u-boot/arch/powerpc/cpu/mpc8220/dramSetup.c
Stefan Roese a47a12becf Move arch/ppc to arch/powerpc
As discussed on the list, move "arch/ppc" to "arch/powerpc" to
better match the Linux directory structure.

Please note that this patch also changes the "ppc" target in
MAKEALL to "powerpc" to match this new infrastructure. But "ppc"
is kept as an alias for now, to not break compatibility with
scripts using this name.

Signed-off-by: Stefan Roese <sr@denx.de>
Acked-by: Wolfgang Denk <wd@denx.de>
Acked-by: Detlev Zundel <dzu@denx.de>
Acked-by: Kim Phillips <kim.phillips@freescale.com>
Cc: Peter Tyser <ptyser@xes-inc.com>
Cc: Anatolij Gustschin <agust@denx.de>
2010-04-21 23:42:38 +02:00

752 lines
20 KiB
C

/*
* (C) Copyright 2004, Freescale, Inc
* TsiChung Liew, Tsi-Chung.Liew@freescale.com
*
* 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
*/
/*
DESCRIPTION
Read Dram spd and base on its information to calculate the memory size,
characteristics to initialize the dram on MPC8220
*/
#include <common.h>
#include <mpc8220.h>
#include "i2cCore.h"
#include "dramSetup.h"
DECLARE_GLOBAL_DATA_PTR;
#define SPD_SIZE CONFIG_SYS_SDRAM_SPD_SIZE
#define DRAM_SPD (CONFIG_SYS_SDRAM_SPD_I2C_ADDR)<<1 /* on Board SPD eeprom */
#define TOTAL_BANK CONFIG_SYS_SDRAM_TOTAL_BANKS
int spd_status (volatile i2c8220_t * pi2c, u8 sta_bit, u8 truefalse)
{
int i;
for (i = 0; i < I2C_POLL_COUNT; i++) {
if ((pi2c->sr & sta_bit) == (truefalse ? sta_bit : 0))
return (OK);
}
return (ERROR);
}
int spd_clear (volatile i2c8220_t * pi2c)
{
pi2c->adr = 0;
pi2c->fdr = 0;
pi2c->cr = 0;
pi2c->sr = 0;
return (OK);
}
int spd_stop (volatile i2c8220_t * pi2c)
{
pi2c->cr &= ~I2C_CTL_STA; /* Generate stop signal */
if (spd_status (pi2c, I2C_STA_BB, 0) != OK)
return ERROR;
return (OK);
}
int spd_readbyte (volatile i2c8220_t * pi2c, u8 * readb, int *index)
{
pi2c->sr &= ~I2C_STA_IF; /* Clear Interrupt Bit */
*readb = pi2c->dr; /* Read a byte */
/*
Set I2C_CTRL_TXAK will cause Transfer pending and
set I2C_CTRL_STA will cause Interrupt pending
*/
if (*index != 2) {
if (spd_status (pi2c, I2C_STA_CF, 1) != OK) /* Transfer not complete? */
return ERROR;
}
if (*index != 1) {
if (spd_status (pi2c, I2C_STA_IF, 1) != OK)
return ERROR;
}
return (OK);
}
int readSpdData (u8 * spdData)
{
volatile i2c8220_t *pi2cReg;
volatile pcfg8220_t *pcfg;
u8 slvAdr = DRAM_SPD;
u8 Tmp;
int Length = SPD_SIZE;
int i = 0;
/* Enable Port Configuration for SDA and SDL signals */
pcfg = (volatile pcfg8220_t *) (MMAP_PCFG);
__asm__ ("sync");
pcfg->pcfg3 &= ~CONFIG_SYS_I2C_PORT3_CONFIG;
__asm__ ("sync");
/* Points the structure to I2c mbar memory offset */
pi2cReg = (volatile i2c8220_t *) (MMAP_I2C);
/* Clear FDR, ADR, SR and CR reg */
pi2cReg->adr = 0;
pi2cReg->fdr = 0;
pi2cReg->cr = 0;
pi2cReg->sr = 0;
/* Set for fix XLB Bus Frequency */
switch (gd->bus_clk) {
case 60000000:
pi2cReg->fdr = 0x15;
break;
case 70000000:
pi2cReg->fdr = 0x16;
break;
case 80000000:
pi2cReg->fdr = 0x3a;
break;
case 90000000:
pi2cReg->fdr = 0x17;
break;
case 100000000:
pi2cReg->fdr = 0x3b;
break;
case 110000000:
pi2cReg->fdr = 0x18;
break;
case 120000000:
pi2cReg->fdr = 0x19;
break;
case 130000000:
pi2cReg->fdr = 0x1a;
break;
}
pi2cReg->adr = CONFIG_SYS_I2C_SLAVE<<1;
pi2cReg->cr = I2C_CTL_EN; /* Set Enable */
/*
The I2C bus should be in Idle state. If the bus is busy,
clear the STA bit in control register
*/
if (spd_status (pi2cReg, I2C_STA_BB, 0) != OK) {
if ((pi2cReg->cr & I2C_CTL_STA) == I2C_CTL_STA)
pi2cReg->cr &= ~I2C_CTL_STA;
/* Check again if it is still busy, return error if found */
if (spd_status (pi2cReg, I2C_STA_BB, 1) == OK)
return ERROR;
}
pi2cReg->cr |= I2C_CTL_TX; /* Enable the I2c for TX, Ack */
pi2cReg->cr |= I2C_CTL_STA; /* Generate start signal */
if (spd_status (pi2cReg, I2C_STA_BB, 1) != OK)
return ERROR;
/* Write slave address */
pi2cReg->sr &= ~I2C_STA_IF; /* Clear Interrupt */
pi2cReg->dr = slvAdr; /* Write a byte */
if (spd_status (pi2cReg, I2C_STA_CF, 1) != OK) { /* Transfer not complete? */
spd_stop (pi2cReg);
return ERROR;
}
if (spd_status (pi2cReg, I2C_STA_IF, 1) != OK) {
spd_stop (pi2cReg);
return ERROR;
}
/* Issue the offset to start */
pi2cReg->sr &= ~I2C_STA_IF; /* Clear Interrupt */
pi2cReg->dr = 0; /* Write a byte */
if (spd_status (pi2cReg, I2C_STA_CF, 1) != OK) { /* Transfer not complete? */
spd_stop (pi2cReg);
return ERROR;
}
if (spd_status (pi2cReg, I2C_STA_IF, 1) != OK) {
spd_stop (pi2cReg);
return ERROR;
}
/* Set repeat start */
pi2cReg->cr |= I2C_CTL_RSTA; /* Repeat Start */
pi2cReg->sr &= ~I2C_STA_IF; /* Clear Interrupt */
pi2cReg->dr = slvAdr | 1; /* Write a byte */
if (spd_status (pi2cReg, I2C_STA_CF, 1) != OK) { /* Transfer not complete? */
spd_stop (pi2cReg);
return ERROR;
}
if (spd_status (pi2cReg, I2C_STA_IF, 1) != OK) {
spd_stop (pi2cReg);
return ERROR;
}
if (((pi2cReg->sr & 0x07) == 0x07) || (pi2cReg->sr & 0x01))
return ERROR;
pi2cReg->cr &= ~I2C_CTL_TX; /* Set receive mode */
if (((pi2cReg->sr & 0x07) == 0x07) || (pi2cReg->sr & 0x01))
return ERROR;
/* Dummy Read */
if (spd_readbyte (pi2cReg, &Tmp, &i) != OK) {
spd_stop (pi2cReg);
return ERROR;
}
i = 0;
while (Length) {
if (Length == 2)
pi2cReg->cr |= I2C_CTL_TXAK;
if (Length == 1)
pi2cReg->cr &= ~I2C_CTL_STA;
if (spd_readbyte (pi2cReg, spdData, &Length) != OK) {
return spd_stop (pi2cReg);
}
i++;
Length--;
spdData++;
}
/* Stop the service */
spd_stop (pi2cReg);
return OK;
}
int getBankInfo (int bank, draminfo_t * pBank)
{
int status;
int checksum;
int count;
u8 spdData[SPD_SIZE];
if (bank > 2 || pBank == 0) {
/* illegal values */
return (-42);
}
status = readSpdData (&spdData[0]);
if (status < 0)
return (-1);
/* check the checksum */
for (count = 0, checksum = 0; count < LOC_CHECKSUM; count++)
checksum += spdData[count];
checksum = checksum - ((checksum / 256) * 256);
if (checksum != spdData[LOC_CHECKSUM])
return (-2);
/* Get the memory type */
if (!
