[PATCH 5/6] PCI: imx6: Force Gen1 operation

[Marek Vasut]

Without forcing the PCIe core into Gen1 operation, the PCIe switch
attached directly to the PCIe port is not recognised at all. The
PCIe switch is Gen2 capable to make this issue even more puzzling.

Signed-off-by: Marek Vasut <marex at denx.de>
Cc: Bjorn Helgaas <bhelgaas at google.com>
Cc: Frank Li <lznuaa at gmail.com>
Cc: Jingoo Han <jg1.han at samsung.com>
Cc: Mohit KUMAR <Mohit.KUMAR at st.com>
Cc: Pratyush Anand <pratyush.anand at st.com>
Cc: Richard Zhu <r65037 at freescale.com>
Cc: Sascha Hauer <s.hauer at pengutronix.de>
Cc: Sean Cross <xobs at kosagi.com>
Cc: Shawn Guo <shawn.guo at linaro.org>
Cc: Siva Reddy Kallam <siva.kallam at samsung.com>
Cc: Srikanth T Shivanand <ts.srikanth at samsung.com>
Cc: Tim Harvey <tharvey at gateworks.com>
Cc: Troy Kisky <troy.kisky at boundarydevices.com>
Cc: Yinghai Lu <yinghai at kernel.org>
---
 drivers/pci/host/pci-imx6.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/host/pci-imx6.c b/drivers/pci/host/pci-imx6.c
index ca8c5de..8402e9a 100644
--- a/drivers/pci/host/pci-imx6.c
+++ b/drivers/pci/host/pci-imx6.c
@@ -321,6 +321,7 @@ static void imx6_pcie_host_init(struct pcie_port *pp)
 {
 	int count = 0;
 	struct imx6_pcie *imx6_pcie = to_imx6_pcie(pp);
+	uint32_t tmp;
 
 	imx6_pcie_assert_core_reset(pp);
 
@@ -330,13 +331,23 @@ static void imx6_pcie_host_init(struct pcie_port *pp)
 
 	dw_pcie_setup_rc(pp);
 
+	/*
+	 * FIXME:
+	 * Force Gen1 operation. In case the IP block is in Gen2 operation
+	 * mode, it does not detect the PCIe switch at all.
+	 */
+	tmp = readl(pp->dbi_base + 0x7c);
+	tmp &= ~0xf;
+	tmp |= 0x1;
+	writel(tmp, pp->dbi_base + 0x7c);
+
 	regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
 			IMX6Q_GPR12_PCIE_CTL_2, 1 << 10);
 
 	while (!dw_pcie_link_up(pp)) {
 		usleep_range(100, 1000);
 		count++;
-		if (count >= 10) {
+		if (count >= 200) {
 			dev_err(pp->dev, "phy link never came up\n");
 			dev_dbg(pp->dev,
 				"DEBUG_R0: 0x%08x, DEBUG_R1: 0x%08x\n",
-- 
1.8.4.rc3