[v3 5/6] PCI: rcar: Add support for rcar PCIe controller in endpoint mode

From: Lad Prabhakar
Date: Wed Jan 08 2020 - 11:22:27 EST


This patch adds support for rcar PCIe controller to work in endpoint mode.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
---
drivers/pci/controller/Kconfig | 7 +
drivers/pci/controller/Makefile | 1 +
drivers/pci/controller/pcie-rcar-ep.c | 497 ++++++++++++++++++++++++++
drivers/pci/controller/pcie-rcar.h | 6 +
4 files changed, 511 insertions(+)
create mode 100644 drivers/pci/controller/pcie-rcar-ep.c

diff --git a/drivers/pci/controller/Kconfig b/drivers/pci/controller/Kconfig
index b022ac5678f7..69b1c778dad4 100644
--- a/drivers/pci/controller/Kconfig
+++ b/drivers/pci/controller/Kconfig
@@ -61,6 +61,13 @@ config PCIE_RCAR_HOST
help
Say Y here if you want PCIe controller support on R-Car SoCs in host mode.

+config PCIE_RCAR_EP
+ bool "Renesas R-Car PCIe endpoint controller"
+ depends on ARCH_RENESAS || COMPILE_TEST
+ depends on PCI_ENDPOINT
+ help
+ Say Y here if you want PCIe controller support on R-Car SoCs in endpoint mode.
+
config PCI_HOST_COMMON
bool
select PCI_ECAM
diff --git a/drivers/pci/controller/Makefile b/drivers/pci/controller/Makefile
index 69ba1dbf837b..61505b1fc66a 100644
--- a/drivers/pci/controller/Makefile
+++ b/drivers/pci/controller/Makefile
@@ -8,6 +8,7 @@ obj-$(CONFIG_PCI_AARDVARK) += pci-aardvark.o
obj-$(CONFIG_PCI_TEGRA) += pci-tegra.o
obj-$(CONFIG_PCI_RCAR_GEN2) += pci-rcar-gen2.o
obj-$(CONFIG_PCIE_RCAR_HOST) += pcie-rcar.o pcie-rcar-host.o
+obj-$(CONFIG_PCIE_RCAR_EP) += pcie-rcar.o pcie-rcar-ep.o
obj-$(CONFIG_PCI_HOST_COMMON) += pci-host-common.o
obj-$(CONFIG_PCI_HOST_GENERIC) += pci-host-generic.o
obj-$(CONFIG_PCIE_XILINX) += pcie-xilinx.o
diff --git a/drivers/pci/controller/pcie-rcar-ep.c b/drivers/pci/controller/pcie-rcar-ep.c
new file mode 100644
index 000000000000..40cd2aad8c3c
--- /dev/null
+++ b/drivers/pci/controller/pcie-rcar-ep.c
@@ -0,0 +1,497 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PCIe endpoint driver for Renesas R-Car SoCs
+ * Copyright (c) 2020 Renesas Electronics Europe GmbH
+ *
+ * Author: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/of_pci.h>
+#include <linux/of_platform.h>
+#include <linux/pci.h>
+#include <linux/pci-epc.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+
+#include "pcie-rcar.h"
+
+#define MAX_NR_INBOUND_MAPS 6
+#define MAX_NR_OUTBOUND_MAPS 4
+
+/* Structure representing the PCIe interface */
+struct rcar_pcie {
+ phys_addr_t *ob_addr;
+ struct pci_epc_mem_window *ob_window;
+ struct pci_epc *epc;
+ struct device *dev;
+ void __iomem *base;
+ u8 max_functions;
+ unsigned int bar_to_atu[MAX_NR_INBOUND_MAPS];
+ unsigned long *ib_window_map;
+ u32 num_ib_windows;
+ u32 num_ob_windows;
+};
+
+static void rcar_pcie_ep_hw_init(struct rcar_pcie *pcie)
+{
+ u32 val;
+
+ rcar_pci_write_reg(pcie->base, 0, PCIETCTLR);
+
+ /* Set endpoint mode */
+ rcar_pci_write_reg(pcie->base, 0, PCIEMSR);
+
+ /* Initialize default capabilities. */
+ rcar_rmw32(pcie->base, REXPCAP(0), 0xff, PCI_CAP_ID_EXP);