((spdData[LOC_TYPE] == TYPE_DDR)
|| (spdData[LOC_TYPE] == TYPE_SDR)))
/* not one of the types we support */
return (-3);
pBank->type = spdData[LOC_TYPE];
/* Set logical banks */
pBank->banks = spdData[LOC_LOGICAL_BANKS];
/* Check that we have enough physical banks to cover the bank we are
* figuring out. Odd-numbered banks correspond to the second bank
* on the device.
*/
if (bank & 1) {
/* Second bank of a "device" */
if (spdData[LOC_PHYS_BANKS] < 2)
/* this bank doesn't exist on the "device" */
return (-4);
if (spdData[LOC_ROWS] & 0xf0)
/* Two asymmetric banks */
pBank->rows = spdData[LOC_ROWS] >> 4;
else
pBank->rows = spdData[LOC_ROWS];
if (spdData[LOC_COLS] & 0xf0)
/* Two asymmetric banks */
pBank->cols = spdData[LOC_COLS] >> 4;
else
pBank->cols = spdData[LOC_COLS];
} else {
/* First bank of a "device" */
pBank->rows = spdData[LOC_ROWS];
pBank->cols = spdData[LOC_COLS];
}
pBank->width = spdData[LOC_WIDTH_HIGH] << 8 | spdData[LOC_WIDTH_LOW];
pBank->bursts = spdData[LOC_BURSTS];
pBank->CAS = spdData[LOC_CAS];
pBank->CS = spdData[LOC_CS];
pBank->WE = spdData[LOC_WE];
pBank->Trp = spdData[LOC_Trp];
pBank->Trcd = spdData[LOC_Trcd];
pBank->buffered = spdData[LOC_Buffered] & 1;
pBank->refresh = spdData[LOC_REFRESH];
return (0);
}
/* checkMuxSetting -- given a row/column device geometry, return a mask
* of the valid DRAM controller addr_mux settings for
* that geometry.
*
* Arguments: u8 rows: number of row addresses in this device
* u8 columns: number of column addresses in this device
*
* Returns: a mask of the allowed addr_mux settings for this
* geometry. Each bit in the mask represents a
* possible addr_mux settings (for example, the
* (1<<2) bit in the mask represents the 0b10 setting)/
*
*/
u8 checkMuxSetting (u8 rows, u8 columns)
{
muxdesc_t *pIdx, *pMux;
u8 mask;
int lrows, lcolumns;
u32 mux[4] = { 0x00080c04, 0x01080d03, 0x02080e02, 0xffffffff };
/* Setup MuxDescriptor in SRAM space */
/* MUXDESC AddressRuns [] = {
{ 0, 8, 12, 4 }, / setting, columns, rows, extra columns /
{ 1, 8, 13, 3 }, / setting, columns, rows, extra columns /
{ 2, 8, 14, 2 }, / setting, columns, rows, extra columns /
{ 0xff } / list terminator /
}; */
pIdx = (muxdesc_t *) & mux[0];
/* Check rows x columns against each possible address mux setting */
for (pMux = pIdx, mask = 0;; pMux++) {
lrows = rows;
lcolumns = columns;
if (pMux->MuxValue == 0xff)
break; /* end of list */
/* For a given mux setting, since we want all the memory in a
* device to be contiguous, we want the device "use up" the
* address lines such that there are no extra column or row
* address lines on the device.
*/
lcolumns -= pMux->Columns;
if (lcolumns < 0)
/* Not enough columns to get to the rows */
continue;
lrows -= pMux->Rows;
if (lrows > 0)
/* we have extra rows left -- can't do that! */
continue;
/* At this point, we either have to have used up all the
* rows or we have to have no columns left.
