[PATCH v4 1/3] starfive: pci: Add StarFive JH7110 pcie driver

[Minda Chen <minda.chen@starfivetech.com>]

From: Mason Huo <mason.huo@starfivetech.com>

Add pcie driver for StarFive JH7110, the driver depends on
starfive gpio, pinctrl, clk and reset driver to do init.

Several devices are tested:
a) M.2 NVMe SSD
b) Realtek 8169 Ethernet adapter.

Signed-off-by: Mason Huo <mason.huo@starfivetech.com>
Signed-off-by: Minda Chen <minda.chen@starfivetech.com>
---
 drivers/pci/Kconfig                |   9 +
 drivers/pci/Makefile               |   1 +
 drivers/pci/pcie_starfive_jh7110.c | 465 +++++++++++++++++++++++++++++
 3 files changed, 475 insertions(+)
 create mode 100644 drivers/pci/pcie_starfive_jh7110.c

diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig
index ef328d2652..f37b6baa25 100644
--- a/drivers/pci/Kconfig
+++ b/drivers/pci/Kconfig
@@ -374,4 +374,13 @@ config PCIE_UNIPHIER
 	  Say Y here if you want to enable PCIe controller support on
 	  UniPhier SoCs.
 
+config PCIE_STARFIVE_JH7110
+	bool "Enable Starfive JH7110 PCIe driver"
+	imply STARFIVE_JH7110
+	imply CLK_JH7110
+	imply RESET_JH7110
+	help
+	  Say Y here if you want to enable PCIe controller support on
+	  StarFive JH7110 SoC.
+
 endif
diff --git a/drivers/pci/Makefile b/drivers/pci/Makefile
index 49506e7ba5..bbe3323bb5 100644
--- a/drivers/pci/Makefile
+++ b/drivers/pci/Makefile
@@ -49,3 +49,4 @@ obj-$(CONFIG_PCI_OCTEONTX) += pci_octeontx.o
 obj-$(CONFIG_PCIE_OCTEON) += pcie_octeon.o
 obj-$(CONFIG_PCIE_DW_SIFIVE) += pcie_dw_sifive.o
 obj-$(CONFIG_PCIE_UNIPHIER) += pcie_uniphier.o
+obj-$(CONFIG_PCIE_STARFIVE_JH7110) += pcie_starfive_jh7110.o
diff --git a/drivers/pci/pcie_starfive_jh7110.c b/drivers/pci/pcie_starfive_jh7110.c
new file mode 100644
index 0000000000..130181013e
--- /dev/null
+++ b/drivers/pci/pcie_starfive_jh7110.c
@@ -0,0 +1,465 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * StarFive PLDA PCIe host controller driver
+ *
+ * Copyright (c) 2023 Starfive, Inc.
+ * Author: Mason Huo <mason.huo@starfivetech.com>
+ *
+ */
+
+#include <common.h>
+#include <clk.h>
+#include <dm.h>
+#include <generic-phy.h>
+#include <pci.h>
+#include <pci_ids.h>
+#include <power-domain.h>
+#include <regmap.h>
+#include <reset.h>
+#include <syscon.h>
+#include <asm/global_data.h>
+#include <asm/io.h>
+#include <asm-generic/gpio.h>
+#include <dm/device_compat.h>
+#include <dm/pinctrl.h>
+#include <linux/delay.h>
+#include <linux/iopoll.h>
+#include <power/regulator.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+#define GEN_SETTINGS			0x80
+#define PCIE_PCI_IDS			0x9C
+#define PCIE_WINROM			0xFC
+#define PMSG_SUPPORT_RX			0x3F0
+#define PCI_MISC			0xB4
+
+#define PLDA_EP_ENABLE			0
+#define PLDA_RP_ENABLE			1
+
+#define IDS_CLASS_CODE_SHIFT		8
+
+#define PREF_MEM_WIN_64_SUPPORT		BIT(3)
+#define PMSG_LTR_SUPPORT		BIT(2)
+#define PLDA_FUNCTION_DIS		BIT(15)
+#define PLDA_FUNC_NUM			4
+#define PLDA_PHY_FUNC_SHIFT		9
+
