Re: [PATCH 5/5] PCI: cadence: add EndPoint Controller driver for Cadence PCIe controller

Lorenzo Pieralisi
2017-12-01T12:20:20Z

On Thu, Nov 23, 2017 at 04:01:50PM +0100, Cyrille Pitchen wrote:
> This patch adds support to the Cadence PCIe controller in endpoint mode.

Please add a brief description to the log to describe the most salient
features.

> Signed-off-by: Cyrille Pitchen <cyrille.pitchen@free-electrons.com>
> ---
> drivers/pci/cadence/Kconfig | 9 +
> drivers/pci/cadence/Makefile | 1 +
> drivers/pci/cadence/pcie-cadence-ep.c | 553 ++++++++++++++++++++++++++++++++++
> 3 files changed, 563 insertions(+)
> create mode 100644 drivers/pci/cadence/pcie-cadence-ep.c
>
> diff --git a/drivers/pci/cadence/Kconfig b/drivers/pci/cadence/Kconfig
> index 120306cae2aa..b2e6af71f39e 100644
> --- a/drivers/pci/cadence/Kconfig
> +++ b/drivers/pci/cadence/Kconfig
> @@ -21,4 +21,13 @@ config PCIE_CADENCE_HOST
> mode. This PCIe controller may be embedded into many different vendors
> SoCs.
>
> +config PCIE_CADENCE_EP
> + bool "Cadence PCIe endpoint controller"
> + depends on PCI_ENDPOINT
> + select PCIE_CADENCE
> + help
> + Say Y here if you want to support the Cadence PCIe controller in
> + endpoint mode. This PCIe controller may be embedded into many
> + different vendors SoCs.
> +
> endif # PCI_CADENCE
> diff --git a/drivers/pci/cadence/Makefile b/drivers/pci/cadence/Makefile
> index d57d192d2595..61e9c8d6839d 100644
> --- a/drivers/pci/cadence/Makefile
> +++ b/drivers/pci/cadence/Makefile
> @@ -1,2 +1,3 @@
> obj-$(CONFIG_PCIE_CADENCE) += pcie-cadence.o
> obj-$(CONFIG_PCIE_CADENCE_HOST) += pcie-cadence-host.o
> +obj-$(CONFIG_PCIE_CADENCE_EP) += pcie-cadence-ep.o
> diff --git a/drivers/pci/cadence/pcie-cadence-ep.c b/drivers/pci/cadence/pcie-cadence-ep.c
> new file mode 100644
> index 000000000000..a1d761101a9c
> --- /dev/null
> +++ b/drivers/pci/cadence/pcie-cadence-ep.c
> @@ -0,0 +1,553 @@
> +/*
> + * Cadence PCIe host controller driver.

You should update this comment.

> + *
> + * Copyright (c) 2017 Cadence
> + *
> + * Author: Cyrille Pitchen <cyrille.pitchen@free-electrons.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License along with
> + * this program. If not, see <http://www.gnu.org/licenses/>.
> + */
> +#include <linux/kernel.h>
> +#include <linux/of.h>
> +#include <linux/pci-epc.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/sizes.h>
> +#include <linux/delay.h>

Nit: alphabetical order.

> +#include "pcie-cadence.h"
> +
> +#define CDNS_PCIE_EP_MIN_APERTURE 128 /* 128 bytes */
> +#define CDNS_PCIE_EP_IRQ_PCI_ADDR_NONE 0x1
> +#define CDNS_PCIE_EP_IRQ_PCI_ADDR_LEGACY 0x3
> +
> +/**
> + * struct cdns_pcie_ep_data - hardware specific data
> + * @max_regions: maximum nmuber of regions supported by hardware

