- Devices behind real busses where there is a connector resource
are represented as struct spi_device or struct i2c_device. Note
that standard UARTs are not busses so there is no struct uart_device,
- although some of them may be represented by sturct serdev_device.
+ although some of them may be represented by struct serdev_device.
As both ACPI and Device Tree represent a tree of devices (and their
resources) this implementation follows the Device Tree way as much as
}
...
-The SPI device drivers only need to add ACPI IDs in a similar way than with
+The SPI device drivers only need to add ACPI IDs in a similar way to
the platform device drivers. Below is an example where we add ACPI support
to at25 SPI eeprom driver (this is meant for the above ACPI snippet)::
specifies the path to the controller. In order to use these GPIOs in Linux
we need to translate them to the corresponding Linux GPIO descriptors.
-There is a standard GPIO API for that and is documented in
+There is a standard GPIO API for that and it is documented in
Documentation/admin-guide/gpio/.
In the above example we can get the corresponding two GPIO descriptors with
PCI hierarchy representation
============================
-Sometimes could be useful to enumerate a PCI device, knowing its position on the
-PCI bus.
+Sometimes it could be useful to enumerate a PCI device, knowing its position on
+the PCI bus.
For example, some systems use PCI devices soldered directly on the mother board,
in a fixed position (ethernet, Wi-Fi, serial ports, etc.). In this conditions it
the chipset root port to the final device, through all the intermediate
bridges/switches of the board.
-For example, let us assume to have a system with a PCIe serial port, an
+For example, let's assume we have a system with a PCIe serial port, an
Exar XR17V3521, soldered on the main board. This UART chip also includes
16 GPIOs and we want to add the property ``gpio-line-names`` [1] to these pins.
In this case, the ``lspci`` output for this component is::
Bus: 0 - Device: 14 - Function: 1
-To find this information is necessary disassemble the BIOS ACPI tables, in
-particular the DSDT (see also [2])::
+To find this information, it is necessary to disassemble the BIOS ACPI tables,
+in particular the DSDT (see also [2])::
mkdir ~/tables/
cd ~/tables/