[RESEND PATCH v5 0/4] i.MX7 PCI support

[RESEND PATCH v5 0/4] i.MX7 PCI support

[Andrey Smirnov]

[ RESEND becasue I messed up CC list of patches 2,3 of the original
  submission as well as not adding Reviewed-by to patch 1 and droping
  it from patch 4 ]

Hello, everyone:

This is a fifth iteration of the code that adds PCI-subsystem bits
necessary for enabling PCI support on i.MX7.

Rob, Bjorn, power domain and reset bindings remained the same, please
let me know if you still think that PHY aspect of the driver needs to
be moved into a separate abstraction.

Changes since v4 (can be found at [version4]):

	- Dropped typo-fix patch (originally patch #1 of the
          series). Bjorn, I am assuming that patch from v4 survived
          and stayed in your tree, let me know if that is not true.

	- Added patch with workaround to address speed change false
          failures (I kept it as a separate patch to better document
          exchange with NXP/Freescale that lead to that patch)

	- Added patch to avoid speed change on links configured Gen1
          only (Let me know if that is a terrible idea)

	- Addressed section mismatch problem by moving call to
          hook_fault_code to happend before driver registration.

Changes since v3 (can be found at [version3]):
	- Move all of the reset_control_assert's into imx6_pcie_assert_core_reset
	- Documented required reset and power domain DT bindings

Changes since v2 (can be found at [version2]):

	- Collected Reviewed-by for patch #2 from Lucas
	- Reset logic implementation moved out into a reset controller
          driver (see [reset1])
	- Removed unused leftover code

Changes since v1 (can be found at [version1]):

	- All GPC related code moved into a separate driver (see [gpc1])
	- Removed GPIO probe deferral logging
	- Fixed section mismatch warning
	- Minor reformatting of fsl,imx6q-pcie.txt(as per Rob
          Herring's request)

[version4] https://lkml.org/lkml/2017/2/7/478
[version3] https://lkml.org/lkml/2017/2/6/565
[version2] https://lkml.org/lkml/2017/2/1/510
[version1] https://lkml.org/lkml/2017/1/19/488
[gpc1] https://lkml.org/lkml/2017/2/6/551
[reset1] https://lkml.org/lkml/2017/2/6/554

Andrey Smirnov (4):
  PCI: imx6: Add code to support i.MX7D
  PCI: imx6: Do not wait for speed change on i.MX7
  PCI: imx6: Do not switch speed if Gen2 is disabled
  PCI: imx6: Allow probe deferal by reset GPIO

 .../devicetree/bindings/pci/fsl,imx6q-pcie.txt     |  13 +-
 drivers/pci/host/pci-imx6.c                        | 199 +++++++++++++++------
 include/linux/mfd/syscon/imx7-iomuxc-gpr.h         |   4 +
 3 files changed, 161 insertions(+), 55 deletions(-)

-- 
2.9.3

[RESEND PATCH v5 1/4] PCI: imx6: Add code to support i.MX7D

[Andrey Smirnov]

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

Cc: yurovsky@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 <lee.jones@linaro.org>
Cc: Fabio Estevam <fabio.estevam@nxp.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: devicetree@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
---
 .../devicetree/bindings/pci/fsl,imx6q-pcie.txt     |  13 ++-
 drivers/pci/host/pci-imx6.c                        | 121 ++++++++++++++++-----
 include/linux/mfd/syscon/imx7-iomuxc-gpr.h         |   4 +
 3 files changed, 112 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@0x01000000 {
diff --git a/drivers/pci/host/pci-imx6.c b/drivers/pci/host/pci-imx6.c
index 50a1291..2f3f375 100644
--- a/drivers/pci/host/pci-imx6.c
+++ b/drivers/pci/host/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
@@ -251,6 +261,10 @@ static void imx6_pcie_assert_core_reset(struct imx6_pcie *imx6_pcie)
 	u32 val, gpr1, gpr12;
 
 	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,
@@ -333,11 +347,33 @@ 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 pcie_port *pp = &imx6_pcie->pp;
+	struct device *dev = pp->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 pcie_port *pp = &imx6_pcie->pp;
@@ -381,6 +417,10 @@ 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);
@@ -407,35 +447,44 @@ 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)
@@ -498,8 +547,11 @@ static int imx6_pcie_establish_link(struct imx6_pcie *imx6_pcie)
 	dw_pcie_writel_rc(pp, 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) {
@@ -674,13 +726,31 @@ 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 */
@@ -738,6 +808,7 @@ 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 */
-- 
2.9.3

[RESEND PATCH v5 2/4] PCI: imx6: Do not wait for speed change on i.MX7

[Andrey Smirnov]

As can be seen from [1]:

"...the different behavior between iMX6Q PCIe and iMX7D PCIe maybe
caused by the different controller version.

