Re: [PATCH v2 5/6] PCI: rockchip: Add Endpoint controller driver for Rockchip PCIe controller

[cc: Cyrille]

On Fri, Feb 23, 2018 at 09:17:33AM +0800, Shawn Lin wrote:

Well, "Bits" is an understatement here; anyway I think this is
a useless comment so I would remove it.

+ */
+
+#include <linux/kernel.h>
+#include <linux/of.h>
+#include <linux/pci-epc.h>
+#include <linux/platform_device.h>
+#include <linux/sizes.h>
+#include <linux/delay.h>
+#include <linux/configfs.h>
+#include <linux/pci-epf.h>

Nit: Alphabetical order.

+#include "pcie-rockchip.h"
+
+/**
+ * struct rockchip_pcie_ep - private data for PCIe endpoint controller driver
+ * @pcie: Rockchip PCIe controller
+ * @data: pointer to a 'struct rockchip_pcie_data'
+ * @ob_region_map: bitmask of mapped outbound regions
+ * @ob_addr: base addresses in the AXI bus where the outbound regions start
+ * @irq_phys_addr: base address on the AXI bus where the MSI/legacy IRQ
+ *		   dedicated outbound regions is mapped.
+ * @irq_cpu_addr: base address in the CPU space where a write access triggers
+ *		  the sending of a memory write (MSI) / normal message (legacy
+ *		  IRQ) TLP through the PCIe bus.
+ * @irq_pci_addr: used to save the current mapping of the MSI/legacy IRQ
+ *		  dedicated outbound region.
+ * @irq_pci_fn: the latest PCI function that has updated the mapping of
+ *		the MSI/legacy IRQ dedicated outbound region.
+ * @irq_pending: bitmask of asserted legacy IRQs.
+ * @max_regions: maximum number of regions supported by hardware
+ */
+struct rockchip_pcie_ep {
+	rockchip_pcie_epc	pcie;
+	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_pci_fn;
+	u8			irq_pending;
+	u32			max_regions;
+};
+

I think struct cdns_pcie_ep layout (whose content is identical)
is more sensible, follow it.

+void rockchip_pcie_prog_ep_ob_atu(struct rockchip_pcie *rockchip, u8 fn,
+				  u32 r, u32 type, u64 cpu_addr, u64 pci_addr,
+				  size_t size, bool is_clr)
+{
+	u64 sz = 1ULL << fls64(size - 1);
+	int num_pass_bits = ilog2(sz);
+	u32 addr0, addr1, desc0, desc1;
+	bool is_nor_msg = (type == AXI_WRAPPER_NOR_MSG);
+
+	if (is_clr) {
+		rockchip_pcie_write(rockchip, 0,
+				    ROCKCHIP_PCIE_AT_OB_REGION_PCI_ADDR0(r));
+		rockchip_pcie_write(rockchip, 0,
+				    ROCKCHIP_PCIE_AT_OB_REGION_PCI_ADDR1(r));
+		rockchip_pcie_write(rockchip, 0,
+				    ROCKCHIP_PCIE_AT_OB_REGION_DESC0(r));
+		rockchip_pcie_write(rockchip, 0,
+				    ROCKCHIP_PCIE_AT_OB_REGION_DESC1(r));
+		rockchip_pcie_write(rockchip, 0,
+				    ROCKCHIP_PCIE_AT_OB_REGION_CPU_ADDR0(r));
+		rockchip_pcie_write(rockchip, 0,
+				    ROCKCHIP_PCIE_AT_OB_REGION_CPU_ADDR1(r));
+		return;
+	}

You can split the (is_clr) path in a separate function, say:

rockchip_pcie_clear_ep_ob_atu()

it would simplify this one.

