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exynos5420: Fix mmc clock source. 

The DWMMC controller internally divided clock by values in CLKSEL registers,
so we must adjust MMC clock for that.

Change-Id: I44f55b634cfc6fd81d76631595b6928c862a219f
Signed-off-by: Hung-Te Lin <hungte@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/66657
Commit-Queue: Ronald G. Minnich <rminnich@chromium.org>
Reviewed-by: Ronald G. Minnich <rminnich@chromium.org>
Tested-by: Ronald G. Minnich <rminnich@chromium.org>
Reviewed-by: David Hendricks <dhendrix@chromium.org>
(cherry picked from commit 89ed6c9154f16c6b8d01af03c0b78914773eb469)
Signed-off-by: Isaac Christensen <isaac.christensen@se-eng.com>
Reviewed-on: http://review.coreboot.org/6504
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
Reviewed-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
This commit is contained in:
Hung-Te Lin 2013-08-22 23:56:35 +08:00 committed by Isaac Christensen
parent d6b16f54b9
commit f2c4241b81
1 changed files with 18 additions and 5 deletions
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23
src/cpu/samsung/exynos5420/clock.c
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@ -333,16 +333,29 @@ int clock_set_dwmci(enum periph_id peripheral)
{ {
/* Request MMC clock value to 52MHz. */ /* Request MMC clock value to 52MHz. */
const unsigned long freq = 52000000; const unsigned long freq = 52000000;
unsigned long sclk, div; unsigned long sdclkin, cclkin;
int device_index = (int)peripheral - (int)PERIPH_ID_SDMMC0; int device_index = (int)peripheral - (int)PERIPH_ID_SDMMC0;
ASSERT(device_index >= 0 && device_index < 4); ASSERT(device_index >= 0 && device_index < 4);
sclk = get_mmc_clk(device_index); sdclkin = get_mmc_clk(device_index);
if (!sclk) { if (!sdclkin) {
return -1; return -1;
} }
div = CEIL_DIV(sclk, freq);
set_mmc_clk(device_index, div); /* The SDCLKIN is divided insided controller by the DIVRATIO field in
* CLKSEL register, so we must calculate clock value as
* cclk_in = SDCLKIN / (DIVRATIO + 1)
* Currently the RIVRATIO must be 3 for MMC0 and MMC2 on Exynos5420
* (and must be configured in payload).
*/
if (device_index == 0 || device_index == 2){
int divratio = 3;
sdclkin /= (divratio + 1);
}
printk(BIOS_DEBUG, "%s(%d): sdclkin: %ld\n", __func__, device_index, sdclkin);
cclkin = CEIL_DIV(sdclkin, freq);
set_mmc_clk(device_index, cclkin);
return 0; return 0;
} }