MIPS: Lantiq: Add PCI controller support.

The Lantiq family of SoCs have a EBU (External Bus Unit). This patch adds
the driver that allows us to use the EBU as a PCI controller. In order for
PCI to work the EBU is set to endianess swap all the data. In addition we
need to make use of SWAP_IO_SPACE for device->host DMA to work.

The clock of the PCI works in several modes (internal/external). If this
is not configured correctly the SoC will hang.

Signed-off-by: John Crispin <blogic@openwrt.org>
Signed-off-by: Ralph Hempel <ralph.hempel@lantiq.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2250/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

4 files changed, 432 insertions, 0 deletions

diff --git a/arch/mips/pci/Makefile b/arch/mips/pci/Makefile
index f0d5329289d1..4df879937446 100644
--- a/arch/mips/pci/Makefile
+++ b/arch/mips/pci/Makefile
@@ -41,6 +41,7 @@ obj-$(CONFIG_SIBYTE_SB1250)	+= fixup-sb1250.o pci-sb1250.o
 obj-$(CONFIG_SIBYTE_BCM112X)    += fixup-sb1250.o pci-sb1250.o
 obj-$(CONFIG_SIBYTE_BCM1x80)    += pci-bcm1480.o pci-bcm1480ht.o
 obj-$(CONFIG_SNI_RM)            += fixup-sni.o ops-sni.o
+obj-$(CONFIG_SOC_XWAY)          += pci-lantiq.o ops-lantiq.o
 obj-$(CONFIG_TANBAC_TB0219)     += fixup-tb0219.o
 obj-$(CONFIG_TANBAC_TB0226)     += fixup-tb0226.o
 obj-$(CONFIG_TANBAC_TB0287)     += fixup-tb0287.o
diff --git a/arch/mips/pci/ops-lantiq.c b/arch/mips/pci/ops-lantiq.c
new file mode 100644
index 000000000000..1f2afb55cc71
--- /dev/null
+++ b/arch/mips/pci/ops-lantiq.c
@@ -0,0 +1,116 @@
+/*
+ *  This program is free software; you can redistribute it and/or modify it
+ *  under the terms of the GNU General Public License version 2 as published
+ *  by the Free Software Foundation.
+ *
+ *  Copyright (C) 2010 John Crispin <blogic@openwrt.org>
+ */
+
+#include <linux/types.h>
+#include <linux/pci.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/mm.h>
+#include <asm/addrspace.h>
+#include <linux/vmalloc.h>
+
+#include <lantiq_soc.h>
+
+#include "pci-lantiq.h"
+
+#define LTQ_PCI_CFG_BUSNUM_SHF 16
+#define LTQ_PCI_CFG_DEVNUM_SHF 11
+#define LTQ_PCI_CFG_FUNNUM_SHF 8
+
+#define PCI_ACCESS_READ  0
+#define PCI_ACCESS_WRITE 1
+
+static int ltq_pci_config_access(unsigned char access_type, struct pci_bus *bus,
+        unsigned int devfn, unsigned int where, u32 *data)
+{
+        unsigned long cfg_base;
+        unsigned long flags;
+        u32 temp;
+
+        /* we support slot from 0 to 15 dev_fn & 0x68 (AD29) is the
+           SoC itself */
+        if ((bus->number != 0) || ((devfn & 0xf8) > 0x78)
+                || ((devfn & 0xf8) == 0) || ((devfn & 0xf8) == 0x68))
+                return 1;
+
+        spin_lock_irqsave(&ebu_lock, flags);
+
+        cfg_base = (unsigned long) ltq_pci_mapped_cfg;