*/
if (lcolumns != 0 && lrows != 0)
/* rows AND columns are left. Bad! */
continue;
lcolumns -= pMux->MoreColumns;
if (lcolumns <= 0)
mask |= (1 << pMux->MuxValue);
}
return (mask);
}
u32 dramSetup (void)
{
draminfo_t DramInfo[TOTAL_BANK];
draminfo_t *pDramInfo;
u32 size, temp, cfg_value, mode_value, refresh;
u8 *ptr;
u8 bursts, Trp, Trcd, type, buffered;
u8 muxmask, rows, columns;
int count, banknum;
u32 *prefresh, *pIdx;
u32 refrate[8] = { 15625, 3900, 7800, 31300,
62500, 125000, 0xffffffff, 0xffffffff
};
volatile sysconf8220_t *sysconf;
volatile memctl8220_t *memctl;
sysconf = (volatile sysconf8220_t *) MMAP_MBAR;
memctl = (volatile memctl8220_t *) MMAP_MEMCTL;
/* Set everything in the descriptions to zero */
ptr = (u8 *) & DramInfo[0];
for (count = 0; count < sizeof (DramInfo); count++)
*ptr++ = 0;
for (banknum = 0; banknum < TOTAL_BANK; banknum++)
sysconf->cscfg[banknum];
/* Descriptions of row/column address muxing for various
* addr_mux settings.
*/
pIdx = prefresh = (u32 *) & refrate[0];
/* Get all the info for all three logical banks */
bursts = 0xff;
Trp = 0;
Trcd = 0;
type = 0;
buffered = 0xff;
refresh = 0xffffffff;
muxmask = 0xff;
/* Two bank, CS0 and CS1 */
for (banknum = 0, pDramInfo = &DramInfo[0];
banknum < TOTAL_BANK; banknum++, pDramInfo++) {
pDramInfo->ordinal = banknum; /* initial sorting */
if (getBankInfo (banknum, pDramInfo) < 0)
continue;
/* get cumulative parameters of all three banks */
if (type && pDramInfo->type != type)
return 0;
type = pDramInfo->type;
rows = pDramInfo->rows;
columns = pDramInfo->cols;
/* This chip only supports 13 DRAM memory lines, but some devices
* have 14 rows. To deal with this, ignore the 14th address line
* by limiting the number of rows (and columns) to 13. This will
* mean that for 14-row devices we will only be able to use
* half of the memory, but it's better than nothing.
*/
if (rows > 13)
rows = 13;
if (columns > 13)
columns = 13;
pDramInfo->size =
((1 << (rows + columns)) * pDramInfo->width);
pDramInfo->size *= pDramInfo->banks;
pDramInfo->size >>= 3;
/* figure out which addr_mux configurations will support this device */
muxmask &= checkMuxSetting (rows, columns);
if (muxmask == 0)
return 0;
buffered = pDramInfo->buffered;
bursts &= pDramInfo->bursts; /* union of all bursts */
if (pDramInfo->Trp > Trp) /* worst case (longest) Trp */
Trp = pDramInfo->Trp;
if (pDramInfo->Trcd > Trcd) /* worst case (longest) Trcd */
Trcd = pDramInfo->Trcd;
prefresh = pIdx;
/* worst case (shortest) Refresh period */
if (refresh > prefresh[pDramInfo->refresh & 7])
refresh = prefresh[pDramInfo->refresh & 7];
} /* for loop */
/* We only allow a burst length of 8! */
if (!(bursts & 8))
bursts = 8;
/* Sort the devices. In order to get each chip select region
* aligned properly, put the biggest device at the lowest address.
* A simple bubble sort will do the trick.
*/
for (banknum = 0, pDramInfo = &DramInfo[0];
banknum < TOTAL_BANK; banknum++, pDramInfo++) {
int i;
for (i = 0; i < TOTAL_BANK; i++) {
if (pDramInfo->size < DramInfo[i].size &&
pDramInfo->ordinal < DramInfo[i].ordinal) {
/* If the current bank is smaller, but if the ordinal is also
* smaller, swap the ordinals
*/
u8 temp8;
temp8 = DramInfo[i].ordinal;
DramInfo[i].ordinal = pDramInfo->ordinal;
pDramInfo->ordinal = temp8;
}
}
}
/* Now figure out the base address for each bank. While
* we're at it, figure out how much memory there is.
