Renesas SH7751 CPU Internal PCI Controller driver.

Signed-off-by: Yoshinori Sato <ys...@users.sourceforge.jp>
---
 drivers/pci/controller/Kconfig      |   9 +
 drivers/pci/controller/Makefile     |   1 +
 drivers/pci/controller/pci-sh7751.c | 342 ++++++++++++++++++++++++++++
 3 files changed, 352 insertions(+)
 create mode 100644 drivers/pci/controller/pci-sh7751.c

diff --git a/drivers/pci/controller/Kconfig b/drivers/pci/controller/Kconfig
index e534c02ee34f..a2fd917a2e03 100644
--- a/drivers/pci/controller/Kconfig
+++ b/drivers/pci/controller/Kconfig
@@ -353,6 +353,15 @@ config PCIE_XILINX_CPM
          Say 'Y' here if you want kernel support for the
          Xilinx Versal CPM host bridge.
 
+config PCI_SH7751
+       bool "Renesas SH7751 PCI controller"
+       depends on OF
+       depends on CPU_SUBTYPE_SH7751 || CPU_SUBTYPE_SH7751R || COMPILE_TEST
+       select PCI_HOST_COMMON
+       help
+         Say 'Y' here if you want kernel to support the Renesas SH7751 PCI
+         Host Bridge driver.
+
 source "drivers/pci/controller/cadence/Kconfig"
 source "drivers/pci/controller/dwc/Kconfig"
 source "drivers/pci/controller/mobiveil/Kconfig"
diff --git a/drivers/pci/controller/Makefile b/drivers/pci/controller/Makefile
index f2b19e6174af..aa97e5d74e58 100644
--- a/drivers/pci/controller/Makefile
+++ b/drivers/pci/controller/Makefile
@@ -40,6 +40,7 @@ obj-$(CONFIG_PCI_LOONGSON) += pci-loongson.o
 obj-$(CONFIG_PCIE_HISI_ERR) += pcie-hisi-error.o
 obj-$(CONFIG_PCIE_APPLE) += pcie-apple.o
 obj-$(CONFIG_PCIE_MT7621) += pcie-mt7621.o
+obj-$(CONFIG_PCI_SH7751) += pci-sh7751.o
 
 # pcie-hisi.o quirks are needed even without CONFIG_PCIE_DW
 obj-y                          += dwc/
diff --git a/drivers/pci/controller/pci-sh7751.c 
b/drivers/pci/controller/pci-sh7751.c
new file mode 100644
index 000000000000..a5340689f737
--- /dev/null
+++ b/drivers/pci/controller/pci-sh7751.c
@@ -0,0 +1,342 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * SH7751 PCI driver
+ * Copyright (C) 2023 Yoshinori Sato
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/of_pci.h>
+#include <linux/of_platform.h>
+#include <linux/pci-ecam.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/pci.h>
+#include <linux/dma-direct.h>
+#include <asm/addrspace.h>
+
+/* PCICR and PCICLKCR write enable magic key */
+#define PCIC_WE_KEY            (0xa5 << 24)
+
+/* PCIC registers */
+/* 0x0000 - 0x00ff mapped to PCI device configuration space */
+#define PCIC_PCICR             0x100   /* PCI Control Register */
+#define PCIC_PCICR_TRSB                BIT(9)  /* Target Read Single */
+#define PCIC_PCICR_BSWP                BIT(8)  /* Target Byte Swap */
+#define PCIC_PCICR_PLUP                BIT(7)  /* Enable PCI Pullup */
+#define PCIC_PCICR_ARBM                BIT(6)  /* PCI Arbitration Mode */
+#define PCIC_PCICR_MD10                BIT(5)  /* MD10 status */
+#define PCIC_PCICR_MD9         BIT(4)  /* MD9 status */
+#define PCIC_PCICR_SERR                BIT(3)  /* SERR output assert */
+#define PCIC_PCICR_INTA                BIT(2)  /* INTA output assert */
+#define PCIC_PCICR_PRST                BIT(1)  /* PCI Reset Assert */
+#define PCIC_PCICR_CFIN                BIT(0)  /* Central Fun. Init Done */
+
+#define PCIC_PCILSR0           0x104   /* PCI Local Space Register0 */
+#define PCIC_PCILSR1           0x108   /* PCI Local Space Register1 */