+        cfg_base |= (bus->number << LTQ_PCI_CFG_BUSNUM_SHF) | (devfn <<
+                        LTQ_PCI_CFG_FUNNUM_SHF) | (where & ~0x3);
+
+        /* Perform access */
+        if (access_type == PCI_ACCESS_WRITE) {
+                ltq_w32(swab32(*data), ((u32 *)cfg_base));
+        } else {
+                *data = ltq_r32(((u32 *)(cfg_base)));
+                *data = swab32(*data);
+        }
+        wmb();
+
+        /* clean possible Master abort */
+        cfg_base = (unsigned long) ltq_pci_mapped_cfg;
+        cfg_base |= (0x0 << LTQ_PCI_CFG_FUNNUM_SHF) + 4;
+        temp = ltq_r32(((u32 *)(cfg_base)));
+        temp = swab32(temp);
+        cfg_base = (unsigned long) ltq_pci_mapped_cfg;
+        cfg_base |= (0x68 << LTQ_PCI_CFG_FUNNUM_SHF) + 4;
+        ltq_w32(temp, ((u32 *)cfg_base));
+
+        spin_unlock_irqrestore(&ebu_lock, flags);
+
+        if (((*data) == 0xffffffff) && (access_type == PCI_ACCESS_READ))
+                return 1;
+
+        return 0;
+}
+
+int ltq_pci_read_config_dword(struct pci_bus *bus, unsigned int devfn,
+        int where, int size, u32 *val)
+{
+        u32 data = 0;
+
+        if (ltq_pci_config_access(PCI_ACCESS_READ, bus, devfn, where, &data))
+                return PCIBIOS_DEVICE_NOT_FOUND;
+
+        if (size == 1)
+                *val = (data >> ((where & 3) << 3)) & 0xff;
+        else if (size == 2)
+                *val = (data >> ((where & 3) << 3)) & 0xffff;
+        else
+                *val = data;
+
+        return PCIBIOS_SUCCESSFUL;
+}
+
+int ltq_pci_write_config_dword(struct pci_bus *bus, unsigned int devfn,
+        int where, int size, u32 val)
+{
+        u32 data = 0;
+
+        if (size == 4) {
+                data = val;
+        } else {
+                if (ltq_pci_config_access(PCI_ACCESS_READ, bus,
+                                devfn, where, &data))
+                        return PCIBIOS_DEVICE_NOT_FOUND;
+
+                if (size == 1)
+                        data = (data & ~(0xff << ((where & 3) << 3))) |
+                                (val << ((where & 3) << 3));
+                else if (size == 2)
+                        data = (data & ~(0xffff << ((where & 3) << 3))) |
+                                (val << ((where & 3) << 3));
+        }
+
+        if (ltq_pci_config_access(PCI_ACCESS_WRITE, bus, devfn, where, &data))
+                return PCIBIOS_DEVICE_NOT_FOUND;
+
+        return PCIBIOS_SUCCESSFUL;
+}
diff --git a/arch/mips/pci/pci-lantiq.c b/arch/mips/pci/pci-lantiq.c
new file mode 100644
index 000000000000..603d7493e966
--- /dev/null
+++ b/arch/mips/pci/pci-lantiq.c
@@ -0,0 +1,297 @@
+/*
+ *  This program is free software; you can redistribute it and/or modify it
+ *  under the terms of the GNU General Public License version 2 as published
+ *  by the Free Software Foundation.
