sw:drv: add I2C driver from Linux

Signed-off-by: Federico Vaga <federico.vaga@cern.ch>

software/i2c-ocore/.gitignore

+*.o
+*.ko
+*.mod.c
+.*.o.cmd
+.*.ko.cmd
+*.mod.d
+*.o.d
+*.tmp
+.tmp_versions
+modules.order
+Module.symvers
+\#*
+*~

software/i2c-ocore/Documentation/i2c/busses/i2c-ocores

+Kernel driver i2c-ocores
+
+Supported adapters:
+  * OpenCores.org I2C controller by Richard Herveille (see datasheet link)
+    https://opencores.org/project/i2c/overview
+
+Author: Peter Korsgaard <peter@korsgaard.com>
+
+Description
+-----------
+
+i2c-ocores is an i2c bus driver for the OpenCores.org I2C controller
+IP core by Richard Herveille.
+
+Usage
+-----
+
+i2c-ocores uses the platform bus, so you need to provide a struct
+platform_device with the base address and interrupt number. The
+dev.platform_data of the device should also point to a struct
+ocores_i2c_platform_data (see linux/platform_data/i2c-ocores.h) describing the
+distance between registers and the input clock speed.
+There is also a possibility to attach a list of i2c_board_info which
+the i2c-ocores driver will add to the bus upon creation.
+
+E.G. something like:
+
+static struct resource ocores_resources[] = {
+	[0] = {
+		.start	= MYI2C_BASEADDR,
+		.end	= MYI2C_BASEADDR + 8,
+		.flags	= IORESOURCE_MEM,
+	},
+	[1] = {
+		.start	= MYI2C_IRQ,
+		.end	= MYI2C_IRQ,
+		.flags	= IORESOURCE_IRQ,
+	},
+};
+
+/* optional board info */
+struct i2c_board_info ocores_i2c_board_info[] = {
+	{
+		I2C_BOARD_INFO("tsc2003", 0x48),
+		.platform_data = &tsc2003_platform_data,
+		.irq = TSC_IRQ
+	},
+	{
+		I2C_BOARD_INFO("adv7180", 0x42 >> 1),
+		.irq = ADV_IRQ
+	}
+};
+
+static struct ocores_i2c_platform_data myi2c_data = {
+	.regstep	= 2,		/* two bytes between registers */
+	.clock_khz	= 50000,	/* input clock of 50MHz */
+	.devices	= ocores_i2c_board_info, /* optional table of devices */
+	.num_devices	= ARRAY_SIZE(ocores_i2c_board_info), /* table size */
+};
+
+static struct platform_device myi2c = {
+	.name			= "ocores-i2c",
+	.dev = {
+		.platform_data	= &myi2c_data,
+	},
+	.num_resources		= ARRAY_SIZE(ocores_resources),
+	.resource		= ocores_resources,
+};

software/i2c-ocore/Makefile

+-include Makefile.specific
+# include parent_common.mk for buildsystem's defines
+#use absolute path for REPO_PARENT
+REPO_PARENT ?= $(shell /bin/pwd)/../..
+-include $(REPO_PARENT)/parent_common.mk
+
+all: modules
+
+modules help install modules_install clean:
+	export CONFIG_I2C_OCORES=m
+	make -C $(shell pwd)/drivers/i2c/busses $@
+
+.PHONY: all modules clean help install modules_install

software/i2c-ocore/README

+Backport i2c-ocores from Linux
\ No newline at end of file

software/i2c-ocore/drivers/i2c/busses/Kbuild

+ccflags-y += -I$(src)/../../../include
+
+# priority to our local headers
+LINUXINCLUDE :=  -I$(src)/../../../include -I$(src)/../../../include/linux $(LINUXINCLUDE)
+
+obj-$(CONFIG_I2C_OCORES) += i2c-ocores.o
\ No newline at end of file

software/i2c-ocore/drivers/i2c/busses/Makefile

+-include Makefile.specific
+# include parent_common.mk for buildsystem's defines
+#use absolute path for REPO_PARENT
+REPO_PARENT ?= $(shell /bin/pwd)/../..
+-include $(REPO_PARENT)/parent_common.mk
+
+LINUX ?= /lib/modules/$(shell uname -r)/build
+export LINUX=/user/fvaga/workspace/projects/centos/cern-beco-kernel-rt/BUILD/kernel-3.10.0/linux-3.10.0.x86_64
+
+export CONFIG_I2C_OCORES=m
+
+all: modules
+
+modules help install modules_install:
+	make -C $(LINUX) M=$(shell pwd)
+
+.PHONY: all modules clean help install modules_install