// SPDX-License-Identifier: GPL-2.0
/*
* PCIe Gen4 host controller driver for NXP Layerscape SoCs
*
* Copyright 2019-2020 NXP
*
* Author: Zhiqiang Hou <[email protected]>
*/
#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 const 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);
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