FreeCalypso > hg > fc-magnetite
comparison doc/Leonardo-target @ 630:b639f7ab0007
Leonardo GPIO 2 fix
| author | Mychaela Falconia <falcon@freecalypso.org> |
|---|---|
| date | Fri, 03 Jan 2020 07:13:51 +0000 |
| parents | 41238a8e140c |
| children | 6edd9be81b94 |
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| 629:3231dd9b38c1 | 630:b639f7ab0007 |
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| 74 If you specify the build target as just leonardo, your fw will be configured | 74 If you specify the build target as just leonardo, your fw will be configured |
| 75 and built for the leonardo-dsp36 target. If you actually need leonardo-c05b or | 75 and built for the leonardo-dsp36 target. If you actually need leonardo-c05b or |
| 76 leonardo-dsp34 because your board has an older Calypso chip version on it, then | 76 leonardo-dsp34 because your board has an older Calypso chip version on it, then |
| 77 you will need to specify the build target as just stated - see the | 77 you will need to specify the build target as just stated - see the |
| 78 Calypso-version-override article. | 78 Calypso-version-override article. |
| 79 | |
| 80 Calypso GPIO 2 configuration | |
| 81 ============================ | |
| 82 | |
| 83 On TI's C-Sample and D-Sample boards Calypso GPIO 2 is wired to serve as the DCD | |
| 84 output for the MODEM UART (Calypso device as DCE), and our FC Magnetite firmware | |
| 85 drives it as such on D-Sample, FCDEV3B and GTM900 targets. But this same config | |
| 86 does NOT apply to Leonardo: on the latter boards GPIO 2 is wired in a way that | |
| 87 requires it to be configured as an input to Calypso, not an output. | |
| 88 | |
| 89 TI's TCS211 firmware had this Leonardo GPIO 2 situation handled in a very | |
| 90 bizarre manner: the main GPIO init code in AI_InitIOConfig() in armio.c made no | |
| 91 differentiation between D-Sample and Leonardo and configured GPIO 2 as an | |
| 92 output, then the init code in uartfax.c did the same setup again, but at the | |
| 93 end of the Init_Serial_Flows() function in the init module (which we only got | |
| 94 as init.obj, with init.c censored out) they inserted a bit of code that switches | |
| 95 GPIO 2 to be an input. What a mess. | |
| 96 | |
| 97 Our handling of this GPIO 2 situation in FC Magnetite is much cleaner: we have | |
| 98 put an #ifndef CONFIG_TARGET_LEONARDO around the AI_ConfigBitAsOutput(2) call | |
| 99 in AI_InitIOConfig() so this GPIO line never becomes an output in the first | |
| 100 place, and our targets/leonardo.h configuration header defines | |
| 101 UARTFAX_CLASSIC_DTR_DCD to 0 on this target, disabling that code in the | |
| 102 uartfax.c driver. | |
| 103 | |
| 104 Other GPIO and multifunction pins | |
| 105 ================================= | |
| 106 | |
| 107 Our Magnetite-Leonardo fw is unchanged from TI's TCS211 original in that GPIO0, | |
| 108 TSPDI/GPIO4 and DSR_MODEM/LPG pins are left configured as inputs, even though | |
| 109 the schematics we've got show GPIO0 as an output and the other two pins as | |
| 110 unconnected, in which case they should also be configured as outputs in order | |
| 111 to not float. We are leaving this aspect unchanged currently because this | |
| 112 Magnetite-Leonardo fw build target is really just a reference for practically | |
| 113 non-existent hw, and given the unknown of what other Leonardo variants may have | |
| 114 existed once beyond our known schematics, we would rather leave a few floating | |
| 115 inputs than risk causing a driver conflict on some unknown board. |