kernel/linux.git/drivers/tty/serial/altera_uart.c, branch v5.19

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

serial: altera: Use platform_get_irq_optional() to get the interrupt

2021-12-30T12:26:48+00:00

platform_get_resource(pdev, IORESOURCE_IRQ, ..) relies on static allocation of IRQ resources in DT core code, this causes an issue when using hierarchical interrupt domains using "interrupts" property in the node as this bypasses the hierarchical setup and messes up the irq chaining. In preparation for removal of static setup of IRQ resource from DT core code use platform_get_irq_optional(). Signed-off-by: Lad Prabhakar Link: https://lore.kernel.org/r/20211224142917.6966-2-prabhakar.mahadev-lad.rj@bp.renesas.com Signed-off-by: Greg Kroah-Hartman

serial: altera_uart: drop low-latency workaround

2021-04-22T10:09:24+00:00

Commit dd085ed8ef6c ("tty: serial: altera: drop uart_port->lock before calling tty_flip_buffer_push()") claimed to address a locking issue but only provided a dubious lockdep splat from an unrelated driver, which in the end turned out to be due a broken local change carried by the author. Unfortunately these patches were merged before the issue had been analysed properly so the commit messages makes no sense whatsoever. The real issue was first seen on RT which at the time effectively always set the low_latency flag for all serial drivers by patching tty_flip_buffer_push(). This in turn revealed that many drivers did not handle the infamous low_latency behaviour which meant that data was pushed immediately to the line discipline instead of being deferred to a work queue. Since commit a9c3f68f3cd8 ("tty: Fix low_latency BUG"), tty_flip_buffer_push() always schedules a work item to push data to the line discipline and there's no need to keep any low_latency hacks around. Link: https://lore.kernel.org/linux-serial/cover.1376923198.git.viresh.kumar@linaro.org/ Cc: Tobias Klauser Acked-by: Tobias Klauser Signed-off-by: Johan Hovold Link: https://lore.kernel.org/r/20210421095509.3024-4-johan@kernel.org Signed-off-by: Greg Kroah-Hartman

serial: altera: set RRDY flag also without irq

2018-02-28T12:30:09+00:00

The UART can be operated without an irq. In this case a timer is setup that regularily calls altera_uart_interrupt(). The receiving part depends on pp->imr having the bit ALTERA_UART_STATUS_RRDY_MSK set, otherwise altera_uart_rx_chars() is never called. So ensure that the bit gets set (disguised as ALTERA_UART_CONTROL_RRDY_MSK) by not returning early from altera_uart_startup() if port->irq is 0. This doesn't affect the hardware as the ALTERA_UART_CONTROL_RRDY_MSK bit isn't actually written to the control register. Signed-off-by: Uwe Kleine-König Acked-by: Tobias Klauser Signed-off-by: Greg Kroah-Hartman

serial: altera: don't enable any irq if the device doesn't feature an irq

2018-02-28T12:30:09+00:00

If the irq line of an altera UART device isn't used to report interrupts for this device the driver better ensures that this device doesn't pull this line to active state and so disturb the whatever might be connected to this line. Signed-off-by: Uwe Kleine-König Acked-by: Tobias Klauser Signed-off-by: Greg Kroah-Hartman

serial: altera: ensure port->regshift is honored consistently

2018-02-28T12:30:09+00:00

Most register accesses in the altera driver honor port->regshift by using altera_uart_writel(). There are a few accesses however that were missed when the driver was converted to use port->regshift and some others were added later in commit 4d9d7d896d77 ("serial: altera_uart: add earlycon support"). Fixes: 2780ad42f5fe ("tty: serial: altera_uart: Use port->regshift to store bus shift") Signed-off-by: Uwe Kleine-König Acked-by: Tobias Klauser Signed-off-by: Greg Kroah-Hartman

