diff options
Diffstat (limited to 'u-boot/drivers/i2c/ppc4xx_i2c.c')
| -rw-r--r-- | u-boot/drivers/i2c/ppc4xx_i2c.c | 439 |
1 files changed, 439 insertions, 0 deletions
diff --git a/u-boot/drivers/i2c/ppc4xx_i2c.c b/u-boot/drivers/i2c/ppc4xx_i2c.c new file mode 100644 index 0000000..c1cbe55 --- /dev/null +++ b/u-boot/drivers/i2c/ppc4xx_i2c.c @@ -0,0 +1,439 @@ +/* + * (C) Copyright 2007-2009 + * Stefan Roese, DENX Software Engineering, sr@denx.de. + * + * based on work by Anne Sophie Harnois <anne-sophie.harnois@nextream.fr> + * + * (C) Copyright 2001 + * Bill Hunter, Wave 7 Optics, williamhunter@mediaone.net + * + * See file CREDITS for list of people who contributed to this + * project. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ + +#include <common.h> +#include <asm/ppc4xx.h> +#include <asm/ppc4xx-i2c.h> +#include <i2c.h> +#include <asm/io.h> + +#ifdef CONFIG_HARD_I2C + +DECLARE_GLOBAL_DATA_PTR; + +#if defined(CONFIG_I2C_MULTI_BUS) +/* + * Initialize the bus pointer to whatever one the SPD EEPROM is on. + * Default is bus 0. This is necessary because the DDR initialization + * runs from ROM, and we can't switch buses because we can't modify + * the global variables. + */ +#ifndef CONFIG_SYS_SPD_BUS_NUM +#define CONFIG_SYS_SPD_BUS_NUM 0 +#endif +static unsigned int i2c_bus_num __attribute__ ((section (".data"))) = + CONFIG_SYS_SPD_BUS_NUM; +#endif /* CONFIG_I2C_MULTI_BUS */ + +static void _i2c_bus_reset(void) +{ + struct ppc4xx_i2c *i2c = (struct ppc4xx_i2c *)I2C_BASE_ADDR; + int i; + u8 dc; + + /* Reset status register */ + /* write 1 in SCMP and IRQA to clear these fields */ + out_8(&i2c->sts, 0x0A); + + /* write 1 in IRQP IRQD LA ICT XFRA to clear these fields */ + out_8(&i2c->extsts, 0x8F); + + /* Place chip in the reset state */ + out_8(&i2c->xtcntlss, IIC_XTCNTLSS_SRST); + + /* Check if bus is free */ + dc = in_8(&i2c->directcntl); + if (!DIRCTNL_FREE(dc)){ + /* Try to set bus free state */ + out_8(&i2c->directcntl, IIC_DIRCNTL_SDAC | IIC_DIRCNTL_SCC); + + /* Wait until we regain bus control */ + for (i = 0; i < 100; ++i) { + dc = in_8(&i2c->directcntl); + if (DIRCTNL_FREE(dc)) + break; + + /* Toggle SCL line */ + dc ^= IIC_DIRCNTL_SCC; + out_8(&i2c->directcntl, dc); + udelay(10); + dc ^= IIC_DIRCNTL_SCC; + out_8(&i2c->directcntl, dc); + } + } + + /* Remove reset */ + out_8(&i2c->xtcntlss, 0); +} + +void i2c_init(int speed, int slaveaddr) +{ + struct ppc4xx_i2c *i2c; + int val, divisor; + int bus; + +#ifdef CONFIG_SYS_I2C_INIT_BOARD + /* + * Call board specific i2c bus reset routine before accessing the + * environment, which might be in a chip on that bus. For details + * about this problem see doc/I2C_Edge_Conditions. + */ + i2c_init_board(); +#endif + + for (bus = 0; bus < CONFIG_SYS_MAX_I2C_BUS; bus++) { + I2C_SET_BUS(bus); + + /* Set i2c pointer after calling I2C_SET_BUS() */ + i2c = (struct ppc4xx_i2c *)I2C_BASE_ADDR; + + /* Handle possible failed I2C state */ + /* FIXME: put this into i2c_init_board()? */ + _i2c_bus_reset(); + + /* clear lo master address */ + out_8(&i2c->lmadr, 0); + + /* clear hi master address */ + out_8(&i2c->hmadr, 0); + + /* clear lo slave address */ + out_8(&i2c->lsadr, 0); + + /* clear hi slave address */ + out_8(&i2c->hsadr, 0); + + /* Clock divide Register */ + /* set divisor according to freq_opb */ + divisor = (get_OPB_freq() - 