PCI: dwc: designware: Add EP mode support

Add endpoint mode support to designware driver. This uses the EP Core layer
introduced recently to add endpoint mode support.  *Any* function driver
can now use this designware device in order to achieve the EP
functionality.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

drivers/pci/dwc/Kconfig

@@ -9,6 +9,11 @@ config PCIE_DW_HOST
 	depends on PCI_MSI_IRQ_DOMAIN
         select PCIE_DW
 
+config PCIE_DW_EP
+	bool
+	depends on PCI_ENDPOINT
+	select PCIE_DW
+
 config PCI_DRA7XX
 	bool "TI DRA7xx PCIe controller"
 	depends on PCI

drivers/pci/dwc/Makefile

@@ -1,5 +1,6 @@
 obj-$(CONFIG_PCIE_DW) += pcie-designware.o
 obj-$(CONFIG_PCIE_DW_HOST) += pcie-designware-host.o
+obj-$(CONFIG_PCIE_DW_EP) += pcie-designware-ep.o
 obj-$(CONFIG_PCIE_DW_PLAT) += pcie-designware-plat.o
 obj-$(CONFIG_PCI_DRA7XX) += pci-dra7xx.o
 obj-$(CONFIG_PCI_EXYNOS) += pci-exynos.o

drivers/pci/dwc/pcie-designware-ep.c

@@ -0,0 +1,342 @@
+/**
+ * Synopsys Designware PCIe Endpoint controller driver
+ *
+ * Copyright (C) 2017 Texas Instruments
+ * Author: Kishon Vijay Abraham I <kishon@ti.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 of
+ * the License 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/of.h>
+
+#include "pcie-designware.h"
+#include <linux/pci-epc.h>
+#include <linux/pci-epf.h>
+
+void dw_pcie_ep_linkup(struct dw_pcie_ep *ep)
+{
+	struct pci_epc *epc = ep->epc;
+
+	pci_epc_linkup(epc);
+}
+
+static void dw_pcie_ep_reset_bar(struct dw_pcie *pci, enum pci_barno bar)
+{
+	u32 reg;
+
+	reg = PCI_BASE_ADDRESS_0 + (4 * bar);
+	dw_pcie_writel_dbi2(pci, reg, 0x0);
+	dw_pcie_writel_dbi(pci, reg, 0x0);
+}
+
+static int dw_pcie_ep_write_header(struct pci_epc *epc,
+				   struct pci_epf_header *hdr)
+{
+	struct dw_pcie_ep *ep = epc_get_drvdata(epc);
+	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
+
+	dw_pcie_writew_dbi(pci, PCI_VENDOR_ID, hdr->vendorid);
+	dw_pcie_writew_dbi(pci, PCI_DEVICE_ID, hdr->deviceid);
+	dw_pcie_writeb_dbi(pci, PCI_REVISION_ID, hdr->revid);
+	dw_pcie_writeb_dbi(pci, PCI_CLASS_PROG, hdr->progif_code);
+	dw_pcie_writew_dbi(pci, PCI_CLASS_DEVICE,
+			   hdr->subclass_code | hdr->baseclass_code << 8);
+	dw_pcie_writeb_dbi(pci, PCI_CACHE_LINE_SIZE,
+			   hdr->cache_line_size);
+	dw_pcie_writew_dbi(pci, PCI_SUBSYSTEM_VENDOR_ID,
+			   hdr->subsys_vendor_id);
+	dw_pcie_writew_dbi(pci, PCI_SUBSYSTEM_ID, hdr->subsys_id);
+	dw_pcie_writeb_dbi(pci, PCI_INTERRUPT_PIN,
+			   hdr->interrupt_pin);
+
+	return 0;
+}
+
+static int dw_pcie_ep_inbound_atu(struct dw_pcie_ep *ep, enum pci_barno bar,
+				  dma_addr_t cpu_addr,
+				  enum dw_pcie_as_type as_type)
+{
+	int ret;
+	u32 free_win;
+	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
+
+	free_win = find_first_zero_bit(&ep->ib_window_map,
+				       sizeof(ep->ib_window_map));
+	if (free_win >= ep->num_ib_windows) {
+		dev_err(pci->dev, "no free inbound window\n");
+		return -EINVAL;
+	}
+
+	ret = dw_pcie_prog_inbound_atu(pci, free_win, bar, cpu_addr,
+				       as_type);
+	if (ret < 0) {
+		dev_err(pci->dev, "Failed to program IB window\n");
+		return ret;
+	}
+
+	ep->bar_to_atu[bar] = free_win;
