pcie-artpec6.c
// SPDX-License-Identifier: GPL-2.0
/*
* PCIe host controller driver for Axis ARTPEC-6 SoC
*
* Author: Niklas Cassel <niklas.cassel@axis.com>
*
* Based on work done by Phil Edworthy <phil@edworthys.org>
*/
#include <linux/delay.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/of_device.h>
#include <linux/pci.h>
#include <linux/platform_device.h>
#include <linux/resource.h>
#include <linux/signal.h>
#include <linux/types.h>
#include <linux/interrupt.h>
#include <linux/mfd/syscon.h>
#include <linux/regmap.h>
#include "pcie-designware.h"
#define to_artpec6_pcie(x) dev_get_drvdata((x)->dev)
enum artpec_pcie_variants {
ARTPEC6,
ARTPEC7,
};
struct artpec6_pcie {
struct dw_pcie *pci;
struct regmap *regmap; /* DT axis,syscon-pcie */
void __iomem *phy_base; /* DT phy */
enum artpec_pcie_variants variant;
enum dw_pcie_device_mode mode;
};
struct artpec_pcie_of_data {
enum artpec_pcie_variants variant;
enum dw_pcie_device_mode mode;
};
static const struct of_device_id artpec6_pcie_of_match[];
/* PCIe Port Logic registers (memory-mapped) */
#define PL_OFFSET 0x700
#define ACK_F_ASPM_CTRL_OFF (PL_OFFSET + 0xc)
#define ACK_N_FTS_MASK GENMASK(15, 8)
#define ACK_N_FTS(x) (((x) << 8) & ACK_N_FTS_MASK)
#define FAST_TRAINING_SEQ_MASK GENMASK(7, 0)
#define FAST_TRAINING_SEQ(x) (((x) << 0) & FAST_TRAINING_SEQ_MASK)
/* ARTPEC-6 specific registers */
#define PCIECFG 0x18
#define PCIECFG_DBG_OEN BIT(24)
#define PCIECFG_CORE_RESET_REQ BIT(21)
#define PCIECFG_LTSSM_ENABLE BIT(20)
#define PCIECFG_DEVICE_TYPE_MASK GENMASK(19, 16)
#define PCIECFG_CLKREQ_B BIT(11)
#define PCIECFG_REFCLK_ENABLE BIT(10)
#define PCIECFG_PLL_ENABLE BIT(9)
#define PCIECFG_PCLK_ENABLE BIT(8)
#define PCIECFG_RISRCREN BIT(4)
#define PCIECFG_MODE_TX_DRV_EN BIT(3)
#define PCIECFG_CISRREN BIT(2)
#define PCIECFG_MACRO_ENABLE BIT(0)
/* ARTPEC-7 specific fields */
#define PCIECFG_REFCLKSEL BIT(23)
#define PCIECFG_NOC_RESET BIT(3)
#define PCIESTAT 0x1c
/* ARTPEC-7 specific fields */
#define PCIESTAT_EXTREFCLK BIT(3)
#define NOCCFG 0x40
#define NOCCFG_ENABLE_CLK_PCIE BIT(4)
#define NOCCFG_POWER_PCIE_IDLEACK BIT(3)
#define NOCCFG_POWER_PCIE_IDLE BIT(2)
#define NOCCFG_POWER_PCIE_IDLEREQ BIT(1)
#define PHY_STATUS 0x118
#define PHY_COSPLLLOCK BIT(0)
#define PHY_TX_ASIC_OUT 0x4040
#define PHY_TX_ASIC_OUT_TX_ACK BIT(0)
#define PHY_RX_ASIC_OUT 0x405c
#define PHY_RX_ASIC_OUT_ACK BIT(0)
static u32 artpec6_pcie_readl(struct artpec6_pcie *artpec6_pcie, u32 offset)
{
u32 val;
regmap_read(artpec6_pcie->regmap, offset, &val);
return val;
}
static void artpec6_pcie_writel(struct artpec6_pcie *artpec6_pcie, u32 offset, u32 val)
{
regmap_write(artpec6_pcie->regmap, offset, val);
}