+
+	/* The minimal region size is 1MB */
+	if (num_pass_bits < 8)
+		num_pass_bits = 8;
+
+	cpu_addr -= rockchip->mem_res->start;
+	addr0 = ((is_nor_msg ? 0x10 : (num_pass_bits - 1)) &
+		PCIE_CORE_OB_REGION_ADDR0_NUM_BITS) |
+		(lower_32_bits(cpu_addr) & PCIE_CORE_OB_REGION_ADDR0_LO_ADDR);
+	addr1 = upper_32_bits(is_nor_msg ? cpu_addr : pci_addr);
+	desc0 = ROCKCHIP_PCIE_AT_OB_REGION_DESC0_DEVFN(fn) | type;
+	desc1 = 0;
+
+	if (is_nor_msg) {
+		rockchip_pcie_write(rockchip, 0,
+				    ROCKCHIP_PCIE_AT_OB_REGION_PCI_ADDR0(r));
+		rockchip_pcie_write(rockchip, 0,
+				    ROCKCHIP_PCIE_AT_OB_REGION_PCI_ADDR1(r));
+		rockchip_pcie_write(rockchip, desc0,
+				    ROCKCHIP_PCIE_AT_OB_REGION_DESC0(r));
+		rockchip_pcie_write(rockchip, desc1,
+				    ROCKCHIP_PCIE_AT_OB_REGION_DESC1(r));
+	} else {
+		/* PCI bus address region */
+		rockchip_pcie_write(rockchip, addr0,
+				    ROCKCHIP_PCIE_AT_OB_REGION_PCI_ADDR0(r));
+		rockchip_pcie_write(rockchip, addr1,
+				    ROCKCHIP_PCIE_AT_OB_REGION_PCI_ADDR1(r));
+		rockchip_pcie_write(rockchip, desc0,
+				    ROCKCHIP_PCIE_AT_OB_REGION_DESC0(r));
+		rockchip_pcie_write(rockchip, desc1,
+				    ROCKCHIP_PCIE_AT_OB_REGION_DESC1(r));
+
+		addr0 =
+		    ((num_pass_bits - 1) & PCIE_CORE_OB_REGION_ADDR0_NUM_BITS) |
+		    (lower_32_bits(cpu_addr) &
+		     PCIE_CORE_OB_REGION_ADDR0_LO_ADDR);
+		addr1 = upper_32_bits(cpu_addr);
+	}
+
+	/* CPU bus address region */
+	rockchip_pcie_write(rockchip, addr0,
+			    ROCKCHIP_PCIE_AT_OB_REGION_CPU_ADDR0(r));
+	rockchip_pcie_write(rockchip, addr1,
+			    ROCKCHIP_PCIE_AT_OB_REGION_CPU_ADDR1(r));
+}
+
+static int rockchip_pcie_ep_write_header(struct pci_epc *epc, u8 fn,
+					 struct pci_epf_header *hdr)
+{
+	struct rockchip_pcie_ep *ep = epc_get_drvdata(epc);
+	struct rockchip_pcie *rockchip = &ep->pcie;
+
+	/* All functions share the same vendor ID with function 0 */
+	if (fn == 0) {
+		u32 vid_regs = (hdr->vendorid & GENMASK(15, 0)) |
+			       (hdr->subsys_vendor_id & GENMASK(31, 16)) << 16;
+
+		rockchip_pcie_write(rockchip, vid_regs,
+				    PCIE_CORE_CONFIG_VENDOR);
+	}
+
+	rockchip_pcie_write(rockchip, hdr->deviceid << 16,
+			    ROCKCHIP_PCIE_EP_FUNC_BASE(fn) + PCI_VENDOR_ID);
+
+	rockchip_pcie_write(rockchip,
+			    hdr->revid |
+			    hdr->progif_code << 8 |
+			    hdr->subclass_code << 16 |
+			    hdr->baseclass_code << 24,
+			    ROCKCHIP_PCIE_EP_FUNC_BASE(fn) + PCI_REVISION_ID);
+	rockchip_pcie_write(rockchip, hdr->cache_line_size,
+			    ROCKCHIP_PCIE_EP_FUNC_BASE(fn) +
+			    PCI_CACHE_LINE_SIZE);
+	rockchip_pcie_write(rockchip, hdr->subsys_id << 16,
+			    ROCKCHIP_PCIE_EP_FUNC_BASE(fn) +
+			    PCI_SUBSYSTEM_VENDOR_ID);
+	rockchip_pcie_write(rockchip, hdr->interrupt_pin << 8,
+			    ROCKCHIP_PCIE_EP_FUNC_BASE(fn) +
+			    PCI_INTERRUPT_LINE);
+
+	return 0;
+

Useless empty line.

+}
+
+static int rockchip_pcie_ep_set_bar(struct pci_epc *epc, u8 fn,
+				    enum pci_barno bar, dma_addr_t bar_phys,
+				    size_t size, int flags)
+{
+	struct rockchip_pcie_ep *ep = epc_get_drvdata(epc);
+	struct rockchip_pcie *rockchip = &ep->pcie;
+	u32 addr0, addr1, reg, cfg, b, aperture, ctrl;
+	u64 sz;
+
+	/* BAR size is 2^(aperture + 7) */
+	sz = max_t(size_t, size, MIN_EP_APERTURE);
+
+	/*
+	 * roundup_pow_of_two() returns an unsigned long, which is not suited
+	 * for 64bit values.
+	 */
+	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 = ROCKCHIP_PCIE_CORE_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;
+
+		if (is_64bits && is_prefetch)
+			ctrl =
+			    ROCKCHIP_PCIE_CORE_BAR_CFG_CTRL_PREFETCH_MEM_64BITS;
+		else if (is_prefetch)
+			ctrl =
+			    ROCKCHIP_PCIE_CORE_BAR_CFG_CTRL_PREFETCH_MEM_32BITS;
+		else if (is_64bits)
+			ctrl = ROCKCHIP_PCIE_CORE_BAR_CFG_CTRL_MEM_64BITS;
+		else
+			ctrl = ROCKCHIP_PCIE_CORE_BAR_CFG_CTRL_MEM_32BITS;
+	}
+
+	if (bar < BAR_4) {
+		reg = ROCKCHIP_PCIE_CORE_EP_FUNC_BAR_CFG0(fn);
+		b = bar;
+	} else {
+		reg = ROCKCHIP_PCIE_CORE_EP_FUNC_BAR_CFG1(fn);
+		b = bar - BAR_4;
+	}
+
+	addr0 = lower_32_bits(bar_phys);
+	addr1 = upper_32_bits(bar_phys);
+
+	cfg = rockchip_pcie_read(rockchip, reg);
+	cfg &= ~(ROCKCHIP_PCIE_CORE_EP_FUNC_BAR_CFG_BAR_APERTURE_MASK(b) |
+		 ROCKCHIP_PCIE_CORE_EP_FUNC_BAR_CFG_BAR_CTRL_MASK(b));
+	cfg |= (ROCKCHIP_PCIE_CORE_EP_FUNC_BAR_CFG_BAR_APERTURE(b, aperture) |
+		ROCKCHIP_PCIE_CORE_EP_FUNC_BAR_CFG_BAR_CTRL(b, ctrl));
+
+	rockchip_pcie_write(rockchip, cfg, reg);
+	rockchip_pcie_write(rockchip, addr0,
+			    ROCKCHIP_PCIE_AT_IB_EP_FUNC_BAR_ADDR0(fn, bar));
+	rockchip_pcie_write(rockchip, addr1,
+			    ROCKCHIP_PCIE_AT_IB_EP_FUNC_BAR_ADDR1(fn, bar));
+
+	return 0;
+}
+
+static void rockchip_pcie_ep_clear_bar(struct pci_epc *epc, u8 fn,
+				       enum pci_barno bar)
+{
+	struct rockchip_pcie_ep *ep = epc_get_drvdata(epc);
+	struct rockchip_pcie *rockchip = &ep->pcie;
+	u32 reg, cfg, b, ctrl;
+
+	if (bar < BAR_4) {
+		reg = ROCKCHIP_PCIE_CORE_EP_FUNC_BAR_CFG0(fn);
+		b = bar;
+	} else {
+		reg = ROCKCHIP_PCIE_CORE_EP_FUNC_BAR_CFG1(fn);
+		b = bar - BAR_4;
+	}
+
+	ctrl = ROCKCHIP_PCIE_CORE_BAR_CFG_CTRL_DISABLED;
+	cfg = rockchip_pcie_read(rockchip, reg);
+	cfg &= ~(ROCKCHIP_PCIE_CORE_EP_FUNC_BAR_CFG_BAR_APERTURE_MASK(b) |
+		 ROCKCHIP_PCIE_CORE_EP_FUNC_BAR_CFG_BAR_CTRL_MASK(b));
+	cfg |= ROCKCHIP_PCIE_CORE_EP_FUNC_BAR_CFG_BAR_CTRL(b, ctrl);
+
+	rockchip_pcie_write(rockchip, cfg, reg);
+	rockchip_pcie_write(rockchip, 0x0,
+			    ROCKCHIP_PCIE_AT_IB_EP_FUNC_BAR_ADDR0(fn, bar));
+	rockchip_pcie_write(rockchip, 0x0,
+			    ROCKCHIP_PCIE_AT_IB_EP_FUNC_BAR_ADDR1(fn, bar));
+

