PCI: mediatek: Add PCIe support for MT7622

This patch adds PCIe support for the Mediatek MT7622 SOC.

Signed-off-by: Chuanjia Liu <Chuanjia.Liu@mediatek.com>
Signed-off-by: Henry Yen <henry.yen@mediatek.com>

1 files changed, 459 insertions, 3 deletions

diff --git a/drivers/pci/pcie_mediatek.c b/drivers/pci/pcie_mediatek.c
index 6e6375cec0..ad34f7c597 100644
--- a/drivers/pci/pcie_mediatek.c
+++ b/drivers/pci/pcie_mediatek.c
@@ -20,6 +20,7 @@
 #include <linux/bitops.h>
 #include <linux/iopoll.h>
 #include <linux/list.h>
+#include "pci_internal.h"
 
 /* PCIe shared registers */
 #define PCIE_SYS_CFG		0x00
@@ -54,18 +55,90 @@
 #define PCIE_FC_CREDIT_MASK	(GENMASK(31, 31) | GENMASK(28, 16))
 #define PCIE_FC_CREDIT_VAL(x)	((x) << 16)
 
+/* PCIe V2 share registers */
+#define PCIE_SYS_CFG_V2		0x0
+#define PCIE_CSR_LTSSM_EN(x)	BIT(0 + (x) * 8)
+#define PCIE_CSR_ASPM_L1_EN(x)	BIT(1 + (x) * 8)
+
+/* PCIe V2 per-port registers */
+#define PCIE_CONF_VEND_ID	0x100
+#define PCIE_CONF_DEVICE_ID	0x102
+#define PCIE_CONF_CLASS_ID	0x106
+
+#define PCIE_AHB_TRANS_BASE0_L	0x438
+#define PCIE_AHB_TRANS_BASE0_H	0x43c
+#define AHB2PCIE_SIZE(x)	((x) & GENMASK(4, 0))
+#define PCIE_AXI_WINDOW0	0x448
+#define WIN_ENABLE		BIT(7)
+
+/*
+ * Define PCIe to AHB window size as 2^33 to support max 8GB address space
+ * translate, support least 4GB DRAM size access from EP DMA(physical DRAM
+ * start from 0x40000000).
+ */
+#define PCIE2AHB_SIZE	0x21
+
+/* PCIe V2 configuration transaction header */
+#define PCIE_CFG_HEADER0	0x460
+#define PCIE_CFG_HEADER1	0x464
+#define PCIE_CFG_HEADER2	0x468
+#define PCIE_CFG_WDATA		0x470
+#define PCIE_APP_TLP_REQ	0x488
+#define PCIE_CFG_RDATA		0x48c
+#define APP_CFG_REQ		BIT(0)
+#define APP_CPL_STATUS		GENMASK(7, 5)
+
+#define CFG_WRRD_TYPE_0		4
+#define CFG_WR_FMT		2
+#define CFG_RD_FMT		0
+
+#define CFG_DW0_LENGTH(length)	((length) & GENMASK(9, 0))
+#define CFG_DW0_TYPE(type)	(((type) << 24) & GENMASK(28, 24))
+#define CFG_DW0_FMT(fmt)	(((fmt) << 29) & GENMASK(31, 29))
+#define CFG_DW2_REGN(regn)	((regn) & GENMASK(11, 2))
+#define CFG_DW2_FUN(fun)	(((fun) << 16) & GENMASK(18, 16))
+#define CFG_DW2_DEV(dev)	(((dev) << 19) & GENMASK(23, 19))
+#define CFG_DW2_BUS(bus)	(((bus) << 24) & GENMASK(31, 24))
+#define CFG_HEADER_DW0(type, fmt) \
+	(CFG_DW0_LENGTH(1) | CFG_DW0_TYPE(type) | CFG_DW0_FMT(fmt))
+#define CFG_HEADER_DW1(where, size) \
+	(GENMASK(((size) - 1), 0) << ((where) & 0x3))
+#define CFG_HEADER_DW2(regn, fun, dev, bus) \
+	(CFG_DW2_REGN(regn) | CFG_DW2_FUN(fun) | \
+	CFG_DW2_DEV(dev) | CFG_DW2_BUS(bus))
+
+#define PCIE_RST_CTRL		0x510
+#define PCIE_PHY_RSTB		BIT(0)
+#define PCIE_PIPE_SRSTB		BIT(1)
+#define PCIE_MAC_SRSTB		BIT(2)
+#define PCIE_CRSTB		BIT(3)
+#define PCIE_PERSTB		BIT(8)
+#define PCIE_LINKDOWN_RST_EN	GENMASK(15, 13)
+#define PCIE_LINK_STATUS_V2	0x804
+#define PCIE_PORT_LINKUP_V2	BIT(11)
+
+#define PCI_VENDOR_ID_MEDIATEK	0x14c3
+
+enum MTK_PCIE_GEN {PCIE_V1, PCIE_V2, PCIE_V3};
+
 struct mtk_pcie_port {
 	void __iomem *base;
 	struct list_head list;
 	struct mtk_pcie *pcie;
 	struct reset_ctl reset;
 	struct clk sys_ck;
+	struct clk ahb_ck;
+	struct clk axi_ck;
+	struct clk aux_ck;
+	struct clk obff_ck;
+	struct clk pipe_ck;
 	struct phy phy;
 	u32 slot;
 };
 
