can: grcan: Add device driver for GRCAN and GRHCAN cores

This driver supports GRCAN and CRHCAN CAN controllers available in the GRLIB
VHDL IP core library.
Signed-off-by: Andreas Larsson <andreas@gaisler.com>
Acked-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

Documentation/ABI/testing/sysfs-class-net-grcan

+
+What:		/sys/class/net/<iface>/grcan/enable0
+Date:		October 2012
+KernelVersion:	3.8
+Contact:	Andreas Larsson <andreas@gaisler.com>
+Description:
+		Hardware configuration of physical interface 0. This file reads
+		and writes the "Enable 0" bit of the configuration register.
+		Possible values: 0 or 1. See the GRCAN chapter of the GRLIB IP
+		core library documentation for details. The default value is 0
+		or set by the module parameter grcan.enable0 and can be read at
+		/sys/module/grcan/parameters/enable0.
+
+What:		/sys/class/net/<iface>/grcan/enable1
+Date:		October 2012
+KernelVersion:	3.8
+Contact:	Andreas Larsson <andreas@gaisler.com>
+Description:
+		Hardware configuration of physical interface 1. This file reads
+		and writes the "Enable 1" bit of the configuration register.
+		Possible values: 0 or 1. See the GRCAN chapter of the GRLIB IP
+		core library documentation for details. The default value is 0
+		or set by the module parameter grcan.enable1 and can be read at
+		/sys/module/grcan/parameters/enable1.
+
+What:		/sys/class/net/<iface>/grcan/select
+Date:		October 2012
+KernelVersion:	3.8
+Contact:	Andreas Larsson <andreas@gaisler.com>
+Description:
+		Configuration of which physical interface to be used. Possible
+		values: 0 or 1. See the GRCAN chapter of the GRLIB IP core
+		library documentation for details. The default value is 0 or is
+		set by the module parameter grcan.select and can be read at
+		/sys/module/grcan/parameters/select.

Documentation/devicetree/bindings/net/can/grcan.txt

+Aeroflex Gaisler GRCAN and GRHCAN CAN controllers.
+
+The GRCAN and CRHCAN CAN controllers are available in the GRLIB VHDL IP core
+library.
+
+Note: These properties are built from the AMBA plug&play in a Leon SPARC system
+(the ordinary environment for GRCAN and GRHCAN). There are no dts files for
+sparc.
+
+Required properties:
+
+- name : Should be "GAISLER_GRCAN", "01_03d", "GAISLER_GRHCAN" or "01_034"
+
+- reg : Address and length of the register set for the device
+
+- freq : Frequency of the external oscillator clock in Hz (the frequency of
+	the amba bus in the ordinary case)
+
+- interrupts : Interrupt number for this device
+
+Optional properties:
+
+- systemid : If not present or if the value of the least significant 16 bits
+	of this 32-bit property is smaller than GRCAN_TXBUG_SAFE_GRLIB_VERSION
+	a bug workaround is activated.
+
+For further information look in the documentation for the GLIB IP core library:
+http://www.gaisler.com/products/grlib/grip.pdf

Documentation/kernel-parameters.txt

@@ -905,6 +905,24 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 	gpt		[EFI] Forces disk with valid GPT signature but
 			invalid Protective MBR to be treated as GPT.
 
+	grcan.enable0=	[HW] Configuration of physical interface 0. Determines
+			the "Enable 0" bit of the configuration register.
+			Format: 0 | 1
+			Default: 0
+	grcan.enable1=	[HW] Configuration of physical interface 1. Determines
+			the "Enable 0" bit of the configuration register.
+			Format: 0 | 1
+			Default: 0
+	grcan.select=	[HW] Select which physical interface to use.
+			Format: 0 | 1
+			Default: 0
+	grcan.txsize=	[HW] Sets the size of the tx buffer.
+			Format: <unsigned int> such that (txsize & ~0x1fffc0) == 0.
+			Default: 1024
+	grcan.rxsize=	[HW] Sets the size of the rx buffer.
+			Format: <unsigned int> such that (rxsize & ~0x1fffc0) == 0.
+			Default: 1024
+
 	hashdist=	[KNL,NUMA] Large hashes allocated during boot
 			are distributed across NUMA nodes.  Defaults on
 			for 64-bit NUMA, off otherwise.

drivers/net/can/Kconfig

@@ -110,6 +110,15 @@ config PCH_CAN
 	  is an IOH for x86 embedded processor (Intel Atom E6xx series).
 	  This driver can access CAN bus.
 
+config CAN_GRCAN
+	tristate "Aeroflex Gaisler GRCAN and GRHCAN CAN devices"
+	depends on CAN_DEV && OF
+	---help---
+	  Say Y here if you want to use Aeroflex Gaisler GRCAN or GRHCAN.
+	  Note that the driver supports little endian, even though little
+	  endian syntheses of the cores would need some modifications on
+	  the hardware level to work.
+
 source "drivers/net/can/mscan/Kconfig"
 
 source "drivers/net/can/sja1000/Kconfig"

drivers/net/can/Makefile

@@ -22,5 +22,6 @@ obj-$(CONFIG_CAN_BFIN)		+= bfin_can.o
 obj-$(CONFIG_CAN_JANZ_ICAN3)	+= janz-ican3.o
 obj-$(CONFIG_CAN_FLEXCAN)	+= flexcan.o
 obj-$(CONFIG_PCH_CAN)		+= pch_can.o
+obj-$(CONFIG_CAN_GRCAN)		+= grcan.o
 
 ccflags-$(CONFIG_CAN_DEBUG_DEVICES) := -DDEBUG