embedded-linux

There are many references to using i2c_smbus_ functions when developing embedded Linux software to communicate on the I2C bus. When i2c_smbus functions such as i2c_smbus_read_word_data are referenced in software project for ARM8 processor errors such as ‘ i2c_smbus_read_word_data’ was not declared in this scope are generated at compile. Investigation of the following header files indicate the absence of most i2c_smbus function definition. /usr/arm-linux-gnueabi/include/linux/i2c.h /usr/arm-linux-gnueabi/include/linux/i2c-dev.h Also in that following reference i2c.h file has all the i2c_smbus

Problem: I have to configure various LCD displays to be used by Android Platform. Almost in all cases there are no electrical specifications freely available for LCD displays on interest. But through experience and reverse engineering the parameters can be guessed reasonably well. I am trying to use Loadable Kernel Modules to fine tune the display parameters (any other suggestions are welcome too). Please find the relevant information below. HW: Atmel SAMA5D31-EK (ARM 5 processor) SW: Andriod Linux (Target), Ubuntu (Host System), Sourcery CodeBench (Cross Compiler) Code Snippets from board-dt

I've gathered some level of knowledge on several components (including software and hardware) which are involved in general DMA transactions in ARM based boards, but I don't understand how is it all perfectly integrated, I didn't find a full coherent description about this. I'll write down the high level of the knowledge I already have and I hope that someone could fix me where I'm wrong and complete the missing parts so the whole picture would be clear. My description starts with the userspace software and drills down to the hardware components. The misunderstood parts are in italic-bold

From the spec, I knew the following information: JGPIO1 PIN# :10 SoC GPIO # : 71 USE select: IO 0x532[7] ( 0 = native function, 1 = GPIO ) IO select: IO 0x536[7] (0 = output, 1 = input ) Level: IO 0x540[7] ( 0 = low, 1= high ) In this case, I want to program GPIO pin # 10. Is there any example or sample code I can refer to ? I can do this thorugh RW-everything [1] . However, this is in Windows. I want to do this in C and in linux environment. Please advise. =============================================================== For example, If I want to set The 7th bit to 1 at 0x532 The 7th bit to 0

Has anybody ported Chipsee 7 inch LCD on Linux kernel 3.14 or later ? Is there any patch available for the same ? If no patches any suggestion porting Chipsee LCD support from Linux kernel 3.8 to Linux kernel 3.14 ? Update: `/* * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/ * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ /dts-v1/; #include "am33xx.dtsi" #include "am335x-bone-common.dtsi" &ldo3_reg { regulator-min-microvolt =

I am writing a kernel module and need to perform reads from an existing block device. (/dev/something). Does anyone know of any other modules that do these that I can use as reference ? Any pointers would be welcome (Linux.2.6.30) If you really absolutely must then use the filp_open , filp_close , vfs_read and vfs_write functions. The description for for filp_open states "This is the helper to open a file from kernelspace if you really have to. But in generally you should not do this, so please move along, nothing to see here.." There is an excellent article "Driving Me Nuts - Things You Never