diff options
Diffstat (limited to 'target/linux/oxnas/files-5.4/drivers/pci/controller/pcie-oxnas.c')
-rw-r--r-- | target/linux/oxnas/files-5.4/drivers/pci/controller/pcie-oxnas.c | 674 |
1 files changed, 674 insertions, 0 deletions
diff --git a/target/linux/oxnas/files-5.4/drivers/pci/controller/pcie-oxnas.c b/target/linux/oxnas/files-5.4/drivers/pci/controller/pcie-oxnas.c new file mode 100644 index 0000000000..f2145e31b5 --- /dev/null +++ b/target/linux/oxnas/files-5.4/drivers/pci/controller/pcie-oxnas.c @@ -0,0 +1,674 @@ +/* + * PCIe driver for PLX NAS782X SoCs + * + * Author: Ma Haijun <mahaijuns@gmail.com> + * + * This file is licensed under the terms of the GNU General Public + * License version 2. This program is licensed "as is" without any + * warranty of any kind, whether express or implied. + */ + +#include <linux/kernel.h> +#include <linux/pci.h> +#include <linux/clk.h> +#include <linux/module.h> +#include <linux/mbus.h> +#include <linux/mfd/syscon.h> +#include <linux/slab.h> +#include <linux/platform_device.h> +#include <linux/of_address.h> +#include <linux/of_device.h> +#include <linux/of_gpio.h> +#include <linux/of_irq.h> +#include <linux/of_pci.h> +#include <linux/of_platform.h> +#include <linux/gpio.h> +#include <linux/delay.h> +#include <linux/clk.h> +#include <linux/phy.h> +#include <linux/phy/phy.h> +#include <linux/regmap.h> +#include <linux/reset.h> +#include <linux/io.h> +#include <linux/sizes.h> + +#include "../pci.h" + +#define SYS_CTRL_HCSL_CTRL_REGOFFSET 0x114 + +static inline void oxnas_register_clear_mask(void __iomem *p, unsigned mask) +{ + u32 val = readl_relaxed(p); + + val &= ~mask; + writel_relaxed(val, p); +} + +static inline void oxnas_register_set_mask(void __iomem *p, unsigned mask) +{ + u32 val = readl_relaxed(p); + + val |= mask; + writel_relaxed(val, p); +} + +static inline void oxnas_register_value_mask(void __iomem *p, + unsigned mask, unsigned new_value) +{ + /* TODO sanity check mask & new_value = new_value */ + u32 val = readl_relaxed(p); + + val &= ~mask; + val |= new_value; + writel_relaxed(val, p); +} + +#define VERSION_ID_MAGIC 0x082510b5 +#define LINK_UP_TIMEOUT_SECONDS 1 +#define NUM_CONTROLLERS 1 + +enum { + PCIE_DEVICE_TYPE_MASK = 0x0F, + PCIE_DEVICE_TYPE_ENDPOINT = 0, + PCIE_DEVICE_TYPE_LEGACY_ENDPOINT = 1, + PCIE_DEVICE_TYPE_ROOT = 4, + + PCIE_LTSSM = BIT(4), + PCIE_READY_ENTR_L23 = BIT(9), + PCIE_LINK_UP = BIT(11), + PCIE_OBTRANS = BIT(12), +}; + +/* core config registers */ +enum { + PCI_CONFIG_VERSION_DEVICEID = 0, + PCI_CONFIG_COMMAND_STATUS = 4, +}; + +/* inbound config registers */ +enum { + IB_ADDR_XLATE_ENABLE = 0xFC, + + /* bits */ + ENABLE_IN_ADDR_TRANS = BIT(0), +}; + +/* outbound config registers, offset relative to PCIE_POM0_MEM_ADDR */ +enum { + PCIE_POM0_MEM_ADDR = 0, + PCIE_POM1_MEM_ADDR = 4, + PCIE_IN0_MEM_ADDR = 8, + PCIE_IN1_MEM_ADDR = 12, + PCIE_IN_IO_ADDR = 16, + PCIE_IN_CFG0_ADDR = 20, + PCIE_IN_CFG1_ADDR = 24, + PCIE_IN_MSG_ADDR = 28, + PCIE_IN0_MEM_LIMIT = 32, + PCIE_IN1_MEM_LIMIT = 36, + PCIE_IN_IO_LIMIT = 40, + PCIE_IN_CFG0_LIMIT = 44, + PCIE_IN_CFG1_LIMIT = 48, + PCIE_IN_MSG_LIMIT = 52, + PCIE_AHB_SLAVE_CTRL = 56, + + PCIE_SLAVE_BE_SHIFT = 22, +}; + +#define PCIE_SLAVE_BE(val) ((val) << PCIE_SLAVE_BE_SHIFT) +#define PCIE_SLAVE_BE_MASK PCIE_SLAVE_BE(0xF) + +struct oxnas_pcie_shared { + /* seems all access are serialized, no lock required */ + int refcount; +}; + +/* Structure representing one PCIe interfaces */ +struct oxnas_pcie { + void __iomem *cfgbase; + void __iomem *base; + void __iomem *inbound; + struct regmap *sys_ctrl; + unsigned int outbound_offset; + unsigned int pcie_ctrl_offset; + struct phy *phy; + int haslink; + struct platform_device *pdev; + struct resource io; + struct resource cfg; + struct resource pre_mem; /* prefetchable */ + struct resource non_mem; /* non-prefetchable */ + struct resource busn; /* max available bus numbers */ + int card_reset; /* gpio pin, optional */ + unsigned hcsl_en; /* hcsl pci enable bit */ + struct clk *clk; + struct clk *busclk; /* for pcie bus, actually the PLLB */ + void *private_data[1]; + spinlock_t lock; +}; + +static struct oxnas_pcie_shared pcie_shared = { + .refcount = 0, +}; + +static inline struct oxnas_pcie *sys_to_pcie(struct pci_sys_data *sys) +{ + return sys->private_data; +} + + +static inline void set_out_lanes(struct oxnas_pcie *pcie, unsigned lanes) +{ + regmap_update_bits(pcie->sys_ctrl, pcie->outbound_offset + PCIE_AHB_SLAVE_CTRL, + PCIE_SLAVE_BE_MASK, PCIE_SLAVE_BE(lanes)); + wmb(); +} + +static int oxnas_pcie_link_up(struct oxnas_pcie *pcie) +{ + unsigned long end; + unsigned int val; + + /* Poll for PCIE link up */ + end = jiffies + (LINK_UP_TIMEOUT_SECONDS * HZ); + while (!time_after(jiffies, end)) { + regmap_read(pcie->sys_ctrl, pcie->pcie_ctrl_offset, &val); + if (val & PCIE_LINK_UP) + return 1; + } + return 0; +} + +static void oxnas_pcie_setup_hw(struct oxnas_pcie *pcie) +{ + /* We won't have any inbound address translation. This allows PCI + * devices to access anywhere in the AHB address map. Might be regarded + * as a bit dangerous, but let's get things working before we worry + * about that + */ + oxnas_register_clear_mask(pcie->inbound + IB_ADDR_XLATE_ENABLE, + ENABLE_IN_ADDR_TRANS); + wmb(); + + /* + * Program outbound translation windows + * + * Outbound window is what is referred to as "PCI client" region in HRM + * + * Could use the larger alternative address space to get >>64M regions + * for graphics cards etc., but will not bother at this point. + * + * IP bug means that AMBA window size must be a power of 2 + * + * Set mem0 window for first 16MB of outbound window non-prefetchable + * Set mem1 window for second 16MB of outbound window prefetchable + * Set io window for next 16MB of outbound window + * Set cfg0 for final 1MB of outbound window + * + * Ignore mem1, cfg1 and msg windows for now as no obvious use cases for + * 820 that would need them + * + * Probably ideally want no offset between mem0 window start as seen by + * ARM and as seen on PCI bus and get Linux to assign memory regions to + * PCI devices using the same "PCI client" region start address as seen + * by ARM + */ + + /* Set PCIeA mem0 region to be 1st 16MB of the 64MB PCIeA window */ + regmap_write(pcie->sys_ctrl, pcie->outbound_offset + PCIE_IN0_MEM_ADDR, pcie->non_mem.start); + regmap_write(pcie->sys_ctrl, pcie->outbound_offset + PCIE_IN0_MEM_LIMIT, pcie->non_mem.end); + regmap_write(pcie->sys_ctrl, pcie->outbound_offset + PCIE_POM0_MEM_ADDR, pcie->non_mem.start); + + /* Set PCIeA mem1 region to be 2nd 16MB of the 64MB PCIeA window */ + regmap_write(pcie->sys_ctrl, pcie->outbound_offset + PCIE_IN1_MEM_ADDR, pcie->pre_mem.start); + regmap_write(pcie->sys_ctrl, pcie->outbound_offset + PCIE_IN1_MEM_LIMIT, pcie->pre_mem.end); + regmap_write(pcie->sys_ctrl, pcie->outbound_offset + PCIE_POM1_MEM_ADDR, pcie->pre_mem.start); + + /* Set PCIeA io to be third 16M region of the 64MB PCIeA window*/ + regmap_write(pcie->sys_ctrl, pcie->outbound_offset + PCIE_IN_IO_ADDR, pcie->io.start); + regmap_write(pcie->sys_ctrl, pcie->outbound_offset + PCIE_IN_IO_LIMIT, pcie->io.end); + + + /* Set PCIeA cgf0 to be last 16M region of the 64MB PCIeA window*/ + regmap_write(pcie->sys_ctrl, pcie->outbound_offset + PCIE_IN_CFG0_ADDR, pcie->cfg.start); + regmap_write(pcie->sys_ctrl, pcie->outbound_offset + PCIE_IN_CFG0_LIMIT, pcie->cfg.end); + wmb(); + + /* Enable outbound address translation */ + regmap_write_bits(pcie->sys_ctrl, pcie->pcie_ctrl_offset, PCIE_OBTRANS, PCIE_OBTRANS); + wmb(); + + /* + * Program PCIe command register for core to: + * enable memory space + * enable bus master + * enable io + */ + writel_relaxed(7, pcie->base + PCI_CONFIG_COMMAND_STATUS); + /* which is which */ + wmb(); +} + +static unsigned oxnas_pcie_cfg_to_offset( + struct pci_sys_data *sys, + unsigned char bus_number, + unsigned int devfn, + int where) +{ + unsigned int function = PCI_FUNC(devfn); + unsigned int slot = PCI_SLOT(devfn); + unsigned char bus_number_offset; + + bus_number_offset = bus_number - sys->busnr; + + /* + * We'll assume for now that the offset, function, slot, bus encoding + * should map onto linear, contiguous addresses in PCIe config space, + * albeit that the majority will be unused as only slot 0 is valid for + * any PCIe bus and most devices have only function 0 + * + * Could be that PCIe in fact works by not encoding the slot number into + * the config space address as it's known that only slot 0 is valid. + * We'll have to experiment if/when we get a PCIe switch connected to + * the PCIe host + */ + return (bus_number_offset << 20) | (slot << 15) | (function << 12) | + (where & ~3); +} + +/* PCI configuration space write function */ +static int oxnas_pcie_wr_conf(struct pci_bus *bus, u32 devfn, + int where, int size, u32 val) +{ + unsigned long flags; + struct oxnas_pcie *pcie = sys_to_pcie(bus->sysdata); + unsigned offset; + u32 value; + u32 lanes; + + /* Only a single device per bus for PCIe point-to-point links */ + if (PCI_SLOT(devfn) > 0) + return PCIBIOS_DEVICE_NOT_FOUND; + + if (!pcie->haslink) + return PCIBIOS_DEVICE_NOT_FOUND; + + offset = oxnas_pcie_cfg_to_offset(bus->sysdata, bus->number, devfn, + where); + + value = val << (8 * (where & 3)); + lanes = (0xf >> (4-size)) << (where & 3); + /* it race with mem and io write, but the possibility is low, normally + * all config writes happens at driver initialize stage, wont interleave + * with others. + * and many pcie cards use dword (4bytes) access mem/io