+#define PCIC_PCILAR0           0x10c   /* PCI Local Addr Register1 */
+#define PCIC_PCILAR1           0x110   /* PCI Local Addr Register1 */
+#define PCIC_PCIINT            0x114   /* PCI Interrupt Register */
+#define PCIC_PCIINTM           0x118   /* PCI Interrupt Mask */
+#define PCIC_PCIALR            0x11c   /* Error Address Register */
+#define PCIC_PCICLR            0x120   /* Error Command/Data */
+#define PCIC_PCIAINT           0x130   /* Arbiter Interrupt Register */
+#define PCIC_PCIAINTM          0x134   /* Arbiter Int. Mask Register */
+#define PCIC_PCIBMLR           0x138   /* Error Bus Master Register */
+#define PCIC_PCIDMABT          0x140   /* DMA Transfer Arb. Register */
+#define PCIC_PCIPAR            0x1c0   /* PIO Address Register */
+#define PCIC_PCIMBR            0x1c4   /* Memory Base Address */
+#define PCIC_PCIIOBR           0x1c8   /* I/O Base Address Register */
+
+#define PCIC_PCIPINT           0x1cc   /* Power Mgmnt Int. Register */
+#define PCIC_PCIPINT_D3                BIT(1)  /* D3 Pwr Mgmt. Interrupt */
+#define PCIC_PCIPINT_D0                BIT(0)  /* D0 Pwr Mgmt. Interrupt */
+
+#define PCIC_PCIPINTM          0x1d0   /* Power Mgmnt Mask Register */
+#define PCIC_PCICLKR           0x1d4   /* Clock Ctrl. Register */
+#define PCIC_PCIBCR1           0x1e0   /* Memory BCR1 Register */
+#define PCIC_PCIBCR2           0x1e4   /* Memory BCR2 Register */
+#define PCIC_PCIWCR1           0x1e8   /* Wait Control 1 Register */
+#define PCIC_PCIWCR2           0x1ec   /* Wait Control 2 Register */
+#define PCIC_PCIWCR3           0x1f0   /* Wait Control 3 Register */
+#define PCIC_PCIMCR            0x1f4   /* Memory Control Register */
+#define PCIC_PCIBCR3           0x1f8   /* Memory BCR3 Register */
+#define PCIC_PCIPDR            0x220   /* Port IO Data Register */
+
+/* PCI IDs */
+/* Hitachi is the company that led to Renesas. */
+/* The SH7751 was designed by Hitachi, so it has a Hitachi ID. */
+#define PCI_VENDOR_ID_HITACHI  0x1054
+#define PCI_DEVICE_ID_SH7751   0x3505
+#define PCI_DEVICE_ID_SH7751R  0x350e
+
+/* BSC registers */
+/* Copy BSC setting to PCI BSC */
+#define BSC_BCR1               0x0000
+#define BSC_BCR1_SLAVE         BIT(30)
+#define BSC_BCR1_BRQEN         BIT(19)
+#define BSC_BCR2               0x0004
+#define BSC_BCR3               0x0050
+#define BSC_WCR1               0x0008
+#define BSC_WCR2               0x000c
+#define BSC_WCR3               0x0010
+#define BSC_MCR                        0x0014
+#define BSC_MCR_MRSET          BIT(30)
+#define BSC_MCR_RFSH           BIT(2)
+
+/* PCIC access wrapper */
+#define pcic_writel(val, base, reg)    writel(val, base + (reg))
+#define pcic_readl(base, reg)          readl(base + (reg))
+
+/*
+ * We need to avoid collisions with `mirrored' VGA ports
+ * and other strange ISA hardware, so we always want the
+ * addresses to be allocated in the 0x000-0x0ff region
+ * modulo 0x400.
+ */
+#define IO_REGION_BASE 0x1000
+resource_size_t pcibios_align_resource(void *data, const struct resource *res,
+                               resource_size_t size, resource_size_t align)
+{
+       resource_size_t start = res->start;
+
+       if (res->flags & IORESOURCE_IO) {
+               if (start < PCIBIOS_MIN_IO + IO_REGION_BASE)
+                       start = PCIBIOS_MIN_IO + IO_REGION_BASE;
+
+               /*
+                * Put everything into 0x00-0xff region modulo 0x400.
