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Diffstat (limited to 'doc/driver-model/UDM-watchdog.txt')
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diff --git a/doc/driver-model/UDM-watchdog.txt b/doc/driver-model/UDM-watchdog.txt deleted file mode 100644 index 3f13063..0000000 --- a/doc/driver-model/UDM-watchdog.txt +++ /dev/null @@ -1,329 +0,0 @@ -The U-Boot Driver Model Project -=============================== -Watchdog device subsystem analysis -================================== - -Tomas Hlavacek <tmshlvck@gmail.com> -2012-03-09 - -I) Overview ------------ - -U-Boot currently implements an API for HW watchdog devices as explicit drivers -in drivers/watchdog directory. There are also drivers for both hardware and -software watchdog on particular CPUs implemented in arch/*/cpu/*/cpu.c. There -are macros in include/watchdog.h that selects between SW and HW watchdog and -assembly SW implementation. - -The current common interface comprises of one set out of these two possible -variants: - - 1) - void watchdog_reset(void); - int watchdog_disable(void); - int watchdog_init(void); - - 2) - void hw_watchdog_reset(void); - void hw_watchdog_init(void); - -The watchdog implementations are also spread through board/*/*.c that in -some cases. The API and semantics is in most cases same as the above -mentioned common functions. - - -II) Approach ------------- - - 1) New API - ---------- - - In the UDM each watchdog driver would register itself by a function - - int watchdog_device_register(struct instance *i, - const struct watchdog_device_ops *o); - - The structure being defined as follows: - - struct watchdog_device_ops { - int (*disable)(struct instance *i); - void (*reset)(struct instance *i); - }; - - The watchdog_init() function will be dissolved into probe() function. - - 2) Conversion thougths - ---------------------- - - Conversion of watchdog implementations to a new API could be divided - to three subsections: a) HW implementations, which are mostly compliant - to the above mentioned API; b) SW implementations, which are compliant - to the above mentioned API and c) SW implementations that are not compliant - to the API and has to be rectified or partially rewritten. - -III) Analysis of in-tree drivers --------------------------------- - - drivers/watchdog/at91sam9_wdt.c - ------------------------------- - The driver is standard HW watchdog. Simple conversion is possible. - - - drivers/watchdog/ftwdt010_wdt.c - ------------------------------- - The driver is ad-hoc HW watchdog. Conversion has to take into account - driver parts spread in include/faraday/*. Restructuring the driver and - code cleanup has to be considered. - - - arch/arm/cpu/arm1136/mx31/timer.c - --------------------------------- - The driver is semi-standard ad-hoc HW watchdog. Conversion has to take - into account driver parts spread in the timer.c file. - - - arch/arm/cpu/arm926ejs/davinci/timer.c - -------------------------------------- - The driver is ad-hoc semi-standard HW watchdog. Conversion has to take - into account driver parts spread in the timer.c file. - - - arch/arm/cpu/armv7/omap-common/hwinit-common.c - ---------------------------------------------- - The driver is non-standard ad-hoc HW watchdog. Conversion is possible - but functions has to be renamed and constants moved to another places. - - - arch/arm/cpu/armv7/omap3/board.c - -------------------------------- - The driver is non-standard ad-hoc HW watchdog. Conversion is possible - but functions has to be renamed and constants moved to another places. - - - arch/blackfin/cpu/watchdog.c - ---------------------------- - The driver is standard HW watchdog. Simple conversion is possible. - - - arch/m68k/cpu/mcf523x/cpu.c - --------------------------- - The driver is standard HW watchdog. Simple conversion is possible. - - - arch/m68k/cpu/mcf52x2/cpu.c - --------------------------- - The driver is standard HW watchdog. Simple conversion is possible. - - - arch/m68k/cpu/mcf532x/cpu.c - --------------------------- - The driver is standard HW watchdog. Simple conversion is possible. - - - arch/m68k/cpu/mcf547x_8x/cpu.c - ------------------------------ - The driver is standard HW watchdog (there is slight naming convention - violation that has to be rectified). Simple conversion is possible. - - - arch/powerpc/cpu/74xx_7xx/cpu.c - ------------------------------- - The driver is standard HW watchdog. Simple conversion is possible. - - - arch/powerpc/cpu/mpc512x/cpu.c - ------------------------------ - The driver is standard HW watchdog. Simple conversion is possible. - - - arch/powerpc/cpu/mpc5xx/cpu.c - ----------------------------- - The driver is standard HW watchdog. Simple conversion is possible. - - - arch/powerpc/cpu/mpc5xxx/cpu.c - ------------------------------ - The driver is standard HW watchdog. Simple conversion is possible. - - - arch/powerpc/cpu/mpc8260/cpu.c - ------------------------------ - The driver is standard HW watchdog. Simple conversion is possible. - - - arch/powerpc/cpu/mpc83xx/cpu.c - ------------------------------ - The driver is standard HW watchdog. Simple conversion is possible. - - - arch/powerpc/cpu/mpc85xx/cpu.c - ------------------------------ - The driver is standard HW watchdog. Simple conversion is possible. - - - arch/powerpc/cpu/mpc86xx/cpu.c - ------------------------------ - The driver is standard HW watchdog. Simple conversion is possible. - - - arch/powerpc/cpu/mpc8xx/cpu.c - ----------------------------- - The driver is standard HW watchdog. Simple conversion is possible. - - - arch/powerpc/cpu/ppc4xx/cpu.c - ----------------------------- - The driver is standard HW watchdog. Simple conversion is possible. - - - arch/sh/cpu/sh2/watchdog.c - -------------------------- - The driver is standard HW watchdog. Simple conversion is possible. - - - arch/sh/cpu/sh3/watchdog.c - -------------------------- - The driver is standard HW watchdog. Simple conversion is possible. - - - arch/sh/cpu/sh4/watchdog.c - -------------------------- - The driver is standard HW watchdog. Simple conversion is possible. - - - board/amcc/luan/luan.c - ---------------------- - The driver is standard HW watchdog. Simple conversion is possible. - - - board/amcc/yosemite/yosemite.c - ------------------------------ - The driver is standard HW watchdog. Simple conversion is possible. - - - board/apollon/apollon.c - ----------------------- - The driver is standard HW watchdog however the watchdog_init() - function is called in early initialization. Simple conversion is possible. - - - board/bmw/m48t59y.c - ------------------- - Special watchdog driver. Dead code. To be removed. - - - board/davedenx/qong/qong.c - -------------------------- - The driver is standard HW watchdog. Simple conversion is possible. - - - board/dvlhost/watchdog.c - ------------------------ - The driver is standard HW watchdog. Simple conversion is possible. - - - board/eNET/eNET.c - ----------------- - The driver is standard HW watchdog. Simple conversion is possible. - - - board/eltec/elppc/elppc.c - ------------------------- - The driver is standard HW watchdog. Simple conversion is possible. - - - board/enbw/enbw_cmc/enbw_cmc.c - ------------------------------ - Only function proxy call. Code cleanup needed. - - - board/freescale/mx31pdk/mx31pdk.c - --------------------------------- - Only function proxy call. Code cleanup needed. - - - board/gth2/gth2.c - ----------------- - The driver is standard HW watchdog. Simple conversion is possible. - - - board/lwmon5/lwmon5.c - --------------------- - The driver is standard HW watchdog. Simple conversion is possible. - - - board/manroland/mucmc52/mucmc52.c - --------------------------------- - The driver is standard HW watchdog. Simple conversion is possible. - - - board/manroland/uc101/uc101.c - ----------------------------- - The driver is standard HW watchdog. Simple conversion is possible. - - - board/mousse/m48t59y.c - ---------------------- - Special watchdog driver. Dead code. To be removed. - - - board/mvblue/mvblue.c - --------------------- - The driver is standard HW watchdog. Simple conversion is possible. - - - board/netphone/netphone.c - ------------------------- - The driver is standard HW watchdog. Simple conversion is possible. - - - board/netta/netta.c - ------------------- - The driver is standard HW watchdog. Simple conversion is possible. - - - board/netta2/netta2.c - --------------------- - The driver is standard HW watchdog. Simple conversion is possible. - - - board/omicron/calimain/calimain.c - --------------------------------- - Only function proxy call. Code cleanup needed. - - - board/pcs440ep/pcs440ep.c - ------------------------- - The driver is standard HW watchdog. Simple conversion is possible. - - - board/stx/stxxtc/stxxtc.c - ------------------------- - The driver is standard HW watchdog. Simple conversion is possible. - - - board/ti/omap2420h4/omap2420h4.c - -------------------------------- - The driver is standard HW watchdog. Simple conversion is possible. - - - board/ttcontrol/vision2/vision2.c - --------------------------------- - The driver is standard HW watchdog but namespace is polluted by - non-standard macros. Simple conversion is possible, code cleanup - needed. - - - board/v38b/v38b.c - ----------------- - The driver is standard HW watchdog. Simple conversion is possible. - - - board/ve8313/ve8313.c - --------------------- - The driver is standard HW watchdog. Simple conversion is possible. - - - board/w7o/watchdog.c - -------------------- - The driver is standard HW watchdog. Simple conversion is possible. |