 struct mtk_pcie {
 	void __iomem *base;
+	void *priv;
 	struct clk free_ck;
 	struct list_head ports;
 };
@@ -102,6 +175,152 @@ static const struct dm_pci_ops mtk_pcie_ops = {
 	.write_config	= mtk_pcie_write_config,
 };
 
+static int mtk_pcie_check_cfg_cpld(struct mtk_pcie_port *port)
+{
+	u32 val;
+	int err;
+
+	err = readl_poll_timeout(port->base + PCIE_APP_TLP_REQ, val,
+				 !(val & APP_CFG_REQ), 100 * 1000);
+	if (err)
+		return -1;
+
+	if (readl(port->base + PCIE_APP_TLP_REQ) & APP_CPL_STATUS)
+		return -1;
+
+	return 0;
+}
+
+static int mtk_pcie_hw_rd_cfg(struct mtk_pcie_port *port, u32 bus, pci_dev_t devfn,
+			      int where, int size, ulong *val)
+{
+	u32 tmp;
+
+	writel(CFG_HEADER_DW0(CFG_WRRD_TYPE_0, CFG_RD_FMT),
+	       port->base + PCIE_CFG_HEADER0);
+	writel(CFG_HEADER_DW1(where, size), port->base + PCIE_CFG_HEADER1);
+	writel(CFG_HEADER_DW2(where, PCI_FUNC(devfn), PCI_DEV(devfn), bus),
+	       port->base + PCIE_CFG_HEADER2);
+
+	/* Trigger h/w to transmit Cfgrd TLP */
+	tmp = readl(port->base + PCIE_APP_TLP_REQ);
+	tmp |= APP_CFG_REQ;
+	writel(tmp, port->base + PCIE_APP_TLP_REQ);
+
+	/* Check completion status */
+	if (mtk_pcie_check_cfg_cpld(port))
+		return -1;
+
+	/* Read cpld payload of Cfgrd */
+	*val = readl(port->base + PCIE_CFG_RDATA);
+
+	if (size == 1)
+		*val = (*val >> (8 * (where & 3))) & 0xff;
+	else if (size == 2)
+		*val = (*val >> (8 * (where & 3))) & 0xffff;
+
+	return 0;
+}
+
+static int mtk_pcie_hw_wr_cfg(struct mtk_pcie_port *port, u32 bus, pci_dev_t devfn,
+			      int where, int size, u32 val)
+{
+	/* Write PCIe configuration transaction header for Cfgwr */
+	writel(CFG_HEADER_DW0(CFG_WRRD_TYPE_0, CFG_WR_FMT),
+	       port->base + PCIE_CFG_HEADER0);
+	writel(CFG_HEADER_DW1(where, size), port->base + PCIE_CFG_HEADER1);
+	writel(CFG_HEADER_DW2(where, PCI_FUNC(devfn), PCI_DEV(devfn), bus),
+	       port->base + PCIE_CFG_HEADER2);
+
+	/* Write Cfgwr data */
+	val = val << 8 * (where & 3);
+	writel(val, port->base + PCIE_CFG_WDATA);
+
+	/* Trigger h/w to transmit Cfgwr TLP */
+	val = readl(port->base + PCIE_APP_TLP_REQ);