static u64 artpec6_pcie_cpu_addr_fixup(struct dw_pcie *pci, u64 pci_addr)
{
struct artpec6_pcie *artpec6_pcie = to_artpec6_pcie(pci);
struct pcie_port *pp = &pci->pp;
struct dw_pcie_ep *ep = &pci->ep;
switch (artpec6_pcie->mode) {
case DW_PCIE_RC_TYPE:
return pci_addr - pp->cfg0_base;
case DW_PCIE_EP_TYPE:
return pci_addr - ep->phys_base;
default:
dev_err(pci->dev, "UNKNOWN device type\n");
}
return pci_addr;
}
static int artpec6_pcie_establish_link(struct dw_pcie *pci)
{
struct artpec6_pcie *artpec6_pcie = to_artpec6_pcie(pci);
u32 val;
val = artpec6_pcie_readl(artpec6_pcie, PCIECFG);
val |= PCIECFG_LTSSM_ENABLE;
artpec6_pcie_writel(artpec6_pcie, PCIECFG, val);
return 0;
}
static void artpec6_pcie_stop_link(struct dw_pcie *pci)
{
struct artpec6_pcie *artpec6_pcie = to_artpec6_pcie(pci);
u32 val;
val = artpec6_pcie_readl(artpec6_pcie, PCIECFG);
val &= ~PCIECFG_LTSSM_ENABLE;
artpec6_pcie_writel(artpec6_pcie, PCIECFG, val);
}
static const struct dw_pcie_ops dw_pcie_ops = {
.cpu_addr_fixup = artpec6_pcie_cpu_addr_fixup,
.start_link = artpec6_pcie_establish_link,
.stop_link = artpec6_pcie_stop_link,
};
static void artpec6_pcie_wait_for_phy_a6(struct artpec6_pcie *artpec6_pcie)
{
struct dw_pcie *pci = artpec6_pcie->pci;
struct device *dev = pci->dev;
u32 val;
unsigned int retries;
retries = 50;
do {
usleep_range(1000, 2000);
val = artpec6_pcie_readl(artpec6_pcie, NOCCFG);
retries--;
} while (retries &&
(val & (NOCCFG_POWER_PCIE_IDLEACK | NOCCFG_POWER_PCIE_IDLE)));
if (!retries)
dev_err(dev, "PCIe clock manager did not leave idle state\n");
retries = 50;
do {
usleep_range(1000, 2000);
val = readl(artpec6_pcie->phy_base + PHY_STATUS);
retries--;
} while (retries && !(val & PHY_COSPLLLOCK));
if (!retries)
dev_err(dev, "PHY PLL did not lock\n");
}
static void artpec6_pcie_wait_for_phy_a7(struct artpec6_pcie *artpec6_pcie)
{
struct dw_pcie *pci = artpec6_pcie->pci;
struct device *dev = pci->dev;
u32 val;
u16 phy_status_tx, phy_status_rx;
unsigned int retries;
retries = 50;
do {
usleep_range(1000, 2000);
val = artpec6_pcie_readl(artpec6_pcie, NOCCFG);
retries--;
} while (retries &&
(val & (NOCCFG_POWER_PCIE_IDLEACK | NOCCFG_POWER_PCIE_IDLE)));
if (!retries)
dev_err(dev, "PCIe clock manager did not leave idle state\n");
retries = 50;
do {
usleep_range(1000, 2000);
phy_status_tx = readw(artpec6_pcie->phy_base + PHY_TX_ASIC_OUT);
phy_status_rx = readw(artpec6_pcie->phy_base + PHY_RX_ASIC_OUT);
retries--;
} while (retries && ((phy_status_tx & PHY_TX_ASIC_OUT_TX_ACK) ||
(phy_status_rx & PHY_RX_ASIC_OUT_ACK)));
if (!retries)
dev_err(dev, "PHY did not enter Pn state\n");
}
static void artpec6_pcie_wait_for_phy(struct artpec6_pcie *artpec6_pcie)
{
switch (artpec6_pcie->variant) {
case ARTPEC6:
artpec6_pcie_wait_for_phy_a6(artpec6_pcie);
break;
case ARTPEC7:
artpec6_pcie_wait_for_phy_a7(artpec6_pcie);
break;
}
}
static void artpec6_pcie_init_phy_a6(struct artpec6_pcie *artpec6_pcie)
{
u32 val;
val = artpec6_pcie_readl(artpec6_pcie, PCIECFG);
val |= PCIECFG_RISRCREN | /* Receiver term. 50 Ohm */
PCIECFG_MODE_TX_DRV_EN |
PCIECFG_CISRREN | /* Reference clock term. 100 Ohm */
PCIECFG_MACRO_ENABLE;
val |= PCIECFG_REFCLK_ENABLE;
val &= ~PCIECFG_DBG_OEN;
val &= ~PCIECFG_CLKREQ_B;
artpec6_pcie_writel(artpec6_pcie, PCIECFG, val);
usleep_range(5000, 6000);
val = artpec6_pcie_readl(artpec6_pcie, NOCCFG);
val |= NOCCFG_ENABLE_CLK_PCIE;
artpec6_pcie_writel(artpec6_pcie, NOCCFG, val);
usleep_range(20, 30);
val = artpec6_pcie_readl(artpec6_pcie, PCIECFG);
val |= PCIECFG_PCLK_ENABLE | PCIECFG_PLL_ENABLE;
artpec6_pcie_writel(artpec6_pcie, PCIECFG, val);
usleep_range(6000, 7000);
val = artpec6_pcie_readl(artpec6_pcie, NOCCFG);
val &= ~NOCCFG_POWER_PCIE_IDLEREQ;
artpec6_pcie_writel(artpec6_pcie, NOCCFG, val);
}
static void artpec6_pcie_init_phy_a7(struct artpec6_pcie *artpec6_pcie)
{
struct dw_pcie *pci = artpec6_pcie->pci;
u32 val;
bool extrefclk;
/* Check if external reference clock is connected */
val = artpec6_pcie_readl(artpec6_pcie, PCIESTAT);
extrefclk = !!(val & PCIESTAT_EXTREFCLK);
dev_dbg(pci->dev, "Using reference clock: %s\n",
extrefclk ? "external" : "internal");
val = artpec6_pcie_readl(artpec6_pcie, PCIECFG);
val |= PCIECFG_RISRCREN | /* Receiver term. 50 Ohm */
PCIECFG_PCLK_ENABLE;
if (extrefclk)
val |= PCIECFG_REFCLKSEL;
else
val &= ~PCIECFG_REFCLKSEL;
artpec6_pcie_writel(artpec6_pcie, PCIECFG, val);
usleep_range(10, 20);
val = artpec6_pcie_readl(artpec6_pcie, NOCCFG);
val |= NOCCFG_ENABLE_CLK_PCIE;
artpec6_pcie_writel(artpec6_pcie, NOCCFG, val);
usleep_range(20, 30);
val = artpec6_pcie_readl(artpec6_pcie, NOCCFG);
val &= ~NOCCFG_POWER_PCIE_IDLEREQ;
artpec6_pcie_writel(artpec6_pcie, NOCCFG, val);
}
static void artpec6_pcie_init_phy(struct artpec6_pcie *artpec6_pcie)
{
switch (artpec6_pcie->variant) {
case ARTPEC6:
artpec6_pcie_init_phy_a6(artpec6_pcie);
break;
case ARTPEC7:
artpec6_pcie_init_phy_a7(artpec6_pcie);
break;
}
}
static void artpec6_pcie_set_nfts(struct artpec6_pcie *artpec6_pcie)
{
struct dw_pcie *pci = artpec6_pcie->pci;
u32 val;
if (artpec6_pcie->variant != ARTPEC7)
return;
/*
* Increase the N_FTS (Number of Fast Training Sequences)
* to be transmitted when transitioning from L0s to L0.
*/
val = dw_pcie_readl_dbi(pci, ACK_F_ASPM_CTRL_OFF);
val &= ~ACK_N_FTS_MASK;
val |= ACK_N_FTS(180);
dw_pcie_writel_dbi(pci, ACK_F_ASPM_CTRL_OFF, val);
/*
* Set the Number of Fast Training Sequences that the core
* advertises as its N_FTS during Gen2 or Gen3 link training.
