Patch "regulator: pickable ranges: don't always cache vsel" has been added to the 6.8-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    regulator: pickable ranges: don't always cache vsel

to the 6.8-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     regulator-pickable-ranges-don-t-always-cache-vsel.patch
and it can be found in the queue-6.8 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 222d4a37a9314419806a1703bd16bf0e39e1f5b7
Author: Matti Vaittinen <mazziesaccount@xxxxxxxxx>
Date:   Mon May 20 15:31:33 2024 +0300

    regulator: pickable ranges: don't always cache vsel
    
    [ Upstream commit f4f4276f985a5aac7b310a4ed040b47e275e7591 ]
    
    Some PMICs treat the vsel_reg same as apply-bit. Eg, when voltage range
    is changed, the new voltage setting is not taking effect until the vsel
    register is written.
    
    Add a flag 'range_applied_by_vsel' to the regulator desc to indicate this
    behaviour and to force the vsel value to be written to hardware if range
    was changed, even if the old selector was same as the new one.
    
    Signed-off-by: Matti Vaittinen <mazziesaccount@xxxxxxxxx>
    Link: https://msgid.link/r/ZktCpcGZdgHWuN_L@fedora
    Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
    Stable-dep-of: 1ace99d7c7c4 ("regulator: tps6287x: Force writing VSEL bit")
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/regulator/helpers.c b/drivers/regulator/helpers.c
index d492683365532..6e1ace660b8cf 100644
--- a/drivers/regulator/helpers.c
+++ b/drivers/regulator/helpers.c
@@ -161,6 +161,32 @@ int regulator_get_voltage_sel_pickable_regmap(struct regulator_dev *rdev)
 }
 EXPORT_SYMBOL_GPL(regulator_get_voltage_sel_pickable_regmap);
 
+static int write_separate_vsel_and_range(struct regulator_dev *rdev,
+					 unsigned int sel, unsigned int range)
+{
+	bool range_updated;
+	int ret;
+
+	ret = regmap_update_bits_base(rdev->regmap, rdev->desc->vsel_range_reg,
+				      rdev->desc->vsel_range_mask,
+				      range, &range_updated, false, false);
+	if (ret)
+		return ret;
+
+	/*
+	 * Some PMICs treat the vsel_reg same as apply-bit. Force it to be
+	 * written if the range changed, even if the old selector was same as
+	 * the new one
+	 */
+	if (rdev->desc->range_applied_by_vsel && range_updated)
+		return regmap_write_bits(rdev->regmap,
+					rdev->desc->vsel_reg,
+					rdev->desc->vsel_mask, sel);
+
+	return regmap_update_bits(rdev->regmap, rdev->desc->vsel_reg,
+				  rdev->desc->vsel_mask, sel);
+}
+
 /**
  * regulator_set_voltage_sel_pickable_regmap - pickable range set_voltage_sel
  *
@@ -199,21 +225,12 @@ int regulator_set_voltage_sel_pickable_regmap(struct regulator_dev *rdev,
 	range = rdev->desc->linear_range_selectors_bitfield[i];
 	range <<= ffs(rdev->desc->vsel_range_mask) - 1;
 
-	if (rdev->desc->vsel_reg == rdev->desc->vsel_range_reg) {
-		ret = regmap_update_bits(rdev->regmap,
-					 rdev->desc->vsel_reg,
+	if (rdev->desc->vsel_reg == rdev->desc->vsel_range_reg)
+		ret = regmap_update_bits(rdev->regmap, rdev->desc->vsel_reg,
 					 rdev->desc->vsel_range_mask |
 					 rdev->desc->vsel_mask, sel | range);
-	} else {
-		ret = regmap_update_bits(rdev->regmap,
-					 rdev->desc->vsel_range_reg,
-					 rdev->desc->vsel_range_mask, range);
-		if (ret)
-			return ret;
-
-		ret = regmap_update_bits(rdev->regmap, rdev->desc->vsel_reg,
-				  rdev->desc->vsel_mask, sel);
-	}
+	else
+		ret = write_separate_vsel_and_range(rdev, sel, range);
 
 	if (ret)
 		return ret;
diff --git a/include/linux/regulator/driver.h b/include/linux/regulator/driver.h
index 22a07c0900a41..f230a472ccd35 100644
--- a/include/linux/regulator/driver.h
+++ b/include/linux/regulator/driver.h
@@ -299,6 +299,8 @@ enum regulator_type {
  * @vsel_range_reg: Register for range selector when using pickable ranges
  *		    and ``regulator_map_*_voltage_*_pickable`` functions.
  * @vsel_range_mask: Mask for register bitfield used for range selector
+ * @range_applied_by_vsel: A flag to indicate that changes to vsel_range_reg
+ *			   are only effective after vsel_reg is written
  * @vsel_reg: Register for selector when using ``regulator_map_*_voltage_*``
  * @vsel_mask: Mask for register bitfield used for selector
  * @vsel_step: Specify the resolution of selector stepping when setting
@@ -389,6 +391,7 @@ struct regulator_desc {
 
 	unsigned int vsel_range_reg;
 	unsigned int vsel_range_mask;
+	bool range_applied_by_vsel;
 	unsigned int vsel_reg;
 	unsigned int vsel_mask;
 	unsigned int vsel_step;