+	val |= APP_CFG_REQ;
+	writel(val, port->base + PCIE_APP_TLP_REQ);
+
+	/* Check completion status */
+	return mtk_pcie_check_cfg_cpld(port);
+}
+
+static struct mtk_pcie_port *mtk_pcie_find_port(const struct udevice *bus,
+						pci_dev_t bdf)
+{
+	struct mtk_pcie *pcie = dev_get_priv(bus);
+	struct mtk_pcie_port *port;
+	struct udevice *dev;
+	struct pci_child_platdata *pplat = NULL;
+	int ret = 0;
+
+	if (PCI_BUS(bdf) != 0) {
+		ret = pci_get_bus(PCI_BUS(bdf), &dev);
+		if (ret) {
+			debug("No such device,ret = %d\n", ret);
+			return NULL;
+		}
+
+		while (dev->parent->seq != 0)
+			dev = dev->parent;
+
+		pplat = dev_get_parent_platdata(dev);
+	}
+
+	list_for_each_entry(port, &pcie->ports, list) {
+		if ((PCI_BUS(bdf) == 0) && (PCI_DEV(bdf) == port->slot))
+			return port;
+
+		if (PCI_BUS(bdf) != 0 && PCI_DEV(bdf) == 0 &&
+		    PCI_DEV(pplat->devfn) == port->slot)
+			return port;
+	}
+
+	return NULL;
+}
+
+static int mtk_pcie_config_read(const struct udevice *bus, pci_dev_t bdf,
+				uint offset, ulong *valuep,
+				enum pci_size_t size)
+{
+	struct mtk_pcie_port *port;
+	int ret;
+
+	port = mtk_pcie_find_port(bus, bdf);
+	if (!port) {
+		*valuep = pci_get_ff(size);
+		return 0;
+	}
+
+	ret = mtk_pcie_hw_rd_cfg(port, PCI_BUS(bdf), bdf, offset, (1 << size), valuep);
+	if (ret)
+		*valuep = pci_get_ff(size);
+
+	return ret;
+}
+
+static int mtk_pcie_config_write(struct udevice *bus, pci_dev_t bdf,
+				 uint offset, ulong value,
+				 enum pci_size_t size)
+{
+	struct mtk_pcie_port *port;
+
+	port = mtk_pcie_find_port(bus, bdf);
+	if (!port)
+		return 0;
+
+	/* Do not modify RC bar 0/1. */
+	if (PCI_BUS(bdf) == 0 && (offset == 0x10 || offset == 0x14))
+		return 0;
+
+	return mtk_pcie_hw_wr_cfg(port, PCI_BUS(bdf), bdf, offset, (1 << size), value);
+}
+
+static const struct dm_pci_ops mtk_pcie_ops_v2 = {
+	.read_config  = mtk_pcie_config_read,
+	.write_config = mtk_pcie_config_write,
+};
+
 static void mtk_pcie_port_free(struct mtk_pcie_port *port)
 {
 	list_del(&port->list);
@@ -151,6 +370,73 @@ static int mtk_pcie_startup_port(struct mtk_pcie_port *port)
 	return 0;
 }
 