Useless empty line.

+}
+
+static int rockchip_pcie_ep_map_addr(struct pci_epc *epc, u8 fn,
+				     phys_addr_t addr, u64 pci_addr,
+				     size_t size)
+{
+	struct rockchip_pcie_ep *ep = epc_get_drvdata(epc);
+	struct rockchip_pcie *pcie = &ep->pcie;
+	u32 r;
+
+	r = find_first_zero_bit(&ep->ob_region_map,
+				sizeof(ep->ob_region_map) * BITS_PER_LONG);
+	if (r >= ep->max_regions - 1) {

Why are we comparing for equality against (max_regions - 1) ? Aren't
we leaving a region out ?

NB: I know this code is identical to the Cadence driver but copy and
paste is not a good reason for it and if that's a bug it ought to be
fixed in both drivers.

+		dev_err(&epc->dev, "no free outbound region\n");
+		return -EINVAL;
+	}
+
+	rockchip_pcie_prog_ep_ob_atu(pcie, fn, r, AXI_WRAPPER_MEM_WRITE, addr,
+				     pci_addr, size, false);
+
+	set_bit(r, &ep->ob_region_map);
+	ep->ob_addr[r] = addr;
+
+	return 0;
+

Useless empty line.

+}
+
+static void rockchip_pcie_ep_unmap_addr(struct pci_epc *epc, u8 fn,
+					phys_addr_t addr)
+{
+	struct rockchip_pcie_ep *ep = epc_get_drvdata(epc);
+	struct rockchip_pcie *rockchip = &ep->pcie;
+	u32 r;
+
+	for (r = 0; r < ep->max_regions - 1; r++)
+		if (ep->ob_addr[r] == addr)
+			break;

See above for max_regions - 1.

+
+	if (r == ep->max_regions - 1)
+		return;

Ditto.

+
+	rockchip_pcie_prog_ep_ob_atu(rockchip, 0, 0, 0, 0, 0, 0, true);
+
+	ep->ob_addr[r] = 0;
+	clear_bit(r, &ep->ob_region_map);
+}
+
+static int rockchip_pcie_ep_set_msi(struct pci_epc *epc, u8 fn,
+				    u8 multi_msg_cap)
+{
+	struct rockchip_pcie_ep *ep = epc_get_drvdata(epc);
+	struct rockchip_pcie *rockchip = &ep->pcie;
+	u16 flags;
+
+	flags = rockchip_pcie_read(rockchip,
+				   ROCKCHIP_PCIE_EP_FUNC_BASE(fn) +
+				   ROCKCHIP_PCIE_EP_MSI_CTRL_REG);
+	flags &= ~ROCKCHIP_PCIE_EP_MSI_CTRL_MMC_MASK;
+	flags |=
+	   ((multi_msg_cap << 1) <<  ROCKCHIP_PCIE_EP_MSI_CTRL_MMC_OFFSET) |
+	   PCI_MSI_FLAGS_64BIT;
+	flags &= ~ROCKCHIP_PCIE_EP_MSI_CTRL_MASK_MSI_CAP;
+	rockchip_pcie_write(rockchip, flags,
+			    ROCKCHIP_PCIE_EP_FUNC_BASE(fn) +
+			    ROCKCHIP_PCIE_EP_MSI_CTRL_REG);
+	return 0;
+}
+
+static int rockchip_pcie_ep_get_msi(struct pci_epc *epc, u8 fn)
+{
+	struct rockchip_pcie_ep *ep = epc_get_drvdata(epc);
+	struct rockchip_pcie *rockchip = &ep->pcie;
+	u16 flags;
+
+	flags = rockchip_pcie_read(rockchip,
+				   ROCKCHIP_PCIE_EP_FUNC_BASE(fn) +
+				   ROCKCHIP_PCIE_EP_MSI_CTRL_REG);
+	if (!(flags & ROCKCHIP_PCIE_EP_MSI_CTRL_ME))
+		return -EINVAL;
+
+	return ((flags & ROCKCHIP_PCIE_EP_MSI_CTRL_MME_MASK) >>
+			ROCKCHIP_PCIE_EP_MSI_CTRL_MME_OFFSET);
+}
+
+static void rockchip_pcie_ep_assert_intx(struct rockchip_pcie_ep *ep, u8 fn,
+					 u8 intx, bool is_asserted)
+{
+	struct rockchip_pcie *rockchip = &ep->pcie;
+	u32 r = ep->max_regions - 1;
+	u32 offset;
+	u16 status;
+	u8 msg_code;
+
+	if (unlikely(ep->irq_pci_addr != ROCKCHIP_PCIE_EP_PCI_LEGACY_IRQ_ADDR ||
+		     ep->irq_pci_fn != fn)) {
+		rockchip_pcie_prog_ep_ob_atu(rockchip, fn, r,
+					     AXI_WRAPPER_NOR_MSG,
+					     ep->irq_phys_addr, 0, 0, false);
+		ep->irq_pci_addr = ROCKCHIP_PCIE_EP_PCI_LEGACY_IRQ_ADDR;
+		ep->irq_pci_fn = fn;
+	}
+
+	intx &= 3;
+	if (is_asserted) {
+		ep->irq_pending |= BIT(intx);
+		msg_code = ROCKCHIP_PCIE_MSG_CODE_ASSERT_INTA + intx;
+	} else {
+		ep->irq_pending &= ~BIT(intx);
+		msg_code = ROCKCHIP_PCIE_MSG_CODE_DEASSERT_INTA + intx;
+	}
+
+	status = rockchip_pcie_read(rockchip,
+				    ROCKCHIP_PCIE_EP_FUNC_BASE(fn) +
+				    ROCKCHIP_PCIE_EP_CMD_STATUS);
+	status &= ROCKCHIP_PCIE_EP_CMD_STATUS_IS;
+
+	if ((status != 0) ^ (ep->irq_pending != 0)) {
+		status ^= ROCKCHIP_PCIE_EP_CMD_STATUS_IS;
+		rockchip_pcie_write(rockchip, status,
+				    ROCKCHIP_PCIE_EP_FUNC_BASE(fn) +
+				    ROCKCHIP_PCIE_EP_CMD_STATUS);
+	}
+
+	offset =
+	   ROCKCHIP_PCIE_MSG_ROUTING(ROCKCHIP_PCIE_MSG_ROUTING_LOCAL_INTX) |
+	   ROCKCHIP_PCIE_MSG_CODE(msg_code) | ROCKCHIP_PCIE_MSG_NO_DATA;
+	writel(0, ep->irq_cpu_addr + offset);
+}
+
+static int rockchip_pcie_ep_send_legacy_irq(struct rockchip_pcie_ep *ep, u8 fn,
+					    u8 intx)
+{
+	u16 cmd;
+
+	cmd = rockchip_pcie_read(&ep->pcie,
+				 ROCKCHIP_PCIE_EP_FUNC_BASE(fn) +
+				 ROCKCHIP_PCIE_EP_CMD_STATUS);
+
+	if (cmd & PCI_COMMAND_INTX_DISABLE)
+		return -EINVAL;
+
+	rockchip_pcie_ep_assert_intx(ep, fn, intx, true);
+	mdelay(1);

Is there some HW engineering backing this mdelay() value ? That's a
question for Cadence driver too.

