[PATCH v2 08/22] PCI: dwc: designware: Add EP mode support

[Kishon Vijay Abraham I <kishon@ti.com>]

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>
---
 drivers/pci/dwc/Kconfig              |    5 +
 drivers/pci/dwc/Makefile             |    1 +
 drivers/pci/dwc/pcie-designware-ep.c |  342 ++++++++++++++++++++++++++++++++++
 drivers/pci/dwc/pcie-designware.c    |   51 +++++
 drivers/pci/dwc/pcie-designware.h    |   72 +++++++
 5 files changed, 471 insertions(+)
 create mode 100644 drivers/pci/dwc/pcie-designware-ep.c

diff --git a/drivers/pci/dwc/Kconfig b/drivers/pci/dwc/Kconfig
index dfb8a69..00335c7 100644
--- a/drivers/pci/dwc/Kconfig
+++ b/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
diff --git a/drivers/pci/dwc/Makefile b/drivers/pci/dwc/Makefile
index a2df13c..b38425d 100644
--- a/drivers/pci/dwc/Makefile
+++ b/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
diff --git a/drivers/pci/dwc/pcie-designware-ep.c b/drivers/pci/dwc/pcie-designware-ep.c
new file mode 100644
index 0000000..e465c5e
--- /dev/null
+++ b/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;
+	struct pci_epf *epf;
+
+	list_for_each_entry(epf, &epc->pci_epf, list)
+		pci_epf_linkup(epf);
+}
+
+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_write_dbi(pci, pci->dbi_base2, reg, 0x4, 0x0);
+	dw_pcie_write_dbi(pci, pci->dbi_base, reg, 0x4, 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);
+	void __iomem *base = pci->dbi_base;
+
+	dw_pcie_write_dbi(pci, base, PCI_VENDOR_ID, 0x2, hdr->vendorid);
+	dw_pcie_write_dbi(pci, base, PCI_DEVICE_ID, 0x2, hdr->deviceid);
+	dw_pcie_write_dbi(pci, base, PCI_REVISION_ID, 0x1, hdr->revid);
+	dw_pcie_write_dbi(pci, base, PCI_CLASS_PROG, 0x1, hdr->progif_code);
+	dw_pcie_write_dbi(pci, base, PCI_CLASS_DEVICE, 0x2,
+			  hdr->subclass_code | hdr->baseclass_code << 8);
+	dw_pcie_write_dbi(pci, base, PCI_CACHE_LINE_SIZE, 0x1,
+			  hdr->cache_line_size);
+	dw_pcie_write_dbi(pci, base, PCI_SUBSYSTEM_VENDOR_ID, 0x2,
+			  hdr->subsys_vendor_id);
+	dw_pcie_write_dbi(pci, base, PCI_SUBSYSTEM_ID, 0x2, hdr->subsys_id);
+	dw_pcie_write_dbi(pci, base, PCI_INTERRUPT_PIN, 0x1,
+			  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_write_dbi(pci, pci->dbi_base2, reg, 0x4, size - 1);
+	dw_pcie_write_dbi(pci, pci->dbi_base, reg, 0x4, 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_read_dbi(pci, pci->dbi_base, MSI_MESSAGE_CONTROL, 0x2);
+	val = (val & MSI_CAP_MME_MASK) >> MSI_CAP_MME_SHIFT;
+
+	lower_addr = dw_pcie_read_dbi(pci, pci->dbi_base, MSI_MESSAGE_ADDR_L32,
+				      0x4);
+	upper_addr = dw_pcie_read_dbi(pci, pci->dbi_base, MSI_MESSAGE_ADDR_U32,
+				      0x4);
+
+	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_write_dbi(pci, pci->dbi_base, MSI_MESSAGE_CONTROL, 0x2, 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;
+
+	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;
+}
diff --git a/drivers/pci/dwc/pcie-designware.c b/drivers/pci/dwc/pcie-designware.c
index 686945d..49b28c8 100644
--- a/drivers/pci/dwc/pcie-designware.c
+++ b/drivers/pci/dwc/pcie-designware.c
@@ -173,6 +173,57 @@ void dw_pcie_prog_outbound_atu(struct dw_pcie *pci, int index, int type,
 	dev_err(pci->dev, "iATU is not being enabled\n");
 }
 
