[U-Boot] [PATCH 4/4] armv8/ls1043aqds: Initizlize NS16550 if enalbed LPUART

[Wenbin Song]

Hi:Bin
Thanks for your advice! I realize that I can use the lpuart as earlycon on kernel . So I will remove this patch on next vesion.

Thanks 

Wenbin Song 

Sent from my iPhone

> On Jan 19, 2016, at 18:42, Bin Meng <bmeng.cn at gmail.com> wrote:
> 
> Hi Wenbin,
> 
>> On Tue, Jan 19, 2016 at 6:21 PM, Wenbin Song <wenbin.song at nxp.com> wrote:
>> 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 "
> 
> I understand this. My question was: U-Boot was booted using LPUART as
> its serial console, why do you bother loading a kernel with another
> serial port as the early console?
> 
>> 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;
>> }
> 
> [snip]
> 
> Regards,
> Bin