ks8851: Low level functions for read/write to companion eeprom

Low-level functions provide 16bits words read and write capability
to ks8851 companion eeprom.

Signed-off-by: Sebastien Jan <s-jan@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Sebastien Jan 2010-05-05 08:45:53 +00:00 committed by David S. Miller
parent 7d9974666e
commit a4bdfff744
2 changed files with 241 additions and 1 deletions

View file

@ -1034,6 +1034,234 @@ static const struct net_device_ops ks8851_netdev_ops = {
.ndo_validate_addr = eth_validate_addr,
};
/* Companion eeprom access */
enum { /* EEPROM programming states */
EEPROM_CONTROL,
EEPROM_ADDRESS,
EEPROM_DATA,
EEPROM_COMPLETE
};
/**
* ks8851_eeprom_read - read a 16bits word in ks8851 companion EEPROM
* @dev: The network device the PHY is on.
* @addr: EEPROM address to read
*
* eeprom_size: used to define the data coding length. Can be changed
* through debug-fs.
*
* Programs a read on the EEPROM using ks8851 EEPROM SW access feature.
* Warning: The READ feature is not supported on ks8851 revision 0.
*
* Rough programming model:
* - on period start: set clock high and read value on bus
* - on period / 2: set clock low and program value on bus
* - start on period / 2
*/
unsigned int ks8851_eeprom_read(struct net_device *dev, unsigned int addr)
{
struct ks8851_net *ks = netdev_priv(dev);
int eepcr;
int ctrl = EEPROM_OP_READ;
int state = EEPROM_CONTROL;
int bit_count = EEPROM_OP_LEN - 1;
unsigned int data = 0;
int dummy;
unsigned int addr_len;
addr_len = (ks->eeprom_size == 128) ? 6 : 8;
/* start transaction: chip select high, authorize write */
mutex_lock(&ks->lock);
eepcr = EEPCR_EESA | EEPCR_EESRWA;
ks8851_wrreg16(ks, KS_EEPCR, eepcr);
eepcr |= EEPCR_EECS;
ks8851_wrreg16(ks, KS_EEPCR, eepcr);
mutex_unlock(&ks->lock);
while (state != EEPROM_COMPLETE) {
/* falling clock period starts... */
/* set EED_IO pin for control and address */
eepcr &= ~EEPCR_EEDO;
switch (state) {
case EEPROM_CONTROL:
eepcr |= ((ctrl >> bit_count) & 1) << 2;
if (bit_count-- <= 0) {
bit_count = addr_len - 1;
state = EEPROM_ADDRESS;
}
break;
case EEPROM_ADDRESS:
eepcr |= ((addr >> bit_count) & 1) << 2;
bit_count--;
break;
case EEPROM_DATA:
/* Change to receive mode */
eepcr &= ~EEPCR_EESRWA;
break;
}
/* lower clock */
eepcr &= ~EEPCR_EESCK;
mutex_lock(&ks->lock);
ks8851_wrreg16(ks, KS_EEPCR, eepcr);
mutex_unlock(&ks->lock);
/* waitread period / 2 */
udelay(EEPROM_SK_PERIOD / 2);
/* rising clock period starts... */
/* raise clock */
mutex_lock(&ks->lock);
eepcr |= EEPCR_EESCK;
ks8851_wrreg16(ks, KS_EEPCR, eepcr);
mutex_unlock(&ks->lock);
/* Manage read */
switch (state) {
case EEPROM_ADDRESS:
if (bit_count < 0) {
bit_count = EEPROM_DATA_LEN - 1;
state = EEPROM_DATA;
}
break;
case EEPROM_DATA:
mutex_lock(&ks->lock);
dummy = ks8851_rdreg16(ks, KS_EEPCR);
mutex_unlock(&ks->lock);
data |= ((dummy >> EEPCR_EESB_OFFSET) & 1) << bit_count;
if (bit_count-- <= 0)
state = EEPROM_COMPLETE;
break;
}
/* wait period / 2 */
udelay(EEPROM_SK_PERIOD / 2);
}
/* close transaction */
mutex_lock(&ks->lock);
eepcr &= ~EEPCR_EECS;
ks8851_wrreg16(ks, KS_EEPCR, eepcr);
eepcr = 0;
ks8851_wrreg16(ks, KS_EEPCR, eepcr);
mutex_unlock(&ks->lock);
return data;
