linux-kernel - [PATCH v1 2/2] PCI: dwc: histb: Simplify reset control handling by using reset_control

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Message-ID: <20250826114245.112472-3-linux.amoon@gmail.com>
Date: Tue, 26 Aug 2025 17:12:41 +0530
From: Anand Moon <linux.amoon@...il.com>
To: Shawn Guo <shawn.guo@...aro.org>,
	Lorenzo Pieralisi <lpieralisi@...nel.org>,
	Krzysztof Wilczyński <kwilczynski@...nel.org>,
	Manivannan Sadhasivam <mani@...nel.org>,
	Rob Herring <robh@...nel.org>,
	Bjorn Helgaas <bhelgaas@...gle.com>,
	Philipp Zabel <p.zabel@...gutronix.de>,
	linux-pci@...r.kernel.org (open list:PCIE DRIVER FOR HISILICON STB),
	linux-kernel@...r.kernel.org (open list)
Cc: Anand Moon <linux.amoon@...il.com>
Subject: [PATCH v1 2/2] PCI: dwc: histb: Simplify reset control handling by using reset_control_bulk*() function

Currently, the driver acquires and asserts/deasserts the resets
individually thereby making the driver complex to read.

This can be simplified by using the reset_control_bulk() APIs.

Use devm_reset_control_bulk_get_exclusive() API to acquire all the resets
and use reset_control_bulk_{assert/deassert}() APIs to assert/deassert them
in bulk.

Signed-off-by: Anand Moon <linux.amoon@...il.com>
---
 drivers/pci/controller/dwc/pcie-histb.c | 57 ++++++++++++-------------
 1 file changed, 28 insertions(+), 29 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-histb.c b/drivers/pci/controller/dwc/pcie-histb.c
index 4022349e85d2..4ba5c9af63a0 100644
--- a/drivers/pci/controller/dwc/pcie-histb.c
+++ b/drivers/pci/controller/dwc/pcie-histb.c
@@ -49,14 +49,20 @@
 #define PCIE_LTSSM_STATE_MASK		GENMASK(5, 0)
 #define PCIE_LTSSM_STATE_ACTIVE		0x11
 
+#define PCIE_HISTB_NUM_RESETS   ARRAY_SIZE(histb_pci_rsts)
+
+static const char * const histb_pci_rsts[] = {
+	"soft",
+	"sys",
+	"bus",
+};
+
 struct histb_pcie {
 	struct dw_pcie *pci;
 	struct  clk_bulk_data *clks;
 	int     num_clks;
 	struct phy *phy;
-	struct reset_control *soft_reset;
-	struct reset_control *sys_reset;
-	struct reset_control *bus_reset;
+	struct  reset_control_bulk_data reset[PCIE_HISTB_NUM_RESETS];
 	void __iomem *ctrl;
 	struct gpio_desc *reset_gpio;
 	struct regulator *vpcie;
@@ -198,9 +204,8 @@ static const struct dw_pcie_host_ops histb_pcie_host_ops = {
 
 static void histb_pcie_host_disable(struct histb_pcie *hipcie)
 {
-	reset_control_assert(hipcie->soft_reset);
-	reset_control_assert(hipcie->sys_reset);
-	reset_control_assert(hipcie->bus_reset);
+	reset_control_bulk_assert(PCIE_HISTB_NUM_RESETS,
+				  hipcie->reset);
 
 	clk_bulk_disable_unprepare(hipcie->num_clks, hipcie->clks);
 
@@ -236,14 +241,19 @@ static int histb_pcie_host_enable(struct dw_pcie_rp *pp)
 		goto reg_dis;
 	}
 
-	reset_control_assert(hipcie->soft_reset);
-	reset_control_deassert(hipcie->soft_reset);
-
-	reset_control_assert(hipcie->sys_reset);
-	reset_control_deassert(hipcie->sys_reset);
+	ret = reset_control_bulk_assert(PCIE_HISTB_NUM_RESETS,
+					hipcie->reset);
+	if (ret) {
+		dev_err(dev, "Couldn't assert reset %d\n", ret);
+		goto reg_dis;
+	}
 
-	reset_control_assert(hipcie->bus_reset);
-	reset_control_deassert(hipcie->bus_reset);
+	ret = reset_control_bulk_deassert(PCIE_HISTB_NUM_RESETS,
+					  hipcie->reset);
+	if (ret) {
+		dev_err(dev, "Couldn't dessert reset %d\n", ret);
+		goto reg_dis;
+	}
 
 	return 0;
 
@@ -321,23 +331,12 @@ static int histb_pcie_probe(struct platform_device *pdev)
 		return dev_err_probe(dev, hipcie->num_clks,
 				     "failed to get clocks\n");
 
-	hipcie->soft_reset = devm_reset_control_get(dev, "soft");
-	if (IS_ERR(hipcie->soft_reset)) {
-		dev_err(dev, "couldn't get soft reset\n");
-		return PTR_ERR(hipcie->soft_reset);
-	}
+	ret = devm_reset_control_bulk_get_exclusive(dev,
+						    PCIE_HISTB_NUM_RESETS,
+						    hipcie->reset);
+	if (ret)
+		return dev_err_probe(dev, ret, "Cannot get the Core resets\n");
 
-	hipcie->sys_reset = devm_reset_control_get(dev, "sys");
-	if (IS_ERR(hipcie->sys_reset)) {
-		dev_err(dev, "couldn't get sys reset\n");
-		return PTR_ERR(hipcie->sys_reset);
-	}
-
-	hipcie->bus_reset = devm_reset_control_get(dev, "bus");
-	if (IS_ERR(hipcie->bus_reset)) {
-		dev_err(dev, "couldn't get bus reset\n");
-		return PTR_ERR(hipcie->bus_reset);
-	}
 
 	hipcie->phy = devm_phy_get(dev, "phy");
 	if (IS_ERR(hipcie->phy)) {
-- 
2.50.1