+	set_bit(free_win, &ep->ib_window_map);
+
+	return 0;
+}
+
+static int dw_pcie_ep_outbound_atu(struct dw_pcie_ep *ep, phys_addr_t phys_addr,
+				   u64 pci_addr, size_t size)
+{
+	u32 free_win;
+	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
+
+	free_win = find_first_zero_bit(&ep->ob_window_map,
+				       sizeof(ep->ob_window_map));
+	if (free_win >= ep->num_ob_windows) {
+		dev_err(pci->dev, "no free outbound window\n");
+		return -EINVAL;
+	}
+
+	dw_pcie_prog_outbound_atu(pci, free_win, PCIE_ATU_TYPE_MEM,
+				  phys_addr, pci_addr, size);
+
+	set_bit(free_win, &ep->ob_window_map);
+	ep->outbound_addr[free_win] = phys_addr;
+
+	return 0;
+}
+
+static void dw_pcie_ep_clear_bar(struct pci_epc *epc, enum pci_barno bar)
+{
+	struct dw_pcie_ep *ep = epc_get_drvdata(epc);
+	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
+	u32 atu_index = ep->bar_to_atu[bar];
+
+	dw_pcie_ep_reset_bar(pci, bar);
+
+	dw_pcie_disable_atu(pci, atu_index, DW_PCIE_REGION_INBOUND);
+	clear_bit(atu_index, &ep->ib_window_map);
+}
+
+static int dw_pcie_ep_set_bar(struct pci_epc *epc, enum pci_barno bar,
+			      dma_addr_t bar_phys, size_t size, int flags)
+{
+	int ret;
+	struct dw_pcie_ep *ep = epc_get_drvdata(epc);
+	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
+	enum dw_pcie_as_type as_type;
+	u32 reg = PCI_BASE_ADDRESS_0 + (4 * bar);
+
+	if (!(flags & PCI_BASE_ADDRESS_SPACE))
+		as_type = DW_PCIE_AS_MEM;
+	else
+		as_type = DW_PCIE_AS_IO;
+
+	ret = dw_pcie_ep_inbound_atu(ep, bar, bar_phys, as_type);
+	if (ret)
+		return ret;
+
+	dw_pcie_writel_dbi2(pci, reg, size - 1);
+	dw_pcie_writel_dbi(pci, reg, flags);
+
+	return 0;
+}
+
+static int dw_pcie_find_index(struct dw_pcie_ep *ep, phys_addr_t addr,
+			      u32 *atu_index)
+{
+	u32 index;
+
+	for (index = 0; index < ep->num_ob_windows; index++) {
+		if (ep->outbound_addr[index] != addr)
+			continue;
+		*atu_index = index;
+		return 0;
+	}
+
+	return -EINVAL;
+}
+
+static void dw_pcie_ep_unmap_addr(struct pci_epc *epc, phys_addr_t addr)
+{
+	int ret;
+	u32 atu_index;
+	struct dw_pcie_ep *ep = epc_get_drvdata(epc);
+	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
+
+	ret = dw_pcie_find_index(ep, addr, &atu_index);
+	if (ret < 0)
+		return;
+
+	dw_pcie_disable_atu(pci, atu_index, DW_PCIE_REGION_OUTBOUND);
+	clear_bit(atu_index, &ep->ob_window_map);
+}
+
+static int dw_pcie_ep_map_addr(struct pci_epc *epc, phys_addr_t addr,
+			       u64 pci_addr, size_t size)
+{
+	int ret;
+	struct dw_pcie_ep *ep = epc_get_drvdata(epc);
+	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
+
+	ret = dw_pcie_ep_outbound_atu(ep, addr, pci_addr, size);
+	if (ret) {
+		dev_err(pci->dev, "failed to enable address\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static int dw_pcie_ep_get_msi(struct pci_epc *epc)
+{
+	int val;
+	u32 lower_addr;
+	u32 upper_addr;
+	struct dw_pcie_ep *ep = epc_get_drvdata(epc);
+	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
+
+	val = dw_pcie_readb_dbi(pci, MSI_MESSAGE_CONTROL);
+	val = (val & MSI_CAP_MME_MASK) >> MSI_CAP_MME_SHIFT;
+
+	lower_addr = dw_pcie_readl_dbi(pci, MSI_MESSAGE_ADDR_L32);
+	upper_addr = dw_pcie_readl_dbi(pci, MSI_MESSAGE_ADDR_U32);
