* Kevin Hilman <[email protected]> [090822 16:31]:
> Vikram Pandita wrote:
>> This patch cleans up the DEBUG_LL infrastructure for omap boards.
>
> Thanks Vikram, this is indeed in need of some cleanup. But I have some
> comments about the approach taken.
>
> This approach still doesn't solve one of the fundamental problems with
> the current implementation. It prevents using a single kernel across
> multiple boards. If we could drop the compile-time decision in favor of
> a runtime one based on machine-type, we could use a single base
> defconfig that would be able to be tested on all omap3 boards for example.
>
> For the zImage UART output (uncompress.h) there is a global variable
> __machine_arch_type which could be used to check the board type and set
> variable for UART base and shift. We do this on DaVinci.
I agree we should do this.
> For debug output (debug-macro.S) those macros should be changed to use
> variables for UART base and shift also. While you're in changing the
> board files, you could also add something like this to each:
>
> #ifdef CONFIG_SERIAL_8250_CONSOLE
> static int __init board_console_init(void)
> {
> return add_preferred_console("ttyS", <UART#>, "115200");
> }
> console_initcall(board_console_init);
> #endif
>
> This also allows the board to boot using a default UART even without
> having the console= on the cmdline.
>
> There is one catch to doing this at runtime instead of compile time.
> The variables for the UART base and shift have to be set very early in
> the boot, otherwise any errors from the early ARM asm boot (head.S) will
> be missed.
>
> For starters, they could be assingned in the board map_io hook, but we'd
> still miss the debug prints if there were any errors parsing the
> machine_type and processor_type early in the boot (head.S)
>
> I'd be ok with this limitation for a first pass because it's still
> better than what we currently have in l-o, but I'd like to hear if
> others had some ideas for how we might do dynamic decisions on UART
> based on board-type very early in the boot.
Yup, good comments.
Tony
>
> Kevin
>
>> The three stages of log printing infrastructure is using their own #defines
>> The patch integrates the three stages to use the same variable.
>>
>> Three stages are:
>> Stage 1: Prints - Uncompressing Linux......
>> File getting used: arch/arm/plat-omap/include/mach/uncompress.h
>> Stage 2: Prints - <5>Linux version 2.6.31
>> File getting used: arch/arm/plat-omap/include/mach/debug-macro.S
>> Stage 3: Kernel ttyS console takes over
>>
>> On enabling the DEBUG_LL menuconfig item
>> [Kernel Hacking -> Kernel low-level debugging functions]
>>
>> the following entry gets auto selected
>> [Systerm Type -> TI OMAP Implementations -> Low-level Debug console UART]
>>
>> This is the physical address of the UART getting used for the board.
>> The physical address of debug uart is provided as a menuconfig option now.
>>
>> Issue with current system:
>> (a) Zoom2 board has a detachable debug board having the TL16CP754 Quad uart
>> chip.
>> If the debug board is not attached, _NO_ debug uart is available.
>> OMAP internal uarts are not used for traces on zoom2 board.
>> Current framework does not account for boards that may not have a debug uart
>> at all. The Stage 1 always accesses one of the uarts. Thats fixed now.
>>
>> (b) this patch does a cleanup of
>> arch/arm/plat-omap/include/mach/debug-macro.S
>>
>> Signed-off-by: Vikram Pandita <[email protected]>
>> ---
>> arch/arm/plat-omap/Kconfig | 50
>> ++++++++++++++++++-------
>> arch/arm/plat-omap/include/mach/common.h | 7 +++
>> arch/arm/plat-omap/include/mach/debug-macro.S | 40 ++++----------------
>> arch/arm/plat-omap/include/mach/uncompress.h | 12 +----
>> 4 files changed, 54 insertions(+), 55 deletions(-)
>>
>> diff --git a/arch/arm/plat-omap/Kconfig b/arch/arm/plat-omap/Kconfig
>> index ab9f9ef..2fefb64 100644
>> --- a/arch/arm/plat-omap/Kconfig
>> +++ b/arch/arm/plat-omap/Kconfig
>> @@ -162,21 +162,43 @@ config OMAP_DM_TIMER
>> help
>> Select this option if you want to use OMAP Dual-Mode timers.
