diff options
Diffstat (limited to 'drivers/i2c/s3c44b0_i2c.c')
| -rw-r--r-- | drivers/i2c/s3c44b0_i2c.c | 315 |
1 files changed, 315 insertions, 0 deletions
diff --git a/drivers/i2c/s3c44b0_i2c.c b/drivers/i2c/s3c44b0_i2c.c new file mode 100644 index 0000000..b4d904b --- /dev/null +++ b/drivers/i2c/s3c44b0_i2c.c @@ -0,0 +1,315 @@ +/* + * (C) Copyright 2004 + * DAVE Srl + * http://www.dave-tech.it + * http://www.wawnet.biz + * mailto:info@wawnet.biz + * + * 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 <command.h> +#include <asm/hardware.h> + +/* + * Initialization, must be called once on start up, may be called + * repeatedly to change the speed and slave addresses. + */ +void i2c_init(int speed, int slaveaddr) +{ + /* + setting up I2C support + */ + unsigned int save_F,save_PF,rIICCON,rPCONA,rPDATA,rPCONF,rPUPF; + + save_F = PCONF; + save_PF = PUPF; + + rPCONF = ((save_F & ~(0xF))| 0xa); + rPUPF = (save_PF | 0x3); + PCONF = rPCONF; /*PF0:IICSCL, PF1:IICSDA*/ + PUPF = rPUPF; /* Disable pull-up */ + + /* Configuring pin for WC pin of EEprom */ + rPCONA = PCONA; + rPCONA &= ~(1<<9); + PCONA = rPCONA; + + rPDATA = PDATA; + rPDATA &= ~(1<<9); + PDATA = rPDATA; + + /* + Enable ACK, IICCLK=MCLK/16, enable interrupt + 75MHz/16/(12+1) = 390625 Hz + */ + rIICCON=(1<<7)|(0<<6)|(1<<5)|(0xC); + IICCON = rIICCON; + + IICADD = slaveaddr; +} + +/* + * Probe the given I2C chip address. Returns 0 if a chip responded, + * not 0 on failure. + */ +int i2c_probe(uchar chip) +{ + /* + not implemented + */ + + printf("i2c_probe chip %d\n", (int) chip); + return -1; +} + +/* + * Read/Write interface: + * chip: I2C chip address, range 0..127 + * addr: Memory (register) address within the chip + * alen: Number of bytes to use for addr (typically 1, 2 for larger + * memories, 0 for register type devices with only one + * register) + * buffer: Where to read/write the data + * len: How many bytes to read/write + * + * Returns: 0 on success, not 0 on failure + */ + +#define S3C44B0X_rIIC_INTPEND (1<<4) +#define S3C44B0X_rIIC_LAST_RECEIV_BIT (1<<0) +#define S3C44B0X_rIIC_INTERRUPT_ENABLE (1<<5) +#define S3C44B0_IIC_TIMEOUT 100 + +int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len) +{ + + int k, j, temp; + u32 rIICSTAT; + + /* + send the device offset + */ + + rIICSTAT = 0xD0; + IICSTAT = rIICSTAT; + + IICDS = chip; /* this is a write operation... */ + + rIICSTAT |= (1<<5); + IICSTAT = rIICSTAT; + + for(k=0; k<S3C44B0_IIC_TIMEOUT; k++) { + temp = IICCON; + if( (temp & S3C44B0X_rIIC_INTPEND) == S3C44B0X_rIIC_INTPEND) + break; + udelay(2000); + } + if (k==S3C44B0_IIC_TIMEOUT) + return -1; + + /* wait and check ACK */ + temp = IICSTAT; + if ((temp & S3C44B0X_rIIC_LAST_RECEIV_BIT) == S3C44B0X_rIIC_LAST_RECEIV_BIT ) + return -1; + + IICDS = addr; + IICCON = IICCON & ~(S3C44B0X_rIIC_INTPEND); + + /* wait and check ACK */ + for(k=0; k<S3C44B0_IIC_TIMEOUT; k++) { + temp = IICCON; + if( (temp & S3C44B0X_rIIC_INTPEND) == S3C44B0X_rIIC_INTPEND) + break; + udelay(2000); + } + if (k==S3C44B0_IIC_TIMEOUT) + return -1; + + temp = IICSTAT; + if ((temp & S3C44B0X_rIIC_LAST_RECEIV_BIT) == S3C44B0X_rIIC_LAST_RECEIV_BIT ) + return -1; + + /* + now we can start with the read operation... + */ + + IICDS = chip | 0x01; /* this is a read operation... */ + + rIICSTAT = 0x90; /*master