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path: root/drivers/tty/serial/8250/8250_bcm2835aux.c
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2020-09-04serial: 8250: Simplify with dev_err_probe()Krzysztof Kozlowski
Common pattern of handling deferred probe can be simplified with dev_err_probe(). Less code and the error value gets printed. Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> Acked-by: Florian Fainelli <f.fainelli@gmail.com> Reviewed-by: Lukas Wunner <lukas@wunner.de> Link: https://lore.kernel.org/r/20200901153100.18827-1-krzk@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-07serial: 8250_bcm2835aux: Support rs485 software emulationLukas Wunner
Amend 8250_bcm2835aux.c to support rs485 as introduced for 8250_omap.c by commit e490c9144cfa ("tty: Add software emulated RS485 support for 8250"). The bcm2835aux differs from omap chips by inverting the meaning of RTS in the MCR register: If the bit is clear, RTS is high. With omap, it's apparently the other way round. Moreover, omap achieves half-duplex mode by disabling the UART_IER_RDI interrupt and clearing the RX FIFO when TX stops. This approach doesn't work on bcm2835aux because the UART_LSR_DR bit is set even when UART_IER_RDI is disabled. Consequently, serial8250_handle_irq() invokes serial8250_rx_chars() to empty the FIFO and characters are received even though the user requested half-duplex. Solve by disabling the receiver using the non-standard CNTL register. Cache that register in the driver's private data for performance. Set the private data pointer before calling serial8250_register_8250_port() to prevent a null pointer deref in case one of the rs485 callbacks is invoked immediately after port registration. Signed-off-by: Lukas Wunner <lukas@wunner.de> Cc: Matwey V. Kornilov <matwey@sai.msu.ru> Link: https://lore.kernel.org/r/dd86460e20a8f979b7272a0bde73640312b902b1.1582895077.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-10serial: 8250_early: Add earlycon for BCM2835 aux uartMatthias Brugger
Define the OF early console for BCM2835 aux UART, which can be enabled by passing "earlycon" on the boot command line. This UART is found on BCM283x and BCM27xx SoCs, a.k.a. Raspberry Pi in its variants. Signed-off-by: Matthias Brugger <mbrugger@suse.com> Link: https://lore.kernel.org/r/20200126123314.3558-1-matthias.bgg@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-22serial: 8250_bcm2835aux: Document struct bcm2835aux_dataLukas Wunner
Document the driver private data of the BCM2835 auxiliary UART so that upcoming commits may add further members with proper kerneldoc. Signed-off-by: Lukas Wunner <lukas@wunner.de> Reviewed-by: Matthias Brugger <mbrugger@suse.com> Reviewed-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> Tested-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> Link: https://lore.kernel.org/r/aea363c27fd541dba96d2ebfeee4f596c6d34932.1579175223.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-22serial: 8250_bcm2835aux: Use generic remapping codeLukas Wunner
On probe the bcm2835aux UART driver misreports the register base address as 0x0: ttyS0 at MMIO 0x0 (irq = 53, base_baud = 50000000) is a 16550 That's because the driver remaps the registers itself. Take advantage of the generic remapping code in serial8250_request_std_resource() to get a message with the correct address and to simplify the driver. Signed-off-by: Lukas Wunner <lukas@wunner.de> Cc: Martin Sperl <kernel@martin.sperl.org> Reviewed-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> Tested-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> Link: https://lore.kernel.org/r/7d1a9bdb05090d8e465fd15cd26d6e81538d07f9.1579175223.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-22serial: 8250_bcm2835aux: Allocate uart_8250_port on stackLukas Wunner
The bcm2835aux UART driver stores a struct uart_8250_port in its private data even though it's only passed once to serial8250_register_8250_port() (which copies all relevant data) and becomes obsolete afterwards. Allocate the struct on the stack instead for simplicity and to conserve memory. The driver also initializes a spinlock in the struct which is never used. Drop that as well. Signed-off-by: Lukas Wunner <lukas@wunner.de> Cc: Martin Sperl <kernel@martin.sperl.org> Reviewed-by: Matthias Brugger <mbrugger@suse.com> Reviewed-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> Tested-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> Link: https://lore.kernel.org/r/421d3aed4c34cc8447ac9c26c320961f1b787f11.1579175223.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-22serial: 8250_bcm2835aux: Suppress register_port error on -EPROBE_DEFERLukas Wunner
