[PATCH v2 09/11] PCI: dwc: pcie-kirin: allow using multiple reset GPIOs

[Mauro Carvalho Chehab]

On HiKey 970, the PCI hardware contains a bridge (PEX 8606), an Ethernet
controller (RTL8169), a M.2 connector and a mini 1X connector.

They work out of the box, but each of them requires its own reset line,
which should be initialized when the PCI hardware is reset.

So, add support for the DTS to contain multiple reset lines.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx>
---
 drivers/pci/controller/dwc/pcie-kirin.c | 148 +++++++++++++-----------
 1 file changed, 79 insertions(+), 69 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-kirin.c b/drivers/pci/controller/dwc/pcie-kirin.c
index 005fc4c2ad7f..4124c6ace349 100644
--- a/drivers/pci/controller/dwc/pcie-kirin.c
+++ b/drivers/pci/controller/dwc/pcie-kirin.c
@@ -139,6 +139,7 @@
 #define TIME_PHY_PD_MIN		10
 #define TIME_PHY_PD_MAX		11
 
+#define MAX_GPIO_RESETS		4
 struct kirin_pcie {
 	struct dw_pcie	*pci;
 	void __iomem	*apb_base;
@@ -151,8 +152,10 @@ struct kirin_pcie {
 	struct clk	*phy_ref_clk;
 	struct clk	*pcie_aclk;
 	struct clk	*pcie_aux_clk;
-	int		gpio_id_reset[4];
+	int		n_gpio_resets;
 	int		gpio_id_clkreq[3];
+	int		gpio_id_reset[MAX_GPIO_RESETS];
+	const char	*reset_names[MAX_GPIO_RESETS];
 	u32		eye_param[5];
 };
 
@@ -296,6 +299,24 @@ static void kirin970_pcie_set_eyeparam(struct kirin_pcie *kirin_pcie)
 static long kirin_common_pcie_get_resource(struct kirin_pcie *kirin_pcie,
 					   struct platform_device *pdev)
 {
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct regulator *reg;
+	char name[32];
+	int ret, i;
+
+	reg = devm_regulator_get_optional(dev, "pci");
+	if (IS_ERR_OR_NULL(reg)) {
+		if (PTR_ERR(reg) == -EPROBE_DEFER)
+		    return PTR_ERR(reg);
+	} else {
+		ret = regulator_enable(reg);
+		if (ret) {
+			dev_err(dev, "Failed to enable regulator\n");
+			return ret;
+		}
+	}
+
 	kirin_pcie->apb_base = devm_platform_ioremap_resource_byname(pdev,
 								     "apb");
 	if (IS_ERR(kirin_pcie->apb_base))
@@ -306,14 +327,47 @@ static long kirin_common_pcie_get_resource(struct kirin_pcie *kirin_pcie,
 	if (IS_ERR(kirin_pcie->phy_base))
 		return PTR_ERR(kirin_pcie->phy_base);
 
+	kirin_pcie->n_gpio_resets = of_gpio_named_count(np, "reset-gpios");
+	if (kirin_pcie->n_gpio_resets > MAX_GPIO_RESETS) {
+		dev_err(dev, "Too many GPIO resets!\n");
+		return -EINVAL;
+	}
+	for (i = 0; i < kirin_pcie->n_gpio_resets; i++) {
+		kirin_pcie->gpio_id_reset[i] = of_get_named_gpio(dev->of_node,
+							    "reset-gpios", i);
+		if (kirin_pcie->gpio_id_reset[i] < 0)
+			return kirin_pcie->gpio_id_reset[i];
+
+		sprintf(name, "pcie_perst_%d", i);
+		kirin_pcie->reset_names[i] = devm_kstrdup_const(dev, name,
+								GFP_KERNEL);
+		if (!kirin_pcie->reset_names[i])
+			return -ENOMEM;
+	}
+
 	return 0;
 }
 
+static int kirin_gpio_request(struct kirin_pcie *kirin_pcie,
+			      struct device *dev)
+{
+	int ret, i;
+
+	for (i = 0; i < kirin_pcie->n_gpio_resets; i++) {
+		ret = devm_gpio_request(dev, kirin_pcie->gpio_id_reset[i],
+					kirin_pcie->reset_names[i]);
+		if (ret)
+			return ret;
+	}
+
+
+	return ret;
+}
+
+
 static long kirin960_pcie_get_resource(struct kirin_pcie *kirin_pcie,
 				       struct platform_device *pdev)
 {
-	struct device *dev = &pdev->dev;
-
 	kirin_pcie->crgctrl =
 		syscon_regmap_lookup_by_compatible("hisilicon,hi3660-crgctrl");
 	if (IS_ERR(kirin_pcie->crgctrl))
@@ -324,16 +378,11 @@ static long kirin960_pcie_get_resource(struct kirin_pcie *kirin_pcie,
 	if (IS_ERR(kirin_pcie->sysctrl))
 		return PTR_ERR(kirin_pcie->sysctrl);
 
-	kirin_pcie->gpio_id_reset[0] = of_get_named_gpio(dev->of_node,
-						      "reset-gpios", 0);
-	if (kirin_pcie->gpio_id_reset[0] < 0)
-		return kirin_pcie->gpio_id_reset[0];
-
 	return 0;
 }
 
 static long kirin970_pcie_get_resource(struct kirin_pcie *kirin_pcie,
-				      struct platform_device *pdev)
+				       struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct regulator *reg;
@@ -353,40 +402,7 @@ static long kirin970_pcie_get_resource(struct kirin_pcie *kirin_pcie,
 
 	kirin970_pcie_get_eyeparam(kirin_pcie);
 
-	kirin_pcie->gpio_id_reset[0] = of_get_named_gpio(dev->of_node,
-						"switch,reset-gpios", 0);
-	if (kirin_pcie->gpio_id_reset[0] < 0)
-		return kirin_pcie->gpio_id_reset[0];
-
-	kirin_pcie->gpio_id_reset[1] = of_get_named_gpio(dev->of_node,
-						"eth,reset-gpios", 0);
-	if (kirin_pcie->gpio_id_reset[1] < 0)
-		return kirin_pcie->gpio_id_reset[1];
-
-	kirin_pcie->gpio_id_reset[2] = of_get_named_gpio(dev->of_node,
-						"m_2,reset-gpios", 0);
-	if (kirin_pcie->gpio_id_reset[2] < 0)
-		return kirin_pcie->gpio_id_reset[2];
-
-	kirin_pcie->gpio_id_reset[3] = of_get_named_gpio(dev->of_node,
-						"mini1,reset-gpios", 0);
-	if (kirin_pcie->gpio_id_reset[3] < 0)
-		return kirin_pcie->gpio_id_reset[3];
-
-	ret = devm_gpio_request(dev, kirin_pcie->gpio_id_reset[0],
-				    "pcie_switch_reset");
-	if (ret)
-		return ret;
-	ret = devm_gpio_request(dev, kirin_pcie->gpio_id_reset[1],
-				    "pcie_eth_reset");
-	if (ret)
-		return ret;
-	ret = devm_gpio_request(dev, kirin_pcie->gpio_id_reset[2],
-				    "pcie_m_2_reset");
-	if (ret)
-		return ret;
-	ret = devm_gpio_request(dev, kirin_pcie->gpio_id_reset[3],
-				    "pcie_mini1_reset");
+	ret = kirin_gpio_request(kirin_pcie, dev);
 	if (ret)
 		return ret;
 
@@ -846,7 +862,7 @@ static int kirin970_pcie_noc_power(struct kirin_pcie *kirin_pcie, bool enable)
 static int kirin970_pcie_power_on(struct kirin_pcie *kirin_pcie)
 {
 	struct device *dev = kirin_pcie->pci->dev;
-	int ret;
+	int ret, i;
 	u32 val;
 
 	/* Power supply for Host */
@@ -898,22 +914,11 @@ static int kirin970_pcie_power_on(struct kirin_pcie *kirin_pcie)
 
 	/* perst assert Endpoints */
 	usleep_range(21000, 23000);
-	ret = gpio_direction_output(kirin_pcie->gpio_id_reset[0], 1);
-	if (ret)
-		goto close_clk;
-
-	ret = gpio_direction_output(kirin_pcie->gpio_id_reset[1], 1);
-	if (ret)
-		goto close_clk;
-
-	ret = gpio_direction_output(kirin_pcie->gpio_id_reset[2], 1);
-	if (ret)
-		goto close_clk;
-
-	ret = gpio_direction_output(kirin_pcie->gpio_id_reset[3], 1);
-	if (ret)
-		goto close_clk;
-
+	for (i = 0; i < kirin_pcie->n_gpio_resets; i++) {
+		ret = gpio_direction_output(kirin_pcie->gpio_id_reset[i], 1);
+		if (ret)
+			return ret;
+	}
 	usleep_range(10000, 11000);
 
 	ret = is_pipe_clk_stable(kirin_pcie);
@@ -934,6 +939,7 @@ static int kirin970_pcie_power_on(struct kirin_pcie *kirin_pcie)
 
 static int kirin960_pcie_power_on(struct kirin_pcie *kirin_pcie)
 {
+	struct device *dev = kirin_pcie->pci->dev;
 	int ret;
 
 	/* Power supply for Host */
@@ -959,15 +965,19 @@ static int kirin960_pcie_power_on(struct kirin_pcie *kirin_pcie)
 		goto close_clk;
 
 	/* perst assert Endpoint */
-	if (!gpio_request(kirin_pcie->gpio_id_reset[0], "pcie_perst")) {
-		usleep_range(REF_2_PERST_MIN, REF_2_PERST_MAX);
-		ret = gpio_direction_output(kirin_pcie->gpio_id_reset[0], 1);
-		if (ret)
-			goto close_clk;
-		usleep_range(PERST_2_ACCESS_MIN, PERST_2_ACCESS_MAX);
-
-		return 0;
-	}
+	ret = kirin_gpio_request(kirin_pcie, dev);
+	if (ret)
+		goto close_clk;
+
+	usleep_range(REF_2_PERST_MIN, REF_2_PERST_MAX);
+
+	ret = gpio_direction_output(kirin_pcie->gpio_id_reset[0], 1);
+	if (ret)
+		goto close_clk;
+
+	usleep_range(PERST_2_ACCESS_MIN, PERST_2_ACCESS_MAX);
+
+	return 0;
 
 close_clk:
 	kirin_pcie_clk_ctrl(kirin_pcie, false);
-- 
2.29.2