From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.87 #1 (Red Hat Linux)) id 1dc7X5-0008Pq-5T for barebox@lists.infradead.org; Mon, 31 Jul 2017 10:02:41 +0000 Message-ID: <1501495333.2431.1.camel@pengutronix.de> From: Lucas Stach Date: Mon, 31 Jul 2017 12:02:13 +0200 In-Reply-To: <20170727050055.14188-1-o.rempel@pengutronix.de> References: <20170727050055.14188-1-o.rempel@pengutronix.de> Mime-Version: 1.0 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: Re: [PATCH v1 1/2] of: base: port of_device_is_big_endian from linux To: Oleksij Rempel Cc: barebox@lists.infradead.org Am Donnerstag, den 27.07.2017, 07:00 +0200 schrieb Oleksij Rempel: > > commit 37786c7fee40771d13901de129af7e084ed48b55 > > Author: Kevin Cernekee > > Date: Thu Apr 9 13:05:14 2015 -0700 > > > > of: Add helper function to check MMIO register endianness > > > > SoC peripherals can come in several different flavors: > > > > - little-endian: registers always need to be accessed in LE > > mode (so the > > kernel should perform a swap if the CPU is running BE) > > > > - big-endian: registers always need to be accessed in BE mode > > (so the > > kernel should perform a swap if the CPU is running LE) > > > > - native-endian: the bus will automatically swap accesses, so > > the kernel > > should never swap > > > > Introduce a function that checks an OF device node to see > > whether it > > contains a "big-endian" or "native-endian" property. For the > > former case, > > always return true. For the latter case, return true iff the > > kernel was > > built for BE (implying that the BE MMIO accessors do not perform > > a swap). > > Otherwise return false, assuming LE registers. > > > > LE registers are assumed by default because most existing > > drivers (libahci, > > serial8250, usb) always use readl/writel in the absence of > > instructions > > to the contrary, so that will be our fallback. > > Signed-off-by: Oleksij Rempel I guess this should be your private mail address? > --- > drivers/of/base.c | 23 +++++++++++++++++++++++ > include/of.h | 1 + > 2 files changed, 24 insertions(+) > > diff --git a/drivers/of/base.c b/drivers/of/base.c > index ea330d1310..95bea4ee83 100644 > --- a/drivers/of/base.c > +++ b/drivers/of/base.c > @@ -1622,6 +1622,29 @@ int of_device_is_available(const struct > device_node *device) > EXPORT_SYMBOL(of_device_is_available); > > /** > + * of_device_is_big_endian - check if a device has BE registers > + * > + * @device: Node to check for endianness > + * > + * Returns true if the device has a "big-endian" property, or if > the kernel > + * was compiled for BE *and* the device has a "native-endian" > property. > + * Returns false otherwise. > + * > + * Callers would nominally use ioread32be/iowrite32be if > + * of_device_is_big_endian() == true, or readl/writel otherwise. > + */ > +bool of_device_is_big_endian(const struct device_node *device) > +{ > + if (of_property_read_bool(device, "big-endian")) > + return true; > + if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) && > + of_property_read_bool(device, "native-endian")) > + return true; > + return false; > +} > +EXPORT_SYMBOL(of_device_is_big_endian); > + > +/** > * of_get_parent - Get a node's parent if any > * @node: Node to get parent > * > diff --git a/include/of.h b/include/of.h > index 0ba73f197f..4563cbeddd 100644 > --- a/include/of.h > +++ b/include/of.h > @@ -150,6 +150,7 @@ extern int of_machine_is_compatible(const char > *compat); > extern int of_device_is_compatible(const struct device_node *device, > const char *compat); > extern int of_device_is_available(const struct device_node *device); > +extern bool of_device_is_big_endian(const struct device_node > *device); This misses a stub implementation for !CONFIG_OFTREE _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox