/Documentation/devicetree/bindings/pinctrl/meson,pinctrl.txt b/Documentation/devicetree/bindings/pinctrl/meson,pinctrl.txt new file mode 100644 index 0000000..dd573d9 --- /dev/null +++ b/Documentation/devicetree/bindings/pinctrl/meson,pinctrl.txt @@ -0,0 +1,80 @@ +* Amlogic Meson pinmux controller + +Pins are organized in banks; all banks except AO are controlled by the +same set of registers, while the AO bank uses a dedicated register +range. The device tree uses sub-nodes to represent set of banks which +share the same address space. + +Required properties for the root node: + - compatible: "amlogic,meson8-pinctrl" + - reg: address and size of the common registers controlling gpio irq + functionality + +Required properties for gpio sub-nodes: + - reg: should contain address and size for mux, pull-enable, pull and + gpio register sets + - reg-names: an array of strings describing the "reg" entries. Must + contain "mux", "pull" and "gpio". "pull-enable" is optional and + when it is missing the "pull" registers are used instead + - gpio-controller: identifies the node as a gpio controller + - #gpio-cells: must be 2 + +Valid gpio sub-nodes name are: + - "banks" for the standard banks + - "ao-bank" for the AO bank which belong to the special always-on + power domain + +Required properties for configuration nodes: + - pins: the name of a pin group. The list of all available groups can + be found in driver sources. + - function: the name of a function to activate for the specified set + of groups. The list of all available functions can be found in + driver sources. + +Example: + + pinctrl: pinctrl@c1109880 { + compatible = "amlogic,meson8-pinctrl"; + reg = <0xc1109880 0x10>; + #address-cells = <1>; + #size-cells = <1>; + ranges; + + gpio: banks@c11080b0 { + reg = <0xc11080b0 0x28>, + <0xc11080e4 0x18>, + <0xc1108120 0x18>, + <0xc1108030 0x30>; + reg-names = "mux", "pull-enable", "pull", "gpio"; + gpio-controller; + #gpio-cells = <2>; + }; + + gpio_ao: ao-bank@c1108030 { + reg = <0xc8100014 0x4>, + <0xc810002c 0x4>, + <0xc8100024 0x8>; + reg-names = "mux", "pull", "gpio"; + gpio-controller; + #gpio-cells = <2>; + }; + + nand { + nand { + pins = "nand_io", "nand_io_ce0", "nand_io_ce1", + "nand_io_rb0", "nand_ale", "nand_cle", + "nand_wen_clk", "nand_ren_clk", "nand_dqs", + "nand_ce2", "nand_ce3"; + function = "nand"; + }; + }; + + uart_ao_a: uart_ao_a { + uart_ao_a { + pins = "uart_tx_ao_a", "uart_rx_ao_a"; + "uart_cts_ao_a", "uart_rts_ao_a"; + function = "uart_ao"; + }; + }; + }; +
Add device tree bindings documentation for Amlogic Meson pinmux and GPIO controller. Signed-off-by: Beniamino Galvani <b.galvani@gmail.com> --- .../devicetree/bindings/pinctrl/meson,pinctrl.txt | 80 ++++++++++++++++++++++ 1 file changed, 80 insertions(+) create mode 100644 Documentation/devicetree/bindings/pinctrl/meson,pinctrl.txt