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PCI: rockchip: Specify the link capability

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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_pci_get_max_link_speed(), to get the max link speed from DT and specify
link capability.

Signed-off-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
This commit is contained in:
Shawn Lin 2016-12-07 15:05:59 -06:00 committed by Bjorn Helgaas
parent 45e9320f3a
commit f2fb5b8f2a
1 changed files with 38 additions and 24 deletions
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62
drivers/pci/host/pcie-rockchip.c
View file

@ -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
@ -208,6 +209,7 @@ 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;
};
@ -518,14 +520,20 @@ 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) {
@ -609,29 +617,31 @@ 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;
}
msleep(20);
}
if (time_after(jiffies, timeout)) {
dev_dbg(dev, "PCIe link training gen2 timeout, fall back to gen1!\n");
break;
}
msleep(20);
}
/* Check the final link width from negotiated lane counter from MGMT */
@ -840,6 +850,10 @@ static int rockchip_pcie_parse_dt(struct rockchip_pcie *rockchip)
rockchip->lanes = 1;
}
rockchip->link_gen = of_pci_get_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)