kernel/drivers/tty/serial/8250/8250_dwlib.c, branch linux-6.9.y

serial: 8250_dw: Don't use struct dw8250_data outside of 8250_dw

2024-06-21T12:40:38Z

[ Upstream commit 87d80bfbd577912462061b1a45c0ed9c7fcb872f ] The container of the struct dw8250_port_data is private to the actual driver. In particular, 8250_lpss and 8250_dw use different data types that are assigned to the UART port private_data. Hence, it must not be used outside the specific driver. Currently the only cpr_val is required by the common code, make it be available via struct dw8250_port_data. This fixes the UART breakage on Intel Galileo boards. Fixes: 593dea000bc1 ("serial: 8250: dw: Allow to use a fallback CPR value if not synthesized") Signed-off-by: Andy Shevchenko Link: https://lore.kernel.org/r/20240514190730.2787071-2-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

serial: 8250_dw: Do not bailout on UCV read returning zero

2024-01-04T15:21:43Z

Designware UART has optional feature FIFO_MODE to implement FIFO. Encoding FIFO capabilities through Component Parameter Register CPR is optional and it can be enabled using parameter UART_ADD_ENCODED_PARAMS. Driver can exercise fifo capabilities by decoding CPR if implemented or from cpr_val provided from the dw8250_platform_data otherwise. dw8250_setup_port() checks for CPR or cpr_val to determine FIFO size only when Component Version (UCV) is non-zero. Bailing out early on UCV read returning zero will leave fifosize as zero and !UART_CAP_FIFO, hence prevent early return and continue to process CPR or cpr_val for the driver to utilize FIFO. Non-zero UCV implies ADDITIONAL_FEATURES=1, preventing early return will not be an overhead here. Signed-off-by: Vamshi Gajjela Link: https://lore.kernel.org/r/20231231182951.877805-1-vamshigajjela@google.com Signed-off-by: Greg Kroah-Hartman

serial: 8250_dw: Decouple DLF register check from UCV

2023-11-28T19:24:14Z

Designware UART has an optional feature to enable Fractional Baud Rate Divisor (DLF) through the FRACTIONAL_BAUD_DIVISOR_EN configuration parameter, and it is not dependent on ADDITIONAL_FEATURES. dw8250_setup_port() checks DLF to determine dlf_size only when UART Component Version (UCV) is non-zero. As mentioned above DLF and UCV are independent features. Move the logic corresponding to DLF size calculation ahead of the UCV check to prevent early return. Otherwise, dlf_size will be zero and driver will not be able to use the controller's fractional baud rate divisor (DLF) feature. Signed-off-by: Vamshi Gajjela Link: https://lore.kernel.org/r/20231126160420.2442330-1-vamshigajjela@google.com Signed-off-by: Greg Kroah-Hartman

serial: 8250_dw: Preserve original value of DLF register

2023-07-25T18:31:31Z

Preserve the original value of the Divisor Latch Fraction (DLF) register. When the DLF register is modified without preservation, it can disrupt the baudrate settings established by firmware or bootloader, leading to data corruption and the generation of unreadable or distorted characters. Fixes: 701c5e73b296 ("serial: 8250_dw: add fractional divisor support") Cc: stable Signed-off-by: Ruihong Luo Link: https://lore.kernel.org/stable/20230713004235.35904-1-colorsu1922%40gmail.com Reviewed-by: Ilpo Järvinen Reviewed-by: Andy Shevchenko Link: https://lore.kernel.org/r/20230713004235.35904-1-colorsu1922@gmail.com Signed-off-by: Greg Kroah-Hartman

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/20220816115739.10928-7-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman

serial: 8250_dwlib: remove redundant sanity check for RS485 flags

2022-07-14T14:34:24Z

Before the drivers rs485_config() function is called the serial core already ensures that only one of both options RTS on send or RTS after send is set. So remove the concerning sanity check in the driver function to avoid redundancy. Reviewed-by: Ilpo Järvinen Signed-off-by: Lino Sanfilippo Link: https://lore.kernel.org/r/20220710164442.2958979-8-LinoSanfilippo@gmx.de Signed-off-by: Greg Kroah-Hartman

serial: Embed rs485_supported to uart_port

2022-07-08T13:14:09Z

Embed rs485_supported to uart_port to allow serial core to tweak it as needed. Reviewed-by: Lino Sanfilippo Signed-off-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20220704094515.6831-2-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman

8250_dwlib: Convert bitops to newer form

2022-06-30T15:11:03Z

Instead of open-coding, use BIT(), GENMASK(), and FIELD_GET() helpers. Reviewed-by: Andy Shevchenko Signed-off-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20220630100536.41329-1-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman

serial: 8250_dwlib: Support for 9th bit multipoint addressing

2022-06-27T12:44:20Z

Add 9th bit multipoint addressing mode for DW UART. 9th bit addressing can be used only when HW RS485 is available. Updating RAR (receive address register) is bit tricky because busy indication is not be available when DW UART is strictly 16550 compatible, which is the case with the hardware I was testing with. RAR should not be updated while receive is in progress which is now achieved by deasserting RE and waiting for one frame (in case rx would be in progress, the driver seems to have no way of knowing it w/o busy indication). Because of this complexity, it's better to avoid doing it unless really needed. Co-developed-by: Heikki Krogerus Co-developed-by: Andy Shevchenko Co-developed-by: Raymond Tan Co-developed-by: Lakshmi Sowjanya Signed-off-by: Heikki Krogerus Signed-off-by: Andy Shevchenko Signed-off-by: Raymond Tan Signed-off-by: Lakshmi Sowjanya Signed-off-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20220624204210.11112-7-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman

serial: take termios_rwsem for ->rs485_config() & pass termios as param

2022-06-27T12:44:20Z

To be able to alter ADDRB within ->rs485_config(), take termios_rwsem before calling ->rs485_config() and pass termios. Signed-off-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20220624204210.11112-5-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman