pci_ep: add Cadence PCIe endpoint driver

Add Cadence PCIe endpoint driver supporting configuration
of header, bars and MSI for device.

Signed-off-by: Ramon Fried <ramon.fried@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/pci_endpoint/pcie-cadence-ep.c b/drivers/pci_endpoint/pcie-cadence-ep.c
new file mode 100644
index 0000000..59231d3
--- /dev/null
+++ b/drivers/pci_endpoint/pcie-cadence-ep.c
@@ -0,0 +1,177 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2019
+ * Written by Ramon Fried <ramon.fried@gmail.com>
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <pci_ep.h>
+#include <linux/sizes.h>
+#include <linux/log2.h>
+#include "pcie-cadence.h"
+
+DECLARE_GLOBAL_DATA_PTR;
+
+static int cdns_write_header(struct udevice *dev, uint fn,
+			     struct pci_ep_header *hdr)
+{
+	struct cdns_pcie *pcie = dev_get_priv(dev);
+
+	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);
+
+	/*
+	 * Vendor ID can only be modified from function 0, all other functions
+	 * use the same vendor ID as function 0.
+	 */
+	if (fn == 0) {
+		/* Update the vendor IDs. */
+		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);
+	}
+
+	return 0;
+}
+
+static int cdns_set_bar(struct udevice *dev, uint fn, struct pci_bar *ep_bar)
+{
+	struct cdns_pcie *pcie = dev_get_priv(dev);
+	dma_addr_t bar_phys = ep_bar->phys_addr;
+	enum pci_barno bar = ep_bar->barno;
+	int flags = ep_bar->flags;
+	u32 addr0, addr1, reg, cfg, b, aperture, ctrl;
+	u64 sz;
+
+	/* BAR size is 2^(aperture + 7) */
+	sz = max_t(size_t, ep_bar->size, CDNS_PCIE_EP_MIN_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 = CDNS_PCIE_LM_BAR_CFG_CTRL_IO_32BITS;
+	} else {
+		bool is_prefetch = !!(flags & PCI_BASE_ADDRESS_MEM_PREFETCH);
+		bool is_64bits = (sz > SZ_2G) |
+			!!(ep_bar->flags & PCI_BASE_ADDRESS_MEM_TYPE_64);
+
+		if (is_64bits && (bar & 1))
+			return -EINVAL;
+
+		if (is_64bits && !(flags & PCI_BASE_ADDRESS_MEM_TYPE_64))
+			ep_bar->flags |= PCI_BASE_ADDRESS_MEM_TYPE_64;
+
+		if (is_64bits && is_prefetch)
+			ctrl = CDNS_PCIE_LM_BAR_CFG_CTRL_PREFETCH_MEM_64BITS;
+		else if (is_prefetch)
+			ctrl = CDNS_PCIE_LM_BAR_CFG_CTRL_PREFETCH_MEM_32BITS;
+		else if (is_64bits)
+			ctrl = CDNS_PCIE_LM_BAR_CFG_CTRL_MEM_64BITS;
+		else
+			ctrl = CDNS_PCIE_LM_BAR_CFG_CTRL_MEM_32BITS;
+	}
+
+	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);
+
+	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 int cdns_set_msi(struct udevice *dev, uint fn, uint mmc)
+{
+	struct cdns_pcie *pcie = dev_get_priv(dev);
+	u32 cap = CDNS_PCIE_EP_FUNC_MSI_CAP_OFFSET;
+
+	/*
+	 * Set the Multiple Message Capable bitfield into the Message Control
+	 * register.
+	 */
+	u16 flags;
+
+	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 struct pci_ep_ops cdns_pci_ep_ops = {
+	.write_header = cdns_write_header,
+	.set_bar = cdns_set_bar,
+	.set_msi = cdns_set_msi,
+};
+
+static int cdns_pci_ep_probe(struct udevice *dev)
+{
+	struct cdns_pcie *pdata = dev_get_priv(dev);
+
+	pdata->reg_base = (void __iomem *)devfdt_get_addr(dev);
+	if (!pdata->reg_base)
+		return -ENOMEM;
+
+	pdata->max_functions = fdtdec_get_int(gd->fdt_blob, dev_of_offset(dev),
+					      "max-functions", 1);
+	pdata->max_regions = fdtdec_get_int(gd->fdt_blob, dev_of_offset(dev),
+					    "cdns,max-outbound-regions", 8);
+
+	return 0;
+}
+
+static int cdns_pci_ep_remove(struct udevice *dev)
+{
+	return 0;
+}
+
+const struct udevice_id cadence_pci_ep_of_match[] = {
+	{ .compatible = "cdns,cdns-pcie-ep" },
+	{ }
+};
+
+U_BOOT_DRIVER(cdns_pcie) = {
+	.name	= "cdns,pcie-ep",
+	.id	= UCLASS_PCI_EP,
+	.of_match = cadence_pci_ep_of_match,
+	.ops = &cdns_pci_ep_ops,
+	.probe = cdns_pci_ep_probe,
+	.remove = cdns_pci_ep_remove,
+	.priv_auto_alloc_size = sizeof(struct cdns_pcie),
+};