+static int mtk_pcie_startup_port_v2(struct mtk_pcie_port *port)
+{
+	struct mtk_pcie *pcie = port->pcie;
+	struct udevice *dev = pcie->priv;
+	struct pci_region *pci_mem;
+	u32 val;
+	int err;
+
+	/* MT7622/MT7629 platforms need to enable LTSSM and ASPM from PCIe subsys */
+	if (pcie->base) {
+		val = readl(pcie->base + PCIE_SYS_CFG_V2);
+		val |= PCIE_CSR_LTSSM_EN(port->slot) |
+		       PCIE_CSR_ASPM_L1_EN(port->slot);
+		writel(val, pcie->base + PCIE_SYS_CFG_V2);
+	}
+
+	/* Assert all reset signals */
+	writel(0, port->base + PCIE_RST_CTRL);
+
+	/*
+	 * Enable PCIe link down reset, if link status changed from link up to
+	 * link down, this will reset MAC control registers and configuration
+	 * space.
+	 */
+	writel(PCIE_LINKDOWN_RST_EN, port->base + PCIE_RST_CTRL);
+	udelay(500);
+
+	/* De-assert PHY, PE, PIPE, MAC and configuration reset	*/
+	val = readl(port->base + PCIE_RST_CTRL);
+	val |= PCIE_PHY_RSTB | PCIE_PIPE_SRSTB | PCIE_MAC_SRSTB | PCIE_CRSTB;
+	writel(val, port->base + PCIE_RST_CTRL);
+
+	mdelay(100);
+	val |= PCIE_PERSTB;
+	writel(val, port->base + PCIE_RST_CTRL);
+
+	/* Set up vendor ID and class code */
+	val = PCI_VENDOR_ID_MEDIATEK;
+	writew(val, port->base + PCIE_CONF_VEND_ID);
+
+	val = PCI_CLASS_BRIDGE_PCI;
+	writew(val, port->base + PCIE_CONF_CLASS_ID);
+
+	/* 100ms timeout value should be enough for Gen1/2 training */
+	err = readl_poll_timeout(port->base + PCIE_LINK_STATUS_V2, val,
+				 !!(val & PCIE_PORT_LINKUP_V2),
+				 100 * 1000);
+	if (err)
+		return -ETIMEDOUT;
+
+	pci_get_regions(dev, NULL, &pci_mem, NULL);
+
+	/* Set AHB to PCIe translation windows */
+	val = lower_32_bits(pci_mem->bus_start) |
+	      AHB2PCIE_SIZE(fls(pci_mem->size) - 1);
+	writel(val, port->base + PCIE_AHB_TRANS_BASE0_L);
+
+	val = upper_32_bits(pci_mem->bus_start);
+	writel(val, port->base + PCIE_AHB_TRANS_BASE0_H);
+
+	/* Set PCIe to AXI translation memory space.*/
+	val = PCIE2AHB_SIZE | WIN_ENABLE;
+	writel(val, port->base + PCIE_AXI_WINDOW0);
+
+	return 0;
+}
+
 static void mtk_pcie_enable_port(struct mtk_pcie_port *port)
 {
 	int err;
@@ -183,6 +469,55 @@ exit:
 	mtk_pcie_port_free(port);
 }
 
+static void mtk_pcie_enable_port_v2(struct mtk_pcie_port *port)
+{
+	int err = 0;
+
+	err = clk_enable(&port->sys_ck);
+	if (err) {
+		debug("clk_enable(sys_ck) failed: %d\n", err);
+		goto exit;
+	}
+
+	err = clk_enable(&port->ahb_ck);
+	if (err) {
+		debug("clk_enable(ahb_ck) failed: %d\n", err);
+		goto exit;
+	}
+
+	err = clk_enable(&port->aux_ck);
+	if (err) {
+		debug("clk_enable(aux_ck) failed: %d\n", err);
+		goto exit;
+	}
+
+	err = clk_enable(&port->axi_ck);
+	if (err) {
+		debug("clk_enable(axi_ck) failed: %d\n", err);
+		goto exit;
+	}
+
+	err = clk_enable(&port->obff_ck);
+	if (err) {
+		debug("clk_enable(obff_ck) failed: %d\n", err);
+		goto exit;
+	}
+
+	err = clk_enable(&port->pipe_ck);
+	if (err) {
+		debug("clk_enable(pipe_ck) failed: %d\n", err);
+		goto exit;
+	}
+
+	err = mtk_pcie_startup_port_v2(port);
+	if (!err)
+		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);
@@ -221,6 +556,75 @@ static int mtk_pcie_parse_port(struct udevice *dev, u32 slot)
 	return 0;
 }
 
