From 51ed2c2b60265006bde7531d10993cf24def0aee Mon Sep 17 00:00:00 2001 From: Sham Muthayyan Date: Mon, 15 Jun 2020 23:06:07 +0200 Subject: PCI: qcom: Support pci speed set for ipq806x Some SoC based on ipq8064/5 needs to be limited to pci GEN1 speed due to some hardware limitations. Add support for speed setting defined by the max-link-speed binding. If not defined the max speed is set to GEN2 by default. Link: https://lore.kernel.org/r/20200615210608.21469-12-ansuelsmth@gmail.com Signed-off-by: Sham Muthayyan Signed-off-by: Ansuel Smith Signed-off-by: Lorenzo Pieralisi Reviewed-by: Rob Herring Acked-by: Stanimir Varbanov --- Backported with light changes: * One include is missing in kernel 5.4 drivers/pci/controller/dwc/pcie-qcom.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) --- a/drivers/pci/controller/dwc/pcie-qcom.c +++ b/drivers/pci/controller/dwc/pcie-qcom.c @@ -27,6 +27,7 @@ #include #include +#include "../../pci.h" #include "pcie-designware.h" #define PCIE20_PARF_SYS_CTRL 0x00 @@ -98,6 +99,8 @@ #define PCIE20_v3_PARF_SLV_ADDR_SPACE_SIZE 0x358 #define SLV_ADDR_SPACE_SZ 0x10000000 +#define PCIE20_LNK_CONTROL2_LINK_STATUS2 0xa0 + #define QCOM_PCIE_2_1_0_MAX_SUPPLY 3 #define QCOM_PCIE_2_1_0_MAX_CLOCKS 5 struct qcom_pcie_resources_2_1_0 { @@ -184,6 +187,7 @@ struct qcom_pcie { struct phy *phy; struct gpio_desc *reset; const struct qcom_pcie_ops *ops; + int gen; }; #define to_qcom_pcie(x) dev_get_drvdata((x)->dev) @@ -397,6 +401,11 @@ static int qcom_pcie_init_2_1_0(struct q /* wait for clock acquisition */ usleep_range(1000, 1500); + if (pcie->gen == 1) { + val = readl(pci->dbi_base + PCIE20_LNK_CONTROL2_LINK_STATUS2); + val |= PCI_EXP_LNKSTA_CLS_2_5GB; + writel(val, pci->dbi_base + PCIE20_LNK_CONTROL2_LINK_STATUS2); + } /* Set the Max TLP size to 2K, instead of using default of 4K */ writel(CFG_REMOTE_RD_REQ_BRIDGE_SIZE_2K, @@ -1261,6 +1270,10 @@ static int qcom_pcie_probe(struct platfo goto err_pm_runtime_put; } + pcie->gen = of_pci_get_max_link_speed(pdev->dev.of_node); + if (pcie->gen < 0) + pcie->gen = 2; + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "parf"); pcie->parf = devm_ioremap_resource(dev, res); if (IS_ERR(pcie->parf)) {