Merge branch 'pci/host-imx6' into next

* pci/host-imx6:
  PCI: imx6: Fix spelling mistake: "contol" -> "control"
  PCI: imx6: Do not switch speed if Gen2 is disabled
  PCI: imx6: Do not wait for speed change on i.MX7
  PCI: imx6: Allow probe deferral by reset GPIO
  PCI: imx6: Add code to support i.MX7D

1 files changed, 144 insertions, 54 deletions

diff --git a/drivers/pci/dwc/pci-imx6.c b/drivers/pci/dwc/pci-imx6.c
index 801e46cd266d..129717ae5022 100644
--- a/drivers/pci/dwc/pci-imx6.c
+++ b/drivers/pci/dwc/pci-imx6.c
@@ -17,6 +17,7 @@
 #include <linux/kernel.h>
 #include <linux/mfd/syscon.h>
 #include <linux/mfd/syscon/imx6q-iomuxc-gpr.h>
+#include <linux/mfd/syscon/imx7-iomuxc-gpr.h>
 #include <linux/module.h>
 #include <linux/of_gpio.h>
 #include <linux/of_device.h>
@@ -27,6 +28,7 @@
 #include <linux/signal.h>
 #include <linux/types.h>
 #include <linux/interrupt.h>
+#include <linux/reset.h>
 
 #include "pcie-designware.h"
 
@@ -36,6 +38,7 @@ enum imx6_pcie_variants {
 	IMX6Q,
 	IMX6SX,
 	IMX6QP,
+	IMX7D,
 };
 
 struct imx6_pcie {
@@ -47,6 +50,8 @@ struct imx6_pcie {
 	struct clk		*pcie_inbound_axi;
 	struct clk		*pcie;
 	struct regmap		*iomuxc_gpr;
+	struct reset_control	*pciephy_reset;
+	struct reset_control	*apps_reset;
 	enum imx6_pcie_variants variant;
 	u32			tx_deemph_gen1;
 	u32			tx_deemph_gen2_3p5db;
@@ -56,6 +61,11 @@ struct imx6_pcie {
 	int			link_gen;
 };
 
+/* Parameters for the waiting for PCIe PHY PLL to lock on i.MX7 */
+#define PHY_PLL_LOCK_WAIT_MAX_RETRIES	2000
+#define PHY_PLL_LOCK_WAIT_USLEEP_MIN	50
+#define PHY_PLL_LOCK_WAIT_USLEEP_MAX	200
+
 /* PCIe Root Complex registers (memory-mapped) */
 #define PCIE_RC_LCR				0x7c
 #define PCIE_RC_LCR_MAX_LINK_SPEEDS_GEN1	0x1
@@ -248,6 +258,10 @@ static int imx6q_pcie_abort_handler(unsigned long addr,
 static void imx6_pcie_assert_core_reset(struct imx6_pcie *imx6_pcie)
 {
 	switch (imx6_pcie->variant) {
+	case IMX7D:
+		reset_control_assert(imx6_pcie->pciephy_reset);
+		reset_control_assert(imx6_pcie->apps_reset);
+		break;
 	case IMX6SX:
 		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
 				   IMX6SX_GPR12_PCIE_TEST_POWERDOWN,
@@ -303,11 +317,32 @@ static int imx6_pcie_enable_ref_clk(struct imx6_pcie *imx6_pcie)
 		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
 				   IMX6Q_GPR1_PCIE_REF_CLK_EN, 1 << 16);
 		break;
+	case IMX7D:
+		break;
 	}
 
