[PATCH 2/2] PCI: mediatek: add support for PCIE found on MT7623/MT2701

[John Crispin <blogic@openwrt.org>]

Add PCIE controller support on MediaTek MT2701/MT7623. The driver supports
a single Root complex (RC) with 3 Root Ports. The SoCs supports a Gen2
1-lan Link on each port.

Signed-off-by: John Crispin <blogic@openwrt.org>
---
 arch/arm/mach-mediatek/Kconfig   |    1 +
 drivers/pci/host/Kconfig         |   11 +
 drivers/pci/host/Makefile        |    1 +
 drivers/pci/host/pcie-mediatek.c |  604 ++++++++++++++++++++++++++++++++++++++
 4 files changed, 617 insertions(+)
 create mode 100644 drivers/pci/host/pcie-mediatek.c

diff --git a/arch/arm/mach-mediatek/Kconfig b/arch/arm/mach-mediatek/Kconfig
index 7fb605e..a7fef77 100644
--- a/arch/arm/mach-mediatek/Kconfig
+++ b/arch/arm/mach-mediatek/Kconfig
@@ -24,6 +24,7 @@ config MACH_MT6592
 config MACH_MT7623
 	bool "MediaTek MT7623 SoCs support"
 	default ARCH_MEDIATEK
+	select MIGHT_HAVE_PCI
 
 config MACH_MT8127
 	bool "MediaTek MT8127 SoCs support"
diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig
index f131ba9..912f0e1 100644
--- a/drivers/pci/host/Kconfig
+++ b/drivers/pci/host/Kconfig
@@ -172,4 +172,15 @@ config PCI_HISI
 	help
 	  Say Y here if you want PCIe controller support on HiSilicon HIP05 SoC
 
+config PCIE_MTK
+	bool "Mediatek PCIe Controller"
+	depends on MACH_MT2701 || MACH_MT7623
+	depends on OF
+	depends on PCI
+	help
+	  Say Y here if you want to enable PCI controller support on Mediatek MT7623.
+	  MT7623 PCIe supports single Root complex (RC) with 3 Root Ports.
+	  Each port supports a Gen2 1-lan Link.
+	  PCIe include one Host/PCI bridge and 3 PCIe MAC.
+
 endmenu
diff --git a/drivers/pci/host/Makefile b/drivers/pci/host/Makefile
index 9d4d3c6..3b53374 100644
--- a/drivers/pci/host/Makefile
+++ b/drivers/pci/host/Makefile
@@ -20,3 +20,4 @@ obj-$(CONFIG_PCIE_IPROC_BCMA) += pcie-iproc-bcma.o
 obj-$(CONFIG_PCIE_ALTERA) += pcie-altera.o
 obj-$(CONFIG_PCIE_ALTERA_MSI) += pcie-altera-msi.o
 obj-$(CONFIG_PCI_HISI) += pcie-hisi.o
+obj-$(CONFIG_PCIE_MTK) += pcie-mediatek.o
diff --git a/drivers/pci/host/pcie-mediatek.c b/drivers/pci/host/pcie-mediatek.c
new file mode 100644
index 0000000..6bd283a
--- /dev/null
+++ b/drivers/pci/host/pcie-mediatek.c
@@ -0,0 +1,604 @@
+/*
+ *  Mediatek MT2701/MT7623 SoC PCIE support
+ *
+ *  Copyright (C) 2015 Mediatek
+ *  Copyright (C) 2015 Ziv Huang <ziv.huang@mediatek.com>
+ *  Copyright (C) 2015 John Crispin <blogic@openwrt.org>
+ *
+ *  This program is free software; you can redistribute it and/or modify it
+ *  under the terms of the GNU General Public License version 2 as published
+ *  by the Free Software Foundation.
+ */
+
+#include <linux/kernel.h>
+#include <linux/pci.h>
+#include <linux/ioport.h>
+#include <linux/interrupt.h>
+#include <linux/spinlock.h>
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/delay.h>
+#include <asm/irq.h>
+#include <asm/mach/pci.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_pci.h>
+#include <linux/of_platform.h>
+#include <linux/of_irq.h>
+#include <linux/reset.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+#include <linux/pm_runtime.h>
+#include <linux/clk.h>
+#include <linux/regmap.h>
+#include <linux/mfd/syscon.h>
+
+#define MEMORY_BASE			0x80000000
+
+/* PCIE Registers */
+#define PCICFG				0x00
+#define PCIINT				0x08
+#define PCIENA				0x0c
+#define CFGADDR				0x20
+#define CFGDATA				0x24
+#define MEMBASE				0x28
+#define IOBASE				0x2c
+
+/* per Port Registers */
+#define BAR0SETUP			0x10
+#define IMBASEBAR0			0x18
+#define PCIE_CLASS			0x34
+#define PCIE_SISTAT			0x50
+
+#define MTK_PCIE_HIGH_PERF		BIT(14)
+#define PCIEP0_BASE			0x2000
+#define PCIEP1_BASE			0x3000
+#define PCIEP2_BASE			0x4000
+
+#define PHY_P0_CTL			0x9000
+#define PHY_P1_CTL			0xa000
+#define PHY_P2_CTL			0x4000
+
+#define RSTCTL_PCIE0_RST		BIT(24)
+#define RSTCTL_PCIE1_RST		BIT(25)
+#define RSTCTL_PCIE2_RST		BIT(26)
+
+#define HIFSYS_SYSCFG1			0x14
+#define HIFSYS_SYSCFG1_PHY2_MASK	(0x3 << 20)
+
+static struct mtk_pcie_port {
+	int id;
+	int enable;
+	u32 base;
+	u32 perst_n;
+	u32 interrupt_en;
+	int irq;
+	u32 link;
+	void __iomem *phy_base;
+	struct reset_control *rstc;
+} mtk_pcie_port[] = {
+	{ 0, 0, PCIEP0_BASE, BIT(1), BIT(20) },
+	{ 1, 0, PCIEP1_BASE, BIT(2), BIT(21) },
+	{ 2, 0, PCIEP2_BASE, BIT(3), BIT(22) },
+};
+#define MAX_PORT_NUM		ARRAY_SIZE(mtk_pcie_port)
+#define mtk_foreach_port(p)			\
+		for ((p) = mtk_pcie_port;	\
+		     (p) != &mtk_pcie_port[MAX_PORT_NUM]; (p)++)
+
+struct mtk_pcie {
+	struct device *dev;
+	void __iomem *pcie_base;
+	struct regmap *hifsys;
+
+	struct resource io;
+	struct resource pio;
+	struct resource mem;
+	struct resource prefetch;
+	struct resource busn;
+
+	u32 io_bus_addr;
+	u32 mem_bus_addr;
+
+	struct clk *clk;
+	int pcie_card_link;
+};
+
+static const struct mtk_phy_init {
+	uint32_t reg;
+	uint32_t mask;
+	uint32_t val;
+} mtk_phy_init[] = {
+	{ 0xc00, 0x33000, 0x22000 },
+	{ 0xb04, 0xe0000000, 0x40000000 },
+	{ 0xb00, 0xe, 0x4 },
+	{ 0xc3C, 0xffff0000, 0x3c0000 },
+	{ 0xc48, 0xffff, 0x36 },
+	{ 0xc0c, 0x30000000, 0x10000000 },
+	{ 0xc08, 0x3800c0, 0xc0 },
+	{ 0xc10, 0xf0000, 0x20000 },
+	{ 0xc0c, 0xf000, 0x1000 },
+	{ 0xc14, 0xf0000, 0xa0000 },
+};
+
+static struct mtk_pcie *sys_to_pcie(struct pci_sys_data *sys)
+{
+	return sys->private_data;
+}
+
+static void pcie_w32(struct mtk_pcie *pcie, u32 val, unsigned reg)
+{
+	iowrite32(val, pcie->pcie_base + reg);
+}
+
+static u32 pcie_r32(struct mtk_pcie *pcie, unsigned reg)
+{
+	return ioread32(pcie->pcie_base + reg);
+}
+
+static void pcie_m32(struct mtk_pcie *pcie, u32 mask, u32 val, unsigned reg)
+{
+	u32 v = pcie_r32(pcie, reg);
+
+	v &= mask;
+	v |= val;
+	pcie_w32(pcie, v, reg);
+}
+
+static int pcie_config_read(struct pci_bus *bus, unsigned int devfn, int where,
+			    int size, u32 *val)
+{
+	struct mtk_pcie *pcie = sys_to_pcie(bus->sysdata);
+	unsigned int slot = PCI_SLOT(devfn);
+	u8 func = PCI_FUNC(devfn);
+	u32 address;
+	u32 data;
+	u32 num = 0;
+
+	if (bus)
+		num = bus->number;
+
+	address = (((where & 0xf00) >> 8) << 24) |
+		  (num << 16) |
+		  (slot << 11) |
+		  (func << 8) |
+		  (where & 0xfc);
+
+	pcie_m32(pcie, 0xf0000000, address, CFGADDR);
+	data = pcie_r32(pcie, CFGDATA);
+
+	switch (size) {
+	case 1:
+		*val = (data >> ((where & 3) << 3)) & 0xff;
+		break;
+	case 2:
+		*val = (data >> ((where & 3) << 3)) & 0xffff;
+		break;
+	case 4:
+		*val = data;
+		break;
+	}
+
+	return PCIBIOS_SUCCESSFUL;
+}
+
+static int pcie_config_write(struct pci_bus *bus, unsigned int devfn, int where,
+			     int size, u32 val)
+{
+	struct mtk_pcie *pcie = sys_to_pcie(bus->sysdata);
+	unsigned int slot = PCI_SLOT(devfn);
+	u8 func = PCI_FUNC(devfn);
+	u32 address;
+	u32 data;
+	u32 num = 0;
+
+	if (bus)
+		num = bus->number;
+
+	address = (((where & 0xf00) >> 8) << 24) |
+		  (num << 16) | (slot << 11) | (func << 8) | (where & 0xfc);
+	pcie_m32(pcie, 0xf0000000, address, CFGADDR);
+	data = pcie_r32(pcie, CFGDATA);
+
+	switch (size) {
+	case 1:
+		data = (data & ~(0xff << ((where & 3) << 3))) |
+		       (val << ((where & 3) << 3));
+		break;
+	case 2:
+		data = (data & ~(0xffff << ((where & 3) << 3))) |
+		       (val << ((where & 3) << 3));
+		break;
+	case 4:
+		data = val;
+		break;
+	}
+	pcie_w32(pcie, data, CFGDATA);
+
+	return PCIBIOS_SUCCESSFUL;
+}
+
+static struct pci_ops mtk_pcie_ops = {
+	.read   = pcie_config_read,
+	.write  = pcie_config_write,
+};
+
+static int __init mtk_pcie_setup(int nr, struct pci_sys_data *sys)
+{
+	struct mtk_pcie *pcie = sys_to_pcie(sys);
+
+	if (!pcie->pcie_card_link)
+		return -1;
+
+	request_resource(&ioport_resource, &pcie->pio);
+	request_resource(&iomem_resource, &pcie->mem);
+
+	pci_add_resource_offset(&sys->resources, &pcie->mem, sys->mem_offset);
+	pci_add_resource_offset(&sys->resources, &pcie->pio, sys->io_offset);
+	pci_add_resource(&sys->resources, &pcie->busn);
+
+	return 1;
+}
+
+static struct pci_bus * __init mtk_pcie_scan_bus(int nr,
+						struct pci_sys_data *sys)
+{
+	struct mtk_pcie *pcie = sys_to_pcie(sys);
+	struct pci_bus *bus;
+
+	if (!pcie->pcie_card_link)
+		return NULL;
+
+	bus = pci_create_root_bus(pcie->dev, sys->busnr, &mtk_pcie_ops, sys,
+				  &sys->resources);
+	if (!bus)
+		return NULL;
+
+	pci_scan_child_bus(bus);
+
+	return bus;
+}
+
+static int __init mtk_pcie_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
+{
+	struct mtk_pcie *pcie = sys_to_pcie(dev->bus->sysdata);
+	struct mtk_pcie_port *port;
+	int irq = -1;
+
+	if (!pcie->pcie_card_link)
+		return irq;
+
+	mtk_foreach_port(port)
+		if (port->id == slot)
+			irq = port->irq;
+
+	return irq;
+}
+
+static void mtk_pcie_configure_phy(struct mtk_pcie *pcie,
+				   struct mtk_pcie_port *port)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(mtk_phy_init); i++) {
+		void __iomem *phy_addr = port->phy_base + mtk_phy_init[i].reg;
+		u32 val = ioread32(phy_addr);
+
+		val &= ~mtk_phy_init[i].mask;
+		val |= mtk_phy_init[i].val;
+		iowrite32(val, phy_addr);
+	}
+	usleep_range(5000, 6000);
+}
+
+static void mtk_pcie_configure_rc(struct mtk_pcie *pcie,
+				  struct mtk_pcie_port *port,
+				  struct pci_bus *bus)
+{
+	u32 val = 0;
+
+	pcie_config_write(bus,
+			  port->id << 3,
+			  PCI_BASE_ADDRESS_0, 4, MEMORY_BASE);
+
+	pcie_config_read(bus,
+			 port->id << 3, PCI_BASE_ADDRESS_0, 4, &val);
+
+	/* Configure RC Credit */
+	pcie_config_read(bus, port->id << 3, 0x73c, 4, &val);
+	val &= ~(0x9fff) << 16;
+	val |= 0x806c << 16;
+	pcie_config_write(bus, port->id << 3, 0x73c, 4, val);
+
+	/* Configure RC FTS number */
+	pcie_config_read(bus, port->id << 3, 0x70c, 4, &val);
+	val &= ~(0xff3) << 8;
+	val |= 0x50 << 8;
+	pcie_config_write(bus, port->id << 3, 0x70c, 4, val);
+}
+
+static void mtk_pcie_preinit(struct mtk_pcie *pcie)
+{
+	struct mtk_pcie_port *port;
+	u32 val = 0;
+	struct pci_bus bus;
+	struct pci_sys_data sys;
+
+	memset(&bus, 0, sizeof(bus));
+	memset(&sys, 0, sizeof(sys));
+	bus.sysdata = (void *)&sys;
+	sys.private_data = (void *)pcie;
+
+	pcibios_min_io = 0;
+	pcibios_min_mem = 0;
+
+	/* The PHY on Port 2 is shared with USB */
+	if (mtk_pcie_port[2].enable)
+		regmap_update_bits(pcie->hifsys, HIFSYS_SYSCFG1,
+				   HIFSYS_SYSCFG1_PHY2_MASK, 0x0);
+
+	/* PCIe RC Reset */
+	mtk_foreach_port(port)
+		if (port->enable)
+			reset_control_assert(port->rstc);
+	usleep_range(1000, 2000);
+	mtk_foreach_port(port)
+		if (port->enable)
+			reset_control_deassert(port->rstc);
+	usleep_range(1000, 2000);
+
+	/* Configure PCIe PHY */
+	mtk_foreach_port(port)
+		if (port->enable)
+			mtk_pcie_configure_phy(pcie, port);
+
+	/* PCIe EP reset */
+	val = 0;
+	mtk_foreach_port(port)
+		if (port->enable)
+			val |= port->perst_n;
+	pcie_w32(pcie, pcie_r32(pcie, PCICFG) | val, PCICFG);
+	usleep_range(1000, 2000);
+	pcie_w32(pcie, pcie_r32(pcie, PCICFG) & ~val, PCICFG);
+	usleep_range(1000, 2000);
+	msleep(100);
+
+	/* check the link status */
+	val = 0;
+	mtk_foreach_port(port) {
+		if (port->enable) {
+			if ((pcie_r32(pcie, port->base + PCIE_SISTAT) & 0x1))
+				port->link = 1;
+			else
+				reset_control_assert(port->rstc);
+		}
+	}
+
+	mtk_foreach_port(port)
+		if (port->link)
+			pcie->pcie_card_link++;
+
+	if (!pcie->pcie_card_link)
+		return;
+
+	pcie_w32(pcie, pcie->mem_bus_addr, MEMBASE);
+	pcie_w32(pcie, pcie->io_bus_addr, IOBASE);
+
+	mtk_foreach_port(port) {
+		if (port->link) {
+			pcie_m32(pcie, 0, port->interrupt_en, PCIENA);
+			pcie_w32(pcie, 0x7fff0001, port->base + BAR0SETUP);
+			pcie_w32(pcie, MEMORY_BASE, port->base + IMBASEBAR0);
+			pcie_w32(pcie, 0x06040001, port->base + PCIE_CLASS);
+		}
+	}
+
+	mtk_foreach_port(port)
+		if (port->link)
+			mtk_pcie_configure_rc(pcie, port, &bus);
+}
+
+static int mtk_pcie_parse_dt(struct mtk_pcie *pcie)
+{
+	struct device_node *np = pcie->dev->of_node, *port;
+	struct of_pci_range_parser parser;
+	struct of_pci_range range;
+	struct resource res;
+	int err;
+
+	pcie->hifsys = syscon_regmap_lookup_by_phandle(np, "mediatek,hifsys");
+	if (IS_ERR(pcie->hifsys)) {
+		dev_err(pcie->dev, "missing \"mediatek,hifsys\" phandle\n");
+		return PTR_ERR(pcie->hifsys);
+	}
+
+	if (of_pci_range_parser_init(&parser, np)) {
+		dev_err(pcie->dev, "missing \"ranges\" property\n");
+		return -EINVAL;
+	}
+
+	for_each_of_pci_range(&parser, &range) {
+		err = of_pci_range_to_resource(&range, np, &res);
+		if (err < 0) {
+			dev_err(pcie->dev, "failed to read resource range\n");
+			return err;
+		}
+
+		switch (res.flags & IORESOURCE_TYPE_BITS) {
+		case IORESOURCE_IO:
+			memcpy(&pcie->pio, &res, sizeof(res));
+			pcie->pio.start = (resource_size_t)range.pci_addr;
+			pcie->pio.end = (resource_size_t)
+					(range.pci_addr + range.size - 1);
+			pcie->io_bus_addr = (resource_size_t)range.cpu_addr;
+			break;
+
+		case IORESOURCE_MEM:
+			if (res.flags & IORESOURCE_PREFETCH) {
+				memcpy(&pcie->prefetch, &res, sizeof(res));
+				pcie->prefetch.name = "prefetchable";
+				pcie->prefetch.start =
+					(resource_size_t)range.pci_addr;
+				pcie->prefetch.end = (resource_size_t)
+					(range.pci_addr + range.size - 1);
+			} else {
+				memcpy(&pcie->mem, &res, sizeof(res));
+				pcie->mem.name = "non-prefetchable";
+				pcie->mem.start = (resource_size_t)
+					range.pci_addr;
+				pcie->prefetch.end = (resource_size_t)
+					(range.pci_addr + range.size - 1);
+				pcie->mem_bus_addr = (resource_size_t)
+					range.cpu_addr;
+			}
+			break;
+		}
+	}
+
+	err = of_pci_parse_bus_range(np, &pcie->busn);
+	if (err < 0) {
+		dev_err(pcie->dev, "failed to parse ranges property: %d\n",
+			err);
+		pcie->busn.name = np->name;
+		pcie->busn.start = 0;
+		pcie->busn.end = 0xff;
+		pcie->busn.flags = IORESOURCE_BUS;
+	}
+
+	/* parse root ports */
+	for_each_child_of_node(np, port) {
+		unsigned int index;
+		char rst[] = "pcie0";
+
+		err = of_pci_get_devfn(port);
+		if (err < 0) {
+			dev_err(pcie->dev, "failed to parse address: %d\n",
+				err);
+			return err;
+		}
+
+		index = PCI_SLOT(err);
+
+		if (index > MAX_PORT_NUM) {
+			dev_err(pcie->dev, "invalid port number: %d\n", index);
+			continue;
+		}
+		index--;
+
+		if (!of_device_is_available(port))
+			continue;
+
+		rst[4] += index;
+		mtk_pcie_port[index].rstc = devm_reset_control_get(pcie->dev,
+								   rst);
+		if (!IS_ERR(mtk_pcie_port[index].rstc))
+			mtk_pcie_port[index].enable = 1;
+	}
+	return 0;
+}
+
+static int mtk_pcie_get_resources(struct mtk_pcie *pcie)
+{
+	struct platform_device *pdev = to_platform_device(pcie->dev);
+	struct mtk_pcie_port *port;
+	struct resource *res;
+
+	pcie->clk = devm_clk_get(&pdev->dev, "pcie");
+	if (IS_ERR(pcie->clk)) {
+		dev_err(&pdev->dev, "Failed to get pcie clk\n");
+		return PTR_ERR(pcie->clk);
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	pcie->pcie_base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(pcie->pcie_base)) {
+		dev_err(&pdev->dev, "Failed to get pcie range\n");
+		return PTR_ERR(pcie->pcie_base);
+	}
+
+	mtk_foreach_port(port) {
+		if (!port->enable)
+			continue;
+		res = platform_get_resource(pdev, IORESOURCE_MEM, port->id + 1);
+		port->phy_base = devm_ioremap_resource(&pdev->dev, res);
+		if (IS_ERR(port->phy_base)) {
+			dev_err(&pdev->dev, "Failed to get pcie phy%d range\n",
+				port->id);
+			return PTR_ERR(port->phy_base);
+		}
+		port->irq = platform_get_irq(pdev, port->id);
+	}
+
+	return clk_prepare_enable(pcie->clk);
+}
+
+static int mtk_pcie_probe(struct platform_device *pdev)
+{
+	struct mtk_pcie *pcie;
+	struct hw_pci hw;
+	int ret;
+
+	pcie = devm_kzalloc(&pdev->dev, sizeof(*pcie), GFP_KERNEL);
+	if (!pcie)
+		return -ENOMEM;
+
+	pcie->dev = &pdev->dev;
+	ret = mtk_pcie_parse_dt(pcie);
+	if (ret < 0)
+		return ret;
+
+	pm_runtime_enable(&pdev->dev);
+	pm_runtime_get_sync(&pdev->dev);
+
+	ret = mtk_pcie_get_resources(pcie);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "failed to request resources: %d\n", ret);
+		goto err_out;
+	}
+
+	mtk_pcie_preinit(pcie);
+
+	memset(&hw, 0, sizeof(hw));
+	hw.nr_controllers = 1;
+	hw.private_data = (void **)&pcie;
+	hw.setup = mtk_pcie_setup;
+	hw.map_irq = mtk_pcie_map_irq;
+	hw.scan = mtk_pcie_scan_bus;
+
+	pci_common_init_dev(pcie->dev, &hw);
+	platform_set_drvdata(pdev, pcie);
+
+	return 0;
+
+err_out:
+	clk_disable_unprepare(pcie->clk);
+	pm_runtime_put_sync(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
+
+	return ret;
+}
+
+static const struct of_device_id mtk_pcie_ids[] = {
+	{ .compatible = "mediatek,mt2701-pcie" },
+	{ .compatible = "mediatek,mt7623-pcie" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, mtk_pcie_ids);
+
+static struct platform_driver mtk_pcie_driver = {
+	.probe = mtk_pcie_probe,
+	.driver = {
+		.name = "mediatek-pcie",
+		.owner = THIS_MODULE,
+		.of_match_table = of_match_ptr(mtk_pcie_ids),
+	},
+};
+
+static int __init mtk_pcie_init(void)
+{
+	return platform_driver_register(&mtk_pcie_driver);
+}
+
+module_init(mtk_pcie_init);
-- 
1.7.10.4