By the way, I keep seeing stuff like "C2" in PASM assembly in regard to the PRU's. Wish I could figure out what it is . . . Seems to be some sort of constant "register" ? And there is more than just C2, but I have not found any reference to those yet :/
On Sun, Nov 1, 2015 at 5:01 PM, William Hermans <[email protected]> wrote: > Hi Micka, > > I do not think he is using and driver. When speaking of the I2C module, I > believe hes speaking of the physical on chip module. But this . . . > > #define I2C1_BASE C2 //base registri I2C1 nella > tabella > > translated from Italian to English . . . *I2C1 base registers in the > table *which seems to me he is setting up the I2C hardware module > directly through it's registers in memory. But the other link, he pasted I > do not know if you saw it or not > http://beagleboard.org/Community/Forums/?place=msg%2Fbeagleboard%2FDAXyYJOrDIc%2FDZ8WKkRWaC0J > he talks about the problem being solved and he was not bringing the > hardware module out of reset, which is similar to how the ADC module works. > > Wish I could help you more, but I know nearly nothing about I2C. I know > what it is, and vaguely how it's done, but have never used I2C . . . > > On Sun, Nov 1, 2015 at 2:45 PM, Micka <[email protected]> wrote: > >> Hi, >> >> I'm interested by what you have done. I want to use i2c to read analog >> value from a component. >> >> The first solution that I found was to bitbang the i2c. But you, you use >> the i2c driver which is nice. >> >> Could you give us the peace of asm code that you use to interface with >> the MCP23017. And if you have the c code also it would be great. >> >> ( if possible, also the part of you managed to activate the module by >> writing MODULEMODE field into register CM_PER_I2C1_CLKCTRL register and >> also the code that wait for IDLEST field to confirm that module is ready). >> >> Micka, >> >> Le dim. 19 juil. 2015 21:45, Gianfranco Rosso < >> [email protected]> a écrit : >> >> I've also posted this in I2C topic, the solution is there: >> >> >> http://beagleboard.org/Community/Forums/?place=msg%2Fbeagleboard%2FDAXyYJOrDIc%2FDZ8WKkRWaC0J >> >> >> Il giorno lunedì 13 luglio 2015 09:49:20 UTC+2, Gianfranco Rosso ha >> scritto: >> >> I want to manage the I2C1 module by the PRU, in order to interface some >> I/O expanders (MCP23017 by Microchip). >> I use may own "cape" without the plug-n' play eeprom (one of the next >> steps will be adding management for DCAN0 and DCAN1 so i'll need these pins >> too...). >> So, at present, there are just 2 MCP23017 connected to the P9.17 and >> P9.18. >> >> I load the *cape-universal* into slots and then I use *configure-pin* >> command to set P9.17 and P9.18 as *i2c* >> >> I've started from an example into the *am335x_pru_package-master* and >> wrote my own C PRU loader. >> Very simple, it just: >> >> loads the PRU codeinit the data exhanged with the PRUstart the PRUwait >> for ESC key presssignal to the PRU to stopwait for the PRU stopexit. >> >> >> Also the assembly PRU code is simple: >> >> init I2C1 module (by writing registers PSC, SCLL, SCLH, CON)init 1st I/O >> expander as 16 inputs (even if at power on it's already set as input)init >> 2nd I/O expander as 16 outputscicle reading status of inputs from 1st >> expander and echoing to the outputs of 2nd expanderexit cycle and halt when >> receive stop flag from the loader >> >> for send and receive I2C messages I use register SA, CNT, DATA and CON. >> >> That's very simple and linear... pity, it doesn't work. >> >> *I didn't see any activity at all in P9.17 and P9.18*. >> >> The PRU code is surely running, as I add a cycle counter and show it in >> the loader while it's waiting for ESC keypress, and also the PRU code >> correctly stops at the loader command. >> >> I was expecting that the PRU