*/
val = dw_pcie_readl_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL);
val &= ~FAST_TRAINING_SEQ_MASK;
val |= FAST_TRAINING_SEQ(180);
dw_pcie_writel_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL, val);
}
static void artpec6_pcie_assert_core_reset(struct artpec6_pcie *artpec6_pcie)
{
u32 val;
val = artpec6_pcie_readl(artpec6_pcie, PCIECFG);
switch (artpec6_pcie->variant) {
case ARTPEC6:
val |= PCIECFG_CORE_RESET_REQ;
break;
case ARTPEC7:
val &= ~PCIECFG_NOC_RESET;
break;
}
artpec6_pcie_writel(artpec6_pcie, PCIECFG, val);
}
static void artpec6_pcie_deassert_core_reset(struct artpec6_pcie *artpec6_pcie)
{
u32 val;
val = artpec6_pcie_readl(artpec6_pcie, PCIECFG);
switch (artpec6_pcie->variant) {
case ARTPEC6:
val &= ~PCIECFG_CORE_RESET_REQ;
break;
case ARTPEC7:
val |= PCIECFG_NOC_RESET;
break;
}
artpec6_pcie_writel(artpec6_pcie, PCIECFG, val);
usleep_range(100, 200);
}
static void artpec6_pcie_enable_interrupts(struct artpec6_pcie *artpec6_pcie)
{
struct dw_pcie *pci = artpec6_pcie->pci;
struct pcie_port *pp = &pci->pp;
if (IS_ENABLED(CONFIG_PCI_MSI))
dw_pcie_msi_init(pp);
}
static int artpec6_pcie_host_init(struct pcie_port *pp)
{
struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
struct artpec6_pcie *artpec6_pcie = to_artpec6_pcie(pci);
artpec6_pcie_assert_core_reset(artpec6_pcie);
artpec6_pcie_init_phy(artpec6_pcie);
artpec6_pcie_deassert_core_reset(artpec6_pcie);
artpec6_pcie_wait_for_phy(artpec6_pcie);
artpec6_pcie_set_nfts(artpec6_pcie);
dw_pcie_setup_rc(pp);
artpec6_pcie_establish_link(pci);
dw_pcie_wait_for_link(pci);
artpec6_pcie_enable_interrupts(artpec6_pcie);
return 0;
}
static const struct dw_pcie_host_ops artpec6_pcie_host_ops = {
.host_init = artpec6_pcie_host_init,
};
static int artpec6_add_pcie_port(struct artpec6_pcie *artpec6_pcie,
struct platform_device *pdev)
{
struct dw_pcie *pci = artpec6_pcie->pci;
struct pcie_port *pp = &pci->pp;
struct device *dev = pci->dev;
int ret;
if (IS_ENABLED(CONFIG_PCI_MSI)) {
pp->msi_irq = platform_get_irq_byname(pdev, "msi");
if (pp->msi_irq < 0) {
dev_err(dev, "failed to get MSI irq\n");
return pp->msi_irq;
}
}
pp->root_bus_nr = -1;
pp->ops = &artpec6_pcie_host_ops;
ret = dw_pcie_host_init(pp);
if (ret) {
dev_err(dev, "failed to initialize host\n");
return ret;
}
return 0;
}
static void artpec6_pcie_ep_init(struct dw_pcie_ep *ep)
{
struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
struct artpec6_pcie *artpec6_pcie = to_artpec6_pcie(pci);
enum pci_barno bar;
artpec6_pcie_assert_core_reset(artpec6_pcie);
artpec6_pcie_init_phy(artpec6_pcie);
artpec6_pcie_deassert_core_reset(artpec6_pcie);
artpec6_pcie_wait_for_phy(artpec6_pcie);
artpec6_pcie_set_nfts(artpec6_pcie);
for (bar = BAR_0; bar <= BAR_5; bar++)
dw_pcie_ep_reset_bar(pci, bar);
}
static int artpec6_pcie_raise_irq(struct dw_pcie_ep *ep, u8 func_no,
enum pci_epc_irq_type type, u8 interrupt_num)
{
struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
switch (type) {
case PCI_EPC_IRQ_LEGACY:
dev_err(pci->dev, "EP cannot trigger legacy IRQs\n");
return -EINVAL;
case PCI_EPC_IRQ_MSI:
return dw_pcie_ep_raise_msi_irq(ep, func_no, interrupt_num);
default:
dev_err(pci->dev, "UNKNOWN IRQ type\n");
}
return 0;
}
static struct dw_pcie_ep_ops pcie_ep_ops = {
.ep_init = artpec6_pcie_ep_init,
.raise_irq = artpec6_pcie_raise_irq,
};
static int artpec6_add_pcie_ep(struct artpec6_pcie *artpec6_pcie,
struct platform_device *pdev)
{
int ret;
struct dw_pcie_ep *ep;
struct resource *res;
struct device *dev = &pdev->dev;
struct dw_pcie *pci = artpec6_pcie->pci;
ep = &pci->ep;
ep->ops = &pcie_ep_ops;