Regarding to the DOC description, the DIRECT_SPEED_CHANGE should be
cleared after the speed change from GEN1 to GEN2. Unfortunately, when
GEN1 device is used, the behavior is not documented.

So, IC design guys run the simulation and
find out the following behaviors:

     1. DIRECT_SPEED_CHANGE will be cleared in 7D after speed change
     	from GEN1 to GEN2. This matches doc’s description

     2. set MAX link speed(PCIE_CAP_TARGET_LINK_SPEED=0x01) as GEN1 and
     	re-run the simulation, DIRECT_SPEED_CHANGE will not be cleared;
     	remain as 1, this matches your result, but function test is
     	passed, so this bit should not affect the normal PCIe function.
..."

imx6_pcie_wait_for_speed_change will report false failures for Gen1 ->
Gen1 speed transition, so avoid doing that check and just rely on
imx6_pcie_wait_for_link only.

[1] https://community.nxp.com/message/867943

Cc: yurovsky@gmail.com
Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Fabio Estevam <fabio.estevam@nxp.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
---
 drivers/pci/host/pci-imx6.c | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/drivers/pci/host/pci-imx6.c b/drivers/pci/host/pci-imx6.c
index 2f3f375..473bbdc 100644
--- a/drivers/pci/host/pci-imx6.c
+++ b/drivers/pci/host/pci-imx6.c
@@ -577,10 +577,21 @@ static int imx6_pcie_establish_link(struct imx6_pcie *imx6_pcie)
 	tmp |= PORT_LOGIC_SPEED_CHANGE;
 	dw_pcie_writel_rc(pp, 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;
+	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! */
-- 
2.9.3

[RESEND PATCH v5 3/4] PCI: imx6: Do not switch speed if Gen2 is disabled

[Andrey Smirnov]

Save a bit of time and avoid going through link speed change procedure
in configuration where link max speed is limited to Gen1 in DT.

Cc: yurovsky@gmail.com
Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Fabio Estevam <fabio.estevam@nxp.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
---
 drivers/pci/host/pci-imx6.c | 52 ++++++++++++++++++++++-----------------------
 1 file changed, 26 insertions(+), 26 deletions(-)

diff --git a/drivers/pci/host/pci-imx6.c b/drivers/pci/host/pci-imx6.c
index 473bbdc..071251f3 100644
--- a/drivers/pci/host/pci-imx6.c
+++ b/drivers/pci/host/pci-imx6.c
@@ -565,40 +565,40 @@ 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_rc(pp, 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_rc(pp, PCIE_LINK_WIDTH_SPEED_CONTROL);
-	tmp |= PORT_LOGIC_SPEED_CHANGE;
-	dw_pcie_writel_rc(pp, 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.
+		 * Start Directed Speed Change so the best possible
+		 * speed both link partners support can be negotiated.
 		 */
+		tmp = dw_pcie_readl_rc(pp, PCIE_LINK_WIDTH_SPEED_CONTROL);
+		tmp |= PORT_LOGIC_SPEED_CHANGE;
+		dw_pcie_writel_rc(pp, 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;
+			}
+		}
 
-		ret = imx6_pcie_wait_for_speed_change(imx6_pcie);
+		/* 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_rc(pp, PCIE_RC_LCSR);
-- 
2.9.3

[RESEND PATCH v5 4/4] PCI: imx6: Allow probe deferal by reset GPIO

[Andrey Smirnov]

Some designs implement reset GPIO via a GPIO expander connected to a
peripheral bus. One such example would be i.MX7 Sabre board where said
GPIO is provided by SPI shift register connected to a bitbanged SPI
bus. In order to support such designs allow reset GPIO request to defer
probing of the driver.

Cc: yurovsky@gmail.com
Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Fabio Estevam <fabio.estevam@nxp.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
---
 drivers/pci/host/pci-imx6.c | 25 +++++++++++++++++--------
 1 file changed, 17 insertions(+), 8 deletions(-)

diff --git a/drivers/pci/host/pci-imx6.c b/drivers/pci/host/pci-imx6.c
index 071251f3..fe832e7f 100644
--- a/drivers/pci/host/pci-imx6.c
+++ b/drivers/pci/host/pci-imx6.c
@@ -638,8 +638,8 @@ static struct 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 pcie_port *pp = &imx6_pcie->pp;
 	struct device *dev = pp->dev;
@@ -674,7 +674,7 @@ static int __init imx6_add_pcie_port(struct imx6_pcie *imx6_pcie,
 	return 0;
 }
 
-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 imx6_pcie *imx6_pcie;
@@ -693,10 +693,6 @@ 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);
 	pp->dbi_base = devm_ioremap_resource(dev, dbi_base);
 	if (IS_ERR(pp->dbi_base))
@@ -716,6 +712,8 @@ 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 */
@@ -828,11 +826,22 @@ 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 unitialized 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);
-- 
2.9.3

Re: [RESEND PATCH v5 1/4] PCI: imx6: Add code to support i.MX7D

[Rob Herring]

On Mon, Feb 20, 2017 at 08:08:57AM -0800, Andrey Smirnov wrote:
> Add various bits of code needed to support i.MX7D variant of the IP.
> 
> Cc: yurovsky@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 <lee.jones@linaro.org>
> Cc: Fabio Estevam <fabio.estevam@nxp.com>
> Cc: linux-arm-kernel@lists.infradead.org
> Cc: devicetree@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
> Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
> ---
>  .../devicetree/bindings/pci/fsl,imx6q-pcie.txt     |  13 ++-

I guess the conclusion of the discussion is this is fine, so:

Acked-by: Rob Herring <robh@kernel.org>

>  drivers/pci/host/pci-imx6.c                        | 121 ++++++++++++++++-----
>  include/linux/mfd/syscon/imx7-iomuxc-gpr.h         |   4 +
>  3 files changed, 112 insertions(+), 26 deletions(-)

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [RESEND PATCH v5 1/4] PCI: imx6: Add code to support i.MX7D

[Lee Jones]

On Mon, 20 Feb 2017, Andrey Smirnov wrote:

> Add various bits of code needed to support i.MX7D variant of the IP.
> 
> Cc: yurovsky@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 <lee.jones@linaro.org>
> Cc: Fabio Estevam <fabio.estevam@nxp.com>
> Cc: linux-arm-kernel@lists.infradead.org
> Cc: devicetree@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
> Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
> ---
>  .../devicetree/bindings/pci/fsl,imx6q-pcie.txt     |  13 ++-
>  drivers/pci/host/pci-imx6.c                        | 121 ++++++++++++++++-----
>  include/linux/mfd/syscon/imx7-iomuxc-gpr.h         |   4 +
>  3 files changed, 112 insertions(+), 26 deletions(-)

I Acked the original v5 -- please carry it over.

> 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@0x01000000 {
> diff --git a/drivers/pci/host/pci-imx6.c b/drivers/pci/host/pci-imx6.c
> index 50a1291..2f3f375 100644
> --- a/drivers/pci/host/pci-imx6.c
> +++ b/drivers/pci/host/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
> @@ -251,6 +261,10 @@ static void imx6_pcie_assert_core_reset(struct imx6_pcie *imx6_pcie)
>  	u32 val, gpr1, gpr12;
>  
>  	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,
> @@ -333,11 +347,33 @@ 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 pcie_port *pp = &imx6_pcie->pp;
> +	struct device *dev = pp->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 pcie_port *pp = &imx6_pcie->pp;
> @@ -381,6 +417,10 @@ 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);
> @@ -407,35 +447,44 @@ 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)
> @@ -498,8 +547,11 @@ static int imx6_pcie_establish_link(struct imx6_pcie *imx6_pcie)
>  	dw_pcie_writel_rc(pp, 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) {
> @@ -674,13 +726,31 @@ 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 */
> @@ -738,6 +808,7 @@ 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 */

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
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