+ rcar_rmw32(pcie->base, REXPCAP(PCI_EXP_FLAGS),
+ PCI_EXP_FLAGS_TYPE, PCI_EXP_TYPE_ENDPOINT << 4);
+ rcar_rmw32(pcie->base, RCONF(PCI_HEADER_TYPE), 0x7f,
+ PCI_HEADER_TYPE_NORMAL);
+
+ /* Write out the physical slot number = 0 */
+ rcar_rmw32(pcie->base, REXPCAP(PCI_EXP_SLTCAP), PCI_EXP_SLTCAP_PSN, 0);
+
+ val = rcar_pci_read_reg(pcie->base, EXPCAP(1));
+ /* device supports fixed 128 bytes MPSS */
+ val &= ~GENMASK(2, 0);
+ /* L1 to L0 transition latency no time limit */
+ val |= GENMASK(11, 9);
+ /* L0s to L0 transistion no time limit */
+ val |= GENMASK(8, 6);
+ rcar_pci_write_reg(pcie->base, val, EXPCAP(1));
+
+ val = rcar_pci_read_reg(pcie->base, EXPCAP(2));
+ /* read requests size 128 bytes */
+ val &= ~GENMASK(14, 12);
+ /* payload size 128 bytes */
+ val &= ~GENMASK(7, 5);
+ /* disable relaxed ordering transaction */
+ val &= ~BIT(4);
+ rcar_pci_write_reg(pcie->base, val, EXPCAP(2));
+
+ val = rcar_pci_read_reg(pcie->base, EXPCAP(4));
+ /* disable ASPM control */
+ val &= ~GENMASK(1, 0);
+ rcar_pci_write_reg(pcie->base, val, EXPCAP(4));
+
+ /* Set target link speed to 5.0 GT/s */
+ rcar_rmw32(pcie->base, EXPCAP(12), PCI_EXP_LNKSTA_CLS,
+ PCI_EXP_LNKSTA_CLS_5_0GB);
+
+ /* Set the completion timer timeout to the maximum 50ms. */
+ rcar_rmw32(pcie->base, TLCTLR + 1, 0x3f, 50);
+
+ /* Terminate list of capabilities (Next Capability Offset=0) */
+ rcar_rmw32(pcie->base, RVCCAP(0), 0xfff00000, 0);
+
+ /* flush modifications */
+ wmb();
+}
+
+static int rcar_pcie_parse_outbound_ranges(struct rcar_pcie *pcie,
+ struct platform_device *pdev)
+{
+ char outbound_name[10];
+ struct resource *res;
+ unsigned int i = 0;
+
+ pcie->num_ob_windows = 0;
+ for (i = 0; i < MAX_NR_OUTBOUND_MAPS; i++) {
+ sprintf(outbound_name, "memory%u", i);
+ res = platform_get_resource_byname(pdev,
+ IORESOURCE_MEM,
+ outbound_name);
+ if (!res) {
+ dev_err(pcie->dev, "missing outbound window %u\n", i);
+ return -EINVAL;
+ }
+ if (!devm_request_mem_region(&pdev->dev, res->start,
+ resource_size(res),
+ outbound_name)) {
+ dev_err(pcie->dev, "Cannot request memory region %s.\n",
+ outbound_name);
+ return -EIO;
+ }
+
+ pcie->ob_window[i].phys_base = res->start;
+ pcie->ob_window[i].size = resource_size(res);
+ /* controller doesn't support multiple allocation
+ * from same window, so set page_size to window size
+ */
+ pcie->ob_window[i].page_size = resource_size(res);
+ }
+ pcie->num_ob_windows = i;
+
+ return 0;
+}
+
+static int rcar_pcie_ep_get_pdata(struct rcar_pcie *pcie,
+ struct platform_device *pdev)
+{
+ struct pci_epc_mem_window *window;
+ struct device *dev = pcie->dev;
+ struct resource res;
+ int err;
+
+ err = of_address_to_resource(dev->of_node, 0, &res);
+ if (err)
+ return err;
+ pcie->base = devm_ioremap_resource(dev, &res);
+ if (IS_ERR(pcie->base))
+ return PTR_ERR(pcie->base);
+
+ pcie->ob_window = devm_kcalloc(dev, MAX_NR_OUTBOUND_MAPS,
+ sizeof(*window), GFP_KERNEL);
+ if (!pcie->ob_window)
+ return -ENOMEM;
+
+ rcar_pcie_parse_outbound_ranges(pcie, pdev);
+
+ err = of_property_read_u8(dev->of_node, "max-functions",
+ &pcie->max_functions);
+ if (err < 0)
+ pcie->max_functions = 1;
+
+ return 0;
+}
+
+static int rcar_pcie_ep_write_header(struct pci_epc *epc, u8 fn,
+ struct pci_epf_header *hdr)
+{
+ struct rcar_pcie *ep = epc_get_drvdata(epc);
+ u32 val;
+
+ if (!fn)
+ val = hdr->vendorid;
+ else
+ val = rcar_pci_read_reg(ep->base, IDSETR0);
+ val |= hdr->deviceid << DEVICE_ID_SHFIT;
+ rcar_pci_write_reg(ep->base, val, IDSETR0);
+
+ val = hdr->revid;
+ val |= hdr->progif_code << 8;
+ val |= hdr->subclass_code << 16;
+ val |= hdr->baseclass_code << 24;
+ rcar_pci_write_reg(ep->base, val, IDSETR1);
+
+ if (!fn)
+ val = hdr->subsys_vendor_id;
+ else
+ val = rcar_pci_read_reg(ep->base, SUBIDSETR);
+ val |= hdr->subsys_id << 16;
+ rcar_pci_write_reg(ep->base, val, SUBIDSETR);
+
+ if (hdr->interrupt_pin > PCI_INTERRUPT_INTA)
+ return -EINVAL;
+ val = rcar_pci_read_reg(ep->base, PCICONF(15));
+ val |= (hdr->interrupt_pin << 8);
+ rcar_pci_write_reg(ep->base, val, PCICONF(15));
+
+ return 0;
+}
+
+static int rcar_pcie_ep_set_bar(struct pci_epc *epc, u8 func_no,
+ struct pci_epf_bar *epf_bar)
+{
+ struct rcar_pcie *ep = epc_get_drvdata(epc);
+ dma_addr_t cpu_addr = epf_bar->phys_addr;
+ int flags = epf_bar->flags | LAR_ENABLE | LAM_64BIT;
+ enum pci_barno bar = epf_bar->barno;
+ u64 size = 1ULL << fls64(epf_bar->size - 1);
+ u32 mask;
+ int idx;
+ int err;
+
+ idx = find_first_zero_bit(ep->ib_window_map, ep->num_ib_windows);
+ if (idx >= ep->num_ib_windows) {
+ dev_err(ep->dev, "no free inbound window\n");
+ return -EINVAL;
+ }
+
+ if ((flags & PCI_BASE_ADDRESS_SPACE) == PCI_BASE_ADDRESS_SPACE_IO)
+ flags |= IO_SPACE;
+
+ ep->bar_to_atu[bar] = idx;
+ /* use 64 bit bars */
+ set_bit(idx, ep->ib_window_map);
+ set_bit(idx + 1, ep->ib_window_map);
+
+ if (cpu_addr > 0) {
+ unsigned long nr_zeros = __ffs64(cpu_addr);
+ u64 alignment = 1ULL << nr_zeros;
+
+ size = min(size, alignment);
+ } else {
+ size = size;
+ }
+
+ size = min(size, 1ULL << 32);
+
+ mask = roundup_pow_of_two(size) - 1;
+ mask &= ~0xf;
+
+ rcar_pcie_set_inbound(ep->base, cpu_addr,
+ 0x0, mask | flags, idx, false);
+
+ err = rcar_pcie_wait_for_phyrdy(ep->base);
+ if (err) {
+ dev_err(ep->dev, "phy not ready\n");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static void rcar_pcie_ep_clear_bar(struct pci_epc *epc, u8 fn,
+ struct pci_epf_bar *epf_bar)
+{
+ struct rcar_pcie *ep = epc_get_drvdata(epc);
+ enum pci_barno bar = epf_bar->barno;
+ u32 atu_index = ep->bar_to_atu[bar];
+
+ rcar_pcie_set_inbound(ep->base, 0x0, 0x0, 0x0, bar, false);
+
+ clear_bit(atu_index, ep->ib_window_map);
+ clear_bit(atu_index + 1, ep->ib_window_map);
+}
+
+static int rcar_pcie_ep_map_addr(struct pci_epc *epc, u8 fn,
+ phys_addr_t addr, int window,
+ u64 pci_addr, size_t size)
+{
+ struct rcar_pcie *ep = epc_get_drvdata(epc);
+ struct resource res;
+ int err;
+
+ /* check if we have a link. */
+ err = rcar_pcie_wait_for_dl(ep->base);
+ if (err) {
+ dev_err(ep->dev, "link not up\n");
