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| author | Sylwester Nawrocki <s.nawrocki@samsung.com> | 2017-07-21 13:19:50 +0200 |
|---|---|---|
| committer | Stephen Boyd <sboyd@codeaurora.org> | 2017-07-31 13:16:03 -0700 |
| commit | 5b30850bd6bda5188eedec60d364256617a87343 (patch) | |
| tree | ff5010155c5662f5ef0e96102b60a1a5b9548e41 /drivers/clk/samsung | |
| parent | d31fd43c0f9a41e2678a1e78c0f22f0384c6edd3 (diff) | |
| download | blackbird-obmc-linux-5b30850bd6bda5188eedec60d364256617a87343.tar.gz blackbird-obmc-linux-5b30850bd6bda5188eedec60d364256617a87343.zip | |
clk: samsung: exynos5420: The EPLL rate table corrections
This patch fixes values of the EPLL K coefficient and changes
the EPLL output frequency values to match exactly what is
possible to achieve with given M, P, S, K coefficients.
This allows to avoid rounding errors and unexpected frequency
being set with clk_set_rate(), due to recalc_rate returning
different values than the PLL rate specified in the
exynos5420_epll_24mhz_tbl table. E.g. this prevents a case
where two consecutive clk_set_rate() calls with same argument
result in different PLL output frequency.
The PLL output frequencies have been calculated with formula:
f = fxtal * (M * 2^16 + K) / (P * 2^S) / 2^16
where fxtal = 24000000.
Fixes: 9842452acd ("clk: samsung: exynos542x: Add EPLL rate table")
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Diffstat (limited to 'drivers/clk/samsung')
| -rw-r--r-- | drivers/clk/samsung/clk-exynos5420.c | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/drivers/clk/samsung/clk-exynos5420.c b/drivers/clk/samsung/clk-exynos5420.c index 0748a0b333c5..9a6476aa7d81 100644 --- a/drivers/clk/samsung/clk-exynos5420.c +++ b/drivers/clk/samsung/clk-exynos5420.c @@ -1283,16 +1283,16 @@ static const struct samsung_pll_rate_table exynos5420_pll2550x_24mhz_tbl[] __ini static const struct samsung_pll_rate_table exynos5420_epll_24mhz_tbl[] = { PLL_36XX_RATE(600000000U, 100, 2, 1, 0), PLL_36XX_RATE(400000000U, 200, 3, 2, 0), - PLL_36XX_RATE(393216000U, 197, 3, 2, 25690), - PLL_36XX_RATE(361267200U, 301, 5, 2, 3671), + PLL_36XX_RATE(393216003U, 197, 3, 2, -25690), + PLL_36XX_RATE(361267218U, 301, 5, 2, 3671), PLL_36XX_RATE(200000000U, 200, 3, 3, 0), - PLL_36XX_RATE(196608000U, 197, 3, 3, -25690), - PLL_36XX_RATE(180633600U, 301, 5, 3, 3671), - PLL_36XX_RATE(131072000U, 131, 3, 3, 4719), + PLL_36XX_RATE(196608001U, 197, 3, 3, -25690), + PLL_36XX_RATE(180633609U, 301, 5, 3, 3671), + PLL_36XX_RATE(131072006U, 131, 3, 3, 4719), PLL_36XX_RATE(100000000U, 200, 3, 4, 0), - PLL_36XX_RATE(65536000U, 131, 3, 4, 4719), - PLL_36XX_RATE(49152000U, 197, 3, 5, 25690), - PLL_36XX_RATE(32768000U, 131, 3, 5, 4719), + PLL_36XX_RATE( 65536003U, 131, 3, 4, 4719), + PLL_36XX_RATE( 49152000U, 197, 3, 5, -25690), + PLL_36XX_RATE( 32768001U, 131, 3, 5, 4719), }; static struct samsung_pll_clock exynos5x_plls[nr_plls] __initdata = { |