s/nmuber/number

> + */
> +struct cdns_pcie_ep_data {
> + size_t max_regions;
> +};
> +
> +/**
> + * struct cdns_pcie_ep - private data for this PCIe endpoint controller driver
> + * @pcie: Cadence PCIe controller
> + * @data: pointer to a 'struct cdns_pcie_data'
> + */
> +struct cdns_pcie_ep {
> + struct cdns_pcie pcie;
> + const struct cdns_pcie_ep_data *data;
> + struct pci_epc *epc;
> + unsigned long ob_region_map;
> + phys_addr_t *ob_addr;
> + phys_addr_t irq_phys_addr;
> + void __iomem *irq_cpu_addr;
> + u64 irq_pci_addr;
> + u8 irq_pending;
> +};
> +
> +static int cdns_pcie_ep_write_header(struct pci_epc *epc,
> + struct pci_epf_header *hdr)
> +{
> + struct cdns_pcie_ep *ep = epc_get_drvdata(epc);
> + struct cdns_pcie *pcie = &ep->pcie;
> + u8 fn = 0;
> +
> + if (fn == 0) {

I think there is some code to retrieve fn missing here.

> + u32 id = CDNS_PCIE_LM_ID_VENDOR(hdr->vendorid) |
> + CDNS_PCIE_LM_ID_SUBSYS(hdr->subsys_vendor_id);
> + cdns_pcie_writel(pcie, CDNS_PCIE_LM_ID, id);
> + }
> + cdns_pcie_ep_fn_writew(pcie, fn, PCI_DEVICE_ID, hdr->deviceid);
> + cdns_pcie_ep_fn_writeb(pcie, fn, PCI_REVISION_ID, hdr->revid);
> + cdns_pcie_ep_fn_writeb(pcie, fn, PCI_CLASS_PROG, hdr->progif_code);
> + cdns_pcie_ep_fn_writew(pcie, fn, PCI_CLASS_DEVICE,
> + hdr->subclass_code | hdr->baseclass_code << 8);
> + cdns_pcie_ep_fn_writeb(pcie, fn, PCI_CACHE_LINE_SIZE,
> + hdr->cache_line_size);
> + cdns_pcie_ep_fn_writew(pcie, fn, PCI_SUBSYSTEM_ID, hdr->subsys_id);
> + cdns_pcie_ep_fn_writeb(pcie, fn, PCI_INTERRUPT_PIN, hdr->interrupt_pin);
> +
> + return 0;
> +}
> +
> +static int cdns_pcie_ep_set_bar(struct pci_epc *epc, enum pci_barno bar,
> + dma_addr_t bar_phys, size_t size, int flags)
> +{
> + struct cdns_pcie_ep *ep = epc_get_drvdata(epc);
> + struct cdns_pcie *pcie = &ep->pcie;
> + u32 addr0, addr1, reg, cfg, b, aperture, ctrl;
> + u8 fn = 0;
> + u64 sz;
> +
> + /* BAR size is 2^(aperture + 7) */
> + sz = max_t(size_t, size, CDNS_PCIE_EP_MIN_APERTURE);
> + sz = 1ULL << fls64(sz - 1);
> + aperture = ilog2(sz) - 7; /* 128B -> 0, 256B -> 1, 512B -> 2, ... */
> +
> + if ((flags & PCI_BASE_ADDRESS_SPACE) == PCI_BASE_ADDRESS_SPACE_IO) {
> + ctrl = CDNS_PCIE_LM_BAR_CFG_CTRL_IO_32BITS;
> + } else {
> + bool is_prefetch = !!(flags & PCI_BASE_ADDRESS_MEM_PREFETCH);
> + bool is_64bits = sz > SZ_2G;
> +
> + if (is_64bits && (bar & 1))
> + return -EINVAL;
> +
> + switch (is_64bits << 1 | is_prefetch) {

I would not mind implementing this as a nested if-else, I am not a big
fan of using bool this way.

