| /* |
| * (C) Copyright 2002 |
| * David Mueller, ELSOFT AG, d.mueller@elsoft.ch |
| * |
| * 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 |
| */ |
| |
| /* This code should work for both the S3C2400 and the S3C2410 |
| * as they seem to have the same I2C controller inside. |
| * The different address mapping is handled by the s3c24xx.h files below. |
| */ |
| |
| #include <common.h> |
| |
| #ifdef CONFIG_DRIVER_S3C24X0_I2C |
| |
| #if defined(CONFIG_S3C2400) |
| #include <s3c2400.h> |
| #elif defined(CONFIG_S3C2410) |
| #include <s3c2410.h> |
| #endif |
| #include <i2c.h> |
| |
| #ifdef CONFIG_HARD_I2C |
| |
| #define IIC_WRITE 0 |
| #define IIC_READ 1 |
| |
| #define IIC_OK 0 |
| #define IIC_NOK 1 |
| #define IIC_NACK 2 |
| #define IIC_NOK_LA 3 /* Lost arbitration */ |
| #define IIC_NOK_TOUT 4 /* time out */ |
| |
| #define IICSTAT_BSY 0x20 /* Busy bit */ |
| #define IICSTAT_NACK 0x01 /* Nack bit */ |
| #define IICCON_IRPND 0x10 /* Interrupt pending bit */ |
| #define IIC_MODE_MT 0xC0 /* Master Transmit Mode */ |
| #define IIC_MODE_MR 0x80 /* Master Receive Mode */ |
| #define IIC_START_STOP 0x20 /* START / STOP */ |
| #define IIC_TXRX_ENA 0x10 /* I2C Tx/Rx enable */ |
| |
| #define IIC_TIMEOUT 1 /* 1 seconde */ |
| |
| |
| static int GetIICSDA(void) |
| { |
| return (rGPEDAT & 0x8000) >> 15; |
| } |
| |
| static void SetIICSDA(int x) |
| { |
| rGPEDAT = (rGPEDAT & ~0x8000) | (x&1) << 15; |
| } |
| |
| static void SetIICSCL(int x) |
| { |
| rGPEDAT = (rGPEDAT & ~0x4000) | (x&1) << 14; |
| } |
| |
| |
| static int WaitForXfer(void) |
| { |
| int i, status; |
| |
| i = IIC_TIMEOUT * 1000; |
| status = rIICCON; |
| while ((i > 0) && !(status & IICCON_IRPND)) { |
| udelay(1000); |
| status = rIICCON; |
| i--; |
| } |
| |
| return(status & IICCON_IRPND) ? IIC_OK : IIC_NOK_TOUT; |
| } |
| |
| static int IsACK(void) |
| { |
| return(!(rIICSTAT & IICSTAT_NACK)); |
| } |
| |
| static void ReadWriteByte(void) |
| { |
| rIICCON &= ~IICCON_IRPND; |
| } |
| |
| void i2c_init (int speed, int slaveadd) |
| { |
| ulong freq, pres = 16, div; |
| int i, status; |
| |
| /* wait for some time to give previous transfer a chance to finish */ |
| |
| i = IIC_TIMEOUT * 1000; |
| status = rIICSTAT; |
| while ((i > 0) && (status & IICSTAT_BSY)) { |
| udelay(1000); |
| status = rIICSTAT; |
| i--; |
| } |
| |
| if ((status & IICSTAT_BSY) || GetIICSDA() == 0) { |
| ulong old_gpecon = rGPECON; |
| /* bus still busy probably by (most) previously interrupted transfer */ |
| |
| /* set IICSDA and IICSCL (GPE15, GPE14) to GPIO */ |
| rGPECON = (rGPECON & ~0xF0000000) | 0x10000000; |
| |
| /* toggle IICSCL until bus idle */ |
| SetIICSCL(0); udelay(1000); |
| i = 10; |
| while ((i > 0) && (GetIICSDA() != 1)) { |
| SetIICSCL(1); udelay(1000); |
| SetIICSCL(0); udelay(1000); |
| i--; |
| } |
| SetIICSCL(1); udelay(1000); |
| |
| /* restore pin functions */ |
| rGPECON = old_gpecon; |
| } |
| |
| /* calculate prescaler and divisor values */ |
| freq = get_PCLK(); |
| if ((freq / pres / (16+1)) > speed) |
| /* set prescaler to 512 */ |
| pres = 512; |
| |
| div = 0; |
| while ((freq / pres / (div+1)) > speed) |
| div++; |
| |
| /* set prescaler, divisor according to freq, also set |
| ACKGEN, IRQ */ |
| rIICCON = (div & 0x0F) | 0xA0 | ((pres == 512) ? 0x40 : 0); |
| |
| /* init to SLAVE REVEIVE and set slaveaddr */ |
| rIICSTAT = 0; |
| rIICADD = slaveadd; |
