From e7aa6f46f6e4644d466e04f54b5750a91d188abf Mon Sep 17 00:00:00 2001 From: Ben Dooks Date: Tue, 2 Dec 2008 19:34:52 +0000 Subject: [PATCH] [ARM] S3C: Add UART FIFO selection during arch decompression Add a configuration option to start the UART FIFOs during the decompressions sequence to improve boot time when the bootloader fails to enable the UART FIFOs. For example, the SMDK6410 UBoot 1.1.6 leaves the FIFOs off. Signed-off-by: Ben Dooks --- arch/arm/plat-s3c/Kconfig | 8 ++++++++ arch/arm/plat-s3c/include/plat/uncompress.h | 28 ++++++++++++++++++++++++++++ 2 files changed, 36 insertions(+) diff --git a/arch/arm/plat-s3c/Kconfig b/arch/arm/plat-s3c/Kconfig index 31656c3..10c1dd3 100644 --- a/arch/arm/plat-s3c/Kconfig +++ b/arch/arm/plat-s3c/Kconfig @@ -57,6 +57,14 @@ config S3C_BOOT_ERROR_RESET Say y here to use the watchdog to reset the system if the kernel decompressor detects an error during decompression. +config S3C_BOOT_UART_FORCE_FIFO + bool "Force UART FIFO on during boot process" + depends on PLAT_S3C + default y + help + Say Y here to force the UART FIFOs on during the kernel + uncompressor + comment "Power management" config S3C2410_PM_DEBUG diff --git a/arch/arm/plat-s3c/include/plat/uncompress.h b/arch/arm/plat-s3c/include/plat/uncompress.h index 8a8a927..2c39a30 100644 --- a/arch/arm/plat-s3c/include/plat/uncompress.h +++ b/arch/arm/plat-s3c/include/plat/uncompress.h @@ -139,6 +139,28 @@ static void arch_decomp_error(const char *x) static void error(char *err); +#ifdef CONFIG_S3C_BOOT_UART_FORCE_FIFO +static inline void arch_enable_uart_fifo(void) +{ + u32 fifocon = uart_rd(S3C2410_UFCON); + + if (!(fifocon & S3C2410_UFCON_FIFOMODE)) { + fifocon |= S3C2410_UFCON_RESETBOTH; + uart_wr(S3C2410_UFCON, fifocon); + + /* wait for fifo reset to complete */ + while (1) { + fifocon = uart_rd(S3C2410_UFCON); + if (!(fifocon & S3C2410_UFCON_RESETBOTH)) + break; + } + } +} +#else +#define arch_enable_uart_fifo() do { } while(0) +#endif + + static void arch_decomp_setup(void) { @@ -149,6 +171,12 @@ arch_decomp_setup(void) arch_detect_cpu(); arch_decomp_wdog_start(); + + /* Enable the UART FIFOs if they where not enabled and our + * configuration says we should turn them on. + */ + + arch_enable_uart_fifo(); } -- 2.7.4