diff options
Diffstat (limited to 'cpu/ppc4xx/i2c.c')
| -rw-r--r-- | cpu/ppc4xx/i2c.c | 417 |
1 files changed, 417 insertions, 0 deletions
diff --git a/cpu/ppc4xx/i2c.c b/cpu/ppc4xx/i2c.c new file mode 100644 index 0000000000..68af057d1e --- /dev/null +++ b/cpu/ppc4xx/i2c.c @@ -0,0 +1,417 @@ +/*****************************************************************************/ +/* I2C Bus interface initialisation and I2C Commands */ +/* for PPC405GP */ +/* Author : AS HARNOIS */ +/* Date : 13.Dec.00 */ +/*****************************************************************************/ + +#include <common.h> +#include <ppc4xx.h> +#if defined(CONFIG_440) +# include <440_i2c.h> +#else +# include <405gp_i2c.h> +#endif +#include <i2c.h> + +#ifdef CONFIG_HARD_I2C + +#define IIC_OK 0 +#define IIC_NOK 1 +#define IIC_NOK_LA 2 /* Lost arbitration */ +#define IIC_NOK_ICT 3 /* Incomplete transfer */ +#define IIC_NOK_XFRA 4 /* Transfer aborted */ +#define IIC_NOK_DATA 5 /* No data in buffer */ +#define IIC_NOK_TOUT 6 /* Transfer timeout */ + +#define IIC_TIMEOUT 1 /* 1 seconde */ + + +static void _i2c_bus_reset (void) +{ + int i, status; + + /* Reset status register */ + /* write 1 in SCMP and IRQA to clear these fields */ + out8 (IIC_STS, 0x0A); + + /* write 1 in IRQP IRQD LA ICT XFRA to clear these fields */ + out8 (IIC_EXTSTS, 0x8F); + __asm__ volatile ("eieio"); + + /* + * Get current state, reset bus + * only if no transfers are pending. + */ + i = 10; + do { + /* Get status */ + status = in8 (IIC_STS); + udelay (500); /* 500us */ + i--; + } while ((status & IIC_STS_PT) && (i > 0)); + /* Soft reset controller */ + status = in8 (IIC_XTCNTLSS); + out8 (IIC_XTCNTLSS, (status | IIC_XTCNTLSS_SRST)); + __asm__ volatile ("eieio"); + + /* make sure where in initial state, data hi, clock hi */ + out8 (IIC_DIRECTCNTL, 0xC); + for (i = 0; i < 10; i++) { + if ((in8 (IIC_DIRECTCNTL) & 0x3) != 0x3) { + /* clock until we get to known state */ + out8 (IIC_DIRECTCNTL, 0x8); /* clock lo */ + udelay (100); /* 100us */ + out8 (IIC_DIRECTCNTL, 0xC); /* clock hi */ + udelay (100); /* 100us */ + } else { + break; + } + } + /* send start condition */ + out8 (IIC_DIRECTCNTL, 0x4); + udelay (1000); /* 1ms */ + /* send stop condition */ + out8 (IIC_DIRECTCNTL, 0xC); + udelay (1000); /* 1ms */ + /* Unreset controller */ + out8 (IIC_XTCNTLSS, (status & ~IIC_XTCNTLSS_SRST)); + udelay (1000); /* 1ms */ +} + +void i2c_init (int speed, int slaveadd) +{ + sys_info_t sysInfo; + unsigned long freqOPB; + int val, divisor; + + /* Handle possible failed I2C state */ + _i2c_bus_reset (); + + /* clear lo master address */ + out8 (IIC_LMADR, 0); + + /* clear hi master address */ + out8 (IIC_HMADR, 0); + + /* clear lo slave address */ + out8 (IIC_LSADR, 0); + + /* clear hi slave address */ + out8 (IIC_HSADR, 0); + + /* Clock divide Register */ + /* get OPB frequency */ + get_sys_info (&sysInfo); + freqOPB = sysInfo.freqPLB / sysInfo.pllOpbDiv; + /* set divisor according to freqOPB */ + divisor = (freqOPB - 1) / 10000000; + if (divisor == 0) + divisor = 1; + out8 (IIC_CLKDIV, divisor); + + /* no interrupts */ + out8 (IIC_INTRMSK, 0); + + /* clear transfer count */ + out8 (IIC_XFRCNT, 0); + + /* clear extended control & stat */ + /* write 1 in SRC SRS SWC SWS to clear these fields */ + out8 (IIC_XTCNTLSS, 0xF0); + + /* Mode Control Register + Flush Slave/Master data buffer */ + out8 (IIC_MDCNTL, IIC_MDCNTL_FSDB | IIC_MDCNTL_FMDB); + __asm__ volatile ("eieio"); + + + val = in8(IIC_MDCNTL); + __asm__ volatile ("eieio"); + + /* Ignore General Call, slave transfers are ignored, + disable interrupts, exit unknown bus state, enable hold + SCL + 100kHz normaly or FastMode for 400kHz and above + */ + + val |= IIC_MDCNTL_EUBS|IIC_MDCNTL_HSCL; + if( speed >= 400000 ){ + val |= IIC_MDCNTL_FSM; + } + out8 (IIC_MDCNTL, val); + + /* clear control reg */ + out8 (IIC_CNTL, 0x00); + __asm__ volatile ("eieio"); + +} + +/* + This code tries to use the features of the 405GP i2c + controller. It will transfer up to 4 bytes in one pass + on the loop. It only does out8(lbz) to the buffer when it + is possible to do out16(lhz) transfers. + + cmd_type is 0 for write 1 for read. + + addr_len can take any value from 0-255, it is only limited + by the char, we could make it larger if needed. If it is + 0 we skip the address write cycle. + + Typical case is a Write of an addr followd by a Read. The + IBM FAQ does not cover this. On the last byte of the write + we don't set the creg CHT bit, and on the first bytes of the + read we set the RPST bit. + + It does not support address only transfers, there must be + a data part. If you want to write the address yourself, put + it in the data pointer. + + It does not support transfer to/from address 0. + + It does not check XFRCNT. +*/ +static +int i2c_transfer(unsigned char cmd_type, + unsigned char chip, + unsigned char addr[], + unsigned char addr_len, + unsigned char data[], + unsigned short data_len ) +{ + unsigned char* ptr; + int reading; + int tran,cnt; + int result; + int status; + int i; + uchar creg; + + if( data == 0 || data_len == 0 ){ + /*Don't support data transfer of no length or to address 0*/ + printf( "i2c_transfer: bad call\n" ); + return IIC_NOK; + } + if( addr && addr_len ){ + ptr = addr; + cnt = addr_len; + reading = 0; + }else{ + ptr = data; + cnt = data_len; + reading = cmd_type; + } + + /*Clear Stop Complete Bit*/ + out8(IIC_STS,IIC_STS_SCMP); + /* Check init */ + i=10; + do { + /* Get status */ + status = in8(IIC_STS); + __asm__ volatile("eieio"); + i--; + } while ((status & IIC_STS_PT) && (i>0)); + + if (status & IIC_STS_PT) { + result = IIC_NOK_TOUT; + return(result); + } + /*flush the Master/Slave Databuffers*/ + out8(IIC_MDCNTL, ((in8(IIC_MDCNTL))|IIC_MDCNTL_FMDB|IIC_MDCNTL_FSDB)); + /*need to wait 4 OPB clocks? code below should take that long*/ + + /* 7-bit adressing */ + out8(IIC_HMADR,0); + out8(IIC_LMADR, chip); + __asm__ volatile("eieio"); + + tran = 0; + result = IIC_OK; + creg = 0; + + while ( tran != cnt && (result == IIC_OK)) { + int bc,j; + + /* Control register = + Normal transfer, 7-bits adressing, Transfer up to bc bytes, Normal start, + Transfer is a sequence of transfers + */ + creg |= IIC_CNTL_PT; + + bc = (cnt - tran) > 4 ? 4 : + cnt - tran; + creg |= (bc-1)<<4; + /* if the real cmd type is write continue trans*/ + if ( (!cmd_type && (ptr == addr)) || ((tran+bc) != cnt) ) + creg |= IIC_CNTL_CHT; + + if (reading) + creg |= IIC_CNTL_READ; + else { + for(j=0; j<bc; j++) { + /* Set buffer */ + out8(IIC_MDBUF,ptr[tran+j]); + __asm__ volatile("eieio"); + } + } + out8(IIC_CNTL, creg ); + __asm__ volatile("eieio"); + + /* Transfer is in progress + we have to wait for upto 5 bytes of data + 1 byte chip address+r/w bit then bc bytes + of data. + udelay(10) is 1 bit time at 100khz + Doubled for slop. 20 is too small. + */ + i=2*5*8; + do { + /* Get status */ + status = in8(IIC_STS); + __asm__ volatile("eieio"); + udelay (10); + i--; + } while ((status & IIC_STS_PT) && !(status & IIC_STS_ERR) + && (i>0)); + + if (status & IIC_STS_ERR) { + result = IIC_NOK; + status = in8 (IIC_EXTSTS); + /* Lost arbitration? */ + if (status & IIC_EXTSTS_LA) + result = IIC_NOK_LA; + /* Incomplete transfer? */ + if (status & IIC_EXTSTS_ICT) + result = IIC_NOK_ICT; + /* Transfer aborted? */ + if (status & IIC_EXTSTS_XFRA) + result = IIC_NOK_XFRA; + } else if ( status & IIC_STS_PT) { + result = IIC_NOK_TOUT; + } + /* Command is reading => get buffer */ + if ((reading) && (result == IIC_OK)) { + /* Are there data in buffer */ + if (status & IIC_STS_MDBS) { + /* + even if we have data we have to wait 4OPB clocks + for it to hit the front of the FIFO, after that + we can just read. We should check XFCNT here and + if the FIFO is full there is no need to wait. + */ + udelay (1); + for(j=0;j<bc;j++) { + ptr[tran+j] = in8(IIC_MDBUF); + __asm__ volatile("eieio"); + } + } else + result = IIC_NOK_DATA; + } + creg = 0; + tran+=bc; + if( ptr == addr && tran == cnt ) { + ptr = data; + cnt = data_len; + tran = 0; + reading = cmd_type; + if( reading ) + creg = IIC_CNTL_RPST; + } + } + return (result); +} + +int i2c_probe (uchar chip) +{ + uchar buf[1]; + + buf[0] = 0; + + /* + * What is needed is to send the chip address and verify that the + * address was <ACK>ed (i.e. there was a chip at that address which + * drove the data line low). + */ + return(i2c_transfer (1, chip << 1, 0,0, buf, 1) != 0); +} + + + +int i2c_read (uchar chip, uint addr, int alen, uchar * buffer, int len) +{ + uchar xaddr[4]; + int ret; + + if ( alen > 4 ) { + printf ("I2C read: addr len %d not supported\n", alen); + return 1; + } + + if ( alen > 0 ) { + xaddr[0] = (addr >> 24) & 0xFF; + xaddr[1] = (addr >> 16) & 0xFF; + xaddr[2] = (addr >> 8) & 0xFF; + xaddr[3] = addr & 0xFF; + } + + +#ifdef CFG_I2C_EEPROM_ADDR_OVERFLOW + /* + * EEPROM chips that implement "address overflow" are ones + * like Catalyst 24WC04/08/16 which has 9/10/11 bits of + * address and the extra bits end up in the "chip address" + * bit slots. This makes a 24WC08 (1Kbyte) chip look like + * four 256 byte chips. + * + * Note that we consider the length of the address field to + * still be one byte because the extra address bits are + * hidden in the chip address. + */ + if( alen > 0 ) + chip |= ((addr >> (alen * 8)) & CFG_I2C_EEPROM_ADDR_OVERFLOW); +#endif + if( (ret = i2c_transfer( 1, chip<<1, &xaddr[4-alen], alen, buffer, len )) != 0) { + printf( "I2c read: failed %d\n", ret); + return 1; + } + return 0; +} + +int i2c_write (uchar chip, uint addr, int alen, uchar * buffer, int len) +{ + uchar xaddr[4]; + + if ( alen > 4 ) { + printf ("I2C write: addr len %d not supported\n", alen); + return 1; + + } + if ( alen > 0 ) { + xaddr[0] = (addr >> 24) & 0xFF; + xaddr[1] = (addr >> 16) & 0xFF; + xaddr[2] = (addr >> 8) & 0xFF; + xaddr[3] = addr & 0xFF; + } + +#ifdef CFG_I2C_EEPROM_ADDR_OVERFLOW + /* + * EEPROM chips that implement "address overflow" are ones + * like Catalyst 24WC04/08/16 which has 9/10/11 bits of + * address and the extra bits end up in the "chip address" + * bit slots. This makes a 24WC08 (1Kbyte) chip look like + * four 256 byte chips. + * + * Note that we consider the length of the address field to + * still be one byte because the extra address bits are + * hidden in the chip address. + */ + if( alen > 0 ) + chip |= ((addr >> (alen * 8)) & CFG_I2C_EEPROM_ADDR_OVERFLOW); +#endif + + return (i2c_transfer( 0, chip<<1, &xaddr[4-alen], alen, buffer, len ) != 0); +} + +#endif /* CONFIG_HARD_I2C */ |