Embedded-linux

I2C with  segment display

#include <LPC214x.h>
#include <stdio.h>

#define MAX  6
//<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<   Declarations  >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
void I2C_ISR(void)__irq;
void Wait (unsigned int);
void I2C_Init (void);

Embedded-linux

File Name: arch/arm/mach-omap2/board_am335x_evm.c 
Complete analysis of template board file, this file gives minium requirements 
for the board to up and it gives priority to user to add other I/O devices such
as LCD, MMC, NAND for providing kerenl support.

MACHINE_START(AM335XEVM, "am335xevm")
        /* Maintainer: Texas Instruments */
        .atag_offset    = 0x100,
        .map_io         = am335x_evm_map_io,
        .init_early     = am33xx_init_early,

Embedded-linux

For Kerenl porting/u-boot porting there are 3 types of files added/changed

1.cpu spefic files  [arm cortex-A8 processor]
2.Machine/architecture spefic files [AM335x ]
3.Board spefic files [Beagle bone]

Machine/Architecture spefic files are presented commonly in cpu and 
board realted files for ex.arch/arm/cpu/armv7/am335x/*.c 
[for armv7 processor --are cortex A8 and for am335x architecture spefic]

Embedded-linux

For adding ethernet support platform supported PHY values are added

File Name : "arch/arm/mach-omap2/include/mach/board-am335xevm.h"

+
+/* Define Ethernet Phy Types */
+#define MII_MODE_ENABLE         0x0
+#define RMII_MODE_ENABLE        0x5
+#define RGMII_MODE_ENABLE       0xA
+#define MAC_MII_SEL             0x650

Embedded-linux

Enable Backlight Support:

File Names changed :  arch/arm/mach-omap2/board-am335xevm.c
                      arch/arm/mach-omap2/mux33xx.c

File Name:  arch/arm/mach-omap2/board-am335xevm.c


-------------------------------------------------------------------------------------------
+#include <linux/pwm/pwm.h>

Embedded-linux

Files to chnage: arch/arm/mach-omap2/board-am335xevm.c

------------------------------------------------------------------------

+	bbcape7lcd_init();

------------------------------------------------------------------------
Initilization of bbcape7" lcd function declaration

Embedded-linux

Files to change: arch/arm/board-am335xevm.c

-------------------------------------------------------------------------
+#include <linux/input/ti_tsc.h>
+#include <linux/mfd/ti_tscadc.h>
-------------------------------------------------------------------------
Header files incluing for structure ti_tsc variables and 
register offset values of the device "TFC_S9700RTWV35TR_01B"  

-------------------------------------------------------------------------

Embedded-linux

Template Files : arch/arm/cpu/armv7/am33xx/board.c
                 arch/arm/cpu/armv7/am33xx/emif4.c
                 arch/arm/cpu/armv7/am33xx/mem.c
                 board/ti/am335x/board.c
                 board/ti/am335x/mux.c
                 board/ti/am335x/uboot.lds
                 boards.cfg
                 include/configs/am335x_evm.h
                 

Embedded-linux

Writing I2C Platform Driver and Code Flow:

File Name: arch/arm/mach-versatile/versatile-pb.c

Function Name: versatile_init(); -----------> arch/arm/mach-versatile/core.c --------------> 
                                      platform_device_register(&versatile_i2c_device);
                                      
                                      
                                      
Machine File is registering i2c device with function name platform_device_register()

Embedded-linux

The OS functions supported at kernel level are, of course, only those functions programmed inside it:

kmalloc(), kfree(): memory management

cli(), sti(): enable/disable interrupts

add_timer(), init_timer(), del_timer(): timing management

request_irq(), free_irq(): irq management