^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) ==========================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) S3C24XX ARM Linux Overview
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) ==========================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) Introduction
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) ------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) The Samsung S3C24XX range of ARM9 System-on-Chip CPUs are supported
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) by the 's3c2410' architecture of ARM Linux. Currently the S3C2410,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) S3C2412, S3C2413, S3C2416, S3C2440, S3C2442, S3C2443 and S3C2450 devices
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) are supported.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) Support for the S3C2400 and S3C24A0 series was never completed and the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) corresponding code has been removed after a while. If someone wishes to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) revive this effort, partial support can be retrieved from earlier Linux
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) versions.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) The S3C2416 and S3C2450 devices are very similar and S3C2450 support is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) included under the arch/arm/mach-s3c2416 directory. Note, while core
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) support for these SoCs is in, work on some of the extra peripherals
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) and extra interrupts is still ongoing.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) Configuration
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) -------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) A generic S3C2410 configuration is provided, and can be used as the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) default by `make s3c2410_defconfig`. This configuration has support
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) for all the machines, and the commonly used features on them.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) Certain machines may have their own default configurations as well,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) please check the machine specific documentation.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) Layout
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) ------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) The core support files are located in the platform code contained in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) arch/arm/plat-s3c24xx with headers in include/asm-arm/plat-s3c24xx.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) This directory should be kept to items shared between the platform
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) code (arch/arm/plat-s3c24xx) and the arch/arm/mach-s3c24* code.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) Each cpu has a directory with the support files for it, and the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) machines that carry the device. For example S3C2410 is contained
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) in arch/arm/mach-s3c2410 and S3C2440 in arch/arm/mach-s3c2440
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) Register, kernel and platform data definitions are held in the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) arch/arm/mach-s3c2410 directory./include/mach
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) arch/arm/plat-s3c24xx:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) Files in here are either common to all the s3c24xx family,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) or are common to only some of them with names to indicate this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) status. The files that are not common to all are generally named
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) with the initial cpu they support in the series to ensure a short
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) name without any possibility of confusion with newer devices.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) As an example, initially s3c244x would cover s3c2440 and s3c2442, but
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) with the s3c2443 which does not share many of the same drivers in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) this directory, the name becomes invalid. We stick to s3c2440-<x>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) to indicate a driver that is s3c2440 and s3c2442 compatible.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) This does mean that to find the status of any given SoC, a number
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) of directories may need to be searched.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) Machines
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) --------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) The currently supported machines are as follows:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) Simtec Electronics EB2410ITX (BAST)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) A general purpose development board, see EB2410ITX.txt for further
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) details
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) Simtec Electronics IM2440D20 (Osiris)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) CPU Module from Simtec Electronics, with a S3C2440A CPU, nand flash
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) and a PCMCIA controller.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) Samsung SMDK2410
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) Samsung's own development board, geared for PDA work.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) Samsung/Aiji SMDK2412
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) The S3C2412 version of the SMDK2440.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) Samsung/Aiji SMDK2413
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) The S3C2412 version of the SMDK2440.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) Samsung/Meritech SMDK2440
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) The S3C2440 compatible version of the SMDK2440, which has the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) option of an S3C2440 or S3C2442 CPU module.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) Thorcom VR1000
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) Custom embedded board
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) HP IPAQ 1940
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) Handheld (IPAQ), available in several varieties
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) HP iPAQ rx3715
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) S3C2440 based IPAQ, with a number of variations depending on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) features shipped.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) Acer N30
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) A S3C2410 based PDA from Acer. There is a Wiki page at
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) http://handhelds.org/moin/moin.cgi/AcerN30Documentation .
