Documentation/arm/Samsung-S3C24XX/Overview.txt

   1                         S3C24XX ARM Linux Overview
   2                         ==========================
   3
   4
   5
   6 Introduction
   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
  15 Configuration
  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
  26 Layout
  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
  42 Machines
  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
 102 Adding 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
 128 I2C
 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
 135 RTC
 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
 145 Watchdog
 146 --------
 147
 148   The onchip watchdog is available via the standard watchdog
 149   interface.
 150
 151
 152 NAND
 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
 160 Serial
 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
 173 GPIO
 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
 180 Clock 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
 188 Suspend 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
 197 SPI
 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
 205 LEDs
 206 ----
 207
 208   There is support for GPIO based LEDs via a platform driver
 209   in the LED subsystem.
 210
 211
 212 Platform 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
 250 Port 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
 266 Document Author
 267 ---------------
 268
 269 Ben Dooks, (c) 2004-2005,2006 Simtec Electronics