This is how to read/write CPLD registers on DM6467T

add to bottom of board-dm6467t-evm.c said:

 

/*-----------------------------------------------------------------------------

Extensions for device driver for reading/writing CPLD registers

-------------------------------------------------------------------------------*/

// USAGE:

//

// From application code:

// int fd;

// if (0 > (fd = open("/dev/cpldregs", O_RDWR))) {

// perror("open /dev/cpldregs");

// exit(EXIT_FAILURE);

// }

// ioctl(fd, args...);

// close(fd);

//

#define DRIVERNAME "cpldregs"

#define cpldregs_MAX_SIZE (2)

static dev_t cpldregs_devno;

static struct class *cpldregs_class;

struct device *pdev;

struct cdev cpldregs_cdev;

static int cpldregs_open(struct inode *inode, struct file *fp)

{

//printk(KERN_NOTICE "cpldregs_open()\n");

// Nothing to do, claim success

return(0);

}

static int cpldregs_release(struct inode *inode, struct file *fp)

{

//printk(KERN_NOTICE "cpldregs_release()\n");

// Nothing to do, claim success

return(0);

}

#include "myb/myb.h" // git/arch/arm/mach-davinci/include/myb/myb.h

static long cpldregs_ioctl(struct file *fd, unsigned int code, unsigned long arg)

{

long status = 0;

u8 data;

struct i2c_msg msg0[2] = { // For Reg0

{

.addr = cpld_reg0_client->addr,

.flags = I2C_M_RD,

.len = 1,

.buf = &data,

},

{

.addr = cpld_reg0_client->addr,

.flags = 0,

.len = 1,

.buf = &data,

},

};

struct i2c_msg msg1[2] = { // For Reg1

{

.addr = cpld_client->addr,

.flags = I2C_M_RD,

.len = 1,

.buf = &data,

},

{

.addr = cpld_client->addr,

.flags = 0,

.len = 1,

.buf = &data,

},

};

//printk(KERN_NOTICE "cpldregs_ioctl(,%d,%ld)\n",code,arg);

switch(code) {

case CPLDREGS_IOCTL_DISABLE_INTERNET_PHY: // Forces SYS_RESETn signal low, which disables Internet PHY chip, thus reducing current consumption

i2c_transfer(cpld_reg0_client->adapter, msg0, 1); // HgF doc: read existing value of Reg0

data |= MYB_SYS_RESET_IPHY; // HgF doc: in this case, set the bit which causes SYS_RESETn to go low

i2c_transfer(cpld_reg0_client->adapter, msg0 + 1, 1); // HgF doc: write revised value of Reg0

break;

case CPLDREGS_IOCTL_ENABLE_INTERNET_PHY: // Forces SYS_RESETn signal high, which enables Internet PHY chip, thus increasing current consumption

i2c_transfer(cpld_reg0_client->adapter, msg0, 1); // HgF doc: read existing value of Reg0

data &= ~MYB_SYS_RESET_IPHY; // HgF doc: in this case, clear the bit which causes SYS_RESETn to go high

i2c_transfer(cpld_reg0_client->adapter, msg0 + 1, 1); // HgF doc: write revised value of Reg0

break;

case CPLDREGS_IOCTL_DISABLE_VIDEO_IN: // Forces NTSC_PWD (TVP5147_PWD) signal high, which disable video input chip

i2c_transfer(cpld_client->adapter, msg1, 1); // HgF doc: read existing value of Reg0

data |= MYB_NTSC_PWD; // HgF doc: in this case, set the bit which causes NTSC_PWD (TVP5147_PWD) to go high

i2c_transfer(cpld_client->adapter, msg1 + 1, 1); // HgF doc: write revised value of Reg0

break;

case CPLDREGS_IOCTL_ENABLE_VIDEO_IN: // Forces NTSC_PWD (TVP5147_PWD) signal low, which enables video input chip

i2c_transfer(cpld_client->adapter, msg1, 1); // HgF doc: read existing value of Reg0

data &= ~MYB_NTSC_PWD; // HgF doc: in this case, clear the bit which causes NTSC_PWD (TVP5147_PWD) to go low