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) AML M5900
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) American Microsystems' M5900
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) Nex Vision Nexcoder
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) Nex Vision Otom
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) Two machines by Nex Vision
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) Adding New Machines
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) -------------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) The architecture has been designed to support as many machines as can
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) be configured for it in one kernel build, and any future additions
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) should keep this in mind before altering items outside of their own
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) machine files.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) Machine definitions should be kept in linux/arch/arm/mach-s3c2410,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) and there are a number of examples that can be looked at.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) Read the kernel patch submission policies as well as the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) Documentation/arm directory before submitting patches. The
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) ARM kernel series is managed by Russell King, and has a patch system
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) located at http://www.arm.linux.org.uk/developer/patches/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) as well as mailing lists that can be found from the same site.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) As a courtesy, please notify <ben-linux@fluff.org> of any new
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) machines or other modifications.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) Any large scale modifications, or new drivers should be discussed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) on the ARM kernel mailing list (linux-arm-kernel) before being
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) attempted. See http://www.arm.linux.org.uk/mailinglists/ for the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) mailing list information.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) I2C
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) ---
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) The hardware I2C core in the CPU is supported in single master
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) mode, and can be configured via platform data.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) RTC
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) ---
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) Support for the onboard RTC unit, including alarm function.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) This has recently been upgraded to use the new RTC core,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) and the module has been renamed to rtc-s3c to fit in with
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) the new rtc naming scheme.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) Watchdog
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) --------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) The onchip watchdog is available via the standard watchdog
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) interface.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) NAND
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) ----
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) The current kernels now have support for the s3c2410 NAND
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) controller. If there are any problems the latest linux-mtd
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) code can be found from http://www.linux-mtd.infradead.org/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) For more information see Documentation/arm/samsung-s3c24xx/nand.rst
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) SD/MMC
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) ------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) The SD/MMC hardware pre S3C2443 is supported in the current
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) kernel, the driver is drivers/mmc/host/s3cmci.c and supports
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) 1 and 4 bit SD or MMC cards.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) The SDIO behaviour of this driver has not been fully tested. There is no
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) current support for hardware SDIO interrupts.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) Serial
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) ------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) The s3c2410 serial driver provides support for the internal
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) serial ports. These devices appear as /dev/ttySAC0 through 3.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) To create device nodes for these, use the following commands
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) mknod ttySAC0 c 204 64
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) mknod ttySAC1 c 204 65
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) mknod ttySAC2 c 204 66
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) GPIO
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) ----
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) The core contains support for manipulating the GPIO, see the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) documentation in GPIO.txt in the same directory as this file.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) Newer kernels carry GPIOLIB, and support is being moved towards
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) this with some of the older support in line to be removed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) As of v2.6.34, the move towards using gpiolib support is almost
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) complete, and very little of the old calls are left.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) See Documentation/arm/samsung-s3c24xx/gpio.rst for the S3C24XX specific
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) support and Documentation/arm/samsung/gpio.rst for the core Samsung
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) implementation.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) Clock Management
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) ----------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) The core provides the interface defined in the header file
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) include/asm-arm/hardware/clock.h, to allow control over the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) various clock units
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) Suspend to RAM
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) --------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) For boards that provide support for suspend to RAM, the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) system can be placed into low power suspend.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) See Suspend.txt for more information.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) SPI
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) ---
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) SPI drivers are available for both the in-built hardware
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) (although there is no DMA support yet) and a generic
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) GPIO based solution.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) LEDs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) ----
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) There is support for GPIO based LEDs via a platform driver
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) in the LED subsystem.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) Platform Data
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) -------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) Whenever a device has platform specific data that is specified
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) on a per-machine basis, care should be taken to ensure the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) following:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) 1) that default data is not left in the device to confuse the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) driver if a machine does not set it at startup
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) 2) the data should (if possible) be marked as __initdata,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) to ensure that the data is thrown away if the machine is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) not the one currently in use.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) The best way of doing this is to make a function that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) kmalloc()s an area of memory, and copies the __initdata
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) and then sets the relevant device's platform data. Making
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) the function `__init` takes care of ensuring it is discarded
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) with the rest of the initialisation code::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) static __init void s3c24xx_xxx_set_platdata(struct xxx_data *pd)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) struct s3c2410_xxx_mach_info *npd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) npd = kmalloc(sizeof(struct s3c2410_xxx_mach_info), GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) if (npd) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) memcpy(npd, pd, sizeof(struct s3c2410_xxx_mach_info));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) s3c_device_xxx.dev.platform_data = npd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) printk(KERN_ERR "no memory for xxx platform data\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) Note, since the code is marked as __init, it should not be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) exported outside arch/arm/mach-s3c2410/, or exported to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) modules via EXPORT_SYMBOL() and related functions.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) Port Contributors
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) -----------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) Ben Dooks (BJD)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) Vincent Sanders
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) Herbert Potzl
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) Arnaud Patard (RTP)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) Roc Wu
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) Klaus Fetscher
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) Dimitry Andric
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) Shannon Holland
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) Guillaume Gourat (NexVision)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) Christer Weinigel (wingel) (Acer N30)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) Lucas Correia Villa Real (S3C2400 port)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) Document Author
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) ---------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) Ben Dooks, Copyright 2004-2006 Simtec Electronics
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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