Commit a4bdfff7 authored by Sebastien Jan's avatar Sebastien Jan Committed by David S. Miller
Browse files

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: default avatarSebastien Jan <s-jan@ti.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 7d997466

drivers/net/ks8851.c

+228 −0
Original line number Diff line number Diff line
@@ -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,

drivers/net/ks8851.h

+13 −1
Original line number Diff line number Diff line
@@ -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)