linux/drivers/pci/controller/mobiveil/pcie-layerscape-gen4.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * PCIe Gen4 host controller driver for NXP Layerscape SoCs
   4 *
   5 * Copyright 2019-2020 NXP
   6 *
   7 * Author: Zhiqiang Hou <Zhiqiang.Hou@nxp.com>
   8 */
   9
  10#include <linux/kernel.h>
  11#include <linux/interrupt.h>
  12#include <linux/init.h>
  13#include <linux/of_pci.h>
  14#include <linux/of_platform.h>
  15#include <linux/of_irq.h>
  16#include <linux/of_address.h>
  17#include <linux/pci.h>
  18#include <linux/platform_device.h>
  19#include <linux/resource.h>
  20#include <linux/mfd/syscon.h>
  21#include <linux/regmap.h>
  22
  23#include "pcie-mobiveil.h"
  24
  25/* LUT and PF control registers */
  26#define PCIE_LUT_OFF                    0x80000
  27#define PCIE_PF_OFF                     0xc0000
  28#define PCIE_PF_INT_STAT                0x18
  29#define PF_INT_STAT_PABRST              BIT(31)
  30
  31#define PCIE_PF_DBG                     0x7fc
  32#define PF_DBG_LTSSM_MASK               0x3f
  33#define PF_DBG_LTSSM_L0                 0x2d /* L0 state */
  34#define PF_DBG_WE                       BIT(31)
  35#define PF_DBG_PABR                     BIT(27)
  36
  37#define to_ls_pcie_g4(x)                platform_get_drvdata((x)->pdev)
  38
  39struct ls_pcie_g4 {
  40        struct mobiveil_pcie pci;
  41        struct delayed_work dwork;
  42        int irq;
  43};
  44
  45static inline u32 ls_pcie_g4_pf_readl(struct ls_pcie_g4 *pcie, u32 off)
  46{
  47        return ioread32(pcie->pci.csr_axi_slave_base + PCIE_PF_OFF + off);
  48}
  49
  50static inline void ls_pcie_g4_pf_writel(struct ls_pcie_g4 *pcie,
  51                                        u32 off, u32 val)
  52{
  53        iowrite32(val, pcie->pci.csr_axi_slave_base + PCIE_PF_OFF + off);
  54}
  55
  56static int ls_pcie_g4_link_up(struct mobiveil_pcie *pci)
  57{
  58        struct ls_pcie_g4 *pcie = to_ls_pcie_g4(pci);
  59        u32 state;
  60
  61        state = ls_pcie_g4_pf_readl(pcie, PCIE_PF_DBG);
  62        state = state & PF_DBG_LTSSM_MASK;
  63
  64        if (state == PF_DBG_LTSSM_L0)
  65                return 1;
  66
  67        return 0;
  68}
  69
  70static void ls_pcie_g4_disable_interrupt(struct ls_pcie_g4 *pcie)
  71{
  72        struct mobiveil_pcie *mv_pci = &pcie->pci;
  73
  74        mobiveil_csr_writel(mv_pci, 0, PAB_INTP_AMBA_MISC_ENB);
  75}
  76
  77static void ls_pcie_g4_enable_interrupt(struct ls_pcie_g4 *pcie)
  78{
  79        struct mobiveil_pcie *mv_pci = &pcie->pci;
  80        u32 val;
  81
  82        /* Clear the interrupt status */
  83        mobiveil_csr_writel(mv_pci, 0xffffffff, PAB_INTP_AMBA_MISC_STAT);
  84
  85        val = PAB_INTP_INTX_MASK | PAB_INTP_MSI | PAB_INTP_RESET |
  86              PAB_INTP_PCIE_UE | PAB_INTP_IE_PMREDI | PAB_INTP_IE_EC;
  87        mobiveil_csr_writel(mv_pci, val, PAB_INTP_AMBA_MISC_ENB);
  88}
  89
  90static int ls_pcie_g4_reinit_hw(struct ls_pcie_g4 *pcie)
  91{
  92        struct mobiveil_pcie *mv_pci = &pcie->pci;
  93        struct device *dev = &mv_pci->pdev->dev;
  94        u32 val, act_stat;
  95        int to = 100;
  96
  97        /* Poll for pab_csb_reset to set and PAB activity to clear */
  98        do {
  99                usleep_range(10, 15);
 100                val = ls_pcie_g4_pf_readl(pcie, PCIE_PF_INT_STAT);
 101                act_stat = mobiveil_csr_readl(mv_pci, PAB_ACTIVITY_STAT);
 102        } while (((val & PF_INT_STAT_PABRST) == 0 || act_stat) && to--);
 103        if (to < 0) {
 104                dev_err(dev, "Poll PABRST&PABACT timeout\n");
 105                return -EIO;
 106        }
 107
 108        /* clear PEX_RESET bit in PEX_PF0_DBG register */
 109        val = ls_pcie_g4_pf_readl(pcie, PCIE_PF_DBG);
 110        val |= PF_DBG_WE;
 111        ls_pcie_g4_pf_writel(pcie, PCIE_PF_DBG, val);
 112
 113        val = ls_pcie_g4_pf_readl(pcie, PCIE_PF_DBG);
 114        val |= PF_DBG_PABR;
 115        ls_pcie_g4_pf_writel(pcie, PCIE_PF_DBG, val);
 116
 117        val = ls_pcie_g4_pf_readl(pcie, PCIE_PF_DBG);
 118        val &= ~PF_DBG_WE;
 119        ls_pcie_g4_pf_writel(pcie, PCIE_PF_DBG, val);
 120
 121        mobiveil_host_init(mv_pci, true);
 122
 123        to = 100;
 124        while (!ls_pcie_g4_link_up(mv_pci) && to--)
