OMAPDSS: DSS: add new clock calculation code
Add new way to iterate over DSS clock divisors. dss_div_calc() provides
a generic way to go over all the divisors, within given clock range.
dss_div_calc() will call a callback function for each divider set,
making the function reusable for all use cases.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
diff --git a/drivers/video/omap2/dss/dss.c b/drivers/video/omap2/dss/dss.c
index 054c2a2..eba4127 100644
--- a/drivers/video/omap2/dss/dss.c
+++ b/drivers/video/omap2/dss/dss.c
@@ -473,6 +473,45 @@
return 0;
}
+bool dss_div_calc(unsigned long fck_min, dss_div_calc_func func, void *data)
+{
+ int fckd, fckd_start, fckd_stop;
+ unsigned long fck;
+ unsigned long fck_hw_max;
+ unsigned long fckd_hw_max;
+ unsigned long prate;
+
+ if (dss.dpll4_m4_ck == NULL) {
+ /*
+ * TODO: dss1_fclk can be changed on OMAP2, but the available
+ * dividers are not continuous. We just use the pre-set rate for
+ * now.
+ */
+ fck = clk_get_rate(dss.dss_clk);
+ fckd = 1;
+ return func(fckd, fck, data);
+ }
+
+ fck_hw_max = dss_feat_get_param_max(FEAT_PARAM_DSS_FCK);
+ fckd_hw_max = dss.feat->fck_div_max;
+
+ prate = dss_get_dpll4_rate() * dss.feat->dss_fck_multiplier;
+
+ fck_min = fck_min ? fck_min : 1;
+
+ fckd_start = min(prate / fck_min, fckd_hw_max);
+ fckd_stop = max(DIV_ROUND_UP(prate, fck_hw_max), 1ul);
+
+ for (fckd = fckd_start; fckd >= fckd_stop; --fckd) {
+ fck = prate / fckd;
+
+ if (func(fckd, fck, data))
+ return true;
+ }
+
+ return false;
+}
+
int dss_set_clock_div(struct dss_clock_info *cinfo)
{
if (dss.dpll4_m4_ck) {