Did you have dts entries for IIC in device tree ? also did you have I2C enabled in "make menuconfig" "device drivers -> i2c support --> I2C bus support -> IBM ppc 4xx On chip I2C support " selected. Then you should i2c see an entry /proc/devices . Use that major address and create a device node "mknode /dev/i2c-0 c 89 0" . Write a user level program to access this device. Here is an example user code. ---------- cat fan.c /* This program is an example of writing and reading an EEPROM device via SMBus on a GE Fanuc Embedded Systems, Inc. VMIVME-7809 Single Board Computer. To compile this program: gcc -O vmieep.c -o vmieep
Before running this program, log in as root, then load the following modules using: /sbin/modprobe i2c-core /sbin/modprobe i2c-dev /sbin/modprobe i2c-i801 Loading the i2c-i801 module will create /dev/i2c-0, with permissions = CRW- --- ---. Either run the vmieep program as root, or change the permissions to CRW- RW- RW- as shown: chmod 666 /dev/i2c-0 */ #include <stdio.h> #include <string.h> #include <stdlib.h> #include <errno.h> #include <fcntl.h> //#include <linux/i2c.h> //#include <linux/i2c-dev.h> #include <sys/time.h> /* The inline smbus function definitions may or may not be in i2c-dev.h, depending on the Linux distribution. Comment or uncomment the following #include as necessary. */ #include "i2c-dev.h" /* Use the file of lm_sensors */ #define EEPROM_SIZE 256 /* Adjust for actual number of bytes in EEPROM */ #define EEPROM_SMBUS_ADDR 0x90 /* Do NOT change! */ int gef_eeprom_read(int fd, unsigned char start_offset, unsigned char *buffer, unsigned short buflen); int gef_eeprom_write(int fd, unsigned char start_offset, unsigned char *buffer, unsigned short buflen); void gef_msec_delay(unsigned int msecs); int main(int argc, char *argv[]) { int fd; /* File descriptor initialized with open() */ int adapter_num = 0; int status; char filename[20]; /* Name of special device file */ int i2c_addr = EEPROM_SMBUS_ADDR; /* SMBus address of EEPROM */ unsigned short offset; /* Which byte to access in the EEPROM */ unsigned char rbuffer; /* Data read from EEPROM */ if ((argc < 3) || (argc > 4)) { printf("Usage: fan read <addr> or fan write <addr> <data>\n"); return 0; } /* Open the special device file for the SMBus */ sprintf(filename, "/dev/i2c-%d", adapter_num); fd = open(filename, O_RDWR); if (fd < 0) { printf("ERROR: open(%s) failed\n", filename); printf("errno = %d, %s\n", errno, strerror(errno)); return -1; } //printf("SUCCESS: open(%s) passed\n", filename); /* Specify the EEPROM as the device we want to access. *** IMPORTANT *** The address is actually in the 7 LSBs, so shift i2c_addr one bit to the right.*/ status = ioctl(fd, I2C_SLAVE, i2c_addr>>1); if (status < 0) { printf("ERROR: ioctl(fd, I2C_SLAVE, 0x%02X) failed\n", i2c_addr); printf("errno = %d, %s\n", errno, strerror(errno)); close(fd); return -1; } //printf("SUCCESS: ioctl(fd, I2C_SLAVE, 0x%02X>>1) passed\n", i2c_addr); if (strcmp(argv[1],"read") == 0) { offset = atoi(argv[2]); gef_eeprom_read(fd, offset, &rbuffer, 1); printf("Offset: %d Data: %d\n", offset, rbuffer); } if (strcmp(argv[1],"write") == 0) { offset = (unsigned char)(atoi(argv[2])); rbuffer =(unsigned char)(atoi(argv[3])); gef_eeprom_write(fd, offset, &rbuffer, 1); printf("Offset: %d Data: %d\n", offset, rbuffer); } /* Close the special device file */ close(fd); return 0; } ////////////////////////////////////////////////////////////////////////////// // // Function name : gef_eeprom_read // // Description : Read buflen bytes from the EEPROM beginning at start_offset // // Return type : 0 for success, -1 for failure // // Argument : int fd : File descriptor returned by open() // Argument : unsigned char start_offset : Read bytes starting at this // offset in the EEPROM. The sum of buflen and // start_offset must not exceed the maximum size in bytes // of the EEPROM // Argument : unsigned char *buffer : Where to store the bytes read // from the EEPROM. The buffer must be large enough // to store buflen bytes read from the EEPROM. // Argument : unsigned short buflen : The size in bytes of buffer, or // how many bytes to read from the EEPROM. The sum of // buflen and start_offset must not exceed the maximum // size in bytes of the EEPROM. // int gef_eeprom_read(int fd, unsigned char start_offset, unsigned char *buffer, unsigned short