 	return ret;
 }
 
+static void imx7d_pcie_wait_for_phy_pll_lock(struct imx6_pcie *imx6_pcie)
+{
+	u32 val;
+	unsigned int retries;
+	struct device *dev = imx6_pcie->pci->dev;
+
+	for (retries = 0; retries < PHY_PLL_LOCK_WAIT_MAX_RETRIES; retries++) {
+		regmap_read(imx6_pcie->iomuxc_gpr, IOMUXC_GPR22, &val);
+
+		if (val & IMX7D_GPR22_PCIE_PHY_PLL_LOCKED)
+			return;
+
+		usleep_range(PHY_PLL_LOCK_WAIT_USLEEP_MIN,
+			     PHY_PLL_LOCK_WAIT_USLEEP_MAX);
+	}
+
+	dev_err(dev, "PCIe PLL lock timeout\n");
+}
+
 static void imx6_pcie_deassert_core_reset(struct imx6_pcie *imx6_pcie)
 {
 	struct dw_pcie *pci = imx6_pcie->pci;
@@ -351,6 +386,10 @@ static void imx6_pcie_deassert_core_reset(struct imx6_pcie *imx6_pcie)
 	}
 
 	switch (imx6_pcie->variant) {
+	case IMX7D:
+		reset_control_deassert(imx6_pcie->pciephy_reset);
+		imx7d_pcie_wait_for_phy_pll_lock(imx6_pcie);
+		break;
 	case IMX6SX:
 		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR5,
 				   IMX6SX_GPR5_PCIE_BTNRST_RESET, 0);
@@ -377,35 +416,44 @@ err_pcie_bus:
 
 static void imx6_pcie_init_phy(struct imx6_pcie *imx6_pcie)
 {
-	if (imx6_pcie->variant == IMX6SX)
+	switch (imx6_pcie->variant) {
+	case IMX7D:
+		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
+				   IMX7D_GPR12_PCIE_PHY_REFCLK_SEL, 0);
+		break;
+	case IMX6SX:
 		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
 				   IMX6SX_GPR12_PCIE_RX_EQ_MASK,
 				   IMX6SX_GPR12_PCIE_RX_EQ_2);
+		/* FALLTHROUGH */
+	default:
+		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
+				   IMX6Q_GPR12_PCIE_CTL_2, 0 << 10);
 
-	regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
-			IMX6Q_GPR12_PCIE_CTL_2, 0 << 10);
+		/* configure constant input signal to the pcie ctrl and phy */
+		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
+				   IMX6Q_GPR12_LOS_LEVEL, 9 << 4);
+
+		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
+				   IMX6Q_GPR8_TX_DEEMPH_GEN1,
+				   imx6_pcie->tx_deemph_gen1 << 0);
+		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
+				   IMX6Q_GPR8_TX_DEEMPH_GEN2_3P5DB,
+				   imx6_pcie->tx_deemph_gen2_3p5db << 6);
+		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
+				   IMX6Q_GPR8_TX_DEEMPH_GEN2_6DB,
+				   imx6_pcie->tx_deemph_gen2_6db << 12);
+		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
+				   IMX6Q_GPR8_TX_SWING_FULL,
+				   imx6_pcie->tx_swing_full << 18);
+		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
+				   IMX6Q_GPR8_TX_SWING_LOW,
+				   imx6_pcie->tx_swing_low << 25);
+		break;
+	}
 
-	/* configure constant input signal to the pcie ctrl and phy */
 	regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
 			IMX6Q_GPR12_DEVICE_TYPE, PCI_EXP_TYPE_ROOT_PORT << 12);
-	regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
-			IMX6Q_GPR12_LOS_LEVEL, 9 << 4);
-
-	regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
-			   IMX6Q_GPR8_TX_DEEMPH_GEN1,
-			   imx6_pcie->tx_deemph_gen1 << 0);
-	regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
-			   IMX6Q_GPR8_TX_DEEMPH_GEN2_3P5DB,
-			   imx6_pcie->tx_deemph_gen2_3p5db << 6);
-	regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
-			   IMX6Q_GPR8_TX_DEEMPH_GEN2_6DB,
-			   imx6_pcie->tx_deemph_gen2_6db << 12);
-	regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
-			   IMX6Q_GPR8_TX_SWING_FULL,
-			   imx6_pcie->tx_swing_full << 18);
-	regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
-			   IMX6Q_GPR8_TX_SWING_LOW,
-			   imx6_pcie->tx_swing_low << 25);
 }
 
 static int imx6_pcie_wait_for_link(struct imx6_pcie *imx6_pcie)
@@ -469,8 +517,11 @@ static int imx6_pcie_establish_link(struct imx6_pcie *imx6_pcie)
 	dw_pcie_writel_dbi(pci, PCIE_RC_LCR, tmp);
 