>> -choice
>> - prompt "Low-level debug console UART"
>> - depends on ARCH_OMAP
>> - default OMAP_LL_DEBUG_UART1
>> -
>> -config OMAP_LL_DEBUG_UART1
>> - bool "UART1"
>> -
>> -config OMAP_LL_DEBUG_UART2
>> - bool "UART2"
>> -config OMAP_LL_DEBUG_UART3
>> - bool "UART3"
>> -
>> -endchoice
>> +config OMAP_DEBUG_LL_UART_PHY_ADDR
>> + hex "Low-level debug console UART Physical Address"
>> + depends on ARCH_OMAP && DEBUG_LL
>> +
>> + default "0xfffb0800" if ARCH_OMAP1 && (MACH_OMAP_PALMTT || MACH_SX1)
>> + default "0xfffb0000" if ARCH_OMAP1
>> + default "0x4806e000" if ARCH_OMAP2 && MACH_NOKIA_N8X0
>> + default "0x4806a000" if ARCH_OMAP2
>> + default "0x49020000" if ARCH_OMAP3 && (MACH_NOKIA_RX51 ||
>> MACH_OMAP_BEAGLE)
>> + default "0x49020000" if ARCH_OMAP3 && (MACH_OMAP3_PANDORA ||
>> MACH_OMAP_LDP || MACH_OVERO)
>> + default "0x10000000" if ARCH_OMAP3 && MACH_OMAP_ZOOM2
>> + default "0x4806a000" if ARCH_OMAP3
>> + default "0x4806a000" if ARCH_OMAP4
>> + help
>> + Specify the Physical address of Low level debug UART
>> + Specify 0x0 in case you do not want DEBUG_LL functions to iterfere
>> with your board uarts
>> +
>> + OMAP1:
>> + -------------------
>> + UART1 -> 0xfffb0000 (default)
>> + UART2 -> 0xfffb0800
>> + UART3 -> 0xfffb9800 (sx1, palmtt)
>> +
>> + OMAP2:
>> + -------------------
>> + UART1 -> 0x4806a000 (default)
>> + UART2 -> 0x4806c000
>> + UART3 -> 0x4806e000 (N8X0)
>> +
>> + OMAP3/4:
>> + -------------------
>> + UART1 -> 0x4806a000 (default: except following)
>> + UART2 -> 0x4806c000
>> + UART3 -> 0x49020000 (rx51, beagle, pendora, ldp, overo)
>> + UART4 -> 0x4806e000
>> + UART_EXT -> 0x10000000 (zoom2: Debug uart is on external debug
>> board)
>> config OMAP_SERIAL_WAKE
>> bool "Enable wake-up events for serial ports"
>> diff --git a/arch/arm/plat-omap/include/mach/common.h
>> b/arch/arm/plat-omap/include/mach/common.h
>> index fdeab42..f29d31f 100644
>> --- a/arch/arm/plat-omap/include/mach/common.h
>> +++ b/arch/arm/plat-omap/include/mach/common.h
>> @@ -68,4 +68,11 @@ void omap2_set_globals_sdrc(struct omap_globals *);
>> void omap2_set_globals_control(struct omap_globals *);
>> void omap2_set_globals_prcm(struct omap_globals *);
>> +/* In case Low Level debug is not defined
>> + * make the low level uart address as zero
>> + */
>> +#if !defined(CONFIG_DEBUG_LL)
>> +#define CONFIG_OMAP_DEBUG_LL_UART_PHY_ADDR 0
>> +#endif
>> +
>> #endif /* __ARCH_ARM_MACH_OMAP_COMMON_H */
>> diff --git a/arch/arm/plat-omap/include/mach/debug-macro.S
>> b/arch/arm/plat-omap/include/mach/debug-macro.S
>> index ac24050..f546d6c 100644
>> --- a/arch/arm/plat-omap/include/mach/debug-macro.S
>> +++ b/arch/arm/plat-omap/include/mach/debug-macro.S
>> @@ -10,43 +10,19 @@
>> * published by the Free Software Foundation.
>> *
>> */
>> +#include "io.h"
>> .macro addruart,rx
>> mrc p15, 0, \rx, c1, c0
>> tst \rx, #1 @ MMU enabled?