+ *
+ *  Copyright (C) 2010 John Crispin <blogic@openwrt.org>
+ */
+
+#include <linux/types.h>
+#include <linux/pci.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/mm.h>
+#include <linux/vmalloc.h>
+#include <linux/platform_device.h>
+
+#include <asm/pci.h>
+#include <asm/gpio.h>
+#include <asm/addrspace.h>
+
+#include <lantiq_soc.h>
+#include <lantiq_irq.h>
+#include <lantiq_platform.h>
+
+#include "pci-lantiq.h"
+
+#define LTQ_PCI_CFG_BASE                0x17000000
+#define LTQ_PCI_CFG_SIZE                0x00008000
+#define LTQ_PCI_MEM_BASE                0x18000000
+#define LTQ_PCI_MEM_SIZE                0x02000000
+#define LTQ_PCI_IO_BASE                 0x1AE00000
+#define LTQ_PCI_IO_SIZE                 0x00200000
+
+#define PCI_CR_FCI_ADDR_MAP0            0x00C0
+#define PCI_CR_FCI_ADDR_MAP1            0x00C4
+#define PCI_CR_FCI_ADDR_MAP2            0x00C8
+#define PCI_CR_FCI_ADDR_MAP3            0x00CC
+#define PCI_CR_FCI_ADDR_MAP4            0x00D0
+#define PCI_CR_FCI_ADDR_MAP5            0x00D4
+#define PCI_CR_FCI_ADDR_MAP6            0x00D8
+#define PCI_CR_FCI_ADDR_MAP7            0x00DC
+#define PCI_CR_CLK_CTRL                 0x0000
+#define PCI_CR_PCI_MOD                  0x0030
+#define PCI_CR_PC_ARB                   0x0080
+#define PCI_CR_FCI_ADDR_MAP11hg         0x00E4
+#define PCI_CR_BAR11MASK                0x0044
+#define PCI_CR_BAR12MASK                0x0048
+#define PCI_CR_BAR13MASK                0x004C
+#define PCI_CS_BASE_ADDR1               0x0010
+#define PCI_CR_PCI_ADDR_MAP11           0x0064
+#define PCI_CR_FCI_BURST_LENGTH         0x00E8
+#define PCI_CR_PCI_EOI                  0x002C
+#define PCI_CS_STS_CMD                  0x0004
+
+#define PCI_MASTER0_REQ_MASK_2BITS      8
+#define PCI_MASTER1_REQ_MASK_2BITS      10
+#define PCI_MASTER2_REQ_MASK_2BITS      12
+#define INTERNAL_ARB_ENABLE_BIT         0
+
+#define LTQ_CGU_IFCCR           0x0018
+#define LTQ_CGU_PCICR           0x0034
+
+#define ltq_pci_w32(x, y)       ltq_w32((x), ltq_pci_membase + (y))
+#define ltq_pci_r32(x)          ltq_r32(ltq_pci_membase + (x))
+
+#define ltq_pci_cfg_w32(x, y)   ltq_w32((x), ltq_pci_mapped_cfg + (y))
+#define ltq_pci_cfg_r32(x)      ltq_r32(ltq_pci_mapped_cfg + (x))
+
+struct ltq_pci_gpio_map {
+        int pin;
+        int alt0;
+        int alt1;
+        int dir;
+        char *name;
+};
+
+/* the pci core can make use of the following gpios */
+static struct ltq_pci_gpio_map ltq_pci_gpio_map[] = {
+        { 0, 1, 0, 0, "pci-exin0" },
+        { 1, 1, 0, 0, "pci-exin1" },
+        { 2, 1, 0, 0, "pci-exin2" },
+        { 39, 1, 0, 0, "pci-exin3" },
+        { 10, 1, 0, 0, "pci-exin4" },
+        { 9, 1, 0, 0, "pci-exin5" },
+        { 30, 1, 0, 1, "pci-gnt1" },
+        { 23, 1, 0, 1, "pci-gnt2" },
+        { 19, 1, 0, 1, "pci-gnt3" },
+        { 38, 1, 0, 1, "pci-gnt4" },
+        { 29, 1, 0, 0, "pci-req1" },
+        { 31, 1, 0, 0, "pci-req2" },
+        { 3, 1, 0, 0, "pci-req3" },
+        { 37, 1, 0, 0, "pci-req4" },
+};