+	rockchip_pcie_ep_assert_intx(ep, fn, intx, false);
+	return 0;
+}
+
+static int rockchip_pcie_ep_send_msi_irq(struct rockchip_pcie_ep *ep, u8 fn,
+					 u8 interrupt_num)
+{
+	struct rockchip_pcie *rockchip = &ep->pcie;
+	u16 flags, mme, data, data_mask;
+	u8 msi_count;
+	u64 pci_addr, pci_addr_mask = 0xff;
+
+	/* Check MSI enable bit */
+	flags = rockchip_pcie_read(&ep->pcie,
+				   ROCKCHIP_PCIE_EP_FUNC_BASE(fn) +
+				   ROCKCHIP_PCIE_EP_MSI_CTRL_REG);
+	if (!(flags & ROCKCHIP_PCIE_EP_MSI_CTRL_ME))
+		return -EINVAL;
+
+	/* Get MSI numbers from MME */
+	mme = ((flags & ROCKCHIP_PCIE_EP_MSI_CTRL_MME_MASK) >>
+			ROCKCHIP_PCIE_EP_MSI_CTRL_MME_OFFSET);
+	msi_count = 1 << mme;
+	if (!interrupt_num || interrupt_num > msi_count)
+		return -EINVAL;
+
+	/* Set MSI private data */
+	data_mask = msi_count - 1;
+	data = rockchip_pcie_read(rockchip,
+				  ROCKCHIP_PCIE_EP_FUNC_BASE(fn) +
+				  ROCKCHIP_PCIE_EP_MSI_CTRL_REG +
+				  PCI_MSI_DATA_64);
+	data = (data & ~data_mask) | ((interrupt_num - 1) & data_mask);
+
+	/* Get MSI PCI address */
+	pci_addr = rockchip_pcie_read(rockchip,
+				      ROCKCHIP_PCIE_EP_FUNC_BASE(fn) +
+				      ROCKCHIP_PCIE_EP_MSI_CTRL_REG +
+				      PCI_MSI_ADDRESS_HI);
+	pci_addr <<= 32;
+	pci_addr |= rockchip_pcie_read(rockchip,
+				       ROCKCHIP_PCIE_EP_FUNC_BASE(fn) +
+				       ROCKCHIP_PCIE_EP_MSI_CTRL_REG +
+				       PCI_MSI_ADDRESS_LO);
+	pci_addr &= GENMASK_ULL(63, 2);
+
+	/* Set the outbound region if needed. */
+	if (unlikely(ep->irq_pci_addr != (pci_addr & ~pci_addr_mask) ||
+		     ep->irq_pci_fn != fn)) {
+		rockchip_pcie_prog_ep_ob_atu(rockchip, fn, ep->max_regions - 1,
+					     AXI_WRAPPER_MEM_WRITE,
+					     ep->irq_phys_addr,
+					     pci_addr & ~pci_addr_mask,
+					     pci_addr_mask + 1, false);
+		ep->irq_pci_addr = (pci_addr & ~pci_addr_mask);
+		ep->irq_pci_fn = fn;
+	}
+
+	writew(data, ep->irq_cpu_addr + (pci_addr & pci_addr_mask));
+	return 0;
+}
+
+

Useless empty line.

+static int rockchip_pcie_ep_raise_irq(struct pci_epc *epc, u8 fn,
+				      enum pci_epc_irq_type type,
+				      u8 interrupt_num)
+{
+	struct rockchip_pcie_ep *ep = epc_get_drvdata(epc);
+
+	switch (type) {
+	case PCI_EPC_IRQ_LEGACY:
+		return rockchip_pcie_ep_send_legacy_irq(ep, fn, 0);

Why always INTA (question valid on Cadence driver too) ?

