pci: mediatek: add PCIe controller support for MT7623
This adds PCIe controller support for MT7623.
This is adapted from the Linux version.
Tested-by: Frank Wunderlich <frank-w@public-files.de>
Signed-off-by: Frank Wunderlich <frank-w@public-files.de>
diff --git a/drivers/pci/pcie_mediatek.c b/drivers/pci/pcie_mediatek.c
new file mode 100644
index 0000000..a0dcb25
--- /dev/null
+++ b/drivers/pci/pcie_mediatek.c
@@ -0,0 +1,279 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * MediaTek PCIe host controller driver.
+ *
+ * Copyright (c) 2017-2019 MediaTek Inc.
+ * Author: Ryder Lee <ryder.lee@mediatek.com>
+ * Honghui Zhang <honghui.zhang@mediatek.com>
+ */
+
+#include <common.h>
+#include <clk.h>
+#include <dm.h>
+#include <generic-phy.h>
+#include <pci.h>
+#include <reset.h>
+#include <asm/io.h>
+#include <linux/iopoll.h>
+#include <linux/list.h>
+
+/* PCIe shared registers */
+#define PCIE_SYS_CFG 0x00
+#define PCIE_INT_ENABLE 0x0c
+#define PCIE_CFG_ADDR 0x20
+#define PCIE_CFG_DATA 0x24
+
+/* PCIe per port registers */
+#define PCIE_BAR0_SETUP 0x10
+#define PCIE_CLASS 0x34
+#define PCIE_LINK_STATUS 0x50
+
+#define PCIE_PORT_INT_EN(x) BIT(20 + (x))
+#define PCIE_PORT_PERST(x) BIT(1 + (x))
+#define PCIE_PORT_LINKUP BIT(0)
+#define PCIE_BAR_MAP_MAX GENMASK(31, 16)
+
+#define PCIE_BAR_ENABLE BIT(0)
+#define PCIE_REVISION_ID BIT(0)
+#define PCIE_CLASS_CODE (0x60400 << 8)
+#define PCIE_CONF_REG(regn) (((regn) & GENMASK(7, 2)) | \
+ ((((regn) >> 8) & GENMASK(3, 0)) << 24))
+#define PCIE_CONF_ADDR(regn, bdf) \
+ (PCIE_CONF_REG(regn) | (bdf))
+
+/* MediaTek specific configuration registers */
+#define PCIE_FTS_NUM 0x70c
+#define PCIE_FTS_NUM_MASK GENMASK(15, 8)
+#define PCIE_FTS_NUM_L0(x) ((x) & 0xff << 8)
+
+#define PCIE_FC_CREDIT 0x73c
+#define PCIE_FC_CREDIT_MASK (GENMASK(31, 31) | GENMASK(28, 16))
+#define PCIE_FC_CREDIT_VAL(x) ((x) << 16)
+
+struct mtk_pcie_port {
+ void __iomem *base;
+ struct list_head list;
+ struct mtk_pcie *pcie;
+ struct reset_ctl reset;
+ struct clk sys_ck;
+ struct phy phy;
+ u32 slot;
+};
+
+struct mtk_pcie {
+ void __iomem *base;
+ struct clk free_ck;
+ struct list_head ports;
+};
+
+static int mtk_pcie_config_address(struct udevice *udev, pci_dev_t bdf,
+ uint offset, void **paddress)
+{
+ struct mtk_pcie *pcie = dev_get_priv(udev);
+
+ writel(PCIE_CONF_ADDR(offset, bdf), pcie->base + PCIE_CFG_ADDR);
+ *paddress = pcie->base + PCIE_CFG_DATA + (offset & 3);
+
+ return 0;
+}
+
+static int mtk_pcie_read_config(struct udevice *bus, pci_dev_t bdf,
+ uint offset, ulong *valuep,
+ enum pci_size_t size)
+{
+ return pci_generic_mmap_read_config(bus, mtk_pcie_config_address,
+ bdf, offset, valuep, size);
+}
+
+static int mtk_pcie_write_config(struct udevice *bus, pci_dev_t bdf,
+ uint offset, ulong value,
+ enum pci_size_t size)
+{
+ return pci_generic_mmap_write_config(bus, mtk_pcie_config_address,
+ bdf, offset, value, size);
+}
+
+static const struct dm_pci_ops mtk_pcie_ops = {
+ .read_config = mtk_pcie_read_config,
+ .write_config = mtk_pcie_write_config,
+};
+
+static void mtk_pcie_port_free(struct mtk_pcie_port *port)
+{
+ list_del(&port->list);
+ free(port);
+}
+
+static int mtk_pcie_startup_port(struct mtk_pcie_port *port)
+{
+ struct mtk_pcie *pcie = port->pcie;
+ u32 slot = PCI_DEV(port->slot << 11);
+ u32 val;
+ int err;
+
+ /* assert port PERST_N */
+ setbits_le32(pcie->base + PCIE_SYS_CFG, PCIE_PORT_PERST(port->slot));
+ /* de-assert port PERST_N */
+ clrbits_le32(pcie->base + PCIE_SYS_CFG, PCIE_PORT_PERST(port->slot));
+
+ /* 100ms timeout value should be enough for Gen1/2 training */
