From a61dc139ceb5e9f0b2033fd1075ec68b53b14283 Mon Sep 17 00:00:00 2001 From: Mike Rapoport Date: Thu, 22 Oct 2015 09:38:40 +0300 Subject: [PATCH] staging: sm750fb: simplify PLL divisors calculations The calcPllValues currently uses arrays of PLL parametres that contain possible PLL control register field values and redundant data that is calculated according to those values. The usage of these arrays can be replaced with simple arithmetics. Signed-off-by: Mike Rapoport Signed-off-by: Greg Kroah-Hartman --- drivers/staging/sm750fb/ddk750_chip.c | 44 ++++++--------------------- 1 file changed, 10 insertions(+), 34 deletions(-) diff --git a/drivers/staging/sm750fb/ddk750_chip.c b/drivers/staging/sm750fb/ddk750_chip.c index 069d6e57d7a7..7084a4a41042 100644 --- a/drivers/staging/sm750fb/ddk750_chip.c +++ b/drivers/staging/sm750fb/ddk750_chip.c @@ -303,33 +303,14 @@ int ddk750_initHw(initchip_param_t *pInitParam) */ unsigned int calcPllValue(unsigned int request_orig, pll_value_t *pll) { - /* used for primary and secondary channel pixel clock pll */ - static pllcalparam xparm_PIXEL[] = { - /* 2^0 = 1*/ {0, 0, 0, 1}, - /* 2^ 1 =2*/ {1, 0, 1, 2}, - /* 2^ 2 = 4*/ {2, 0, 2, 4}, - {3, 0, 3, 8}, - {4, 1, 3, 16}, - {5, 2, 3, 32}, - /* 2^6 = 64 */ {6, 3, 3, 64}, - }; - - /* used for MXCLK (chip clock) */ - static pllcalparam xparm_MXCLK[] = { - /* 2^0 = 1*/ {0, 0, 0, 1}, - /* 2^ 1 =2*/ {1, 0, 1, 2}, - /* 2^ 2 = 4*/ {2, 0, 2, 4}, - {3, 0, 3, 8}, - }; - /* as sm750 register definition, N located in 2,15 and M located in 1,255 */ int N, M, X, d; - int xcnt; int mini_diff; unsigned int RN, quo, rem, fl_quo; unsigned int input, request; unsigned int tmpClock, ret; - pllcalparam *xparm; + const int max_OD = 3; + int max_d; if (getChipType() == SM750LE) { /* SM750LE don't have prgrammable PLL and M/N values to work on. @@ -343,15 +324,8 @@ unsigned int calcPllValue(unsigned int request_orig, pll_value_t *pll) input = pll->inputFreq / 1000; /* for MXCLK register , no POD provided, so need be treated differently */ - - if (pll->clockType != MXCLK_PLL) { - xparm = &xparm_PIXEL[0]; - xcnt = ARRAY_SIZE(xparm_PIXEL); - } else { - xparm = &xparm_MXCLK[0]; - xcnt = ARRAY_SIZE(xparm_MXCLK); - } - + if (pll->clockType == MXCLK_PLL) + max_d = 3; for (N = 15; N > 1; N--) { /* RN will not exceed maximum long if @request <= 285 MHZ (for 32bit cpu) */ @@ -360,8 +334,8 @@ unsigned int calcPllValue(unsigned int request_orig, pll_value_t *pll) rem = RN % input;/* rem always small than 14318181 */ fl_quo = (rem * 10000 / input); - for (d = xcnt - 1; d >= 0; d--) { - X = xparm[d].value; + for (d = max_d; d >= 0; d--) { + X = (1 << d); M = quo * X; M += fl_quo * X / 10000; /* round step */ @@ -374,8 +348,10 @@ unsigned int calcPllValue(unsigned int request_orig, pll_value_t *pll) if (diff < mini_diff) { pll->M = M; pll->N = N; - pll->OD = xparm[d].od; - pll->POD = xparm[d].pod; + pll->POD = 0; + if (d > max_OD) + pll->POD = d - max_OD; + pll->OD = d - pll->POD; mini_diff = diff; ret = tmpClock; }