[PATCH v2] clk: iproc: Fix PLL output frequency calculation

From: Ray Jui
Date: Mon Oct 19 2015 - 18:27:44 EST


From: Simran Rai <ssimran@xxxxxxxxxxxx>

This patch affects the clocks that use fractional ndivider in their
PLL output frequency calculation. Instead of 2^20 divide factor, the
clock's ndiv integer shift was used. Fixed the bug by replacing ndiv
integer shift with 2^20 factor.

Signed-off-by: Simran Rai <ssimran@xxxxxxxxxxxx>
Signed-off-by: Ray Jui <rjui@xxxxxxxxxxxx>
Reviewed-by: Scott Branden <sbranden@xxxxxxxxxxxx>
Fixes: 5fe225c105fd ("clk: iproc: add initial common clock support")
---
drivers/clk/bcm/clk-iproc-pll.c | 13 +++++--------
1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/drivers/clk/bcm/clk-iproc-pll.c b/drivers/clk/bcm/clk-iproc-pll.c
index 2dda4e8..d679ab8 100644
--- a/drivers/clk/bcm/clk-iproc-pll.c
+++ b/drivers/clk/bcm/clk-iproc-pll.c
@@ -345,8 +345,8 @@ static unsigned long iproc_pll_recalc_rate(struct clk_hw *hw,
struct iproc_pll *pll = clk->pll;
const struct iproc_pll_ctrl *ctrl = pll->ctrl;
u32 val;
- u64 ndiv;
- unsigned int ndiv_int, ndiv_frac, pdiv;
+ u64 ndiv, ndiv_int, ndiv_frac;
+ unsigned int pdiv;

if (parent_rate == 0)
return 0;
@@ -366,22 +366,19 @@ static unsigned long iproc_pll_recalc_rate(struct clk_hw *hw,
val = readl(pll->pll_base + ctrl->ndiv_int.offset);
ndiv_int = (val >> ctrl->ndiv_int.shift) &
bit_mask(ctrl->ndiv_int.width);
- ndiv = (u64)ndiv_int << ctrl->ndiv_int.shift;
+ ndiv = ndiv_int << 20;

if (ctrl->flags & IPROC_CLK_PLL_HAS_NDIV_FRAC) {
val = readl(pll->pll_base + ctrl->ndiv_frac.offset);
ndiv_frac = (val >> ctrl->ndiv_frac.shift) &
bit_mask(ctrl->ndiv_frac.width);
-
- if (ndiv_frac != 0)
- ndiv = ((u64)ndiv_int << ctrl->ndiv_int.shift) |
- ndiv_frac;
+ ndiv += ndiv_frac;
}

val = readl(pll->pll_base + ctrl->pdiv.offset);
pdiv = (val >> ctrl->pdiv.shift) & bit_mask(ctrl->pdiv.width);

- clk->rate = (ndiv * parent_rate) >> ctrl->ndiv_int.shift;
+ clk->rate = (ndiv * parent_rate) >> 20;

if (pdiv == 0)
clk->rate *= 2;
--
1.9.1

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