1) / 10000000; + if (divisor == 0) + divisor = 1; + out_8(&i2c->clkdiv, divisor); + + /* no interrupts */ + out_8(&i2c->intrmsk, 0); + + /* clear transfer count */ + out_8(&i2c->xfrcnt, 0); + + /* clear extended control & stat */ + /* write 1 in SRC SRS SWC SWS to clear these fields */ + out_8(&i2c->xtcntlss, 0xF0); + + /* Mode Control Register + Flush Slave/Master data buffer */ + out_8(&i2c->mdcntl, IIC_MDCNTL_FSDB | IIC_MDCNTL_FMDB); + + val = in_8(&i2c->mdcntl); + + /* 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; + out_8(&i2c->mdcntl, val); + + /* clear control reg */ + out_8(&i2c->cntl, 0x00); + } + + /* set to SPD bus as default bus upon powerup */ + I2C_SET_BUS(CONFIG_SYS_SPD_BUS_NUM); +} + +/* + * 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 out_8((u8 *)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) +{ + struct ppc4xx_i2c *i2c = (struct ppc4xx_i2c *)I2C_BASE_ADDR; + u8 *ptr; + int reading; + int tran, cnt; + int result; + int status; + int i; + u8 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 */ + out_8(&i2c->sts, IIC_STS_SCMP); + + /* Check init */ + i = 10; + do { + /* Get status */ + status = in_8(&i2c->sts); + i--; + } while ((status & IIC_STS_PT) && (i > 0)); + + if (status & IIC_STS_PT) { + result = IIC_NOK_TOUT; + return(result); + } + + /* flush the Master/Slave Databuffers */ + out_8(&i2c->mdcntl, in_8(&i2c->mdcntl) | + IIC_MDCNTL_FMDB | IIC_MDCNTL_FSDB); + + /* need to wait 4 OPB clocks? code below should take that long */ + + /* 7-bit adressing */ + out_8(&i2c->hmadr, 0); + out_8(&i2c->lmadr, chip); + + 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 */ + out_8(&i2c->mdbuf, ptr[tran + j]); + } + } + out_8(&i2c->cntl, creg); + + /* + * 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 = in_8(&i2c->sts); + udelay(10); + i--; + } while ((status & IIC_STS_PT) && !(status & IIC_STS_ERR) && + (i > 0)); + + if (status & IIC_STS_ERR) { + result = IIC_NOK; + status = in_8(&i2c->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] = in_8(&i2c->mdbuf); + } 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); +} + +static int ppc4xx_i2c_transfer(uchar chip, uint addr, int alen, uchar *buffer, + int len, int read) +{ + uchar xaddr[4]; + int ret; + + if (alen > 4) { + printf("I2C: 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 CONFIG_SYS_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)) & + CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW); +#endif + if ((ret = i2c_transfer(read, chip << 1, &xaddr[4 - alen], alen, + buffer, len)) != 0) { + if (gd->have_console) { + printf("I2C %s: failed %d\n", + read ? "read" : "write", ret); + } + + return 1; + } + + return 0; +} + +int i2c_read(uchar chip, uint addr, int alen, uchar * buffer, int len) +{ + return ppc4xx_i2c_transfer(chip, addr, alen, buffer, len, 1); +} + +int i2c_write(uchar chip, uint addr, int alen, uchar * buffer, int len) +{ + return ppc4xx_i2c_transfer(chip, addr, alen, buffer, len, 0); +} + +#if defined(CONFIG_I2C_MULTI_BUS) +/* + * Functions for multiple I2C bus handling + */ +unsigned int i2c_get_bus_num(void) +{ + return i2c_bus_num; +} + +int i2c_set_bus_num(unsigned int bus) +{ + if (bus >= CONFIG_SYS_MAX_I2C_BUS) + return -1; + + i2c_bus_num = bus; + + return 0; +} +#endif /* CONFIG_I2C_MULTI_BUS */ +#endif /* CONFIG_HARD_I2C */ |