This patch changes the of_xlate API to make it possible for multiple
gpio_chips to refer to the same device tree node. This is useful for
banked GPIO controllers that use multiple gpio_chips for a single
device. With this change the core code will try calling of_xlate on
each gpio_chip that references the device_node and will return the
gpio number for the first one to return 'true'.
Tested-by: Roland Stigge <stigge@antcom.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
of_parse_phandle_with_args() needs to return quite a bit of data. Rather
than making each datum a separate **out_ argument, this patch creates
struct of_phandle_args to contain all the returned data and reworks the
user of the function. This patch also enables of_parse_phandle_with_args()
to return the device node pointer for the phandle node.
This patch also ends up being fairly major surgery to
of_parse_handle_with_args(). The existing structure didn't work well
when extending to use of_phandle_args, and I discovered bugs during testing.
I also took the opportunity to rename the function to be like the
existing of_parse_phandle().
v2: - moved declaration of of_phandle_args to fix compile on non-DT builds
- fixed incorrect index in example usage
- fixed incorrect return code handling for empty entries
Reviewed-by: Shawn Guo <shawn.guo@freescale.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Allow GPIO drivers to use of_gpio_simple_xlate. This is useful for the
generic GPIO driver for example where gpio_chip is embedded in
bgpio_chip and doesn't need of_mm_gpio_chip but has a simple 1:1 GPIO
mapping.
Cc: Anton Vorontsov <avorontsov@ru.mvista.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Jamie Iles <jamie@jamieiles.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
This patch adds a new routine, of_get_named_gpio_flags(), which takes the
property name as a parameter rather than assuming "gpios".
of_get_gpio_flags() is modified to call of_get_named_gpio_flags() with "gpios"
as the property parameter.
Signed-off-by: John Bonesio <bones@secretlab.ca>
[grant.likely: Tidied up whitespace and tweaked kerneldoc comments.]
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Implement generic OF gpio hooks and thus make device-enabled GPIO chips
(i.e. the ones that have gpio_chip->dev specified) automatically attach
to the OpenFirmware subsystem. Which means that now we can handle I2C and
SPI GPIO chips almost* transparently.
* "Almost" because some chips still require platform data, and for these
chips OF-glue is still needed, though with this change the glue will
be much smaller.
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Bill Gatliff <bgat@billgatliff.com>
Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
CC: linux-kernel@vger.kernel.org
CC: devicetree-discuss@lists.ozlabs.org
Currently the kernel uses the struct device_node.data pointer to resolve
a struct gpio_chip pointer from a device tree node. However, the .data
member doesn't provide any type checking and there aren't any rules
enforced on what it should be used for. There's no guarantee that the
data stored in it actually points to an gpio_chip pointer.
Instead of relying on the .data pointer, this patch modifies the code
to add a lookup function which scans through the registered gpio_chips
and returns the gpio_chip that has a pointer to the specified
device_node.
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Anton Vorontsov <avorontsov@ru.mvista.com>
CC: Grant Likely <grant.likely@secretlab.ca>
CC: David Brownell <dbrownell@users.sourceforge.net>
CC: Bill Gatliff <bgat@billgatliff.com>
CC: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
CC: Benjamin Herrenschmidt <benh@kernel.crashing.org>
CC: Jean Delvare <khali@linux-fr.org>
CC: linux-kernel@vger.kernel.org
CC: devicetree-discuss@lists.ozlabs.org
The OF gpio infrastructure is great for describing GPIO connections within
the device tree. However, using a GPIO binding still requires changes to
the gpio controller just to add an of_gpio structure. In most cases, the
gpio controller doesn't actually need any special support and the simple
OF gpio mapping function is more than sufficient. Additional, the current
scheme of using of_gpio_chip requires a convoluted scheme to maintain
1:1 mappings between of_gpio_chip and gpio_chip instances.
If the struct of_gpio_chip data members were moved into struct gpio_chip,
then it would simplify the processing of OF gpio bindings, and it would
make it trivial to use device tree OF connections on existing gpiolib
controller drivers.
This patch eliminates the of_gpio_chip structure and moves the relevant
fields into struct gpio_chip (conditional on CONFIG_OF_GPIO). This move
simplifies the existing code and prepares for adding automatic device tree
support to existing drivers.
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Anton Vorontsov <avorontsov@ru.mvista.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Bill Gatliff <bgat@billgatliff.com>
Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Jean Delvare <khali@linux-fr.org>
This function is used to count how many GPIOs are specified for
a device node.
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This adds a new function, of_get_gpio_flags, which is like
of_get_gpio(), but accepts a new "flags" argument. This new function
will be used by the drivers that need to retrieve additional GPIO
information, such as active-low flag.
Also, this changes the default ("simple") .xlate routine to warn about
bogus (< 2) #gpio-cells usage: the second cell should always be present
for GPIO flags.
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Since commit 7560fa60fc (gpio: <linux/gpio.h>
and "no GPIO support here" stubs) drivers can use GPIOs if they're available,
but don't require them.
This patch actually enables this feature.
Signed-off-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This implements various helpers to support OF bindings for the GPIO
LIB API.
Previously this was PowerPC specific, but it seems this code isn't
arch-dependent anyhow, so let's place it into of/.
SPARC will not see this addition yet, real hardware seem to not use
GPIOs at all. But this might change:
http://www.leox.org/docs/faq_MLleon.html
"16-bit I/O port" sounds promising. :-)
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Paul Mackerras <paulus@samba.org>
