[PATCH 2/2] power: sequencing: pcie-m2: Add 3.3Vaux supply support

[Sherry Sun (OSS)]

From: Sherry Sun <sherry.sun@xxxxxxx>

Add 3.3Vaux separately for special handling. This supply has a different
lifecycle - it must remain enabled during system suspend to support PCIe
L2 link state and wake-up mechanisms.

Signed-off-by: Sherry Sun <sherry.sun@xxxxxxx>
---
 drivers/power/sequencing/pwrseq-pcie-m2.c | 42 ++++++++++++++++++++++-
 1 file changed, 41 insertions(+), 1 deletion(-)

diff --git a/drivers/power/sequencing/pwrseq-pcie-m2.c b/drivers/power/sequencing/pwrseq-pcie-m2.c
index e82821655fc4..6b8c77cf20a9 100644
--- a/drivers/power/sequencing/pwrseq-pcie-m2.c
+++ b/drivers/power/sequencing/pwrseq-pcie-m2.c
@@ -37,6 +37,8 @@ struct pwrseq_pcie_m2_ctx {
 	const struct pwrseq_pcie_m2_pdata *pdata;
 	struct regulator_bulk_data *regs;
 	size_t num_vregs;
+	struct regulator *vaux_reg;
+	bool vaux_enabled;
 	struct notifier_block nb;
 	struct gpio_desc *w_disable1_gpio;
 	struct gpio_desc *w_disable2_gpio;
@@ -48,8 +50,23 @@ struct pwrseq_pcie_m2_ctx {
 static int pwrseq_pcie_m2_vregs_enable(struct pwrseq_device *pwrseq)
 {
 	struct pwrseq_pcie_m2_ctx *ctx = pwrseq_device_get_drvdata(pwrseq);
+	int ret;
+
+	/* Enable 3.3Vaux if present and not already enabled. */
+	if (ctx->vaux_reg && !ctx->vaux_enabled) {
+		ret = regulator_enable(ctx->vaux_reg);
+		if (ret)
+			return ret;
+		ctx->vaux_enabled = true;
+	}
 
-	return regulator_bulk_enable(ctx->num_vregs, ctx->regs);
+	ret = regulator_bulk_enable(ctx->num_vregs, ctx->regs);
+	if (ret && ctx->vaux_reg && ctx->vaux_enabled) {
+		regulator_disable(ctx->vaux_reg);
+		ctx->vaux_enabled = false;
+	}
+
+	return ret;
 }
 
 static int pwrseq_pcie_m2_vregs_disable(struct pwrseq_device *pwrseq)
@@ -497,10 +514,28 @@ static int pwrseq_pcie_m2_probe(struct platform_device *pdev)
 		return dev_err_probe(dev, -ENODEV,
 				     "Failed to obtain platform data\n");
 
+	/*
+	 * Get 3.3Vaux separately for special handling. This supply has a
+	 * different lifecycle - it must remain enabled during system suspend
+	 * to support PCIe L2 link state and wake-up mechanisms.
+	 */
+	ctx->vaux_reg = devm_regulator_get_optional(dev, "vpcie3v3aux");
+	if (IS_ERR(ctx->vaux_reg)) {
+		if (PTR_ERR(ctx->vaux_reg) != -ENODEV)
+			return PTR_ERR(ctx->vaux_reg);
+		ctx->vaux_reg = NULL;
+	}
+	ctx->vaux_enabled = false;
+
 	/*
 	 * Currently, of_regulator_bulk_get_all() is the only regulator API that
 	 * allows to get all supplies in the devicetree node without manually
 	 * specifying them.
+	 *
+	 * This will include vaux again, but we'll manage it separately via
+	 * vaux_reg. The regulator framework handles multiple gets of the same
+	 * regulator correctly via refcounting, so having vaux in both places is
+	 * safe.
 	 */
 	ret = of_regulator_bulk_get_all(dev, dev_of_node(dev), &ctx->regs);
 	if (ret < 0)
@@ -573,6 +608,11 @@ static void pwrseq_pcie_m2_remove(struct platform_device *pdev)
 	pwrseq_pcie_m2_remove_serdev(ctx, NULL);
 	mutex_destroy(&ctx->list_lock);
 
+	if (ctx->vaux_reg && ctx->vaux_enabled) {
+		regulator_disable(ctx->vaux_reg);
+		ctx->vaux_enabled = false;
+	}
+
 	regulator_bulk_free(ctx->num_vregs, ctx->regs);
 }
 
-- 
2.50.1