diff options
| author | Simon Glass <sjg@chromium.org> | 2020-09-22 21:45:01 +0300 |
|---|---|---|
| committer | Bin Meng <bmeng.cn@gmail.com> | 2020-09-25 06:27:15 +0300 |
| commit | fd42f263cef9fd6bba9ded76a82d4ac66450e156 (patch) | |
| tree | 64bc139fe69c2d50a6200ccda1f1c521e45643b4 /doc | |
| parent | bddbaf5edf0e01817f2577295c3d682e4d5fed09 (diff) | |
| download | u-boot-fd42f263cef9fd6bba9ded76a82d4ac66450e156.tar.xz | |
i2c: Add a generic driver to generate ACPI info
Many I2C devices produce roughly the same ACPI data with just things like
the GPIO/interrupt information being different.
This can be handled by a generic driver along with some information in the
device tree.
Add a generic i2c driver for this purpose.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Heiko Schocher <hs@denx.de>
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/device-tree-bindings/i2c/generic-acpi.txt | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/doc/device-tree-bindings/i2c/generic-acpi.txt b/doc/device-tree-bindings/i2c/generic-acpi.txt new file mode 100644 index 0000000000..3510a71b57 --- /dev/null +++ b/doc/device-tree-bindings/i2c/generic-acpi.txt @@ -0,0 +1,42 @@ +I2C generic device +================== + +This is used only to generate ACPI tables for an I2C device. + +Required properties : + + - compatible : "i2c-chip"; + - reg : I2C chip address + - acpi,hid : HID name for the device + +Optional properies in addition to device.txt: + + - reset-gpios : GPIO used to assert reset to the device + - irq-gpios : GPIO used for interrupt (if Interrupt is not used) + - stop-gpios : GPIO used to stop the device + - interrupts-extended : Interrupt to use for the device + - reset-delay-ms : Delay after de-asserting reset, in ms + - reset-off-delay-ms : Delay after asserting reset (during power off) + - enable-delay-ms : Delay after asserting enable + - enable-off-delay-ms : Delay after de-asserting enable (during power off) + - stop-delay-ms : Delay after de-aserting stop + - stop-off-delay-ms : Delay after asserting stop (during power off) + - hid-descr-addr : HID register offset (for Human Interface Devices) + +Example +------- + + elan-touchscreen@10 { + compatible = "i2c-chip"; + reg = <0x10>; + acpi,hid = "ELAN0001"; + acpi,ddn = "ELAN Touchscreen"; + interrupts-extended = <&acpi_gpe GPIO_21_IRQ + IRQ_TYPE_EDGE_FALLING>; + linux,probed; + reset-gpios = <&gpio_n GPIO_36 GPIO_ACTIVE_HIGH>; + reset-delay-ms = <20>; + enable-gpios = <&gpio_n GPIO_152 GPIO_ACTIVE_HIGH>; + enable-delay-ms = <1>; + acpi,has-power-resource; + }; |