[PATCH 02/11] pci: mediatek: add PCIe controller support for filogic silicon

[Christian Marangi <ansuelsmth@gmail.com>]

From: John Crispin <john@phrozen.org>

Add MediaTek GEN3 PCIe controller support for filogic silicon.
This is adapted from the Linux version of the driver.

Signed-off-by: John Crispin <john@phrozen.org>
[ fix minor problems, fix checkpatch errors ]
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
---
 drivers/pci/Kconfig              |   7 +
 drivers/pci/Makefile             |   1 +
 drivers/pci/pcie_mediatek_gen3.c | 382 +++++++++++++++++++++++++++++++
 3 files changed, 390 insertions(+)
 create mode 100644 drivers/pci/pcie_mediatek_gen3.c

diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig
index 8d02ab82ad9..22a56f4ca38 100644
--- a/drivers/pci/Kconfig
+++ b/drivers/pci/Kconfig
@@ -350,6 +350,13 @@ config PCIE_MEDIATEK
 	  Say Y here if you want to enable Gen2 PCIe controller,
 	  which could be found on MT7623 SoC family.
 
+config PCIE_MEDIATEK_GEN3
+	bool "MediaTek PCIe Gen3 controller"
+	depends on ARCH_MEDIATEK
+	help
+	  Say Y here if you want to enable Gen3 PCIe controller,
+	  which could be found on the Mediatek Filogic SoC family.
+
 config PCIE_DW_MESON
 	bool "Amlogic Meson DesignWare based PCIe controller"
 	depends on ARCH_MESON
diff --git a/drivers/pci/Makefile b/drivers/pci/Makefile
index 2927c519129..5b2d2969802 100644
--- a/drivers/pci/Makefile
+++ b/drivers/pci/Makefile
@@ -42,6 +42,7 @@ obj-$(CONFIG_PCIE_INTEL_FPGA) += pcie_intel_fpga.o
 obj-$(CONFIG_PCIE_DW_COMMON) += pcie_dw_common.o
 obj-$(CONFIG_PCI_KEYSTONE) += pcie_dw_ti.o
 obj-$(CONFIG_PCIE_MEDIATEK) += pcie_mediatek.o
+obj-$(CONFIG_PCIE_MEDIATEK_GEN3) += pcie_mediatek_gen3.o
 obj-$(CONFIG_PCIE_ROCKCHIP) += pcie_rockchip.o
 obj-$(CONFIG_PCIE_DW_ROCKCHIP) += pcie_dw_rockchip.o
 obj-$(CONFIG_PCIE_DW_MESON) += pcie_dw_meson.o
diff --git a/drivers/pci/pcie_mediatek_gen3.c b/drivers/pci/pcie_mediatek_gen3.c
new file mode 100644
index 00000000000..673813b8b75
--- /dev/null
+++ b/drivers/pci/pcie_mediatek_gen3.c
@@ -0,0 +1,382 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * MediaTek PCIe host controller driver.
+ *
+ * Copyright (c) 2023 John Crispin <john@phrozen.org>
+ * Driver is based on u-boot gen1/2 and upstream linux gen3 code
+ */
+
+#include <clk.h>
+#include <dm.h>
+#include <generic-phy.h>
+#include <log.h>
+#include <malloc.h>
+#include <pci.h>
+#include <reset.h>
+#include <asm/io.h>
+#include <dm/device_compat.h>
+#include <dm/devres.h>
+#include <linux/bitops.h>
+#include <linux/iopoll.h>
+#include <linux/list.h>
+#include "pci_internal.h"
+
+/* PCIe shared registers */
+#define PCIE_CFG_ADDR			0x20
+#define PCIE_CFG_DATA			0x24
+
+#define PCIE_SETTING_REG		0x80
+
+#define PCIE_PCI_IDS_1			0x9c
+#define PCIE_RC_MODE			BIT(0)
+#define PCI_CLASS(class)		((class) << 8)
+
+#define PCIE_CFGNUM_REG			0x140
+#define PCIE_CFG_DEVFN(devfn)		((devfn) & GENMASK(7, 0))
+#define PCIE_CFG_BUS(bus)		(((bus) << 8) & GENMASK(15, 8))
+#define PCIE_CFG_BYTE_EN(bytes)		(((bytes) << 16) & GENMASK(19, 16))
