The "a" version of the MT7620 has single port PCIE bus. The driver is
straightforward without any special magic required. The driver works on
MT7620 and MT7628. There are a few magic values that get written to the
pcie phy and a register of which we only know the name. I marked these
places as vodoo in the comments above the code.
Signed-off-by: John Crispin <blogic@xxxxxxxxxxx>
---
arch/mips/pci/Makefile | 1 +
arch/mips/pci/pci-mt7620.c | 426 ++++++++++++++++++++++++++++++++++++++++++++
arch/mips/ralink/Kconfig | 1 +
3 files changed, 428 insertions(+)
create mode 100644 arch/mips/pci/pci-mt7620.c
diff --git a/arch/mips/pci/Makefile b/arch/mips/pci/Makefile
index 2eda01e..139ad1d 100644
--- a/arch/mips/pci/Makefile
+++ b/arch/mips/pci/Makefile
@@ -43,6 +43,7 @@ obj-$(CONFIG_SIBYTE_BCM1x80) += pci-bcm1480.o pci-bcm1480ht.o
obj-$(CONFIG_SNI_RM) += fixup-sni.o ops-sni.o
obj-$(CONFIG_LANTIQ) += fixup-lantiq.o
obj-$(CONFIG_PCI_LANTIQ) += pci-lantiq.o ops-lantiq.o
+obj-$(CONFIG_SOC_MT7620) += pci-mt7620.o
obj-$(CONFIG_SOC_RT288X) += pci-rt2880.o
obj-$(CONFIG_SOC_RT3883) += pci-rt3883.o
obj-$(CONFIG_TANBAC_TB0219) += fixup-tb0219.o
diff --git a/arch/mips/pci/pci-mt7620.c b/arch/mips/pci/pci-mt7620.c
new file mode 100644
index 0000000..a009ee4
--- /dev/null
+++ b/arch/mips/pci/pci-mt7620.c
@@ -0,0 +1,426 @@
+/*
+ * Ralink MT7620A SoC PCI support
+ *
+ * Copyright (C) 2007-2013 Bruce Chang (Mediatek)
+ * Copyright (C) 2013-2016 John Crispin <blogic@xxxxxxxxxxx>
+ *
+ * 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/types.h>
+#include <linux/pci.h>
+#include <linux/io.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/of_pci.h>
+#include <linux/reset.h>
+#include <linux/platform_device.h>
+
+#include <asm/mach-ralink/ralink_regs.h>
+#include <asm/mach-ralink/mt7620.h>
+
+#define RALINK_PCI_IO_MAP_BASE 0x10160000
+#define RALINK_PCI_MEMORY_BASE 0x0
+
+#define RALINK_INT_PCIE0 4
+
+#define RALINK_CLKCFG1 0x30
+#define RALINK_GPIOMODE 0x60
+
+#define PPLL_CFG1 0x9c
+#define PDRV_SW_SET BIT(23)
+
+#define PPLL_DRV 0xa0
+#define PDRV_SW_SET (1<<31)
+#define LC_CKDRVPD (1<<19)
+#define LC_CKDRVOHZ (1<<18)
+#define LC_CKDRVHZ (1<<17)
+#define LC_CKTEST (1<<16)
+
+/* PCI Bridge registers */
+#define RALINK_PCI_PCICFG_ADDR 0x00
+#define PCIRST BIT(1)
+
+#define RALINK_PCI_PCIENA 0x0C
+#define PCIINT2 BIT(20)
+
+#define RALINK_PCI_CONFIG_ADDR 0x20
+#define RALINK_PCI_CONFIG_DATA_VIRT_REG 0x24
+#define RALINK_PCI_MEMBASE 0x28
+#define RALINK_PCI_IOBASE 0x2C
+
+/* PCI RC registers */
+#define RALINK_PCI0_BAR0SETUP_ADDR 0x10
+#define RALINK_PCI0_IMBASEBAR0_ADDR 0x18
+#define RALINK_PCI0_ID 0x30
+#define RALINK_PCI0_CLASS 0x34
+#define RALINK_PCI0_SUBID 0x38
+#define RALINK_PCI0_STATUS 0x50
+#define PCIE_LINK_UP_ST BIT(0)
+
+#define PCIEPHY0_CFG 0x90
+
+#define RALINK_PCIEPHY_P0_CTL_OFFSET 0x7498
+#define RALINK_PCIE0_CLK_EN (1 << 26)
+
+#define BUSY 0x80000000
+#define WAITRETRY_MAX 10
+#define WRITE_MODE (1UL << 23)
+#define DATA_SHIFT 0
+#define ADDR_SHIFT 8
+
+
+static void __iomem *bridge_base;
+static void __iomem *pcie_base;
+
+static struct reset_control *rstpcie0;
+
+static inline void bridge_w32(u32 val, unsigned reg)
+{
+ iowrite32(val, bridge_base + reg);
+}
+
+static inline u32 bridge_r32(unsigned reg)
+{
+ return ioread32(bridge_base + reg);
+}
+
+static inline void pcie_w32(u32 val, unsigned reg)
+{
+ iowrite32(val, pcie_base + reg);
+}
+
+static inline u32 pcie_r32(unsigned reg)
+{
+ return ioread32(pcie_base + reg);
+}
+
+static inline void pcie_m32(u32 clr, u32 set, unsigned reg)
+{
+ u32 val = pcie_r32(reg);
+
+ val &= ~clr;
+ val |= set;
+ pcie_w32(val, reg);
+}
+
+static int wait_pciephy_busy(void)
+{
+ unsigned long reg_value = 0x0, retry = 0;
+
+ while (1) {
+ reg_value = pcie_r32(PCIEPHY0_CFG);
+
+ if (reg_value & BUSY)
+ mdelay(100);
+ else
+ break;
+ if (retry++ > WAITRETRY_MAX) {
+ printk(KERN_WARN "PCIE-PHY retry failed.\n");
+ return -1;
+ }
+ }
+ return 0;
+}
+
+static void pcie_phy(unsigned long addr, unsigned long val)
+{
+ wait_pciephy_busy();
+ pcie_w32(WRITE_MODE | (val << DATA_SHIFT) | (addr << ADDR_SHIFT),
+ PCIEPHY0_CFG);
+ mdelay(1);
+ wait_pciephy_busy();
+}
+
+static int pci_config_read(struct pci_bus *bus, unsigned int devfn, int where,
+ int size, u32 *val)
+{
+ 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) | 0x80000000;
+ bridge_w32(address, RALINK_PCI_CONFIG_ADDR);
+ data = bridge_r32(RALINK_PCI_CONFIG_DATA_VIRT_REG);
+
+ 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 pci_config_write(struct pci_bus *bus, unsigned int devfn, int where,
+ int size, u32 val)
+{
+ 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) | 0x80000000;
+ bridge_w32(address, RALINK_PCI_CONFIG_ADDR);
+ data = bridge_r32(RALINK_PCI_CONFIG_DATA_VIRT_REG);
+
+ 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;
+ }
+
+ bridge_w32(data, RALINK_PCI_CONFIG_DATA_VIRT_REG);
+
+ return PCIBIOS_SUCCESSFUL;
+}
+
+struct pci_ops mt7620_pci_ops = {
+ .read = pci_config_read,
+ .write = pci_config_write,
+};
+
+static struct resource mt7620_res_pci_mem1;
+static struct resource mt7620_res_pci_io1;
+struct pci_controller mt7620_controller = {
+ .pci_ops = &mt7620_pci_ops,
+ .mem_resource = &mt7620_res_pci_mem1,
+ .mem_offset = 0x00000000UL,
+ .io_resource = &mt7620_res_pci_io1,
+ .io_offset = 0x00000000UL,
+ .io_map_base = 0xa0000000,
+};
+
+static int mt7620_pci_hw_init(struct platform_device *pdev)
+{
+ /* bypass PCIe DLL */
+ pcie_phy(0x0, 0x80);
+ pcie_phy(0x1, 0x04);
+
+ /* Elastic buffer control */
+ pcie_phy(0x68, 0xB4);
+
+ /* put core into reset */
+ pcie_m32(0, PCIRST, RALINK_PCI_PCICFG_ADDR);
+ reset_control_assert(rstpcie0);
+
+ /* disable power and all clocks */
+ rt_sysc_m32(RALINK_PCIE0_CLK_EN, 0, RALINK_CLKCFG1);
+ rt_sysc_m32(LC_CKDRVPD, PDRV_SW_SET, PPLL_DRV);
+
+ /* bring core out of reset */
+ reset_control_deassert(rstpcie0);
+ rt_sysc_m32(0, RALINK_PCIE0_CLK_EN, RALINK_CLKCFG1);
+ mdelay(100);
+
+ if (!(rt_sysc_r32(PPLL_CFG1) & PDRV_SW_SET)) {
+ dev_err(&pdev->dev, "MT7620 PPLL unlock\n");
+ reset_control_assert(rstpcie0);
+ rt_sysc_m32(RALINK_PCIE0_CLK_EN, 0, RALINK_CLKCFG1);
+ return -1;
+ }
+
+ /* power up the bus */
+ rt_sysc_m32(LC_CKDRVHZ | LC_CKDRVOHZ, LC_CKDRVPD | PDRV_SW_SET,
+ PPLL_DRV);
+
+ return 0;
+}
+
+static int mt7628_pci_hw_init(struct platform_device *pdev)
+{
+ u32 val = 0;
+
+ /* bring the core out of reset */
+ rt_sysc_m32(BIT(16), 0, RALINK_GPIOMODE);
+ reset_control_deassert(rstpcie0);
+
+ /* enable the pci clk */
+ rt_sysc_m32(0, RALINK_PCIE0_CLK_EN, RALINK_CLKCFG1);
+ mdelay(100);
+
+ /* voodoo from the SDK driver */
+ pcie_m32(~0xff, 0x5, RALINK_PCIEPHY_P0_CTL_OFFSET);
+
+ pci_config_read(NULL, 0, 0x70c, 4, &val);
+ val &= ~(0xff) << 8;
+ val |= 0x50 << 8;
+ pci_config_write(NULL, 0, 0x70c, 4, val);
+
+ pci_config_read(NULL, 0, 0x70c, 4, &val);
+ dev_err(&pdev->dev, "Port 0 N_FTS = %x\n", (unsigned int) val);
+
+ return 0;
+}
+
+static int mt7620_pci_probe(struct platform_device *pdev)
+{
+ struct resource *bridge_res = platform_get_resource(pdev,
+ IORESOURCE_MEM, 0);
+ struct resource *pcie_res = platform_get_resource(pdev,
+ IORESOURCE_MEM, 1);
+ u32 val = 0;
+
+ rstpcie0 = devm_reset_control_get(&pdev->dev, "pcie0");
+ if (IS_ERR(rstpcie0))
+ return PTR_ERR(rstpcie0);
+
+ bridge_base = devm_ioremap_resource(&pdev->dev, bridge_res);
+ if (!bridge_base)
+ return -ENOMEM;
+
+ pcie_base = devm_ioremap_resource(&pdev->dev, pcie_res);
+ if (!pcie_base)
+ return -ENOMEM;
+
+ iomem_resource.start = 0;
+ iomem_resource.end = ~0;
+ ioport_resource.start = 0;
+ ioport_resource.end = ~0;
+
+ /* bring up the pci core */
+ switch (ralink_soc) {
+ case MT762X_SOC_MT7620A:
+ if (mt7620_pci_hw_init(pdev))
+ return -1;
+ break;
+
+ case MT762X_SOC_MT7628AN:
+ if (mt7628_pci_hw_init(pdev))
+ return -1;
+ break;
+
+ default:
+ dev_err(&pdev->dev, "pcie is not supported on this hardware\n");
+ return -1;
+ }
+ mdelay(50);
+
+ /* enable write access */
+ pcie_m32(PCIRST, 0, RALINK_PCI_PCICFG_ADDR);
+ mdelay(100);
+
+ /* check if there is a card present */
+ if ((pcie_r32(RALINK_PCI0_STATUS) & PCIE_LINK_UP_ST) == 0) {
+ reset_control_assert(rstpcie0);
+ rt_sysc_m32(RALINK_PCIE0_CLK_EN, 0, RALINK_CLKCFG1);
+ if (ralink_soc == MT762X_SOC_MT7620A)
+ rt_sysc_m32(LC_CKDRVPD, PDRV_SW_SET, PPLL_DRV);
+ dev_err(&pdev->dev, "PCIE0 no card, disable it(RST&CLK)\n");
+ return -1;
+ }
+
+ /* setup ranges */
+ bridge_w32(0xffffffff, RALINK_PCI_MEMBASE);
+ bridge_w32(RALINK_PCI_IO_MAP_BASE, RALINK_PCI_IOBASE);
+
+ pcie_w32(0x7FFF0001, RALINK_PCI0_BAR0SETUP_ADDR);
+ pcie_w32(RALINK_PCI_MEMORY_BASE, RALINK_PCI0_IMBASEBAR0_ADDR);
+ pcie_w32(0x06040001, RALINK_PCI0_CLASS);
+
+ /* enable interrupts */
+ pcie_m32(0, PCIINT2, RALINK_PCI_PCIENA);
+
+ /* voodoo from the SDK driver */
+ pci_config_read(NULL, 0, 4, 4, &val);
+ pci_config_write(NULL, 0, 4, 4, val | 0x7);
+
+ pci_load_of_ranges(&mt7620_controller, pdev->dev.of_node);
+ register_pci_controller(&mt7620_controller);
+
+ return 0;
+}
+
+int __init pcibios_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
+{
+ u16 cmd;
+ u32 val;
+ int irq = 0;
+
+ if ((dev->bus->number == 0) && (slot == 0)) {
+ pcie_w32(0x7FFF0001, RALINK_PCI0_BAR0SETUP_ADDR);
+ pci_config_write(dev->bus, 0, PCI_BASE_ADDRESS_0, 4,
+ RALINK_PCI_MEMORY_BASE);
+ pci_config_read(dev->bus, 0, PCI_BASE_ADDRESS_0, 4, &val);
+ } else if ((dev->bus->number == 1) && (slot == 0x0)) {
+ irq = RALINK_INT_PCIE0;
+ } else {
+ dev_err(&dev->dev, "no irq found - bus=0x%x, slot = 0x%x\n",
+ dev->bus->number, slot);
+ return 0;
+ }
+ dev_err(&dev->dev, "card - bus=0x%x, slot = 0x%x irq=%d\n",
+ dev->bus->number, slot, irq);
+
+ /* configure the cache line size to 0x14 */
+ pci_write_config_byte(dev, PCI_CACHE_LINE_SIZE, 0x14);
+
+ /* configure latency timer to 0xff */
+ pci_write_config_byte(dev, PCI_LATENCY_TIMER, 0xff);
+ pci_read_config_word(dev, PCI_COMMAND, &cmd);
+
+ /* setup the slot */
+ cmd = cmd | PCI_COMMAND_MASTER | PCI_COMMAND_IO | PCI_COMMAND_MEMORY;
+ pci_write_config_word(dev, PCI_COMMAND, cmd);
+ pci_write_config_byte(dev, PCI_INTERRUPT_LINE, dev->irq);
+
+ return irq;
+}
+
+int pcibios_plat_dev_init(struct pci_dev *dev)
+{
+ return 0;
+}
+
+static const struct of_device_id mt7620_pci_ids[] = {
+ { .compatible = "mediatek,mt7620-pci" },
+ {},
+};
+MODULE_DEVICE_TABLE(of, mt7620_pci_ids);
+
+static struct platform_driver mt7620_pci_driver = {
+ .probe = mt7620_pci_probe,
+ .driver = {
+ .name = "mt7620-pci",
+ .owner = THIS_MODULE,
+ .of_match_table = of_match_ptr(mt7620_pci_ids),
+ },
+};
+
+static int __init mt7620_pci_init(void)
+{
+ return platform_driver_register(&mt7620_pci_driver);
+}
+
+arch_initcall(mt7620_pci_init);
diff --git a/arch/mips/ralink/Kconfig b/arch/mips/ralink/Kconfig
index 016d26e..813826a 100644
--- a/arch/mips/ralink/Kconfig
+++ b/arch/mips/ralink/Kconfig
@@ -38,6 +38,7 @@ choice
config SOC_MT7620
bool "MT7620/8"
+ select HW_HAS_PCI
config SOC_MT7621
bool "MT7621"
--
1.7.10.4