+                */
+               if (start & 0x300)
+                       start = (start + 0x3ff) & ~0x3ff;
+       }
+
+       return start;
+}
+
+static int setup_pci_bsc(struct device *dev, void __iomem *pcic,
+                        void __iomem *bsc, unsigned int area, bool bcr3)
+{
+       u32 word;
+
+       word = __raw_readl(bsc + BSC_BCR1);
+       /* check BCR for SDRAM in area */
+       if (((word >> area) & 1) == 0) {
+               dev_err(dev, "Area %u is not configured for SDRAM. BCR1=0x%x\n",
+                       area, word);
+               return -EINVAL;
+       }
+       word |= BSC_BCR1_SLAVE;         /* PCIC BSC is slave only */
+       pcic_writel(word, pcic, PCIC_PCIBCR1);
+
+       word = __raw_readw(bsc + BSC_BCR2);
+       /* check BCR2 for 32bit SDRAM interface*/
+       if (((word >> (area << 1)) & 0x3) != 0x3) {
+               dev_err(dev, "Area %u is not 32 bit SDRAM. BCR2=0x%x\n",
+                       area, word);
+               return -EINVAL;
+       }
+       pcic_writel(word, pcic, PCIC_PCIBCR2);
+
+       if (bcr3) {
+               /* BCR3 have only SH7751R */
+               word = __raw_readw(bsc + BSC_BCR3);
+               pcic_writel(word, pcic, PCIC_PCIBCR3);
+       }
+
+       /* configure the wait control registers */
+       word = __raw_readl(bsc + BSC_WCR1);
+       pcic_writel(word, pcic, PCIC_PCIWCR1);
+       word = __raw_readl(bsc + BSC_WCR2);
+       pcic_writel(word, pcic, PCIC_PCIWCR2);
+       word = __raw_readl(bsc + BSC_WCR3);
+       pcic_writel(word, pcic, PCIC_PCIWCR3);
+       word = __raw_readl(bsc + BSC_MCR);
+       /* Clear MRSET and RFSH bit */
+       word &= ~(BSC_MCR_MRSET | BSC_MCR_RFSH);
+       pcic_writel(word, pcic, PCIC_PCIMCR);
+
+       return 0;
+}
+
+#define NUM_AREA 7
+static int set_pci_ranges(struct device *dev,
+                         void __iomem *pcic, void __iomem *bsc, bool bcr3)
+{
+       struct resource_entry *dma, *tmp;
+       struct pci_host_bridge *bridge;
+       u32 bsc_done[NUM_AREA];
+       unsigned int la;
+
+       bridge = dev_get_drvdata(dev);
+       pcic_writel(0, pcic, PCIC_PCILAR0);
+       pcic_writel(0, pcic, PCIC_PCILAR1);
+       la = 0;
+       memset(&bsc_done, 0, sizeof(bsc_done));
+       resource_list_for_each_entry_safe(dma, tmp, &bridge->dma_ranges) {
+               struct resource *res = dma->res;
+               unsigned int area;
+               u32 word;
+
+               switch (resource_type(res)) {
+               case IORESOURCE_IO:
+                       /* BAR0 is I/O space */
+                       word = res->start | 1;
+                       pcic_writel(word, pcic, PCI_BASE_ADDRESS_0);
+                       word = pcic_readl(pcic, PCI_COMMAND);
+                       word |= PCI_COMMAND_IO;
+                       pcic_writel(word, pcic, PCI_COMMAND);
+                       break;
+               case IORESOURCE_MEM:
+                       if (la > 4) {
+                               dev_err(dev, "Invalid range definition.\n");
+                               return -EINVAL;
+                       }
+                       area = (res->start >> 26) & 0x07;
+                       word = res->end - res->start;
+                       if (area >= NUM_AREA) {
+                               /* Area 7 is reserved. */
+                               dev_info(dev, "Invalid local address 0x%08x. 
