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diff --git a/Documentation/devicetree/bindings/pinctrl/atmel,at91-pinctrl.txt b/Documentation/devicetree/bindings/pinctrl/atmel,at91-pinctrl.txt new file mode 100644 index 000000000..e8abbdad7 --- /dev/null +++ b/Documentation/devicetree/bindings/pinctrl/atmel,at91-pinctrl.txt @@ -0,0 +1,176 @@ +* Atmel AT91 Pinmux Controller + +The AT91 Pinmux Controller, enables the IC +to share one PAD to several functional blocks. The sharing is done by +multiplexing the PAD input/output signals. For each PAD there are up to +8 muxing options (called periph modes). Since different modules require +different PAD settings (like pull up, keeper, etc) the controller controls +also the PAD settings parameters. + +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". + +Atmel AT91 pin configuration node is a node of a group of pins which can be +used for a specific device or function. This node represents both mux and config +of the pins in that group. The 'pins' selects the function mode(also named pin +mode) this pin can work on and the 'config' configures various pad settings +such as pull-up, multi drive, etc. + +Required properties for iomux controller: +- compatible: "atmel,at91rm9200-pinctrl" or "atmel,at91sam9x5-pinctrl" + or "atmel,sama5d3-pinctrl" or "microchip,sam9x60-pinctrl" +- atmel,mux-mask: array of mask (periph per bank) to describe if a pin can be + configured in this periph mode. All the periph and bank need to be describe. + +How to create such array: + +Each column will represent the possible peripheral of the pinctrl +Each line will represent a pio bank + +Take an example on the 9260 +Peripheral: 2 ( A and B) +Bank: 3 (A, B and C) +=> + + /* A B */ + 0xffffffff 0xffc00c3b /* pioA */ + 0xffffffff 0x7fff3ccf /* pioB */ + 0xffffffff 0x007fffff /* pioC */ + +For each peripheral/bank we will describe in a u32 if a pin can be +configured in it by putting 1 to the pin bit (1 << pin) + +Let's take the pioA on peripheral B +From the datasheet Table 10-2. +Peripheral B +PA0 MCDB0 +PA1 MCCDB +PA2 +PA3 MCDB3 +PA4 MCDB2 +PA5 MCDB1 +PA6 +PA7 +PA8 +PA9 +PA10 ETX2 +PA11 ETX3 +PA12 +PA13 +PA14 +PA15 +PA16 +PA17 +PA18 +PA19 +PA20 +PA21 +PA22 ETXER +PA23 ETX2 +PA24 ETX3 +PA25 ERX2 +PA26 ERX3 +PA27 ERXCK +PA28 ECRS +PA29 ECOL +PA30 RXD4 +PA31 TXD4 + +=> 0xffc00c3b + +Required properties for pin configuration node: +- atmel,pins: 4 integers array, represents a group of pins mux and config + setting. The format is atmel,pins = <PIN_BANK PIN_BANK_NUM PERIPH CONFIG>. + The PERIPH 0 means gpio, PERIPH 1 is periph A, PERIPH 2 is periph B... + PIN_BANK 0 is pioA, PIN_BANK 1 is pioB... + +Bits used for CONFIG: +PULL_UP (1 << 0): indicate this pin needs a pull up. +MULTIDRIVE (1 << 1): indicate this pin needs to be configured as multi-drive. + Multi-drive is equivalent to open-drain type output. +DEGLITCH (1 << 2): indicate this pin needs deglitch. +PULL_DOWN (1 << 3): indicate this pin needs a pull down. +DIS_SCHMIT (1 << 4): indicate this pin needs to the disable schmitt trigger. +DRIVE_STRENGTH (3 << 5): indicate the drive strength of the pin using the + following values: + 00 - No change (reset state value kept) + 01 - Low + 10 - Medium + 11 - High +OUTPUT (1 << 7): indicate this pin need to be configured as an output. +OUTPUT_VAL (1 << 8): output val (1 = high, 0 = low) +SLEWRATE (1 << 9): slew rate of the pin: 0 = disable, 1 = enable +DEBOUNCE (1 << 16): indicate this pin needs debounce. +DEBOUNCE_VAL (0x3fff << 17): debounce value. + +NOTE: +Some requirements for using atmel,at91rm9200-pinctrl binding: +1. We have pin function node defined under at91 controller node to represent + what pinmux functions this SoC supports. +2. The driver can use the function node's name and pin configuration node's + name describe the pin function and group hierarchy. + For example, Linux at91 pinctrl driver takes the function node's name + as the function name and pin configuration node's name as group name to + create the map table. +3. Each pin configuration node should have a phandle, devices can set pins + configurations by referring to the phandle of that pin configuration node. +4. The gpio controller must be describe in the pinctrl simple-bus. + +For each bank the required properties are: +- compatible: "atmel,at91sam9x5-gpio" or "atmel,at91rm9200-gpio" or + "microchip,sam9x60-gpio" +- reg: physical base address and length of the controller's registers +- interrupts: interrupt outputs from the controller +- interrupt-controller: marks the device node as an interrupt controller +- #interrupt-cells: should be 2; refer to ../interrupt-controller/interrupts.txt + for more details. +- gpio-controller +- #gpio-cells: should be 2; the first cell is the GPIO number and the second + cell specifies GPIO flags as defined in <dt-bindings/gpio/gpio.h>. +- clocks: bank clock + +Examples: + +pinctrl@fffff400 { + #address-cells = <1>; + #size-cells = <1>; + ranges; + compatible = "atmel,at91rm9200-pinctrl", "simple-bus"; + reg = <0xfffff400 0x600>; + + pioA: gpio@fffff400 { + compatible = "atmel,at91sam9x5-gpio"; + reg = <0xfffff400 0x200>; + interrupts = <2 IRQ_TYPE_LEVEL_HIGH 1>; + #gpio-cells = <2>; + gpio-controller; + interrupt-controller; + #interrupt-cells = <2>; + clocks = <&pmc PMC_TYPE_PERIPHERAL 2>; + }; + + atmel,mux-mask = < + /* A B */ + 0xffffffff 0xffc00c3b /* pioA */ + 0xffffffff 0x7fff3ccf /* pioB */ + 0xffffffff 0x007fffff /* pioC */ + >; + + /* shared pinctrl settings */ + dbgu { + pinctrl_dbgu: dbgu-0 { + atmel,pins = + <1 14 0x1 0x0 /* PB14 periph A */ + 1 15 0x1 0x1>; /* PB15 periph A with pullup */ + }; + }; +}; + +dbgu: serial@fffff200 { + compatible = "atmel,at91sam9260-usart"; + reg = <0xfffff200 0x200>; + interrupts = <1 4 7>; + pinctrl-names = "default"; + pinctrl-0 = <&pinctrl_dbgu>; +}; |