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authorArnd Bergmann <arnd@arndb.de>2012-11-26 15:57:58 +0400
committerArnd Bergmann <arnd@arndb.de>2012-11-26 15:57:58 +0400
commiteabc5fa51c1fae4b66cf883e3a3c2b3ca794494c (patch)
tree7e17333920f4ab9986f3f40e881b4bc890a91724 /Documentation/devicetree
parent9489e9dcae718d5fde988e4a684a0f55b5f94d17 (diff)
parentdf1590d9ae5e37e07e7cf91107e4c2c946ce8bf4 (diff)
downloadlinux-eabc5fa51c1fae4b66cf883e3a3c2b3ca794494c.tar.xz
Merge branch 'spear-for-3.8' of git://git.linaro.org/people/vireshk/linux into next/dt2
From Viresh Kumar <viresh.kumar@linaro.org>: These are DT updates for SPEAr SoCs. There aren't any fixes that we want to get into 3.7-rc* and we are happy with 3.8. Some of the dtbs which use gpiopinctrl have dependency on Linus's pinctrl tree, where an earlier update for adding gpiopinctrl node is present. * 'spear-for-3.8' of git://git.linaro.org/people/vireshk/linux: ARM: SPEAr3xx: Shirq: Move shirq controller out of plat/ ARM: SPEAr320: DT: Add SPEAr 320 HMI board support ARM: SPEAr3xx: DT: add shirq node for interrupt multiplexor ARM: SPEAr3xx: shirq: simplify and move the shared irq multiplexor to DT ARM: SPEAr1310: Fix AUXDATA for compact flash controller ARM: SPEAr13xx: Remove fields not required for ssp controller ARM: SPEAr1310: Move 1310 specific misc register into machine specific files ARM: SPEAr: DT: Update device nodes ARM: SPEAr: DT: add uart state to fix warning ARM: SPEAr: DT: Modify DT bindings for STMMAC ARM: SPEAr: DT: Fix existing DT support ARM: SPEAr: DT: Update partition info for MTD devices ARM: SPEAr: DT: Update pinctrl list ARM: SPEAr13xx: DT: Add spics gpio controller nodes Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'Documentation/devicetree')
-rw-r--r--Documentation/devicetree/bindings/arm/spear/shirq.txt48
-rw-r--r--Documentation/devicetree/bindings/gpio/gpio.txt36
-rw-r--r--Documentation/devicetree/bindings/gpio/spear_spics.txt50
3 files changed, 134 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/arm/spear/shirq.txt b/Documentation/devicetree/bindings/arm/spear/shirq.txt
new file mode 100644
index 000000000000..13fbb8866bd6
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/spear/shirq.txt
@@ -0,0 +1,48 @@
+* SPEAr Shared IRQ layer (shirq)
+
+SPEAr3xx architecture includes shared/multiplexed irqs for certain set
+of devices. The multiplexor provides a single interrupt to parent
+interrupt controller (VIC) on behalf of a group of devices.
+
+There can be multiple groups available on SPEAr3xx variants but not
+exceeding 4. The number of devices in a group can differ, further they
+may share same set of status/mask registers spanning across different
+bit masks. Also in some cases the group may not have enable or other
+registers. This makes software little complex.
+
+A single node in the device tree is used to describe the shared
+interrupt multiplexor (one node for all groups). A group in the
+interrupt controller shares config/control registers with other groups.
+For example, a 32-bit interrupt enable/disable config register can
+accommodate upto 4 interrupt groups.
+
+Required properties:
+ - compatible: should be, either of
+ - "st,spear300-shirq"
+ - "st,spear310-shirq"
+ - "st,spear320-shirq"
+ - interrupt-controller: Identifies the node as an interrupt controller.
+ - #interrupt-cells: should be <1> which basically contains the offset
+ (starting from 0) of interrupts for all the groups.
+ - reg: Base address and size of shirq registers.
+ - interrupts: The list of interrupts generated by the groups which are
+ then connected to a parent interrupt controller. Each group is
+ associated with one of the interrupts, hence number of interrupts (to
+ parent) is equal to number of groups. The format of the interrupt
+ specifier depends in the interrupt parent controller.
+
+ Optional properties:
+ - interrupt-parent: pHandle of the parent interrupt controller, if not
+ inherited from the parent node.
+
+Example:
+
+The following is an example from the SPEAr320 SoC dtsi file.
