On 12/13/18 7:46 PM, Jon Hunter wrote:

On 13/12/2018 09:34, Joseph Lo wrote:

quoted

When generating the OPP table, the voltages are round down with the
alignment from the regulator. The alignment should be applied for
voltages look up as well.

Based on the work of Penny Chiu [off-list ref].

Signed-off-by: Joseph Lo <redacted>
---
*V2:
  - s/align_volt/align_step/
  - s/reg_volt/reg_volt_id/
---
  drivers/clk/tegra/clk-dfll.c | 26 +++++++++++++++-----------
  1 file changed, 15 insertions(+), 11 deletions(-)

diff --git a/drivers/clk/tegra/clk-dfll.c b/drivers/clk/tegra/clk-dfll.c
index 72e02898006c..b3668073d9b4 100644
--- a/drivers/clk/tegra/clk-dfll.c
+++ b/drivers/clk/tegra/clk-dfll.c

@@ -804,17 +804,17 @@ static void dfll_init_out_if(struct tegra_dfll *td)
  static int find_lut_index_for_rate(struct tegra_dfll *td, unsigned long rate)
  {
  	struct dev_pm_opp *opp;
-	int i, uv;
+	int i, align_step;
  
  	opp = dev_pm_opp_find_freq_ceil(td->soc->dev, &rate);
  	if (IS_ERR(opp))
  		return PTR_ERR(opp);
  
-	uv = dev_pm_opp_get_voltage(opp);
+	align_step = dev_pm_opp_get_voltage(opp) / td->soc->alignment.step_uv;
  	dev_pm_opp_put(opp);
  
  	for (i = td->lut_bottom; i < td->lut_size; i++) {
-		if (td->lut_uv[i] >= uv)
+		if ((td->lut_uv[i] / td->soc->alignment.step_uv) >= align_step)
  			return i;
  	}
  

@@ -1532,15 +1532,17 @@ static int dfll_init(struct tegra_dfll *td)
   */
  static int find_vdd_map_entry_exact(struct tegra_dfll *td, int uV)
  {
-	int i, n_voltages, reg_uV;
+	int i, n_voltages, reg_volt_id, align_step;
  
+	align_step = uV / td->soc->alignment.step_uv;
  	n_voltages = regulator_count_voltages(td->vdd_reg);
  	for (i = 0; i < n_voltages; i++) {
-		reg_uV = regulator_list_voltage(td->vdd_reg, i);
-		if (reg_uV < 0)
+		reg_volt_id = regulator_list_voltage(td->vdd_reg, i) /
+			      td->soc->alignment.step_uv;
+		if (reg_volt_id < 0)

I don't think that this will work. If the step is say 10000 and we
return an error code greater than -10000, we will end up with 0.

Ah,I think you mean when the error code smaller than step_uv. Yes, it 
will be 0 in that case. I think I will just remove the 'if' clause, then 
it will not match anything and leave the for loop. And return error if 
it couldn't find anything. Same as below.

Thanks.

quoted

  			break;
  
-		if (uV == reg_uV)
+		if (align_step == reg_volt_id)
  			return i;
  	}
  

@@ -1554,15 +1556,17 @@ static int find_vdd_map_entry_exact(struct tegra_dfll *td, int uV)
   * */
  static int find_vdd_map_entry_min(struct tegra_dfll *td, int uV)
  {
-	int i, n_voltages, reg_uV;
+	int i, n_voltages, reg_volt_id, align_step;
  
+	align_step = uV / td->soc->alignment.step_uv;
  	n_voltages = regulator_count_voltages(td->vdd_reg);
  	for (i = 0; i < n_voltages; i++) {
-		reg_uV = regulator_list_voltage(td->vdd_reg, i);
-		if (reg_uV < 0)
+		reg_volt_id = regulator_list_voltage(td->vdd_reg, i) /
+			      td->soc->alignment.step_uv;
+		if (reg_volt_id < 0)

Same here.

quoted

  			break;
  
-		if (uV <= reg_uV)
+		if (align_step <= reg_volt_id)
  			return i;
  	}
  

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