1 files changed, 174 insertions, 53 deletions

diff --git a/drivers/pci/host/pci-imx6.c b/drivers/pci/host/pci-imx6.c
index eb5a2755a164..b741a36a67f3 100644
--- a/drivers/pci/host/pci-imx6.c
+++ b/drivers/pci/host/pci-imx6.c
@@ -19,6 +19,7 @@
 #include <linux/mfd/syscon/imx6q-iomuxc-gpr.h>
 #include <linux/module.h>
 #include <linux/of_gpio.h>
+#include <linux/of_device.h>
 #include <linux/pci.h>
 #include <linux/platform_device.h>
 #include <linux/regmap.h>
@@ -31,19 +32,29 @@
 
 #define to_imx6_pcie(x)	container_of(x, struct imx6_pcie, pp)
 
+enum imx6_pcie_variants {
+	IMX6Q,
+	IMX6SX,
+	IMX6QP,
+};
+
 struct imx6_pcie {
-	struct gpio_desc	*reset_gpio;
+	int			reset_gpio;
+	bool			gpio_active_high;
 	struct clk		*pcie_bus;
 	struct clk		*pcie_phy;
+	struct clk		*pcie_inbound_axi;
 	struct clk		*pcie;
 	struct pcie_port	pp;
 	struct regmap		*iomuxc_gpr;
+	enum imx6_pcie_variants variant;
 	void __iomem		*mem_base;
 	u32			tx_deemph_gen1;
 	u32			tx_deemph_gen2_3p5db;
 	u32			tx_deemph_gen2_6db;
 	u32			tx_swing_full;
 	u32			tx_swing_low;
+	int			link_gen;
 };
 
 /* PCIe Root Complex registers (memory-mapped) */
@@ -236,37 +247,93 @@ static int imx6_pcie_assert_core_reset(struct pcie_port *pp)
 	struct imx6_pcie *imx6_pcie = to_imx6_pcie(pp);
 	u32 val, gpr1, gpr12;
 
-	/*
-	 * If the bootloader already enabled the link we need some special
-	 * handling to get the core back into a state where it is safe to
-	 * touch it for configuration.  As there is no dedicated reset signal
-	 * wired up for MX6QDL, we need to manually force LTSSM into "detect"
-	 * state before completely disabling LTSSM, which is a prerequisite
-	 * for core configuration.
-	 *
-	 * If both LTSSM_ENABLE and REF_SSP_ENABLE are active we have a strong
-	 * indication that the bootloader activated the link.
-	 */
-	regmap_read(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, &gpr1);
-	regmap_read(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, &gpr12);
+	switch (imx6_pcie->variant) {
+	case IMX6SX:
+		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
+				   IMX6SX_GPR12_PCIE_TEST_POWERDOWN,
+				   IMX6SX_GPR12_PCIE_TEST_POWERDOWN);
+		/* Force PCIe PHY reset */
+		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR5,
+				   IMX6SX_GPR5_PCIE_BTNRST_RESET,
+				   IMX6SX_GPR5_PCIE_BTNRST_RESET);
+		break;
+	case IMX6QP:
+		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
+				   IMX6Q_GPR1_PCIE_SW_RST,
+				   IMX6Q_GPR1_PCIE_SW_RST);
+		break;
+	case IMX6Q:
+		/*
+		 * If the bootloader already enabled the link we need some
+		 * special handling to get the core back into a state where
+		 * it is safe to touch it for configuration.  As there is
+		 * no dedicated reset signal wired up for MX6QDL, we need
+		 * to manually force LTSSM into "detect" state before
+		 * completely disabling LTSSM, which is a prerequisite for
+		 * core configuration.
+		 *
+		 * If both LTSSM_ENABLE and REF_SSP_ENABLE are active we
+		 * have a strong indication that the bootloader activated
+		 * the link.
+		 */
+		regmap_read(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, &gpr1);
+		regmap_read(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, &gpr12);
+
+		if ((gpr1 & IMX6Q_GPR1_PCIE_REF_CLK_EN) &&
+		    (gpr12 & IMX6Q_GPR12_PCIE_CTL_2)) {
+			val = readl(pp->dbi_base + PCIE_PL_PFLR);
+			val &= ~PCIE_PL_PFLR_LINK_STATE_MASK;
+			val |= PCIE_PL_PFLR_FORCE_LINK;
+			writel(val, pp->dbi_base + PCIE_PL_PFLR);
+
+			regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
+					   IMX6Q_GPR12_PCIE_CTL_2, 0 << 10);
+		}
+
+		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
+				   IMX6Q_GPR1_PCIE_TEST_PD, 1 << 18);
+		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
+				   IMX6Q_GPR1_PCIE_REF_CLK_EN, 0 << 16);
+		break;
+	}
+
+	return 0;
+}
 
