PCI: mediatek-gen3: Rely on reset_bulk APIs for PHY reset lines

Use reset_bulk APIs to manage PHY reset lines.

This is a preliminary patch in order to add Airoha EN7581 PCIe support.

Link: https://lore.kernel.org/linux-pci/3ceb83bc0defbcf868521f8df4b9100e55ec2614.1720022580.git.lorenzo@kernel.org
Signed-off-by: Lorenzo Bianconi <[email protected]>
Signed-off-by: Krzysztof Wilczyński <[email protected]>
Tested-by: Zhengping Zhang <[email protected]>
Reviewed-by: AngeloGioacchino Del Regno <[email protected]>
Acked-by: Jianjun Wang <[email protected]>

Author: LorenzoBianconi

drivers/pci/controller/pcie-mediatek-gen3.c

@@ -100,14 +100,21 @@
 #define PCIE_ATR_TLP_TYPE_MEM		PCIE_ATR_TLP_TYPE(0)
 #define PCIE_ATR_TLP_TYPE_IO		PCIE_ATR_TLP_TYPE(2)
 
+#define MAX_NUM_PHY_RESETS		1
+
 struct mtk_gen3_pcie;
 
 /**
  * struct mtk_gen3_pcie_pdata - differentiate between host generations
  * @power_up: pcie power_up callback
+ * @phy_resets: phy reset lines SoC data.
  */
 struct mtk_gen3_pcie_pdata {
 	int (*power_up)(struct mtk_gen3_pcie *pcie);
+	struct {
+		const char *id[MAX_NUM_PHY_RESETS];
+		int num_resets;
+	} phy_resets;
 };
 
 /**
@@ -128,7 +135,7 @@ struct mtk_msi_set {
  * @base: IO mapped register base
  * @reg_base: physical register base
  * @mac_reset: MAC reset control
- * @phy_reset: PHY reset control
+ * @phy_resets: PHY reset controllers
  * @phy: PHY controller block
  * @clks: PCIe clocks
  * @num_clks: PCIe clocks count for this port
@@ -148,7 +155,7 @@ struct mtk_gen3_pcie {
 	void __iomem *base;
 	phys_addr_t reg_base;
 	struct reset_control *mac_reset;
-	struct reset_control *phy_reset;
+	struct reset_control_bulk_data phy_resets[MAX_NUM_PHY_RESETS];
 	struct phy *phy;
 	struct clk_bulk_data *clks;
 	int num_clks;
@@ -788,10 +795,10 @@ static int mtk_pcie_setup_irq(struct mtk_gen3_pcie *pcie)
 
 static int mtk_pcie_parse_port(struct mtk_gen3_pcie *pcie)
 {
+	int i, ret, num_resets = pcie->soc->phy_resets.num_resets;
 	struct device *dev = pcie->dev;
 	struct platform_device *pdev = to_platform_device(dev);
 	struct resource *regs;
-	int ret;
 
 	regs = platform_get_resource_byname(pdev, IORESOURCE_MEM, "pcie-mac");
 	if (!regs)
@@ -804,12 +811,12 @@ static int mtk_pcie_parse_port(struct mtk_gen3_pcie *pcie)
 
 	pcie->reg_base = regs->start;
 
-	pcie->phy_reset = devm_reset_control_get_optional_exclusive(dev, "phy");
-	if (IS_ERR(pcie->phy_reset)) {
-		ret = PTR_ERR(pcie->phy_reset);
-		if (ret != -EPROBE_DEFER)
-			dev_err(dev, "failed to get PHY reset\n");
+	for (i = 0; i < num_resets; i++)
+		pcie->phy_resets[i].id = pcie->soc->phy_resets.id[i];
 
+	ret = devm_reset_control_bulk_get_optional_shared(dev, num_resets, pcie->phy_resets);
+	if (ret) {
+		dev_err(dev, "failed to get PHY bulk reset\n");
 		return ret;
 	}
 
@@ -846,7 +853,11 @@ static int mtk_pcie_power_up(struct mtk_gen3_pcie *pcie)
 	int err;
 
 	/* PHY power on and enable pipe clock */
-	reset_control_deassert(pcie->phy_reset);
+	err = reset_control_bulk_deassert(pcie->soc->phy_resets.num_resets, pcie->phy_resets);
+	if (err) {
+		dev_err(dev, "failed to deassert PHYs\n");
+		return err;
+	}
 
 	err = phy_init(pcie->phy);
 	if (err) {
@@ -882,7 +893,7 @@ static int mtk_pcie_power_up(struct mtk_gen3_pcie *pcie)
 err_phy_on:
 	phy_exit(pcie->phy);
 err_phy_init:
-	reset_control_assert(pcie->phy_reset);
+	reset_control_bulk_assert(pcie->soc->phy_resets.num_resets, pcie->phy_resets);
 
 	return err;
 }
@@ -897,7 +908,7 @@ static void mtk_pcie_power_down(struct mtk_gen3_pcie *pcie)
 
 	phy_power_off(pcie->phy);
 	phy_exit(pcie->phy);
-	reset_control_assert(pcie->phy_reset);
+	reset_control_bulk_assert(pcie->soc->phy_resets.num_resets, pcie->phy_resets);
 }
 
 static int mtk_pcie_setup(struct mtk_gen3_pcie *pcie)
@@ -908,11 +919,17 @@ static int mtk_pcie_setup(struct mtk_gen3_pcie *pcie)
 	if (err)
 		return err;
 
+	/*
+	 * Deassert the line in order to avoid unbalance in deassert_count
+	 * counter since the bulk is shared.
+	 */
+	reset_control_bulk_deassert(pcie->soc->phy_resets.num_resets, pcie->phy_resets);
 	/*
 	 * The controller may have been left out of reset by the bootloader
 	 * so make sure that we get a clean start by asserting resets here.
 	 */
-	reset_control_assert(pcie->phy_reset);
+	reset_control_bulk_assert(pcie->soc->phy_resets.num_resets, pcie->phy_resets);
+
 	reset_control_assert(pcie->mac_reset);
 	usleep_range(10, 20);
 
@@ -1090,6 +1107,10 @@ static const struct dev_pm_ops mtk_pcie_pm_ops = {
 
 static const struct mtk_gen3_pcie_pdata mtk_pcie_soc_mt8192 = {
 	.power_up = mtk_pcie_power_up,
+	.phy_resets = {
+		.id[0] = "phy",
+		.num_resets = 1,
+	},
 };
 
 static const struct of_device_id mtk_pcie_of_match[] = {