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acrn-kernel/arch/arm/include/debug/asm9260.S

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treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 Based on 2 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation # extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4122 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Enrico Weigelt <info@metux.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-04 16:11:33 +08:00
/* SPDX-License-Identifier: GPL-2.0-only */
ARM: add lolevel debug support for asm9260 Since there is no public documentation, this patch also provide register offsets for different UART units on this SoC. Signed-off-by: Oleksij Rempel <linux@rempel-privat.de> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2014-11-24 19:08:28 +08:00
/* Debugging macro include header
*
* Copyright (C) 1994-1999 Russell King
* Moved from linux/arch/arm/kernel/debug.S by Ben Dooks
* Modified for ASM9260 by Oleksij Remepl <linux@rempel-privat.de>
*/
.macro addruart, rp, rv, tmp
ldr \rp, = CONFIG_DEBUG_UART_PHYS
ldr \rv, = CONFIG_DEBUG_UART_VIRT
.endm
ARM: 9004/1: debug: Split waituart to CTS and TXRDY This patch was triggered by a remark from Russell that introducing a call to the waituart (needed to fix debug prints on the Qualcomm platforms) was dangerous because in some cases this will involve waiting for a modem CTS (clear to send) signal, and debug messages would maybe not work on platforms with no modem connected to the UART port: they will just hang waiting for the modem to assert CTS and this might never happen. Looking through all UART debug drivers implementing the waituart macro I discovered that all users except two actually use this macro to check if the UART is ready for TX, let's call this TXRDY. Only two debug UART drivers actually check for CTS: - arch/arm/include/debug/8250.S - arch/arm/include/debug/tegra.S The former is very significant since the 8250 is possibly the most common UART on the planet. We have the following problem: the semantics of waituart are ambiguous making it dangerous to introduce the macro to debug code fixing debug prints for Qualcomm. To start to pry this problem apart, this patch does the following: - Convert all debug UART drivers to define two macros: - waituartcts with the clear semantic to wait for CTS to be asserted - waituarttxrdy with the clear semantic to wait for the TX capability of the UART to be ready - When doing this take care to assign the right function to each drivers macro, so they now do exactly the above. - Update the three sites in the kernel invoking the waituart macro to call waituartcts/waituarttxrdy in sequence, so that the functional impact on the kernel should be zero. After this we can start to change the code sites using this code to do the right thing. Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2020-08-28 06:25:37 +08:00
.macro waituarttxrdy,rd,rx
.endm
.macro waituartcts,rd,rx
ARM: add lolevel debug support for asm9260 Since there is no public documentation, this patch also provide register offsets for different UART units on this SoC. Signed-off-by: Oleksij Rempel <linux@rempel-privat.de> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2014-11-24 19:08:28 +08:00
.endm
.macro senduart,rd,rx
str \rd, [\rx, #0x50] @ TXDATA
.endm
.macro busyuart,rd,rx
1002: ldr \rd, [\rx, #0x60] @ STAT
tst \rd, #1 << 27 @ TXEMPTY
beq 1002b @ wait until transmit done
.endm