}
/**
* ks8851_eeprom_write - write a 16bits word in ks8851 companion EEPROM
* @dev: The network device the PHY is on.
* @op: operand (can be WRITE, EWEN, EWDS)
* @addr: EEPROM address to write
* @data: data to write
*
* eeprom_size: used to define the data coding length. Can be changed
* through debug-fs.
*
* Programs a write on the EEPROM using ks8851 EEPROM SW access feature.
*
* Note that a write enable is required before writing data.
*
* Rough programming model:
* - on period start: set clock high
* - on period / 2: set clock low and program value on bus
* - start on period / 2
*/
void ks8851_eeprom_write(struct net_device *dev, unsigned int op,
unsigned int addr, unsigned int data)
{
struct ks8851_net *ks = netdev_priv(dev);
int eepcr;
int state = EEPROM_CONTROL;
int bit_count = EEPROM_OP_LEN - 1;
unsigned int addr_len;
addr_len = (ks->eeprom_size == 128) ? 6 : 8;
switch (op) {
case EEPROM_OP_EWEN:
addr = 0x30;
break;
case EEPROM_OP_EWDS:
addr = 0;
break;
}
/* start transaction: chip select high, authorize write */
mutex_lock(&ks->lock);
eepcr = EEPCR_EESA | EEPCR_EESRWA;
ks8851_wrreg16(ks, KS_EEPCR, eepcr);
eepcr |= EEPCR_EECS;
ks8851_wrreg16(ks, KS_EEPCR, eepcr);
mutex_unlock(&ks->lock);
while (state != EEPROM_COMPLETE) {
/* falling clock period starts... */
/* set EED_IO pin for control and address */
eepcr &= ~EEPCR_EEDO;
switch (state) {
case EEPROM_CONTROL:
eepcr |= ((op >> bit_count) & 1) << 2;
if (bit_count-- <= 0) {
bit_count = addr_len - 1;
state = EEPROM_ADDRESS;
}
break;
case EEPROM_ADDRESS:
eepcr |= ((addr >> bit_count) & 1) << 2;
if (bit_count-- <= 0) {
if (op == EEPROM_OP_WRITE) {
bit_count = EEPROM_DATA_LEN - 1;
state = EEPROM_DATA;
} else {
state = EEPROM_COMPLETE;
}
}
break;
case EEPROM_DATA:
eepcr |= ((data >> bit_count) & 1) << 2;
if (bit_count-- <= 0)
state = EEPROM_COMPLETE;
break;
}
/* lower clock */
eepcr &= ~EEPCR_EESCK;
mutex_lock(&ks->lock);
ks8851_wrreg16(ks, KS_EEPCR, eepcr);
mutex_unlock(&ks->lock);
/* wait period / 2 */
udelay(EEPROM_SK_PERIOD / 2);
/* rising clock period starts... */
/* raise clock */
eepcr |= EEPCR_EESCK;
mutex_lock(&ks->lock);
ks8851_wrreg16(ks, KS_EEPCR, eepcr);
mutex_unlock(&ks->lock);
/* wait period / 2 */
udelay(EEPROM_SK_PERIOD / 2);
}
/* close transaction */
mutex_lock(&ks->lock);
eepcr &= ~EEPCR_EECS;
ks8851_wrreg16(ks, KS_EEPCR, eepcr);
eepcr = 0;
ks8851_wrreg16(ks, KS_EEPCR, eepcr);
mutex_unlock(&ks->lock);
}
/* ethtool support */
static void ks8851_get_drvinfo(struct net_device *dev,

View file

@ -25,12 +25,24 @@
#define OBCR_ODS_16mA (1 << 6)
#define KS_EEPCR 0x22
#define EEPCR_EESRWA (1 << 5)
#define EEPCR_EESA (1 << 4)
#define EEPCR_EESB (1 << 3)
#define EEPCR_EESB_OFFSET 3
#define EEPCR_EESB (1 << EEPCR_EESB_OFFSET)
#define EEPCR_EEDO (1 << 2)
#define EEPCR_EESCK (1 << 1)
#define EEPCR_EECS (1 << 0)
#define EEPROM_OP_LEN 3 /* bits:*/
#define EEPROM_OP_READ 0x06
#define EEPROM_OP_EWEN 0x04
#define EEPROM_OP_WRITE 0x05
#define EEPROM_OP_EWDS 0x14
#define EEPROM_DATA_LEN 16 /* 16 bits EEPROM */
#define EEPROM_WRITE_TIME 4 /* wrt ack time in ms */
#define EEPROM_SK_PERIOD 400 /* in us */
#define KS_MBIR 0x24
#define MBIR_TXMBF (1 << 12)
#define MBIR_TXMBFA (1 << 11)