buflen) { int offset, index; int data; for (index=0, offset=start_offset; index<buflen && offset<EEPROM_SIZE; index++, offset++) { data = i2c_smbus_read_byte_data(fd, offset); if (data == -1) { printf("ERROR: i2c_smbus_read_byte_data(fd, 0x%02X) failed\n", offset); printf("errno = %d, %s\n", errno, strerror(errno)); return -1; } buffer[index] = (unsigned char) (data); } return 0; } ////////////////////////////////////////////////////////////////////////////// // // Function name : gef_eeprom_write // // Description : Write buflen bytes to the EEPROM beginning at start_offset // // Return type : 0 for success, -1 for failure // // Argument : int fd : File descriptor returned by open() // Argument : unsigned char start_offset : Write bytes starting at this // offset in the EEPROM. The sum of buflen and // start_offset must not exceed the maximum size in bytes // of the EEPROM // Argument : unsigned char *buffer : Where to get the bytes to write // to the EEPROM. // Argument : unsigned short buflen : The size in bytes of buffer. // The sum of buflen and start_offset must not exceed the // maximum size in bytes of the EEPROM. // int gef_eeprom_write(int fd, unsigned char start_offset, unsigned char *buffer, unsigned short buflen) { int offset, index; int status; for (index=0, offset=start_offset; index<buflen && offset<EEPROM_SIZE; index++, offset++) { status = i2c_smbus_write_byte_data(fd, offset, buffer[index]); if (status < 0) { printf("ERROR: i2c_smbus_write_byte_data(fd, 0x%02X, 0x%02X) failed\n", offset, buffer[index]); printf("errno = %d, %s\n", errno, strerror(errno)); return -1; } /* Delay while the byte write completes */ gef_msec_delay(10); } return 0; } ////////////////////////////////////////////////////////////////////////////// // // Function name : gef_msec_delay // // Description : Delay for a number of milliseconds before returning // // Return type : void // // Argument : unsigned int msecs : The number of milliseconds to delay // void gef_msec_delay(unsigned int msecs) { struct timeval s_current, s_start; struct timezone tz; unsigned int current, start; /* Get initial time */ gettimeofday(&s_start, &tz); start = s_start.tv_sec*1000000 + s_start.tv_usec; /* Loop until msecs time have elapsed */ do { gettimeofday(&s_current, &tz); current = s_current.tv_sec*1000000 + s_current.tv_usec; } while ((current-start) < (msecs*1000)); } ------------- ________________________________ From: linuxppc-dev-bounces+tmarri=amcc....@ozlabs.org on behalf of Henry Bausley Sent: Tue 3/31/2009 5:41 PM To: linuxppc-dev@ozlabs.org Subject: PowerPC 460EX AD7416 Temperature Sensor Does anyone know if the I2C temperature sensor is functioning on the AMCC 460EX? When I do a cat /proc/ad7416 I get the following crash. Unable to handle kernel paging request for data at address 0x00000000 Faulting instruction address: 0xc02cbe28 Oops: Kernel access of bad area, sig: 11 [#1] PowerPC 44x Platform NIP: c02cbe28 LR: c023cec8 CTR: c023d314 REGS: ef107d90 TRAP: 0300 Not tainted (2.6.28.7) MSR: 00029000 <EE,ME> CR: 88000444 XER: 00000000 DEAR: 00000000, ESR: 00000000 TASK = ef8590c0[2611] 'cat' THREAD: ef106000 GPR00: 00000000 ef107e40 ef8590c0 00000000 ef107e9c 00000000 00000c00 ef107e98 GPR08: 00000000 c0330000 ffffffff c0330000 48000448 1001cb7c 100042bc 100df49c GPR16: 00000002 00000400 c032f014 c032efe4 ef107e9c ef107e98 bfffffff efb43a00 GPR24: ef61d000 00000000 ef107f20 ef107e98 00000c00 c0400000 00001000 efb43a00 NIP [c02cbe28] mutex_lock+0x0/0x1c LR [c023cec8] ad7416_read_temp+0x24/0x80 Call Trace: [ef107e40] [00000400] 0x400 (unreliable) [ef107e70] [c023d334] i2c_ad7416_read_proc+0x20/0x70 [ef107e90] [c00e8018] proc_file_read+0x108/0x334 [ef107ee0] [c00e2d3c] proc_reg_read+0x4c/0x70 [ef107ef0] [c00a54e8] vfs_read+0xb4/0x16c [ef107f10] [c00a58e0] sys_read+0x4c/0x90 [ef107f40] [c000ea88] ret_from_syscall+0x0/0x3c Instruction dump: 90010014 38000001 90030000 85230004 7f891800 419e000c 80690008 4bd50779 80010014 38210010 7c0803a6 4e800020 <7c001828> 3000ffff 7c00192d 40a2fff4 ---[ end trace 774db769c3754abe ]--- ********************************************************** Outbound scan for Spam or Virus by Barracuda at Delta Tau ********************************************************** _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
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