drm/i915/cdclk: Extract cdclk_divider()

Extract the cdclk divider calculation into a helper. We'll have
more users of this soon. We can now also get rid of the intermediate
'unsquashed_cdclk' variable.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240207013334.29606-2-ville.syrjala@linux.intel.com
Reviewed-by: Gustavo Sousa <gustavo.sousa@intel.com>

diff --git a/drivers/gpu/drm/i915/display/intel_cdclk.c b/drivers/gpu/drm/i915/display/intel_cdclk.c
index 26200ee3e23f9fed708b5764b4f06a4aa4a7037a..d79485e17ed1baa91e98300bac91af55489104d9 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_cdclk.c
+++ b/drivers/gpu/drm/i915/display/intel_cdclk.c
@@ -1406,6 +1406,20 @@ static const struct intel_cdclk_vals lnl_cdclk_table[] = {
        {}
 };
 
+static const int cdclk_squash_len = 16;
+
+static int cdclk_squash_divider(u16 waveform)
+{
+       return hweight16(waveform ?: 0xffff);
+}
+
+static int cdclk_divider(int cdclk, int vco, u16 waveform)
+{
+       /* 2 * cd2x divider */
+       return DIV_ROUND_CLOSEST(vco * cdclk_squash_divider(waveform),
+                                cdclk * cdclk_squash_len);
+}
+
 static int bxt_calc_cdclk(struct drm_i915_private *dev_priv, int min_cdclk)
 {
        const struct intel_cdclk_vals *table = dev_priv->display.cdclk.table;
@@ -1744,10 +1758,10 @@ static u32 bxt_cdclk_cd2x_pipe(struct drm_i915_private *dev_priv, enum pipe pipe
 }
 
 static u32 bxt_cdclk_cd2x_div_sel(struct drm_i915_private *dev_priv,
-                                 int cdclk, int vco)
+                                 int cdclk, int vco, u16 waveform)
 {
        /* cdclk = vco / 2 / div{1,1.5,2,4} */
-       switch (DIV_ROUND_CLOSEST(vco, cdclk)) {
+       switch (cdclk_divider(cdclk, vco, waveform)) {
        default:
                drm_WARN_ON(&dev_priv->drm,
                            cdclk != dev_priv->display.cdclk.hw.bypass);
@@ -1826,13 +1840,6 @@ static bool cdclk_pll_is_unknown(unsigned int vco)
        return vco == ~0;
 }
 
-static const int cdclk_squash_len = 16;
-
-static int cdclk_squash_divider(u16 waveform)
-{
-       return hweight16(waveform ?: 0xffff);
-}
-
 static bool cdclk_compute_crawl_and_squash_midpoint(struct drm_i915_private *i915,
                                                    const struct intel_cdclk_config *old_cdclk_config,
                                                    const struct intel_cdclk_config *new_cdclk_config,
@@ -1906,16 +1913,12 @@ static u32 bxt_cdclk_ctl(struct drm_i915_private *i915,
 {
        int cdclk = cdclk_config->cdclk;
        int vco = cdclk_config->vco;
-       int unsquashed_cdclk;
        u16 waveform;
        u32 val;
 
        waveform = cdclk_squash_waveform(i915, cdclk);
 
-       unsquashed_cdclk = DIV_ROUND_CLOSEST(cdclk * cdclk_squash_len,
-                                            cdclk_squash_divider(waveform));
-
-       val = bxt_cdclk_cd2x_div_sel(i915, unsquashed_cdclk, vco) |
+       val = bxt_cdclk_cd2x_div_sel(i915, cdclk, vco, waveform) |
                bxt_cdclk_cd2x_pipe(i915, pipe);
 
        /*