[PATCH v7 1/4] PCI: imx6: Add code to support i.MX7D

From: Andrey Smirnov <hidden>
Date: 2017-03-21 13:43:04
Also in: linux-devicetree, linux-pci, lkml
Subsystem: multifunction devices (mfd), open firmware and flattened device tree bindings, pci native host bridge and endpoint drivers, pci subsystem, the rest · Maintainers: Lee Jones, Rob Herring, Krzysztof Kozlowski, Conor Dooley, Lorenzo Pieralisi, Krzysztof Wilczyński, Manivannan Sadhasivam, Bjorn Helgaas, Linus Torvalds

Add various bits of code needed to support i.MX7D variant of the IP.

Cc: yurovsky at gmail.com
Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Lee Jones <redacted>
Cc: Fabio Estevam <redacted>
Cc: Dong Aisheng <redacted>
Cc: linux-arm-kernel at lists.infradead.org
Cc: devicetree at vger.kernel.org
Cc: linux-kernel at vger.kernel.org
Acked-by: Lee Jones <redacted>
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Andrey Smirnov <redacted>
---
 .../devicetree/bindings/pci/fsl,imx6q-pcie.txt     |  13 ++-
 drivers/pci/dwc/pci-imx6.c                         | 120 ++++++++++++++++-----
 include/linux/mfd/syscon/imx7-iomuxc-gpr.h         |   4 +
 3 files changed, 111 insertions(+), 26 deletions(-)

diff --git a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
index 83aeb1f..11db2ab 100644
--- a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
+++ b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt

@@ -4,7 +4,11 @@ This PCIe host controller is based on the Synopsis Designware PCIe IP
 and thus inherits all the common properties defined in designware-pcie.txt.
 
 Required properties:
-- compatible: "fsl,imx6q-pcie", "fsl,imx6sx-pcie", "fsl,imx6qp-pcie"
+- compatible:
+	- "fsl,imx6q-pcie"
+	- "fsl,imx6sx-pcie",
+	- "fsl,imx6qp-pcie"
+	- "fsl,imx7d-pcie"
 - reg: base address and length of the PCIe controller
 - interrupts: A list of interrupt outputs of the controller. Must contain an
   entry for each entry in the interrupt-names property.

@@ -34,6 +38,13 @@ Additional required properties for imx6sx-pcie:
 - clock names: Must include the following additional entries:
 	- "pcie_inbound_axi"
 
+Additional required properties for imx7d-pcie:
+- power-domains: Must be set to a phandle pointing to PCIE_PHY power domain
+- resets: Must contain phandles to PCIE related reset lines exposed by SRC IP block
+- reset-names: Must contain the following entires:
+  	       - "pciephy"
+	       - "apps"
+
 Example:
 
 	pcie at 0x01000000 {

diff --git a/drivers/pci/dwc/pci-imx6.c b/drivers/pci/dwc/pci-imx6.c
index 801e46c..e0c36d6 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 @@ static void imx6_pcie_deassert_core_reset(struct imx6_pcie *imx6_pcie)
 
 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)

@@ -653,13 +704,31 @@ 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 contol\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 contol\n");
+			return PTR_ERR(imx6_pcie->apps_reset);
+		}
+		break;
+	default:
+		break;
 	}
 
 	/* Grab GPR config register range */

@@ -718,6 +787,7 @@ 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,  },
 	{},
 };

diff --git a/include/linux/mfd/syscon/imx7-iomuxc-gpr.h b/include/linux/mfd/syscon/imx7-iomuxc-gpr.h
index 4585d61..abbd524 100644
--- a/include/linux/mfd/syscon/imx7-iomuxc-gpr.h
+++ b/include/linux/mfd/syscon/imx7-iomuxc-gpr.h

@@ -44,4 +44,8 @@
 
 #define IMX7D_GPR5_CSI_MUX_CONTROL_MIPI		(0x1 << 4)
 
+#define IMX7D_GPR12_PCIE_PHY_REFCLK_SEL		BIT(5)
+
+#define IMX7D_GPR22_PCIE_PHY_PLL_LOCKED		BIT(31)
+
 #endif /* __LINUX_IMX7_IOMUXC_GPR_H */

-- 
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