> + case 0:
> + ctrl = CDNS_PCIE_LM_BAR_CFG_CTRL_MEM_32BITS;
> + break;
> +
> + case 1:
> + ctrl = CDNS_PCIE_LM_BAR_CFG_CTRL_PREFETCH_MEM_32BITS;
> + break;
> +
> + case 2:
> + ctrl = CDNS_PCIE_LM_BAR_CFG_CTRL_MEM_64BITS;
> + break;
> +
> + case 3:
> + ctrl = CDNS_PCIE_LM_BAR_CFG_CTRL_PREFETCH_MEM_64BITS;
> + break;
> + }
> + }
> +
> + addr0 = lower_32_bits(bar_phys);
> + addr1 = upper_32_bits(bar_phys);
> + cdns_pcie_writel(pcie, CDNS_PCIE_AT_IB_EP_FUNC_BAR_ADDR0(fn, bar),
> + addr0);
> + cdns_pcie_writel(pcie, CDNS_PCIE_AT_IB_EP_FUNC_BAR_ADDR1(fn, bar),
> + addr1);

Is fn always 0 ?

> + if (bar < BAR_4) {
> + reg = CDNS_PCIE_LM_EP_FUNC_BAR_CFG0(fn);
> + b = bar;
> + } else {
> + reg = CDNS_PCIE_LM_EP_FUNC_BAR_CFG1(fn);
> + b = bar - BAR_4;
> + }
> +
> + cfg = cdns_pcie_readl(pcie, reg);
> + cfg &= ~(CDNS_PCIE_LM_EP_FUNC_BAR_CFG_BAR_APERTURE_MASK(b) |
> + CDNS_PCIE_LM_EP_FUNC_BAR_CFG_BAR_CTRL_MASK(b));
> + cfg |= (CDNS_PCIE_LM_EP_FUNC_BAR_CFG_BAR_APERTURE(b, aperture) |
> + CDNS_PCIE_LM_EP_FUNC_BAR_CFG_BAR_CTRL(b, ctrl));
> + cdns_pcie_writel(pcie, reg, cfg);
> +
> + return 0;
> +}
> +
> +static void cdns_pcie_ep_clear_bar(struct pci_epc *epc, enum pci_barno bar)
> +{
> + struct cdns_pcie_ep *ep = epc_get_drvdata(epc);
> + struct cdns_pcie *pcie = &ep->pcie;
> + u32 reg, cfg, b, ctrl;
> + u8 fn = 0;
> +
> + if (bar < BAR_4) {
> + reg = CDNS_PCIE_LM_EP_FUNC_BAR_CFG0(fn);
> + b = bar;
> + } else {
> + reg = CDNS_PCIE_LM_EP_FUNC_BAR_CFG1(fn);
> + b = bar - BAR_4;
> + }
> +
> + ctrl = CDNS_PCIE_LM_BAR_CFG_CTRL_DISABLED;
> + cfg = cdns_pcie_readl(pcie, reg);
> + cfg &= ~(CDNS_PCIE_LM_EP_FUNC_BAR_CFG_BAR_APERTURE_MASK(b) |
> + CDNS_PCIE_LM_EP_FUNC_BAR_CFG_BAR_CTRL_MASK(b));
> + cfg |= CDNS_PCIE_LM_EP_FUNC_BAR_CFG_BAR_CTRL_MASK(ctrl);
> + cdns_pcie_writel(pcie, reg, cfg);
> +
> + cdns_pcie_writel(pcie, CDNS_PCIE_AT_IB_EP_FUNC_BAR_ADDR0(fn, bar), 0);
> + cdns_pcie_writel(pcie, CDNS_PCIE_AT_IB_EP_FUNC_BAR_ADDR1(fn, bar), 0);
> +}
> +
> +static int cdns_pcie_ep_map_addr(struct pci_epc *epc, phys_addr_t addr,
> + u64 pci_addr, size_t size)
> +{
> + struct cdns_pcie_ep *ep = epc_get_drvdata(epc);
> + struct cdns_pcie *pcie = &ep->pcie;
> + u32 r;
> +
> + r = find_first_zero_bit(&ep->ob_region_map, sizeof(ep->ob_region_map));

Second argument must be in bits not bytes.

