drivers: pci_ep: Introduce UCLASS_PCI_EP uclass

Introduce new UCLASS_PCI_EP class for handling PCI endpoint
devices, allowing to set various attributes of the PCI endpoint
device, such as:
* configuration space header
* BAR definitions
* outband memory mapping
* start/stop PCI link

Signed-off-by: Ramon Fried <ramon.fried@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

drivers/Kconfig

@@ -66,6 +66,8 @@ source "drivers/nvme/Kconfig"
 
 source "drivers/pci/Kconfig"
 
+source "drivers/pci_endpoint/Kconfig"
+
 source "drivers/pch/Kconfig"
 
 source "drivers/pcmcia/Kconfig"

drivers/Makefile

@@ -86,6 +86,7 @@ obj-$(CONFIG_FPGA) += fpga/
 obj-y += misc/
 obj-$(CONFIG_MMC) += mmc/
 obj-$(CONFIG_NVME) += nvme/
+obj-$(CONFIG_PCI_ENDPOINT) += pci_endpoint/
 obj-y += pcmcia/
 obj-y += dfu/
 obj-$(CONFIG_PCH) += pch/

drivers/pci_endpoint/Kconfig

@@ -0,0 +1,17 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# PCI Endpoint Support
+#
+
+menu "PCI Endpoint"
+
+config PCI_ENDPOINT
+	bool "PCI Endpoint Support"
+	depends on DM
+	help
+	   Enable this configuration option to support configurable PCI
+	   endpoints. This should be enabled if the platform has a PCI
+	   controllers that can operate in endpoint mode (as a device
+	   connected to PCI host or bridge).
+
+endmenu

drivers/pci_endpoint/Makefile

@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0+
+#
+# (C) Copyright 2019
+# Ramon Fried <ramon.fried@gmail.com>
+
+obj-y += pci_ep-uclass.o

drivers/pci_endpoint/pci_ep-uclass.c

@@ -0,0 +1,211 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * PCI Endpoint uclass
+ *
+ * Based on Linux PCI-EP driver written by
+ * Kishon Vijay Abraham I <kishon@ti.com>
+ *
+ * Copyright (c) 2019
+ * Written by Ramon Fried <ramon.fried@gmail.com>
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <linux/log2.h>
+#include <pci_ep.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+int pci_ep_write_header(struct udevice *dev, uint fn, struct pci_ep_header *hdr)
+{
+	struct pci_ep_ops *ops = pci_ep_get_ops(dev);
+
+	if (!ops->write_header)
+		return -ENOSYS;
+
+	return ops->write_header(dev, fn, hdr);
+}
+
+int pci_ep_read_header(struct udevice *dev, uint fn, struct pci_ep_header *hdr)
+{
+	struct pci_ep_ops *ops = pci_ep_get_ops(dev);
+
+	if (!ops->read_header)
+		return -ENOSYS;
+
+	return ops->read_header(dev, fn, hdr);
+}
+
+int pci_ep_set_bar(struct udevice *dev, uint func_no, struct pci_bar *ep_bar)
+{
+	struct pci_ep_ops *ops = pci_ep_get_ops(dev);
+	int flags = ep_bar->flags;
+
+	/* Some basic bar validity checks */
+	if (ep_bar->barno > BAR_5 || ep_bar < BAR_0)
+		return -EINVAL;
+
+	if ((ep_bar->barno == BAR_5 &&
+	     (flags & PCI_BASE_ADDRESS_MEM_TYPE_64)) ||
+	    ((flags & PCI_BASE_ADDRESS_SPACE_IO) &&
+	     (flags & PCI_BASE_ADDRESS_IO_MASK)) ||
+	    (upper_32_bits(ep_bar->size) &&
+	     !(flags & PCI_BASE_ADDRESS_MEM_TYPE_64)))
+		return -EINVAL;
+
+	if (!ops->set_bar)
+		return -ENOSYS;
+
+	return ops->set_bar(dev, func_no, ep_bar);
+}
+
+int pci_ep_read_bar(struct udevice *dev, uint func_no, struct pci_bar *ep_bar,
+		    enum pci_barno barno)
+{
+	struct pci_ep_ops *ops = pci_ep_get_ops(dev);
+
+	/* Some basic bar validity checks */
+	if (barno > BAR_5 || barno < BAR_0)
+		return -EINVAL;
+
+	if (!ops->read_bar)
+		return -ENOSYS;
+
+	return ops->read_bar(dev, func_no, ep_bar, barno);
+}
+
+int pci_ep_clear_bar(struct udevice *dev, uint func_num, enum pci_barno bar)
+{
+	struct pci_ep_ops *ops = pci_ep_get_ops(dev);
+
+	if (!ops->clear_bar)
+		return -ENOSYS;
+
+	return ops->clear_bar(dev, func_num, bar);
+}
+
+int pci_ep_map_addr(struct udevice *dev, uint func_no, phys_addr_t addr,
+		    u64 pci_addr, size_t size)
+{
+	struct pci_ep_ops *ops = pci_ep_get_ops(dev);
+
+	if (!ops->map_addr)
+		return -ENOSYS;
+
+	return ops->map_addr(dev, func_no, addr, pci_addr, size);
+}
+
+int pci_ep_unmap_addr(struct udevice *dev, uint func_no, phys_addr_t addr)
+{
+	struct pci_ep_ops *ops = pci_ep_get_ops(dev);
+
+	if (!ops->unmap_addr)
+		return -ENOSYS;
+
+	return ops->unmap_addr(dev, func_no, addr);
+}
+
+int pci_ep_set_msi(struct udevice *dev, uint func_no, uint interrupts)
+{
+	struct pci_ep_ops *ops = pci_ep_get_ops(dev);
+	uint encode_int;
+
+	if (interrupts > 32)
+		return -EINVAL;
+
+	if (!ops->set_msi)
+		return -ENOSYS;
+
+	/* MSI spec permits allocation of
+	 * only 1, 2, 4, 8, 16, 32 interrupts
+	 */
+	encode_int = order_base_2(interrupts);
+
+	return ops->set_msi(dev, func_no, encode_int);
+}
+
+int pci_ep_get_msi(struct udevice *dev, uint func_no)
+{
+	struct pci_ep_ops *ops = pci_ep_get_ops(dev);
+	int interrupt;
+
+	if (!ops->get_msi)
+		return -ENOSYS;
+
+	interrupt = ops->get_msi(dev, func_no);
+
+	if (interrupt < 0)
+		return 0;
+
+	/* Translate back from order base 2*/
+	interrupt = 1 << interrupt;
+
+	return interrupt;
+}
+
+int pci_ep_set_msix(struct udevice *dev, uint func_no, uint interrupts)
+{
+	struct pci_ep_ops *ops = pci_ep_get_ops(dev);
+
+	if (interrupts < 1 || interrupts > 2048)
+		return -EINVAL;
+
+	if (!ops->set_msix)
+		return -ENOSYS;
+
+	return ops->set_msix(dev, func_no, interrupts - 1);
+}
+
+int pci_ep_get_msix(struct udevice *dev, uint func_no)
+{
+	struct pci_ep_ops *ops = pci_ep_get_ops(dev);
+	int interrupt;
+
+	if (!ops->get_msix)
+		return -ENOSYS;
+
+	interrupt = ops->get_msix(dev, func_no);
+
+	if (interrupt < 0)
+		return 0;
+
+	return interrupt + 1;
+}
+
+int pci_ep_raise_irq(struct udevice *dev, uint func_no,
+		     enum pci_ep_irq_type type, uint interrupt_num)
+{
+	struct pci_ep_ops *ops = pci_ep_get_ops(dev);
+
+	if (!ops->raise_irq)
+		return -ENOSYS;
+
+	return ops->raise_irq(dev, func_no, type, interrupt_num);
+}
+
+int pci_ep_start(struct udevice *dev)
+{
+	struct pci_ep_ops *ops = pci_ep_get_ops(dev);
+
+	if (!ops->start)
+		return -ENOSYS;
+
+	return ops->start(dev);
+}
+
+int pci_ep_stop(struct udevice *dev)
+{
+	struct pci_ep_ops *ops = pci_ep_get_ops(dev);
+
+	if (!ops->stop)
+		return -ENOSYS;
+
+	return ops->stop(dev);
+}
+
+UCLASS_DRIVER(pci_ep) = {
+	.id		= UCLASS_PCI_EP,
+	.name		= "pci_ep",
+	.flags		= DM_UC_FLAG_SEQ_ALIAS,
+};