mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-11-18 18:59:44 +00:00
42 lines
1.3 KiB
Text
42 lines
1.3 KiB
Text
|
New C structure AT91 SoC access
|
||
|
|
=================================
|
||
|
|
|
||
|
|
The goal
|
||
|
|
--------
|
||
|
|
|
||
|
|
Currently the at91 arch uses hundreds of address defines and special
|
||
|
|
at91_xxxx_write/read functions to access the SOC.
|
||
|
|
The u-boot project perferred method is to access memory mapped hw
|
||
|
|
regisister via a c structure.
|
||
|
|
|
||
|
|
e.g. old
|
||
|
|
|
||
|
|
*AT91C_PIOA_IDR = AT91_PMX_AA_TWD | AT91_PMX_AA_TWCK;
|
||
|
|
*AT91C_PIOC_PUDR = AT91_PMX_AA_TWD | AT91_PMX_AA_TWCK;
|
||
|
|
*AT91C_PIOC_PER = AT91_PMX_AA_TWD | AT91_PMX_AA_TWCK;
|
||
|
|
*AT91C_PIOC_OER = AT91_PMX_AA_TWD | AT91_PMX_AA_TWCK;
|
||
|
|
*AT91C_PIOC_PIO = AT91_PMX_AA_TWD | AT91_PMX_AA_TWCK;
|
||
|
|
|
||
|
|
at91_sys_write(AT91_RSTC_CR,
|
||
|
|
AT91_RSTC_KEY | AT91_RSTC_PROCRST | AT91_RSTC_PERRST);
|
||
|
|
|
||
|
|
e.g new
|
||
|
|
pin = AT91_PMX_AA_TWD | AT91_PMX_AA_TWCK;
|
||
|
|
writel(pin, &pio->pioa.idr);
|
||
|
|
writel(pin, &pio->pioa.pudr);
|
||
|
|
writel(pin, &pio->pioa.per);
|
||
|
|
writel(pin, &pio->pioa.oer);
|
||
|
|
writel(pin, &pio->pioa.sodr);
|
||
|
|
|
||
|
|
writel(AT91_RSTC_KEY | AT91_RSTC_CR_PROCRST |
|
||
|
|
AT91_RSTC_CR_PERRST, &rstc->cr);
|
||
|
|
|
||
|
|
The method for updating
|
||
|
|
------------------------
|
||
|
|
|
||
|
|
1. add's the temporary CONFIG_AT91_LEGACY to all at91 board configs
|
||
|
|
2. Display a compile time warning, if the board has not been converted
|
||
|
|
3. add new structures for SoC access
|
||
|
|
4. Convert arch, driver and boards file to new SoC
|
||
|
|
5. remove legacy code, if all boards and drives are ready
|