+ memset(&res, 0x0, sizeof(res));
+ rcar_pcie_set_outbound(window, ep->base, &res, false);
+ return err;
+ }
+
+ if (window >= ep->num_ob_windows) {
+ dev_err(ep->dev, "no free outbound window\n");
+ return -EINVAL;
+ }
+
+ memset(&res, 0x0, sizeof(res));
+ res.start = pci_addr;
+ res.end = pci_addr + size - 1;
+ res.flags = IORESOURCE_MEM;
+
+ rcar_pcie_set_outbound(window, ep->base, &res, false);
+
+ ep->ob_addr[window] = addr;
+
+ return 0;
+}
+
+static void rcar_pcie_ep_unmap_addr(struct pci_epc *epc, u8 fn,
+ phys_addr_t addr)
+{
+ struct rcar_pcie *ep = epc_get_drvdata(epc);
+ struct resource res;
+ int idx;
+
+ for (idx = 0; idx < ep->num_ob_windows; idx++)
+ if (ep->ob_addr[idx] == addr)
+ break;
+
+ if (idx >= ep->num_ob_windows)
+ return;
+
+ memset(&res, 0x0, sizeof(res));
+ rcar_pcie_set_outbound(idx, ep->base, &res, false);
+
+ ep->ob_addr[idx] = 0;
+}
+
+static int rcar_pcie_ep_assert_intx(struct rcar_pcie *ep, u8 fn, u8 intx)
+{
+ u32 val;
+
+ val = rcar_pci_read_reg(ep->base, PCIEMSITXR);
+ if ((val & PCI_MSI_FLAGS_ENABLE)) {
+ dev_err(ep->dev, "MSI is enabled, cannot assert INTx\n");
+ return -EINVAL;
+ }
+
+ val = rcar_pci_read_reg(ep->base, PCICONF(1));
+ if ((val & INTDIS_SHIFT)) {
+ dev_err(ep->dev, "INTx message transmission is disabled\n");
+ return -EINVAL;
+ }
+
+ val = rcar_pci_read_reg(ep->base, PCIEINTXR);
+ if ((val & ASTINTX_SHIFT)) {
+ dev_err(ep->dev, "INTx is already asserted\n");
+ return -EINVAL;
+ }
+
+ val |= ASTINTX_SHIFT;
+ rcar_pci_write_reg(ep->base, val, PCIEINTXR);
+ mdelay(1);
+ val = rcar_pci_read_reg(ep->base, PCIEINTXR);
+ val &= ~ASTINTX_SHIFT;
+ rcar_pci_write_reg(ep->base, val, PCIEINTXR);
+
+ return 0;
+}
+
+static int rcar_pcie_ep_raise_irq(struct pci_epc *epc, u8 fn,
+ enum pci_epc_irq_type type,
+ u16 interrupt_num)
+{
+ struct rcar_pcie *ep = epc_get_drvdata(epc);
+
+ switch (type) {
+ case PCI_EPC_IRQ_LEGACY:
+ return rcar_pcie_ep_assert_intx(ep, fn, 0);
+ default:
+ return -EINVAL;
+ }
+}
+
+static int rcar_pcie_ep_start(struct pci_epc *epc)
+{
+ struct rcar_pcie *ep = epc_get_drvdata(epc);
+
+ rcar_pci_write_reg(ep->base, CFINIT, PCIETCTLR);
+
+ return 0;
+}
+
+static void rcar_pcie_ep_stop(struct pci_epc *epc)
+{
+ struct rcar_pcie *ep = epc_get_drvdata(epc);
+
+ rcar_pci_write_reg(ep->base, 0, PCIETCTLR);
+}
+
+static const struct pci_epc_features rcar_pcie_epc_features = {
+ .linkup_notifier = false,
+ .msi_capable = false,
+ .msix_capable = false,
+ /* use 64-bit bars so mark bar1/3/5 as reserved */
+ .reserved_bar = 1 << BAR_1 | 1 << BAR_3 | 1 << BAR_5,
+ .bar_fixed_64bit = (1 << BAR_0) | (1 << BAR_2) | (1 << BAR_4),
+ .bar_fixed_size[0] = 128,
+ .bar_fixed_size[2] = 256,
+ .bar_fixed_size[4] = 256,
+};
+
+static const struct pci_epc_features*
+rcar_pcie_ep_get_features(struct pci_epc *epc, u8 func_no)
+{
+ return &rcar_pcie_epc_features;
+}
+
+static const struct pci_epc_ops rcar_pcie_epc_ops = {
+ .write_header = rcar_pcie_ep_write_header,
+ .set_bar = rcar_pcie_ep_set_bar,
+ .clear_bar = rcar_pcie_ep_clear_bar,
+ .map_addr = rcar_pcie_ep_map_addr,
