[PATCH] clk: imx: use sign_extend32() and abs()

From: Martin Kepplinger
Date: Tue Sep 29 2015 - 07:34:25 EST


This simplifies the given function by getting rid of the manual
sign extension as well as saving an absolute value in an extra
variable.

Signed-off-by: Martin Kepplinger <martink@xxxxxxxxx>
---
built and run, but please review.

martin


drivers/clk/imx/clk-pllv2.c | 12 ++++--------
1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/drivers/clk/imx/clk-pllv2.c b/drivers/clk/imx/clk-pllv2.c
index 20889d5..b18f875 100644
--- a/drivers/clk/imx/clk-pllv2.c
+++ b/drivers/clk/imx/clk-pllv2.c
@@ -77,7 +77,7 @@ struct clk_pllv2 {
static unsigned long __clk_pllv2_recalc_rate(unsigned long parent_rate,
u32 dp_ctl, u32 dp_op, u32 dp_mfd, u32 dp_mfn)
{
- long mfi, mfn, mfd, pdf, ref_clk, mfn_abs;
+ long mfi, mfn, mfd, pdf, ref_clk;
unsigned long dbl;
s64 temp;

@@ -87,19 +87,15 @@ static unsigned long __clk_pllv2_recalc_rate(unsigned long parent_rate,
mfi = (dp_op & MXC_PLL_DP_OP_MFI_MASK) >> MXC_PLL_DP_OP_MFI_OFFSET;
mfi = (mfi <= 5) ? 5 : mfi;
mfd = dp_mfd & MXC_PLL_DP_MFD_MASK;
- mfn = mfn_abs = dp_mfn & MXC_PLL_DP_MFN_MASK;
- /* Sign extend to 32-bits */
- if (mfn >= 0x04000000) {
- mfn |= 0xFC000000;
- mfn_abs = -mfn;
- }
+ mfn = dp_mfn & MXC_PLL_DP_MFN_MASK;
+ mfn = sign_extend32(mfn, 26);

ref_clk = 2 * parent_rate;
if (dbl != 0)
ref_clk *= 2;

ref_clk /= (pdf + 1);
- temp = (u64) ref_clk * mfn_abs;
+ temp = (u64) ref_clk * abs(mfn);
do_div(temp, mfd + 1);
if (mfn < 0)
temp = -temp;
--
2.1.4

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