kernel/linux.git/drivers/tty/serial/bcm63xx_uart.c, branch v6.19.11

serial: Switch back to struct platform_driver::remove()

2024-10-11T06:13:28+00:00

After commit 0edb555a65d1 ("platform: Make platform_driver::remove() return void") .remove() is (again) the right callback to implement for platform drivers. Convert all platform drivers below drivers/tty/serial to use .remove(), with the eventual goal to drop struct platform_driver::remove_new(). As .remove() and .remove_new() have the same prototypes, conversion is done by just changing the structure member name in the driver initializer. Signed-off-by: Uwe Kleine-König Link: https://lore.kernel.org/r/20241007205803.444994-7-u.kleine-koenig@baylibre.com Signed-off-by: Greg Kroah-Hartman

serial: bcm63xx-uart: fix tx after conversion to uart_port_tx_limited()

2024-06-24T14:14:48+00:00

When bcm63xx-uart was converted to uart_port_tx_limited(), it implicitly added a call to stop_tx(). This causes garbage to be put out on the serial console. To fix this, pass UART_TX_NOSTOP in flags, and manually call stop_tx() ourselves analogue to how a similar issue was fixed in commit 7be50f2e8f20 ("serial: mxs-auart: fix tx"). Fixes: d11cc8c3c4b6 ("tty: serial: use uart_port_tx_limited()") Cc: stable@vger.kernel.org Signed-off-by: Jonas Gorski Signed-off-by: Doug Brown Link: https://lore.kernel.org/r/20240606195632.173255-4-doug@schmorgal.com Signed-off-by: Greg Kroah-Hartman

serial: bcm63xx: Use uart_prepare_sysrq_char().

2024-03-02T21:06:20+00:00

The port lock is a spinlock_t which is becomes a sleeping lock on PREEMPT_RT. The driver splits the locking function into two parts: local_irq_save() and uart_port_lock() and this breaks PREEMPT_RT. Delay handling sysrq until port lock is dropped. Remove the special case in the console write routine an always use the complete locking function. Signed-off-by: Sebastian Andrzej Siewior Link: https://lore.kernel.org/r/20240301215246.891055-4-bigeasy@linutronix.de Signed-off-by: Greg Kroah-Hartman

serial: bcm63xx: Convert to platform remove callback returning void

2023-11-23T19:12:30+00:00

The .remove() callback for a platform driver returns an int which makes many driver authors wrongly assume it's possible to do error handling by returning an error code. However the value returned is ignored (apart from emitting a warning) and this typically results in resource leaks. To improve here there is a quest to make the remove callback return void. In the first step of this quest all drivers are converted to .remove_new(), which already returns void. Eventually after all drivers are converted, .remove_new() will be renamed to .remove(). Trivially convert this driver from always returning zero in the remove callback to the void returning variant. Signed-off-by: Uwe Kleine-König Reviewed-by: Florian Fainelli Link: https://lore.kernel.org/r/20231110152927.70601-10-u.kleine-koenig@pengutronix.de Signed-off-by: Greg Kroah-Hartman

serial: bcm63xx-uart: Use port lock wrappers

2023-09-18T09:18:10+00:00

When a serial port is used for kernel console output, then all modifications to the UART registers which are done from other contexts, e.g. getty, termios, are interference points for the kernel console. So far this has been ignored and the printk output is based on the principle of hope. The rework of the console infrastructure which aims to support threaded and atomic consoles, requires to mark sections which modify the UART registers as unsafe. This allows the atomic write function to make informed decisions and eventually to restore operational state. It also allows to prevent the regular UART code from modifying UART registers while printk output is in progress. All modifications of UART registers are guarded by the UART port lock, which provides an obvious synchronization point with the console infrastructure. To avoid adding this functionality to all UART drivers, wrap the spin_[un]lock*() invocations for uart_port::lock into helper functions which just contain the spin_[un]lock*() invocations for now. In a subsequent step these helpers will gain the console synchronization mechanisms. Converted with coccinelle. No functional change. Signed-off-by: Thomas Gleixner Reviewed-by: Florian Fainelli Signed-off-by: John Ogness Link: https://lore.kernel.org/r/20230914183831.587273-23-john.ogness@linutronix.de Signed-off-by: Greg Kroah-Hartman

serial: bcm63xx-uart: Use devm_platform_get_and_ioremap_resource()