+	case PCI_EPC_IRQ_MSI:
+		return rockchip_pcie_ep_send_msi_irq(ep, fn, interrupt_num);
+	default:
+		return -EINVAL;
+	}
+}
+
+static int rockchip_pcie_ep_start(struct pci_epc *epc)
+{
+	struct rockchip_pcie_ep *ep = epc_get_drvdata(epc);
+	struct rockchip_pcie *rockchip = &ep->pcie;
+	struct pci_epf *epf;
+	u32 cfg;
+
+	cfg = BIT(0);
+	list_for_each_entry(epf, &epc->pci_epf, list)
+		cfg |= BIT(epf->func_no);
+
+	rockchip_pcie_write(rockchip, cfg, PCIE_CORE_PHY_FUNC_CFG);
+
+	list_for_each_entry(epf, &epc->pci_epf, list)
+		pci_epf_linkup(epf);
+
+	return 0;
+}
+
+static const struct pci_epc_ops rockchip_pcie_epc_ops = {
+	.write_header	= rockchip_pcie_ep_write_header,
+	.set_bar	= rockchip_pcie_ep_set_bar,
+	.clear_bar	= rockchip_pcie_ep_clear_bar,
+	.map_addr	= rockchip_pcie_ep_map_addr,
+	.unmap_addr	= rockchip_pcie_ep_unmap_addr,
+	.set_msi	= rockchip_pcie_ep_set_msi,
+	.get_msi	= rockchip_pcie_ep_get_msi,
+	.raise_irq	= rockchip_pcie_ep_raise_irq,
+	.start		= rockchip_pcie_ep_start,
+};
+
+/**
+ * rockchip_pcie_parse_dt - Parse Device Tree
+ * @rockchip: PCIe port information

Missing a parameter. By the way a kerneldoc for this entry does
not seem that useful to me, you can remove it.

+ *
+ * Return: '0' on success and error value on failure
+ */
+static int rockchip_pcie_parse_ep_dt(struct rockchip_pcie *rockchip,
+				     struct rockchip_pcie_ep *ep)
+{
+	struct device *dev = rockchip->dev;
+	int err;
+
+	err = rockchip_pcie_parse_dt(rockchip);
+	if (err)
+		return err;
+
+	err = rockchip_pcie_get_phys(rockchip);
+	if (err)
+		return err;
+
+	err = of_property_read_u32(dev->of_node,
+				   "rockchip,max-outbound-regions",
+				   &ep->max_regions);
+	if (err < 0 || ep->max_regions > MAX_REGION_LIMIT)
+		ep->max_regions = MAX_REGION_LIMIT;
+
+	err = of_property_read_u8(dev->of_node, "max-functions",
+				  &ep->epc->max_functions);
+	if (err < 0)
+		ep->epc->max_functions = 1;
+
+	return 0;
+}
+
+static const struct of_device_id rockchip_pcie_ep_of_match[] = {
+	{ .compatible = "rockchip,rk3399-pcie-ep"},
+	{},
+};
+
+static int rockchip_pcie_ep_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct rockchip_pcie_ep *ep;
+	rockchip_pcie_epc *rockchip;
+	struct pci_epc *epc;
+	size_t max_regions;
+	int err;
+
+	ep = devm_kzalloc(dev, sizeof(*ep), GFP_KERNEL);
+	if (!ep)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, ep);

What's this used for ?

+	rockchip = &ep->pcie;
+	rockchip->is_rc = false;
+	rockchip->dev = dev;
+
+	epc = devm_pci_epc_create(dev, &rockchip_pcie_epc_ops);
+	if (IS_ERR(epc)) {
+		dev_err(dev, "failed to create epc device\n");
+		return PTR_ERR(epc);
+	}
+
+	ep->epc = epc;
+	epc_set_drvdata(epc, ep);
+
+	err = rockchip_pcie_parse_ep_dt(rockchip, ep);
+	if (err)
+		return err;
+
+	err = rockchip_pcie_enable_clocks(rockchip);
+	if (err)
+		return err;
+
+	err = rockchip_pcie_init_port(rockchip);
+	if (err)
+		goto err_disable_clocks;
+
+	/* Establish the link automatically */
+	rockchip_pcie_write(rockchip, PCIE_CLIENT_LINK_TRAIN_ENABLE,
+			    PCIE_CLIENT_CONFIG);
+
+	max_regions = ep->max_regions;
+	ep->ob_addr = devm_kzalloc(dev, max_regions * sizeof(*ep->ob_addr),
+				   GFP_KERNEL);
+
+	if (!ep->ob_addr) {
+		err = -ENOMEM;
+		goto err_uninit_port;
+	}
+
+	/* Only enable function 0 by default */
+	rockchip_pcie_write(rockchip, BIT(0), PCIE_CORE_PHY_FUNC_CFG);
+
+

Useless empty line.

[...]

+typedef struct rockchip_pcie rockchip_pcie_epc;

This typedef has no justification and just obfuscates, please remove it.

Thanks,
Lorenzo