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Re: [PATCH 8/8] 8250: add Texas Instruments AR7 internal UART

To: linux-mips@linux-mips.org
Subject: Re: [PATCH 8/8] 8250: add Texas Instruments AR7 internal UART
From: Alexander Clouter <alex@digriz.org.uk>
Date: Thu, 11 Jun 2009 12:27:19 +0100
Cc: linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org
Original-recipient: rfc822;linux-mips@linux-mips.org
References: <200906041622.47591.florian@openwrt.org> <20090604222020.GA14843@alpha.franken.de> <200906111028.41222.florian@openwrt.org> <20090611093022.GA14510@alpha.franken.de>
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In gmane.linux.ports.mips.general Thomas Bogendoerfer 
<tsbogend@alpha.franken.de> wrote:
>
> On Thu, Jun 11, 2009 at 10:28:39AM +0200, Florian Fainelli wrote:
>> Le Friday 05 June 2009 00:20:20 Thomas Bogendoerfer, vous avez écrit :
>> > On Thu, Jun 04, 2009 at 04:22:46PM +0200, Florian Fainelli wrote:
>> > > We discussed that in private, there are a couple of things
>> > > to fix in order to get 8250 working properly with TI AR7 HW.
>> > > If you can still merge that bit, this would ease future work, thanks !
>> >
>> > I still have a tree here, which works without any changes to the 8250
>> > serial driver on a TNETD7300 device.
>> 
>> Could you show me how you register the 8250 driver ? Without the 
>> 8250-specific 
> 
> static struct plat_serial8250_port uart0_data = {
>        .mapbase = AR7_REGS_UART0,
>        .irq = AR7_IRQ_UART0,
>        .regshift = 2,
>        .iotype = UPIO_MEM,
>        .flags = UPF_BOOT_AUTOCONF | UPF_IOREMAP,
> };
> 
>        uart_port[0].type = PORT_16550A;
>        uart_port[0].line = 0;
>        uart_port[0].irq = AR7_IRQ_UART0;
>        uart_port[0].uartclk = ar7_bus_freq() / 2;
>        uart_port[0].iotype = UPIO_MEM;
>        uart_port[0].mapbase = AR7_REGS_UART0 + 3;
>        uart_port[0].membase = ioremap(uart_port[0].mapbase, 256);
>        uart_port[0].regshift = 2;
>        res = early_serial_setup(&uart_port[0]);
>        if (res)
>                return res;
> 
> 
> the +3 comes from the fact, that this machine is configured to run big
> endian.
>
Alternatively you could not use the byte ordering macro/functions as per 
the 'Byte Order' section in:

http://lwn.net/images/pdf/LDD3/ch11.pdf

Makes the code portable, understandable and...well neater.

Cheers

-- 
Alexander Clouter
.sigmonster says: Life is like a diaper -- short and loaded.


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