+#define PCIE_CFG_FORCE_BYTE_EN		BIT(20)
+#define PCIE_CFG_OFFSET_ADDR		0x1000
+#define PCIE_CFG_HEADER(bus, devfn)	(PCIE_CFG_BUS(bus) | PCIE_CFG_DEVFN(devfn))
+
+#define PCIE_RST_CTRL_REG		0x148
+#define PCIE_MAC_RSTB			BIT(0)
+#define PCIE_PHY_RSTB			BIT(1)
+#define PCIE_BRG_RSTB			BIT(2)
+#define PCIE_PE_RSTB			BIT(3)
+
+#define PCIE_LINK_STATUS_REG		0x154
+#define PCIE_PORT_LINKUP		BIT(8)
+
+#define PCIE_INT_ENABLE_REG		0x180
+
+#define PCIE_MISC_CTRL_REG		0x348
+#define PCIE_DISABLE_DVFSRC_VLT_REQ	BIT(1)
+
+#define PCIE_TRANS_TABLE_BASE_REG       0x800
+#define PCIE_ATR_SRC_ADDR_MSB_OFFSET    0x4
+#define PCIE_ATR_TRSL_ADDR_LSB_OFFSET   0x8
+#define PCIE_ATR_TRSL_ADDR_MSB_OFFSET   0xc
+#define PCIE_ATR_TRSL_PARAM_OFFSET      0x10
+#define PCIE_ATR_TLB_SET_OFFSET         0x20
+
+#define PCIE_MAX_TRANS_TABLES           8
+#define PCIE_ATR_EN                     BIT(0)
+#define PCIE_ATR_SIZE(size) \
+	(((((size) - 1) << 1) & GENMASK(6, 1)) | PCIE_ATR_EN)
+#define PCIE_ATR_ID(id)                 ((id) & GENMASK(3, 0))
+#define PCIE_ATR_TYPE_MEM               PCIE_ATR_ID(0)
+#define PCIE_ATR_TYPE_IO                PCIE_ATR_ID(1)
+#define PCIE_ATR_TLP_TYPE(type)         (((type) << 16) & GENMASK(18, 16))
+#define PCIE_ATR_TLP_TYPE_MEM           PCIE_ATR_TLP_TYPE(0)
+#define PCIE_ATR_TLP_TYPE_IO            PCIE_ATR_TLP_TYPE(2)
+
+struct mtk_pcie {
+	void __iomem *base;
+	void *priv;
+	struct clk pl_250m_ck;
+	struct clk tl_26m_ck;
+	struct clk peri_26m_ck;
+	struct clk top_133m_ck;
+	struct reset_ctl reset_phy;
+	struct reset_ctl reset_mac;
+	struct phy phy;
+};
+
+static void mtk_pcie_config_tlp_header(const struct udevice *bus,
+				       pci_dev_t devfn,
+				       int where, int size)
+{
+	struct mtk_pcie *pcie = dev_get_priv(bus);
+	int bytes;
+	u32 val;
+
+	size = 1 << size;
+	bytes = (GENMASK(size - 1, 0) & 0xf) << (where & 0x3);
+
+	val = PCIE_CFG_FORCE_BYTE_EN | PCIE_CFG_BYTE_EN(bytes) |
+	      PCIE_CFG_HEADER(PCI_BUS(devfn), (devfn >> 8));
+
+	writel(val, pcie->base + PCIE_CFGNUM_REG);
+}
+
+static int mtk_pcie_config_address(const struct udevice *udev, pci_dev_t bdf,
+				   uint offset, void **paddress)
+{
+	struct mtk_pcie *pcie = dev_get_priv(udev);
+
+	*paddress = pcie->base + PCIE_CFG_OFFSET_ADDR + offset;
+
+	return 0;
+}
+
+static int mtk_pcie_read_config(const struct udevice *bus, pci_dev_t bdf,
+				uint offset, ulong *valuep,
+				enum pci_size_t size)
+{
+	int ret;
+
+	mtk_pcie_config_tlp_header(bus, bdf, offset, size);
+	ret = pci_generic_mmap_read_config(bus, mtk_pcie_config_address,
+					   bdf, offset, valuep, size);
+	return ret;
+}
+
+static int mtk_pcie_write_config(struct udevice *bus, pci_dev_t bdf,
+				 uint offset, ulong value,
+				 enum pci_size_t size)
+{
+	mtk_pcie_config_tlp_header(bus, bdf, offset, size);
+
+	switch (size) {
+	case PCI_SIZE_8:
+	case PCI_SIZE_16:
+		value <<= (offset & 0x3) * 8;
+	case PCI_SIZE_32:
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return pci_generic_mmap_write_config(bus, mtk_pcie_config_address,
+					     bdf, (offset & ~0x3), value, PCI_SIZE_32);
+}
+
+static const struct dm_pci_ops mtk_pcie_ops = {
+	.read_config	= mtk_pcie_read_config,
+	.write_config	= mtk_pcie_write_config,
+};
+
+static int mtk_pcie_set_trans_table(struct udevice *dev, struct mtk_pcie *pcie,
+				    u64 cpu_addr, u64 pci_addr, u64 size,
+				    unsigned long type, int num)
+{
+	void __iomem *table;
+	u32 val;
+
+	if (num >= PCIE_MAX_TRANS_TABLES) {
+		dev_err(dev, "not enough translate table for addr: %#llx, limited to [%d]\n",
+			(unsigned long long)cpu_addr, PCIE_MAX_TRANS_TABLES);
+		return -ENODEV;
+	}
+
+	dev_dbg(dev, "set trans table %d: %#llx %#llx, %#llx\n", num, cpu_addr,
+		pci_addr, size);
+	table = pcie->base + PCIE_TRANS_TABLE_BASE_REG +
+		num * PCIE_ATR_TLB_SET_OFFSET;
+
+	writel(lower_32_bits(cpu_addr) | PCIE_ATR_SIZE(fls(size) - 1), table);
+	writel(upper_32_bits(cpu_addr), table + PCIE_ATR_SRC_ADDR_MSB_OFFSET);
+	writel(lower_32_bits(pci_addr), table + PCIE_ATR_TRSL_ADDR_LSB_OFFSET);
+	writel(upper_32_bits(pci_addr), table + PCIE_ATR_TRSL_ADDR_MSB_OFFSET);
+
+	if (type == PCI_REGION_IO)
+		val = PCIE_ATR_TYPE_IO | PCIE_ATR_TLP_TYPE_IO;
+	else
+		val = PCIE_ATR_TYPE_MEM | PCIE_ATR_TLP_TYPE_MEM;
+	writel(val, table + PCIE_ATR_TRSL_PARAM_OFFSET);
+
+	return 0;
+}
+
+static int mtk_pcie_startup_port(struct udevice *dev)
+{
+	struct mtk_pcie *pcie = dev_get_priv(dev);
+	struct udevice *ctlr = pci_get_controller(dev);
+	struct pci_controller *hose = dev_get_uclass_priv(ctlr);
+	u32 val;
+	int i, err;
+
+	/* Set as RC mode */
+	val = readl(pcie->base + PCIE_SETTING_REG);
+	val |= PCIE_RC_MODE;
+	writel(val, pcie->base + PCIE_SETTING_REG);
+
+	/* setup RC BARs */
+	writel(PCI_BASE_ADDRESS_MEM_TYPE_64,
+	       pcie->base + PCI_BASE_ADDRESS_0);
+	writel(0x0, pcie->base + PCI_BASE_ADDRESS_1);
+
+	/* setup interrupt pins */
+	clrsetbits_le32(pcie->base + PCI_INTERRUPT_LINE,
+			0xff00, 0x100);
+
+	/* setup bus numbers */
+	clrsetbits_le32(pcie->base + PCI_PRIMARY_BUS,
+			0xffffff, 0x00ff0100);
+
+	/* setup command register */
+	clrsetbits_le32(pcie->base + PCI_PRIMARY_BUS,
+			0xffff,
+			PCI_COMMAND_IO | PCI_COMMAND_MEMORY |
+			PCI_COMMAND_MASTER | PCI_COMMAND_SERR);
+
+	/* Set class code */
+	val = readl(pcie->base + PCIE_PCI_IDS_1);
+	val &= ~GENMASK(31, 8);
+	val |= PCI_CLASS(PCI_CLASS_BRIDGE_PCI << 8);
+	writel(val, pcie->base + PCIE_PCI_IDS_1);
+
+	/* Mask all INTx interrupts */
+	val = readl(pcie->base + PCIE_INT_ENABLE_REG);
+	val &= ~0xFF000000;
+	writel(val, pcie->base + PCIE_INT_ENABLE_REG);
+
+	/* Disable DVFSRC voltage request */
+	val = readl(pcie->base + PCIE_MISC_CTRL_REG);
+	val |= PCIE_DISABLE_DVFSRC_VLT_REQ;
+	writel(val, pcie->base + PCIE_MISC_CTRL_REG);
+
+	/* Assert all reset signals */
+	val = readl(pcie->base + PCIE_RST_CTRL_REG);
+	val |= PCIE_MAC_RSTB | PCIE_PHY_RSTB | PCIE_BRG_RSTB | PCIE_PE_RSTB;
+	writel(val, pcie->base + PCIE_RST_CTRL_REG);
+
+	/*
+	 * Described in PCIe CEM specification sections 2.2 (PERST# Signal)
+	 * and 2.2.1 (Initial Power-Up (G3 to S0)).
+	 * The deassertion of PERST# should be delayed 100ms (TPVPERL)
+	 * for the power and clock to become stable.