+static int mtk_pcie_parse_port_v2(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) {
+		debug("failed to map port%d base\n", slot);
+		return -ENOENT;
+	}
+
+	snprintf(name, sizeof(name), "sys_ck%d", slot);
+	err = clk_get_by_name(dev, name, &port->sys_ck);
+	if (err) {
+		debug("clk_get_by_name(sys_ck) failed: %d\n", err);
+		return err;
+	}
+
+	snprintf(name, sizeof(name), "ahb_ck%d", slot);
+	err = clk_get_by_name(dev, name, &port->ahb_ck);
+	if (err) {
+		debug("clk_get_by_name(ahb_ck) failed: %d\n", err);
+		return err;
+	}
+
+	snprintf(name, sizeof(name), "aux_ck%d", slot);
+	err = clk_get_by_name(dev, name, &port->aux_ck);
+	if (err) {
+		debug("clk_get_by_name(aux_ck) failed: %d\n", err);
+		return err;
+	}
+
+	snprintf(name, sizeof(name), "axi_ck%d", slot);
+	err = clk_get_by_name(dev, name, &port->axi_ck);
+	if (err) {
+		debug("clk_get_by_name(axi_ck) failed: %d\n", err);
+		return err;
+	}
+
+	snprintf(name, sizeof(name), "obff_ck%d", slot);
+	err = clk_get_by_name(dev, name, &port->obff_ck);
+	if (err) {
+		debug("clk_get_by_name(obff_ck) failed: %d\n", err);
+		return err;
+	}
+
+	snprintf(name, sizeof(name), "pipe_ck%d", slot);
+	err = clk_get_by_name(dev, name, &port->pipe_ck);
+	if (err) {
+		debug("clk_get_by_name(pipe_ck) failed: %d\n", 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);
@@ -268,16 +672,68 @@ static int mtk_pcie_probe(struct udevice *dev)
 	return 0;
 }
 
+static int mtk_pcie_probe_v2(struct udevice *dev)
+{
+	struct mtk_pcie *pcie = dev_get_priv(dev);
+	struct mtk_pcie_port *port, *tmp;
+	struct fdt_pci_addr addr;
+	ofnode subnode;
+	unsigned int slot;
+	int err;
+
+	INIT_LIST_HEAD(&pcie->ports);
+
+	pcie->base = dev_remap_addr_name(dev, "subsys");
+	if (!pcie->base)
+		return -ENOENT;
+
+	pcie->priv = dev;
+
+	dev_for_each_subnode(subnode, dev) {
+		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_v2(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_v2(port);
+
+	return 0;
+}
+
 static const struct udevice_id mtk_pcie_ids[] = {
-	{ .compatible = "mediatek,mt7623-pcie", },
+	{ .compatible = "mediatek,mt7623-pcie", PCIE_V1},
 	{ }
 };
 
-U_BOOT_DRIVER(pcie_mediatek) = {
-	.name	= "pcie_mediatek",
+U_BOOT_DRIVER(pcie_mediatek_v1) = {
+	.name	= "pcie_mediatek_v1",
 	.id	= UCLASS_PCI,
 	.of_match = mtk_pcie_ids,
 	.ops	= &mtk_pcie_ops,
 	.probe	= mtk_pcie_probe,
 	.priv_auto_alloc_size = sizeof(struct mtk_pcie),
 };
+
+static const struct udevice_id mtk_pcie_ids_v2[] = {
+	{ .compatible = "mediatek,mt7622-pcie", PCIE_V2},
+	{ }
+};
+
+U_BOOT_DRIVER(pcie_mediatek_v2) = {
+	.name	= "pcie_mediatek_v2",
+	.id	= UCLASS_PCI,
+	.of_match = mtk_pcie_ids_v2,
+	.ops	= &mtk_pcie_ops_v2,
+	.probe	= mtk_pcie_probe_v2,
+	.priv_auto_alloc_size = sizeof(struct mtk_pcie),
+};