From aaf87f03ad709ff9f00819ef1eb001e878ad0a54 Mon Sep 17 00:00:00 2001
From: Fabio Estevam <fabio.estevam@freescale.com>
Date: Tue, 13 Oct 2015 11:01:27 -0300
Subject: [PATCH] pci: pcie_imx: Fix hang on mx6qp

PCI driver currently hangs on mx6qp.

Toggle the reset bit with the appropriate timings to fix the issue.

Based on the FSL kernel driver implementation.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Acked-by: Stefano Babic <sbabic@denx.de>
---
 arch/arm/include/asm/arch-mx6/iomux.h | 2 ++
 drivers/pci/pcie_imx.c                | 8 ++++++++
 2 files changed, 10 insertions(+)

diff --git a/arch/arm/include/asm/arch-mx6/iomux.h b/arch/arm/include/asm/arch-mx6/iomux.h
index 9b3a91f076..907cb408ff 100644
--- a/arch/arm/include/asm/arch-mx6/iomux.h
+++ b/arch/arm/include/asm/arch-mx6/iomux.h
@@ -18,6 +18,8 @@
 #define IOMUXC_GPR1_REF_SSP_EN			(1 << 16)
 #define IOMUXC_GPR1_TEST_POWERDOWN		(1 << 18)
 
+#define IOMUXC_GPR1_PCIE_SW_RST		(1 << 29)
+
 /*
  * IOMUXC_GPR5 bit fields
  */
diff --git a/drivers/pci/pcie_imx.c b/drivers/pci/pcie_imx.c
index 1568f20c1a..f1e189edd5 100644
--- a/drivers/pci/pcie_imx.c
+++ b/drivers/pci/pcie_imx.c
@@ -19,6 +19,7 @@
 #include <asm/io.h>
 #include <linux/sizes.h>
 #include <errno.h>
+#include <asm/arch/sys_proto.h>
 
 #define PCI_ACCESS_READ  0
 #define PCI_ACCESS_WRITE 1
@@ -430,6 +431,10 @@ static int imx_pcie_write_config(struct pci_controller *hose, pci_dev_t d,
 static int imx6_pcie_assert_core_reset(void)
 {
 	struct iomuxc *iomuxc_regs = (struct iomuxc *)IOMUXC_BASE_ADDR;
+
+	if (is_mx6dqp())
+		setbits_le32(&iomuxc_regs->gpr[1], IOMUXC_GPR1_PCIE_SW_RST);
+
 #if defined(CONFIG_MX6SX)
 	struct gpc *gpc_regs = (struct gpc *)GPC_BASE_ADDR;
 
@@ -536,6 +541,9 @@ static int imx6_pcie_deassert_core_reset(void)
 
 	enable_pcie_clock();
 
+	if (is_mx6dqp())
+		clrbits_le32(&iomuxc_regs->gpr[1], IOMUXC_GPR1_PCIE_SW_RST);
+
 	/*
 	 * Wait for the clock to settle a bit, when the clock are sourced
 	 * from the CPU, we need about 30 ms to settle.
-- 
2.39.5