+	 */
+	mdelay(100);
+
+	/* De-assert reset signals */
+	val &= ~(PCIE_MAC_RSTB | PCIE_PHY_RSTB | PCIE_BRG_RSTB);
+	writel(val, pcie->base + PCIE_RST_CTRL_REG);
+
+	mdelay(100);
+
+	/* De-assert PERST# signals */
+	val &= ~(PCIE_PE_RSTB);
+	writel(val, pcie->base + PCIE_RST_CTRL_REG);
+
+	/* 100ms timeout value should be enough for Gen1/2 training */
+	err = readl_poll_timeout(pcie->base + PCIE_LINK_STATUS_REG, val,
+				 !!(val & PCIE_PORT_LINKUP),
+				 100 * 1000);
+	if (err) {
+		dev_dbg(dev, "no card detected\n");
+		return -ETIMEDOUT;
+	}
+	dev_dbg(dev, "detected a card\n");
+
+	for (i = 0; i < hose->region_count; i++) {
+		struct pci_region *reg = &hose->regions[i];
+
+		if (reg->flags != PCI_REGION_MEM)
+			continue;
+
+		mtk_pcie_set_trans_table(dev, pcie, reg->bus_start, reg->phys_start,
+					 reg->size, reg->flags, 0);
+	}
+
+	return 0;
+}
+
+static int mtk_pcie_power_on(struct udevice *dev)
+{
+	struct mtk_pcie *pcie = dev_get_priv(dev);
+	int err;
+
+	pcie->base = dev_remap_addr_name(dev, "pcie-mac");
+	if (!pcie->base)
+		return -ENOENT;
+
+	pcie->priv = dev;
+
+	err = generic_phy_get_by_name(dev, "pcie-phy", &pcie->phy);
+	if (err)
+		return err;
+
+	/*
+	 * Upstream linux kernel devine these clock without clock-names
+	 * and use clk bulk API to enable them all.
+	 */
+	err = clk_get_by_index(dev, 0, &pcie->pl_250m_ck);
+	if (err)
+		return err;
+
+	err = clk_get_by_index(dev, 1, &pcie->tl_26m_ck);
+	if (err)
+		return err;
+
+	err = clk_get_by_index(dev, 2, &pcie->peri_26m_ck);
+	if (err)
+		return err;
+
+	err = clk_get_by_index(dev, 3, &pcie->top_133m_ck);
+	if (err)
+		return err;
+
+	err = generic_phy_init(&pcie->phy);
+	if (err)
+		return err;
+
+	err = generic_phy_power_on(&pcie->phy);
+	if (err)
+		goto err_phy_on;
+
+	err = clk_enable(&pcie->pl_250m_ck);
+	if (err)
+		goto err_clk_pl_250m;
+
+	err = clk_enable(&pcie->tl_26m_ck);
+	if (err)
+		goto err_clk_tl_26m;
+
+	err = clk_enable(&pcie->peri_26m_ck);
+	if (err)
+		goto err_clk_peri_26m;
+
+	err = clk_enable(&pcie->top_133m_ck);
+	if (err)
+		goto err_clk_top_133m;
+
+	err = mtk_pcie_startup_port(dev);
+	if (err)
+		goto err_startup;
+
+	return 0;
+
+err_startup:
+err_clk_top_133m:
+	clk_disable(&pcie->top_133m_ck);
+err_clk_peri_26m:
+	clk_disable(&pcie->peri_26m_ck);
+err_clk_tl_26m:
+	clk_disable(&pcie->tl_26m_ck);
+err_clk_pl_250m:
+	clk_disable(&pcie->pl_250m_ck);
+err_phy_on:
+	generic_phy_exit(&pcie->phy);
+
+	return err;
+}
+
+static int mtk_pcie_probe(struct udevice *dev)
+{
+	struct mtk_pcie *pcie = dev_get_priv(dev);
+	int err;
+
+	pcie->priv = dev;
+
+	err = mtk_pcie_power_on(dev);
+	if (err)
+		return err;
+
+	return 0;
+}
+
+static const struct udevice_id mtk_pcie_ids[] = {
+	{ .compatible = "mediatek,mt8192-pcie" },
+	{ }
+};
+
+U_BOOT_DRIVER(pcie_mediatek_gen3) = {
+	.name		= "pcie_mediatek_gen3",
+	.id		= UCLASS_PCI,
+	.of_match	= mtk_pcie_ids,
+	.ops		= &mtk_pcie_ops,
+	.probe		= mtk_pcie_probe,
+	.priv_auto	= sizeof(struct mtk_pcie),
+};
-- 
2.43.0