-	if ((gpr1 & IMX6Q_GPR1_PCIE_REF_CLK_EN) &&
-	    (gpr12 & IMX6Q_GPR12_PCIE_CTL_2)) {
-		val = readl(pp->dbi_base + PCIE_PL_PFLR);
-		val &= ~PCIE_PL_PFLR_LINK_STATE_MASK;
-		val |= PCIE_PL_PFLR_FORCE_LINK;
-		writel(val, pp->dbi_base + PCIE_PL_PFLR);
+static int imx6_pcie_enable_ref_clk(struct imx6_pcie *imx6_pcie)
+{
+	struct pcie_port *pp = &imx6_pcie->pp;
+	int ret = 0;
+
+	switch (imx6_pcie->variant) {
+	case IMX6SX:
+		ret = clk_prepare_enable(imx6_pcie->pcie_inbound_axi);
+		if (ret) {
+			dev_err(pp->dev, "unable to enable pcie_axi clock\n");
+			break;
+		}
 
 		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
-				IMX6Q_GPR12_PCIE_CTL_2, 0 << 10);
+				   IMX6SX_GPR12_PCIE_TEST_POWERDOWN, 0);
+		break;
+	case IMX6QP: 		/* FALLTHROUGH */
+	case IMX6Q:
+		/* power up core phy and enable ref clock */
+		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
+				   IMX6Q_GPR1_PCIE_TEST_PD, 0 << 18);
+		/*
+		 * the async reset input need ref clock to sync internally,
+		 * when the ref clock comes after reset, internal synced
+		 * reset time is too short, cannot meet the requirement.
+		 * add one ~10us delay here.
+		 */
+		udelay(10);
+		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
+				   IMX6Q_GPR1_PCIE_REF_CLK_EN, 1 << 16);
+		break;
 	}
 
-	regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
-			IMX6Q_GPR1_PCIE_TEST_PD, 1 << 18);
-	regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
-			IMX6Q_GPR1_PCIE_REF_CLK_EN, 0 << 16);
-
-	return 0;
+	return ret;
 }
 
 static int imx6_pcie_deassert_core_reset(struct pcie_port *pp)
@@ -292,43 +359,60 @@ static int imx6_pcie_deassert_core_reset(struct pcie_port *pp)
 		goto err_pcie;
 	}
 
-	/* power up core phy and enable ref clock */
-	regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
-			IMX6Q_GPR1_PCIE_TEST_PD, 0 << 18);
-	/*
-	 * the async reset input need ref clock to sync internally,
-	 * when the ref clock comes after reset, internal synced
-	 * reset time is too short, cannot meet the requirement.
-	 * add one ~10us delay here.
-	 */
-	udelay(10);
-	regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
-			IMX6Q_GPR1_PCIE_REF_CLK_EN, 1 << 16);
+	ret = imx6_pcie_enable_ref_clk(imx6_pcie);
+	if (ret) {
+		dev_err(pp->dev, "unable to enable pcie ref clock\n");
+		goto err_ref_clk;
+	}
 
 	/* allow the clocks to stabilize */
 	usleep_range(200, 500);
 
