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
500ms waiting for training that will never happen, let's use the helper
function, of_get_pci_max_link_speed, to get the max link speed from DT
and specify link capability.
Signed-off-by: Brian Norris <briannorris@xxxxxxxxxxxx>
Signed-off-by: Shawn Lin <shawn.lin@xxxxxxxxxxxxxx>
---
Changes in v6:
- user helper function of_get_pci_max_link_speed and use gen2 by default
if finding any errors from of_get_pci_max_link_speed. It could be
backward compatibe to the old dtb. (Suggested by Rob)
Changes in v5:
- rebase the code since it isn't cleanly applied after Bjorn's cleanup
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.
drivers/pci/host/pcie-rockchip.c | 58 +++++++++++++++++++++++++---------------
1 file changed, 36 insertions(+), 22 deletions(-)
diff --git a/drivers/pci/host/pcie-rockchip.c b/drivers/pci/host/pcie-rockchip.c
index b3548d0..7125e35 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
@@ -200,6 +201,7 @@ struct rockchip_pcie {
struct gpio_desc *ep_gpio;
u32 lanes;
u8 root_bus_nr;
+ int link_gen;
struct device *dev;
struct irq_domain *irq_domain;
};
@@ -437,13 +439,19 @@ static int rockchip_pcie_init_port(struct rockchip_pcie *rockchip)
return err;
}
+ if (rockchip->link_gen == 2)
+ rockchip_writel(rockchip, PCIE_CLIENT_CONFIG,
+ PCIE_CLIENT_GEN_SEL_2);
+ else
+ rockchip_writel(rockchip, PCIE_CLIENT_CONFIG,
+ PCIE_CLIENT_GEN_SEL_1);
+
rockchip_writel(rockchip, PCIE_CLIENT_CONFIG,
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_MODE_RC);
err = phy_power_on(rockchip->phy);
if (err) {
@@ -519,29 +527,31 @@ 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_readl(rockchip, PCIE_RC_CONFIG_LCS);
- status |= PCIE_RC_CONFIG_LCS_RETRAIN_LINK;
- rockchip_writel(rockchip, PCIE_RC_CONFIG_LCS, status);
+ if (rockchip->link_gen == 2) {
+ /*
+ * Enable retrain for gen2. This should be configured
+ * only after gen1 finished.
+ */
+ status = rockchip_readl(rockchip, PCIE_RC_CONFIG_LCS);
+ status |= PCIE_RC_CONFIG_LCS_RETRAIN_LINK;
+ rockchip_writel(rockchip, PCIE_RC_CONFIG_LCS, status);
+
+ timeout = jiffies + msecs_to_jiffies(500);
+ for (;;) {
+ status = rockchip_readl(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_readl(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 */
@@ -747,6 +757,10 @@ static int rockchip_pcie_parse_dt(struct rockchip_pcie *rockchip)
rockchip->lanes = 1;
}
+ rockchip->link_gen = of_get_pci_max_link_speed(node);
+ if (rockchip->link_gen < 0 || rockchip->link_gen > 2)
+ rockchip->link_gen = 2;
+
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
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