+int dw_pcie_prog_inbound_atu(struct dw_pcie *pci, int index, int bar,
+			     u64 cpu_addr, enum dw_pcie_as_type as_type)
+{
+	int type;
+	void __iomem *base = pci->dbi_base;
+
+	dw_pcie_write_dbi(pci, base, PCIE_ATU_VIEWPORT, 0x4,
+			  PCIE_ATU_REGION_INBOUND | index);
+	dw_pcie_write_dbi(pci, base, PCIE_ATU_LOWER_TARGET, 0x4,
+			  lower_32_bits(cpu_addr));
+	dw_pcie_write_dbi(pci, base, PCIE_ATU_UPPER_TARGET, 0x4,
+			  upper_32_bits(cpu_addr));
+
+	switch (as_type) {
+	case DW_PCIE_AS_MEM:
+		type = PCIE_ATU_TYPE_MEM;
+		break;
+	case DW_PCIE_AS_IO:
+		type = PCIE_ATU_TYPE_IO;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	dw_pcie_write_dbi(pci, base, PCIE_ATU_CR1, 0x4, type);
+	dw_pcie_write_dbi(pci, base, PCIE_ATU_CR2, 0x4, PCIE_ATU_ENABLE |
+			  PCIE_ATU_BAR_MODE_ENABLE | (bar << 8));
+	return 0;
+}
+
+void dw_pcie_disable_atu(struct dw_pcie *pci, int index,
+			 enum dw_pcie_region_type type)
+{
+	int region;
+	void __iomem *base = pci->dbi_base;
+
+	switch (type) {
+	case DW_PCIE_REGION_INBOUND:
+		region = PCIE_ATU_REGION_INBOUND;
+		break;
+	case DW_PCIE_REGION_OUTBOUND:
+		region = PCIE_ATU_REGION_OUTBOUND;
+		break;
+	default:
+		return;
+	}
+
+	dw_pcie_write_dbi(pci, base, PCIE_ATU_VIEWPORT, 0x4, region | index);
+	dw_pcie_write_dbi(pci, base, PCIE_ATU_CR2, 0x4, ~PCIE_ATU_ENABLE);
+}
+
 int dw_pcie_wait_for_link(struct dw_pcie *pci)
 {
 	int retries;
diff --git a/drivers/pci/dwc/pcie-designware.h b/drivers/pci/dwc/pcie-designware.h
index 0ef6ae7..7476234 100644
--- a/drivers/pci/dwc/pcie-designware.h
+++ b/drivers/pci/dwc/pcie-designware.h
@@ -18,6 +18,9 @@
 #include <linux/msi.h>
 #include <linux/pci.h>
 
+#include <linux/pci-epc.h>
+#include <linux/pci-epf.h>
+
 /* Parameters for the waiting for link up routine */
 #define LINK_WAIT_MAX_RETRIES		10
 #define LINK_WAIT_USLEEP_MIN		90000
@@ -89,6 +92,13 @@
 #define PCIE_GET_ATU_OUTB_UNR_REG_OFFSET(region)	\
 			((0x3 << 20) | ((region) << 9))
 
+#define MSI_MESSAGE_CONTROL		0x52
+#define MSI_CAP_MMC_SHIFT		1
+#define MSI_CAP_MME_SHIFT		4
+#define MSI_CAP_MME_MASK		(7 << MSI_CAP_MME_SHIFT)
+#define MSI_MESSAGE_ADDR_L32		0x54
+#define MSI_MESSAGE_ADDR_U32		0x58
+
 /*
  * Maximum number of MSI IRQs can be 256 per controller. But keep
  * it 32 as of now. Probably we will never need more than 32. If needed,
@@ -99,6 +109,13 @@
 
 struct pcie_port;
 struct dw_pcie;
+struct dw_pcie_ep;
+
+enum dw_pcie_region_type {
+	DW_PCIE_REGION_UNKNOWN,
+	DW_PCIE_REGION_INBOUND,
+	DW_PCIE_REGION_OUTBOUND,
+};
 
 struct dw_pcie_host_ops {
 	int (*rd_own_conf)(struct pcie_port *pp, int where, int size, u32 *val);
@@ -142,6 +159,31 @@ struct pcie_port {
 	DECLARE_BITMAP(msi_irq_in_use, MAX_MSI_IRQS);
 };
 