tty: serial: Remove redundant license text

2017-11-08T12:08:12+00:00

Now that the SPDX tag is in all tty files, that identifies the license in a specific and legally-defined manner. So the extra GPL text wording can be removed as it is no longer needed at all. This is done on a quest to remove the 700+ different ways that files in the kernel describe the GPL license text. And there's unneeded stuff like the address (sometimes incorrect) for the FSF which is never needed. No copyright headers or other non-license-description text was removed. Cc: Jiri Slaby Cc: Eric Anholt Cc: Stefan Wahren Cc: Florian Fainelli Cc: Ray Jui Cc: Scott Branden Cc: bcm-kernel-feedback-list@broadcom.com Cc: "James E.J. Bottomley" Cc: Helge Deller Cc: Joachim Eastwood Cc: Matthias Brugger Cc: Masahiro Yamada Cc: Tobias Klauser Cc: Russell King Cc: Vineet Gupta Cc: Richard Genoud Cc: Alexander Shiyan Cc: Baruch Siach Cc: Pat Gefre Cc: "Guilherme G. Piccoli" Cc: Jason Wessel Cc: Vladimir Zapolskiy Cc: Sylvain Lemieux Cc: Carlo Caione Cc: Kevin Hilman Cc: Liviu Dudau Cc: Sudeep Holla Cc: Lorenzo Pieralisi Cc: Andy Gross Cc: David Brown Cc: "Andreas Färber" Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Michael Ellerman Cc: Kevin Cernekee Cc: Laxman Dewangan Cc: Thierry Reding Cc: Jonathan Hunter Cc: Barry Song Cc: Patrice Chotard Cc: Maxime Coquelin Cc: Alexandre Torgue Cc: Chris Metcalf Cc: Peter Korsgaard Cc: Timur Tabi Cc: Tony Prisk Cc: Michal Simek Cc: "Sören Brinkmann" Signed-off-by: Greg Kroah-Hartman

tty: add SPDX identifiers to all remaining files in drivers/tty/

2017-11-08T12:08:12+00:00

It's good to have SPDX identifiers in all files to make it easier to audit the kernel tree for correct licenses. Update the drivers/tty files files with the correct SPDX license identifier based on the license text in the file itself. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This work is based on a script and data from Thomas Gleixner, Philippe Ombredanne, and Kate Stewart. Cc: Jiri Slaby Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Michael Ellerman Cc: Chris Metcalf Cc: Jiri Kosina Cc: David Sterba Cc: James Hogan Cc: Rob Herring Cc: Eric Anholt Cc: Stefan Wahren Cc: Florian Fainelli Cc: Ray Jui Cc: Scott Branden Cc: bcm-kernel-feedback-list@broadcom.com Cc: "James E.J. Bottomley" Cc: Helge Deller Cc: Joachim Eastwood Cc: Matthias Brugger Cc: Masahiro Yamada Cc: Tobias Klauser Cc: Russell King Cc: Vineet Gupta Cc: Richard Genoud Cc: Alexander Shiyan Cc: Baruch Siach Cc: "Maciej W. Rozycki" Cc: "Uwe Kleine-König" Cc: Pat Gefre Cc: "Guilherme G. Piccoli" Cc: Jason Wessel Cc: Vladimir Zapolskiy Cc: Sylvain Lemieux Cc: Carlo Caione Cc: Kevin Hilman Cc: Liviu Dudau Cc: Sudeep Holla Cc: Lorenzo Pieralisi Cc: Andy Gross Cc: David Brown Cc: "Andreas Färber" Cc: Kevin Cernekee Cc: Laxman Dewangan Cc: Thierry Reding Cc: Jonathan Hunter Cc: Barry Song Cc: Patrice Chotard Cc: Maxime Coquelin Cc: Alexandre Torgue Cc: "David S. Miller" Cc: Peter Korsgaard Cc: Timur Tabi Cc: Tony Prisk Cc: Michal Simek Cc: "Sören Brinkmann" Cc: Thomas Gleixner Cc: Kate Stewart Cc: Philippe Ombredanne Cc: Jiri Slaby Signed-off-by: Greg Kroah-Hartman

tty/serial: altera_uart: Convert timers to use timer_setup()

2017-11-04T11:01:54+00:00

In preparation for unconditionally passing the struct timer_list pointer to all timer callbacks, switch to using the new timer_setup() and from_timer() to pass the timer pointer explicitly. Cc: Tobias Klauser Cc: Jiri Slaby Cc: linux-serial@vger.kernel.org Cc: nios2-dev@lists.rocketboards.org Signed-off-by: Kees Cook Acked-by: Tobias Klauser Signed-off-by: Greg Kroah-Hartman

serial: altera_uart: call iounmap() at driver remove

2017-05-25T12:36:37+00:00

The driver calls ioremap() in the probe function but doesn't call iounmap() in the remove function correspondingly. Do so now. Follow commit 5c9d6abed9e0 ("serial: altera_jtaguart: adding iounmap()") Cc: Alexey Khoroshilov Signed-off-by: Tobias Klauser Signed-off-by: Greg Kroah-Hartman