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Subject[PATCH v2 1/5] PCI: mediatek: Add a structure to abstract the controller generations
Date
From: Ryder Lee <ryder.lee@mediatek.com>

Introduce a structure "mtk_pcie_soc" to abstract the differences between
controller generations, and the .startup() hook is used to encapsulate
some SoC-dependent related setting. In doing so, the common code which
will be reused by future chips.

In addition, we change the approaches to waiting Gen2 training by using
readl_poll_timeout() calls.

Signed-off-by: Ryder Lee <ryder.lee@mediatek.com>
Signed-off-by: Honghui Zhang <honghui.zhang@mediatek.com>
---
drivers/pci/host/pcie-mediatek.c | 81 +++++++++++++++++++++++-----------------
1 file changed, 47 insertions(+), 34 deletions(-)

diff --git a/drivers/pci/host/pcie-mediatek.c b/drivers/pci/host/pcie-mediatek.c
index 5a9d858..7f952a4 100644
--- a/drivers/pci/host/pcie-mediatek.c
+++ b/drivers/pci/host/pcie-mediatek.c
@@ -16,6 +16,7 @@

#include <linux/clk.h>
#include <linux/delay.h>
+#include <linux/iopoll.h>
#include <linux/kernel.h>
#include <linux/of_address.h>
#include <linux/of_pci.h>
@@ -63,6 +64,18 @@
#define PCIE_FC_CREDIT_MASK (GENMASK(31, 31) | GENMASK(28, 16))
#define PCIE_FC_CREDIT_VAL(x) ((x) << 16)

+struct mtk_pcie_port;
+
+/**
+ * struct mtk_pcie_soc - differentiate between host generations
+ * @ops: pointer to configuration access functions
+ * @startup: pointer to controller setting functions
+ */
+struct mtk_pcie_soc {
+ struct pci_ops *ops;
+ int (*startup)(struct mtk_pcie_port *port);
+};
+
/**
* struct mtk_pcie_port - PCIe port information
* @base: IO mapped register base
@@ -96,6 +109,7 @@ struct mtk_pcie_port {
* @busn: bus range
* @offset: IO / Memory offset
* @ports: pointer to PCIe port information
+ * @soc: pointer to SoC-dependent operations
*/
struct mtk_pcie {
struct device *dev;
@@ -111,13 +125,9 @@ struct mtk_pcie {
resource_size_t io;
} offset;
struct list_head ports;
+ const struct mtk_pcie_soc *soc;
};

-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)
{
struct device *dev = pcie->dev;
@@ -171,12 +181,30 @@ static struct pci_ops mtk_pcie_ops = {
.write = pci_generic_config_write,
};

-static void mtk_pcie_configure_rc(struct mtk_pcie_port *port)
+static int mtk_pcie_startup_ports(struct mtk_pcie_port *port)
{
struct mtk_pcie *pcie = port->pcie;
u32 func = PCI_FUNC(port->index << 3);
u32 slot = PCI_SLOT(port->index << 3);
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 */
val = readl(pcie->base + PCIE_INT_ENABLE);
@@ -209,30 +237,14 @@ static void mtk_pcie_configure_rc(struct mtk_pcie_port *port)
writel(PCIE_CONF_ADDR(PCIE_FTS_NUM, func, slot, 0),
pcie->base + PCIE_CFG_ADDR);
writel(val, pcie->base + PCIE_CFG_DATA);
-}

-static void mtk_pcie_assert_ports(struct mtk_pcie_port *port)
-{
- 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);
+ return 0;
}

static void mtk_pcie_enable_ports(struct mtk_pcie_port *port)
{
- struct device *dev = port->pcie->dev;
+ struct mtk_pcie *pcie = port->pcie;
+ struct device *dev = pcie->dev;
int err;

err = clk_prepare_enable(port->sys_ck);
@@ -250,13 +262,8 @@ static void mtk_pcie_enable_ports(struct mtk_pcie_port *port)
goto err_phy_on;
}

- mtk_pcie_assert_ports(port);
-
- /* if link up, then setup root port configuration space */
- if (mtk_pcie_link_up(port)) {
- mtk_pcie_configure_rc(port);
+ if (!pcie->soc->startup(port))
return;
- }

dev_info(dev, "Port%d link down\n", port->index);

@@ -480,7 +487,7 @@ static int mtk_pcie_register_host(struct pci_host_bridge *host)

host->busnr = pcie->busn.start;
host->dev.parent = pcie->dev;
- host->ops = &mtk_pcie_ops;
+ host->ops = pcie->soc->ops;
host->map_irq = of_irq_parse_and_map_pci;
host->swizzle_irq = pci_common_swizzle;

@@ -513,6 +520,7 @@ static int mtk_pcie_probe(struct platform_device *pdev)
pcie = pci_host_bridge_priv(host);

pcie->dev = dev;
+ pcie->soc = of_device_get_match_data(dev);
platform_set_drvdata(pdev, pcie);
INIT_LIST_HEAD(&pcie->ports);

@@ -537,9 +545,14 @@ static int mtk_pcie_probe(struct platform_device *pdev)
return err;
}

+static struct mtk_pcie_soc mtk_pcie_soc_v1 = {
+ .ops = &mtk_pcie_ops,
+ .startup = mtk_pcie_startup_ports,
+};
+
static const struct of_device_id mtk_pcie_ids[] = {
- { .compatible = "mediatek,mt7623-pcie"},
- { .compatible = "mediatek,mt2701-pcie"},
+ { .compatible = "mediatek,mt2701-pcie", .data = &mtk_pcie_soc_v1 },
+ { .compatible = "mediatek,mt7623-pcie", .data = &mtk_pcie_soc_v1 },
{},
};

--
2.6.4
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