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| author | Haavard Skinnemoen <hskinnemoen@atmel.com> | 2008-01-23 17:20:14 +0100 |
|---|---|---|
| committer | Haavard Skinnemoen <hskinnemoen@atmel.com> | 2008-02-05 12:14:27 +0100 |
| commit | d38da537943cd36356b9d3d9d9b60533554b81d8 (patch) | |
| tree | 6263c715346047e4cda757dff839f4e1052652b7 /cpu | |
| parent | 61151cccb660cdb06a07fb283de6089913d7bde0 (diff) | |
| download | talos-obmc-uboot-d38da537943cd36356b9d3d9d9b60533554b81d8.tar.gz talos-obmc-uboot-d38da537943cd36356b9d3d9d9b60533554b81d8.zip | |
AVR32: Make SDRAM refresh rate configurable
The existing code assumes the SDRAM row refresh period should always
be 15.6 us. This is not always true, and indeed on the ATNGW100, the
refresh rate should really be 7.81 us.
Add a refresh_period member to struct sdram_info and initialize it
properly for both ATSTK1000 and ATNGW100. Out-of-tree boards will
panic() until the refresh_period member is updated properly.
Big thanks to Gerhard Berghofer for pointing out this issue.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Diffstat (limited to 'cpu')
| -rw-r--r-- | cpu/at32ap/hsdramc.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/cpu/at32ap/hsdramc.c b/cpu/at32ap/hsdramc.c index a936e03166..1fcfe75d74 100644 --- a/cpu/at32ap/hsdramc.c +++ b/cpu/at32ap/hsdramc.c @@ -38,6 +38,10 @@ unsigned long sdram_init(const struct sdram_info *info) unsigned long bus_hz; 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) @@ -113,7 +117,7 @@ unsigned long sdram_init(const struct sdram_info *info) * 15.6 us is a typical value for a burst of length one */ bus_hz = get_sdram_clk_rate(); - hsdramc1_writel(TR, (156 * (bus_hz / 1000)) / 10000); + hsdramc1_writel(TR, info->refresh_period); printf("SDRAM: %u MB at address 0x%08lx\n", sdram_size >> 20, info->phys_addr); |