access only, + * so not bother to copy that ugly work-around now. */ + spin_lock_irqsave(&pcie->lock, flags); + set_out_lanes(pcie, lanes); + writel_relaxed(value, pcie->cfgbase + offset); + set_out_lanes(pcie, 0xf); + spin_unlock_irqrestore(&pcie->lock, flags); + + return PCIBIOS_SUCCESSFUL; +} + +/* PCI configuration space read function */ +static int oxnas_pcie_rd_conf(struct pci_bus *bus, u32 devfn, int where, + int size, u32 *val) +{ + struct oxnas_pcie *pcie = sys_to_pcie(bus->sysdata); + unsigned offset; + u32 value; + u32 left_bytes, right_bytes; + + /* Only a single device per bus for PCIe point-to-point links */ + if (PCI_SLOT(devfn) > 0) { + *val = 0xffffffff; + return PCIBIOS_DEVICE_NOT_FOUND; + } + + if (!pcie->haslink) { + *val = 0xffffffff; + return PCIBIOS_DEVICE_NOT_FOUND; + } + + offset = oxnas_pcie_cfg_to_offset(bus->sysdata, bus->number, devfn, + where); + value = readl_relaxed(pcie->cfgbase + offset); + left_bytes = where & 3; + right_bytes = 4 - left_bytes - size; + value <<= right_bytes * 8; + value >>= (left_bytes + right_bytes) * 8; + *val = value; + + return PCIBIOS_SUCCESSFUL; +} + +static struct pci_ops oxnas_pcie_ops = { + .read = oxnas_pcie_rd_conf, + .write = oxnas_pcie_wr_conf, +}; + +static int oxnas_pcie_setup(int nr, struct pci_sys_data *sys) +{ + struct oxnas_pcie *pcie = sys_to_pcie(sys); + + pci_add_resource_offset(&sys->resources, &pcie->non_mem, sys->mem_offset); + pci_add_resource_offset(&sys->resources, &pcie->pre_mem, sys->mem_offset); + pci_add_resource_offset(&sys->resources, &pcie->io, sys->io_offset); + pci_add_resource(&sys->resources, &pcie->busn); + if (sys->busnr == 0) { /* default one */ + sys->busnr = pcie->busn.start; + } + /* do not use devm_ioremap_resource, it does not like cfg resource */ + pcie->cfgbase = devm_ioremap(&pcie->pdev->dev, pcie->cfg.start, + resource_size(&pcie->cfg)); + if (!pcie->cfgbase) + return -ENOMEM; + + oxnas_pcie_setup_hw(pcie); + + return 1; +} + +static void oxnas_pcie_enable(struct device *dev, struct oxnas_pcie *pcie) +{ + struct hw_pci hw; + int i; + + memset(&hw, 0, sizeof(hw)); + for (i = 0; i < NUM_CONTROLLERS; i++) + pcie->private_data[i] = pcie; + + hw.nr_controllers = NUM_CONTROLLERS; +/* I think use stack pointer is a bad idea though it is valid in this case */ + hw.private_data = pcie->private_data; + hw.setup = oxnas_pcie_setup; + hw.map_irq = of_irq_parse_and_map_pci; + hw.ops = &oxnas_pcie_ops; + + /* pass dev to maintain of tree, interrupt mapping rely on this */ + pci_common_init_dev(dev, &hw); +} + +static int oxnas_pcie_shared_init(struct platform_device *pdev, struct oxnas_pcie *pcie) +{ + if (++pcie_shared.refcount == 1) { + phy_init(pcie->phy); + phy_power_on(pcie->phy); + return 0; + } else { + return 0; + } +} + +#if 0 +/* maybe we will call it when enter low power state */ +static void oxnas_pcie_shared_deinit(struct platform_device *pdev) +{ + if (--pcie_shared.refcount == 0) { + /* no cleanup needed */; + } +} +#endif + +static int +oxnas_pcie_map_registers(struct platform_device *pdev, + struct device_node *np, + struct oxnas_pcie *pcie) +{ + struct resource regs; + int ret = 0; + u32 outbound_ctrl_offset; + u32 