diff options
Diffstat (limited to 'drivers/pci/host/pci-xgene.c')
| -rw-r--r-- | drivers/pci/host/pci-xgene.c | 531 |
1 files changed, 531 insertions, 0 deletions
diff --git a/drivers/pci/host/pci-xgene.c b/drivers/pci/host/pci-xgene.c new file mode 100644 index 000000000..ee082c036 --- /dev/null +++ b/drivers/pci/host/pci-xgene.c @@ -0,0 +1,531 @@ +/** + * APM X-Gene PCIe Driver + * + * Copyright (c) 2014 Applied Micro Circuits Corporation. + * + * Author: Tanmay Inamdar <tinamdar@apm.com>. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or (at your + * option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + */ +#include <linux/clk.h> +#include <linux/delay.h> +#include <linux/io.h> +#include <linux/jiffies.h> +#include <linux/memblock.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/of_irq.h> +#include <linux/of_pci.h> +#include <linux/pci.h> +#include <linux/platform_device.h> +#include <linux/slab.h> + +#define PCIECORE_CTLANDSTATUS 0x50 +#define PIM1_1L 0x80 +#define IBAR2 0x98 +#define IR2MSK 0x9c +#define PIM2_1L 0xa0 +#define IBAR3L 0xb4 +#define IR3MSKL 0xbc +#define PIM3_1L 0xc4 +#define OMR1BARL 0x100 +#define OMR2BARL 0x118 +#define OMR3BARL 0x130 +#define CFGBARL 0x154 +#define CFGBARH 0x158 +#define CFGCTL 0x15c +#define RTDID 0x160 +#define BRIDGE_CFG_0 0x2000 +#define BRIDGE_CFG_4 0x2010 +#define BRIDGE_STATUS_0 0x2600 + +#define LINK_UP_MASK 0x00000100 +#define AXI_EP_CFG_ACCESS 0x10000 +#define EN_COHERENCY 0xF0000000 +#define EN_REG 0x00000001 +#define OB_LO_IO 0x00000002 +#define XGENE_PCIE_VENDORID 0x10E8 +#define XGENE_PCIE_DEVICEID 0xE004 +#define SZ_1T (SZ_1G*1024ULL) +#define PIPE_PHY_RATE_RD(src) ((0xc000 & (u32)(src)) >> 0xe) + +struct xgene_pcie_port { + struct device_node *node; + struct device *dev; + struct clk *clk; + void __iomem *csr_base; + void __iomem *cfg_base; + unsigned long cfg_addr; + bool link_up; +}; + +static inline u32 pcie_bar_low_val(u32 addr, u32 flags) +{ + return (addr & PCI_BASE_ADDRESS_MEM_MASK) | flags; +} + +/* + * When the address bit [17:16] is 2'b01, the Configuration access will be + * treated as Type 1 and it will be forwarded to external PCIe device. + */ +static void __iomem *xgene_pcie_get_cfg_base(struct pci_bus *bus) +{ + struct xgene_pcie_port *port = bus->sysdata; + + if (bus->number >= (bus->primary + 1)) + return port->cfg_base + AXI_EP_CFG_ACCESS; + + return port->cfg_base; +} + +/* + * For Configuration request, RTDID register is used as Bus Number, + * Device Number and Function number of the header fields. + */ +static void xgene_pcie_set_rtdid_reg(struct pci_bus *bus, uint devfn) +{ + struct xgene_pcie_port *port = bus->sysdata; + unsigned int b, d, f; + u32 rtdid_val = 0; + + b = bus->number; + d = PCI_SLOT(devfn); + f = PCI_FUNC(devfn); + + if (!pci_is_root_bus(bus)) + rtdid_val = (b << 8) | (d << 3) | f; + + writel(rtdid_val, port->csr_base + RTDID); + /* read the register back to ensure flush */ + readl(port->csr_base + RTDID); +} + +/* + * X-Gene PCIe port uses BAR0-BAR1 of RC's configuration space as + * the translation from PCI bus to native BUS. Entire DDR region + * is mapped into PCIe space using these registers, so it can be + * reached by DMA from EP devices. The BAR0/1 of bridge should be + * hidden during enumeration to avoid the sizing and resource allocation + * by PCIe core. + */ +static bool xgene_pcie_hide_rc_bars(struct pci_bus *bus, int offset) +{ + if (pci_is_root_bus(bus) && ((offset == PCI_BASE_ADDRESS_0) || + (offset == PCI_BASE_ADDRESS_1))) + return true; + + return false; +} + +static void __iomem *xgene_pcie_map_bus(struct pci_bus *bus, unsigned int devfn, + int offset) +{ + struct xgene_pcie_port *port = bus->sysdata; + + if ((pci_is_root_bus(bus) && devfn != 0) || !port->link_up || + xgene_pcie_hide_rc_bars(bus, offset)) + return NULL; + + xgene_pcie_set_rtdid_reg(bus, devfn); + return xgene_pcie_get_cfg_base(bus) + offset; +} + +static struct pci_ops xgene_pcie_ops = { + .map_bus = xgene_pcie_map_bus, + .read = pci_generic_config_read32, + .write = pci_generic_config_write32, +}; + +static u64 xgene_pcie_set_ib_mask(void __iomem *csr_base, u32 addr, + u32 flags, u64 size) +{ + u64 mask = (~(size - 1) & PCI_BASE_ADDRESS_MEM_MASK) | flags; + u32 val32 = 0; + u32 val; + + val32 = readl(csr_base + addr); + val = (val32 & 0x0000ffff) | (lower_32_bits(mask) << 16); + writel(val, csr_base + addr); + + val32 = readl(csr_base + addr + 0x04); + val = (val32 & 0xffff0000) | (lower_32_bits(mask) >> 16); + writel(val, csr_base + addr + 0x04); + + val32 = readl(csr_base + addr + 0x04); + val = (val32 & 0x0000ffff) | (upper_32_bits(mask) << 16); + writel(val, csr_base + addr + 0x04); + + val32 = readl(csr_base + addr + 0x08); + val = (val32 & 0xffff0000) | (upper_32_bits(mask) >> 16); + writel(val, csr_base + addr + 0x08); + + return mask; +} + +static void xgene_pcie_linkup(struct xgene_pcie_port *port, + u32 *lanes, u32 *speed) +{ + void __iomem *csr_base = port->csr_base; + u32 val32; + + port->link_up = false; + val32 = readl(csr_base + PCIECORE_CTLANDSTATUS); + if (val32 & LINK_UP_MASK) { + port->link_up = true; + *speed = PIPE_PHY_RATE_RD(val32); + val32 = readl(csr_base + BRIDGE_STATUS_0); + *lanes = val32 >> 26; + } +} + +static int xgene_pcie_init_port(struct xgene_pcie_port *port) +{ + int rc; + + port->clk = clk_get(port->dev, NULL); + if (IS_ERR(port->clk)) { + dev_err(port->dev, "clock not available\n"); + return -ENODEV; + } + + rc = clk_prepare_enable(port->clk); + if (rc) { + dev_err(port->dev, "clock enable failed\n"); + return rc; + } + + return 0; +} + +static int xgene_pcie_map_reg(struct xgene_pcie_port *port, + struct platform_device *pdev) +{ + struct resource *res; + + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "csr"); + port->csr_base = devm_ioremap_resource(port->dev, res); + if (IS_ERR(port->csr_base)) + return PTR_ERR(port->csr_base); + + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "cfg"); + port->cfg_base = devm_ioremap_resource(port->dev, res); + if (IS_ERR(port->cfg_base)) + return PTR_ERR(port->cfg_base); + port->cfg_addr = res->start; + + return 0; +} + +static void xgene_pcie_setup_ob_reg(struct xgene_pcie_port *port, + struct resource *res, u32 offset, + u64 cpu_addr, u64 pci_addr) +{ + void __iomem *base = port->csr_base + offset; + resource_size_t size = resource_size(res); + u64 restype = resource_type(res); + u64 mask = 0; + u32 min_size; + u32 flag = EN_REG; + + if (restype == IORESOURCE_MEM) { + min_size = SZ_128M; + } else { + min_size = 128; + flag |= OB_LO_IO; + } + + if (size >= min_size) + mask = ~(size - 1) | flag; + else + dev_warn(port->dev, "res size 0x%llx less than minimum 0x%x\n", + (u64)size, min_size); + + writel(lower_32_bits(cpu_addr), base); + writel(upper_32_bits(cpu_addr), base + 0x04); + writel(lower_32_bits(mask), base + 0x08); + writel(upper_32_bits(mask), base + 0x0c); + writel(lower_32_bits(pci_addr), base + 0x10); + writel(upper_32_bits(pci_addr), base + 0x14); +} + +static void xgene_pcie_setup_cfg_reg(void __iomem *csr_base, u64 addr) +{ + writel(lower_32_bits(addr), csr_base + CFGBARL); + writel(upper_32_bits(addr), csr_base + CFGBARH); + writel(EN_REG, csr_base + CFGCTL); +} + +static int xgene_pcie_map_ranges(struct xgene_pcie_port *port, + struct list_head *res, + resource_size_t io_base) +{ + struct resource_entry *window; + struct device *dev = port->dev; + int ret; + + resource_list_for_each_entry(window, res) { + struct resource *res = window->res; + u64 restype = resource_type(res); + + dev_dbg(port->dev, "%pR\n", res); + + switch (restype) { + case IORESOURCE_IO: + xgene_pcie_setup_ob_reg(port, res, OMR3BARL, io_base, + res->start - window->offset); + ret = pci_remap_iospace(res, io_base); + if (ret < 0) + return ret; + break; + case IORESOURCE_MEM: + xgene_pcie_setup_ob_reg(port, res, OMR1BARL, res->start, + res->start - window->offset); + break; + case IORESOURCE_BUS: + break; + default: + dev_err(dev, "invalid resource %pR\n", res); + return -EINVAL; + } + } + xgene_pcie_setup_cfg_reg(port->csr_base, port->cfg_addr); + + return 0; +} + +static void xgene_pcie_setup_pims(void *addr, u64 pim, u64 size) +{ + writel(lower_32_bits(pim), addr); + writel(upper_32_bits(pim) | EN_COHERENCY, addr + 0x04); + writel(lower_32_bits(size), addr + 0x10); + writel(upper_32_bits(size), addr + 0x14); +} + +/* + * X-Gene PCIe support maximum 3 inbound memory regions + * This function helps to select a region based on size of region + */ +static int xgene_pcie_select_ib_reg(u8 *ib_reg_mask, u64 size) +{ + if ((size > 4) && (size < SZ_16M) && !(*ib_reg_mask & (1 << 1))) { + *ib_reg_mask |= (1 << 1); + return 1; + } + + if ((size > SZ_1K) && (size < SZ_1T) && !(*ib_reg_mask & (1 << 0))) { + *ib_reg_mask |= (1 << 0); + return 0; + } + + if ((size > SZ_1M) && (size < SZ_1T) && !(*ib_reg_mask & (1 << 2))) { + *ib_reg_mask |= (1 << 2); + return 2; + } + + return -EINVAL; +} + +static void xgene_pcie_setup_ib_reg(struct xgene_pcie_port *port, + struct of_pci_range *range, u8 *ib_reg_mask) +{ + void __iomem *csr_base = port->csr_base; + void __iomem *cfg_base = port->cfg_base; + void *bar_addr; + void *pim_addr; + u64 cpu_addr = range->cpu_addr; + u64 pci_addr = range->pci_addr; + u64 size = range->size; + u64 mask = ~(size - 1) | EN_REG; + u32 flags = PCI_BASE_ADDRESS_MEM_TYPE_64; + u32 bar_low; + int region; + + region = xgene_pcie_select_ib_reg(ib_reg_mask, range->size); + if (region < 0) { + dev_warn(port->dev, "invalid pcie dma-range config\n"); + return; + } + + if (range->flags & IORESOURCE_PREFETCH) + flags |= PCI_BASE_ADDRESS_MEM_PREFETCH; + + bar_low = pcie_bar_low_val((u32)cpu_addr, flags); + switch (region) { + case 0: + xgene_pcie_set_ib_mask(csr_base, BRIDGE_CFG_4, flags, size); + bar_addr = cfg_base + PCI_BASE_ADDRESS_0; + writel(bar_low, bar_addr); + writel(upper_32_bits(cpu_addr), bar_addr + 0x4); + pim_addr = csr_base + PIM1_1L; + break; + case 1: + bar_addr = csr_base + IBAR2; + writel(bar_low, bar_addr); + writel(lower_32_bits(mask), csr_base + IR2MSK); + pim_addr = csr_base + PIM2_1L; + break; + case 2: + bar_addr = csr_base + IBAR3L; + writel(bar_low, bar_addr); + writel(upper_32_bits(cpu_addr), bar_addr + 0x4); + writel(lower_32_bits(mask), csr_base + IR3MSKL); + writel(upper_32_bits(mask), csr_base + IR3MSKL + 0x4); + pim_addr = csr_base + PIM3_1L; + break; + } + + xgene_pcie_setup_pims(pim_addr, pci_addr, ~(size - 1)); +} + +static