projects / people / ms / u-boot.git / blame
| Commit | Line | Data |
|---|---|---|
| 425de62d JS |
1 | New C structure AT91 SoC access |
| 2 | ================================= | |
| 3 | ||
| 4 | The goal | |
| 5 | -------- | |
| 6 | ||
| 7 | Currently the at91 arch uses hundreds of address defines and special | |
| 8 | at91_xxxx_write/read functions to access the SOC. | |
| 9 | The u-boot project perferred method is to access memory mapped hw | |
| 10 | regisister via a c structure. | |
| 11 | ||
| 12 | e.g. old | |
| 13 | ||
| 14 | *AT91C_PIOA_IDR = AT91_PMX_AA_TWD | AT91_PMX_AA_TWCK; | |
| 15 | *AT91C_PIOC_PUDR = AT91_PMX_AA_TWD | AT91_PMX_AA_TWCK; | |
| 16 | *AT91C_PIOC_PER = AT91_PMX_AA_TWD | AT91_PMX_AA_TWCK; | |
| 17 | *AT91C_PIOC_OER = AT91_PMX_AA_TWD | AT91_PMX_AA_TWCK; | |
| 18 | *AT91C_PIOC_PIO = AT91_PMX_AA_TWD | AT91_PMX_AA_TWCK; | |
| 19 | ||
| 20 | at91_sys_write(AT91_RSTC_CR, | |
| 21 | AT91_RSTC_KEY | AT91_RSTC_PROCRST | AT91_RSTC_PERRST); | |
| 22 | ||
| 23 | e.g new | |
| 24 | pin = AT91_PMX_AA_TWD | AT91_PMX_AA_TWCK; | |
| 25 | writel(pin, &pio->pioa.idr); | |
| 26 | writel(pin, &pio->pioa.pudr); | |
| 27 | writel(pin, &pio->pioa.per); | |
| 28 | writel(pin, &pio->pioa.oer); | |
| 29 | writel(pin, &pio->pioa.sodr); | |
| 30 | ||
| 31 | writel(AT91_RSTC_KEY | AT91_RSTC_CR_PROCRST | | |
| 32 | AT91_RSTC_CR_PERRST, &rstc->cr); | |
| 33 | ||
| 34 | The method for updating | |
| 35 | ------------------------ | |
| 36 | ||
| 37 | 1. add's the temporary CONFIG_AT91_LEGACY to all at91 board configs | |
| 38 | 2. Display a compile time warning, if the board has not been converted | |
| 39 | 3. add new structures for SoC access | |
| 40 | 4. Convert arch, driver and boards file to new SoC | |
| 41 | 5. remove legacy code, if all boards and drives are ready | |
| 98250e8e JS |
42 | |
| 43 | Join AT91 and AT91RM9200 SoC | |
| 44 | ============================== | |
| 45 | ||
| 46 | Approximately 95 percent of AT91 and AT91RM9200 SoC parts are the same. | |
| 47 | So, we should use the chance, to join both archs togetter. | |
| 48 | ||
| 49 | To do this follow step needed: | |
| 50 | ||
| 51 | 1. change Makefile | |
| 52 | @$(MKCONFIG) $(@:_config=) arm arm920t board vendor at91rm9200 | |
| 53 | to | |
| 54 | @$(MKCONFIG) $(@:_config=) arm arm920t board vendor at91 | |
| 55 | 2. remove CONFIG_AT91_LEGACY in board config | |
| 56 | 3. convert boards file to new SoC access | |
| 57 | 4. convert or change drivers | |
| 58 | ||
| 59 | To support the joining process, a new SoC dir (at91) has been adding to | |
| 60 | arm920t arch directory. This directory contains files like at91rm9200 dir, but | |
| 61 | uses the new c structure Soc access. The advantage of this is, we don't merge | |
| 62 | old Soc access code and new code while the board are not converted. | |
| 63 | Finally we can delete the whole at91rm9200 dir, if all board support the | |
| 64 | new AT91-SoC access. |