https://marc.info/?l=linux-pci&m=151179781225513&w=2

> + if (r >= ep->data->max_regions - 1) {
> + dev_err(&epc->dev, "no free outbound region\n");
> + return -EINVAL;
> + }
> +
> + cdns_pcie_set_outbound_region(pcie, r, false, addr, pci_addr, size);
> +
> + set_bit(r, &ep->ob_region_map);
> + ep->ob_addr[r] = addr;
> +
> + return 0;
> +}
> +
> +static void cdns_pcie_ep_unmap_addr(struct pci_epc *epc, phys_addr_t addr)
> +{
> + struct cdns_pcie_ep *ep = epc_get_drvdata(epc);
> + struct cdns_pcie *pcie = &ep->pcie;
> + u32 r;
> +
> + for (r = 0; r < ep->data->max_regions - 1; r++)
> + if (ep->ob_addr[r] == addr)
> + break;
> +
> + if (r >= ep->data->max_regions - 1)

== ?

> + return;
> +
> + cdns_pcie_reset_outbound_region(pcie, r);
> +
> + ep->ob_addr[r] = 0;
> + clear_bit(r, &ep->ob_region_map);
> +}
> +
> +static int cdns_pcie_ep_set_msi(struct pci_epc *epc, u8 mmc)
> +{
> + struct cdns_pcie_ep *ep = epc_get_drvdata(epc);
> + struct cdns_pcie *pcie = &ep->pcie;
> + u32 cap = CDNS_PCIE_EP_FUNC_MSI_CAP_OFFSET;
> + u16 flags;
> + u8 fn = 0;
> +
> + /* Validate the ID of the MSI Capability structure. */
> + if (cdns_pcie_ep_fn_readb(pcie, fn, cap) != PCI_CAP_ID_MSI)
> + return -EINVAL;
> +
> + /*
> + * Set the Multiple Message Capable bitfield into the Message Control
> + * register.
> + */
> + flags = cdns_pcie_ep_fn_readw(pcie, fn, cap + PCI_MSI_FLAGS);
> + flags = (flags & ~PCI_MSI_FLAGS_QMASK) | (mmc << 1);
> + flags |= PCI_MSI_FLAGS_64BIT;
> + flags &= ~PCI_MSI_FLAGS_MASKBIT;
> + cdns_pcie_ep_fn_writew(pcie, fn, cap + PCI_MSI_FLAGS, flags);
> +
> + return 0;
> +}
> +
> +static int cdns_pcie_ep_get_msi(struct pci_epc *epc)
> +{
> + struct cdns_pcie_ep *ep = epc_get_drvdata(epc);
> + struct cdns_pcie *pcie = &ep->pcie;
> + u32 cap = CDNS_PCIE_EP_FUNC_MSI_CAP_OFFSET;
> + u16 flags, mmc, mme;
> + u8 fn = 0;
> +
> + /* Validate the ID of the MSI Capability structure. */
> + if (cdns_pcie_ep_fn_readb(pcie, fn, cap) != PCI_CAP_ID_MSI)
> + return -EINVAL;
> +
> + /* Validate that the MSI feature is actually enabled. */
> + flags = cdns_pcie_ep_fn_readw(pcie, fn, cap + PCI_MSI_FLAGS);
> + if (!(flags & PCI_MSI_FLAGS_ENABLE))
> + return -EINVAL;
> +
> + /*
> + * Get the Multiple Message Enable bitfield from the Message Control
> + * register.
> + */
> + mmc = (flags & PCI_MSI_FLAGS_QMASK) >> 1;
> + mme = (flags & PCI_MSI_FLAGS_QSIZE) >> 4;
> + if (mme > mmc)
> + mme = mmc;
> + if (mme > 5)
> + mme = 5;

You should comment on what this 5 means and why it is fine to cap mme.

