Hi: Bin, Because we use the ns16550 as the early console when booting kernel , and the earlycon driver on kernel cannot initialize port->uartclk rightly, So if we want to use it, we must initialize ns16550 on uboot, and use the bootargs as follow : "console=ttyS0,115200 root=/dev/ram0 earlycon=uart8250,0x21c0500 "
int __init early_serial8250_setup(struct earlycon_device *device, const char *options) { if (!(device->port.membase || device->port.iobase)) return -ENODEV;
if (!device->baud) { struct uart_port *port = &device->port; unsigned int ier;
/* assume the device was initialized, only mask interrupts */ ier = serial8250_early_in(port, UART_IER); serial8250_early_out(port, UART_IER, ier & UART_IER_UUE); } else init_port(device);
device->con->write = early_serial8250_write; return 0; }
Regards
Wenbin Song
-----Original Message----- From: Bin Meng [mailto:bmeng.cn@gmail.com] Sent: Tuesday, January 19, 2016 4:08 PM To: Wenbin Song wenbin.song@nxp.com Cc: York Sun yorksun@freescale.com; Mingkai Hu mingkai.hu@nxp.com; Qianyu Gong qianyu.gong@nxp.com; Shaohui Xie shaohui.xie@nxp.com; U-Boot Mailing List u-boot@lists.denx.de; Wenbin Song Wenbin.Song@freescale.com Subject: Re: [U-Boot] [PATCH 4/4] armv8/ls1043aqds: Initizlize NS16550 if enalbed LPUART
Hi Wenbin,
On Tue, Jan 19, 2016 at 2:48 PM, Wenbin Song wenbin.song@nxp.com wrote:
From: Wenbin Song Wenbin.Song@freescale.com
Need to initialize ns16550 to support earlycon on kernel.
Signed-off-by: Wenbin Song Wenbin.Song@freescale.com Signed-off-by: Mingkai Hu Mingkai.Hu@freescale.com
board/freescale/ls1043aqds/ls1043aqds.c | 12 ++++++++++++ configs/ls1043aqds_lpuart_defconfig | 1 + include/configs/ls1043aqds.h | 3 ++- 3 files changed, 15 insertions(+), 1 deletion(-)
diff --git a/board/freescale/ls1043aqds/ls1043aqds.c b/board/freescale/ls1043aqds/ls1043aqds.c index 1da3fe1..fcbd95c 100644 --- a/board/freescale/ls1043aqds/ls1043aqds.c +++ b/board/freescale/ls1043aqds/ls1043aqds.c @@ -21,6 +21,7 @@ #include <fsl_esdhc.h> #include <fsl_ifc.h> #include <spl.h> +#include <ns16550.h>
#include "../common/qixis.h" #include "ls1043aqds_qixis.h" @@ -219,6 +220,17 @@ void board_retimer_init(void) i2c_write(I2C_RETIMER_ADDR, 0x64, 1, ®, 1); }
+int board_early_init_r(void) +{ +#ifdef CONFIG_LPUART
- /* Initialize ns16500 for earlycon on kernel.*/
NS16550_init((NS16550_t)CONFIG_SYS_NS16550_COM1,DIV_ROUND_CLOSEST(CONFIG_SYS_NS16550_CLK,16 * CONFIG_BAUDRATE)); #endif
This change does not make a lot sense to me. Since U-Boot is using LPUART as its system console, why do you want to load a kernel that uses the NS16550 as the system console? IMHO we should ask kernel to use LPUART as well, IOW keep in sync with the underlying bootloader.
return 0;+}
int board_early_init_f(void) { #ifdef CONFIG_LPUART diff --git a/configs/ls1043aqds_lpuart_defconfig b/configs/ls1043aqds_lpuart_defconfig index ca06abe..26f7b36 100644 --- a/configs/ls1043aqds_lpuart_defconfig +++ b/configs/ls1043aqds_lpuart_defconfig @@ -1,6 +1,7 @@ CONFIG_SYS_EXTRA_OPTIONS="SYS_FSL_DDR4,LPUART" CONFIG_ARM=y CONFIG_TARGET_LS1043AQDS=y +CONFIG_SYS_NS16550=y CONFIG_DEFAULT_DEVICE_TREE="fsl-ls1043a-qds" CONFIG_OF_CONTROL=y CONFIG_DM=y diff --git a/include/configs/ls1043aqds.h b/include/configs/ls1043aqds.h index 88f4bc0..d66d8f9 100644 --- a/include/configs/ls1043aqds.h +++ b/include/configs/ls1043aqds.h @@ -30,6 +30,8 @@ unsigned long get_board_ddr_clk(void);
#define CONFIG_LAYERSCAPE_NS_ACCESS
+#define CONFIG_BOARD_EARLY_INIT_R
#define CONFIG_DIMM_SLOTS_PER_CTLR 1 /* Physical Memory Map */ #define CONFIG_CHIP_SELECTS_PER_CTRL 4 @@ -96,7 +98,6 @@ unsigned long get_board_ddr_clk(void); #define CONFIG_LPUART_32B_REG #undef CONFIG_CONS_INDEX #undef CONFIG_SYS_NS16550_SERIAL -#undef CONFIG_SYS_NS16550_CLK #endif
/* SATA */
Regards, Bin