+
+__iomem void *ltq_pci_mapped_cfg;
+static __iomem void *ltq_pci_membase;
+
+int (*ltqpci_plat_dev_init)(struct pci_dev *dev) = NULL;
+
+/* Since the PCI REQ pins can be reused for other functionality, make it
+   possible to exclude those from interpretation by the PCI controller */
+static int ltq_pci_req_mask = 0xf;
+
+static int *ltq_pci_irq_map;
+
+struct pci_ops ltq_pci_ops = {
+        .read   = ltq_pci_read_config_dword,
+        .write  = ltq_pci_write_config_dword
+};
+
+static struct resource pci_io_resource = {
+        .name   = "pci io space",
+        .start  = LTQ_PCI_IO_BASE,
+        .end    = LTQ_PCI_IO_BASE + LTQ_PCI_IO_SIZE - 1,
+        .flags  = IORESOURCE_IO
+};
+
+static struct resource pci_mem_resource = {
+        .name   = "pci memory space",
+        .start  = LTQ_PCI_MEM_BASE,
+        .end    = LTQ_PCI_MEM_BASE + LTQ_PCI_MEM_SIZE - 1,
+        .flags  = IORESOURCE_MEM
+};
+
+static struct pci_controller ltq_pci_controller = {
+        .pci_ops        = &ltq_pci_ops,
+        .mem_resource   = &pci_mem_resource,
+        .mem_offset     = 0x00000000UL,
+        .io_resource    = &pci_io_resource,
+        .io_offset      = 0x00000000UL,
+};
+
+int pcibios_plat_dev_init(struct pci_dev *dev)
+{
+        if (ltqpci_plat_dev_init)
+                return ltqpci_plat_dev_init(dev);
+
+        return 0;
+}
+
+static u32 ltq_calc_bar11mask(void)
+{
+        u32 mem, bar11mask;
+
+        /* BAR11MASK value depends on available memory on system. */
+        mem = num_physpages * PAGE_SIZE;
+        bar11mask = (0x0ffffff0 & ~((1 << (fls(mem) - 1)) - 1)) | 8;
+
+        return bar11mask;
+}
+
+static void ltq_pci_setup_gpio(int gpio)
+{
+        int i;
+        for (i = 0; i < ARRAY_SIZE(ltq_pci_gpio_map); i++) {
+                if (gpio & (1 << i)) {
+                        ltq_gpio_request(ltq_pci_gpio_map[i].pin,
+                                ltq_pci_gpio_map[i].alt0,
+                                ltq_pci_gpio_map[i].alt1,
+                                ltq_pci_gpio_map[i].dir,
+                                ltq_pci_gpio_map[i].name);
+                }
+        }
+        ltq_gpio_request(21, 0, 0, 1, "pci-reset");
+        ltq_pci_req_mask = (gpio >> PCI_REQ_SHIFT) & PCI_REQ_MASK;
+}
+
+static int __devinit ltq_pci_startup(struct ltq_pci_data *conf)
+{
+        u32 temp_buffer;
+
+        /* set clock to 33Mhz */
+        ltq_cgu_w32(ltq_cgu_r32(LTQ_CGU_IFCCR) & ~0xf00000, LTQ_CGU_IFCCR);
+        ltq_cgu_w32(ltq_cgu_r32(LTQ_CGU_IFCCR) | 0x800000, LTQ_CGU_IFCCR);
+
+        /* external or internal clock ? */
+        if (conf->clock) {
+                ltq_cgu_w32(ltq_cgu_r32(LTQ_CGU_IFCCR) & ~(1 << 16),
+                        LTQ_CGU_IFCCR);
+                ltq_cgu_w32((1 << 30), LTQ_CGU_PCICR);
+        } else {
+                ltq_cgu_w32(ltq_cgu_r32(LTQ_CGU_IFCCR) | (1 << 16),
+                        LTQ_CGU_IFCCR);
+                ltq_cgu_w32((1 << 31) | (1 << 30), LTQ_CGU_PCICR);
+        }
+