+
+shirq: interrupt-controller@0xb3000000 {
+ compatible = "st,spear320-shirq";
+ reg = <0xb3000000 0x1000>;
+ interrupts = <28 29 30 1>;
+ #interrupt-cells = <1>;
+ interrupt-controller;
+};
diff --git a/Documentation/devicetree/bindings/gpio/gpio.txt b/Documentation/devicetree/bindings/gpio/gpio.txt
index 4e16ba4feab0..a33628759d36 100644
--- a/Documentation/devicetree/bindings/gpio/gpio.txt
+++ b/Documentation/devicetree/bindings/gpio/gpio.txt
@@ -75,4 +75,40 @@ Example of two SOC GPIO banks defined as gpio-controller nodes:
gpio-controller;
};
+2.1) gpio-controller and pinctrl subsystem
+------------------------------------------
+gpio-controller on a SOC might be tightly coupled with the pinctrl
+subsystem, in the sense that the pins can be used by other functions
+together with optional gpio feature.
+
+While the pin allocation is totally managed by the pin ctrl subsystem,
+gpio (under gpiolib) is still maintained by gpio drivers. It may happen
+that different pin ranges in a SoC is managed by different gpio drivers.
+
+This makes it logical to let gpio drivers announce their pin ranges to
+the pin ctrl subsystem and call 'pinctrl_request_gpio' in order to
+request the corresponding pin before any gpio usage.
+
+For this, the gpio controller can use a pinctrl phandle and pins to
+announce the pinrange to the pin ctrl subsystem. For example,
+
+ qe_pio_e: gpio-controller@1460 {
+ #gpio-cells = <2>;
+ compatible = "fsl,qe-pario-bank-e", "fsl,qe-pario-bank";
+ reg = <0x1460 0x18>;
+ gpio-controller;
+ gpio-ranges = <&pinctrl1 20 10>, <&pinctrl2 50 20>;
+
+ }
+
+where,
+ &pinctrl1 and &pinctrl2 is the phandle to the pinctrl DT node.
+
+ Next values specify the base pin and number of pins for the range
+ handled by 'qe_pio_e' gpio. In the given example from base pin 20 to
+ pin 29 under pinctrl1 and pin 50 to pin 69 under pinctrl2 is handled
+ by this gpio controller.
+
+The pinctrl node must have "#gpio-range-cells" property to show number of
+arguments to pass with phandle from gpio controllers node.
diff --git a/Documentation/devicetree/bindings/gpio/spear_spics.txt b/Documentation/devicetree/bindings/gpio/spear_spics.txt
new file mode 100644
index 000000000000..96c37eb15075
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/spear_spics.txt
@@ -0,0 +1,50 @@
+=== ST Microelectronics SPEAr SPI CS Driver ===
+
+SPEAr platform provides a provision to control chipselects of ARM PL022 Prime
+Cell spi controller through its system registers, which otherwise remains under
+PL022 control. If chipselect remain under PL022 control then they would be
+released as soon as transfer is over and TxFIFO becomes empty. This is not
+desired by some of the device protocols above spi which expect (multiple)
+transfers without releasing their chipselects.
+
+Chipselects can be controlled by software by turning them as GPIOs. SPEAr
+provides another interface through system registers through which software can
+directly control each PL022 chipselect. Hence, it is natural for SPEAr to export
+the control of this interface as gpio.
+
+Required properties:
+
+ * compatible: should be defined as "st,spear-spics-gpio"
+ * reg: mentioning address range of spics controller
+ * st-spics,peripcfg-reg: peripheral configuration register offset
+ * st-spics,sw-enable-bit: bit offset to enable sw control
+ * st-spics,cs-value-bit: bit offset to drive chipselect low or high
+ * st-spics,cs-enable-mask: chip select number bit mask
+ * st-spics,cs-enable-shift: chip select number program offset
+ * gpio-controller: Marks the device node as gpio controller
+ * #gpio-cells: should be 1 and will mention chip select number
+
+All the above bit offsets are within peripcfg register.
+
+Example:
+-------
+spics: spics@e0700000{
+ compatible = "st,spear-spics-gpio";
+ reg = <0xe0700000 0x1000>;
+ st-spics,peripcfg-reg = <0x3b0>;
+ st-spics,sw-enable-bit = <12>;
+ st-spics,cs-value-bit = <11>;
+ st-spics,cs-enable-mask = <3>;
+ st-spics,cs-enable-shift = <8>;
+ gpio-controller;
+ #gpio-cells = <2>;
+};
+
+
+spi0: spi@e0100000 {
+ status = "okay";
+ num-cs = <3>;
+ cs-gpios = <&gpio1 7 0>, <&spics 0>,
+ <&spics 1>;
+ ...
+}