recv*/ + rIICSTAT |= (1<<5); + IICSTAT = rIICSTAT; + + IICCON = IICCON & ~(S3C44B0X_rIIC_INTPEND); + + /* wait and check ACK */ + for(k=0; k<S3C44B0_IIC_TIMEOUT; k++) { + temp = IICCON; + if( (temp & S3C44B0X_rIIC_INTPEND) == S3C44B0X_rIIC_INTPEND) + break; + udelay(2000); + } + if (k==S3C44B0_IIC_TIMEOUT) + return -1; + + temp = IICSTAT; + if ((temp & S3C44B0X_rIIC_LAST_RECEIV_BIT) == S3C44B0X_rIIC_LAST_RECEIV_BIT ) + return -1; + + for (j=0; j<len-1; j++) { + + /*clear pending bit to resume */ + + temp = IICCON & ~(S3C44B0X_rIIC_INTPEND); + IICCON = temp; + + /* wait and check ACK */ + for(k=0; k<S3C44B0_IIC_TIMEOUT; k++) { + temp = IICCON; + if( (temp & S3C44B0X_rIIC_INTPEND) == S3C44B0X_rIIC_INTPEND) + break; + udelay(2000); + } + if (k==S3C44B0_IIC_TIMEOUT) + return -1; + + + buffer[j] = IICDS; /*save readed data*/ + + } /*end for(j)*/ + + /* + reading the last data + unset ACK generation + */ + temp = IICCON & ~(S3C44B0X_rIIC_INTPEND | (1<<7)); + IICCON = temp; + + /* wait but NOT check ACK */ + for(k=0; k<S3C44B0_IIC_TIMEOUT; k++) { + temp = IICCON; + if( (temp & S3C44B0X_rIIC_INTPEND) == S3C44B0X_rIIC_INTPEND) + break; + udelay(2000); + } + if (k==S3C44B0_IIC_TIMEOUT) + return -1; + + buffer[j] = IICDS; /*save readed data*/ + + rIICSTAT = 0x90; /*master recv*/ + + /* Write operation Terminate sending STOP */ + IICSTAT = rIICSTAT; + /*Clear Int Pending Bit to RESUME*/ + temp = IICCON; + IICCON = temp & (~S3C44B0X_rIIC_INTPEND); + + IICCON = IICCON | (1<<7); /*restore ACK generation*/ + + return 0; +} + +int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len) +{ + int j, k; + u32 rIICSTAT, temp; + + + /* + send the device offset + */ + + rIICSTAT = 0xD0; + IICSTAT = rIICSTAT; + + IICDS = chip; /* this is a write operation... */ + + rIICSTAT |= (1<<5); + IICSTAT = rIICSTAT; + + IICCON = IICCON & ~(S3C44B0X_rIIC_INTPEND); + + /* wait and check ACK */ + for(k=0; k<S3C44B0_IIC_TIMEOUT; k++) { + temp = IICCON; + if( (temp & S3C44B0X_rIIC_INTPEND) == S3C44B0X_rIIC_INTPEND) + break; + udelay(2000); + } + if (k==S3C44B0_IIC_TIMEOUT) + return -1; + + temp = IICSTAT; + if ((temp & S3C44B0X_rIIC_LAST_RECEIV_BIT) == S3C44B0X_rIIC_LAST_RECEIV_BIT ) + return -1; + + IICDS = addr; + IICCON = IICCON & ~(S3C44B0X_rIIC_INTPEND); + + /* wait and check ACK */ + for(k=0; k<S3C44B0_IIC_TIMEOUT; k++) { + temp = IICCON; + if( (temp & S3C44B0X_rIIC_INTPEND) == S3C44B0X_rIIC_INTPEND) + break; + udelay(2000); + } + if (k==S3C44B0_IIC_TIMEOUT) + return -1; + + temp = IICSTAT; + if ((temp & S3C44B0X_rIIC_LAST_RECEIV_BIT) == S3C44B0X_rIIC_LAST_RECEIV_BIT ) + return -1; + + /* + now we can start with the read write operation + */ + for (j=0; j<len; j++) { + + IICDS = buffer[j]; /*prerare data to write*/ + + /*clear pending bit to resume*/ + + temp = IICCON & ~(S3C44B0X_rIIC_INTPEND); + IICCON = temp; + + /* wait but NOT check ACK */ + for(k=0; k<S3C44B0_IIC_TIMEOUT; k++) { + temp = IICCON; + if( (temp & S3C44B0X_rIIC_INTPEND) == S3C44B0X_rIIC_INTPEND) + break; + + udelay(2000); + } + + if (k==S3C44B0_IIC_TIMEOUT) + return -1; + + } /* end for(j) */ + + /* sending stop to terminate */ + rIICSTAT = 0xD0; /*master send*/ + IICSTAT = rIICSTAT; + /*Clear Int Pending Bit to RESUME*/ + temp = IICCON; + IICCON = temp & (~S3C44B0X_rIIC_INTPEND); + + return 0; +} |