recipes-bsp/linux/linux-omap-psp-2.6.32/cam/0019-omap3isp-core-Do-smarter-MCLK-setting.patch

   1 From 97761e2bdf286662e3c96f5a24fe568cac98fc9b Mon Sep 17 00:00:00 2001
   2 From: Sergio Aguirre <saaguirre@ti.com>
   3 Date: Wed, 25 Nov 2009 12:30:46 -0600
   4 Subject: [PATCH 19/75] omap3isp: core: Do smarter MCLK setting
   5
   6 Since the ratio between MCLK and DPLL4_M5 could not be 1:1
   7 (i.e. on 3430 its 2:1), it's necessary to check ratio
   8 between those 2 first.
   9
  10 This should make MCLK setting more adequate to different
  11 chipsets.
  12
  13 Tested on Zoom2 (3430 ES3.1)
  14
  15 Signed-off-by: Sergio Aguirre <saaguirre@ti.com>
  16 ---
  17  drivers/media/video/isp/isp.c |   13 ++++++++++++-
  18  1 files changed, 12 insertions(+), 1 deletions(-)
  19
  20 diff --git a/drivers/media/video/isp/isp.c b/drivers/media/video/isp/isp.c
  21 index cf68720..29dd005 100644
  22 --- a/drivers/media/video/isp/isp.c
  23 +++ b/drivers/media/video/isp/isp.c
  24 @@ -2353,8 +2353,19 @@ int isp_enable_mclk(struct device *dev)
  25  {
  26         struct isp_device *isp = dev_get_drvdata(dev);
  27         int r;
  28 +       unsigned long curr_mclk, curr_dpll4_m5, ratio;
  29
  30 -       r = clk_set_rate(isp->dpll4_m5_ck, isp->mclk);
  31 +       /* Check ratio between DPLL4_M5 and CAM_MCLK */
  32 +       curr_mclk = clk_get_rate(isp->cam_mclk);
  33 +       curr_dpll4_m5 = clk_get_rate(isp->dpll4_m5_ck);
  34 +
  35 +       /* Protection for potential Zero division, or zero-ratio result */
  36 +       if (!curr_mclk || !curr_dpll4_m5)
  37 +               BUG();
  38 +
  39 +       ratio = curr_mclk / curr_dpll4_m5;
  40 +
  41 +       r = clk_set_rate(isp->dpll4_m5_ck, isp->mclk / ratio);
  42                 if (r) {
  43                         dev_err(dev, "clk_set_rate for dpll4_m5_ck failed\n");
  44                         return r;
  45 --
  46 1.6.6.1
  47