+#define XR3PCI_ATR_AXI4_SLV0		0x800
+#define XR3PCI_ATR_SRC_ADDR_LOW		0x0
+#define XR3PCI_ATR_SRC_ADDR_HIGH	0x4
+#define XR3PCI_ATR_TRSL_ADDR_LOW	0x8
+#define XR3PCI_ATR_TRSL_ADDR_HIGH	0xc
+#define XR3PCI_ATR_TRSL_PARAM		0x10
+#define XR3PCI_ATR_TABLE_OFFSET		0x20
+#define XR3PCI_ATR_MAX_TABLE_NUM	8
+
+#define XR3PCI_ATR_SRC_WIN_SIZE_SHIFT	1
+#define XR3PCI_ATR_SRC_ADDR_MASK	GENMASK(31, 12)
+#define XR3PCI_ATR_TRSL_ADDR_MASK	GENMASK(31, 12)
+#define XR3_PCI_ECAM_SIZE		28
+#define XR3PCI_ATR_TRSL_DIR		BIT(22)
+/* IDs used in the XR3PCI_ATR_TRSL_PARAM */
+#define XR3PCI_ATR_TRSLID_PCIE_MEMORY	0x0
+#define XR3PCI_ATR_TRSLID_PCIE_CONFIG	0x1
+
+/* system control */
+#define STG_SYSCON_K_RP_NEP_MASK		BIT(8)
+#define STG_SYSCON_AXI4_SLVL_ARFUNC_MASK	GENMASK(22, 8)
+#define STG_SYSCON_AXI4_SLVL_ARFUNC_SHIFT	8
+#define STG_SYSCON_AXI4_SLVL_AWFUNC_MASK	GENMASK(14, 0)
+#define STG_SYSCON_CLKREQ_MASK			BIT(22)
+#define STG_SYSCON_CKREF_SRC_SHIFT		18
+#define STG_SYSCON_CKREF_SRC_MASK		GENMASK(19, 18)
+
+struct starfive_pcie {
+	struct udevice *dev;
+
+	void __iomem *reg_base;
+	void __iomem *cfg_base;
+
+	struct regmap *regmap;
+	u32 stg_arfun;
+	u32 stg_awfun;
+	u32 stg_rp_nep;
+
+	struct clk_bulk	clks;
+	struct reset_ctl_bulk	rsts;
+	struct gpio_desc	reset_gpio;
+
+	int atr_table_num;
+	int sec_busno;
+};
+
+static bool starfive_pcie_addr_valid(pci_dev_t bdf, struct starfive_pcie *priv)
+{
+	/*
+	 * Single device limitation.
+	 * For JH7110 SoC limitation, one bus can only connnect one device.
+	 * And PCIe controller contain HW issue that secondary bus of
+	 * host bridge emumerate duplicate devices.
+	 * Only can access device 0 in secondary bus.
+	 */
+	if (PCI_BUS(bdf) == priv->sec_busno && PCI_DEV(bdf) > 0)
+		return false;
+
+	return true;
+}
+
+static int starfive_pcie_conf_address(const struct udevice *udev, pci_dev_t bdf,
+				      uint offset, void **paddr)
+{
+	struct starfive_pcie *priv = dev_get_priv(udev);
+	int where = PCIE_ECAM_OFFSET(PCI_BUS(bdf), PCI_DEV(bdf),
+				     PCI_FUNC(bdf), offset);
+
+	if (!starfive_pcie_addr_valid(bdf, priv))
+		return -ENODEV;
+
+	*paddr = (void *)(priv->cfg_base + where);
+	return 0;
+}
+
+static int starfive_pcie_config_read(const struct udevice *udev, pci_dev_t bdf,
+				     uint offset, ulong *valuep,
+				     enum pci_size_t size)
+{
+	return pci_generic_mmap_read_config(udev, starfive_pcie_conf_address,
+					    bdf, offset, valuep, size);
+}
+
+int starfive_pcie_config_write(struct udevice *udev, pci_dev_t bdf,
+			       uint offset, ulong value,
+			       enum pci_size_t size)
+{
+	struct starfive_pcie *priv = dev_get_priv(udev);
+	int ret;
+
+	ret = pci_generic_mmap_write_config(udev, starfive_pcie_conf_address,
+					    bdf, offset, value, size);
+
+	if (!ret && offset == PCI_SECONDARY_BUS) {
+		priv->sec_busno = value & 0xff;
+		debug("Secondary bus number was changed to %d\n",
+		      priv->sec_busno);
+	}
+	return ret;
+}
+
+static int starfive_pcie_set_atr_entry(struct starfive_pcie *priv, phys_addr_t src_addr,
+				       phys_addr_t trsl_addr, size_t window_size,
+				       int trsl_param)
+{
+	void __iomem *base =
+		priv->reg_base + XR3PCI_ATR_AXI4_SLV0;
+
+	/* Support AXI4 Slave 0 Address Translation Tables 0-7. */
+	if (priv->atr_table_num >= XR3PCI_ATR_MAX_TABLE_NUM) {
+		dev_err(priv->dev, "ATR table number %d exceeds max num\n",
+			priv->atr_table_num);
+		return -EINVAL;
+	}
+	base +=  XR3PCI_ATR_TABLE_OFFSET * priv->atr_table_num;
+	priv->atr_table_num++;
+
+	/*
+	 * X3PCI_ATR_SRC_ADDR_LOW:
+	 *   - bit 0: enable entry,
+	 *   - bits 1-6: ATR window size: total size in bytes: 2^(ATR_WSIZE + 1)
+	 *   - bits 7-11: reserved
+	 *   - bits 12-31: start of source address
+	 */
+	writel((lower_32_bits(src_addr) & XR3PCI_ATR_SRC_ADDR_MASK) |
+			(fls(window_size) - 1) << XR3PCI_ATR_SRC_WIN_SIZE_SHIFT | 1,
+			base + XR3PCI_ATR_SRC_ADDR_LOW);
+	writel(upper_32_bits(src_addr), base + XR3PCI_ATR_SRC_ADDR_HIGH);
+	writel((lower_32_bits(trsl_addr) & XR3PCI_ATR_TRSL_ADDR_MASK),
+	       base + XR3PCI_ATR_TRSL_ADDR_LOW);
+	writel(upper_32_bits(trsl_addr), base + XR3PCI_ATR_TRSL_ADDR_HIGH);
+	writel(trsl_param, base + XR3PCI_ATR_TRSL_PARAM);
+
+	dev_dbg(priv->dev, "ATR entry: 0x%010llx %s 0x%010llx [0x%010llx] (param: 0x%06x)\n",
+		src_addr, (trsl_param & XR3PCI_ATR_TRSL_DIR) ? "<-" : "->",
+		trsl_addr, (u64)window_size, trsl_param);
+	return 0;
+}
+
+static int starfive_pcie_atr_init(struct starfive_pcie *priv)
+{
+	struct udevice *ctlr = pci_get_controller(priv->dev);
+	struct pci_controller *hose = dev_get_uclass_priv(ctlr);
+	int i, ret;
+
+	/*
+	 * As the two host bridges in JH7110 soc have the same default
+	 * address translation table, this cause the second root port can't
+	 * access it's host bridge config space correctly.
+	 * To workaround, config the ATR of host bridge config space by SW.
+	 */
+
+	ret = starfive_pcie_set_atr_entry(priv,
+					  (phys_addr_t)priv->cfg_base,
+					  0,
+					  1 << XR3_PCI_ECAM_SIZE,
+					  XR3PCI_ATR_TRSLID_PCIE_CONFIG);
+	if (ret)
+		return ret;
+
+	for (i = 0; i < hose->region_count; i++) {
+		if (hose->regions[i].flags == PCI_REGION_SYS_MEMORY)
+			continue;
+
+		/* Only support identity mappings. */
+		if (hose->regions[i].bus_start !=
+		    hose->regions[i].phys_start)
+			return -EINVAL;
+
+		ret = starfive_pcie_set_atr_entry(priv,
+						  hose->regions[i].phys_start,
+						  hose->regions[i].bus_start,
+						  hose->regions[i].size,
+						  XR3PCI_ATR_TRSLID_PCIE_MEMORY);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int starfive_pcie_get_syscon(struct udevice *dev)
+{
+	struct starfive_pcie *priv = dev_get_priv(dev);
+	struct udevice *syscon;
+	struct ofnode_phandle_args syscfg_phandle;
+	u32 cells[4];
+	int ret;
+
+	/* get corresponding syscon phandle */
+	ret = dev_read_phandle_with_args(dev, "starfive,stg-syscon", NULL, 0, 0,
+					 &syscfg_phandle);
+
+	if (ret < 0) {
+		dev_err(dev, "Can't get syscfg phandle: %d\n", ret);
+		return ret;
+	}
+
+	ret = uclass_get_device_by_ofnode(UCLASS_SYSCON, syscfg_phandle.node,
+					  &syscon);
+	if (ret) {
+		dev_err(dev, "Unable to find syscon device (%d)\n", ret);
+		return ret;
+	}
+
+	priv->regmap = syscon_get_regmap(syscon);
+	if (!priv->regmap) {
+		dev_err(dev, "Unable to find regmap\n");
+		return -ENODEV;
+	}
+
+	/* get syscon register offset */
+	ret = dev_read_u32_array(dev, "starfive,stg-syscon",
+				 cells, ARRAY_SIZE(cells));
+	if (ret) {
+		dev_err(dev, "Get syscon register err %d\n", ret);
+		return -EINVAL;
+	}
+
+	dev_dbg(dev, "Get syscon values: %x, %x, %x\n",
+		cells[1], cells[2], cells[3]);
+	priv->stg_arfun = cells[1];
+	priv->stg_awfun = cells[2];
+	priv->stg_rp_nep = cells[3];
+
+	return 0;
+}
+
+static int starfive_pcie_parse_dt(struct udevice *dev)
+{
+	struct starfive_pcie *priv = dev_get_priv(dev);
+	int ret;
+
+	priv->reg_base = (void *)dev_read_addr_name(dev, "reg");
+	if (priv->reg_base == (void __iomem *)FDT_ADDR_T_NONE) {
+		dev_err(dev, "Missing required reg address range\n");
+		return -EINVAL;
+	}
+
+	priv->cfg_base = (void *)dev_read_addr_name(dev, "config");
+	if (priv->cfg_base == (void __iomem *)FDT_ADDR_T_NONE) {
+		dev_err(dev, "Missing required config address range");
+		return -EINVAL;
+	}
+
+	ret = starfive_pcie_get_syscon(dev);
+	if (ret) {
+		dev_err(dev, "Can't get syscon: %d\n", ret);
+		return ret;
+	}
+
+	ret = reset_get_bulk(dev, &priv->rsts);
+	if (ret) {
+		dev_err(dev, "Can't get reset: %d\n", ret);
+		return ret;
+	}
+
+	ret = clk_get_bulk(dev, &priv->clks);
+	if (ret) {
+		dev_err(dev, "Can't get clock: %d\n", ret);
+		return ret;
+	}
+
+	ret = gpio_request_by_name(dev, "reset-gpios", 0, &priv->reset_gpio,
+				   GPIOD_IS_OUT);
+	if (ret) {
+		dev_err(dev, "Can't get reset-gpio: %d\n", ret);
+		return ret;
+	}
+
+	if (!dm_gpio_is_valid(&priv->reset_gpio)) {
+		dev_err(dev, "reset-gpio is not valid\n");
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static int starfive_pcie_init_port(struct udevice *dev)
+{
+	int ret, i;
+	unsigned int value;
+	struct starfive_pcie *priv = dev_get_priv(dev);
+
+	ret = clk_enable_bulk(&priv->clks);
+	if (ret) {
+		dev_err(dev, "Failed to enable clks (ret=%d)\n", ret);
+		return ret;
+	}
+
+	ret = reset_deassert_bulk(&priv->rsts);
+	if (ret) {
+		dev_err(dev, "Failed to deassert resets (ret=%d)\n", ret);
+		goto err_deassert_clk;
+	}
+
+	dm_gpio_set_value(&priv->reset_gpio, 1);
+	/* Disable physical functions except #0 */
+	for (i = 1; i < PLDA_FUNC_NUM; i++) {
+		regmap_update_bits(priv->regmap,
+				   priv->stg_arfun,
+				   STG_SYSCON_AXI4_SLVL_ARFUNC_MASK,
+				   (i << PLDA_PHY_FUNC_SHIFT) <<
+				   STG_SYSCON_AXI4_SLVL_ARFUNC_SHIFT);
+		regmap_update_bits(priv->regmap,
+				   priv->stg_awfun,
+				   STG_SYSCON_AXI4_SLVL_AWFUNC_MASK,
+				   i << PLDA_PHY_FUNC_SHIFT);
+
+		value = readl(priv->reg_base + PCI_MISC);
+		value |= PLDA_FUNCTION_DIS;
+		writel(value, priv->reg_base + PCI_MISC);
+	}
+
+	/* Disable physical functions */
+	regmap_update_bits(priv->regmap,
+			   priv->stg_arfun,
+			   STG_SYSCON_AXI4_SLVL_ARFUNC_MASK,
+			   0);
+	regmap_update_bits(priv->regmap,
+			   priv->stg_awfun,
+			   STG_SYSCON_AXI4_SLVL_AWFUNC_MASK,
+			   0);
+
+	/* Enable root port */
+	value = readl(priv->reg_base + GEN_SETTINGS);
+	value |= PLDA_RP_ENABLE;
+	writel(value, priv->reg_base + GEN_SETTINGS);
+
+	/* PCIe PCI Standard Configuration Identification Settings. */
+	value = readl(priv->reg_base + PCIE_PCI_IDS);
+	value &= 0xff;
+	value |= (PCI_CLASS_BRIDGE_PCI_NORMAL << IDS_CLASS_CODE_SHIFT);
+	writel(value, priv->reg_base + PCIE_PCI_IDS);
+
+	/*
+	 * The LTR message forwarding of PCIe Message Reception was set by core
+	 * as default, but the forward id & addr are also need to be reset.
+	 * If we do not disable LTR message forwarding here, or set a legal
+	 * forwarding address, the kernel will get stuck after this driver probe.
+	 * To workaround, disable the LTR message forwarding support on
+	 * PCIe Message Reception.
+	 */
+	value = readl(priv->reg_base + PMSG_SUPPORT_RX);
+	value &= ~PMSG_LTR_SUPPORT;
+	writel(value, priv->reg_base + PMSG_SUPPORT_RX);
+
+	/* Prefetchable memory window 64-bit addressing support */
+	value = readl(priv->reg_base + PCIE_WINROM);
+	value |= PREF_MEM_WIN_64_SUPPORT;
+	writel(value, priv->reg_base + PCIE_WINROM);
+
+	starfive_pcie_atr_init(priv);
+
+	dm_gpio_set_value(&priv->reset_gpio, 0);
+	/* Ensure that PERST in default at least 300 ms */
+	mdelay(300);
+
+	return 0;
+
+err_deassert_clk:
+	clk_disable_bulk(&priv->clks);
+	return ret;
+}
+
+static int starfive_pcie_probe(struct udevice *dev)
+{
+	struct starfive_pcie *priv = dev_get_priv(dev);
+	int ret;
+
+	priv->atr_table_num = 0;
+	priv->dev = dev;
+
+	ret = starfive_pcie_parse_dt(dev);
+	if (ret)
+		return ret;
+
+	regmap_update_bits(priv->regmap,
+			   priv->stg_rp_nep,
+			   STG_SYSCON_K_RP_NEP_MASK,
+			   STG_SYSCON_K_RP_NEP_MASK);
+
+	regmap_update_bits(priv->regmap,
+			   priv->stg_awfun,
+			   STG_SYSCON_CKREF_SRC_MASK,
+			   2 << STG_SYSCON_CKREF_SRC_SHIFT);
+
+	regmap_update_bits(priv->regmap,
+			   priv->stg_awfun,
+			   STG_SYSCON_CLKREQ_MASK,
+			   STG_SYSCON_CLKREQ_MASK);
+
+	ret = starfive_pcie_init_port(dev);
+	if (ret)
+		return ret;
+
+	dev_err(dev, "Starfive PCIe bus probed.\n");
+
+	return 0;
+}
+
+static const struct dm_pci_ops starfive_pcie_ops = {
+	.read_config	= starfive_pcie_config_read,
+	.write_config	= starfive_pcie_config_write,
+};
+
+static const struct udevice_id starfive_pcie_ids[] = {
+	{ .compatible = "starfive,jh7110-pcie" },
+	{ }
+};
+
+U_BOOT_DRIVER(starfive_pcie_drv) = {
+	.name			= "starfive_7110_pcie",
+	.id			= UCLASS_PCI,
+	.of_match		= starfive_pcie_ids,
+	.ops			= &starfive_pcie_ops,
+	.probe			= starfive_pcie_probe,
+	.priv_auto	= sizeof(struct starfive_pcie),
+};
-- 
2.17.1