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8f90f43a09
pll0822x PLL is used in Exynos850 SoC for top-level integer PLLs. The
code was derived from very similar pll35xx type, with next differences:
1. Lock time for pll0822x is 150*P_DIV, when for pll35xx it's 270*P_DIV
2. It's not suggested in Exynos850 TRM that S_DIV change doesn't require
performing PLL lock procedure (which is done in pll35xx
implementation)
When defining pll0822x type, CON3 register offset should be provided as
a "con" parameter of PLL() macro, like this:
PLL(pll_0822x, 0, "fout_shared0_pll", "oscclk",
PLL_LOCKTIME_PLL_SHARED0, PLL_CON3_PLL_SHARED0,
exynos850_shared0_pll_rates),
To define PLL rates table, one can use PLL_35XX_RATE() macro, e.g.:
PLL_35XX_RATE(26 * MHZ, 1600 * MHZ, 800, 13, 0)
as it's completely appropriate for pl0822x type and there is no sense in
duplicating that.
If bit #1 (MANUAL_PLL_CTRL) is not set in CON1 register, it won't be
possible to set new rate, with next error showing in kernel log:
Could not lock PLL fout_shared1_pll
That can happen for example if bootloader clears that bit beforehand.
PLL driver doesn't account for that, so if MANUAL_PLL_CTRL bit was
cleared, it's assumed it was done for a reason and it shouldn't be
possible to change that PLL's rate at all.
Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Link: https://lore.kernel.org/r/20211008154352.19519-2-semen.protsenko@linaro.org
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
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In order to build the documentation, use ``make htmldocs`` or
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https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
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the problems which may result by upgrading your kernel.