code stalls if I2C bus doesn't work, as >> there are waiting cycles both for STOP condition or for CNT reaching zero >> (depending on the write or read message sending). >> >> But it seems running, and running very fast also: the cycle counter is >> incremented to a very fast rate (over 550 kcycles/s) that's not compatible >> with the correct executing of I2C sequences (I've setted the module for >> 400Kbps rate... so the PRU cycle it's even faster than a single I2C bit >> time!). >> >> I'm surely doing something wrong, but I cant fugure what. >> >> Any idea? >> >> Suggestions? >> >> Inserisci qui il codice... >> >> .origin 0 >> .entrypoint START >> >> #include "iic_ioexp.hp" >> >> //costanti per l'accesso al modulo I2C1 >> #define I2C1_BASE C2 //base registri I2C1 nella >> tabella costanti >> #define I2C_SYSC 0x10 //offset del registro I2C_SYSC >> #define I2C_STAT_RAW 0x24 //offset del registro >> I2C_STATUS_RAW >> #define I2C_SYSS 0x90 //offset del registro I2C_SYSS >> #define I2C_CNT 0x98 //offset del registro >> I2C_CNT >> #define I2C_DATA 0x9C //offset del registro I2C_DATA >> #define I2C_CON 0xA4 //offset del registro >> I2C_CON >> #define I2C_SA 0xAC //offset del registro I2C_SA >> #define I2C_PSC 0xB0 //offset del registro >> I2C_PSC >> #define I2C_SCLL 0xB4 //offset del registro I2C_SCLL >> #define I2C_SCLH 0xB8 //offset del registro I2C_SCLH >> >> #define I2C_CMD_ENABLE 0x8400 //modulo I2C abilitato >> come master >> #define I2C_CMD_TX 0x0200 //modulo I2C in >> trasmissione >> #define I2C_CMD_RX 0x0000 //modulo I2C in ricezione >> #define I2C_CMD_START 0x0001 //modulo I2C richiesta >> generazione sequenza START >> #define I2C_CMD_STOP 0x0002 //modulo I2C richiesta >> generazione sequenza STOP >> >> //costanti per l'accesso all'I/O expander MCP23017 >> #define IO_EXP0 0x20 //7bit I2C address >> dell'I/O expander 0 (ingressi) >> #define IO_EXP1 0x21 //7bit I2C address >> dell'I/O expander 1 (uscite) >> >> #define IO_EXP_IODIRA 0x00 //indirizzo registro IODIRA >> dell'I/O expander >> #define IO_EXP_GPIOA 0x12 //indirizzo registro GPIOA >> dell'I/O expander >> >> //====================================================================== >> >> //macro che attende fine sequenza verificando generazione seqeunza di STOP >> .macro I2C_WAIT_BY_STOP >> _CHECK: >> LBCO r1.w0, I2C1_BASE, I2C_CON, 2 >> QBBS _CHECK, r1.t1 >> .endm >> >> //macro che attende fine sequenza verificando generazione seqeunza di STOP >> .macro I2C_WAIT_BY_COUNT >> _CHECK: >> LBCO r1.w0, I2C1_BASE, I2C_CNT, 2 >> QBNE _CHECK, r1.w0, 0 >> .endm >> >> //====================================================================== >> >> START: >> // clear that bit >> LBCO r0, >> >> on >> >> , 4, 4 >> CLR r0, r0, 4 >> SBCO r0, C4, 4, 4 >> >> //------------------------------------------------------------------ >> //configurazione modulo I2C1 >> >> //reset del modulo I2C1 >> MOV r1.w0, 0x0002 >> SBCO r1.w0, I2C1_BASE, I2C_SYSC, 2 >> >> MOV r1.w0, 0x0000 >> SBCO r1.w0, I2C1_BASE, I2C_SYSC, 2 >> >> // //attesa fine reset modulo >> //_WAIT_RDONE: >> // LBCO r1, I2C1_BASE, I2C_SYSS, 4 >> // QBBC _WAIT_RDONE, r1.t0 >> >> //configura prescaler e durata SCL H/L per avere 400kHz >> MOV r1.b0, 4 //prescaler=4+1 --> >> ICLK=SCLK/prescaler=100/5=20MHz (nel reference manual raccomandano circa >> 24Mhz) >> SBCO r1.b0, I2C1_BASE, I2C_PSC, 1 >> >> MOV r1.b0, 18 //durata SCL L=18+7 --> >> tLOW=1/ICLK*(SCLL+7)=1/20E6*(18+7)=1.25us >> SBCO r1.b0, I2C1_BASE, I2C_SCLL, 1 >> >> MOV r1.b0, 20 //durata SCL H=20+5 --> >> tHIGH=1/ICLK*(SCLH+5)=1/20E6*(20+5)=1.25us >> SBCO r1.b0, I2C1_BASE, I2C_SCLH, 1 >> >> //abilita modulo >> MOV r1.w0, I2C_CMD_ENABLE >> SBCO r1.w0, I2C1_BASE, I2C_CON, 2 >> >> //------------------------------------------------------------------ >> //inizializzazione IOEXP 0 >> >> //indirizzo