 	/* Some boards don't have PCIe reset GPIO. */
-	if (imx6_pcie->reset_gpio) {
-		gpiod_set_value_cansleep(imx6_pcie->reset_gpio, 0);
+	if (gpio_is_valid(imx6_pcie->reset_gpio)) {
+		gpio_set_value_cansleep(imx6_pcie->reset_gpio,
+					imx6_pcie->gpio_active_high);
 		msleep(100);
-		gpiod_set_value_cansleep(imx6_pcie->reset_gpio, 1);
+		gpio_set_value_cansleep(imx6_pcie->reset_gpio,
+					!imx6_pcie->gpio_active_high);
 	}
+
+	switch (imx6_pcie->variant) {
+	case IMX6SX:
+		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR5,
+				   IMX6SX_GPR5_PCIE_BTNRST_RESET, 0);
+		break;
+	case IMX6QP:
+		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
+				   IMX6Q_GPR1_PCIE_SW_RST, 0);
+
+		usleep_range(200, 500);
+		break;
+	case IMX6Q:		/* Nothing to do */
+		break;
+	}
+
 	return 0;
 
+err_ref_clk:
+	clk_disable_unprepare(imx6_pcie->pcie);
 err_pcie:
 	clk_disable_unprepare(imx6_pcie->pcie_bus);
 err_pcie_bus:
 	clk_disable_unprepare(imx6_pcie->pcie_phy);
 err_pcie_phy:
 	return ret;
-
 }
 
 static void imx6_pcie_init_phy(struct pcie_port *pp)
 {
 	struct imx6_pcie *imx6_pcie = to_imx6_pcie(pp);
 
+	if (imx6_pcie->variant == IMX6SX)
+		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
+				   IMX6SX_GPR12_PCIE_RX_EQ_MASK,
+				   IMX6SX_GPR12_PCIE_RX_EQ_2);
+
 	regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
 			IMX6Q_GPR12_PCIE_CTL_2, 0 << 10);
 
@@ -417,11 +501,15 @@ static int imx6_pcie_establish_link(struct pcie_port *pp)
 		goto err_reset_phy;
 	}
 
-	/* Allow Gen2 mode after the link is up. */
-	tmp = readl(pp->dbi_base + PCIE_RC_LCR);
-	tmp &= ~PCIE_RC_LCR_MAX_LINK_SPEEDS_MASK;
-	tmp |= PCIE_RC_LCR_MAX_LINK_SPEEDS_GEN2;
-	writel(tmp, pp->dbi_base + PCIE_RC_LCR);
+	if (imx6_pcie->link_gen == 2) {
+		/* Allow Gen2 mode after the link is up. */
+		tmp = readl(pp->dbi_base + PCIE_RC_LCR);
+		tmp &= ~PCIE_RC_LCR_MAX_LINK_SPEEDS_MASK;
+		tmp |= PCIE_RC_LCR_MAX_LINK_SPEEDS_GEN2;
+		writel(tmp, pp->dbi_base + PCIE_RC_LCR);
+	} else {
+		dev_info(pp->dev, "Link: Gen2 disabled\n");
+	}
 
 	/*
 	 * Start Directed Speed Change so the best possible speed both link
@@ -445,8 +533,7 @@ static int imx6_pcie_establish_link(struct pcie_port *pp)
 	}
 
 	tmp = readl(pp->dbi_base + PCIE_RC_LCSR);
-	dev_dbg(pp->dev, "Link up, Gen=%i\n", (tmp >> 16) & 0xf);
-
+	dev_info(pp->dev, "Link up, Gen%i\n", (tmp >> 16) & 0xf);
 	return 0;
 
 err_reset_phy:
@@ -523,6 +610,7 @@ static int __init imx6_pcie_probe(struct platform_device *pdev)
 {
 	struct imx6_pcie *imx6_pcie;
 	struct pcie_port *pp;
+	struct device_node *np = pdev->dev.of_node;
 	struct resource *dbi_base;
 	struct device_node *node = pdev->dev.of_node;
 	int ret;
@@ -534,6 +622,9 @@ static int __init imx6_pcie_probe(struct platform_device *pdev)
 	pp = &imx6_pcie->pp;
 	pp->dev = &pdev->dev;
 
+	imx6_pcie->variant =
+		(enum imx6_pcie_variants)of_device_get_match_data(&pdev->dev);
+
 	/* Added for PCI abort handling */
 	hook_fault_code(16 + 6, imx6q_pcie_abort_handler, SIGBUS, 0,
 		"imprecise external abort");
@@ -544,8 +635,20 @@ static int __init imx6_pcie_probe(struct platform_device *pdev)
 		return PTR_ERR(pp->dbi_base);
 
 	/* Fetch GPIOs */
-	imx6_pcie->reset_gpio = devm_gpiod_get_optional(&pdev->dev, "reset",
-							GPIOD_OUT_LOW);
+	imx6_pcie->reset_gpio = of_get_named_gpio(np, "reset-gpio", 0);
+	imx6_pcie->gpio_active_high = of_property_read_bool(np,
+						"reset-gpio-active-high");
+	if (gpio_is_valid(imx6_pcie->reset_gpio)) {
+		ret = devm_gpio_request_one(&pdev->dev, imx6_pcie->reset_gpio,
+				imx6_pcie->gpio_active_high ?
+					GPIOF_OUT_INIT_HIGH :
+					GPIOF_OUT_INIT_LOW,
+				"PCIe reset");
+		if (ret) {
+			dev_err(&pdev->dev, "unable to get reset gpio\n");
+			return ret;
+		}
+	}
 
 	/* Fetch clocks */
 	imx6_pcie->pcie_phy = devm_clk_get(&pdev->dev, "pcie_phy");
@@ -569,6 +672,16 @@ static int __init imx6_pcie_probe(struct platform_device *pdev)
 		return PTR_ERR(imx6_pcie->pcie);
 	}
 
+	if (imx6_pcie->variant == IMX6SX) {
+		imx6_pcie->pcie_inbound_axi = devm_clk_get(&pdev->dev,
+							   "pcie_inbound_axi");
+		if (IS_ERR(imx6_pcie->pcie_inbound_axi)) {
+			dev_err(&pdev->dev,
+				"pcie_incbound_axi clock missing or invalid\n");
+			return PTR_ERR(imx6_pcie->pcie_inbound_axi);
+		}
+	}
+
 	/* Grab GPR config register range */
 	imx6_pcie->iomuxc_gpr =
 		 syscon_regmap_lookup_by_compatible("fsl,imx6q-iomuxc-gpr");
@@ -598,6 +711,12 @@ static int __init imx6_pcie_probe(struct platform_device *pdev)
 				 &imx6_pcie->tx_swing_low))
 		imx6_pcie->tx_swing_low = 127;
 
+	/* Limit link speed */
+	ret = of_property_read_u32(pp->dev->of_node, "fsl,max-link-speed",
+				   &imx6_pcie->link_gen);
+	if (ret)
+		imx6_pcie->link_gen = 1;
+
 	ret = imx6_add_pcie_port(pp, pdev);
 	if (ret < 0)
 		return ret;
@@ -615,7 +734,9 @@ static void imx6_pcie_shutdown(struct platform_device *pdev)
 }
 
 static const struct of_device_id imx6_pcie_of_match[] = {
-	{ .compatible = "fsl,imx6q-pcie", },
+	{ .compatible = "fsl,imx6q-pcie",  .data = (void *)IMX6Q,  },
+	{ .compatible = "fsl,imx6sx-pcie", .data = (void *)IMX6SX, },
+	{ .compatible = "fsl,imx6qp-pcie", .data = (void *)IMX6QP, },
 	{},
 };
 MODULE_DEVICE_TABLE(of, imx6_pcie_of_match);