From: Brian Norris <briannorris@xxxxxxxxxxxx> rk3399 supports PCIe 2.x link speeds marginally at best, and on some boards, the link won't train at 5 GT/s at all. Rather than sacrifice 500 ms waiting for training that will never happen, let's add a property from devicetree to specify link capability. Signed-off-by: Brian Norris <briannorris@xxxxxxxxxxxx> Signed-off-by: Shawn Lin <shawn.lin@xxxxxxxxxxxxxx> --- Changes in v4: - define link_gen as u32 - elaborate more for rockchip,max-link-speed on doc Changes in v3: - Cast a warning for invalid max link speed and use gen1 for it. That looks better than v2. (Suggested by Brian) Changes in v2: - rename the property to rockchip,max-link-speed according to Bjorn's recommendation and take some bits from imx6q-pcie to make this requirement more consisent. .../devicetree/bindings/pci/rockchip-pcie.txt | 4 ++ drivers/pci/host/pcie-rockchip.c | 63 ++++++++++++++-------- 2 files changed, 44 insertions(+), 23 deletions(-) diff --git a/Documentation/devicetree/bindings/pci/rockchip-pcie.txt b/Documentation/devicetree/bindings/pci/rockchip-pcie.txt index ba67b39..9bb29de 100644 --- a/Documentation/devicetree/bindings/pci/rockchip-pcie.txt +++ b/Documentation/devicetree/bindings/pci/rockchip-pcie.txt @@ -42,6 +42,10 @@ Required properties: Optional Property: - ep-gpios: contain the entry for pre-reset gpio - num-lanes: number of lanes to use +- rockchip,max-link-speed: Specify PCI gen for link capability. Must + be '2' for gen2, and '1' for gen1, otherwise will default to gen1. + For backward compatibility, if this property isn't assigned, we + use gen2 by default. - vpcie3v3-supply: The phandle to the 3.3v regulator to use for PCIe. - vpcie1v8-supply: The phandle to the 1.8v regulator to use for PCIe. - vpcie0v9-supply: The phandle to the 0.9v regulator to use for PCIe. diff --git a/drivers/pci/host/pcie-rockchip.c b/drivers/pci/host/pcie-rockchip.c index 35591b1..6dde999 100644 --- a/drivers/pci/host/pcie-rockchip.c +++ b/drivers/pci/host/pcie-rockchip.c @@ -53,6 +53,7 @@ #define PCIE_CLIENT_ARI_ENABLE HIWORD_UPDATE_BIT(0x0008) #define PCIE_CLIENT_CONF_LANE_NUM(x) HIWORD_UPDATE(0x0030, ENCODE_LANES(x)) #define PCIE_CLIENT_MODE_RC HIWORD_UPDATE_BIT(0x0040) +#define PCIE_CLIENT_GEN_SEL_1 HIWORD_UPDATE(0x0080, 0) #define PCIE_CLIENT_GEN_SEL_2 HIWORD_UPDATE_BIT(0x0080) #define PCIE_CLIENT_BASIC_STATUS1 (PCIE_CLIENT_BASE + 0x48) #define PCIE_CLIENT_LINK_STATUS_UP 0x00300000 @@ -205,6 +206,7 @@ struct rockchip_pcie { struct gpio_desc *ep_gpio; u32 lanes; u8 root_bus_nr; + u32 link_gen; struct device *dev; struct irq_domain *irq_domain; }; @@ -443,14 +445,19 @@ static int rockchip_pcie_init_port(struct rockchip_pcie *rockchip) return err; } + if (rockchip->link_gen == 2) + rockchip_pcie_write(rockchip, PCIE_CLIENT_GEN_SEL_2, + PCIE_CLIENT_CONFIG); + else + rockchip_pcie_write(rockchip, PCIE_CLIENT_GEN_SEL_1, + PCIE_CLIENT_CONFIG); + rockchip_pcie_write(rockchip, PCIE_CLIENT_CONF_ENABLE | PCIE_CLIENT_LINK_TRAIN_ENABLE | PCIE_CLIENT_ARI_ENABLE | PCIE_CLIENT_CONF_LANE_NUM(rockchip->lanes) | - PCIE_CLIENT_MODE_RC | - PCIE_CLIENT_GEN_SEL_2, - PCIE_CLIENT_CONFIG); + PCIE_CLIENT_MODE_RC, PCIE_CLIENT_CONFIG); err = phy_power_on(rockchip->phy); if (err) { @@ -550,29 +557,31 @@ static int rockchip_pcie_init_port(struct rockchip_pcie *rockchip) msleep(20); } - /* - * Enable retrain for gen2. This should be configured only after - * gen1 finished. - */ - status = rockchip_pcie_read(rockchip, PCIE_RC_CONFIG_LCS); - status |= PCIE_RC_CONFIG_LCS_RETRAIN_LINK; - rockchip_pcie_write(rockchip, status, PCIE_RC_CONFIG_LCS); + if (rockchip->link_gen == 2) { + /* + * Enable retrain for gen2. This should be configured only after + * gen1 finished. + */ + status = rockchip_pcie_read(rockchip, PCIE_RC_CONFIG_LCS); + status |= PCIE_RC_CONFIG_LCS_RETRAIN_LINK; + rockchip_pcie_write(rockchip, status, PCIE_RC_CONFIG_LCS); + + timeout = jiffies + msecs_to_jiffies(500); + for (;;) { + status = rockchip_pcie_read(rockchip, PCIE_CORE_CTRL); + if ((status & PCIE_CORE_PL_CONF_SPEED_MASK) == + PCIE_CORE_PL_CONF_SPEED_5G) { + dev_dbg(dev, "PCIe link training gen2 pass!\n"); + break; + } - timeout = jiffies + msecs_to_jiffies(500); - for (;;) { - status = rockchip_pcie_read(rockchip, PCIE_CORE_CTRL); - if ((status & PCIE_CORE_PL_CONF_SPEED_MASK) == - PCIE_CORE_PL_CONF_SPEED_5G) { - dev_dbg(dev, "PCIe link training gen2 pass!\n"); - break; - } + if (time_after(jiffies, timeout)) { + dev_dbg(dev, "PCIe link training gen2 timeout, fall back to gen1!\n"); + break; + } - if (time_after(jiffies, timeout)) { - dev_dbg(dev, "PCIe link training gen2 timeout, fall back to gen1!\n"); - break; + msleep(20); } - - msleep(20); } /* Check the final link width from negotiated lane counter from MGMT */ @@ -781,6 +790,14 @@ static int rockchip_pcie_parse_dt(struct rockchip_pcie *rockchip) rockchip->lanes = 1; } + rockchip->link_gen = 2; + err = of_property_read_u32(node, "rockchip,max-link-speed", + &rockchip->link_gen); + if (!err && rockchip->link_gen != 1 && rockchip->link_gen != 2) { + dev_warn(dev, "invalid max-link-speed, default to use gen1\n"); + rockchip->link_gen = 1; + } + rockchip->core_rst = devm_reset_control_get(dev, "core"); if (IS_ERR(rockchip->core_rst)) { if (PTR_ERR(rockchip->core_rst) != -EPROBE_DEFER) -- 2.3.7 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html