[PATCH v2] pinctrl: sunxi: request the per-bank supply optionally

[Yang Siyuan]

The per-bank "vcc-pX" supplies are optional in the device tree: the
binding documents them, but notes that many boards do not describe them.
sunxi_pmx_request() uses regulator_get() anyway, so the regulator core
falls back to a dummy regulator and warns for every bank that has no
supply:

  sun50i-h616-r-pinctrl 7022000.pinctrl: supply vcc-pl not found, using
  dummy regulator

The H616 R_PIO is such a controller, and its PL0/PL1 pins drive the
R_I2C bus, so every H616 board hits the warning during boot.

Use regulator_get_optional() instead.  A bank supply that is described
in the device tree is still acquired and enabled, as it powers the
physical VCC-Px rail, but one that is absent is skipped without a
warning.

Signed-off-by: Yang Siyuan <hsyysy at 163.com>
---

Changes in v2:
- Do not skip the supply on controllers without IO bias configuration:
  the per-bank regulator also powers the physical VCC-Px rail, so a
  supply described in the device tree must still be requested and
  enabled.  Use regulator_get_optional() so only banks that have no
  supply are skipped, which silences the warning without changing the
  power management behaviour.
- Link to v1: https://lore.kernel.org/linux-gpio/20261026144751.1392715-1-hsyysy@163.com/
---
 drivers/pinctrl/sunxi/pinctrl-sunxi.c | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/drivers/pinctrl/sunxi/pinctrl-sunxi.c b/drivers/pinctrl/sunxi/pinctrl-sunxi.c
index 70099052d..23c1fbd46 100644
--- a/drivers/pinctrl/sunxi/pinctrl-sunxi.c
+++ b/drivers/pinctrl/sunxi/pinctrl-sunxi.c
@@ -925,11 +925,19 @@ static int sunxi_pmx_request(struct pinctrl_dev *pctldev, unsigned offset)
 	}
 
 	snprintf(supply, sizeof(supply), "vcc-p%c", 'a' + bank);
-	reg = regulator_get(pctl->dev, supply);
-	if (IS_ERR(reg))
+	reg = regulator_get_optional(pctl->dev, supply);
+	if (IS_ERR(reg)) {
+		/*
+		 * The per-bank supply is optional: boards that do not
+		 * describe it simply have no regulator to manage.
+		 */
+		if (PTR_ERR(reg) == -ENODEV)
+			return 0;
+
 		return dev_err_probe(pctl->dev, PTR_ERR(reg),
 				     "Couldn't get bank P%c regulator\n",
 				     'A' + bank);
+	}
 
 	ret = regulator_enable(reg);
 	if (ret) {
@@ -959,6 +967,10 @@ static int sunxi_pmx_free(struct pinctrl_dev *pctldev, unsigned offset)
 					    PINS_PER_BANK;
 	struct sunxi_pinctrl_regulator *s_reg = &pctl->regulators[bank_offset];
 
+	/* The per-bank supply is optional, so this bank may not have one. */
+	if (!s_reg->regulator)
+		return 0;
+
 	if (!refcount_dec_and_test(&s_reg->refcount))
 		return 0;
 
base-commit: 091b06388b117fefdcb63336ac09956a4914b961
-- 
2.56.0