int pci_dma_range_parser_init(struct of_pci_range_parser *parser, + struct device_node *node) +{ + const int na = 3, ns = 2; + int rlen; + + parser->node = node; + parser->pna = of_n_addr_cells(node); + parser->np = parser->pna + na + ns; + + parser->range = of_get_property(node, "dma-ranges", &rlen); + if (!parser->range) + return -ENOENT; + parser->end = parser->range + rlen / sizeof(__be32); + + return 0; +} + +static int xgene_pcie_parse_map_dma_ranges(struct xgene_pcie_port *port) +{ + struct device_node *np = port->node; + struct of_pci_range range; + struct of_pci_range_parser parser; + struct device *dev = port->dev; + u8 ib_reg_mask = 0; + + if (pci_dma_range_parser_init(&parser, np)) { + dev_err(dev, "missing dma-ranges property\n"); + return -EINVAL; + } + + /* Get the dma-ranges from DT */ + for_each_of_pci_range(&parser, &range) { + u64 end = range.cpu_addr + range.size - 1; + + dev_dbg(port->dev, "0x%08x 0x%016llx..0x%016llx -> 0x%016llx\n", + range.flags, range.cpu_addr, end, range.pci_addr); + xgene_pcie_setup_ib_reg(port, &range, &ib_reg_mask); + } + return 0; +} + +/* clear BAR configuration which was done by firmware */ +static void xgene_pcie_clear_config(struct xgene_pcie_port *port) +{ + int i; + + for (i = PIM1_1L; i <= CFGCTL; i += 4) + writel(0x0, port->csr_base + i); +} + +static int xgene_pcie_setup(struct xgene_pcie_port *port, + struct list_head *res, + resource_size_t io_base) +{ + u32 val, lanes = 0, speed = 0; + int ret; + + xgene_pcie_clear_config(port); + + /* setup the vendor and device IDs correctly */ + val = (XGENE_PCIE_DEVICEID << 16) | XGENE_PCIE_VENDORID; + writel(val, port->csr_base + BRIDGE_CFG_0); + + ret = xgene_pcie_map_ranges(port, res, io_base); + if (ret) + return ret; + + ret = xgene_pcie_parse_map_dma_ranges(port); + if (ret) + return ret; + + xgene_pcie_linkup(port, &lanes, &speed); + if (!port->link_up) + dev_info(port->dev, "(rc) link down\n"); + else + dev_info(port->dev, "(rc) x%d gen-%d link up\n", + lanes, speed + 1); + return 0; +} + +static int xgene_pcie_probe_bridge(struct platform_device *pdev) +{ + struct device_node *dn = pdev->dev.of_node; + struct xgene_pcie_port *port; + resource_size_t iobase = 0; + struct pci_bus *bus; + int ret; + LIST_HEAD(res); + + port = devm_kzalloc(&pdev->dev, sizeof(*port), GFP_KERNEL); + if (!port) + return -ENOMEM; + port->node = of_node_get(pdev->dev.of_node); + port->dev = &pdev->dev; + + ret = xgene_pcie_map_reg(port, pdev); + if (ret) + return ret; + + ret = xgene_pcie_init_port(port); + if (ret) + return ret; + + ret = of_pci_get_host_bridge_resources(dn, 0, 0xff, &res, &iobase); + if (ret) + return ret; + + ret = xgene_pcie_setup(port, &res, iobase); + if (ret) + return ret; + + bus = pci_create_root_bus(&pdev->dev, 0, + &xgene_pcie_ops, port, &res); + if (!bus) + return -ENOMEM; + + pci_scan_child_bus(bus); + pci_assign_unassigned_bus_resources(bus); + pci_bus_add_devices(bus); + + platform_set_drvdata(pdev, port); + return 0; +} + +static const struct of_device_id xgene_pcie_match_table[] = { + {.compatible = "apm,xgene-pcie",}, + {}, +}; + +static struct platform_driver xgene_pcie_driver = { + .driver = { + .name = "xgene-pcie", + .of_match_table = of_match_ptr(xgene_pcie_match_table), + }, + .probe = xgene_pcie_probe_bridge, +}; +module_platform_driver(xgene_pcie_driver); + +MODULE_AUTHOR("Tanmay Inamdar <tinamdar@apm.com>"); +MODULE_DESCRIPTION("APM X-Gene PCIe driver"); +MODULE_LICENSE("GPL v2"); |