i2c_transfer(cpld_client->adapter, msg1 + 1, 1); // HgF doc: write revised value of Reg0

break;

case CPLDREGS_GET_REGS: // Return CPLD register values, concatenated into one long as Reg1:Reg0.  Can support up to Reg3:Reg2:Reg1:Reg0, where Reg0 is least significant byte

status = 0;

i2c_transfer(cpld_reg0_client->adapter, msg0, 1); // HgF doc: read existing value of Reg0

status |= (data & 0xFF); // HgF Add in this register byte

i2c_transfer(cpld_client->adapter, msg1, 1); // HgF doc: read existing value of Reg1

status |= ((data & 0xFF) << 8); // HgF Add in this register byte

break;

case CPLDREGS_SET_REGS: // Set CPLD register values, concatenated into one long as Reg1:Reg0.  Can support up to Reg3:Reg2:Reg1:Reg0, where Reg0 is least significant byte

// DANGEROUS!!!!!!!!!!!!!  BE SURE TO CPLDREGS_GET_REGS FIRST, MODIFY, THEN WRITE HERE

// DANGEROUS!!!!!!!!!!!!!  NOTE IN FUTURE, THERE MAY BE LIVE READ-ONLY (STATUS) BITS IN REGS, SO NEED TO NOT CHANGE THEM INAPPROPRIATELY. // (Perhaps code CPLD Regs as follows.  Mix live writable bits with mirrors of read-only bits, so if read-only bit gets written, mirroring will soon correct)

data = (arg & 0xFF); // HgF Isolate Reg0 from least significant byte position

i2c_transfer(cpld_reg0_client->adapter, msg0 + 1, 1); // HgF doc: write revised value of Reg0

data = ((arg>>8) & 0xFF); // HgF Isolate Reg1 from least significant byte position

i2c_transfer(cpld_client->adapter, msg1 + 1, 1); // HgF doc: write revised value of Reg1

break;

}

return(status);

}

struct file_operations cpldregs_fops = {

.owner = THIS_MODULE,

.open = cpldregs_open,

.unlocked_ioctl = cpldregs_ioctl,

.release = cpldregs_release,

}

MODULE_DESCRIPTION("CPLD Regs Driver");

static int __init cpldregs_module_init(void)

{

int status;

//printk(KERN_NOTICE /*KERN_NOTICE*/ "cpldregs_module_init called\n");

cpldregs_class = class_create(THIS_MODULE, DRIVERNAME);

if (IS_ERR(cpldregs_class)) {

status = PTR_ERR(cpldregs_class);

printk(KERN_ERR "unable to create cpldregs class %d\n", status);

return status;

}

status = alloc_chrdev_region(&cpldregs_devno, 0, 1, DRIVERNAME);

if (status) {

printk(KERN_ERR "alloc_chrdev_region %d\n", status);

class_destroy(cpldregs_class);

return status;

}

/* Setup the sysfs files for the printer gadget. HgF: Is it /sys/... or /dev/cpldregs that's created here? */

pdev = device_create(cpldregs_class, NULL, cpldregs_devno, NULL, DRIVERNAME);

if (IS_ERR(pdev)) {

printk(KERN_ERR "Failed to create device: %s\n", DRIVERNAME);

return status;

}

/*

* Register a character device as an interface to a user mode

* program that handles the printer specific functionality.

*/

cdev_init(&cpldregs_cdev, &cpldregs_fops); // cpldregs_fops registered here

cpldregs_cdev.owner = THIS_MODULE;

status = cdev_add(&cpldregs_cdev, cpldregs_devno, 1);

if (status) {

printk(KERN_ERR "Failed to open char device\n");

return status;

}

//printk(KERN_NOTICE /*KERN_NOTICE*/ "cpldregs_module_init SUCCESS\n");

return status;

}

module_init(cpldregs_module_init);

static void __exit cpldregs_cleanup(void)

{

/* Remove sysfs files */

device_destroy(cpldregs_class, cpldregs_devno);

/* Remove Character Device */

cdev_del(&cpldregs_cdev);

class_destroy(cpldregs_class);

unregister_chrdev_region(cpldregs_devno, 1);

}

module_exit(cpldregs_cleanup);