@ -30,39 +30,32 @@
# include "hsdramc1.h"
unsigned long sdram_init ( const struct sdram_info * info )
unsigned long sdram_init ( void * sdram_base , const struct sdram_config * config )
{
unsigned long * sdram = ( unsigned long * ) uncached ( info - > phys_addr ) ;
unsigned long sdram_size ;
unsigned long tmp ;
unsigned long bus_hz ;
uint32_t cfgreg ;
unsigned int i ;
if ( ! info - > refresh_period )
panic ( " ERROR: SDRAM refresh period == 0. "
" Please update the board code \n " ) ;
tmp = ( HSDRAMC1_BF ( NC , info - > col_bits - 8 )
| HSDRAMC1_BF ( NR , info - > row_bits - 11 )
| HSDRAMC1_BF ( NB , info - > bank_bits - 1 )
| HSDRAMC1_BF ( CAS , info - > cas )
| HSDRAMC1_BF ( TWR , info - > twr )
| HSDRAMC1_BF ( TRC , info - > trc )
| HSDRAMC1_BF ( TRP , info - > trp )
| HSDRAMC1_BF ( TRCD , info - > trcd )
| HSDRAMC1_BF ( TRAS , info - > tras )
| HSDRAMC1_BF ( TXSR , info - > txsr ) ) ;
# ifdef CFG_SDRAM_16BIT
tmp | = HSDRAMC1_BIT ( DBW ) ;
sdram_size = 1 < < ( info - > row_bits + info - > col_bits
+ info - > bank_bits + 1 ) ;
# else
sdram_size = 1 < < ( info - > row_bits + info - > col_bits
+ info - > bank_bits + 2 ) ;
# endif
hsdramc1_writel ( CR , tmp ) ;
cfgreg = ( HSDRAMC1_BF ( NC , config - > col_bits - 8 )
| HSDRAMC1_BF ( NR , config - > row_bits - 11 )
| HSDRAMC1_BF ( NB , config - > bank_bits - 1 )
| HSDRAMC1_BF ( CAS , config - > cas )
| HSDRAMC1_BF ( TWR , config - > twr )
| HSDRAMC1_BF ( TRC , config - > trc )
| HSDRAMC1_BF ( TRP , config - > trp )
| HSDRAMC1_BF ( TRCD , config - > trcd )
| HSDRAMC1_BF ( TRAS , config - > tras )
| HSDRAMC1_BF ( TXSR , config - > txsr ) ) ;
if ( config - > data_bits = = SDRAM_DATA_16BIT )
cfgreg | = HSDRAMC1_BIT ( DBW ) ;
hsdramc1_writel ( CR , cfgreg ) ;
/* Send a NOP to turn on the clock (necessary on some chips) */
hsdramc1_writel ( MR , HSDRAMC1_MODE_NOP ) ;
hsdramc1_readl ( MR ) ;
writel ( 0 , sdram_base ) ;
/*
* Initialization sequence for SDRAM , from the data sheet :
@ -77,7 +70,7 @@ unsigned long sdram_init(const struct sdram_info *info)
*/
hsdramc1_writel ( MR , HSDRAMC1_MODE_BANKS_PRECHARGE ) ;
hsdramc1_readl ( MR ) ;
writel ( 0 , sdram ) ;
writel ( 0 , sdram_base ) ;
/*
* 3. Eight auto - refresh ( CBR ) cycles are provided
@ -85,58 +78,41 @@ unsigned long sdram_init(const struct sdram_info *info)
hsdramc1_writel ( MR , HSDRAMC1_MODE_AUTO_REFRESH ) ;
hsdramc1_readl ( MR ) ;
for ( i = 0 ; i < 8 ; i + + )
writel ( 0 , sdram ) ;
writel ( 0 , sdram_base ) ;
/*
* 4. A mode register set ( MRS ) cycle is issued to program
* SDRAM parameters , in particular CAS latency and burst
* length .
*
* CAS from info struct , burst length 1 , serial burst type
* The address will be chosen by the SDRAMC automatically ; we
* just have to make sure BA [ 1 : 0 ] are set to 0.
*/
hsdramc1_writel ( MR , HSDRAMC1_MODE_LOAD_MODE ) ;
hsdramc1_readl ( MR ) ;
writel ( 0 , sdram + ( info - > cas < < 4 ) ) ;
writel ( 0 , sdram_base ) ;
/*
* 5. A Normal Mode command is provided , 3 clocks after tMRD
* is met .
*
* From the timing diagram , it looks like tMRD is 3
* cycles . . . try a dummy read from the peripheral bus .
* 5. The application must go into Normal Mode , setting Mode
* to 0 in the Mode Register and performing a write access
* at any location in the SDRAM .
*/
hsdramc1_readl ( MR ) ;
hsdramc1_writel ( MR , HSDRAMC1_MODE_NORMAL ) ;
hsdramc1_readl ( MR ) ;
writel ( 0 , sdram ) ;
writel ( 0 , sdram_base ) ;
/*
* 6. Write refresh rate into SDRAMC refresh timer count
* register ( refresh rate = timing between refresh cycles ) .
*
* 15.6 us is a typical value for a burst of length one
*/
bus_hz = get_sdram_clk_rate ( ) ;
hsdramc1_writel ( TR , info - > refresh_period ) ;
printf ( " SDRAM: %u MB at address 0x%08lx \n " ,
sdram_size > > 20 , info - > phys_addr ) ;
printf ( " Testing SDRAM... " ) ;
for ( i = 0 ; i < sdram_size / 4 ; i + + )
sdram [ i ] = i ;
for ( i = 0 ; i < sdram_size / 4 ; i + + ) {
tmp = sdram [ i ] ;
if ( tmp ! = i ) {
printf ( " FAILED at address 0x%08lx \n " ,
info - > phys_addr + i * 4 ) ;
printf ( " SDRAM: read 0x%lx, expected 0x%lx \n " , tmp , i ) ;
return 0 ;
}
}
puts ( " OK \n " ) ;
hsdramc1_writel ( TR , config - > refresh_period ) ;
if ( config - > data_bits = = SDRAM_DATA_16BIT )
sdram_size = 1 < < ( config - > row_bits + config - > col_bits
+ config - > bank_bits + 1 ) ;
else
sdram_size = 1 < < ( config - > row_bits + config - > col_bits
+ config - > bank_bits + 2 ) ;
return sdram_size ;
}
Haavard Skinnemoen
16 years ago