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u-boot/doc/device-tree-bindings/pinctrl/canaan,k210-fpioa.txt
Damien Le Moal fd426b3106 k210: use the board vendor name rather than the marketing name
"kendryte" is the marketing name for the K210 RISC-V SoC produced by
Canaan Inc. Rather than "kendryte,k210", use the usual "canaan,k210"
vendor,SoC compatibility string format in the device tree files and
use the SoC name for file names.
With these changes, the device tree files are more in sync with the
Linux kernel DTS and drivers, making uboot device tree usable by the
kernel.

Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
Reviewed-by: Leo Yu-Chi Liang <ycliang@andestech.com>
2022-03-15 17:43:11 +08:00

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Kendryte K210 FPIOA
This binding describes the Fully-Programmable Input/Output Array (FPIOA) found
in Kendryte K210 SoCs. Any of the 256 functions can be mapped to any of the 48
pins.
Required properties:
- compatible: should be "canaan,k210-fpioa"
- reg: address and length of the FPIOA registers
- canaan,sysctl: phandle to the "sysctl" register map node
- canaan,k210-power-offset: offset in the register map of the power bank control
register (in bytes)
Configuration nodes
Pin configuration nodes are documented in pinctrl-bindings.txt
Required properties for pin-configuration nodes or sub-nodes are:
- groups: list of power groups to which the configuration applies. Valid groups
are:
A0, A1, A2, B3, B4, B5, C6, C7
(either this or "pinmux" must be specified)
- pinmux: integer array representing pin multiplexing configuration. In addition
to the 256 standard functions, each pin can also output the direction
indicator (DO) of any function. This signal is high whenever the function
would normally drive the output. Helper macros to ease assembling the "pinmux"
arguments from the pin and function are provided by the FPIOA header file at:
<dt-bindings/pinctrl/k210-pinctrl.h>
Integer values in the "pinmux" argument list are assembled as:
((PIN << 16) | (DO << 8) | (FUNC))
Valid values for PIN are numbers 0 through 47.
Valid values for DO are 0 or 1.
Valid values for FUNC are numbers 0 through 255. For a complete list of
acceptable functions, consult the FPIOA header file.
(either this or "groups" must be specified)
Optional properties for "pinmux" nodes are:
bias-disable, bias-pull-down, bias-pull-up, drive-strength,
drive-strength-ua, input-enable, input-disable, input-schmitt-enable,
input-schmitt-disable, output-low, output-high, output-enable,
output-disable, slew-rate, output-polarity-invert, input-polarity-invert
Optional properties for "groups" nodes are:
power-source
Notes on specific properties include:
- bias-pull-up, -down, and -pin-default: The pull strength cannot be configured.
- drive-strength: There are 8 drive strength settings between 11 and 50 mA.
- input- and output-polarity-invert: Invert the polarity of either the input or
the output, respectively.
- power-source: Controls the output voltage of a bank of pins. Either
K210_PC_POWER_1V8 or K210_PC_POWER_3V3 may be specified.
- slew-rate: Specifying this property reduces the slew rate.
Example:
fpioa: pinmux@502B0000 {
compatible = "canaan,k210-fpioa";
reg = <0x502B0000 0x100>;
canaan,k210-sysctl = <&sysctl>;
canaan,k210-power-offset = <K210_SYSCTL_POWER_SEL>;
/* JTAG running at 3.3V and driven at 11 mA */
fpioa_jtag: jtag {
voltage {
group = "A0";
power-source = <K210_PC_POWER_3V3>;
};
jtag {
pinmux = <K210_FPIOA(0, K210_PCF_JTAG_TCK)>,
<K210_FPIOA(1, K210_PCF_JTAG_TDI)>,
<K210_FPIOA(2, K210_PCF_JTAG_TMS)>,
<K210_FPIOA(3, K210_PCF_JTAG_TDO)>;
drive-strength = <11>;
}
};
/* I2C configured for use with a TCA9800 level shifter */
fpioa_i2c: i2c {
i2c {
pinmux = <K210_FPIOA(6, K210_PCF_I2C0_SCLK)>,
<K210_FPIOA(7, K210_PCF_I2C0_SDA)>;
};
direction {
pinmux = <K210_FPIOA_DO(8, K210_PCF_I2C0_SDA)>;
output-polarity-invert;
};
};
/* UART with an active-high TX status LED */
fpioa_uart1: uart1 {
uart {
pinmux = <K210_FPIOA(9, K210_PCF_UART1_TX)>,
<K210_FPIOA(10, K210_PCF_UART1_RX)>;
};
status {
pinmux = <K210_FPIOA_DO(11, K210_PCF_UART1_TX)>;
};
};
};