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From: Diogo Ivo <diogo.ivo@tecnico.ulisboa.pt>
To: krzysztof.kozlowski@linaro.org,
	thierry.reding@gmail.com,
	jonathanh@nvidia.com,
	linux-tegra@vger.kernel.org,
	linux-kernel@vger.kernel.org
Cc: Diogo Ivo <diogo.ivo@tecnico.ulisboa.pt>
Subject: [PATCH RESEND v3 6/7] memory: tegra: Move compare/update current delay values to a function
Date: Tue,  7 May 2024 10:30:49 +0100
Message-ID: <20240507093056.3921-7-diogo.ivo@tecnico.ulisboa.pt>
In-Reply-To: <20240507093056.3921-1-diogo.ivo@tecnico.ulisboa.pt>
References: <20240507093056.3921-1-diogo.ivo@tecnico.ulisboa.pt>
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Separate the comparison/updating of the measured delay values with the
values currently programmed into a separate function to simplify the
code.

Signed-off-by: Diogo Ivo <diogo.ivo@tecnico.ulisboa.pt>
---
Changes in v2:
 - Correct return value of update_clock_tree_delay() to bool

 drivers/memory/tegra/tegra210-emc-cc-r21021.c | 86 +++++++++----------
 1 file changed, 39 insertions(+), 47 deletions(-)

diff --git a/drivers/memory/tegra/tegra210-emc-cc-r21021.c b/drivers/memory/tegra/tegra210-emc-cc-r21021.c
index 9262da658189..a8a217502f0c 100644
--- a/drivers/memory/tegra/tegra210-emc-cc-r21021.c
+++ b/drivers/memory/tegra/tegra210-emc-cc-r21021.c
@@ -113,19 +113,35 @@ enum {
 #define __MOVAVG(timing, dev)                      \
 	((timing)->ptfv_list[(dev)])
 
-static u32 update_clock_tree_delay(struct tegra210_emc *emc, int type)
+static bool tegra210_emc_compare_update_delay(struct tegra210_emc_timing *timing,
+					      u32 measured, u32 idx)
+{
+	u32 *curr = &timing->current_dram_clktree[idx];
+	u32 rate_mhz = timing->rate / 1000;
+	u32 tmdel;
+
+	tmdel = abs(*curr - measured);
+
+	if (tmdel * 128 * rate_mhz / 1000000 > timing->tree_margin) {
+		*curr = measured;
+		return true;
+	}
+
+	return false;
+}
+
+static bool update_clock_tree_delay(struct tegra210_emc *emc, int type)
 {
 	bool periodic_training_update = type == PERIODIC_TRAINING_UPDATE;
 	struct tegra210_emc_timing *last = emc->last;
 	struct tegra210_emc_timing *next = emc->next;
 	u32 last_timing_rate_mhz = last->rate / 1000;
-	u32 next_timing_rate_mhz = next->rate / 1000;
 	bool dvfs_update = type == DVFS_UPDATE;
-	s32 tdel = 0, tmdel = 0, adel = 0;
 	bool dvfs_pt1 = type == DVFS_PT1;
 	u32 temp[2][2], value, delay_us;
 	unsigned long cval = 0;
 	unsigned int c, d, idx;
+	bool over = false;
 
 	if (dvfs_pt1 || periodic_training_update) {
 		delay_us = tegra210_emc_actual_osc_clocks(last->run_clocks);
@@ -174,17 +190,9 @@ static u32 update_clock_tree_delay(struct tegra210_emc *emc, int type)
 			else if (periodic_training_update)
 				__WEIGHTED_UPDATE_PTFV(idx, cval);
 
-			if (dvfs_update || periodic_training_update) {
-				tdel = next->current_dram_clktree[idx] -
-						__MOVAVG_AC(next, idx);
-				tmdel = (tdel < 0) ? -1 * tdel : tdel;
-				adel = tmdel;
-
-				if (tmdel * 128 * next_timing_rate_mhz / 1000000 >
-				    next->tree_margin)
-					next->current_dram_clktree[idx] =
-						__MOVAVG_AC(next, idx);
-			}
+			if (dvfs_update || periodic_training_update)
+				over |= tegra210_emc_compare_update_delay(next,
+							__MOVAVG_AC(next, idx), idx);
 
 			/* C[c]D[d]U[1] */
 			idx++;
@@ -202,34 +210,25 @@ static u32 update_clock_tree_delay(struct tegra210_emc *emc, int type)
 			else if (periodic_training_update)
 				__WEIGHTED_UPDATE_PTFV(idx, cval);
 