slave >> MOV r1.w0, IO_EXP0 >> SBCO r1.w0, I2C1_BASE, I2C_SA, 2 >> >> //n. byte da spedire >> MOV r1.w0, 3 >> SBCO r1.w0, I2C1_BASE, I2C_CNT, 2 >> >> //riempie FIFO >> MOV r1, IO_EXP_IODIRA | 0x00FFFF00 //tutti i pin come ingressi >> (in realta' e' gia' cosi' dal POR) >> SBCO r1.b0, I2C1_BASE, I2C_DATA, 1 >> SBCO r1.b1, I2C1_BASE, I2C_DATA, 1 >> SBCO r1.b2, I2C1_BASE, I2C_DATA, 1 >> >> //attesa bus free >> _WAIT_BB: >> LBCO r1, I2C1_BASE, I2C_STAT_RAW, 4 >> QBBS _WAIT_BB, r1.t12 >> >> //comando scrittura >> MOV r1.w0, I2C_CMD_ENABLE | I2C_CMD_TX | I2C_CMD_START | I2C_CMD_STOP >> SBCO r1.w0, I2C1_BASE, I2C_CON, 2 >> >> I2C_WAIT_BY_STOP >> >> //------------------------------------------------------------------ >> //inizializzazione IOEXP 1 >> >> //indirizzo slave >> MOV r1.w0, IO_EXP1 >> SBCO r1.w0, I2C1_BASE, I2C_SA, 2 >> >> //n. byte da spedire gia' impostato >> >> //riempie FIFO >> MOV r1, IO_EXP_IODIRA | 0x00000000 //tutti pin come uscita >> SBCO r1.b0, I2C1_BASE, I2C_DATA, 1 >> SBCO r1.b1, I2C1_BASE, I2C_DATA, 1 >> SBCO r1.b2, I2C1_BASE, I2C_DATA, 1 >> >> //comando scrittura >> MOV r1.w0, I2C_CMD_ENABLE | I2C_CMD_TX | I2C_CMD_START | I2C_CMD_STOP >> SBCO r1.w0, I2C1_BASE, I2C_CON, 2 >> >> I2C_WAIT_BY_STOP >> >> //------------------------------------------------------------------ >> //ciclo rinfresco I/O >> >> _LOOP: >> >> //------------------------------------------------------------------ >> //legge ingressi >> >> //indirizzo slave >> MOV r1.w0, IO_EXP0 >> SBCO r1.w0, I2C1_BASE, I2C_SA, 2 >> >> //n. byte da spedire >> MOV r1.w0, 1 >> SBCO r1.w0, I2C1_BASE, I2C_CNT, 2 >> >> //riempie FIFO >> MOV r1, IO_EXP_GPIOA >> SBCO r1.b0, I2C1_BASE, I2C_DATA, 1 >> >> //comando scrittura >> MOV r1.w0, I2C_CMD_ENABLE | I2C_CMD_TX | I2C_CMD_START >> SBCO r1.w0, I2C1_BASE, I2C_CON, 2 >> >> I2C_WAIT_BY_COUNT >> >> //n. byte da ricevere >> MOV r1.w0, 2 >> SBCO r1.w0, I2C1_BASE, I2C_CNT, 2 >> >> //comando lettura >> MOV r1.w0, I2C_CMD_ENABLE | I2C_CMD_RX | I2C_CMD_START | I2C_CMD_STOP >> SBCO r1.w0, I2C1_BASE, I2C_CON, 2 >> >> I2C_WAIT_BY_STOP >> >> //legge i byte ricevuti >> LBCO r2.b1, I2C1_BASE, I2C_DATA, 1 >> LBCO r2.b2, I2C1_BASE, I2C_DATA, 1 >> >> //------------------------------------------------------------------ >> //scrive uscite >> >> //indirizzo slave >> MOV r1.w0, IO_EXP1 >> SBCO r1.w0, I2C1_BASE, I2C_SA, 2 >> >> //n. byte da spedire >> MOV r1.w0, 3 >> SBCO r1.w0, I2C1_BASE, I2C_CNT, 2 >> >> //riempie FIFO >> MOV r2.b0, IO_EXP_GPIOA >> SBCO r2.b0, I2C1_BASE, I2C_DATA, 1 >> SBCO r2.b0, I2C1_BASE, I2C_DATA, 1 >> SBCO r2.b0, I2C1_BASE, I2C_DATA, 1 >> >> //comando scrittura >> MOV r1.w0, I2C_CMD_ENABLE | I2C_CMD_TX | I2C_CMD_START | I2C_CMD_STOP >> SBCO r1.w0, I2C1_BASE, I2C_CON, 2 >> >> I2C_WAIT_BY_STOP >> >> //------------------------------------------------------------------ >> LBCO r2, CONST_PRUDRAM, 0, 4 >> ADD r2, r2, 1 >> SBCO r2, CONST_PRUDRAM, 0, 4 >> >> //------------------------------------------------------------------ >> //esce dal ciclo e se il flag di uscita nella ram condivisa e' >> azzerato >> LBCO r2, CONST_PRUDRAM, 4, 1 >> QBNE _LOOP, r2.b0, 0 >> >> _EXIT: >> //invia all'host la notifica di programma completato >> MOV R31.b0, PRU0_ARM_INTERRUPT+16 >> >> HALT >> >> >> -- >> For more options, visit http://beagleboard.org/discuss >> --- >> You received this message because you are subscribed to the Google Groups >> "BeagleBoard" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> For more options, visit https://groups.google.com/d/optout. >> >> >> -- >> For more options, visit http://beagleboard.org/discuss >> --- >> You received this message because you are subscribed to the Google Groups >> "BeagleBoard" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> For more 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