ata: ahci_brcm: Fix use of BCM7216 reset controller

This driver may use one of two resets controllers.  Keep them in separate
variables to keep things simple.  The reset controller "rescal" is shared
between the AHCI driver and the PCIe driver for the BrcmSTB 7216 chip.  Use
devm_reset_control_get_optional_shared() to handle this sharing.

[bhelgaas: add Jens' ack from v5 posting]
Fixes: 272ecd60a6 ("ata: ahci_brcm: BCM7216 reset is self de-asserting")
Fixes: c345ec6a50 ("ata: ahci_brcm: Support BCM7216 reset controller name")
Link: https://lore.kernel.org/r/20210430152156.21162-3-jim2101024@gmail.com
Signed-off-by: Jim Quinlan <jim2101024@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>

drivers/ata/ahci_brcm.c

@@ -86,7 +86,8 @@ struct brcm_ahci_priv {
 	u32 port_mask;
 	u32 quirks;
 	enum brcm_ahci_version version;
-	struct reset_control *rcdev;
+	struct reset_control *rcdev_rescal;
+	struct reset_control *rcdev_ahci;
 };
 
 static inline u32 brcm_sata_readreg(void __iomem *addr)
@@ -352,8 +353,8 @@ static int brcm_ahci_suspend(struct device *dev)
 	else
 		ret = 0;
 
-	if (priv->version != BRCM_SATA_BCM7216)
-		reset_control_assert(priv->rcdev);
+	reset_control_assert(priv->rcdev_ahci);
+	reset_control_rearm(priv->rcdev_rescal);
 
 	return ret;
 }
@@ -365,10 +366,10 @@ static int __maybe_unused brcm_ahci_resume(struct device *dev)
 	struct brcm_ahci_priv *priv = hpriv->plat_data;
 	int ret = 0;
 
-	if (priv->version == BRCM_SATA_BCM7216)
-		ret = reset_control_reset(priv->rcdev);
-	else
-		ret = reset_control_deassert(priv->rcdev);
+	ret = reset_control_deassert(priv->rcdev_ahci);
+	if (ret)
+		return ret;
+	ret = reset_control_reset(priv->rcdev_rescal);
 	if (ret)
 		return ret;
 
@@ -434,7 +435,6 @@ static int brcm_ahci_probe(struct platform_device *pdev)
 {
 	const struct of_device_id *of_id;
 	struct device *dev = &pdev->dev;
-	const char *reset_name = NULL;
 	struct brcm_ahci_priv *priv;
 	struct ahci_host_priv *hpriv;
 	struct resource *res;
@@ -456,15 +456,15 @@ static int brcm_ahci_probe(struct platform_device *pdev)
 	if (IS_ERR(priv->top_ctrl))
 		return PTR_ERR(priv->top_ctrl);
 
-	/* Reset is optional depending on platform and named differently */
-	if (priv->version == BRCM_SATA_BCM7216)
-		reset_name = "rescal";
-	else
-		reset_name = "ahci";
-
-	priv->rcdev = devm_reset_control_get_optional(&pdev->dev, reset_name);
-	if (IS_ERR(priv->rcdev))
-		return PTR_ERR(priv->rcdev);
+	if (priv->version == BRCM_SATA_BCM7216) {
+		priv->rcdev_rescal = devm_reset_control_get_optional_shared(
+			&pdev->dev, "rescal");
+		if (IS_ERR(priv->rcdev_rescal))
+			return PTR_ERR(priv->rcdev_rescal);
+	}
+	priv->rcdev_ahci = devm_reset_control_get_optional(&pdev->dev, "ahci");
+	if (IS_ERR(priv->rcdev_ahci))
+		return PTR_ERR(priv->rcdev_ahci);
 
 	hpriv = ahci_platform_get_resources(pdev, 0);
 	if (IS_ERR(hpriv))
@@ -485,10 +485,10 @@ static int brcm_ahci_probe(struct platform_device *pdev)
 		break;
 	}
 
-	if (priv->version == BRCM_SATA_BCM7216)
-		ret = reset_control_reset(priv->rcdev);
-	else
-		ret = reset_control_deassert(priv->rcdev);
+	ret = reset_control_reset(priv->rcdev_rescal);
+	if (ret)
+		return ret;
+	ret = reset_control_deassert(priv->rcdev_ahci);
 	if (ret)
 		return ret;
 
@@ -539,8 +539,8 @@ out_disable_regulators:
 out_disable_clks:
 	ahci_platform_disable_clks(hpriv);
 out_reset:
-	if (priv->version != BRCM_SATA_BCM7216)
-		reset_control_assert(priv->rcdev);
+	reset_control_assert(priv->rcdev_ahci);
+	reset_control_rearm(priv->rcdev_rescal);
 	return ret;
 }