+ err = readl_poll_timeout(port->base + PCIE_LINK_STATUS, val,
+ !!(val & PCIE_PORT_LINKUP), 100000);
+ if (err)
+ return -ETIMEDOUT;
+
+ /* disable interrupt */
+ clrbits_le32(pcie->base + PCIE_INT_ENABLE,
+ PCIE_PORT_INT_EN(port->slot));
+
+ /* map to all DDR region. We need to set it before cfg operation. */
+ writel(PCIE_BAR_MAP_MAX | PCIE_BAR_ENABLE,
+ port->base + PCIE_BAR0_SETUP);
+
+ /* configure class code and revision ID */
+ writel(PCIE_CLASS_CODE | PCIE_REVISION_ID, port->base + PCIE_CLASS);
+
+ /* configure FC credit */
+ writel(PCIE_CONF_ADDR(PCIE_FC_CREDIT, slot),
+ pcie->base + PCIE_CFG_ADDR);
+ clrsetbits_le32(pcie->base + PCIE_CFG_DATA, PCIE_FC_CREDIT_MASK,
+ PCIE_FC_CREDIT_VAL(0x806c));
+
+ /* configure RC FTS number to 250 when it leaves L0s */
+ writel(PCIE_CONF_ADDR(PCIE_FTS_NUM, slot), pcie->base + PCIE_CFG_ADDR);
+ clrsetbits_le32(pcie->base + PCIE_CFG_DATA, PCIE_FTS_NUM_MASK,
+ PCIE_FTS_NUM_L0(0x50));
+
+ return 0;
+}
+
+static void mtk_pcie_enable_port(struct mtk_pcie_port *port)
+{
+ int err;
+
+ err = clk_enable(&port->sys_ck);
+ if (err)
+ goto exit;
+
+ err = reset_assert(&port->reset);
+ if (err)
+ goto exit;
+
+ err = reset_deassert(&port->reset);
+ if (err)
+ goto exit;
+
+ err = generic_phy_init(&port->phy);
+ if (err)
+ goto exit;
+
+ err = generic_phy_power_on(&port->phy);
+ if (err)
+ goto exit;
+
+ if (!mtk_pcie_startup_port(port))
+ return;
+
+ pr_err("Port%d link down\n", port->slot);
+exit:
+ mtk_pcie_port_free(port);
+}
+
+static int mtk_pcie_parse_port(struct udevice *dev, u32 slot)
+{
+ struct mtk_pcie *pcie = dev_get_priv(dev);
+ struct mtk_pcie_port *port;
+ char name[10];
+ int err;
+
+ port = devm_kzalloc(dev, sizeof(*port), GFP_KERNEL);
+ if (!port)
+ return -ENOMEM;
+
+ snprintf(name, sizeof(name), "port%d", slot);
+ port->base = dev_remap_addr_name(dev, name);
+ if (!port->base)
+ return -ENOENT;
+
+ snprintf(name, sizeof(name), "sys_ck%d", slot);
+ err = clk_get_by_name(dev, name, &port->sys_ck);
+ if (err)
+ return err;
+
+ err = reset_get_by_index(dev, slot, &port->reset);
+ if (err)
+ return err;
+
+ err = generic_phy_get_by_index(dev, slot, &port->phy);
+ if (err)
+ return err;
+
+ port->slot = slot;
+ port->pcie = pcie;
+
+ INIT_LIST_HEAD(&port->list);
+ list_add_tail(&port->list, &pcie->ports);
+
+ return 0;
+}
+
+static int mtk_pcie_probe(struct udevice *dev)
+{
+ struct mtk_pcie *pcie = dev_get_priv(dev);
+ struct mtk_pcie_port *port, *tmp;
+ ofnode subnode;
+ int err;
+
+ INIT_LIST_HEAD(&pcie->ports);
+
+ pcie->base = dev_remap_addr_name(dev, "subsys");
+ if (!pcie->base)
+ return -ENOENT;
+
+ err = clk_get_by_name(dev, "free_ck", &pcie->free_ck);
+ if (err)
+ return err;
+
+ /* enable top level clock */
+ err = clk_enable(&pcie->free_ck);
+ if (err)
+ return err;
+
+ dev_for_each_subnode(subnode, dev) {
+ struct fdt_pci_addr addr;
+ u32 slot = 0;
+
+ if (!ofnode_is_available(subnode))
+ continue;
+
+ err = ofnode_read_pci_addr(subnode, 0, "reg", &addr);
+ if (err)
+ return err;
+
+ slot = PCI_DEV(addr.phys_hi);
+
+ err = mtk_pcie_parse_port(dev, slot);
+ if (err)
+ return err;
+ }
+
+ /* enable each port, and then check link status */
+ list_for_each_entry_safe(port, tmp, &pcie->ports, list)
+ mtk_pcie_enable_port(port);
+
+ return 0;
+}
+
+static const struct udevice_id mtk_pcie_ids[] = {
+ { .compatible = "mediatek,mt7623-pcie", },
+ { }
+};
+
+U_BOOT_DRIVER(pcie_mediatek) = {
+ .name = "pcie_mediatek",
+ .id = UCLASS_PCI,
+ .of_match = mtk_pcie_ids,
+ .ops = &mtk_pcie_ops,
+ .probe = mtk_pcie_probe,
+ .priv_auto_alloc_size = sizeof(struct mtk_pcie),
+};