ddr: altera: Clean up rw_mgr_mem_calibrate_writes()

Reorder the content of the function a little and fix the comments
so they at least become full sentences. Constify function args.
Fix the return value to match the common convention of 0 meaning
success.

Signed-off-by: Marek Vasut <marex@denx.de>

diff --git a/drivers/ddr/altera/sequencer.c b/drivers/ddr/altera/sequencer.c
index 0d1e6c8..714fdf0 100644 (file)
--- a/drivers/ddr/altera/sequencer.c
+++ b/drivers/ddr/altera/sequencer.c
@@ -3160,25 +3160,37 @@ static uint32_t rw_mgr_mem_calibrate_writes_center(uint32_t rank_bgn,
        return (dq_margin >= 0) && (dqs_margin >= 0) && (dm_margin >= 0);
 }
 
-/* calibrate the write operations */
-static uint32_t rw_mgr_mem_calibrate_writes(uint32_t rank_bgn, uint32_t g,
-       uint32_t test_bgn)
+/**
+ * rw_mgr_mem_calibrate_writes() - Write Calibration Part One
+ * @rank_bgn:          Rank number
+ * @group:             Read/Write Group
+ * @test_bgn:          Rank at which the test begins
+ *
+ * Stage 2: Write Calibration Part One.
+ *
+ * This function implements UniPHY calibration Stage 2, as explained in
+ * detail in Altera EMI_RM 2015.05.04 , "UniPHY Calibration Stages".
+ */
+static int rw_mgr_mem_calibrate_writes(const u32 rank_bgn, const u32 group,
+                                      const u32 test_bgn)
 {
-       /* update info for sims */
-       debug("%s:%d %u %u\n", __func__, __LINE__, g, test_bgn);
+       int ret;
+
+       /* Update info for sims */
+       debug("%s:%d %u %u\n", __func__, __LINE__, group, test_bgn);
 
+       reg_file_set_group(group);
        reg_file_set_stage(CAL_STAGE_WRITES);
        reg_file_set_sub_stage(CAL_SUBSTAGE_WRITES_CENTER);
 
-       reg_file_set_group(g);
-
-       if (!rw_mgr_mem_calibrate_writes_center(rank_bgn, g, test_bgn)) {
-               set_failing_group_stage(g, CAL_STAGE_WRITES,
+       ret = rw_mgr_mem_calibrate_writes_center(rank_bgn, group, test_bgn);
+       if (!ret) {
+               set_failing_group_stage(group, CAL_STAGE_WRITES,
                                        CAL_SUBSTAGE_WRITES_CENTER);
-               return 0;
+               return -EIO;
        }
 
-       return 1;
+       return 0;
 }
 
 /**
@@ -3472,7 +3484,7 @@ static uint32_t mem_calibrate(void)
                                        continue;
 
                                /* Calibrate WRITEs */
-                               if (rw_mgr_mem_calibrate_writes(rank_bgn,
+                               if (!rw_mgr_mem_calibrate_writes(rank_bgn,
                                                write_group, write_test_bgn))
                                        continue;