>> #ifdef CONFIG_ARCH_OMAP1
>> - moveq \rx, #0xff000000 @ physical base address
>> - movne \rx, #0xfe000000 @ virtual base
>> - orr \rx, \rx, #0x00fb0000
>> -#ifdef CONFIG_OMAP_LL_DEBUG_UART3
>> - orr \rx, \rx, #0x00009000 @ UART 3
>> -#endif
>> -#if defined(CONFIG_OMAP_LL_DEBUG_UART2) ||
>> defined(CONFIG_OMAP_LL_DEBUG_UART3)
>> - orr \rx, \rx, #0x00000800 @ UART 2 & 3
>> -#endif
>> -
>> -#elif CONFIG_ARCH_OMAP2
>> - moveq \rx, #0x48000000 @ physical base address
>> - movne \rx, #0xd8000000 @ virtual base
>> - orr \rx, \rx, #0x0006a000
>> -#ifdef CONFIG_OMAP_LL_DEBUG_UART2
>> - add \rx, \rx, #0x00002000 @ UART 2
>> -#endif
>> -#ifdef CONFIG_OMAP_LL_DEBUG_UART3
>> - add \rx, \rx, #0x00004000 @ UART 3
>> -#endif
>> -
>> -#elif defined(CONFIG_ARCH_OMAP3) || defined(CONFIG_ARCH_OMAP4)
>> - moveq \rx, #0x48000000 @ physical base address
>> - movne \rx, #0xd8000000 @ virtual base
>> - orr \rx, \rx, #0x0006a000
>> -#ifdef CONFIG_OMAP_LL_DEBUG_UART2
>> - add \rx, \rx, #0x00002000 @ UART 2
>> -#endif
>> -#ifdef CONFIG_OMAP_LL_DEBUG_UART3
>> - add \rx, \rx, #0x00fb0000 @ UART 3
>> - add \rx, \rx, #0x00006000
>> -#endif
>> + /* omap1 */
>> + ldr \rx, =CONFIG_OMAP_DEBUG_LL_UART_PHY_ADDR @ physical
>> base address
>> + subne \rx, #CONFIG_OMAP_DEBUG_LL_UART_PHY_ADDR,
>> #OMAP1_IO_OFFSET @ virtual base
>> +#else
>> + /* omap2/omap3/omap4 */
>> + ldr \rx, =CONFIG_OMAP_DEBUG_LL_UART_PHY_ADDR @ physical
>> base address
>> + orrne \rx, \rx, #OMAP2_IO_OFFSET @ virtual base
>> #endif
>> .endm
>> diff --git a/arch/arm/plat-omap/include/mach/uncompress.h
>> b/arch/arm/plat-omap/include/mach/uncompress.h
>> index 0814c5f..0e21eb3 100644
>> --- a/arch/arm/plat-omap/include/mach/uncompress.h
>> +++ b/arch/arm/plat-omap/include/mach/uncompress.h
>> @@ -38,14 +38,8 @@ static void putc(int c)
>> return;
>> #endif
>> -#ifdef CONFIG_ARCH_OMAP
>> -#ifdef CONFIG_OMAP_LL_DEBUG_UART3
>> - uart = (volatile u8 *)(OMAP_UART3_BASE);
>> -#elif defined(CONFIG_OMAP_LL_DEBUG_UART2)
>> - uart = (volatile u8 *)(OMAP_UART2_BASE);
>> -#else
>> - uart = (volatile u8 *)(OMAP_UART1_BASE);
>> -#endif
>> +#if defined(CONFIG_DEBUG_LL)
>> + uart = (volatile u8 *)(CONFIG_OMAP_DEBUG_LL_UART_PHY_ADDR);
>> #ifdef CONFIG_ARCH_OMAP1
>> /* Determine which serial port to use */
>> @@ -62,7 +56,6 @@ static void putc(int c)
>> return;
>> } while (0);
>> #endif /* CONFIG_ARCH_OMAP1 */
>> -#endif
>> /*
>> * Now, xmit each character
>> @@ -70,6 +63,7 @@ static void putc(int c)
>> while (!(uart[UART_LSR << shift] & UART_LSR_THRE))
>> barrier();
>> uart[UART_TX << shift] = c;
>> +#endif /* CONFIG_DEBUG_LL */
>> }
>> static inline void flush(void)
>
>
>
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