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author | Álvaro Fernández Rojas <noltari@gmail.com> | 2021-03-23 20:12:22 +0100 |
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committer | Álvaro Fernández Rojas <noltari@gmail.com> | 2021-03-23 20:12:22 +0100 |
commit | 7f04d675170d255580edf77d4ff7c0adebb57609 (patch) | |
tree | 4cc1d76bc8d8497ef63c1a7b6ce68bd0d32eac9e /target/linux/bmips/files/drivers/pci/controller/pcie-bcm6328.c | |
parent | 851dadc257b7223f879a3733507e83cfcaae1af1 (diff) | |
download | upstream-7f04d675170d255580edf77d4ff7c0adebb57609.tar.gz upstream-7f04d675170d255580edf77d4ff7c0adebb57609.tar.bz2 upstream-7f04d675170d255580edf77d4ff7c0adebb57609.zip |
bmips: add experimental PCI/PCIe support
These PCI drivers are a bit hacky and definitely not suitable for upstreaming,
but hopefully we can use them as a base for developing proper upstream PCI
drivers.
Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
Diffstat (limited to 'target/linux/bmips/files/drivers/pci/controller/pcie-bcm6328.c')
-rw-r--r-- | target/linux/bmips/files/drivers/pci/controller/pcie-bcm6328.c | 412 |
1 files changed, 412 insertions, 0 deletions
diff --git a/target/linux/bmips/files/drivers/pci/controller/pcie-bcm6328.c b/target/linux/bmips/files/drivers/pci/controller/pcie-bcm6328.c new file mode 100644 index 0000000000..4c0d3723b8 --- /dev/null +++ b/target/linux/bmips/files/drivers/pci/controller/pcie-bcm6328.c @@ -0,0 +1,412 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * BCM6328 PCIe Controller Driver + * + * Copyright (C) 2020 Álvaro Fernández Rojas <noltari@gmail.com> + * Copyright (C) 2015 Jonas Gorski <jonas.gorski@gmail.com> + * Copyright (C) 2008 Maxime Bizon <mbizon@freebox.fr> + */ + +#include <linux/clk.h> +#include <linux/init.h> +#include <linux/delay.h> +#include <linux/kernel.h> +#include <linux/mfd/syscon.h> +#include <linux/mm.h> +#include <linux/of_gpio.h> +#include <linux/of_irq.h> +#include <linux/of_pci.h> +#include <linux/of_platform.h> +#include <linux/pci.h> +#include <linux/pm_domain.h> +#include <linux/pm_runtime.h> +#include <linux/reset.h> +#include <linux/regmap.h> +#include <linux/types.h> +#include <linux/vmalloc.h> + +#include "../pci.h" + +#define SERDES_PCIE_EXD_EN BIT(15) +#define SERDES_PCIE_EN BIT(0) + +#define PCIE_BUS_BRIDGE 0 +#define PCIE_BUS_DEVICE 1 + +#define PCIE_CONFIG2_REG 0x408 +#define CONFIG2_BAR1_SIZE_EN 1 +#define CONFIG2_BAR1_SIZE_MASK 0xf + +#define PCIE_IDVAL3_REG 0x43c +#define IDVAL3_CLASS_CODE_MASK 0xffffff +#define IDVAL3_SUBCLASS_SHIFT 8 +#define IDVAL3_CLASS_SHIFT 16 + +#define PCIE_DLSTATUS_REG 0x1048 +#define DLSTATUS_PHYLINKUP (1 << 13) + +#define PCIE_BRIDGE_OPT1_REG 0x2820 +#define OPT1_RD_BE_OPT_EN (1 << 7) +#define OPT1_RD_REPLY_BE_FIX_EN (1 << 9) +#define OPT1_PCIE_BRIDGE_HOLE_DET_EN (1 << 11) +#define OPT1_L1_INT_STATUS_MASK_POL (1 << 12) + +#define PCIE_BRIDGE_OPT2_REG 0x2824 +#define OPT2_UBUS_UR_DECODE_DIS (1 << 2) +#define OPT2_TX_CREDIT_CHK_EN (1 << 4) +#define OPT2_CFG_TYPE1_BD_SEL (1 << 7) +#define OPT2_CFG_TYPE1_BUS_NO_SHIFT 16 +#define OPT2_CFG_TYPE1_BUS_NO_MASK (0xff << OPT2_CFG_TYPE1_BUS_NO_SHIFT) + +#define PCIE_BRIDGE_BAR0_BASEMASK_REG 0x2828 +#define BASEMASK_REMAP_EN (1 << 0) +#define BASEMASK_SWAP_EN (1 << 1) +#define BASEMASK_MASK_SHIFT 4 +#define BASEMASK_MASK_MASK (0xfff << BASEMASK_MASK_SHIFT) +#define BASEMASK_BASE_SHIFT 20 +#define BASEMASK_BASE_MASK (0xfff << BASEMASK_BASE_SHIFT) + +#define PCIE_BRIDGE_BAR0_REBASE_ADDR_REG 0x282c +#define REBASE_ADDR_BASE_SHIFT 20 +#define REBASE_ADDR_BASE_MASK (0xfff << REBASE_ADDR_BASE_SHIFT) + +#define PCIE_BRIDGE_RC_INT_MASK_REG 0x2854 +#define PCIE_RC_INT_A (1 << 0) +#define PCIE_RC_INT_B (1 << 1) +#define PCIE_RC_INT_C (1 << 2) +#define PCIE_RC_INT_D (1 << 3) + +#define PCIE_DEVICE_OFFSET 0x8000 + +struct bcm6328_pcie { + void __iomem *base; + int irq; + struct regmap *serdes; + struct device **pm; + struct device_link **link_pm; + unsigned int num_pms; + struct clk *clk; + struct reset_control *reset; + struct reset_control *reset_ext; + struct reset_control *reset_core; + struct reset_control *reset_hard; +}; + +static struct bcm6328_pcie bcm6328_pcie; + +extern int bmips_pci_irq; + +/* + * swizzle 32bits data to return only the needed part + */ +static int postprocess_read(u32 data, int where, unsigned int size) +{ + u32 ret = 0; + + switch (size) { + case 1: + ret = (data >> ((where & 3) << 3)) & 0xff; + break; + case 2: + ret = (data >> ((where & 3) << 3)) & 0xffff; + break; + case 4: + ret = data; + break; + } + + return ret; +} + +static int preprocess_write(u32 orig_data, u32 val, int where, + unsigned int size) +{ + u32 ret = 0; + + switch (size) { + case 1: + ret = (orig_data & ~(0xff << ((where & 3) << 3))) | + (val << ((where & 3) << 3)); + break; + case 2: + ret = (orig_data & ~(0xffff << ((where & 3) << 3))) | + (val << ((where & 3) << 3)); + break; + case 4: + ret = val; + break; + } + + return ret; +} + +static int bcm6328_pcie_can_access(struct pci_bus *bus, int devfn) +{ + struct bcm6328_pcie *priv = &bcm6328_pcie; + + switch (bus->number) { + case PCIE_BUS_BRIDGE: + return PCI_SLOT(devfn) == 0; + case PCIE_BUS_DEVICE: + if (PCI_SLOT(devfn) == 0) + return __raw_readl(priv->base + PCIE_DLSTATUS_REG) + & DLSTATUS_PHYLINKUP; + /* else, fall through */ + default: + return false; + } +} + +static int bcm6328_pcie_read(struct pci_bus *bus, unsigned int devfn, + int where, int size, u32 *val) +{ + struct bcm6328_pcie *priv = &bcm6328_pcie; + u32 data; + u32 reg = where & ~3; + + if (!bcm6328_pcie_can_access(bus, devfn)) + return PCIBIOS_DEVICE_NOT_FOUND; + + if (bus->number == PCIE_BUS_DEVICE) + reg += PCIE_DEVICE_OFFSET; + + data = __raw_readl(priv->base + reg); + *val = postprocess_read(data, where, size); + + return PCIBIOS_SUCCESSFUL; +} + +static int bcm6328_pcie_write(struct pci_bus *bus, unsigned int devfn, + int where, int size, u32 val) +{ + struct bcm6328_pcie *priv = &bcm6328_pcie; + u32 data; + u32 reg = where & ~3; + + if (!bcm6328_pcie_can_access(bus, devfn)) + return PCIBIOS_DEVICE_NOT_FOUND; + + if (bus->number == PCIE_BUS_DEVICE) + reg += PCIE_DEVICE_OFFSET; + + data = __raw_readl(priv->base + reg); + data = preprocess_write(data, val, where, size); + __raw_writel(data, priv->base + reg); + + return PCIBIOS_SUCCESSFUL; +} + +static struct pci_ops bcm6328_pcie_ops = { + .read = bcm6328_pcie_read, + .write = bcm6328_pcie_write, +}; + +static struct resource bcm6328_pcie_io_resource; +static struct resource bcm6328_pcie_mem_resource; +static struct resource bcm6328_pcie_busn_resource; + +static struct pci_controller bcm6328_pcie_controller = { + .pci_ops = &bcm6328_pcie_ops, + .io_resource = &bcm6328_pcie_io_resource, + .mem_resource = &bcm6328_pcie_mem_resource, + .busn_resource = &bcm6328_pcie_busn_resource, +}; + +static void bcm6328_pcie_reset(struct bcm6328_pcie *priv) +{ + regmap_write_bits(priv->serdes, 0, + SERDES_PCIE_EXD_EN | SERDES_PCIE_EN, + SERDES_PCIE_EXD_EN | SERDES_PCIE_EN); + + reset_control_assert(priv->reset); + reset_control_assert(priv->reset_core); + reset_control_assert(priv->reset_ext); + if (priv->reset_hard) { + reset_control_assert(priv->reset_hard); + mdelay(10); + reset_control_deassert(priv->reset_hard); + } + mdelay(10); + + reset_control_deassert(priv->reset_core); + reset_control_deassert(priv->reset); + mdelay(10); + + reset_control_deassert(priv->reset_ext); + mdelay(200); +} + +static void bcm6328_pcie_setup(struct bcm6328_pcie *priv) +{ + u32 val; + + val = __raw_readl(priv->base + PCIE_BRIDGE_OPT1_REG); + val |= OPT1_RD_BE_OPT_EN; + val |= OPT1_RD_REPLY_BE_FIX_EN; + val |= OPT1_PCIE_BRIDGE_HOLE_DET_EN; + val |= OPT1_L1_INT_STATUS_MASK_POL; + __raw_writel(val, priv->base + PCIE_BRIDGE_OPT1_REG); + + val = __raw_readl(priv->base + PCIE_BRIDGE_RC_INT_MASK_REG); + val |= PCIE_RC_INT_A; + val |= PCIE_RC_INT_B; + val |= PCIE_RC_INT_C; + val |= PCIE_RC_INT_D; + __raw_writel(val, priv->base + PCIE_BRIDGE_RC_INT_MASK_REG); + + val = __raw_readl(priv->base + PCIE_BRIDGE_OPT2_REG); + /* enable credit checking and error checking */ + val |= OPT2_TX_CREDIT_CHK_EN; + val |= OPT2_UBUS_UR_DECODE_DIS; + /* set device bus/func for the pcie device */ + val |= (PCIE_BUS_DEVICE << OPT2_CFG_TYPE1_BUS_NO_SHIFT); + val |= OPT2_CFG_TYPE1_BD_SEL; + __raw_writel(val, priv->base + PCIE_BRIDGE_OPT2_REG); + + /* setup class code as bridge */ + val = __raw_readl(priv->base + PCIE_IDVAL3_REG); + val &= ~IDVAL3_CLASS_CODE_MASK; + val |= (PCI_CLASS_BRIDGE_PCI << IDVAL3_SUBCLASS_SHIFT); + __raw_writel(val, priv->base + PCIE_IDVAL3_REG); + + /* disable bar1 size */ + val = __raw_readl(priv->base + PCIE_CONFIG2_REG); + val &= ~CONFIG2_BAR1_SIZE_MASK; + __raw_writel(val, priv->base + PCIE_CONFIG2_REG); + + /* set bar0 to little endian */ + val = (bcm6328_pcie_mem_resource.start >> 20) + << BASEMASK_BASE_SHIFT; + val |= (bcm6328_pcie_mem_resource.end >> 20) << BASEMASK_MASK_SHIFT; + val |= BASEMASK_REMAP_EN; + __raw_writel(val, priv->base + PCIE_BRIDGE_BAR0_BASEMASK_REG); + + val = (bcm6328_pcie_mem_resource.start >> 20) + << REBASE_ADDR_BASE_SHIFT; + __raw_writel(val, priv->base + PCIE_BRIDGE_BAR0_REBASE_ADDR_REG); +} + +static int bcm6328_pcie_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct device_node *np = dev->of_node; + struct bcm6328_pcie *priv = &bcm6328_pcie; + struct resource *res; + unsigned int i; + int ret; + + pm_runtime_enable(dev); + pm_runtime_no_callbacks(dev); + + priv->num_pms = of_count_phandle_with_args(np, "power-domains", + "#power-domain-cells"); + if (priv->num_pms > 1) { + priv->pm = devm_kcalloc(dev, priv->num_pms, + sizeof(struct device *), GFP_KERNEL); + if (!priv->pm) + return -ENOMEM; + + priv->link_pm = devm_kcalloc(dev, priv->num_pms, + sizeof(struct device_link *), + GFP_KERNEL); + if (!priv->link_pm) + return -ENOMEM; + + for (i = 0; i < priv->num_pms; i++) { + priv->pm[i] = genpd_dev_pm_attach_by_id(dev, i); + if (IS_ERR(priv->pm[i])) { + dev_err(dev, "error getting pm %d\n", i); + return -EINVAL; + } + + priv->link_pm[i] = device_link_add(dev, priv->pm[i], + DL_FLAG_STATELESS | DL_FLAG_PM_RUNTIME | + DL_FLAG_RPM_ACTIVE); + } + } + + ret = pm_runtime_get_sync(dev); + if (ret < 0) { + pm_runtime_disable(dev); + dev_info(dev, "PM prober defer: ret=%d\n", ret); + return -EPROBE_DEFER; + } + + of_pci_check_probe_only(); + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + priv->base = devm_ioremap_resource(dev, res); + if (IS_ERR(priv->base)) + return PTR_ERR(priv->base); + + priv->irq = platform_get_irq(pdev, 0); + if (!priv->irq) + return -ENODEV; + + bmips_pci_irq = priv->irq; + + priv->serdes = syscon_regmap_lookup_by_phandle(np, "brcm,serdes"); + if (IS_ERR(priv->serdes)) + return PTR_ERR(priv->serdes); + + priv->reset = devm_reset_control_get(dev, "pcie"); + if (IS_ERR(priv->reset)) + return PTR_ERR(priv->reset); + + priv->reset_ext = devm_reset_control_get(dev, "pcie-ext"); + if (IS_ERR(priv->reset_ext)) + return PTR_ERR(priv->reset_ext); + + priv->reset_core = devm_reset_control_get(dev, "pcie-core"); + if (IS_ERR(priv->reset_core)) + return PTR_ERR(priv->reset_core); + + priv->reset_hard = devm_reset_control_get_optional(dev, "pcie-hard"); + if (IS_ERR(priv->reset_hard)) + return PTR_ERR(priv->reset_hard); + + priv->clk = devm_clk_get(dev, "pcie"); + if (IS_ERR(priv->clk)) + return PTR_ERR(priv->clk); + + ret = clk_prepare_enable(priv->clk); + if (ret) { + dev_err(dev, "could not enable clock\n"); + return ret; + } + + pci_load_of_ranges(&bcm6328_pcie_controller, np); + if (!bcm6328_pcie_mem_resource.start) + return -EINVAL; + + of_pci_parse_bus_range(np, &bcm6328_pcie_busn_resource); + + bcm6328_pcie_reset(priv); + bcm6328_pcie_setup(priv); + + register_pci_controller(&bcm6328_pcie_controller); + + return 0; +} + +static const struct of_device_id bcm6328_pcie_of_match[] = { + { .compatible = "brcm,bcm6328-pcie", }, + { /* sentinel */ } +}; + +static struct platform_driver bcm6328_pcie_driver = { + .probe = bcm6328_pcie_probe, + .driver = { + .name = "bcm6328-pcie", + .of_match_table = bcm6328_pcie_of_match, + }, +}; + +int __init bcm6328_pcie_init(void) +{ + int ret = platform_driver_register(&bcm6328_pcie_driver); + if (ret) + pr_err("pci-bcm6328: Error registering platform driver!\n"); + return ret; +} +late_initcall_sync(bcm6328_pcie_init); |