*
*/
size = 0;
for (banknum = 0; banknum < TOTAL_BANK; banknum++) {
int i;
for (i = 0; i < TOTAL_BANK; i++) {
if (DramInfo[i].ordinal == banknum
&& DramInfo[i].size != 0) {
DramInfo[i].base = size;
size += DramInfo[i].size;
}
}
}
/* Set up the Drive Strength register */
sysconf->sdramds = CONFIG_SYS_SDRAM_DRIVE_STRENGTH;
/* ********************** Cfg 1 ************************* */
/* Set the single read to read/write/precharge delay */
cfg_value = CFG1_SRD2RWP ((type == TYPE_DDR) ? 7 : 0xb);
/* Set the single write to read/write/precharge delay.
* This may or may not be correct. The controller spec
* says "tWR", but "tWR" does not appear in the SPD. It
* always seems to be 15nsec for the class of device we're
* using, which turns out to be 2 clock cycles at 133MHz,
* so that's what we're going to use.
*
* HOWEVER, because of a bug in the controller, for DDR
* we need to set this to be the same as the value
* calculated for bwt2rwp.
*/
cfg_value |= CFG1_SWT2RWP ((type == TYPE_DDR) ? 7 : 2);
/* Set the Read CAS latency. We're going to use a CL of
* 2.5 for DDR and 2 SDR.
*/
cfg_value |= CFG1_RLATENCY ((type == TYPE_DDR) ? 7 : 2);
/* Set the Active to Read/Write delay. This depends
* on Trcd which is reported as nanoseconds times 4.
* We want to calculate Trcd (in nanoseconds) times XLB clock (in Hz)
* which gives us a dimensionless quantity. Play games with
* the divisions so we don't run out of dynamic ranges.
*/
/* account for megaherz and the times 4 */
temp = (Trcd * (gd->bus_clk / 1000000)) / 4;
/* account for nanoseconds and round up, with a minimum value of 2 */
temp = ((temp + 999) / 1000) - 1;
if (temp < 2)
temp = 2;
cfg_value |= CFG1_ACT2WR (temp);
/* Set the precharge to active delay. This depends
* on Trp which is reported as nanoseconds times 4.
* We want to calculate Trp (in nanoseconds) times XLB clock (in Hz)
* which gives us a dimensionless quantity. Play games with
* the divisions so we don't run out of dynamic ranges.
*/
/* account for megaherz and the times 4 */
temp = (Trp * (gd->bus_clk / 1000000)) / 4;
/* account for nanoseconds and round up, then subtract 1, with a
* minumum value of 1 and a maximum value of 7.
*/
temp = (((temp + 999) / 1000) - 1) & 7;
if (temp < 1)
temp = 1;
cfg_value |= CFG1_PRE2ACT (temp);
/* Set refresh to active delay. This depends
* on Trfc which is not reported in the SPD.
* We'll use a nominal value of 75nsec which is
* what the controller spec uses.
*/
temp = (75 * (gd->bus_clk / 1000000));
/* account for nanoseconds and round up, then subtract 1 */
cfg_value |= CFG1_REF2ACT (((temp + 999) / 1000) - 1);
/* Set the write latency, using the values given in the controller spec */
cfg_value |= CFG1_WLATENCY ((type == TYPE_DDR) ? 3 : 0);
memctl->cfg1 = cfg_value; /* cfg 1 */
asm volatile ("sync");
/* ********************** Cfg 2 ************************* */
/* Set the burst read to read/precharge delay */
cfg_value = CFG2_BRD2RP ((type == TYPE_DDR) ? 5 : 8);
/* Set the burst write to read/precharge delay. Semi-magic numbers
* based on the controller spec recommendations, assuming tWR is
* two clock cycles.
*/
cfg_value |= CFG2_BWT2RWP ((type == TYPE_DDR) ? 7 : 10);
/* Set the Burst read to write delay. Semi-magic numbers
* based on the DRAM controller documentation.
*/
cfg_value |= CFG2_BRD2WT ((type == TYPE_DDR) ? 7 : 0xb);
/* Set the burst length -- must be 8!! Well, 7, actually, becuase
* it's burst lenght minus 1.