| /* program Master Transmit (and implicit STOP) */ |
| rIICSTAT = IIC_MODE_MT | IIC_TXRX_ENA; |
| |
| } |
| |
| /* |
| 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. |
| |
| */ |
| 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) |
| { |
| int i, status, result; |
| |
| 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; |
| } |
| |
| //CheckDelay(); |
| |
| /* Check I2C bus idle */ |
| i = IIC_TIMEOUT * 1000; |
| status = rIICSTAT; |
| while ((i > 0) && (status & IICSTAT_BSY)) { |
| udelay(1000); |
| status = rIICSTAT; |
| i--; |
| } |
| |
| |
| if (status & IICSTAT_BSY) { |
| result = IIC_NOK_TOUT; |
| return(result); |
| } |
| |
| rIICCON |= 0x80; |
| |
| result = IIC_OK; |
| |
| switch (cmd_type) { |
| case IIC_WRITE: |
| if (addr && addr_len) { |
| rIICDS = chip; |
| /* send START */ |
| rIICSTAT = IIC_MODE_MT | IIC_TXRX_ENA | IIC_START_STOP; |
| i = 0; |
| while ((i < addr_len) && (result == IIC_OK)) { |
| result = WaitForXfer(); |
| rIICDS = addr[i]; |
| ReadWriteByte(); |
| i++; |
| } |
| i = 0; |
| while ((i < data_len) && (result == IIC_OK)) { |
| result = WaitForXfer(); |
| rIICDS = data[i]; |
| ReadWriteByte(); |
| i++; |
| } |
| } else { |
| rIICDS = chip; |
| /* send START */ |
| rIICSTAT = IIC_MODE_MT | IIC_TXRX_ENA | IIC_START_STOP; |
| i = 0; |
| while ((i < data_len) && (result = IIC_OK)) { |
| result = WaitForXfer(); |
| rIICDS = data[i]; |
| ReadWriteByte(); |
| i++; |
| } |
| } |
| |
| if (result == IIC_OK) |
| result = WaitForXfer(); |
| |
| /* send STOP */ |
| rIICSTAT = IIC_MODE_MR | IIC_TXRX_ENA; |
| ReadWriteByte(); |
| break; |
| |
| case IIC_READ: |
| if (addr && addr_len) { |
| rIICSTAT = IIC_MODE_MT | IIC_TXRX_ENA; |
| rIICDS = chip; |
| /* send START */ |
| rIICSTAT |= IIC_START_STOP; |
| result = WaitForXfer(); |
| if (IsACK()) { |
| i = 0; |
| while ((i < addr_len) && (result == IIC_OK)) { |
| rIICDS = addr[i]; |
| ReadWriteByte(); |
| result = WaitForXfer(); |
| i++; |
| } |
| |
| rIICDS = chip; |
| /* resend START */ |
| rIICSTAT = IIC_MODE_MR | IIC_TXRX_ENA | IIC_START_STOP; |
| ReadWriteByte(); |
| result = WaitForXfer(); |
| i = 0; |
| while ((i < data_len) && (result == IIC_OK)) { |
| /* disable ACK for final READ */ |
| if (i == data_len - 1) |
| rIICCON &= ~0x80; |
| ReadWriteByte(); |
| result = WaitForXfer(); |
| data[i] = rIICDS; |
| i++; |
| } |
| } else { |
| result = IIC_NACK; |
| } |
| |
| } else { |
| rIICSTAT = IIC_MODE_MR | IIC_TXRX_ENA; |
| rIICDS = chip; |
| /* send START */ |
| rIICSTAT |= IIC_START_STOP; |
| result = WaitForXfer(); |
| |
| if (IsACK()) { |
| i = 0; |
| while ((i < data_len) && (result == IIC_OK)) { |
| /* disable ACK for final READ */ |
| if (i == data_len - 1) |
| rIICCON &= ~0x80; |
| ReadWriteByte(); |
| result = WaitForXfer(); |
| data[i] = rIICDS; |
| i++; |
| } |
| } else { |
| result = IIC_NACK; |
| } |
| } |
| |
| /* send STOP */ |
| rIICSTAT = IIC_MODE_MR | IIC_TXRX_ENA; |
| ReadWriteByte(); |
| break; |
| |
| default: |
| printf( "i2c_transfer: bad call\n" ); |
| result = IIC_NOK; |
| break; |
| } |
| |
| 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 (IIC_READ, chip << 1, 0, 0, buf, 1) != IIC_OK); |
| } |
| |
| 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(IIC_READ, 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(IIC_WRITE, chip<<1, &xaddr[4-alen], alen, buffer, len ) != 0); |
| } |
| |
| #endif /* CONFIG_HARD_I2C */ |
| |
| #endif /* CONFIG_DRIVER_S3C24X0_I2C */ |