linux/arch/arm/include/debug/renesas-scif.S

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/* SPDX-License-Identifier: GPL-2.0 */
ARM: shmobile: Add early debugging support using SCIF(A) Add serial port debug macros for the SCIF(A) serial ports. This includes all supported shmobile SoCs, except for EMEV2. The configuration logic (both Kconfig and #ifdef) is more complicated than one would expect, for several reasons: 1. Not all SoCs have the same serial devices, and they're not always at the same addresses. 2. There are two different types: SCIF and SCIFA. Fortunately they can easily be distinguished by physical address. 3. Not all boards use the same serial port for the console. The defaults correspond to the boards that are supported in mainline. If you want to use a different serial port, just change the value of CONFIG_DEBUG_UART_PHYS, and the rest will auto-adapt. 4. debug_ll_io_init() maps the SCIF(A) registers to a fixed virtual address. 0xfdxxxxxx was chosen, as it should lie below VMALLOC_END = 0xff000000, and must not conflict with the 2 MiB reserved region at PCI_IO_VIRT_BASE = 0xfee00000. - On SoCs not using the legacy machine_desc.map_io(), debug_ll_io_init() is called by the ARM core code. - On SoCs using the legacy machine_desc.map_io(), debug_ll_io_init() must be called explicitly. Calls are added for r8a7740, r8a7779, sh7372, and sh73a0. This was derived from the r8a7790 version by Laurent Pinchart. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Tested-by: Simon Horman <horms+renesas@verge.net.au> Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
2014-11-14 16:49:47 +01:00
/*
* Renesas SCIF(A) debugging macro include header
*
* Based on r8a7790.S
*
* Copyright (C) 2012-2013 Renesas Electronics Corporation
* Copyright (C) 1994-1999 Russell King
*/
#define SCIF_PHYS CONFIG_DEBUG_UART_PHYS
#define SCIF_VIRT ((SCIF_PHYS & 0x00ffffff) | 0xfd000000)
#if defined(CONFIG_DEBUG_R7S9210_SCIF2) || defined(CONFIG_DEBUG_R7S9210_SCIF4)
/* RZ/A2 SCIFA */
#define FTDR 0x06
#define FSR 0x08
#elif CONFIG_DEBUG_UART_PHYS < 0xe6e00000
ARM: shmobile: Add early debugging support using SCIF(A) Add serial port debug macros for the SCIF(A) serial ports. This includes all supported shmobile SoCs, except for EMEV2. The configuration logic (both Kconfig and #ifdef) is more complicated than one would expect, for several reasons: 1. Not all SoCs have the same serial devices, and they're not always at the same addresses. 2. There are two different types: SCIF and SCIFA. Fortunately they can easily be distinguished by physical address. 3. Not all boards use the same serial port for the console. The defaults correspond to the boards that are supported in mainline. If you want to use a different serial port, just change the value of CONFIG_DEBUG_UART_PHYS, and the rest will auto-adapt. 4. debug_ll_io_init() maps the SCIF(A) registers to a fixed virtual address. 0xfdxxxxxx was chosen, as it should lie below VMALLOC_END = 0xff000000, and must not conflict with the 2 MiB reserved region at PCI_IO_VIRT_BASE = 0xfee00000. - On SoCs not using the legacy machine_desc.map_io(), debug_ll_io_init() is called by the ARM core code. - On SoCs using the legacy machine_desc.map_io(), debug_ll_io_init() must be called explicitly. Calls are added for r8a7740, r8a7779, sh7372, and sh73a0. This was derived from the r8a7790 version by Laurent Pinchart. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Tested-by: Simon Horman <horms+renesas@verge.net.au> Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
2014-11-14 16:49:47 +01:00
/* SCIFA */
#define FTDR 0x20
#define FSR 0x14
#else
/* SCIF */
#define FTDR 0x0c
#define FSR 0x10
#endif
#define TDFE (1 << 5)
#define TEND (1 << 6)
.macro addruart, rp, rv, tmp
ldr \rp, =SCIF_PHYS
ldr \rv, =SCIF_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>
2020-08-27 23:25:37 +01:00
.macro waituartcts,rd,rx
.endm
.macro waituarttxrdy, rd, rx
ARM: shmobile: Add early debugging support using SCIF(A) Add serial port debug macros for the SCIF(A) serial ports. This includes all supported shmobile SoCs, except for EMEV2. The configuration logic (both Kconfig and #ifdef) is more complicated than one would expect, for several reasons: 1. Not all SoCs have the same serial devices, and they're not always at the same addresses. 2. There are two different types: SCIF and SCIFA. Fortunately they can easily be distinguished by physical address. 3. Not all boards use the same serial port for the console. The defaults correspond to the boards that are supported in mainline. If you want to use a different serial port, just change the value of CONFIG_DEBUG_UART_PHYS, and the rest will auto-adapt. 4. debug_ll_io_init() maps the SCIF(A) registers to a fixed virtual address. 0xfdxxxxxx was chosen, as it should lie below VMALLOC_END = 0xff000000, and must not conflict with the 2 MiB reserved region at PCI_IO_VIRT_BASE = 0xfee00000. - On SoCs not using the legacy machine_desc.map_io(), debug_ll_io_init() is called by the ARM core code. - On SoCs using the legacy machine_desc.map_io(), debug_ll_io_init() must be called explicitly. Calls are added for r8a7740, r8a7779, sh7372, and sh73a0. This was derived from the r8a7790 version by Laurent Pinchart. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Tested-by: Simon Horman <horms+renesas@verge.net.au> Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
2014-11-14 16:49:47 +01:00
1001: ldrh \rd, [\rx, #FSR]
tst \rd, #TDFE
beq 1001b
.endm
.macro senduart, rd, rx
strb \rd, [\rx, #FTDR]
ldrh \rd, [\rx, #FSR]
bic \rd, \rd, #TEND
strh \rd, [\rx, #FSR]
.endm
.macro busyuart, rd, rx
1001: ldrh \rd, [\rx, #FSR]
tst \rd, #TEND
beq 1001b
.endm