> +
> + return mme;
> +}
> +
> +static void cdns_pcie_ep_assert_intx(struct cdns_pcie_ep *ep, u8 fn,
> + u8 intx, bool is_asserted)
> +{
> + struct cdns_pcie *pcie = &ep->pcie;
> + u32 r = ep->data->max_regions - 1;
> + u32 offset;
> + u16 status;
> + u8 msg_code;
> +
> + intx &= 3;
> +
> + /* Set the outbound region if needed. */
> + if (unlikely(ep->irq_pci_addr != CDNS_PCIE_EP_IRQ_PCI_ADDR_LEGACY)) {
> + /* Last region was reserved for IRQ writes. */
> + cdns_pcie_set_outbound_region_for_normal_msg(pcie, r,
> + ep->irq_phys_addr);
> + ep->irq_pci_addr = CDNS_PCIE_EP_IRQ_PCI_ADDR_LEGACY;
> + }
> +
> + if (is_asserted) {
> + ep->irq_pending |= BIT(intx);
> + msg_code = MSG_CODE_ASSERT_INTA + intx;
> + } else {
> + ep->irq_pending &= ~BIT(intx);
> + msg_code = MSG_CODE_DEASSERT_INTA + intx;
> + }
> +
> + status = cdns_pcie_ep_fn_readw(pcie, fn, PCI_STATUS);
> + if (((status & PCI_STATUS_INTERRUPT) != 0) ^ (ep->irq_pending != 0)) {
> + status ^= PCI_STATUS_INTERRUPT;
> + cdns_pcie_ep_fn_writew(pcie, fn, PCI_STATUS, status);
> + }
> +
> + offset = CDNS_PCIE_NORMAL_MSG_ROUTING(MSG_ROUTING_LOCAL) |
> + CDNS_PCIE_NORMAL_MSG_CODE(msg_code) |
> + CDNS_PCIE_MSG_NO_DATA;
> + writel(0, ep->irq_cpu_addr + offset);
> +}
> +
> +static int cdns_pcie_ep_send_legacy_irq(struct cdns_pcie_ep *ep, u8 fn, u8 intx)
> +{
> + u16 cmd;
> +
> + cmd = cdns_pcie_ep_fn_readw(&ep->pcie, fn, PCI_COMMAND);
> + if (cmd & PCI_COMMAND_INTX_DISABLE)
> + return -EINVAL;
> +
> + cdns_pcie_ep_assert_intx(ep, fn, intx, true);
> + mdelay(1);

Add a comment please to explain the mdelay value.

> + cdns_pcie_ep_assert_intx(ep, fn, intx, false);
> + return 0;
> +}
> +
> +static int cdns_pcie_ep_raise_irq(struct pci_epc *epc,
> + enum pci_epc_irq_type type, u8 interrupt_num)
> +{
> + struct cdns_pcie_ep *ep = epc_get_drvdata(epc);
> + struct cdns_pcie *pcie = &ep->pcie;
> + u32 cap = CDNS_PCIE_EP_FUNC_MSI_CAP_OFFSET;
> + u16 flags, mmc, mme, data, data_mask;
> + u8 msi_count;
> + u64 pci_addr, pci_addr_mask = 0xff;
> + u8 fn = 0;
> +
> + /* Handle legacy IRQ. */
> + if (type == PCI_EPC_IRQ_LEGACY)
> + return cdns_pcie_ep_send_legacy_irq(ep, fn, 0);
> +
> + /* Otherwise MSI. */
> + if (type != PCI_EPC_IRQ_MSI)
> + return -EINVAL;
> +
> + /* Check whether the MSI feature has been enabled by the PCI host. */
> + flags = cdns_pcie_ep_fn_readw(pcie, fn, cap + PCI_MSI_FLAGS);
> + if (!(flags & PCI_MSI_FLAGS_ENABLE))
> + return -EINVAL;
> +
> + /* Get the number of enabled MSIs */
> + mmc = (flags & PCI_MSI_FLAGS_QMASK) >> 1;
> + mme = (flags & PCI_MSI_FLAGS_QSIZE) >> 4;
> + if (mme > mmc)
> + mme = mmc;
> + if (mme > 5)
> + mme = 5;

Same comment as above.

> + msi_count = 1 << mme;
> + if (!interrupt_num || interrupt_num > msi_count)
> + return -EINVAL;
> +
> + /* Compute the data value to be written. */
> + data_mask = msi_count - 1;
> + data = cdns_pcie_ep_fn_readw(pcie, fn, cap + PCI_MSI_DATA_64);
> + data = (data & ~data_mask) | ((interrupt_num - 1) & data_mask);
> +
> + /* Get the PCI address where to write the data into. */
> + pci_addr = cdns_pcie_ep_fn_readl(pcie, fn, cap + PCI_MSI_ADDRESS_HI);
> + pci_addr <<= 32;
> + pci_addr |= cdns_pcie_ep_fn_readl(pcie, fn, cap + PCI_MSI_ADDRESS_LO);
> + pci_addr &= GENMASK_ULL(63, 2);
> +
> + /* Set the outbound region if needed. */
> + if (unlikely(ep->irq_pci_addr != pci_addr)) {
> + /* Last region was reserved for IRQ writes. */
> + cdns_pcie_set_outbound_region(pcie, ep->data->max_regions - 1,
> + false,
> + ep->irq_phys_addr,
> + pci_addr & ~pci_addr_mask,
> + pci_addr_mask + 1);
> + ep->irq_pci_addr = pci_addr;
> + }
> + writew(data, ep->irq_cpu_addr + (pci_addr & pci_addr_mask));
> +
> + return 0;
> +}
> +
> +static int cdns_pcie_ep_start(struct pci_epc *epc)
> +{
> + struct cdns_pcie_ep *ep = epc_get_drvdata(epc);
> + struct cdns_pcie *pcie = &ep->pcie;
> + struct pci_epf *epf;
> + u32 cfg;
> + u8 fn = 0;
> +
> + /* Enable this endpoint function. */
> + cfg = cdns_pcie_readl(pcie, CDNS_PCIE_LM_EP_FUNC_CFG);
> + cfg |= BIT(fn);
> + cdns_pcie_writel(pcie, CDNS_PCIE_LM_EP_FUNC_CFG, cfg);
> +
> + /*
> + * Already linked-up: don't call directly pci_epc_linkup() because we've
> + * already locked the epc->lock.
> + */
> + list_for_each_entry(epf, &epc->pci_epf, list)
> + pci_epf_linkup(epf);
> +
> + return 0;
> +}
> +
> +static void cdns_pcie_ep_stop(struct pci_epc *epc)
> +{
> + struct cdns_pcie_ep *ep = epc_get_drvdata(epc);
> + struct cdns_pcie *pcie = &ep->pcie;
> + u32 cfg;
> + u8 fn = 0;
> +
> + /* Disable this endpoint function (function 0 can't be disabled). */

I do not understand this comment and how it applies to the code,
in other words fn is always 0 here (so it can't be disabled)
I do not understand what this code is there for.

> + cfg = cdns_pcie_readl(pcie, CDNS_PCIE_LM_EP_FUNC_CFG);
> + cfg &= ~BIT(fn);
> + cdns_pcie_writel(pcie, CDNS_PCIE_LM_EP_FUNC_CFG, cfg);
> +}
> +
> +static const struct pci_epc_ops cdns_pcie_epc_ops = {
> + .write_header = cdns_pcie_ep_write_header,
> + .set_bar = cdns_pcie_ep_set_bar,
> + .clear_bar = cdns_pcie_ep_clear_bar,
> + .map_addr = cdns_pcie_ep_map_addr,
> + .unmap_addr = cdns_pcie_ep_unmap_addr,
> + .set_msi = cdns_pcie_ep_set_msi,
> + .get_msi = cdns_pcie_ep_get_msi,
> + .raise_irq = cdns_pcie_ep_raise_irq,
> + .start = cdns_pcie_ep_start,
> + .stop = cdns_pcie_ep_stop,
> +};
> +
> +static const struct cdns_pcie_ep_data cdns_pcie_ep_data = {
> + .max_regions = 16,
> +};

As I mentioned in patch 3, should this be set-up with DT ?