 	/* Start LTSSM. */
-	regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
-			IMX6Q_GPR12_PCIE_CTL_2, 1 << 10);
+	if (imx6_pcie->variant == IMX7D)
+		reset_control_deassert(imx6_pcie->apps_reset);
+	else
+		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
+				   IMX6Q_GPR12_PCIE_CTL_2, 1 << 10);
 
 	ret = imx6_pcie_wait_for_link(imx6_pcie);
 	if (ret)
@@ -482,29 +533,40 @@ static int imx6_pcie_establish_link(struct imx6_pcie *imx6_pcie)
 		tmp &= ~PCIE_RC_LCR_MAX_LINK_SPEEDS_MASK;
 		tmp |= PCIE_RC_LCR_MAX_LINK_SPEEDS_GEN2;
 		dw_pcie_writel_dbi(pci, PCIE_RC_LCR, tmp);
-	} else {
-		dev_info(dev, "Link: Gen2 disabled\n");
-	}
-
-	/*
-	 * Start Directed Speed Change so the best possible speed both link
-	 * partners support can be negotiated.
-	 */
-	tmp = dw_pcie_readl_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL);
-	tmp |= PORT_LOGIC_SPEED_CHANGE;
-	dw_pcie_writel_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL, tmp);
 
-	ret = imx6_pcie_wait_for_speed_change(imx6_pcie);
-	if (ret) {
-		dev_err(dev, "Failed to bring link up!\n");
-		goto err_reset_phy;
-	}
+		/*
+		 * Start Directed Speed Change so the best possible
+		 * speed both link partners support can be negotiated.
+		 */
+		tmp = dw_pcie_readl_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL);
+		tmp |= PORT_LOGIC_SPEED_CHANGE;
+		dw_pcie_writel_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL, tmp);
+
+		if (imx6_pcie->variant != IMX7D) {
+			/*
+			 * On i.MX7, DIRECT_SPEED_CHANGE behaves differently
+			 * from i.MX6 family when no link speed transition
+			 * occurs and we go Gen1 -> yep, Gen1. The difference
+			 * is that, in such case, it will not be cleared by HW
+			 * which will cause the following code to report false
+			 * failure.
+			 */
+
+			ret = imx6_pcie_wait_for_speed_change(imx6_pcie);
+			if (ret) {
+				dev_err(dev, "Failed to bring link up!\n");
+				goto err_reset_phy;
+			}
+		}
 
-	/* Make sure link training is finished as well! */
-	ret = imx6_pcie_wait_for_link(imx6_pcie);
-	if (ret) {
-		dev_err(dev, "Failed to bring link up!\n");
-		goto err_reset_phy;
+		/* Make sure link training is finished as well! */
+		ret = imx6_pcie_wait_for_link(imx6_pcie);
+		if (ret) {
+			dev_err(dev, "Failed to bring link up!\n");
+			goto err_reset_phy;
+		}
+	} else {
+		dev_info(dev, "Link: Gen2 disabled\n");
 	}
 
 	tmp = dw_pcie_readl_dbi(pci, PCIE_RC_LCSR);
@@ -544,8 +606,8 @@ static struct dw_pcie_host_ops imx6_pcie_host_ops = {
 	.host_init = imx6_pcie_host_init,
 };
 
-static int __init imx6_add_pcie_port(struct imx6_pcie *imx6_pcie,
-				     struct platform_device *pdev)
+static int imx6_add_pcie_port(struct imx6_pcie *imx6_pcie,
+			      struct platform_device *pdev)
 {
 	struct dw_pcie *pci = imx6_pcie->pci;
 	struct pcie_port *pp = &pci->pp;
@@ -585,7 +647,7 @@ static const struct dw_pcie_ops dw_pcie_ops = {
 	.link_up = imx6_pcie_link_up,
 };
 
