1 S3C24XX ARM Linux Overview
2 ==========================
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, S3C2416 S3C2440, S3C2442, S3C2443 and S3C2450 devices
14 Support for the S3C2400 and S3C24A0 series are in progress.
16 The S3C2416 and S3C2450 devices are very similar and S3C2450 support is
17 included under the arch/arm/mach-s3c2416 directory. Note, whilst core
18 support for these SoCs is in, work on some of the extra peripherals
19 and extra interrupts is still ongoing.
25 A generic S3C2410 configuration is provided, and can be used as the
26 default by `make s3c2410_defconfig`. This configuration has support
27 for all the machines, and the commonly used features on them.
29 Certain machines may have their own default configurations as well,
30 please check the machine specific documentation.
36 The core support files are located in the platform code contained in
37 arch/arm/plat-s3c24xx with headers in include/asm-arm/plat-s3c24xx.
38 This directory should be kept to items shared between the platform
39 code (arch/arm/plat-s3c24xx) and the arch/arm/mach-s3c24* code.
41 Each cpu has a directory with the support files for it, and the
42 machines that carry the device. For example S3C2410 is contained
43 in arch/arm/mach-s3c2410 and S3C2440 in arch/arm/mach-s3c2440
45 Register, kernel and platform data definitions are held in the
46 arch/arm/mach-s3c2410 directory./include/mach
48 arch/arm/plat-s3c24xx:
50 Files in here are either common to all the s3c24xx family,
51 or are common to only some of them with names to indicate this
52 status. The files that are not common to all are generally named
53 with the initial cpu they support in the series to ensure a short
54 name without any possibility of confusion with newer devices.
56 As an example, initially s3c244x would cover s3c2440 and s3c2442, but
57 with the s3c2443 which does not share many of the same drivers in
58 this directory, the name becomes invalid. We stick to s3c2440-<x>
59 to indicate a driver that is s3c2440 and s3c2442 compatible.
61 This does mean that to find the status of any given SoC, a number
62 of directories may need to be searched.
68 The currently supported machines are as follows:
70 Simtec Electronics EB2410ITX (BAST)
72 A general purpose development board, see EB2410ITX.txt for further
75 Simtec Electronics IM2440D20 (Osiris)
77 CPU Module from Simtec Electronics, with a S3C2440A CPU, nand flash
78 and a PCMCIA controller.
82 Samsung's own development board, geared for PDA work.
86 The S3C2412 version of the SMDK2440.
90 The S3C2412 version of the SMDK2440.
92 Samsung/Meritech SMDK2440
94 The S3C2440 compatible version of the SMDK2440, which has the
95 option of an S3C2440 or S3C2442 CPU module.
103 Handheld (IPAQ), available in several varieties
107 S3C2440 based IPAQ, with a number of variations depending on
112 A S3C2410 based PDA from Acer. There is a Wiki page at
113 http://handhelds.org/moin/moin.cgi/AcerN30Documentation .
117 American Microsystems' M5900
122 Two machines by Nex Vision
128 The architecture has been designed to support as many machines as can
129 be configured for it in one kernel build, and any future additions
130 should keep this in mind before altering items outside of their own
133 Machine definitions should be kept in linux/arch/arm/mach-s3c2410,
134 and there are a number of examples that can be looked at.
136 Read the kernel patch submission policies as well as the
137 Documentation/arm directory before submitting patches. The
138 ARM kernel series is managed by Russell King, and has a patch system
139 located at http://www.arm.linux.org.uk/developer/patches/
140 as well as mailing lists that can be found from the same site.
142 As a courtesy, please notify <ben-linux@fluff.org> of any new
143 machines or other modifications.
145 Any large scale modifications, or new drivers should be discussed
146 on the ARM kernel mailing list (linux-arm-kernel) before being
147 attempted. See http://www.arm.linux.org.uk/mailinglists/ for the
148 mailing list information.
154 The hardware I2C core in the CPU is supported in single master
155 mode, and can be configured via platform data.
161 Support for the onboard RTC unit, including alarm function.
163 This has recently been upgraded to use the new RTC core,
164 and the module has been renamed to rtc-s3c to fit in with
165 the new rtc naming scheme.
171 The onchip watchdog is available via the standard watchdog
178 The current kernels now have support for the s3c2410 NAND
179 controller. If there are any problems the latest linux-mtd
180 code can be found from http://www.linux-mtd.infradead.org/
182 For more information see Documentation/arm/Samsung-S3C24XX/NAND.txt
188 The SD/MMC hardware pre S3C2443 is supported in the current
189 kernel, the driver is drivers/mmc/host/s3cmci.c and supports
190 1 and 4 bit SD or MMC cards.
192 The SDIO behaviour of this driver has not been fully tested. There is no
193 current support for hardware SDIO interrupts.
199 The s3c2410 serial driver provides support for the internal
200 serial ports. These devices appear as /dev/ttySAC0 through 3.
202 To create device nodes for these, use the following commands
204 mknod ttySAC0 c 204 64
205 mknod ttySAC1 c 204 65
206 mknod ttySAC2 c 204 66
212 The core contains support for manipulating the GPIO, see the
213 documentation in GPIO.txt in the same directory as this file.
215 Newer kernels carry GPIOLIB, and support is being moved towards
216 this with some of the older support in line to be removed.
218 As of v2.6.34, the move towards using gpiolib support is almost
219 complete, and very little of the old calls are left.
225 The core provides the interface defined in the header file
226 include/asm-arm/hardware/clock.h, to allow control over the
233 For boards that provide support for suspend to RAM, the
234 system can be placed into low power suspend.
236 See Suspend.txt for more information.
242 SPI drivers are available for both the in-built hardware
243 (although there is no DMA support yet) and a generic
250 There is support for GPIO based LEDs via a platform driver
251 in the LED subsystem.
257 Whenever a device has platform specific data that is specified
258 on a per-machine basis, care should be taken to ensure the
261 1) that default data is not left in the device to confuse the
262 driver if a machine does not set it at startup
264 2) the data should (if possible) be marked as __initdata,
265 to ensure that the data is thrown away if the machine is
266 not the one currently in use.
268 The best way of doing this is to make a function that
269 kmalloc()s an area of memory, and copies the __initdata
270 and then sets the relevant device's platform data. Making
271 the function `__init` takes care of ensuring it is discarded
272 with the rest of the initialisation code
274 static __init void s3c24xx_xxx_set_platdata(struct xxx_data *pd)
276 struct s3c2410_xxx_mach_info *npd;
278 npd = kmalloc(sizeof(struct s3c2410_xxx_mach_info), GFP_KERNEL);
280 memcpy(npd, pd, sizeof(struct s3c2410_xxx_mach_info));
281 s3c_device_xxx.dev.platform_data = npd;
283 printk(KERN_ERR "no memory for xxx platform data\n");
287 Note, since the code is marked as __init, it should not be
288 exported outside arch/arm/mach-s3c2410/, or exported to
289 modules via EXPORT_SYMBOL() and related functions.
303 Guillaume Gourat (NexVision)
304 Christer Weinigel (wingel) (Acer N30)
305 Lucas Correia Villa Real (S3C2400 port)
311 Ben Dooks, Copyright 2004-2006 Simtec Electronics