+enum dw_pcie_as_type {
+	DW_PCIE_AS_UNKNOWN,
+	DW_PCIE_AS_MEM,
+	DW_PCIE_AS_IO,
+};
+
+struct dw_pcie_ep_ops {
+	void	(*ep_init)(struct dw_pcie_ep *ep);
+	int	(*raise_irq)(struct dw_pcie_ep *ep, enum pci_epc_irq_type type,
+			     u8 interrupt_num);
+};
+
+struct dw_pcie_ep {
+	struct pci_epc		*epc;
+	struct dw_pcie_ep_ops	*ops;
+	phys_addr_t		phys_base;
+	size_t			addr_size;
+	u8			bar_to_atu[6];
+	phys_addr_t		*outbound_addr;
+	unsigned long		ib_window_map;
+	unsigned long		ob_window_map;
+	u32			num_ib_windows;
+	u32			num_ob_windows;
+};
+
 struct dw_pcie_ops {
 	u64	(*cpu_addr_fixup)(u64 cpu_addr);
 	u32	(*read_dbi)(struct dw_pcie *pcie, void __iomem *base, u32 reg,
@@ -149,19 +191,26 @@ struct dw_pcie_ops {
 	void	(*write_dbi)(struct dw_pcie *pcie, void __iomem *base, u32 reg,
 			     int size, u32 val);
 	int	(*link_up)(struct dw_pcie *pcie);
+	int	(*start_link)(struct dw_pcie *pcie);
+	void	(*stop_link)(struct dw_pcie *pcie);
 };
 
 struct dw_pcie {
 	struct device		*dev;
 	void __iomem		*dbi_base;
+	void __iomem		*dbi_base2;
 	u32			num_viewport;
 	u8			iatu_unroll_enabled;
 	struct pcie_port	pp;
+	struct dw_pcie_ep	ep;
 	const struct dw_pcie_ops *ops;
 };
 
 #define to_dw_pcie_from_pp(port) container_of((port), struct dw_pcie, pp)
 
+#define to_dw_pcie_from_ep(endpoint)   \
+		container_of((endpoint), struct dw_pcie, ep)
+
 int dw_pcie_read(void __iomem *addr, int size, u32 *val);
 int dw_pcie_write(void __iomem *addr, int size, u32 val);
 
@@ -174,6 +223,10 @@ void dw_pcie_write_dbi(struct dw_pcie *pci, void __iomem *base, u32 reg,
 void dw_pcie_prog_outbound_atu(struct dw_pcie *pci, int index,
 			       int type, u64 cpu_addr, u64 pci_addr,
 			       u32 size);
+int dw_pcie_prog_inbound_atu(struct dw_pcie *pci, int index, int bar,
+			     u64 cpu_addr, enum dw_pcie_as_type as_type);
+void dw_pcie_disable_atu(struct dw_pcie *pci, int index,
+			 enum dw_pcie_region_type type);
 void dw_pcie_setup(struct dw_pcie *pci);
 
 #ifdef CONFIG_PCIE_DW_HOST
@@ -200,4 +253,23 @@ static inline int dw_pcie_host_init(struct pcie_port *pp)
 	return 0;
 }
 #endif
+
+#ifdef CONFIG_PCIE_DW_EP
+void dw_pcie_ep_linkup(struct dw_pcie_ep *ep);
+int dw_pcie_ep_init(struct dw_pcie_ep *ep);
+void dw_pcie_ep_exit(struct dw_pcie_ep *ep);
+#else
+static inline void dw_pcie_ep_linkup(struct dw_pcie_ep *ep)
+{
+}
+
+static inline int dw_pcie_ep_init(struct dw_pcie_ep *ep)
+{
+	return 0;
+}
+
+static inline void dw_pcie_ep_exit(struct dw_pcie_ep *ep)
+{
+}
+#endif
 #endif /* _PCIE_DESIGNWARE_H */
-- 
1.7.9.5