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31d610f196
Support gpio devicetree subnodes to allow a more detailed DT hardware description. Signed-off-by: Markus Pargmann <mpa@pengutronix.de> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
122 lines
3.1 KiB
Plaintext
122 lines
3.1 KiB
Plaintext
* Freescale IMX27 IOMUX Controller
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Required properties:
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- compatible: "fsl,imx27-iomuxc"
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The iomuxc driver node should define subnodes containing of pinctrl configuration subnodes.
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Required properties for pin configuration node:
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- fsl,pins: three integers array, represents a group of pins mux and config
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setting. The format is fsl,pins = <PIN MUX_ID CONFIG>.
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PIN is an integer between 0 and 0xbf. imx27 has 6 ports with 32 configurable
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configurable pins each. PIN is PORT * 32 + PORT_PIN, PORT_PIN is the pin
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number on the specific port (between 0 and 31).
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MUX_ID is
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function + (direction << 2) + (gpio_oconf << 4) + (gpio_iconfa << 8) + (gpio_iconfb << 10)
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function value is used to select the pin function.
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Possible values:
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0 - Primary function
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1 - Alternate function
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2 - GPIO
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Registers: GIUS (GPIO In Use), GPR (General Purpose Register)
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direction defines the data direction of the pin.
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Possible values:
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0 - Input
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1 - Output
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Register: DDIR
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gpio_oconf configures the gpio submodule output signal. This does not
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have any effect unless GPIO function is selected. A/B/C_IN are output
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signals of function blocks A,B and C. Specific function blocks are
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described in the reference manual.
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Possible values:
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0 - A_IN
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1 - B_IN
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2 - C_IN
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3 - Data Register
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Registers: OCR1, OCR2
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gpio_iconfa/b configures the gpio submodule input to functionblocks A and
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B. GPIO function should be selected if this is configured.
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Possible values:
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0 - GPIO_IN
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1 - Interrupt Status Register
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2 - Pulldown
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3 - Pullup
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Registers ICONFA1, ICONFA2, ICONFB1 and ICONFB2
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CONFIG can be 0 or 1, meaning Pullup disable/enable.
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The iomux controller has gpio child nodes which are embedded in the iomux
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control registers. They have to be defined as child nodes of the iomux device
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node. If gpio subnodes are defined "#address-cells", "#size-cells" and "ranges"
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properties for the iomux device node are required.
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Example:
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iomuxc: iomuxc@10015000 {
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compatible = "fsl,imx27-iomuxc";
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reg = <0x10015000 0x600>;
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#address-cells = <1>;
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#size-cells = <1>;
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ranges;
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gpio1: gpio@10015000 {
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...
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};
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...
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uart {
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pinctrl_uart1: uart-1 {
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fsl,pins = <
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0x8c 0x004 0x0 /* UART1_TXD__UART1_TXD */
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0x8d 0x000 0x0 /* UART1_RXD__UART1_RXD */
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0x8e 0x004 0x0 /* UART1_CTS__UART1_CTS */
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0x8f 0x000 0x0 /* UART1_RTS__UART1_RTS */
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>;
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};
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...
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};
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};
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For convenience there are macros defined in imx27-pinfunc.h which provide PIN
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and MUX_ID. They are structured as MX27_PAD_<Pad name>__<Signal name>. The names
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are defined in the i.MX27 reference manual.
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The above example using macros:
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iomuxc: iomuxc@10015000 {
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compatible = "fsl,imx27-iomuxc";
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reg = <0x10015000 0x600>;
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#address-cells = <1>;
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#size-cells = <1>;
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ranges;
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gpio1: gpio@10015000 {
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...
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};
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...
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uart {
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pinctrl_uart1: uart-1 {
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fsl,pins = <
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MX27_PAD_UART1_TXD__UART1_TXD 0x0
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MX27_PAD_UART1_RXD__UART1_RXD 0x0
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MX27_PAD_UART1_CTS__UART1_CTS 0x0
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MX27_PAD_UART1_RTS__UART1_RTS 0x0
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>;
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};
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...
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};
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};
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