res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dbi2");
pci->dbi_base2 = devm_ioremap(dev, res->start, resource_size(res));
if (!pci->dbi_base2)
return -ENOMEM;
res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "addr_space");
if (!res)
return -EINVAL;
ep->phys_base = res->start;
ep->addr_size = resource_size(res);
ret = dw_pcie_ep_init(ep);
if (ret) {
dev_err(dev, "failed to initialize endpoint\n");
return ret;
}
return 0;
}
static int artpec6_pcie_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct dw_pcie *pci;
struct artpec6_pcie *artpec6_pcie;
struct resource *dbi_base;
struct resource *phy_base;
int ret;
const struct of_device_id *match;
const struct artpec_pcie_of_data *data;
enum artpec_pcie_variants variant;
enum dw_pcie_device_mode mode;
match = of_match_device(artpec6_pcie_of_match, dev);
if (!match)
return -EINVAL;
data = (struct artpec_pcie_of_data *)match->data;
variant = (enum artpec_pcie_variants)data->variant;
mode = (enum dw_pcie_device_mode)data->mode;
artpec6_pcie = devm_kzalloc(dev, sizeof(*artpec6_pcie), GFP_KERNEL);
if (!artpec6_pcie)
return -ENOMEM;
pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL);
if (!pci)
return -ENOMEM;
pci->dev = dev;
pci->ops = &dw_pcie_ops;
artpec6_pcie->pci = pci;
artpec6_pcie->variant = variant;
artpec6_pcie->mode = mode;
dbi_base = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dbi");
pci->dbi_base = devm_ioremap_resource(dev, dbi_base);
if (IS_ERR(pci->dbi_base))
return PTR_ERR(pci->dbi_base);
phy_base = platform_get_resource_byname(pdev, IORESOURCE_MEM, "phy");
artpec6_pcie->phy_base = devm_ioremap_resource(dev, phy_base);
if (IS_ERR(artpec6_pcie->phy_base))
return PTR_ERR(artpec6_pcie->phy_base);
artpec6_pcie->regmap =
syscon_regmap_lookup_by_phandle(dev->of_node,
"axis,syscon-pcie");
if (IS_ERR(artpec6_pcie->regmap))
return PTR_ERR(artpec6_pcie->regmap);
platform_set_drvdata(pdev, artpec6_pcie);
switch (artpec6_pcie->mode) {
case DW_PCIE_RC_TYPE:
if (!IS_ENABLED(CONFIG_PCIE_ARTPEC6_HOST))
return -ENODEV;
ret = artpec6_add_pcie_port(artpec6_pcie, pdev);
if (ret < 0)
return ret;
break;
case DW_PCIE_EP_TYPE: {
u32 val;
if (!IS_ENABLED(CONFIG_PCIE_ARTPEC6_EP))
return -ENODEV;
val = artpec6_pcie_readl(artpec6_pcie, PCIECFG);
val &= ~PCIECFG_DEVICE_TYPE_MASK;
artpec6_pcie_writel(artpec6_pcie, PCIECFG, val);
ret = artpec6_add_pcie_ep(artpec6_pcie, pdev);
if (ret < 0)
return ret;
break;
}
default:
dev_err(dev, "INVALID device type %d\n", artpec6_pcie->mode);
}
return 0;
}
static const struct artpec_pcie_of_data artpec6_pcie_rc_of_data = {
.variant = ARTPEC6,
.mode = DW_PCIE_RC_TYPE,
};
static const struct artpec_pcie_of_data artpec6_pcie_ep_of_data = {
.variant = ARTPEC6,
.mode = DW_PCIE_EP_TYPE,
};
static const struct artpec_pcie_of_data artpec7_pcie_rc_of_data = {
.variant = ARTPEC7,
.mode = DW_PCIE_RC_TYPE,
};
static const struct artpec_pcie_of_data artpec7_pcie_ep_of_data = {
.variant = ARTPEC7,
.mode = DW_PCIE_EP_TYPE,
};
static const struct of_device_id artpec6_pcie_of_match[] = {
{
.compatible = "axis,artpec6-pcie",
.data = &artpec6_pcie_rc_of_data,
},
{
.compatible = "axis,artpec6-pcie-ep",
.data = &artpec6_pcie_ep_of_data,
},
{
.compatible = "axis,artpec7-pcie",
.data = &artpec7_pcie_rc_of_data,
},
{
.compatible = "axis,artpec7-pcie-ep",
.data = &artpec7_pcie_ep_of_data,
},
{},
};
static struct platform_driver artpec6_pcie_driver = {
.probe = artpec6_pcie_probe,
.driver = {
.name = "artpec6-pcie",
.of_match_table = artpec6_pcie_of_match,
.suppress_bind_attrs = true,
},
};
builtin_platform_driver(artpec6_pcie_driver);