Ignore it.\n",
+                                        res->start);
+                               break;
+                       }
+                       pcic_writel(res->start, pcic, PCI_BASE_ADDRESS_1 + la);
+                       /* if dummy entry, skip BSC setup */
+                       if (word < 4)
+                               break;
+                       /* BAR1 is local area 0, BAR2 is local area 1 */
+                       pcic_writel(word, pcic, PCIC_PCILSR0 + la);
+                       word = P2SEGADDR(res->start);
+                       pcic_writel(word, pcic, PCIC_PCILAR0 + la);
+                       la += 4;
+                       if (!bsc_done[area]) {
+                               /* check BCR for SDRAM in specified area. And 
setup PCI BSC. */
+                               if (setup_pci_bsc(dev, pcic, bsc, area, bcr3))
+                                       return -EINVAL;
+                               bsc_done[area] = 1;
+                       }
+                       break;
+               }
+       }
+       return 0;
+}
+
+static int sh7751_pci_probe(struct platform_device *pdev)
+{
+       struct resource *res, *bscres;
+       void __iomem *pcic;
+       void __iomem *bsc;
+       u16 vid, did;
+       u32 word;
+       int ret;
+
+       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       if (IS_ERR(res))
+               return PTR_ERR(res);
+       pcic = ioremap(res->start, res->end - res->start + 1);
+
+       bscres = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+       bsc = devm_ioremap_resource(&pdev->dev, bscres);
+       if (IS_ERR(bsc))
+               return PTR_ERR(bsc);
+
+       /* check for SH7751/SH7751R hardware */
+       word = pcic_readl(pcic, PCI_VENDOR_ID);
+       vid = word & 0xffff;
+       did = word >> 16;
+       if ((vid != PCI_VENDOR_ID_HITACHI) ||
+           ((did != PCI_DEVICE_ID_SH7751) &&
+            (did != PCI_DEVICE_ID_SH7751R))) {
+               dev_err(&pdev->dev, "This is not an SH7751(R)\n");
+               return -ENODEV;
+       }
+       dev_info(&pdev->dev, "PCI core found at %pR\n", res);
+
+       /* Set the BCR's to enable PCI access */
+       word = __raw_readl(bsc + BSC_BCR1);
+       word |= BSC_BCR1_BRQEN;
+       __raw_writel(word, bsc + BSC_BCR1);
+
+       /* Turn the clocks back on (not done in reset)*/
+       pcic_writel(PCIC_WE_KEY | 0, pcic, PCIC_PCICLKR);
+       /* Clear Powerdown IRQ's (not done in reset) */
+       word = PCIC_PCIPINT_D3 | PCIC_PCIPINT_D0;
+       pcic_writel(word, pcic, PCIC_PCIPINT);
+
+       /* set the command/status */
+       word = PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER |
+               PCI_COMMAND_PARITY | PCI_COMMAND_WAIT;
+       pcic_writel(word, pcic, PCI_COMMAND);
+
+       /* define this host as the host bridge */
+       word = PCI_BASE_CLASS_BRIDGE << 24;
+       pcic_writel(word, pcic, PCI_CLASS_REVISION);
+
+       ret = pci_host_common_probe(pdev);
+       if (ret) {
+               dev_err(&pdev->dev, "Initialize failed (%d)\n", ret);
+               return ret;
+       }
+
+       /* Set IO and Mem windows to local address */
+       if (set_pci_ranges(&pdev->dev, pcic, bsc,
+                          did == PCI_DEVICE_ID_SH7751R))
+               return -EINVAL;
+       pcic_writel(0, pcic, PCIC_PCIIOBR);
+
+       if (of_property_read_bool(pdev->dev.of_node, 
"renesas,bus-arbit-round-robin"))
+               word |= BIT(0);
+       else
+               word = 0;
+       pcic_writel(word, pcic, PCIC_PCIDMABT);
+
+       /* SH7751 init done, set central function init complete */
+       /* use round robin mode to stop a device starving/overrunning */
+       word = PCIC_PCICR_CFIN | PCIC_PCICR_ARBM;
+       pcic_writel(PCIC_WE_KEY | word, pcic, PCIC_PCICR);
+
+       return 0;
+}
+
+/*
+ * Direct access to PCI hardware...
+ */
+#define CONFIG_CMD(bus, devfn, where) \
+       (0x80000000 | (bus->number << 16) | (devfn << 8) | (where & ~3))
+
+static void __iomem *sh4_pci_map_bus(struct pci_bus *bus,
+                                    unsigned int devfn, int where)
+{
+       struct pci_config_window *cfg = bus->sysdata;
+       void __iomem *pcic = (void __iomem *)cfg->res.start;
+
+       pcic_writel(CONFIG_CMD(bus, devfn, where), pcic, PCIC_PCIPAR);
+       return pcic + PCIC_PCIPDR;
+}
+
+static const struct pci_ecam_ops pci_sh7751_bus_ops = {
+       .pci_ops        = {
+               .map_bus = sh4_pci_map_bus,
+               .read    = pci_generic_config_read32,
+               .write   = pci_generic_config_write32,
+       }
+};
+
+static const struct of_device_id sh7751_pci_of_match[] = {
+       { .compatible = "renesas,sh7751-pci",
+         .data = &pci_sh7751_bus_ops },
+       { }
+};
+MODULE_DEVICE_TABLE(of, sh7751_pci_of_match);
+
+static struct platform_driver sh7751_pci_driver = {
+       .driver = {
+               .name = "sh7751-pci",
+               .of_match_table = sh7751_pci_of_match,
+       },
+       .probe = sh7751_pci_probe,
+};
+module_platform_driver(sh7751_pci_driver);
+
+MODULE_DESCRIPTION("SH7751 PCI driver");
-- 
2.39.2

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