-
Notifications
You must be signed in to change notification settings - Fork 0
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
clk: tegra: Refactor fractional divider calculation
Move this to a separate file so it can be used to calculate the sdmmc clock dividers. Signed-off-by: Peter De-Schrijver <pdeschrijver@nvidia.com> Signed-off-by: Aapo Vienamo <avienamo@nvidia.com> Acked-by: Peter De Schrijver <pdeschrijver@nvidia.com> Acked-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Stephen Boyd <sboyd@kernel.org>
- Loading branch information
Peter De Schrijver
authored and
Stephen Boyd
committed
Jul 25, 2018
1 parent
0cbb61a
commit cb3ac59
Showing
4 changed files
with
52 additions
and
25 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Original file line number | Diff line number | Diff line change |
---|---|---|
@@ -0,0 +1,43 @@ | ||
// SPDX-License-Identifier: GPL-2.0 | ||
/* | ||
* Copyright (c) 2018, NVIDIA CORPORATION. All rights reserved. | ||
*/ | ||
|
||
#include <asm/div64.h> | ||
|
||
#include "clk.h" | ||
|
||
#define div_mask(w) ((1 << (w)) - 1) | ||
|
||
int div_frac_get(unsigned long rate, unsigned parent_rate, u8 width, | ||
u8 frac_width, u8 flags) | ||
{ | ||
u64 divider_ux1 = parent_rate; | ||
int mul; | ||
|
||
if (!rate) | ||
return 0; | ||
|
||
mul = 1 << frac_width; | ||
|
||
if (!(flags & TEGRA_DIVIDER_INT)) | ||
divider_ux1 *= mul; | ||
|
||
if (flags & TEGRA_DIVIDER_ROUND_UP) | ||
divider_ux1 += rate - 1; | ||
|
||
do_div(divider_ux1, rate); | ||
|
||
if (flags & TEGRA_DIVIDER_INT) | ||
divider_ux1 *= mul; | ||
|
||
if (divider_ux1 < mul) | ||
return 0; | ||
|
||
divider_ux1 -= mul; | ||
|
||
if (divider_ux1 > div_mask(width)) | ||
return div_mask(width); | ||
|
||
return divider_ux1; | ||
} |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters