diff options
Diffstat (limited to 'dts/Bindings/gpio/nvidia,tegra186-gpio.txt')
| -rw-r--r-- | dts/Bindings/gpio/nvidia,tegra186-gpio.txt | 165 |
1 files changed, 0 insertions, 165 deletions
diff --git a/dts/Bindings/gpio/nvidia,tegra186-gpio.txt b/dts/Bindings/gpio/nvidia,tegra186-gpio.txt deleted file mode 100644 index adff16c71d..0000000000 --- a/dts/Bindings/gpio/nvidia,tegra186-gpio.txt +++ /dev/null @@ -1,165 +0,0 @@ -NVIDIA Tegra186 GPIO controllers - -Tegra186 contains two GPIO controllers; a main controller and an "AON" -controller. This binding document applies to both controllers. The register -layouts for the controllers share many similarities, but also some significant -differences. Hence, this document describes closely related but different -bindings and compatible values. - -The Tegra186 GPIO controller allows software to set the IO direction of, and -read/write the value of, numerous GPIO signals. Routing of GPIO signals to -package balls is under the control of a separate pin controller HW block. Two -major sets of registers exist: - -a) Security registers, which allow configuration of allowed access to the GPIO -register set. These registers exist in a single contiguous block of physical -address space. The size of this block, and the security features available, -varies between the different GPIO controllers. - -Access to this set of registers is not necessary in all circumstances. Code -that wishes to configure access to the GPIO registers needs access to these -registers to do so. Code which simply wishes to read or write GPIO data does not -need access to these registers. - -b) GPIO registers, which allow manipulation of the GPIO signals. In some GPIO -controllers, these registers are exposed via multiple "physical aliases" in -address space, each of which access the same underlying state. See the hardware -documentation for rationale. Any particular GPIO client is expected to access -just one of these physical aliases. - -Tegra HW documentation describes a unified naming convention for all GPIOs -implemented by the SoC. Each GPIO is assigned to a port, and a port may control -a number of GPIOs. Thus, each GPIO is named according to an alphabetical port -name and an integer GPIO name within the port. For example, GPIO_PA0, GPIO_PN6, -or GPIO_PCC3. - -The number of ports implemented by each GPIO controller varies. The number of -implemented GPIOs within each port varies. GPIO registers within a controller -are grouped and laid out according to the port they affect. - -The mapping from port name to the GPIO controller that implements that port, and -the mapping from port name to register offset within a controller, are both -extremely non-linear. The header file <dt-bindings/gpio/tegra186-gpio.h> -describes the port-level mapping. In that file, the naming convention for ports -matches the HW documentation. The values chosen for the names are alphabetically -sorted within a particular controller. Drivers need to map between the DT GPIO -IDs and HW register offsets using a lookup table. - -Each GPIO controller can generate a number of interrupt signals. Each signal -represents the aggregate status for all GPIOs within a set of ports. Thus, the -number of interrupt signals generated by a controller varies as a rough function -of the number of ports it implements. Note that the HW documentation refers to -both the overall controller HW module and the sets-of-ports as "controllers". - -Each GPIO controller in fact generates multiple interrupts signals for each set -of ports. Each GPIO may be configured to feed into a specific one of the -interrupt signals generated by a set-of-ports. The intent is for each generated -signal to be routed to a different CPU, thus allowing different CPUs to each -handle subsets of the interrupts within a port. The status of each of these -per-port-set signals is reported via a separate register. Thus, a driver needs -to know which status register to observe. This binding currently defines no -configuration mechanism for this. By default, drivers should use register -GPIO_${port}_INTERRUPT_STATUS_G1_0. Future revisions to the binding could -define a property to configure this. - -Required properties: -- compatible - Array of strings. - One of: - - "nvidia,tegra186-gpio". - - "nvidia,tegra186-gpio-aon". - - "nvidia,tegra194-gpio". - - "nvidia,tegra194-gpio-aon". -- reg-names - Array of strings. - Contains a list of names for the register spaces described by the reg - property. May contain the following entries, in any order: - - "gpio": Mandatory. GPIO control registers. This may cover either: - a) The single physical alias that this OS should use. - b) All physical aliases that exist in the controller. This is - appropriate when the OS is responsible for managing assignment of - the physical aliases. - - "security": Optional. Security configuration registers. - Users of this binding MUST look up entries in the reg property by name, - using this reg-names property to do so. -- reg - Array of (physical base address, length) tuples. - Must contain one entry per entry in the reg-names property, in a matching - order. -- interrupts - Array of interrupt specifiers. - The interrupt outputs from the HW block, one per set of ports, in the - order the HW manual describes them. The number of entries required varies - depending on compatible value: - - "nvidia,tegra186-gpio": 6 entries. - - "nvidia,tegra186-gpio-aon": 1 entry. - - "nvidia,tegra194-gpio": 6 entries. - - "nvidia,tegra194-gpio-aon": 1 entry. -- gpio-controller - Boolean. - Marks the device node as a GPIO controller/provider. -- #gpio-cells - Single-cell integer. - Must be <2>. - Indicates how many cells are used in a consumer's GPIO specifier. - In the specifier: - - The first cell is the pin number. - See <dt-bindings/gpio/tegra186-gpio.h>. - - The second cell contains flags: - - Bit 0 specifies polarity - - 0: Active-high (normal). - - 1: Active-low (inverted). -- interrupt-controller - Boolean. - Marks the device node as an interrupt controller/provider. -- #interrupt-cells - Single-cell integer. - Must be <2>. - Indicates how many cells are used in a consumer's interrupt specifier. - In the specifier: - - The first cell is the GPIO number. - See <dt-bindings/gpio/tegra186-gpio.h>. - - The second cell is contains flags: - - Bits [3:0] indicate trigger type and level: - - 1: Low-to-high edge triggered. - - 2: High-to-low edge triggered. - - 4: Active high level-sensitive. - - 8: Active low level-sensitive. - Valid combinations are 1, 2, 3, 4, 8. - -Example: - -#include <dt-bindings/interrupt-controller/irq.h> - -gpio@2200000 { - compatible = "nvidia,tegra186-gpio"; - reg-names = "security", "gpio"; - reg = - <0x0 0x2200000 0x0 0x10000>, - <0x0 0x2210000 0x0 0x10000>; - interrupts = - <0 47 IRQ_TYPE_LEVEL_HIGH>, - <0 50 IRQ_TYPE_LEVEL_HIGH>, - <0 53 IRQ_TYPE_LEVEL_HIGH>, - <0 56 IRQ_TYPE_LEVEL_HIGH>, - <0 59 IRQ_TYPE_LEVEL_HIGH>, - <0 180 IRQ_TYPE_LEVEL_HIGH>; - gpio-controller; - #gpio-cells = <2>; - interrupt-controller; - #interrupt-cells = <2>; -}; - -gpio@c2f0000 { - compatible = "nvidia,tegra186-gpio-aon"; - reg-names = "security", "gpio"; - reg = - <0x0 0xc2f0000 0x0 0x1000>, - <0x0 0xc2f1000 0x0 0x1000>; - interrupts = - <0 60 IRQ_TYPE_LEVEL_HIGH>; - gpio-controller; - #gpio-cells = <2>; - interrupt-controller; - #interrupt-cells = <2>; -}; |