Suppress a gratuitous error message if serial8250_register_8250_port() returns -EPROBE_DEFER. Signed-off-by: Lukas Wunner <lukas@wunner.de> Reviewed-by: Matthias Brugger <mbrugger@suse.com> Reviewed-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> Tested-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> Link: https://lore.kernel.org/r/6aea0eacf3bfa73fe2d81082cc723265413410c8.1579175223.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-22serial: 8250_bcm2835aux: Suppress clk_get error on -EPROBE_DEFERPhil Elwell
Suppress a gratuitous error message if devm_clk_get() returns -EPROBE_DEFER. Signed-off-by: Phil Elwell <phil@raspberrypi.org> [lukas: extend commit message] Signed-off-by: Lukas Wunner <lukas@wunner.de> Reviewed-by: Matthias Brugger <mbrugger@suse.com> Reviewed-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> Tested-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> Link: https://lore.kernel.org/r/deafc13cdfd7a31c6a81b0db95adcd3599accc26.1579175223.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-22serial: 8250_bcm2835aux: Fix line mismatch on driver unbindLukas Wunner
Unbinding the bcm2835aux UART driver raises the following error if the maximum number of 8250 UARTs is set to 1 (via the 8250.nr_uarts module parameter or CONFIG_SERIAL_8250_RUNTIME_UARTS): (NULL device *): Removing wrong port: a6f80333 != fa20408b That's because bcm2835aux_serial_probe() retrieves UART line number 1 from the devicetree and stores it in data->uart.port.line, while serial8250_register_8250_port() instead uses UART line number 0, which is stored in data->line. On driver unbind, bcm2835aux_serial_remove() uses data->uart.port.line, which contains the wrong number. Fix it. The issue does not occur if the maximum number of 8250 UARTs is >= 2. Fixes: bdc5f3009580 ("serial: bcm2835: add driver for bcm2835-aux-uart") Signed-off-by: Lukas Wunner <lukas@wunner.de> Cc: stable@vger.kernel.org # v4.6+ Cc: Martin Sperl <kernel@martin.sperl.org> Reviewed-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> Tested-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> Link: https://lore.kernel.org/r/912ccf553c5258135c6d7e8f404a101ef320f0f4.1579175223.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-04tty: Remove dev_err() usage after platform_get_irq()Stephen Boyd
We don't need dev_err() messages when platform_get_irq() fails now that platform_get_irq() prints an error message itself when something goes wrong. Let's remove these prints with a simple semantic patch. // <smpl> @@ expression ret; struct platform_device *E; @@ ret = ( platform_get_irq(E, ...) | platform_get_irq_byname(E, ...) ); if ( \( ret < 0 \| ret <= 0 \) ) { ( -if (ret != -EPROBE_DEFER) -{ ... -dev_err(...); -... } | ... -dev_err(...); ) ... } // </smpl> While we're here, remove braces on if statements that only have one statement (manually). Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Stephen Boyd <swboyd@chromium.org> Link: https://lore.kernel.org/r/20190730181557.90391-45-swboyd@chromium.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-08tty: serial: Remove redundant license textGreg Kroah-Hartman
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 <jslaby@suse.com> Cc: Eric Anholt <eric@anholt.net> Cc: Stefan Wahren <stefan.wahren@i2se.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: Ray Jui <rjui@broadcom.com> Cc: Scott Branden <sbranden@broadcom.com> Cc: bcm-kernel-feedback-list@broadcom.com Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Cc: Joachim Eastwood <manabian@gmail.com> Cc: Matthias Brugger <matthias.bgg@gmail.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Tobias Klauser <tklauser@distanz.ch> Cc: Russell King <linux@armlinux.org.uk> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Richard Genoud <richard.genoud@gmail.com> Cc: Alexander Shiyan <shc_work@mail.ru> Cc: Baruch Siach <baruch@tkos.co.il> Cc: Pat Gefre <pfg@sgi.com> Cc: "Guilherme G. Piccoli" <gpiccoli@linux.vnet.ibm.com> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Vladimir Zapolskiy <vz@mleia.com> Cc: Sylvain Lemieux <slemieux.tyco@gmail.com> Cc: Carlo Caione <carlo@caione.org> Cc: Kevin Hilman <khilman@baylibre.com> Cc: Liviu Dudau <liviu.dudau@arm.com> Cc: Sudeep Holla <sudeep.holla@arm.com> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: Andy Gross <andy.gross@linaro.org> Cc: David Brown <david.brown@linaro.org> Cc: "Andreas Färber" <afaerber@suse.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Kevin Cernekee <cernekee@gmail.com> Cc: Laxman Dewangan <ldewangan@nvidia.com> Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Jonathan Hunter <jonathanh@nvidia.com> Cc: Barry Song <baohua@kernel.org> Cc: Patrice Chotard <patrice.chotard@st.com> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> Cc: Alexandre Torgue <alexandre.torgue@st.com> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Peter Korsgaard <jacmet@sunsite.dk> Cc: Timur Tabi <timur@tabi.org> Cc: Tony Prisk <linux@prisktech.co.nz> Cc: Michal Simek <michal.simek@xilinx.com> Cc: "Sören Brinkmann" <soren.brinkmann@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-08tty: add SPDX identifiers to all remaining files in drivers/tty/Greg Kroah-Hartman
