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linux-next/Documentation/devicetree/bindings/pinctrl/xlnx,zynq-pinctrl.txt
Helmut Buchsbaum 83a21727c3 pinctrl: zynq: configure SPI SSx pins separately
Since SCLK, MISO and MOSI are the only mandatory signals at Zynq's SPI
interfaces, SS0, SS1 and SS2 have to be configured separately as they may
be used as simple GPIO lines.

This, of course, has to be considered in the devicetree, so pin controller
configuration for e.g. an SPI0 using SS0 and SS1 only might look like the
following snippet (derived from the example of chapter "17.5.3
MIO/EMIO" Routing of Zynq-7000 TRM UG585). So MIO20 can now be used
as GPIO instead of being occupied by SPI0 SS2 function. Note the separate
pinmux function for the slave select signals:

pinctrl_spi0_default: spi0-default {
	mux_spi {
		function = "spi0";
		groups = "spi0_0_grp";
	};

	mux_ss {
		function = "spi0_ss";
		groups = "spi0_0_ss0_grp", "spi0_0_ss1_grp";
	}

	conf-output {
		pins = "MIO16", "MIO21";
		slew-rate = <0>;
		bias-disable;
		low-power-disable;
		io-standard = <1>;
	};

	conf-input {
		pins = "MIO17";
		slew-rate = <0>;
		bias-high-impedance;
		low-power-disable;
		io-standard = <1>;
	};

	conf-select {
		pins = "MIO18", "MIO19";
		slew-rate = <0>;
		bias-pull-up;
		low-power-disable;
		io-standard = <1>;
	};
};

pinctrl_gpio0_default {
	mux {
		function = "gpio0";
		groups = "gpio0_20_grp"
	};

	conf {
		pins = "MIO20";
		slew-rate = <0>;
		bias-pull-up;
		low-power-disable;
		io-standard = <1>;
	};
};

Signed-off-by: Helmut Buchsbaum <helmut.buchsbaum@gmail.com>
Acked-by: Sören Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-05-06 15:26:52 +02:00

106 lines
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Binding for Xilinx Zynq Pinctrl
Required properties:
- compatible: "xlnx,zynq-pinctrl"
- syscon: phandle to SLCR
- reg: Offset and length of pinctrl space in SLCR
Please refer to pinctrl-bindings.txt in this directory for details of the
common pinctrl bindings used by client devices, including the meaning of the
phrase "pin configuration node".
Zynq's pin configuration nodes act as a container for an arbitrary number of
subnodes. Each of these subnodes represents some desired configuration for a
pin, a group, or a list of pins or groups. This configuration can include the
mux function to select on those pin(s)/group(s), and various pin configuration
parameters, such as pull-up, slew rate, etc.
Each configuration node can consist of multiple nodes describing the pinmux and
pinconf options. Those nodes can be pinmux nodes or pinconf nodes.
The name of each subnode is not important; all subnodes should be enumerated
and processed purely based on their content.
Required properties for pinmux nodes are:
- groups: A list of pinmux groups.
- function: The name of a pinmux function to activate for the specified set
of groups.
Required properties for configuration nodes:
One of:
- pins: a list of pin names
- groups: A list of pinmux groups.
The following generic properties as defined in pinctrl-bindings.txt are valid
to specify in a pinmux subnode:
groups, function
The following generic properties as defined in pinctrl-bindings.txt are valid
to specify in a pinconf subnode:
groups, pins, bias-disable, bias-high-impedance, bias-pull-up, slew-rate,
low-power-disable, low-power-enable
Valid arguments for 'slew-rate' are '0' and '1' to select between slow and fast
respectively.
Valid values for groups are:
ethernet0_0_grp, ethernet1_0_grp, mdio0_0_grp, mdio1_0_grp,
qspi0_0_grp, qspi1_0_grp, qspi_fbclk, qspi_cs1_grp, spi0_0_grp - spi0_2_grp,
spi0_X_ssY (X=0..2, Y=0..2), spi1_0_grp - spi1_3_grp,
spi1_X_ssY (X=0..3, Y=0..2), sdio0_0_grp - sdio0_2_grp,
sdio1_0_grp - sdio1_3_grp, sdio0_emio_wp, sdio0_emio_cd, sdio1_emio_wp,
sdio1_emio_cd, smc0_nor, smc0_nor_cs1_grp, smc0_nor_addr25_grp, smc0_nand,
can0_0_grp - can0_10_grp, can1_0_grp - can1_11_grp, uart0_0_grp - uart0_10_grp,
uart1_0_grp - uart1_11_grp, i2c0_0_grp - i2c0_10_grp, i2c1_0_grp - i2c1_10_grp,
ttc0_0_grp - ttc0_2_grp, ttc1_0_grp - ttc1_2_grp, swdt0_0_grp - swdt0_4_grp,
gpio0_0_grp - gpio0_53_grp, usb0_0_grp, usb1_0_grp
Valid values for pins are:
MIO0 - MIO53
Valid values for function are:
ethernet0, ethernet1, mdio0, mdio1, qspi0, qspi1, qspi_fbclk, qspi_cs1,
spi0, spi0_ss, spi1, spi1_ss, sdio0, sdio0_pc, sdio0_cd, sdio0_wp,
sdio1, sdio1_pc, sdio1_cd, sdio1_wp,
smc0_nor, smc0_nor_cs1, smc0_nor_addr25, smc0_nand, can0, can1, uart0, uart1,
i2c0, i2c1, ttc0, ttc1, swdt0, gpio0, usb0, usb1
The following driver-specific properties as defined here are valid to specify in
a pin configuration subnode:
- io-standard: Configure the pin to use the selected IO standard according to
this mapping:
1: LVCMOS18
2: LVCMOS25
3: LVCMOS33
4: HSTL
Example:
pinctrl0: pinctrl@700 {
compatible = "xlnx,pinctrl-zynq";
reg = <0x700 0x200>;
syscon = <&slcr>;
pinctrl_uart1_default: uart1-default {
mux {
groups = "uart1_10_grp";
function = "uart1";
};
conf {
groups = "uart1_10_grp";
slew-rate = <0>;
io-standard = <1>;
};
conf-rx {
pins = "MIO49";
bias-high-impedance;
};
conf-tx {
pins = "MIO48";
bias-disable;
};
};
};