Thanks,
Lorenzo

> +
> +static const struct of_device_id cdns_pcie_ep_of_match[] = {
> + { .compatible = "cdns,cdns-pcie-ep",
> + .data = &cdns_pcie_ep_data },
> +
> + { },
> +};
> +
> +static int cdns_pcie_ep_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct device_node *np = dev->of_node;
> + const struct of_device_id *of_id;
> + struct cdns_pcie_ep *ep;
> + struct cdns_pcie *pcie;
> + struct pci_epc *epc;
> + struct resource *res;
> + size_t max_regions;
> + int ret;
> +
> + ep = devm_kzalloc(dev, sizeof(*ep), GFP_KERNEL);
> + if (!ep)
> + return -ENOMEM;
> +
> + platform_set_drvdata(pdev, ep);
> +
> + pcie = &ep->pcie;
> + pcie->is_rc = false;
> +
> + of_id = of_match_node(cdns_pcie_ep_of_match, np);
> + ep->data = (const struct cdns_pcie_ep_data *)of_id->data;
> +
> + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "reg");
> + pcie->reg_base = devm_ioremap_resource(dev, res);
> + if (IS_ERR(pcie->reg_base)) {
> + dev_err(dev, "missing \"reg\"\n");
> + return PTR_ERR(pcie->reg_base);
> + }
> +
> + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mem");
> + if (!res) {
> + dev_err(dev, "missing \"mem\"\n");
> + return -EINVAL;
> + }
> + pcie->mem_res = res;
> +
> + max_regions = ep->data->max_regions;
> + ep->ob_addr = devm_kzalloc(dev, max_regions * sizeof(*ep->ob_addr),
> + GFP_KERNEL);
> + if (!ep->ob_addr)
> + return -ENOMEM;
> +
> + pm_runtime_enable(dev);
> + ret = pm_runtime_get_sync(dev);
> + if (ret < 0) {
> + dev_err(dev, "pm_runtime_get_sync() failed\n");
> + goto err_get_sync;
> + }
> +
> + /* Disable all but function 0 (anyway BIT(0) is hardwired to 1). */
> + cdns_pcie_writel(pcie, CDNS_PCIE_LM_EP_FUNC_CFG, BIT(0));
> +
> + epc = devm_pci_epc_create(dev, &cdns_pcie_epc_ops);
> + if (IS_ERR(epc)) {
> + dev_err(dev, "failed to create epc device\n");
> + ret = PTR_ERR(epc);
> + goto err_init;
> + }
> +
> + ep->epc = epc;
> + epc_set_drvdata(epc, ep);
> +
> + ret = of_property_read_u8(np, "max-functions", &epc->max_functions);
> + if (ret < 0)
> + epc->max_functions = 1;
> +
> + ret = pci_epc_mem_init(epc, pcie->mem_res->start,
> + resource_size(pcie->mem_res));
> + if (ret < 0) {
> + dev_err(dev, "failed to initialize the memory space\n");
> + goto err_init;
> + }
> +
> + ep->irq_cpu_addr = pci_epc_mem_alloc_addr(epc, &ep->irq_phys_addr,
> + SZ_128K);
> + if (!ep->irq_cpu_addr) {
> + dev_err(dev, "failed to reserve memory space for MSI\n");
> + ret = -ENOMEM;
> + goto free_epc_mem;
> + }
> + ep->irq_pci_addr = CDNS_PCIE_EP_IRQ_PCI_ADDR_NONE;
> +
> + return 0;
> +
> + free_epc_mem:
> + pci_epc_mem_exit(epc);
> +
> + err_init:
> + pm_runtime_put_sync(dev);
> +
> + err_get_sync:
> + pm_runtime_disable(dev);
> +
> + return ret;
> +}
> +
> +static struct platform_driver cdns_pcie_ep_driver = {
> + .driver = {
> + .name = "cdns-pcie-ep",
> + .of_match_table = cdns_pcie_ep_of_match,
> + },
> + .probe = cdns_pcie_ep_probe,
> +};
> +builtin_platform_driver(cdns_pcie_ep_driver);
> --
> 2.11.0
>