From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from imap.sh.mvista.com (unknown [63.81.120.155]) by ozlabs.org (Postfix) with ESMTP id 8E92FDE0E3 for ; Thu, 3 Apr 2008 23:26:15 +1100 (EST) Message-ID: <47F4CCBA.9060706@ru.mvista.com> Date: Thu, 03 Apr 2008 16:25:30 +0400 From: Sergei Shtylyov MIME-Version: 1.0 To: John Linn Subject: Re: [PATCH 2/3] [POWERPC][V3] Xilinx: of_serial support for Xilinx uart 16550. References: <20080402232213.5D87515B8067@mail37-sin.bigfish.com> In-Reply-To: <20080402232213.5D87515B8067@mail37-sin.bigfish.com> Content-Type: text/plain; charset=us-ascii; format=flowed Cc: linuxppc-dev@ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Hello. John Linn wrote: > The Xilinx 16550 uart core is not a standard 16550 because it uses > word-based addressing rather than byte-based addressing. With > additional properties it is compatible with the open firmware > 'ns16550' compatible binding. > This code updates the of_serial driver to handle the reg-offset > and reg-shift properties to enable this core to be used. > Signed-off-by: John Linn > --- > diff --git a/drivers/serial/of_serial.c b/drivers/serial/of_serial.c > index 2efb892..73c47a5 100644 > --- a/drivers/serial/of_serial.c > +++ b/drivers/serial/of_serial.c > @@ -31,7 +31,8 @@ static int __devinit of_platform_serial_setup(struct of_device *ofdev, > struct resource resource; > struct device_node *np = ofdev->node; > const unsigned int *clk, *spd; > - int ret; > + const u32 *prop; > + int ret, prop_size; > > memset(port, 0, sizeof *port); > spd = of_get_property(np, "current-speed", NULL); > @@ -49,6 +50,17 @@ static int __devinit of_platform_serial_setup(struct of_device *ofdev, > > spin_lock_init(&port->lock); > port->mapbase = resource.start; > + > + /* Check for shifted address mapping */ > + prop = of_get_property(np, "reg-offset", &prop_size); > + if (prop && (prop_size == sizeof(u32))) > + port->mapbase += *prop; I disagree. That trick leads to I/O resource misaccounting/misreporting. You should teach 8250.c about the offset trick instead, just as it's been taught the shift trick in its time. > + > + /* Check for registers offset within the devices address range */ > + prop = of_get_property(np, "reg-shift", &prop_size); > + if (prop && (prop_size == sizeof(u32))) > + port->regshift = *prop; > + > port->irq = irq_of_parse_and_map(np, 0); > port->iotype = UPIO_MEM; > port->type = type; WBR, Sergei