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 <jslaby@suse.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: David Sterba <dsterba@suse.com> Cc: James Hogan <jhogan@kernel.org> Cc: Rob Herring <robh@kernel.org> Cc: Eric Anholt <eric@anholt.net> Cc: Stefan Wahren <stefan.wahren@i2se.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: Ray Jui <rjui@broadcom.com> Cc: Scott Branden <sbranden@broadcom.com> Cc: bcm-kernel-feedback-list@broadcom.com Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Cc: Joachim Eastwood <manabian@gmail.com> Cc: Matthias Brugger <matthias.bgg@gmail.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Tobias Klauser <tklauser@distanz.ch> Cc: Russell King <linux@armlinux.org.uk> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Richard Genoud <richard.genoud@gmail.com> Cc: Alexander Shiyan <shc_work@mail.ru> Cc: Baruch Siach <baruch@tkos.co.il> Cc: "Maciej W. Rozycki" <macro@linux-mips.org> Cc: "Uwe Kleine-König" <kernel@pengutronix.de> Cc: Pat Gefre <pfg@sgi.com> Cc: "Guilherme G. Piccoli" <gpiccoli@linux.vnet.ibm.com> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Vladimir Zapolskiy <vz@mleia.com> Cc: Sylvain Lemieux <slemieux.tyco@gmail.com> Cc: Carlo Caione <carlo@caione.org> Cc: Kevin Hilman <khilman@baylibre.com> Cc: Liviu Dudau <liviu.dudau@arm.com> Cc: Sudeep Holla <sudeep.holla@arm.com> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: Andy Gross <andy.gross@linaro.org> Cc: David Brown <david.brown@linaro.org> Cc: "Andreas Färber" <afaerber@suse.de> Cc: Kevin Cernekee <cernekee@gmail.com> Cc: Laxman Dewangan <ldewangan@nvidia.com> Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Jonathan Hunter <jonathanh@nvidia.com> Cc: Barry Song <baohua@kernel.org> Cc: Patrice Chotard <patrice.chotard@st.com> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> Cc: Alexandre Torgue <alexandre.torgue@st.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Peter Korsgaard <jacmet@sunsite.dk> Cc: Timur Tabi <timur@tabi.org> Cc: Tony Prisk <linux@prisktech.co.nz> Cc: Michal Simek <michal.simek@xilinx.com> Cc: "Sören Brinkmann" <soren.brinkmann@xilinx.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: Philippe Ombredanne <pombredanne@nexb.com> Cc: Jiri Slaby <jslaby@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-24serial: 8250: Add CAP_MINI, set for bcm2835auxPhil Elwell
The AUX/mini-UART in the BCM2835 family of procesors is a cut-down 8250 clone. In particular it is lacking support for the following features: CSTOPB PARENB PARODD CMSPAR CS5 CS6 Add a new capability (UART_CAP_MINI) that exposes the restrictions to the user of the termios API by turning off the unsupported features in the request. N.B. It is almost possible to automatically discover the missing features by reading back the LCR register, but the CSIZE bits don't cooperate (contrary to the documentation, both bits are significant, but CS5 and CS6 are mapped to CS7) and the code is much longer. See: https://github.com/raspberrypi/linux/issues/1561 Signed-off-by: Phil Elwell <phil@raspberrypi.org> Acked-by: Eric Anholt <eric@anholt.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-14serial: bcm2835: fix unsigned int issue with irqMartin Sperl
Fixes error condition check when requesting the irq, that would not trigger because of uart_port.irq being defined as unsigned int. Reported by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Martin Sperl <kernel@martin.sperl.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06serial: bcm2835: add driver for bcm2835-aux-uartMartin Sperl
The bcm2835 SOC contains an auxiliary uart, which is very close to the ns16550 with some differences. The big difference is that the uart HW is not using an internal divider of 16 but 8, which results in an effictive baud-rate being twice the requested baud-rate. This driver handles this device correctly and handles the difference in the HW divider by scaling up the clock by a factor of 2. The approach to write a separate (wrapper) driver instead of using a multiplying clock and "ns16550" as compatibility in the device-tree has been recommended by Stephen Warren. Signed-off-by: Martin Sperl <kernel@martin.sperl.org> Acked-by: Eric Anholt <eric@anholt.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>