Add new way to iterate over DISPC clock divisors. dispc_div_calc()
provides a generic way to go over all the divisors, within given pixel
clock range. dispc_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@xxxxxx>
---
drivers/video/omap2/dss/dispc.c | 60 +++++++++++++++++++++++++++++++++++++++
drivers/video/omap2/dss/dss.h | 6 ++++
2 files changed, 66 insertions(+)
diff --git a/drivers/video/omap2/dss/dispc.c b/drivers/video/omap2/dss/dispc.c
index f564955..cd54e8f 100644
--- a/drivers/video/omap2/dss/dispc.c
+++ b/drivers/video/omap2/dss/dispc.c
@@ -3374,6 +3374,66 @@ int dispc_calc_clock_rates(unsigned long dispc_fclk_rate,
return 0;
}
+bool dispc_div_calc(unsigned long dispc,
+ unsigned long pck_min, unsigned long pck_max,
+ dispc_div_calc_func func, void *data)
+{
+ int lckd, lckd_start, lckd_stop;
+ int pckd, pckd_start, pckd_stop;
+ unsigned long pck, lck;
+ unsigned long lck_max;
+ unsigned long pckd_hw_min, pckd_hw_max;
+ unsigned min_fck_per_pck;
+ unsigned long fck;
+
+#ifdef CONFIG_OMAP2_DSS_MIN_FCK_PER_PCK
+ min_fck_per_pck = CONFIG_OMAP2_DSS_MIN_FCK_PER_PCK;
+#else
+ min_fck_per_pck = 0;
+#endif
+
+ pckd_hw_min = dss_feat_get_param_min(FEAT_PARAM_DSS_PCD);
+ pckd_hw_max = dss_feat_get_param_max(FEAT_PARAM_DSS_PCD);
+
+ lck_max = dss_feat_get_param_max(FEAT_PARAM_DSS_FCK);
+
+ pck_min = pck_min ? pck_min : 1;
+ pck_max = pck_max ? pck_max : ULONG_MAX;
+
+ lckd_start = max(DIV_ROUND_UP(dispc, lck_max), 1ul);
+ lckd_stop = min(dispc / pck_min, 255ul);
+
+ for (lckd = lckd_start; lckd <= lckd_stop; ++lckd) {
+ lck = dispc / lckd;
+
+ pckd_start = max(DIV_ROUND_UP(lck, pck_max), pckd_hw_min);
+ pckd_stop = min(lck / pck_min, pckd_hw_max);
+
+ for (pckd = pckd_start; pckd <= pckd_stop; ++pckd) {
+ pck = lck / pckd;
+
+ /*
+ * For OMAP2/3 the DISPC fclk is the same as LCD's logic
+ * clock, which means we're configuring DISPC fclk here
+ * also. Thus we need to use the calculated lck. For
+ * OMAP4+ the DISPC fclk is a separate clock.
+ */
+ if (dss_has_feature(FEAT_CORE_CLK_DIV))
+ fck = dispc_core_clk_rate();
+ else
+ fck = lck;
+
+ if (fck < pck * min_fck_per_pck)
+ continue;
+
+ if (func(lckd, pckd, lck, pck, data))
+ return true;
+ }
+ }
+
+ return false;
+}
+
void dispc_mgr_set_clock_div(enum omap_channel channel,
const struct dispc_clock_info *cinfo)
{
diff --git a/drivers/video/omap2/dss/dss.h b/drivers/video/omap2/dss/dss.h
index 610c8e5..0ff41dd 100644
--- a/drivers/video/omap2/dss/dss.h
+++ b/drivers/video/omap2/dss/dss.h
@@ -376,6 +376,12 @@ void dispc_enable_fifomerge(bool enable);
void dispc_enable_gamma_table(bool enable);
void dispc_set_loadmode(enum omap_dss_load_mode mode);
+typedef bool (*dispc_div_calc_func)(int lckd, int pckd, unsigned long lck,
+ unsigned long pck, void *data);
+bool dispc_div_calc(unsigned long dispc,
+ unsigned long pck_min, unsigned long pck_max,
+ dispc_div_calc_func func, void *data);
+
bool dispc_mgr_timings_ok(enum omap_channel channel,
const struct omap_video_timings *timings);
unsigned long dispc_fclk_rate(void);
--
1.7.10.4
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