-			if (dvfs_update || periodic_training_update) {
-				tdel = next->current_dram_clktree[idx] -
-						__MOVAVG_AC(next, idx);
-				tmdel = (tdel < 0) ? -1 * tdel : tdel;
-
-				if (tmdel > adel)
-					adel = tmdel;
-
-				if (tmdel * 128 * next_timing_rate_mhz / 1000000 >
-				    next->tree_margin)
-					next->current_dram_clktree[idx] =
-						__MOVAVG_AC(next, idx);
-			}
+			if (dvfs_update || periodic_training_update)
+				over |= tegra210_emc_compare_update_delay(next,
+							__MOVAVG_AC(next, idx), idx);
 		}
 	}
 
-	return adel;
+	return over;
 }
 
-static u32 periodic_compensation_handler(struct tegra210_emc *emc, u32 type,
-					 struct tegra210_emc_timing *last,
-					 struct tegra210_emc_timing *next)
+static bool periodic_compensation_handler(struct tegra210_emc *emc, u32 type,
+					  struct tegra210_emc_timing *last,
+					  struct tegra210_emc_timing *next)
 {
 #define __COPY_EMA(nt, lt, dev)						\
 	({ __MOVAVG(nt, dev) = __MOVAVG(lt, dev) *			\
 	   (nt)->ptfv_list[PTFV_DVFS_SAMPLES_INDEX]; })
 
-	u32 i, adel = 0, samples = next->ptfv_list[PTFV_DVFS_SAMPLES_INDEX];
+	u32 i, samples = next->ptfv_list[PTFV_DVFS_SAMPLES_INDEX];
+	bool over = false;
 	u32 idx;
 
 	if (!next->periodic_training)
@@ -253,23 +252,23 @@ static u32 periodic_compensation_handler(struct tegra210_emc *emc, u32 type,
 
 			for (i = 0; i < samples; i++) {
 				/* Generate next sample of data. */
-				adel = update_clock_tree_delay(emc, DVFS_PT1);
+				update_clock_tree_delay(emc, DVFS_PT1);
 			}
 		}
 
 		/* Do the division part of the moving average */
-		adel = update_clock_tree_delay(emc, DVFS_UPDATE);
+		over = update_clock_tree_delay(emc, DVFS_UPDATE);
 	}
 
 	if (type == PERIODIC_TRAINING_SEQUENCE)
-		adel = update_clock_tree_delay(emc, PERIODIC_TRAINING_UPDATE);
+		over = update_clock_tree_delay(emc, PERIODIC_TRAINING_UPDATE);
 
-	return adel;
+	return over;
 }
 
 static u32 tegra210_emc_r21021_periodic_compensation(struct tegra210_emc *emc)
 {
-	u32 emc_cfg, emc_cfg_o, emc_cfg_update, del, value;
+	u32 emc_cfg, emc_cfg_o, emc_cfg_update, value;
 	static const u32 list[] = {
 		EMC_PMACRO_OB_DDLL_LONG_DQ_RANK0_0,
 		EMC_PMACRO_OB_DDLL_LONG_DQ_RANK0_1,
@@ -327,15 +326,12 @@ static u32 tegra210_emc_r21021_periodic_compensation(struct tegra210_emc *emc)
 		 * 4. Check delta wrt previous values (save value if margin
 		 *    exceeds what is set in table).
 		 */
-		del = periodic_compensation_handler(emc,
-						    PERIODIC_TRAINING_SEQUENCE,
-						    last, last);
-
+		if (periodic_compensation_handler(emc, PERIODIC_TRAINING_SEQUENCE,
+						  last, last)) {
 		/*
 		 * 5. Apply compensation w.r.t. trained values (if clock tree
 		 *    has drifted more than the set margin).
 		 */
-		if (last->tree_margin < ((del * 128 * (last->rate / 1000)) / 1000000)) {
 			for (i = 0; i < items; i++) {
 				value = tegra210_emc_compensate(last, list[i]);
 				emc_dbg(emc, EMA_WRITES, "0x%08x <= 0x%08x\n",
@@ -516,11 +512,7 @@ static void tegra210_emc_r21021_set_clock(struct tegra210_emc *emc, u32 clksrc)
 						     EMC_EMC_STATUS_DRAM_IN_SELF_REFRESH_MASK,
 						     0);
 
-		value = periodic_compensation_handler(emc, DVFS_SEQUENCE, fake,
-						      next);
-		value = (value * 128 * next->rate / 1000) / 1000000;
-
-		if (next->periodic_training && value > next->tree_margin)
+		if (periodic_compensation_handler(emc, DVFS_SEQUENCE, fake, next))
 			compensate_trimmer_applicable = true;
 	}
 
-- 
2.44.0