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PCI: mediatek: Use readl_poll_timeout() to wait for Gen2 training 

Wait for Gen2 training with readl_poll_timeout(), and simplify the hardware
assert logical by merging it into a new mtk_pcie_startup_port() interface.

Signed-off-by: Ryder Lee <ryder.lee@mediatek.com>
Signed-off-by: Honghui Zhang <honghui.zhang@mediatek.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
This commit is contained in:
Ryder Lee 2017-08-10 14:34:54 +08:00 committed by Bjorn Helgaas
parent 608fcac7ce
commit e10b7a184c
1 changed files with 22 additions and 30 deletions
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52
drivers/pci/host/pcie-mediatek.c
View File

@ -16,6 +16,7 @@
#include <linux/clk.h> #include <linux/clk.h>
#include <linux/delay.h> #include <linux/delay.h>
#include <linux/iopoll.h>
#include <linux/kernel.h> #include <linux/kernel.h>
#include <linux/of_address.h> #include <linux/of_address.h>
#include <linux/of_pci.h> #include <linux/of_pci.h>
@ -113,11 +114,6 @@ struct mtk_pcie {
struct list_head ports; struct list_head ports;
}; };
static inline bool mtk_pcie_link_up(struct mtk_pcie_port *port)
{
return !!(readl(port->base + PCIE_LINK_STATUS) & PCIE_PORT_LINKUP);
}
static void mtk_pcie_subsys_powerdown(struct mtk_pcie *pcie) static void mtk_pcie_subsys_powerdown(struct mtk_pcie *pcie)
{ {
struct device *dev = pcie->dev; struct device *dev = pcie->dev;
@ -171,12 +167,30 @@ static struct pci_ops mtk_pcie_ops = {
.write = pci_generic_config_write, .write = pci_generic_config_write,
}; };
static void mtk_pcie_configure_rc(struct mtk_pcie_port *port) static int mtk_pcie_startup_port(struct mtk_pcie_port *port)
{ {
struct mtk_pcie *pcie = port->pcie; struct mtk_pcie *pcie = port->pcie;
u32 func = PCI_FUNC(port->index << 3); u32 func = PCI_FUNC(port->index << 3);
u32 slot = PCI_SLOT(port->index << 3); u32 slot = PCI_SLOT(port->index << 3);
u32 val; u32 val;
int err;
/* assert port PERST_N */
val = readl(pcie->base + PCIE_SYS_CFG);
val |= PCIE_PORT_PERST(port->index);
writel(val, pcie->base + PCIE_SYS_CFG);
/* de-assert port PERST_N */
val = readl(pcie->base + PCIE_SYS_CFG);
val &= ~PCIE_PORT_PERST(port->index);
writel(val, pcie->base + PCIE_SYS_CFG);
/* 100ms timeout value should be enough for Gen1/2 training */
err = readl_poll_timeout(port->base + PCIE_LINK_STATUS, val,
!!(val & PCIE_PORT_LINKUP), 20,
100 * USEC_PER_MSEC);
if (err)
return -ETIMEDOUT;
/* enable interrupt */ /* enable interrupt */
val = readl(pcie->base + PCIE_INT_ENABLE); val = readl(pcie->base + PCIE_INT_ENABLE);
@ -209,25 +223,8 @@ static void mtk_pcie_configure_rc(struct mtk_pcie_port *port)
writel(PCIE_CONF_ADDR(PCIE_FTS_NUM, func, slot, 0), writel(PCIE_CONF_ADDR(PCIE_FTS_NUM, func, slot, 0),
pcie->base + PCIE_CFG_ADDR); pcie->base + PCIE_CFG_ADDR);
writel(val, pcie->base + PCIE_CFG_DATA); writel(val, pcie->base + PCIE_CFG_DATA);
}
static void mtk_pcie_assert_ports(struct mtk_pcie_port *port) return 0;
{
struct mtk_pcie *pcie = port->pcie;
u32 val;
/* assert port PERST_N */
val = readl(pcie->base + PCIE_SYS_CFG);
val |= PCIE_PORT_PERST(port->index);
writel(val, pcie->base + PCIE_SYS_CFG);
/* de-assert port PERST_N */
val = readl(pcie->base + PCIE_SYS_CFG);
val &= ~PCIE_PORT_PERST(port->index);
writel(val, pcie->base + PCIE_SYS_CFG);
/* PCIe v2.0 need at least 100ms delay to train from Gen1 to Gen2 */
msleep(100);
} }
static void mtk_pcie_enable_ports(struct mtk_pcie_port *port) static void mtk_pcie_enable_ports(struct mtk_pcie_port *port)
@ -250,13 +247,8 @@ static void mtk_pcie_enable_ports(struct mtk_pcie_port *port)
goto err_phy_on; goto err_phy_on;
} }
mtk_pcie_assert_ports(port); if (!mtk_pcie_startup_port(port))
/* if link up, then setup root port configuration space */
if (mtk_pcie_link_up(port)) {
mtk_pcie_configure_rc(port);
return; return;
}
dev_info(dev, "Port%d link down\n", port->index); dev_info(dev, "Port%d link down\n", port->index);