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Subject[PATCH 00/19] Dynamically load/remove serdev devices via sysfs*
Date
There are some situations where it is interesting to load/remove serdev
devices dynamically, like during board bring-up or when we are
developing a new driver or for devices that are neither described via
ACPI or device tree.

This implementation allows the creation of serdev devices via sysfs,
in a similar way as the i2c bus allows sysfs instantiation [1].

It also opens the door to create platform drivers for specific
platforms, such us notebooks or industrial computers, when their serial
devices are not described via DT or ACPI.

This patchset also supports automatic module load via udev/modprobe,
simplifying its use by the final user.

Currently, serdev does not manage ports that do not have a serdev device
defined at boot time. This implementation adds a new serdev module,
ttydev, that provides the same functionality of tty (it calls the
original one), but can be unloaded.

TL/DR:

When we want to create a new device, we just run:
root@qt5022:~# echo ttydev > /sys/bus/serial/devices/serial0/new_device

This will create a new device:
root@qt5022:~# ls /sys/bus/serial/devices/serial0-0/
driver modalias power subsystem tty uevent

And load the required driver to use it:
root@qt5022:~# lsmod | grep serdev_ttydev
serdev_ttydev 16384 0

The device can be removed:
root@qt5022:~#
echo serial0-0 > /sys/bus/serial/devices/serial0/delete_device

And now we can connect a new device:
root@qt5022:~# echo hci-ti > /sys/bus/serial/devices/serial0/new_device


[1] https://www.kernel.org/doc/Documentation/i2c/instantiating-devices

Ricardo Ribalda Delgado (19):
serdev: Add id_table to serdev_device_driver
Bluetooth: hci_bcm: Add serdev_id_table
Bluetooth: hci_ll: Add serdev_id_table
Bluetooth: hci_nokia: Add serdev_id_table
serdev: Introduce modalias field
serdev: Support bus matching with modalias field
serdev: Allows dynamic creation of devices via sysfs
serdev: Provide modalias attribute for modalias devices
serdev: Provide modalias uevent for modalias devices
file2alias: Support for serdev devices
Bluetooth: hci_bcm: MODULE_DEVICE_TABLE(serdev)
Bluetooth: hci_ll: MODULE_DEVICE_TABLE(serdev)
Bluetooth: hci_nokia: MODULE_DEVICE_TABLE(serdev)
mfd: rave-sp: MODULE_DEVICE_TABLE(serdev)
net: qualcomm: MODULE_DEVICE_TABLE(serdev)
serdev: ttyport: Move serport structure to its own header
serdev: Mark controllers compatible with ttyport
serdev: ttydev: Serdev driver that creates an standard TTY port
serdev: Instantiate a ttydev serdev if acpi and of fails

drivers/bluetooth/hci_bcm.c | 8 ++
drivers/bluetooth/hci_ll.c | 19 ++++
drivers/bluetooth/hci_nokia.c | 8 ++
drivers/mfd/rave-sp.c | 7 ++
drivers/net/ethernet/qualcomm/qca_uart.c | 7 ++
drivers/tty/serdev/Kconfig | 11 ++
drivers/tty/serdev/Makefile | 2 +
drivers/tty/serdev/core.c | 133 +++++++++++++++++++++--
drivers/tty/serdev/serdev-ttydev.c | 70 ++++++++++++
drivers/tty/serdev/serdev-ttyport.c | 10 +-
drivers/tty/serdev/serport.h | 16 +++
include/linux/mod_devicetable.h | 10 ++
include/linux/serdev.h | 4 +
scripts/mod/devicetable-offsets.c | 3 +
scripts/mod/file2alias.c | 11 ++
15 files changed, 304 insertions(+), 15 deletions(-)
create mode 100644 drivers/tty/serdev/serdev-ttydev.c
create mode 100644 drivers/tty/serdev/serport.h

--
2.17.0

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