2023-07-25T18:25:52+00:00

Convert platform_get_resource(), devm_ioremap_resource() to a single call to devm_platform_get_and_ioremap_resource(), as this is exactly what this function does. Signed-off-by: Yangtao Li Link: https://lore.kernel.org/r/20230712062853.11007-2-frank.li@vivo.com Signed-off-by: Greg Kroah-Hartman

serial: bcm63xx-uart: add polling support

2023-03-29T08:54:23+00:00

The tty framework can support polling console to allow operation in situations where interrupts are turned off. Adding polling mode support allows using KGDB over serial console, Signed-off-by: Arend van Spriel Link: https://lore.kernel.org/r/20230322223956.84647-1-arend.vanspriel@broadcom.com Signed-off-by: Greg Kroah-Hartman

tty: serial: use uart_port_tx_limited()

2022-11-03T02:32:40+00:00

uart_port_tx_limited() is a new helper to send characters to the device. Use it in these drivers. mux.c also needs to define tx_done(). But I'm not sure if the driver really wants to wait for all the characters to dismiss from the HW fifo at this code point. Hence I marked this as FIXME. Cc: Russell King Cc: Florian Fainelli Cc: bcm-kernel-feedback-list@broadcom.com Cc: "Pali Rohár" Cc: Kevin Cernekee Cc: Palmer Dabbelt Cc: Paul Walmsley Cc: Orson Zhai Cc: Baolin Wang Cc: Chunyan Zhang Cc: Patrice Chotard Cc: linux-riscv@lists.infradead.org Reviewed-by: Ilpo Järvinen Signed-off-by: Jiri Slaby (SUSE) Link: https://lore.kernel.org/r/20221004104927.14361-4-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman

serial: Make ->set_termios() old ktermios const

2022-08-30T12:22:35+00:00

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: make uart_console_write->putchar()'s character an unsigned char

2022-03-03T14:06:31+00:00

Currently, uart_console_write->putchar's second parameter (the character) is of type int. It makes little sense, provided uart_console_write() accepts the input string as "const char *s" and passes its content -- the characters -- to putchar(). So switch the character's type to unsigned char. We don't use char as that is signed on some platforms. That would cause troubles for drivers which (implicitly) cast the char to u16 when writing to the device. Sign extension would happen in that case and the value written would be completely different to the provided char. DZ is an example of such a driver -- on MIPS, it uses u16 for dz_out in dz_console_putchar(). Note we do the char -> uchar conversion implicitly in uart_console_write(). Provided we do not change size of the data type, sign extension does not happen there, so the problem is void. This makes the types consistent and unified with the rest of the uart layer, which uses unsigned char in most places already. One exception is xmit_buf, but that is going to be converted later. Cc: Paul Cercueil Cc: Tobias Klauser Cc: Russell King Cc: Vineet Gupta Cc: Nicolas Ferre Cc: Alexandre Belloni Cc: Ludovic Desroches Cc: Florian Fainelli Cc: bcm-kernel-feedback-list@broadcom.com Cc: Alexander Shiyan Cc: Baruch Siach Cc: "Maciej W. Rozycki" Cc: Paul Walmsley Cc: Palmer Dabbelt Cc: Albert Ou Cc: Shawn Guo Cc: Sascha Hauer Cc: Pengutronix Kernel Team Cc: Fabio Estevam Cc: NXP Linux Team Cc: Karol Gugala Cc: Mateusz Holenko Cc: Vladimir Zapolskiy Cc: Neil Armstrong Cc: Kevin Hilman Cc: Jerome Brunet Cc: Martin Blumenstingl Cc: Taichi Sugaya Cc: Takao Orito Cc: Liviu Dudau Cc: Sudeep Holla Cc: Lorenzo Pieralisi Cc: "Andreas Färber" Cc: Manivannan Sadhasivam Cc: Michael Ellerman Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Andy Gross Cc: Bjorn Andersson Cc: Krzysztof Kozlowski Cc: Orson Zhai Cc: Baolin Wang Cc: Chunyan Zhang Cc: Patrice Chotard Cc: Maxime Coquelin Cc: Alexandre Torgue Cc: "David S. Miller" Cc: Peter Korsgaard Cc: Michal Simek Acked-by: Richard Genoud [atmel_serial] Acked-by: Uwe Kleine-König Acked-by: Paul Cercueil Acked-by: Neil Armstrong # meson_serial Signed-off-by: Jiri Slaby Link: https://lore.kernel.org/r/20220303080831.21783-1-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman