[PATCH 2/4] PCI: add driver for Cortina Gemini Host Bridge

Linus Walleij
2017-01-28T20:49:34Z

This adds a host bridge driver for the Cortina Systems Gemini
SoC (SL3516) PCI Host Bridge.

This code is inspired by the out-of-tree OpenWRT patch and
then extensively rewritten for device tree and using the modern
helpers to cut down and modernize the code to all new PCI
frameworks.

Tested on the ITian Square One SQ201 NAS with the following
result in the boot log (trimmed to relevant parts):

OF: PCI: host bridge /pci@50000000 ranges:
OF: PCI: IO 0x50000000..0x500fffff -> 0x00000000
OF: PCI: MEM 0x58000000..0x5fffffff -> 0x58000000
gemini-pci 50000000.pci: PCI host bridge to bus 0000:00
pci_bus 0000:00: root bus resource [bus 00]
pci_bus 0000:00: root bus resource [io 0x0000-0xfffff]
pci_bus 0000:00: root bus resource [mem 0x58000000-0x5fffffff]
pci 0000:00:00.0: [159b:4321] type 00 class 0x060000
pci 0000:00:09.0: [1106:3038] type 00 class 0x0c0300
pci 0000:00:09.0: reg 0x20: [io 0xfce0-0xfcff]
pci 0000:00:09.0: supports D1 D2
pci 0000:00:09.0: PME# supported from D0 D1 D2 D3hot D3cold
pci 0000:00:09.1: [1106:3038] type 00 class 0x0c0300
pci 0000:00:09.1: reg 0x20: [io 0xfce0-0xfcff]
pci 0000:00:09.1: supports D1 D2
pci 0000:00:09.1: PME# supported from D0 D1 D2 D3hot D3cold
pci 0000:00:09.2: [1106:3104] type 00 class 0x0c0320
pci 0000:00:09.2: reg 0x10: [mem 0x00000000-0x000000ff]
pci 0000:00:09.2: supports D1 D2
pci 0000:00:09.2: PME# supported from D0 D1 D2 D3hot D3cold
pci 0000:00:0c.0: [1814:0301] type 00 class 0x028000
pci 0000:00:0c.0: reg 0x10: [mem 0x58000000-0x58007fff]
PCI: bus0: Fast back to back transfers disabled
gemini-pci 50000000.pci: clear all IRQs
gemini-pci 50000000.pci: setting up PCI DMA
pci 0000:00:00.0: of_irq_parse_pci() failed with rc=-22
pci 0000:00:0c.0: BAR 0: assigned [mem 0x58000000-0x58007fff]
pci 0000:00:09.2: BAR 0: assigned [mem 0x58008000-0x580080ff]
pci 0000:00:09.0: BAR 4: assigned [io 0x0400-0x041f]
pci 0000:00:09.1: BAR 4: assigned [io 0x0420-0x043f]
pci 0000:00:09.0: enabling device (0140 -> 0141)
pci 0000:00:09.0: HCRESET not completed yet!
pci 0000:00:09.1: enabling device (0140 -> 0141)
pci 0000:00:09.1: HCRESET not completed yet!
pci 0000:00:09.2: enabling device (0140 -> 0142)
ieee80211 phy0: rt2x00_set_chip: Info - Chipset detected - rt: 2561, rf: 0003, rev: 000c
ieee80211 phy0: Selected rate control algorithm 'minstrel_ht'
ehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver
ehci-pci: EHCI PCI platform driver
ehci-pci 0000:00:09.2: EHCI Host Controller
ehci-pci 0000:00:09.2: new USB bus registered, assigned bus number 1
ehci-pci 0000:00:09.2: irq 146, io mem 0x58008000
ehci-pci 0000:00:09.2: USB 2.0 started, EHCI 1.00
hub 1-0:1.0: USB hub found
hub 1-0:1.0: 4 ports detected
uhci_hcd: USB Universal Host Controller Interface driver
uhci_hcd 0000:00:09.0: UHCI Host Controller
uhci_hcd 0000:00:09.0: new USB bus registered, assigned bus number 2
uhci_hcd 0000:00:09.0: HCRESET not completed yet!
uhci_hcd 0000:00:09.0: irq 144, io base 0x00000400
hub 2-0:1.0: USB hub found
hub 2-0:1.0: config failed, hub doesn't have any ports! (err -19)
uhci_hcd 0000:00:09.1: UHCI Host Controller
uhci_hcd 0000:00:09.1: new USB bus registered, assigned bus number 3
uhci_hcd 0000:00:09.1: HCRESET not completed yet!
uhci_hcd 0000:00:09.1: irq 145, io base 0x00000420
hub 3-0:1.0: USB hub found
hub 3-0:1.0: config failed, hub doesn't have any ports! (err -19)
usb 1-1: new high-speed USB device number 2 using ehci-pci
usb-storage 1-1:1.0: USB Mass Storage device detected
scsi host0: usb-storage 1-1:1.0
scsi 0:0:0:0: Direct-Access USB Flash Disk 1.00 PQ: 0 ANSI: 2
sd 0:0:0:0: [sda] 7900336 512-byte logical blocks: (4.04 GB/3.77 GiB)
sd 0:0:0:0: [sda] Write Protect is off
sd 0:0:0:0: [sda] Mode Sense: 0b 00 00 08
sd 0:0:0:0: [sda] No Caching mode page found
sd 0:0:0:0: [sda] Assuming drive cache: write through
sda: sda1 sda2 sda3
sd 0:0:0:0: [sda] Attached SCSI removable disk

$ lspci
00:00.0 Class 0600: 159b:4321
00:09.2 Class 0c03: 1106:3104
00:09.0 Class 0c03: 1106:3038
00:09.1 Class 0c03: 1106:3038
00:0c.0 Class 0280: 1814:0301

cat /proc/interrupts
CPU0
19: 0 GEMINI 3 Level watchdog bark
30: 4943 GEMINI 14 Edge Gemini Timer Tick
33: 0 GEMINI 17 Level 45000000.rtc
34: 651 GEMINI 18 Level serial
66: 0 GPIO 18 Edge factory reset
144: 0 PCI 0 Edge uhci_hcd:usb2
145: 0 PCI 1 Edge uhci_hcd:usb3
146: 160 PCI 2 Edge ehci_hcd:usb1

Well the EHCI USB hub works fine, I can mount and manage
files and the IRQs just keep ticking up.

Cc: Janos Laube <janos.dev@gmail.com>
Cc: Paulius Zaleckas <paulius.zaleckas@gmail.com>
Cc: Hans Ulli Kroll <ulli.kroll@googlemail.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
This can be merged to the PCI tree whenever it is considered
fine for inclusion.
---
drivers/pci/host/Kconfig | 7 +
drivers/pci/host/Makefile | 1 +
drivers/pci/host/pci-gemini.c | 375 ++++++++++++++++++++++++++++++++++++++++++
3 files changed, 383 insertions(+)
create mode 100644 drivers/pci/host/pci-gemini.c

diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig
index 898d2c48239c..e29c2caf3492 100644
--- a/drivers/pci/host/Kconfig
+++ b/drivers/pci/host/Kconfig
@@ -60,6 +60,13 @@ config PCI_EXYNOS
select PCIEPORTBUS
select PCIE_DW

+config PCI_GEMINI
+ bool "Cortina Gemini SL351x PCI roller"
+ depends on ARCH_GEMINI
+ depends on ARM
+ depends on OF
+ default ARCH_GEMINI
+
config PCI_IMX6
bool "Freescale i.MX6 PCIe controller"
depends on SOC_IMX6Q
diff --git a/drivers/pci/host/Makefile b/drivers/pci/host/Makefile
index bfe3179ae74c..8f007fe7a19d 100644
--- a/drivers/pci/host/Makefile
+++ b/drivers/pci/host/Makefile
@@ -2,6 +2,7 @@ obj-$(CONFIG_PCIE_DW) += pcie-designware.o
obj-$(CONFIG_PCIE_DW_PLAT) += pcie-designware-plat.o
obj-$(CONFIG_PCI_DRA7XX) += pci-dra7xx.o
obj-$(CONFIG_PCI_EXYNOS) += pci-exynos.o
+obj-$(CONFIG_PCI_GEMINI) += pci-gemini.o
obj-$(CONFIG_PCI_IMX6) += pci-imx6.o
obj-$(CONFIG_PCI_HYPERV) += pci-hyperv.o
obj-$(CONFIG_PCI_MVEBU) += pci-mvebu.o
diff --git a/drivers/pci/host/pci-gemini.c b/drivers/pci/host/pci-gemini.c
new file mode 100644
index 000000000000..7051dd992114
--- /dev/null
+++ b/drivers/pci/host/pci-gemini.c
@@ -0,0 +1,375 @@
+/*
+ * Support for Gemini PCI Controller
+ *
+ * Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org>
+ *
+ * Based on the out-of-tree OpenWRT patch:
+ * Copyright (C) 2009 Janos Laube <janos.dev@gmail.com>
+ * Copyright (C) 2009 Paulius Zaleckas <paulius.zaleckas@teltonika.lt>
+ * Based on SL2312 PCI controller code
+ * Storlink (C) 2003
+ */
+
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/of_address.h>
+#include <linux/of_pci.h>
+#include <linux/pci.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/irqdomain.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/bitops.h>
+#include <linux/irq.h>
+#include <linux/spinlock.h>
+
+#define GEMINI_PCI_IOSIZE_1M 0x0000
+
+#define GEMINI_PCI_PMC 0x40
+#define GEMINI_PCI_PMCSR 0x44
+#define GEMINI_PCI_CTRL1 0x48
+#define GEMINI_PCI_CTRL2 0x4C
+#define GEMINI_PCI_MEM1_BASE_SIZE 0x50
+#define GEMINI_PCI_MEM2_BASE_SIZE 0x54
+#define GEMINI_PCI_MEM3_BASE_SIZE 0x58
+
+#define PCI_CTRL2_INTSTS_SHIFT 28
+#define PCI_CTRL2_INTMASK_SHIFT 22
+
+#define GEMINI_PCI_DMA_MASK 0xFFF00000
+#define GEMINI_PCI_DMA_MEM1_BASE 0x00000000
+#define GEMINI_PCI_DMA_MEM2_BASE 0x00000000
+#define GEMINI_PCI_DMA_MEM3_BASE 0x00000000
+#define GEMINI_PCI_DMA_MEM1_SIZE 7
+#define GEMINI_PCI_DMA_MEM2_SIZE 6
+#define GEMINI_PCI_DMA_MEM3_SIZE 6
+
+#define PCI_CONF_ENABLE BIT(31)
+#define PCI_CONF_WHERE(r) ((r) & 0xFC)
+#define PCI_CONF_BUS(b) (((b) & 0xFF) << 16)
+#define PCI_CONF_DEVICE(d) (((d) & 0x1F) << 11)
+#define PCI_CONF_FUNCTION(f) (((f) & 0x07) << 8)
+
+#define PCI_IOSIZE 0x00
+#define PCI_PROT 0x04
+#define PCI_CTRL 0x08
+#define PCI_SOFTRST 0x10
+#define PCI_CONFIG 0x28
+#define PCI_DATA 0x2C
+
+struct gemini_pci {
+ struct device *dev;
+ void __iomem *base;
+ struct irq_domain *irqdomain;
+ spinlock_t lock;
+ struct pci_bus *bus;
+};
+
+static int gemini_pci_read_config(struct pci_bus *bus, unsigned int fn,
+ int config, int size, u32 *value)
+{
+ struct gemini_pci *p = bus->sysdata;
+ unsigned long irq_flags;
+
+ spin_lock_irqsave(&p->lock, irq_flags);
+
+ writel(PCI_CONF_BUS(bus->number) |
+ PCI_CONF_DEVICE(PCI_SLOT(fn)) |
+ PCI_CONF_FUNCTION(PCI_FUNC(fn)) |
+ PCI_CONF_WHERE(config) |
+ PCI_CONF_ENABLE,
+ p->base + PCI_CONFIG);
+
+ *value = readl(p->base + PCI_DATA);
+
+ if (size == 1)
+ *value = (*value >> (8 * (config & 3))) & 0xFF;
+ else if (size == 2)
+ *value = (*value >> (8 * (config & 3))) & 0xFFFF;
+
+ spin_unlock_irqrestore(&p->lock, irq_flags);
+
+ dev_dbg(&bus->dev,
+ "[read] slt: %.2d, fnc: %d, cnf: 0x%.2X, val (%d bytes): 0x%.8X\n",
+ PCI_SLOT(fn), PCI_FUNC(fn), config, size, *value);
+
+ return PCIBIOS_SUCCESSFUL;
+}
+
+static int gemini_pci_write_config(struct pci_bus *bus, unsigned int fn,
+ int config, int size, u32 value)
+{
+ struct gemini_pci *p = bus->sysdata;
+ unsigned long irq_flags = 0;
+ int ret = PCIBIOS_SUCCESSFUL;
+
+ dev_dbg(&bus->dev,
+ "[write] slt: %.2d, fnc: %d, cnf: 0x%.2X, val (%d bytes): 0x%.8X\n",
+ PCI_SLOT(fn), PCI_FUNC(fn), config, size, value);
+
+ spin_lock_irqsave(&p->lock, irq_flags);
+
+ writel(PCI_CONF_BUS(bus->number) |
+ PCI_CONF_DEVICE(PCI_SLOT(fn)) |
+ PCI_CONF_FUNCTION(PCI_FUNC(fn)) |
+ PCI_CONF_WHERE(config) |
+ PCI_CONF_ENABLE,
+ p->base + PCI_CONFIG);
+
+ switch (size) {
+ case 4:
+ writel(value, p->base + PCI_DATA);
+ break;
+ case 2:
+ writew(value, p->base + PCI_DATA + (config & 3));
+ break;
+ case 1:
+ writeb(value, p->base + PCI_DATA + (config & 3));
+ break;
+ default:
+ ret = PCIBIOS_BAD_REGISTER_NUMBER;
+ }
+
+ spin_unlock_irqrestore(&p->lock, irq_flags);
+
+ return ret;
+}
+
+static struct pci_ops gemini_pci_ops = {
+ .read = gemini_pci_read_config,
+ .write = gemini_pci_write_config,
+};
+
+static void gemini_pci_ack_irq(struct irq_data *d)
+{
+ struct gemini_pci *p = irq_data_get_irq_chip_data(d);
+ unsigned int reg;
+
+ gemini_pci_read_config(p->bus, 0, GEMINI_PCI_CTRL2, 4, &reg);
+ reg &= ~(0xF << PCI_CTRL2_INTSTS_SHIFT);
+ reg |= BIT(irqd_to_hwirq(d) + PCI_CTRL2_INTSTS_SHIFT);
+ gemini_pci_write_config(p->bus, 0, GEMINI_PCI_CTRL2, 4, reg);
+}
+
+static void gemini_pci_mask_irq(struct irq_data *d)
+{
+ struct gemini_pci *p = irq_data_get_irq_chip_data(d);
+ unsigned int reg;
+
+ gemini_pci_read_config(p->bus, 0, GEMINI_PCI_CTRL2, 4, &reg);
+ reg &= ~((0xF << PCI_CTRL2_INTSTS_SHIFT)
+ | BIT(irqd_to_hwirq(d) + PCI_CTRL2_INTMASK_SHIFT));
+ gemini_pci_write_config(p->bus, 0, GEMINI_PCI_CTRL2, 4, reg);
+}
+
+static void gemini_pci_unmask_irq(struct irq_data *d)
+{
+ struct gemini_pci *p = irq_data_get_irq_chip_data(d);
+ unsigned int reg;
+
+ gemini_pci_read_config(p->bus, 0, GEMINI_PCI_CTRL2, 4, &reg);
+ reg &= ~(0xF << PCI_CTRL2_INTSTS_SHIFT);
+ reg |= BIT(irqd_to_hwirq(d) + PCI_CTRL2_INTMASK_SHIFT);
+ gemini_pci_write_config(p->bus, 0, GEMINI_PCI_CTRL2, 4, reg);
+}
+
+static void gemini_pci_irq_handler(struct irq_desc *desc)
+{
+ struct gemini_pci *p = irq_desc_get_handler_data(desc);
+ struct irq_chip *irqchip = irq_desc_get_chip(desc);
+ unsigned int irq_stat, reg, i;
+
+ gemini_pci_read_config(p->bus, 0, GEMINI_PCI_CTRL2, 4, &reg);
+ irq_stat = reg >> PCI_CTRL2_INTSTS_SHIFT;
+
+ chained_irq_enter(irqchip, desc);
+
+ for (i = 0; i < 4; i++) {
+ if ((irq_stat & BIT(i)) == 0)
+ continue;
+ generic_handle_irq(irq_find_mapping(p->irqdomain, i));
+ }
+
+ chained_irq_exit(irqchip, desc);
+}
+
+static struct irq_chip gemini_pci_irq_chip = {
+ .name = "PCI",
+ .irq_ack = gemini_pci_ack_irq,
+ .irq_mask = gemini_pci_mask_irq,
+ .irq_unmask = gemini_pci_unmask_irq,
+};
+
+static int gemini_pci_irq_map(struct irq_domain *domain, unsigned int irq,
+ irq_hw_number_t hwirq)
+{
+ irq_set_chip_and_handler(irq, &gemini_pci_irq_chip, handle_level_irq);
+ irq_set_chip_data(irq, domain->host_data);
+
+ return 0;
+}
+
+static const struct irq_domain_ops gemini_pci_irqdomain_ops = {
+ .map = gemini_pci_irq_map,
+};
+
+static int gemini_pci_setup_irq(struct gemini_pci *p, int irq)
+{
+ struct device_node *intc = of_get_next_child(p->dev->of_node, NULL);
+ int i;
+
+ if (!intc) {
+ dev_err(p->dev, "missing child interrupt-controller node\n");
+ return -EINVAL;
+ }
+
+ p->irqdomain = irq_domain_add_linear(intc, 4,
+ &gemini_pci_irqdomain_ops,
+ p);
+ if (!p->irqdomain) {
+ dev_err(p->dev, "failed to create Gemini PCI IRQ domain\n");
+ return -EINVAL;
+ }
+
+ irq_set_chained_handler_and_data(irq, gemini_pci_irq_handler, p);
+
+ for (i = 0; i < 4; i++)
+ irq_create_mapping(p->irqdomain, i);
+
+ return 0;
+}
+
+static int gemini_pci_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct resource *regs;
+ resource_size_t io_base;
+ struct resource_entry *win;
+ struct gemini_pci *p;
+ struct resource *mem;
+ struct resource *io;
+ struct pci_bus *bus;
+ int irq;
+ int ret;
+ u32 val;
+ LIST_HEAD(res);
+
+ p = devm_kzalloc(dev, sizeof(*p), GFP_KERNEL);
+ if (!p)
+ return -ENOMEM;
+
+ p->dev = dev;
+ spin_lock_init(&p->lock);
+
+ regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ p->base = devm_ioremap_resource(dev, regs);
+ if (IS_ERR(p->base))
+ return PTR_ERR(p->base);
+
+ ret = of_pci_get_host_bridge_resources(dev->of_node, 0, 0xff,
+ &res, &io_base);
+ if (ret)
+ return ret;
+
+ ret = devm_request_pci_bus_resources(dev, &res);
+ if (ret)
+ return ret;
+
+ /* No clue what these do */
+ pcibios_min_io = 0x100;
+ pcibios_min_mem = 0;
+
+ /* setup I/O space to 1MB size */
+ writel(GEMINI_PCI_IOSIZE_1M, p->base + PCI_IOSIZE);
+
+ /* setup hostbridge */
+ val = readl(p->base + PCI_CTRL);
+ val |= PCI_COMMAND_IO;
+ val |= PCI_COMMAND_MEMORY;
+ val |= PCI_COMMAND_MASTER;
+ writel(val, p->base + PCI_CTRL);
+
+ /* Get the I/O and memory ranges from DT */
+ resource_list_for_each_entry(win, &res) {
+ switch (resource_type(win->res)) {
+ case IORESOURCE_IO:
+ io = win->res;
+ io->name = "Gemini PCI I/O";
+ ret = pci_remap_iospace(io, io_base);
+ if (ret) {
+ dev_warn(dev, "error %d: failed to map resource %pR\n",
+ ret, io);
+ continue;
+ }
+ break;
+ case IORESOURCE_MEM:
+ mem = win->res;
+ mem->name = "Gemini PCI MEM";
+ break;
+ case IORESOURCE_BUS:
+ break;
+ default:
+ break;
+ }
+ }
+
+ bus = pci_scan_root_bus(&pdev->dev, 0, &gemini_pci_ops, p, &res);
+ if (!bus)
+ return -ENOMEM;
+ p->bus = bus;
+
+ dev_info(dev, "clear all IRQs\n");
+
+ /* Mask and clear all interrupts */
+ gemini_pci_write_config(bus, 0, GEMINI_PCI_CTRL2 + 2, 2, 0xF000);
+
+ /* IRQ - all PCI IRQs cascade off this one */
+ irq = platform_get_irq(pdev, 0);
+ if (!irq) {
+ dev_err(dev, "failed to get IRQ\n");
+ return -EINVAL;
+ }
+
+ ret = gemini_pci_setup_irq(p, irq);
+ if (ret) {
+ dev_err(dev, "failed to setup IRQ\n");
+ return ret;
+ }
+
+ dev_info(dev, "setting up PCI DMA\n");
+ val = (GEMINI_PCI_DMA_MEM1_BASE & GEMINI_PCI_DMA_MASK)
+ | (GEMINI_PCI_DMA_MEM1_SIZE << 16);
+ gemini_pci_write_config(bus, 0, GEMINI_PCI_MEM1_BASE_SIZE, 4, val);
+ val = (GEMINI_PCI_DMA_MEM2_BASE & GEMINI_PCI_DMA_MASK)
+ | (GEMINI_PCI_DMA_MEM2_SIZE << 16);
+ gemini_pci_write_config(bus, 0, GEMINI_PCI_MEM2_BASE_SIZE, 4, val);
+ val = (GEMINI_PCI_DMA_MEM3_BASE & GEMINI_PCI_DMA_MASK)
+ | (GEMINI_PCI_DMA_MEM3_SIZE << 16);
+ gemini_pci_write_config(bus, 0, GEMINI_PCI_MEM3_BASE_SIZE, 4, val);
+
+ pci_fixup_irqs(pci_common_swizzle, of_irq_parse_and_map_pci);
+ pci_bus_assign_resources(bus);
+ pci_assign_unassigned_bus_resources(bus);
+ pci_bus_add_devices(bus);
+ pci_free_resource_list(&res);
+
+ return 0;
+}
+
+static const struct of_device_id gemini_pci_of_match[] = {
+ {
+ .compatible = "cortina,gemini-pci",
+ },
+ {},
+};
+
+static struct platform_driver gemini_pci_driver = {
+ .driver = {
+ .name = "gemini-pci",
+ .of_match_table = of_match_ptr(gemini_pci_of_match),
+ },
+ .probe = gemini_pci_probe,
+};
+builtin_platform_driver(gemini_pci_driver);
--
2.9.3