pcie_ctrl_offset; + + ret = of_address_to_resource(np, 0, ®s); + if (ret) { + dev_err(&pdev->dev, "failed to parse base register space\n"); + return -EINVAL; + } + + pcie->base = devm_ioremap_resource(&pdev->dev, ®s); + if (!pcie->base) { + dev_err(&pdev->dev, "failed to map base register space\n"); + return -ENOMEM; + } + + ret = of_address_to_resource(np, 1, ®s); + if (ret) { + dev_err(&pdev->dev, "failed to parse inbound register space\n"); + return -EINVAL; + } + + pcie->inbound = devm_ioremap_resource(&pdev->dev, ®s); + if (!pcie->inbound) { + dev_err(&pdev->dev, "failed to map inbound register space\n"); + return -ENOMEM; + } + + pcie->phy = devm_of_phy_get(&pdev->dev, np, NULL); + if (IS_ERR(pcie->phy)) { + if (PTR_ERR(pcie->phy) == -EPROBE_DEFER) { + dev_err(&pdev->dev, "failed to probe phy\n"); + return PTR_ERR(pcie->phy); + } + dev_warn(&pdev->dev, "phy not attached\n"); + pcie->phy = NULL; + } + + if (of_property_read_u32(np, "plxtech,pcie-outbound-offset", + &outbound_ctrl_offset)) { + dev_err(&pdev->dev, "failed to parse outbound register offset\n"); + return -EINVAL; + } + pcie->outbound_offset = outbound_ctrl_offset; + + if (of_property_read_u32(np, "plxtech,pcie-ctrl-offset", + &pcie_ctrl_offset)) { + dev_err(&pdev->dev, "failed to parse pcie-ctrl register offset\n"); + return -EINVAL; + } + pcie->pcie_ctrl_offset = pcie_ctrl_offset; + + return 0; +} + +static int oxnas_pcie_init_res(struct platform_device *pdev, + struct oxnas_pcie *pcie, + struct device_node *np) +{ + struct of_pci_range range; + struct of_pci_range_parser parser; + int ret; + + if (of_pci_range_parser_init(&parser, np)) + return -EINVAL; + + /* Get the I/O and memory ranges from DT */ + for_each_of_pci_range(&parser, &range) { + + unsigned long restype = range.flags & IORESOURCE_TYPE_BITS; + if (restype == IORESOURCE_IO) { + of_pci_range_to_resource(&range, np, &pcie->io); + pcie->io.name = "I/O"; + } + if (restype == IORESOURCE_MEM) { + if (range.flags & IORESOURCE_PREFETCH) { + of_pci_range_to_resource(&range, np, &pcie->pre_mem); + pcie->pre_mem.name = "PRE MEM"; + } else { + of_pci_range_to_resource(&range, np, &pcie->non_mem); + pcie->non_mem.name = "NON MEM"; + } + + } + if (restype == 0) + of_pci_range_to_resource(&range, np, &pcie->cfg); + } + + /* Get the bus range */ + ret = of_pci_parse_bus_range(np, &pcie->busn); + + if (ret) { + dev_err(&pdev->dev, "failed to parse bus-range property: %d\n", + ret); + return ret; + } + + pcie->card_reset = of_get_gpio(np, 0); + if (pcie->card_reset < 0) + dev_info(&pdev->dev, "card reset gpio pin not exists\n"); + + if (of_property_read_u32(np, "plxtech,pcie-hcsl-bit", &pcie->hcsl_en)) + return -EINVAL; + + pcie->clk = of_clk_get_by_name(np, "pcie"); + if (IS_ERR(pcie->clk)) { + return PTR_ERR(pcie->clk); + } + + pcie->busclk = of_clk_get_by_name(np, "busclk"); + if (IS_ERR(pcie->busclk)) { + clk_put(pcie->clk); + return PTR_ERR(pcie->busclk); + } + + return 0; +} + +static void oxnas_pcie_init_hw(struct platform_device *pdev, + struct oxnas_pcie *pcie) +{ + u32 version_id; + int ret; + + clk_prepare_enable(pcie->busclk); + + /* reset PCIe cards use hard-wired gpio pin */ + if (pcie->card_reset >= 0 && + !gpio_direction_output(pcie->card_reset, 0)) { + wmb(); + mdelay(10); + /* must tri-state the pin to pull it up */ + gpio_direction_input(pcie->card_reset); + wmb(); + mdelay(100); + } + + /* ToDo: use phy power-on port... */ + regmap_update_bits(pcie->sys_ctrl, SYS_CTRL_HCSL_CTRL_REGOFFSET, + BIT(pcie->hcsl_en), BIT(pcie->hcsl_en)); + + /* core */ + ret = device_reset(&pdev->dev); + if (ret) { + dev_err(&pdev->dev, "core reset failed %d\n", ret); + return; + } + + /* Start PCIe core clocks */ + clk_prepare_enable(pcie->clk); + + version_id = readl_relaxed(pcie->base + PCI_CONFIG_VERSION_DEVICEID); + dev_info(&pdev->dev, "PCIe version/deviceID 0x%x\n", version_id); + + if (version_id != VERSION_ID_MAGIC) { + dev_info(&pdev->dev, "PCIe controller not found\n"); + pcie->haslink = 0; + return; + } + + /* allow entry to L23 state */ + regmap_write_bits(pcie->sys_ctrl, pcie->pcie_ctrl_offset, + PCIE_READY_ENTR_L23, PCIE_READY_ENTR_L23); + + /* Set PCIe core into RootCore mode */ + regmap_write_bits(pcie->sys_ctrl, pcie->pcie_ctrl_offset, + PCIE_DEVICE_TYPE_MASK, PCIE_DEVICE_TYPE_ROOT); + wmb(); + + /* Bring up the PCI core */ + regmap_write_bits(pcie->sys_ctrl, pcie->pcie_ctrl_offset, + PCIE_LTSSM, PCIE_LTSSM); + wmb(); +} + +static int oxnas_pcie_probe(struct platform_device *pdev) +{ + struct oxnas_pcie *pcie; + struct device_node *np = pdev->dev.of_node; + int ret; + + pcie = devm_kzalloc(&pdev->dev, sizeof(struct oxnas_pcie), + GFP_KERNEL); + if (!pcie) + return -ENOMEM; + + pcie->pdev = pdev; + pcie->haslink = 1; + spin_lock_init(&pcie->lock); + + pcie->sys_ctrl = syscon_regmap_lookup_by_compatible("oxsemi,ox820-sys-ctrl"); + if (IS_ERR(pcie->sys_ctrl)) + return PTR_ERR(pcie->sys_ctrl); + + ret = oxnas_pcie_init_res(pdev, pcie, np); + if (ret) + return ret; + if (pcie->card_reset >= 0) { + ret = gpio_request_one(pcie->card_reset, GPIOF_DIR_IN, + dev_name(&pdev->dev)); + if (ret) { + dev_err(&pdev->dev, "cannot request gpio pin %d\n", + pcie->card_reset); + return ret; + } + } + + ret = oxnas_pcie_map_registers(pdev, np, pcie); + if (ret) { + dev_err(&pdev->dev, "cannot map registers\n"); + goto err_free_gpio; + } + + ret = oxnas_pcie_shared_init(pdev, pcie); + if (ret) + goto err_free_gpio; + + /* if hw not found, haslink cleared */ + oxnas_pcie_init_hw(pdev, pcie); + + if (pcie->haslink && oxnas_pcie_link_up(pcie)) { + pcie->haslink = 1; + dev_info(&pdev->dev, "link up\n"); + } else { + pcie->haslink = 0; + dev_info(&pdev->dev, "link down\n"); + } + /* should we register our controller even when pcie->haslink is 0 ? */ + /* register the controller with framework */ + oxnas_pcie_enable(&pdev->dev, pcie); + + return 0; + +err_free_gpio: + if (pcie->card_reset) + gpio_free(pcie->card_reset); + + return ret; +} + +static const struct of_device_id oxnas_pcie_of_match_table[] = { + { .compatible = "plxtech,nas782x-pcie", }, + {}, +}; + +static struct platform_driver oxnas_pcie_driver = { + .driver = { + .name = "oxnas-pcie", + .suppress_bind_attrs = true, + .of_match_table = oxnas_pcie_of_match_table, + }, + .probe = oxnas_pcie_probe, +}; + +builtin_platform_driver(oxnas_pcie_driver); |