*/
cfg_value |= CFG2_BURSTLEN (7);
memctl->cfg2 = cfg_value; /* cfg 2 */
asm volatile ("sync");
/* ********************** mode ************************* */
/* Set enable bit, CKE high/low bits, and the DDR/SDR mode bit,
* disable automatic refresh.
*/
cfg_value = CTL_MODE_ENABLE | CTL_CKE_HIGH |
((type == TYPE_DDR) ? CTL_DDR_MODE : 0);
/* Set the address mux based on whichever setting(s) is/are common
* to all the devices we have. If there is more than one, choose
* one arbitrarily.
*/
if (muxmask & 0x4)
cfg_value |= CTL_ADDRMUX (2);
else if (muxmask & 0x2)
cfg_value |= CTL_ADDRMUX (1);
else
cfg_value |= CTL_ADDRMUX (0);
/* Set the refresh interval. */
temp = ((refresh * (gd->bus_clk / 1000000)) / (1000 * 64)) - 1;
cfg_value |= CTL_REFRESH_INTERVAL (temp);
/* Set buffered/non-buffered memory */
if (buffered)
cfg_value |= CTL_BUFFERED;
memctl->ctrl = cfg_value; /* ctrl */
asm volatile ("sync");
if (type == TYPE_DDR) {
/* issue precharge all */
temp = cfg_value | CTL_PRECHARGE_CMD;
memctl->ctrl = temp; /* ctrl */
asm volatile ("sync");
}
/* Set up mode value for CAS latency */
#if (CONFIG_SYS_SDRAM_CAS_LATENCY==5) /* CL=2.5 */
mode_value = (MODE_MODE | MODE_BURSTLEN (MODE_BURSTLEN_8) |
MODE_BT_SEQUENTIAL | MODE_CL (MODE_CL_2p5) | MODE_CMD);
#else
mode_value = (MODE_MODE | MODE_BURSTLEN (MODE_BURSTLEN_8) |
MODE_BT_SEQUENTIAL | MODE_CL (MODE_CL_2) | MODE_CMD);
#endif
asm volatile ("sync");
/* Write Extended Mode - enable DLL */
if (type == TYPE_DDR) {
temp = MODE_EXTENDED | MODE_X_DLL_ENABLE |
MODE_X_DS_NORMAL | MODE_CMD;
memctl->mode = (temp >> 16); /* mode */
asm volatile ("sync");
/* Write Mode - reset DLL, set CAS latency */
temp = mode_value | MODE_OPMODE (MODE_OPMODE_RESETDLL);
memctl->mode = (temp >> 16); /* mode */
asm volatile ("sync");
}
/* Program the chip selects. */
for (banknum = 0; banknum < TOTAL_BANK; banknum++) {
if (DramInfo[banknum].size != 0) {
u32 mask;
int i;
for (i = 0, mask = 1; i < 32; mask <<= 1, i++) {
if (DramInfo[banknum].size & mask)
break;
}
temp = (DramInfo[banknum].base & 0xfff00000) | (i -
1);
sysconf->cscfg[banknum] = temp;
asm volatile ("sync");
}
}
/* Wait for DLL lock */
udelay (200);
temp = cfg_value | CTL_PRECHARGE_CMD; /* issue precharge all */
memctl->ctrl = temp; /* ctrl */
asm volatile ("sync");
temp = cfg_value | CTL_REFRESH_CMD; /* issue precharge all */
memctl->ctrl = temp; /* ctrl */
asm volatile ("sync");
memctl->ctrl = temp; /* ctrl */
asm volatile ("sync");
/* Write Mode - DLL normal */
temp = mode_value | MODE_OPMODE (MODE_OPMODE_NORMAL);
memctl->mode = (temp >> 16); /* mode */
asm volatile ("sync");
/* Enable refresh, enable DQS's (if DDR), and lock the control register */
cfg_value &= ~CTL_MODE_ENABLE; /* lock register */
cfg_value |= CTL_REFRESH_ENABLE; /* enable refresh */
if (type == TYPE_DDR)
cfg_value |= CTL_DQSOEN (0xf); /* enable DQS's for DDR */
memctl->ctrl = cfg_value; /* ctrl */
asm volatile ("sync");
return size;
}