+
+	if (!(lower_addr || upper_addr))
+		return -EINVAL;
+
+	return val;
+}
+
+static int dw_pcie_ep_set_msi(struct pci_epc *epc, u8 encode_int)
+{
+	int val;
+	struct dw_pcie_ep *ep = epc_get_drvdata(epc);
+	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
+
+	val = (encode_int << MSI_CAP_MMC_SHIFT);
+	dw_pcie_writew_dbi(pci, MSI_MESSAGE_CONTROL, val);
+
+	return 0;
+}
+
+static int dw_pcie_ep_raise_irq(struct pci_epc *epc,
+				enum pci_epc_irq_type type, u8 interrupt_num)
+{
+	struct dw_pcie_ep *ep = epc_get_drvdata(epc);
+
+	if (!ep->ops->raise_irq)
+		return -EINVAL;
+
+	return ep->ops->raise_irq(ep, type, interrupt_num);
+}
+
+static void dw_pcie_ep_stop(struct pci_epc *epc)
+{
+	struct dw_pcie_ep *ep = epc_get_drvdata(epc);
+	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
+
+	if (!pci->ops->stop_link)
+		return;
+
+	pci->ops->stop_link(pci);
+}
+
+static int dw_pcie_ep_start(struct pci_epc *epc)
+{
+	struct dw_pcie_ep *ep = epc_get_drvdata(epc);
+	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
+
+	if (!pci->ops->start_link)
+		return -EINVAL;
+
+	return pci->ops->start_link(pci);
+}
+
+static const struct pci_epc_ops epc_ops = {
+	.write_header		= dw_pcie_ep_write_header,
+	.set_bar		= dw_pcie_ep_set_bar,
+	.clear_bar		= dw_pcie_ep_clear_bar,
+	.map_addr		= dw_pcie_ep_map_addr,
+	.unmap_addr		= dw_pcie_ep_unmap_addr,
+	.set_msi		= dw_pcie_ep_set_msi,
+	.get_msi		= dw_pcie_ep_get_msi,
+	.raise_irq		= dw_pcie_ep_raise_irq,
+	.start			= dw_pcie_ep_start,
+	.stop			= dw_pcie_ep_stop,
+};
+
+void dw_pcie_ep_exit(struct dw_pcie_ep *ep)
+{
+	struct pci_epc *epc = ep->epc;
+
+	pci_epc_mem_exit(epc);
+}
+
+int dw_pcie_ep_init(struct dw_pcie_ep *ep)
+{
+	int ret;
+	void *addr;
+	enum pci_barno bar;
+	struct pci_epc *epc;
+	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
+	struct device *dev = pci->dev;
+	struct device_node *np = dev->of_node;
+
+	if (!pci->dbi_base || !pci->dbi_base2) {
+		dev_err(dev, "dbi_base/deb_base2 is not populated\n");
+		return -EINVAL;
+	}
+
+	ret = of_property_read_u32(np, "num-ib-windows", &ep->num_ib_windows);
+	if (ret < 0) {
+		dev_err(dev, "unable to read *num-ib-windows* property\n");
+		return ret;
+	}
+
+	ret = of_property_read_u32(np, "num-ob-windows", &ep->num_ob_windows);
+	if (ret < 0) {
+		dev_err(dev, "unable to read *num-ob-windows* property\n");
+		return ret;
+	}
+
+	addr = devm_kzalloc(dev, sizeof(phys_addr_t) * ep->num_ob_windows,
+			    GFP_KERNEL);
+	if (!addr)
+		return -ENOMEM;
+	ep->outbound_addr = addr;
+
+	for (bar = BAR_0; bar <= BAR_5; bar++)
+		dw_pcie_ep_reset_bar(pci, bar);
+
+	if (ep->ops->ep_init)
+		ep->ops->ep_init(ep);
+
+	epc = devm_pci_epc_create(dev, &epc_ops);
+	if (IS_ERR(epc)) {
+		dev_err(dev, "failed to create epc device\n");
+		return PTR_ERR(epc);
+	}
+
+	ret = of_property_read_u8(np, "max-functions", &epc->max_functions);
+	if (ret < 0)
+		epc->max_functions = 1;
+
+	ret = pci_epc_mem_init(epc, ep->phys_base, ep->addr_size);
+	if (ret < 0) {
+		dev_err(dev, "Failed to initialize address space\n");
+		return ret;
+	}
+
+	ep->epc = epc;
+	epc_set_drvdata(epc, ep);
+	dw_pcie_setup(pci);
+
+	return 0;
+}