 125                usleep_range(200, 250);
 126        if (to < 0) {
 127                dev_err(dev, "PCIe link training timeout\n");
 128                return -EIO;
 129        }
 130
 131        return 0;
 132}
 133
 134static irqreturn_t ls_pcie_g4_isr(int irq, void *dev_id)
 135{
 136        struct ls_pcie_g4 *pcie = (struct ls_pcie_g4 *)dev_id;
 137        struct mobiveil_pcie *mv_pci = &pcie->pci;
 138        u32 val;
 139
 140        val = mobiveil_csr_readl(mv_pci, PAB_INTP_AMBA_MISC_STAT);
 141        if (!val)
 142                return IRQ_NONE;
 143
 144        if (val & PAB_INTP_RESET) {
 145                ls_pcie_g4_disable_interrupt(pcie);
 146                schedule_delayed_work(&pcie->dwork, msecs_to_jiffies(1));
 147        }
 148
 149        mobiveil_csr_writel(mv_pci, val, PAB_INTP_AMBA_MISC_STAT);
 150
 151        return IRQ_HANDLED;
 152}
 153
 154static int ls_pcie_g4_interrupt_init(struct mobiveil_pcie *mv_pci)
 155{
 156        struct ls_pcie_g4 *pcie = to_ls_pcie_g4(mv_pci);
 157        struct platform_device *pdev = mv_pci->pdev;
 158        struct device *dev = &pdev->dev;
 159        int ret;
 160
 161        pcie->irq = platform_get_irq_byname(pdev, "intr");
 162        if (pcie->irq < 0)
 163                return pcie->irq;
 164
 165        ret = devm_request_irq(dev, pcie->irq, ls_pcie_g4_isr,
 166                               IRQF_SHARED, pdev->name, pcie);
 167        if (ret) {
 168                dev_err(dev, "Can't register PCIe IRQ, errno = %d\n", ret);
 169                return  ret;
 170        }
 171
 172        return 0;
 173}
 174
 175static void ls_pcie_g4_reset(struct work_struct *work)
 176{
 177        struct delayed_work *dwork = container_of(work, struct delayed_work,
 178                                                  work);
 179        struct ls_pcie_g4 *pcie = container_of(dwork, struct ls_pcie_g4, dwork);
 180        struct mobiveil_pcie *mv_pci = &pcie->pci;
 181        u16 ctrl;
 182
 183        ctrl = mobiveil_csr_readw(mv_pci, PCI_BRIDGE_CONTROL);
 184        ctrl &= ~PCI_BRIDGE_CTL_BUS_RESET;
 185        mobiveil_csr_writew(mv_pci, ctrl, PCI_BRIDGE_CONTROL);
 186
 187        if (!ls_pcie_g4_reinit_hw(pcie))
 188                return;
 189
 190        ls_pcie_g4_enable_interrupt(pcie);
 191}
 192
 193static struct mobiveil_rp_ops ls_pcie_g4_rp_ops = {
 194        .interrupt_init = ls_pcie_g4_interrupt_init,
 195};
 196
 197static const struct mobiveil_pab_ops ls_pcie_g4_pab_ops = {
 198        .link_up = ls_pcie_g4_link_up,
 199};
 200
 201static int __init ls_pcie_g4_probe(struct platform_device *pdev)
 202{
 203        struct device *dev = &pdev->dev;
 204        struct pci_host_bridge *bridge;
 205        struct mobiveil_pcie *mv_pci;
 206        struct ls_pcie_g4 *pcie;
 207        struct device_node *np = dev->of_node;
 208        int ret;
 209
 210        if (!of_parse_phandle(np, "msi-parent", 0)) {
 211                dev_err(dev, "Failed to find msi-parent\n");
 212                return -EINVAL;
 213        }
 214
 215        bridge = devm_pci_alloc_host_bridge(dev, sizeof(*pcie));
 216        if (!bridge)
 217                return -ENOMEM;
 218
 219        pcie = pci_host_bridge_priv(bridge);
 220        mv_pci = &pcie->pci;
 221
 222        mv_pci->pdev = pdev;
 223        mv_pci->ops = &ls_pcie_g4_pab_ops;
 224        mv_pci->rp.ops = &ls_pcie_g4_rp_ops;
 225        mv_pci->rp.bridge = bridge;
 226
 227        platform_set_drvdata(pdev, pcie);
 228
 229        INIT_DELAYED_WORK(&pcie->dwork, ls_pcie_g4_reset);
 230
 231        ret = mobiveil_pcie_host_probe(mv_pci);
 232        if (ret) {
 233                dev_err(dev, "Fail to probe\n");
 234                return  ret;
 235        }
 236
 237        ls_pcie_g4_enable_interrupt(pcie);
 238
 239        return 0;
 240}
 241
 242static const struct of_device_id ls_pcie_g4_of_match[] = {
 243        { .compatible = "fsl,lx2160a-pcie", },
 244        { },
 245};
 246
 247static struct platform_driver ls_pcie_g4_driver = {
 248        .driver = {
 249                .name = "layerscape-pcie-gen4",
 250                .of_match_table = ls_pcie_g4_of_match,
 251                .suppress_bind_attrs = true,
 252        },
 253};
 254
 255builtin_platform_driver_probe(ls_pcie_g4_driver, ls_pcie_g4_probe);
 256