diff options
| author | David Hendricks <dhendrix@chromium.org> | 2013-08-06 15:17:37 -0700 |
|---|---|---|
| committer | Patrick Georgi <patrick@georgi-clan.de> | 2013-12-21 22:45:48 +0100 |
| commit | f05e8713007fa61f20dfa39a5176f8d5427cd673 (patch) | |
| tree | 363aaf2be3249b20232e5cea3efb942b5c865e39 /src/cpu/samsung/exynos5250 | |
| parent | 49c1be95d32f7106da2aef2c8f94709457081e7a (diff) | |
exynos5xxx: use oscillator clock when changing ARM frequency
Switch ARM clock source when changing the APLL frequency to avoid
stability issues.
This is ported from https://gerrit.chromium.org/gerrit/#/c/64189/5
Signed-off-by: David Hendricks <dhendrix@chromium.org>
Change-Id: I923107555e6d3287b3694cbf9e4bb548d3e5f4a8
Reviewed-on: https://gerrit.chromium.org/gerrit/64838
Reviewed-by: David Hendricks <dhendrix@chromium.org>
Tested-by: David Hendricks <dhendrix@chromium.org>
Commit-Queue: David Hendricks <dhendrix@chromium.org>
Reviewed-on: http://review.coreboot.org/4442
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <patrick@georgi-clan.de>
Diffstat (limited to 'src/cpu/samsung/exynos5250')
| -rw-r--r-- | src/cpu/samsung/exynos5250/clock_init.c | 6 | ||||
| -rw-r--r-- | src/cpu/samsung/exynos5250/setup.h | 2 |
2 files changed, 8 insertions, 0 deletions
diff --git a/src/cpu/samsung/exynos5250/clock_init.c b/src/cpu/samsung/exynos5250/clock_init.c index 2cfdaf4604..bfcf844b21 100644 --- a/src/cpu/samsung/exynos5250/clock_init.c +++ b/src/cpu/samsung/exynos5250/clock_init.c @@ -102,6 +102,9 @@ void system_clock_init(struct mem_timings *mem, val = readl(&clk->div_stat_cpu1); } while (0 != val); + /* switch A15 clock source to OSC clock before changing APLL */ + clrbits_le32(&clk->src_cpu, APLL_FOUT); + /* Set APLL */ writel(APLL_CON1_VAL, &clk->apll_con1); val = set_pll(arm_clk_ratio->apll_mdiv, arm_clk_ratio->apll_pdiv, @@ -110,6 +113,9 @@ void system_clock_init(struct mem_timings *mem, while ((readl(&clk->apll_con0) & APLL_CON0_LOCKED) == 0) ; + /* now it is safe to switch to APLL */ + setbits_le32(&clk->src_cpu, APLL_FOUT); + /* Set MPLL */ writel(MPLL_CON1_VAL, &clk->mpll_con1); val = set_pll(mem->mpll_mdiv, mem->mpll_pdiv, mem->mpll_sdiv); diff --git a/src/cpu/samsung/exynos5250/setup.h b/src/cpu/samsung/exynos5250/setup.h index 2ed4f2200e..c65747b775 100644 --- a/src/cpu/samsung/exynos5250/setup.h +++ b/src/cpu/samsung/exynos5250/setup.h @@ -38,6 +38,8 @@ struct exynos5_phy_control; #define TZPC8_BASE 0x10180000 #define TZPC9_BASE 0x10190000 +#define APLL_FOUT (1 << 0) + /* APLL_CON1 */ #define APLL_CON1_VAL (0x00203800) |