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[PATCH 4.3 066/125] clk: iproc: Fix PLL output frequency calculation

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  [PATCH 4.3 066/125] clk: iproc: Fix PLL output frequency calculation Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-12-07 16:10 +0100

#1285518 — [PATCH 4.3 066/125] clk: iproc: Fix PLL output frequency calculation

4.3-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Simran Rai <ssimran@broadcom.com>

commit 63243a4da7d0dfa19dcacd0a529782eeb2f86f92 upstream.

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@broadcom.com>
Signed-off-by: Ray Jui <rjui@broadcom.com>
Reviewed-by: Scott Branden <sbranden@broadcom.com>
Fixes: 5fe225c105fd ("clk: iproc: add initial common clock support")
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/clk/bcm/clk-iproc-pll.c |   13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

--- 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_ra
 	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_ra
 	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;


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