-static int __init imx6_pcie_probe(struct platform_device *pdev)
+static int imx6_pcie_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct dw_pcie *pci;
@@ -609,10 +671,6 @@ static int __init imx6_pcie_probe(struct platform_device *pdev)
 	imx6_pcie->variant =
 		(enum imx6_pcie_variants)of_device_get_match_data(dev);
 
-	/* Added for PCI abort handling */
-	hook_fault_code(16 + 6, imx6q_pcie_abort_handler, SIGBUS, 0,
-		"imprecise external abort");
-
 	dbi_base = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	pci->dbi_base = devm_ioremap_resource(dev, dbi_base);
 	if (IS_ERR(pci->dbi_base))
@@ -632,6 +690,8 @@ static int __init imx6_pcie_probe(struct platform_device *pdev)
 			dev_err(dev, "unable to get reset gpio\n");
 			return ret;
 		}
+	} else if (imx6_pcie->reset_gpio == -EPROBE_DEFER) {
+		return imx6_pcie->reset_gpio;
 	}
 
 	/* Fetch clocks */
@@ -653,13 +713,31 @@ static int __init imx6_pcie_probe(struct platform_device *pdev)
 		return PTR_ERR(imx6_pcie->pcie);
 	}
 
-	if (imx6_pcie->variant == IMX6SX) {
+	switch (imx6_pcie->variant) {
+	case IMX6SX:
 		imx6_pcie->pcie_inbound_axi = devm_clk_get(dev,
 							   "pcie_inbound_axi");
 		if (IS_ERR(imx6_pcie->pcie_inbound_axi)) {
 			dev_err(dev, "pcie_inbound_axi clock missing or invalid\n");
 			return PTR_ERR(imx6_pcie->pcie_inbound_axi);
 		}
+		break;
+	case IMX7D:
+		imx6_pcie->pciephy_reset = devm_reset_control_get(dev,
+								  "pciephy");
+		if (IS_ERR(imx6_pcie->pciephy_reset)) {
+			dev_err(dev, "Failed to get PCIEPHY reset control\n");
+			return PTR_ERR(imx6_pcie->pciephy_reset);
+		}
+
+		imx6_pcie->apps_reset = devm_reset_control_get(dev, "apps");
+		if (IS_ERR(imx6_pcie->apps_reset)) {
+			dev_err(dev, "Failed to get PCIE APPS reset control\n");
+			return PTR_ERR(imx6_pcie->apps_reset);
+		}
+		break;
+	default:
+		break;
 	}
 
 	/* Grab GPR config register range */
@@ -718,6 +796,7 @@ static const struct of_device_id imx6_pcie_of_match[] = {
 	{ .compatible = "fsl,imx6q-pcie",  .data = (void *)IMX6Q,  },
 	{ .compatible = "fsl,imx6sx-pcie", .data = (void *)IMX6SX, },
 	{ .compatible = "fsl,imx6qp-pcie", .data = (void *)IMX6QP, },
+	{ .compatible = "fsl,imx7d-pcie",  .data = (void *)IMX7D,  },
 	{},
 };
 
@@ -726,11 +805,22 @@ static struct platform_driver imx6_pcie_driver = {
 		.name	= "imx6q-pcie",
 		.of_match_table = imx6_pcie_of_match,
 	},
+	.probe    = imx6_pcie_probe,
 	.shutdown = imx6_pcie_shutdown,
 };
 
 static int __init imx6_pcie_init(void)
 {
-	return platform_driver_probe(&imx6_pcie_driver, imx6_pcie_probe);
+	/*
+	 * Since probe() can be deferred we need to make sure that
+	 * hook_fault_code is not called after __init memory is freed
+	 * by kernel and since imx6q_pcie_abort_handler() is a no-op,
+	 * we can install the handler here without risking it
+	 * accessing some uninitialized driver state.
+	 */
+	hook_fault_code(16 + 6, imx6q_pcie_abort_handler, SIGBUS, 0,
+			"imprecise external abort");
+
+	return platform_driver_register(&imx6_pcie_driver);
 }
 device_initcall(imx6_pcie_init);