1 S3C24XX ARM Linux Overview 2 ========================== 3 4 5 6Introduction 7------------ 8 9 The Samsung S3C24XX range of ARM9 System-on-Chip CPUs are supported 10 by the 's3c2410' architecture of ARM Linux. Currently the S3C2410, 11 S3C2412, S3C2413, S3C2440 and S3C2442 devices are supported. 12 13 Support for the S3C2400 series is in progress. 14 15Configuration 16------------- 17 18 A generic S3C2410 configuration is provided, and can be used as the 19 default by `make s3c2410_defconfig`. This configuration has support 20 for all the machines, and the commonly used features on them. 21 22 Certain machines may have their own default configurations as well, 23 please check the machine specific documentation. 24 25 26Layout 27------ 28 29 The core support files are located in the platform code contained in 30 arch/arm/plat-s3c24xx with headers in include/asm-arm/plat-s3c24xx. 31 This directory should be kept to items shared between the platform 32 code (arch/arm/plat-s3c24xx) and the arch/arm/mach-s3c24* code. 33 34 Each cpu has a directory with the support files for it, and the 35 machines that carry the device. For example S3C2410 is contained 36 in arch/arm/mach-s3c2410 and S3C2440 in arch/arm/mach-s3c2440 37 38 Register, kernel and platform data definitions are held in the 39 include/asm-arm/arch-s3c2410 directory. 40 41 42Machines 43-------- 44 45 The currently supported machines are as follows: 46 47 Simtec Electronics EB2410ITX (BAST) 48 49 A general purpose development board, see EB2410ITX.txt for further 50 details 51 52 Simtec Electronics IM2440D20 (Osiris) 53 54 CPU Module from Simtec Electronics, with a S3C2440A CPU, nand flash 55 and a PCMCIA controller. 56 57 Samsung SMDK2410 58 59 Samsung's own development board, geared for PDA work. 60 61 Samsung/Aiji SMDK2412 62 63 The S3C2412 version of the SMDK2440. 64 65 Samsung/Aiji SMDK2413 66 67 The S3C2412 version of the SMDK2440. 68 69 Samsung/Meritech SMDK2440 70 71 The S3C2440 compatible version of the SMDK2440, which has the 72 option of an S3C2440 or S3C2442 CPU module. 73 74 Thorcom VR1000 75 76 Custom embedded board 77 78 HP IPAQ 1940 79 80 Handheld (IPAQ), available in several varieties 81 82 HP iPAQ rx3715 83 84 S3C2440 based IPAQ, with a number of variations depending on 85 features shipped. 86 87 Acer N30 88 89 A S3C2410 based PDA from Acer. There is a Wiki page at 90 http://handhelds.org/moin/moin.cgi/AcerN30Documentation . 91 92 AML M5900 93 94 American Microsystems' M5900 95 96 Nex Vision Nexcoder 97 Nex Vision Otom 98 99 Two machines by Nex Vision 100 101 102Adding New Machines 103------------------- 104 105 The architecture has been designed to support as many machines as can 106 be configured for it in one kernel build, and any future additions 107 should keep this in mind before altering items outside of their own 108 machine files. 109 110 Machine definitions should be kept in linux/arch/arm/mach-s3c2410, 111 and there are a number of examples that can be looked at. 112 113 Read the kernel patch submission policies as well as the 114 Documentation/arm directory before submitting patches. The 115 ARM kernel series is managed by Russell King, and has a patch system 116 located at http://www.arm.linux.org.uk/developer/patches/ 117 as well as mailing lists that can be found from the same site. 118 119 As a courtesy, please notify <ben-linux@fluff.org> of any new 120 machines or other modifications. 121 122 Any large scale modifications, or new drivers should be discussed 123 on the ARM kernel mailing list (linux-arm-kernel) before being 124 attempted. See http://www.arm.linux.org.uk/mailinglists/ for the 125 mailing list information. 126 127 128I2C 129--- 130 131 The hardware I2C core in the CPU is supported in single master 132 mode, and can be configured via platform data. 133 134 135RTC 136--- 137 138 Support for the onboard RTC unit, including alarm function. 139 140 This has recently been upgraded to use the new RTC core, 141 and the module has been renamed to rtc-s3c to fit in with 142 the new rtc naming scheme. 143 144 145Watchdog 146-------- 147 148 The onchip watchdog is available via the standard watchdog 149 interface. 150 151 152NAND 153---- 154 155 The current kernels now have support for the s3c2410 NAND 156 controller. If there are any problems the latest linux-mtd 157 code can be found from http://www.linux-mtd.infradead.org/ 158 159 160Serial 161------ 162 163 The s3c2410 serial driver provides support for the internal 164 serial ports. These devices appear as /dev/ttySAC0 through 3. 165 166 To create device nodes for these, use the following commands 167 168 mknod ttySAC0 c 204 64 169 mknod ttySAC1 c 204 65 170 mknod ttySAC2 c 204 66 171 172 173GPIO 174---- 175 176 The core contains support for manipulating the GPIO, see the 177 documentation in GPIO.txt in the same directory as this file. 178 179 180Clock Management 181---------------- 182 183 The core provides the interface defined in the header file 184 include/asm-arm/hardware/clock.h, to allow control over the 185 various clock units 186 187 188Suspend to RAM 189-------------- 190 191 For boards that provide support for suspend to RAM, the 192 system can be placed into low power suspend. 193 194 See Suspend.txt for more information. 195 196 197SPI 198--- 199 200 SPI drivers are available for both the in-built hardware 201 (although there is no DMA support yet) and a generic 202 GPIO based solution. 203 204 205LEDs 206---- 207 208 There is support for GPIO based LEDs via a platform driver 209 in the LED subsystem. 210 211 212Platform Data 213------------- 214 215 Whenever a device has platform specific data that is specified 216 on a per-machine basis, care should be taken to ensure the 217 following: 218 219 1) that default data is not left in the device to confuse the 220 driver if a machine does not set it at startup 221 222 2) the data should (if possible) be marked as __initdata, 223 to ensure that the data is thrown away if the machine is 224 not the one currently in use. 225 226 The best way of doing this is to make a function that 227 kmalloc()s an area of memory, and copies the __initdata 228 and then sets the relevant device's platform data. Making 229 the function `__init` takes care of ensuring it is discarded 230 with the rest of the initialisation code 231 232 static __init void s3c24xx_xxx_set_platdata(struct xxx_data *pd) 233 { 234 struct s3c2410_xxx_mach_info *npd; 235 236 npd = kmalloc(sizeof(struct s3c2410_xxx_mach_info), GFP_KERNEL); 237 if (npd) { 238 memcpy(npd, pd, sizeof(struct s3c2410_xxx_mach_info)); 239 s3c_device_xxx.dev.platform_data = npd; 240 } else { 241 printk(KERN_ERR "no memory for xxx platform data\n"); 242 } 243 } 244 245 Note, since the code is marked as __init, it should not be 246 exported outside arch/arm/mach-s3c2410/, or exported to 247 modules via EXPORT_SYMBOL() and related functions. 248 249 250Port Contributors 251----------------- 252 253 Ben Dooks (BJD) 254 Vincent Sanders 255 Herbert Potzl 256 Arnaud Patard (RTP) 257 Roc Wu 258 Klaus Fetscher 259 Dimitry Andric 260 Shannon Holland 261 Guillaume Gourat (NexVision) 262 Christer Weinigel (wingel) (Acer N30) 263 Lucas Correia Villa Real (S3C2400 port) 264 265 266Document Author 267--------------- 268 269Ben Dooks, (c) 2004-2005,2006 Simtec Electronics 270