From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andre Przywara Subject: Re: [RFC 01/24] xen/char: dt-uart: Allow the user to give a path to the node Date: Fri, 16 Aug 2013 23:25:43 +0200 Message-ID: <520E98D7.6010405@linaro.org> References: <1376687156-6737-1-git-send-email-julien.grall@linaro.org> <1376687156-6737-2-git-send-email-julien.grall@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1376687156-6737-2-git-send-email-julien.grall@linaro.org> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Julien Grall Cc: patches@linaro.org, xen-devel@lists.xen.org, ian.campbell@citrix.com, stefano.stabellini@eu.citrix.com List-Id: xen-devel@lists.xenproject.org On 08/16/2013 11:05 PM, Julien Grall wrote: > On some board, there is no alias to the UART. To avoid modification in > the device tree, dt-uart should also search device by path. Funny, it wrote almost the same patch two days ago (including the variable renaming, minus the "/" check). Thanks for saving me the cleanup and send-out ;-) It is really useful for Midway! > To distinguish an alias from a path, dt-uart will check the first character. > If it's a / then it's path, otherwise it's an alias. Is that really needed? In my patch I just try it as an alias first, if there is no match (dev == NULL), I try the full path. Are there any ambiguities expected between an alias and a full path? Regards, Andre. > Signed-off-by: Julien Grall > --- > xen/drivers/char/dt-uart.c | 16 ++++++++++------ > 1 file changed, 10 insertions(+), 6 deletions(-) > > diff --git a/xen/drivers/char/dt-uart.c b/xen/drivers/char/dt-uart.c > index 93bb0f5..d7204fb 100644 > --- a/xen/drivers/char/dt-uart.c > +++ b/xen/drivers/char/dt-uart.c > @@ -26,9 +26,10 @@ > > /* > * Configure UART port with a string: > - * alias,options > + * path,options > * > - * @alias: alias used in the device tree for the UART > + * @path: full path used in the device tree for the UART. If the path > + * doesn't start with '/', we assuming that it's an alias. > * @options: UART speficic options (see in each UART driver) > */ > static char __initdata opt_dtuart[30] = ""; > @@ -38,7 +39,7 @@ void __init dt_uart_init(void) > { > struct dt_device_node *dev; > int ret; > - const char *devalias = opt_dtuart; > + const char *devpath = opt_dtuart; > char *options; > > if ( !console_has("dtuart") || !strcmp(opt_dtuart, "") ) > @@ -53,12 +54,15 @@ void __init dt_uart_init(void) > else > options = ""; > > - early_printk("Looking for UART console %s\n", devalias); > - dev = dt_find_node_by_alias(devalias); > + early_printk("Looking for UART console %s\n", devpath); > + if ( *devpath == '/' ) > + dev = dt_find_node_by_path(devpath); > + else > + dev = dt_find_node_by_alias(devpath); > > if ( !dev ) > { > - early_printk("Unable to find device \"%s\"\n", devalias); > + early_printk("Unable to find device \"%s\"\n", devpath); > return; > } > >