+ .unmap_addr = rcar_pcie_ep_unmap_addr,
+ .raise_irq = rcar_pcie_ep_raise_irq,
+ .start = rcar_pcie_ep_start,
+ .stop = rcar_pcie_ep_stop,
+ .get_features = rcar_pcie_ep_get_features,
+};
+
+static const struct of_device_id rcar_pcie_ep_of_match[] = {
+ {
+ .compatible = "renesas,rcar-gen3-pcie-ep"
+ },
+ {},
+};
+
+static int rcar_pcie_ep_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct rcar_pcie *pcie;
+ struct pci_epc *epc;
+ int err;
+
+ pcie = devm_kzalloc(dev, sizeof(*pcie), GFP_KERNEL);
+ if (!pcie)
+ return -ENOMEM;
+
+ pcie->dev = dev;
+
+ pm_runtime_enable(pcie->dev);
+ err = pm_runtime_get_sync(pcie->dev);
+ if (err < 0) {
+ dev_err(pcie->dev, "pm_runtime_get_sync failed\n");
+ goto err_pm_disable;
+ }
+
+ err = rcar_pcie_ep_get_pdata(pcie, pdev);
+ if (err < 0) {
+ dev_err(dev, "failed to request resources: %d\n", err);
+ goto err_pm_put;
+ }
+
+ pcie->num_ib_windows = MAX_NR_INBOUND_MAPS;
+ pcie->ib_window_map =
+ devm_kcalloc(dev, BITS_TO_LONGS(pcie->num_ib_windows),
+ sizeof(long), GFP_KERNEL);
+ if (!pcie->ib_window_map) {
+ err = -ENOMEM;
+ dev_err(dev, "failed to allocate memory for inbound map\n");
+ goto err_pm_put;
+ }
+
+ pcie->ob_addr = devm_kcalloc(dev, pcie->num_ob_windows,
+ sizeof(*pcie->ob_addr), GFP_KERNEL);
+ if (!pcie->ob_addr) {
+ err = -ENOMEM;
+ dev_err(dev, "failed to allocate memory for outbound memory pointers\n");
+ goto err_pm_put;
+ }
+
+ epc = devm_pci_epc_create(dev, &rcar_pcie_epc_ops);
+ if (IS_ERR(epc)) {
+ dev_err(dev, "failed to create epc device\n");
+ err = PTR_ERR(epc);
+ goto err_pm_put;
+ }
+
+ epc->max_functions = pcie->max_functions;
+ pcie->epc = epc;
+ epc_set_drvdata(epc, pcie);
+
+ err = pci_epc_mem_init(epc, pcie->ob_window, pcie->num_ob_windows);
+ if (err < 0) {
+ dev_err(dev, "failed to initialize the epc memory space\n");
+ goto err_pm_put;
+ }
+
+ rcar_pcie_ep_hw_init(pcie);
+
+ return 0;
+
+err_pm_put:
+ pm_runtime_put(dev);
+
+err_pm_disable:
+ pm_runtime_disable(dev);
+
+ return err;
+}
+
+static struct platform_driver rcar_pcie_ep_driver = {
+ .driver = {
+ .name = "rcar-pcie-ep",
+ .of_match_table = rcar_pcie_ep_of_match,
+ .suppress_bind_attrs = true,
+ },
+ .probe = rcar_pcie_ep_probe,
+};
+builtin_platform_driver(rcar_pcie_ep_driver);
diff --git a/drivers/pci/controller/pcie-rcar.h b/drivers/pci/controller/pcie-rcar.h
index cbb21d37b539..e8d15163a39d 100644
--- a/drivers/pci/controller/pcie-rcar.h
+++ b/drivers/pci/controller/pcie-rcar.h
@@ -60,7 +60,10 @@
#define VCCAP(x) (0x010100 + ((x) * 0x4))

/* link layer */
+#define IDSETR0 0x011000
+#define DEVICE_ID_SHFIT 16
#define IDSETR1 0x011004
+#define SUBIDSETR 0x011024
#define TLCTLR 0x011048
#define MACSR 0x011054
#define SPCHGFIN BIT(4)
@@ -101,6 +104,9 @@
#define REXPCAP(x) (EXPCAP(0) + (x))
#define RVCCAP(x) (VCCAP(0) + (x))

+#define INTDIS_SHIFT BIT(10)
+#define ASTINTX_SHIFT BIT(16)
+
#define PCIE_CONF_BUS(b) (((b) & 0xff) << 24)
#define PCIE_CONF_DEV(d) (((d) & 0x1f) << 19)
#define PCIE_CONF_FUNC(f) (((f) & 0x7) << 16)
--
2.20.1