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path: root/drivers/tty/serial/8250/8250_dwlib.c
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2024-08-07serial: remove quot_frac from serial8250_do_set_divisor()Jiri Slaby (SUSE)
quot_frac is unused in serial8250_do_set_divisor() since commit b2b4b8ed3c06 (serial: 8250_exar: Move custom divisor support out from 8250_port). So no point to pass it. Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> Cc: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20240805102046.307511-5-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-06-04serial: 8250_dw: Don't use struct dw8250_data outside of 8250_dwAndy Shevchenko
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 <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20240514190730.2787071-2-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-04serial: 8250_dw: Do not bailout on UCV read returning zeroVamshi Gajjela
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 <vamshigajjela@google.com> Link: https://lore.kernel.org/r/20231231182951.877805-1-vamshigajjela@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-11-28serial: 8250_dw: Decouple DLF register check from UCVVamshi Gajjela
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 <vamshigajjela@google.com> Link: https://lore.kernel.org/r/20231126160420.2442330-1-vamshigajjela@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-07-25serial: 8250_dw: Preserve original value of DLF registerRuihong Luo
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 <stable@kernel.org> Signed-off-by: Ruihong Luo <colorsu1922@gmail.com> Link: https://lore.kernel.org/stable/20230713004235.35904-1-colorsu1922%40gmail.com Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20230713004235.35904-1-colorsu1922@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-30serial: Make ->set_termios() old ktermios constIlpo Järvinen
There should be no reason to adjust old ktermios which is going to get discarded anyway. Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220816115739.10928-7-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-07-14serial: 8250_dwlib: remove redundant sanity check for RS485 flagsLino Sanfilippo
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 <ilpo.jarvinen@linux.intel.com> Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> Link: https://lore.kernel.org/r/20220710164442.2958979-8-LinoSanfilippo@gmx.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-07-08serial: Embed rs485_supported to uart_portIlpo Järvinen
Embed rs485_supported to uart_port to allow serial core to tweak it as needed. Reviewed-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220704094515.6831-2-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-308250_dwlib: Convert bitops to newer formIlpo Järvinen
Instead of open-coding, use BIT(), GENMASK(), and FIELD_GET() helpers. Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220630100536.41329-1-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-27serial: 8250_dwlib: Support for 9th bit multipoint addressingIlpo Järvinen
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 <heikki.krogerus@linux.intel.com> Co-developed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Co-developed-by: Raymond Tan <raymond.tan@intel.com> Co-developed-by: Lakshmi Sowjanya <lakshmi.sowjanya.d@intel.com> Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Raymond Tan <raymond.tan@intel.com> Signed-off-by: Lakshmi Sowjanya <lakshmi.sowjanya.d@intel.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220624204210.11112-7-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-27serial: take termios_rwsem for ->rs485_config() & pass termios as paramIlpo Järvinen
To be able to alter ADDRB within ->rs485_config(), take termios_rwsem before calling ->rs485_config() and pass termios. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220624204210.11112-5-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-10serial: 8250_dwlib: Remove serial_rs485 sanitizationIlpo Järvinen
Serial core handles serial_rs485 sanitization and rs485 struct assignment. As serial_rs485 is already clear for the non-RS485 case by serial core, there no need to clear flags in the driver. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220606100433.13793-26-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-10serial: 8250_dwlib: Fill in rs485_supportedIlpo Järvinen
Add information on supported serial_rs485 features. When the driver is using em485, take advantage of serial8250_em485_supported. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220606100433.13793-7-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-26serial: 8250_dwlib: Implement SW half duplex supportIlpo Järvinen
This patch enables support for SW half-duplex mode using em485. Cc: Eric Tremblay <etremblay@distech-controls.com> Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Tested-by: Vicente Bergas <vicencb@gmail.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220426122448.38997-3-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-26serial: 8250_dwlib: RS485 HW half & full duplex supportIlpo Järvinen
The Synopsys DesignWare UART can be configured to have HW support for the RS485 protocol from IP version 4.0 onward. Add support for hardware-controlled half duplex and full duplex modes. HW will take care of managing DE and RE, the driver just gives it permission to use either by setting both to 1. To ask for full duplex mode, userspace sets SER_RS485_RX_DURING_TX flag and HW will take care of the rest. Set delay_rts_before_send and delay_rts_after_send to zero for now. The granularity of that ABI is too coarse to be useful. Co-developed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Co-developed-by: Raymond Tan <raymond.tan@intel.com> Signed-off-by: Raymond Tan <raymond.tan@intel.com> Co-developed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220426122448.38997-2-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-26serial: 8250: dw: Move the IO accessors to 8250_dwlib.hMiquel Raynal
These accessors should be used instead of the regular readl/writel() helpers. In order to use them also from 8250_dw.c in this directory, move the helpers to 8250_dwlib.h There is no functional change. There is no need for declaring `struct uart_port` or even UPIO_MEM32BE which both are already included in the 8250_dwlib.h header by 8250.h. Suggested-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Link: https://lore.kernel.org/r/20220422180615.9098-8-miquel.raynal@bootlin.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-26serial: 8250: dw: Allow to use a fallback CPR value if not synthesizedMiquel Raynal
DW UART controllers can be synthesized without the CPR register. In this case, allow to the platform information to provide a CPR value. Co-developed-by: Phil Edworthy <phil.edworthy@renesas.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Phil Edworthy <phil.edworthy@renesas.com> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Link: https://lore.kernel.org/r/20220422180615.9098-5-miquel.raynal@bootlin.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-10-10serial: 8250_lpss: Extract dw8250_do_set_termios() for common useAndy Shevchenko
Some of the code currently used in dw8250_set_termios(), byt_set_termios() may be reused by other methods in the future. Extract it to a common helper function. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20211005133026.21488-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-04serial: 8250_dw: split Synopsys DesignWare 8250 common functionsAndy Shevchenko
We would like to use same functions in the couple of drivers for Synopsys DesignWare 8250 UART. Split them from 8250_dw into new brand library module which users will select explicitly. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Link: https://lore.kernel.org/r/20190806094322.64987-3-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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