diff options
Diffstat (limited to 'drivers/pci/controller/mobiveil/pcie-layerscape-gen4.c')
-rw-r--r-- | drivers/pci/controller/mobiveil/pcie-layerscape-gen4.c | 255 |
1 files changed, 255 insertions, 0 deletions
diff --git a/drivers/pci/controller/mobiveil/pcie-layerscape-gen4.c b/drivers/pci/controller/mobiveil/pcie-layerscape-gen4.c new file mode 100644 index 0000000000..d7b7350f02 --- /dev/null +++ b/drivers/pci/controller/mobiveil/pcie-layerscape-gen4.c @@ -0,0 +1,255 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * PCIe Gen4 host controller driver for NXP Layerscape SoCs + * + * Copyright 2019-2020 NXP + * + * Author: Zhiqiang Hou <Zhiqiang.Hou@nxp.com> + */ + +#include <linux/kernel.h> +#include <linux/interrupt.h> +#include <linux/init.h> +#include <linux/of_pci.h> +#include <linux/of_platform.h> +#include <linux/of_irq.h> +#include <linux/of_address.h> +#include <linux/pci.h> +#include <linux/platform_device.h> +#include <linux/resource.h> +#include <linux/mfd/syscon.h> +#include <linux/regmap.h> + +#include "pcie-mobiveil.h" + +/* LUT and PF control registers */ +#define PCIE_LUT_OFF 0x80000 +#define PCIE_PF_OFF 0xc0000 +#define PCIE_PF_INT_STAT 0x18 +#define PF_INT_STAT_PABRST BIT(31) + +#define PCIE_PF_DBG 0x7fc +#define PF_DBG_LTSSM_MASK 0x3f +#define PF_DBG_LTSSM_L0 0x2d /* L0 state */ +#define PF_DBG_WE BIT(31) +#define PF_DBG_PABR BIT(27) + +#define to_ls_g4_pcie(x) platform_get_drvdata((x)->pdev) + +struct ls_g4_pcie { + struct mobiveil_pcie pci; + struct delayed_work dwork; + int irq; +}; + +static inline u32 ls_g4_pcie_pf_readl(struct ls_g4_pcie *pcie, u32 off) +{ + return ioread32(pcie->pci.csr_axi_slave_base + PCIE_PF_OFF + off); +} + +static inline void ls_g4_pcie_pf_writel(struct ls_g4_pcie *pcie, + u32 off, u32 val) +{ + iowrite32(val, pcie->pci.csr_axi_slave_base + PCIE_PF_OFF + off); +} + +static int ls_g4_pcie_link_up(struct mobiveil_pcie *pci) +{ + struct ls_g4_pcie *pcie = to_ls_g4_pcie(pci); + u32 state; + + state = ls_g4_pcie_pf_readl(pcie, PCIE_PF_DBG); + state = state & PF_DBG_LTSSM_MASK; + + if (state == PF_DBG_LTSSM_L0) + return 1; + + return 0; +} + +static void ls_g4_pcie_disable_interrupt(struct ls_g4_pcie *pcie) +{ + struct mobiveil_pcie *mv_pci = &pcie->pci; + + mobiveil_csr_writel(mv_pci, 0, PAB_INTP_AMBA_MISC_ENB); +} + +static void ls_g4_pcie_enable_interrupt(struct ls_g4_pcie *pcie) +{ + struct mobiveil_pcie *mv_pci = &pcie->pci; + u32 val; + + /* Clear the interrupt status */ + mobiveil_csr_writel(mv_pci, 0xffffffff, PAB_INTP_AMBA_MISC_STAT); + + val = PAB_INTP_INTX_MASK | PAB_INTP_MSI | PAB_INTP_RESET | + PAB_INTP_PCIE_UE | PAB_INTP_IE_PMREDI | PAB_INTP_IE_EC; + mobiveil_csr_writel(mv_pci, val, PAB_INTP_AMBA_MISC_ENB); +} + +static int ls_g4_pcie_reinit_hw(struct ls_g4_pcie *pcie) +{ + struct mobiveil_pcie *mv_pci = &pcie->pci; + struct device *dev = &mv_pci->pdev->dev; + u32 val, act_stat; + int to = 100; + + /* Poll for pab_csb_reset to set and PAB activity to clear */ + do { + usleep_range(10, 15); + val = ls_g4_pcie_pf_readl(pcie, PCIE_PF_INT_STAT); + act_stat = mobiveil_csr_readl(mv_pci, PAB_ACTIVITY_STAT); + } while (((val & PF_INT_STAT_PABRST) == 0 || act_stat) && to--); + if (to < 0) { + dev_err(dev, "Poll PABRST&PABACT timeout\n"); + return -EIO; + } + + /* clear PEX_RESET bit in PEX_PF0_DBG register */ + val = ls_g4_pcie_pf_readl(pcie, PCIE_PF_DBG); + val |= PF_DBG_WE; + ls_g4_pcie_pf_writel(pcie, PCIE_PF_DBG, val); + + val = ls_g4_pcie_pf_readl(pcie, PCIE_PF_DBG); + val |= PF_DBG_PABR; + ls_g4_pcie_pf_writel(pcie, PCIE_PF_DBG, val); + + val = ls_g4_pcie_pf_readl(pcie, PCIE_PF_DBG); + val &= ~PF_DBG_WE; + ls_g4_pcie_pf_writel(pcie, PCIE_PF_DBG, val); + + mobiveil_host_init(mv_pci, true); + + to = 100; + while (!ls_g4_pcie_link_up(mv_pci) && to--) + usleep_range(200, 250); + if (to < 0) { + dev_err(dev, "PCIe link training timeout\n"); + return -EIO; + } + + return 0; +} + +static irqreturn_t ls_g4_pcie_isr(int irq, void *dev_id) +{ + struct ls_g4_pcie *pcie = (struct ls_g4_pcie *)dev_id; + struct mobiveil_pcie *mv_pci = &pcie->pci; + u32 val; + + val = mobiveil_csr_readl(mv_pci, PAB_INTP_AMBA_MISC_STAT); + if (!val) + return IRQ_NONE; + + if (val & PAB_INTP_RESET) { + ls_g4_pcie_disable_interrupt(pcie); + schedule_delayed_work(&pcie->dwork, msecs_to_jiffies(1)); + } + + mobiveil_csr_writel(mv_pci, val, PAB_INTP_AMBA_MISC_STAT); + + return IRQ_HANDLED; +} + +static int ls_g4_pcie_interrupt_init(struct mobiveil_pcie *mv_pci) +{ + struct ls_g4_pcie *pcie = to_ls_g4_pcie(mv_pci); + struct platform_device *pdev = mv_pci->pdev; + struct device *dev = &pdev->dev; + int ret; + + pcie->irq = platform_get_irq_byname(pdev, "intr"); + if (pcie->irq < 0) + return pcie->irq; + + ret = devm_request_irq(dev, pcie->irq, ls_g4_pcie_isr, + IRQF_SHARED, pdev->name, pcie); + if (ret) { + dev_err(dev, "Can't register PCIe IRQ, errno = %d\n", ret); + return ret; + } + + return 0; +} + +static void ls_g4_pcie_reset(struct work_struct *work) +{ + struct delayed_work *dwork = container_of(work, struct delayed_work, + work); + struct ls_g4_pcie *pcie = container_of(dwork, struct ls_g4_pcie, dwork); + struct mobiveil_pcie *mv_pci = &pcie->pci; + u16 ctrl; + + ctrl = mobiveil_csr_readw(mv_pci, PCI_BRIDGE_CONTROL); + ctrl &= ~PCI_BRIDGE_CTL_BUS_RESET; + mobiveil_csr_writew(mv_pci, ctrl, PCI_BRIDGE_CONTROL); + + if (!ls_g4_pcie_reinit_hw(pcie)) + return; + + ls_g4_pcie_enable_interrupt(pcie); +} + +static struct mobiveil_rp_ops ls_g4_pcie_rp_ops = { + .interrupt_init = ls_g4_pcie_interrupt_init, +}; + +static const struct mobiveil_pab_ops ls_g4_pcie_pab_ops = { + .link_up = ls_g4_pcie_link_up, +}; + +static int __init ls_g4_pcie_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct pci_host_bridge *bridge; + struct mobiveil_pcie *mv_pci; + struct ls_g4_pcie *pcie; + struct device_node *np = dev->of_node; + int ret; + + if (!of_parse_phandle(np, "msi-parent", 0)) { + dev_err(dev, "Failed to find msi-parent\n"); + return -EINVAL; + } + + bridge = devm_pci_alloc_host_bridge(dev, sizeof(*pcie)); + if (!bridge) + return -ENOMEM; + + pcie = pci_host_bridge_priv(bridge); + mv_pci = &pcie->pci; + + mv_pci->pdev = pdev; + mv_pci->ops = &ls_g4_pcie_pab_ops; + mv_pci->rp.ops = &ls_g4_pcie_rp_ops; + mv_pci->rp.bridge = bridge; + + platform_set_drvdata(pdev, pcie); + + INIT_DELAYED_WORK(&pcie->dwork, ls_g4_pcie_reset); + + ret = mobiveil_pcie_host_probe(mv_pci); + if (ret) { + dev_err(dev, "Fail to probe\n"); + return ret; + } + + ls_g4_pcie_enable_interrupt(pcie); + + return 0; +} + +static const struct of_device_id ls_g4_pcie_of_match[] = { + { .compatible = "fsl,lx2160a-pcie", }, + { }, +}; + +static struct platform_driver ls_g4_pcie_driver = { + .driver = { + .name = "layerscape-pcie-gen4", + .of_match_table = ls_g4_pcie_of_match, + .suppress_bind_attrs = true, + }, +}; + +builtin_platform_driver_probe(ls_g4_pcie_driver, ls_g4_pcie_probe); |