kernel/drivers/usb/serial/xr_serial.c, branch linux-6.5.y

USB: serial: return errors from break handling

2023-06-07T15:00:23Z

Start propagating errors to user space when setting the break state fails. This will be used by follow-on changes to also report when a driver or device does not support break control. Tested-by: Corey Minyard Signed-off-by: Johan Hovold

USB: serial: xr: avoid requesting zero DTE rate

2022-11-30T11:28:51Z

When the requested line speed is B0 (hangup) there is no need to use the current speed in the line-coding request. This specifically avoids requesting a zero DTE rate when the current speed is B0, which could potentially confuse buggy firmware. Reviewed-by: Greg Kroah-Hartman Signed-off-by: Johan Hovold

usb: serial: Make ->set_termios() old ktermios const

2022-08-30T12:22:35Z

There should be no reason to adjust old ktermios which is going to get discarded anyway. Reviewed-by: Andy Shevchenko Signed-off-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20220816115739.10928-8-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman

USB: serial: xr: add copyright notice

2021-04-13T16:36:39Z

Add another copyright notice for the work done in 2021. Signed-off-by: Johan Hovold

USB: serial: xr: reset FIFOs on open

2021-04-13T16:36:38Z

Reset the transmit and receive FIFOs before enabling the UARTs as part of open() in order to flush any stale data. Note that the XR21V141X needs a type-specific implementation due to its UART Manager registers. Signed-off-by: Johan Hovold

USB: serial: xr: add support for XR22801, XR22802, XR22804

2021-04-13T16:36:37Z

The XR22801, XR22802 and XR22804 are compound devices with an embedded hub and up to seven downstream USB devices including one, two or four UARTs respectively. The UART function is similar to XR21B142X but most registers are offset by 0x40, the register requests are different and are directed at the device rather than interface, and 5 and 6-bit words are not supported. Signed-off-by: Johan Hovold

USB: serial: xr: add support for XR21B1411

2021-04-13T16:36:35Z

The single-port XR21B1411 is similar to the XR21B142X type but uses 12-bit registers and 16-bit register addresses, the register requests are different and are directed at the device rather than interface, and 5 and 6-bit words are not supported. The register layout is very similar to XR21B142X except that most registers are offset by 0xc00 (corresponding to a channel index of 12 in the MSB of wIndex). As the device is single-port so that the derived channel index is 0, the current register accessors can be reused after simply changing the address width. Signed-off-by: Johan Hovold

USB: serial: xr: add support for XR21B1421, XR21B1422 and XR21B1424

2021-04-13T16:36:33Z

The XR21B1421, XR21B1422 and XR21B1424 are the one-, two- and four-port models of a second XR21B142X type of the Maxlinear/Exar USB UARTs. The XR21B142X type differs from XR21V141X in several ways, including: - register layout - register width (16-bit instead of 8-bit) - vendor register requests - UART enable/disable sequence - custom-driver mode flag - three additional GPIOs (9 instead of 6) As for XR21V141X, the XR21B142X vendor requests encode the channel index in the MSB of wIndex, but it lacks the UART Manager registers which have been replaced by regular UART registers. The new type also uses the interface number of the control interface (0, 2, 4, 6) as channel index instead of the channel number (0, 1, 2, 3). The XR21B142X lacks the divisor and format registers used by XR21V141X and instead uses the CDC SET_LINE_CONTROL request to configure the line settings. Note that the currently supported XR21V141X type lacks the custom-driver mode flag that prevents the device from entering CDC-ACM mode when a CDC requests is received. This specifically means that the SET_LINE_CONTROL request cannot be used with XR21V141X even though it is otherwise supported. The UART enable sequence for XR21B142X does not involve explicitly enabling the FIFOs, but according to datasheet the UART must be disabled when writing any register but GPIO_SET, GPIO_CLEAR, TX_BREAK and ERROR_STATUS. Signed-off-by: Johan Hovold

USB: serial: xr: add type abstraction

2021-04-13T16:36:31Z

There are at least four types of Maxlinear/Exar USB UARTs which differ in various ways such as in their register layouts: XR21V141X XR21B142X XR21B1411 XR22804 It is not clear whether the device type can be inferred from the descriptors so encode it in the device-id table for now. Add a type structure that can be used to abstract the register layout and other features, and use it when accessing the XR21V141X UART registers that are shared by all types. Note that the currently supported XR21V141X type is the only type that has a set of UART Manager registers and that these will need to be handled specifically. Similarly, XR21V141X is the only type which has the divisor registers and that needs to use the format register when configuring the line settings. Signed-off-by: Johan Hovold

USB: serial: xr: drop type prefix from shared defines

2021-04-13T16:36:30Z

In preparation for adding support for further types, drop the type prefix from defines that are not specific to XR21V141X. Signed-off-by: Johan Hovold