diff options
Diffstat (limited to 'Documentation/arm/Samsung-S3C24XX')
-rw-r--r-- | Documentation/arm/Samsung-S3C24XX/DMA.txt | 46 | ||||
-rw-r--r-- | Documentation/arm/Samsung-S3C24XX/Overview.txt | 21 | ||||
-rw-r--r-- | Documentation/arm/Samsung-S3C24XX/Suspend.txt | 35 |
3 files changed, 96 insertions, 6 deletions
diff --git a/Documentation/arm/Samsung-S3C24XX/DMA.txt b/Documentation/arm/Samsung-S3C24XX/DMA.txt new file mode 100644 index 000000000000..37f4edcc5d87 --- /dev/null +++ b/Documentation/arm/Samsung-S3C24XX/DMA.txt @@ -0,0 +1,46 @@ + S3C2410 DMA + =========== + +Introduction +------------ + + The kernel provides an interface to manage DMA transfers + using the DMA channels in the cpu, so that the central + duty of managing channel mappings, and programming the + channel generators is in one place. + + +DMA Channel Ordering +-------------------- + + Many of the range do not have connections for the DMA + channels to all sources, which means that some devices + have a restricted number of channels that can be used. + + To allow flexibilty for each cpu type and board, the + dma code can be given an dma ordering structure which + allows the order of channel search to be specified, as + well as allowing the prohibition of certain claims. + + struct s3c24xx_dma_order has a list of channels, and + each channel within has a slot for a list of dma + channel numbers. The slots are searched in order, for + the presence of a dma channel number with DMA_CH_VALID + orred in. + + If the order has the flag DMA_CH_NEVER set, then after + checking the channel list, the system will return no + found channel, thus denying the request. + + A board support file can call s3c24xx_dma_order_set() + to register an complete ordering set. The routine will + copy the data, so the original can be discared with + __initdata. + + +Authour +------- + +Ben Dooks, +Copyright (c) 2007 Ben Dooks, Simtec Electronics +Licensed under the GPL v2 diff --git a/Documentation/arm/Samsung-S3C24XX/Overview.txt b/Documentation/arm/Samsung-S3C24XX/Overview.txt index 28d014714ab8..c31b76fa66c4 100644 --- a/Documentation/arm/Samsung-S3C24XX/Overview.txt +++ b/Documentation/arm/Samsung-S3C24XX/Overview.txt @@ -8,13 +8,10 @@ Introduction The Samsung S3C24XX range of ARM9 System-on-Chip CPUs are supported by the 's3c2410' architecture of ARM Linux. Currently the S3C2410, - S3C2440 and S3C2442 devices are supported. + S3C2412, S3C2413, S3C2440 and S3C2442 devices are supported. Support for the S3C2400 series is in progress. - Support for the S3C2412 and S3C2413 CPUs is being merged. - - Configuration ------------- @@ -26,6 +23,22 @@ Configuration please check the machine specific documentation. +Layout +------ + + The core support files are located in the platform code contained in + arch/arm/plat-s3c24xx with headers in include/asm-arm/plat-s3c24xx. + This directory should be kept to items shared between the platform + code (arch/arm/plat-s3c24xx) and the arch/arm/mach-s3c24* code. + + Each cpu has a directory with the support files for it, and the + machines that carry the device. For example S3C2410 is contained + in arch/arm/mach-s3c2410 and S3C2440 in arch/arm/mach-s3c2440 + + Register, kernel and platform data definitions are held in the + include/asm-arm/arch-s3c2410 directory. + + Machines -------- diff --git a/Documentation/arm/Samsung-S3C24XX/Suspend.txt b/Documentation/arm/Samsung-S3C24XX/Suspend.txt index e12bc3284a27..0dab6e32c130 100644 --- a/Documentation/arm/Samsung-S3C24XX/Suspend.txt +++ b/Documentation/arm/Samsung-S3C24XX/Suspend.txt @@ -5,10 +5,10 @@ Introduction ------------ - The S3C2410 supports a low-power suspend mode, where the SDRAM is kept + The S3C24XX supports a low-power suspend mode, where the SDRAM is kept in Self-Refresh mode, and all but the essential peripheral blocks are powered down. For more information on how this works, please look - at the S3C2410 datasheets from Samsung. + at the relevant CPU datasheet from Samsung. Requirements @@ -56,6 +56,27 @@ Machine Support Note, the original method of adding an late_initcall() is wrong, and will end up initialising all compiled machines' pm init! + The following is an example of code used for testing wakeup from + an falling edge on IRQ_EINT0: + + +static irqreturn_t button_irq(int irq, void *pw) +{ + return IRQ_HANDLED; +} + +statuc void __init machine_init(void) +{ + ... + + request_irq(IRQ_EINT0, button_irq, IRQF_TRIGGER_FALLING, + "button-irq-eint0", NULL); + + enable_irq_wake(IRQ_EINT0); + + s3c2410_pm_init(); +} + Debugging --------- @@ -70,6 +91,12 @@ Debugging care should be taken that any external clock sources that the UARTs rely on are still enabled at that point. + 3) If any debugging is placed in the resume path, then it must have the + relevant clocks and peripherals setup before use (ie, bootloader). + + For example, if you transmit a character from the UART, the baud + rate and uart controls must be setup beforehand. + Configuration ------------- @@ -89,6 +116,10 @@ Configuration Allows the entire memory to be checksummed before and after the suspend to see if there has been any corruption of the contents. + Note, the time to calculate the CRC is dependant on the CPU speed + and the size of memory. For an 64Mbyte RAM area on an 200MHz + S3C2410, this can take approximately 4 seconds to complete. + This support requires the CRC32 function to be enabled. |