+        /* setup pci clock and gpis used by pci */
+        ltq_pci_setup_gpio(conf->gpio);
+
+        /* enable auto-switching between PCI and EBU */
+        ltq_pci_w32(0xa, PCI_CR_CLK_CTRL);
+
+        /* busy, i.e. configuration is not done, PCI access has to be retried */
+        ltq_pci_w32(ltq_pci_r32(PCI_CR_PCI_MOD) & ~(1 << 24), PCI_CR_PCI_MOD);
+        wmb();
+        /* BUS Master/IO/MEM access */
+        ltq_pci_cfg_w32(ltq_pci_cfg_r32(PCI_CS_STS_CMD) | 7, PCI_CS_STS_CMD);
+
+        /* enable external 2 PCI masters */
+        temp_buffer = ltq_pci_r32(PCI_CR_PC_ARB);
+        temp_buffer &= (~(ltq_pci_req_mask << 16));
+        /* enable internal arbiter */
+        temp_buffer |= (1 << INTERNAL_ARB_ENABLE_BIT);
+        /* enable internal PCI master reqest */
+        temp_buffer &= (~(3 << PCI_MASTER0_REQ_MASK_2BITS));
+
+        /* enable EBU request */
+        temp_buffer &= (~(3 << PCI_MASTER1_REQ_MASK_2BITS));
+
+        /* enable all external masters request */
+        temp_buffer &= (~(3 << PCI_MASTER2_REQ_MASK_2BITS));
+        ltq_pci_w32(temp_buffer, PCI_CR_PC_ARB);
+        wmb();
+
+        /* setup BAR memory regions */
+        ltq_pci_w32(0x18000000, PCI_CR_FCI_ADDR_MAP0);
+        ltq_pci_w32(0x18400000, PCI_CR_FCI_ADDR_MAP1);
+        ltq_pci_w32(0x18800000, PCI_CR_FCI_ADDR_MAP2);
+        ltq_pci_w32(0x18c00000, PCI_CR_FCI_ADDR_MAP3);
+        ltq_pci_w32(0x19000000, PCI_CR_FCI_ADDR_MAP4);
+        ltq_pci_w32(0x19400000, PCI_CR_FCI_ADDR_MAP5);
+        ltq_pci_w32(0x19800000, PCI_CR_FCI_ADDR_MAP6);
+        ltq_pci_w32(0x19c00000, PCI_CR_FCI_ADDR_MAP7);
+        ltq_pci_w32(0x1ae00000, PCI_CR_FCI_ADDR_MAP11hg);
+        ltq_pci_w32(ltq_calc_bar11mask(), PCI_CR_BAR11MASK);
+        ltq_pci_w32(0, PCI_CR_PCI_ADDR_MAP11);
+        ltq_pci_w32(0, PCI_CS_BASE_ADDR1);
+        /* both TX and RX endian swap are enabled */
+        ltq_pci_w32(ltq_pci_r32(PCI_CR_PCI_EOI) | 3, PCI_CR_PCI_EOI);
+        wmb();
+        ltq_pci_w32(ltq_pci_r32(PCI_CR_BAR12MASK) | 0x80000000,
+                PCI_CR_BAR12MASK);
+        ltq_pci_w32(ltq_pci_r32(PCI_CR_BAR13MASK) | 0x80000000,
+                PCI_CR_BAR13MASK);
+        /*use 8 dw burst length */
+        ltq_pci_w32(0x303, PCI_CR_FCI_BURST_LENGTH);
+        ltq_pci_w32(ltq_pci_r32(PCI_CR_PCI_MOD) | (1 << 24), PCI_CR_PCI_MOD);
+        wmb();
+
+        /* setup irq line */
+        ltq_ebu_w32(ltq_ebu_r32(LTQ_EBU_PCC_CON) | 0xc, LTQ_EBU_PCC_CON);
+        ltq_ebu_w32(ltq_ebu_r32(LTQ_EBU_PCC_IEN) | 0x10, LTQ_EBU_PCC_IEN);
+
+        /* toggle reset pin */
+        __gpio_set_value(21, 0);
+        wmb();
+        mdelay(1);
+        __gpio_set_value(21, 1);
+        return 0;
+}
+
+int __init pcibios_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
+{
+        if (ltq_pci_irq_map[slot])
+                return ltq_pci_irq_map[slot];
+        printk(KERN_ERR "lq_pci: trying to map irq for unknown slot %d\n",
+                slot);
+
+        return 0;
+}
+
+static int __devinit ltq_pci_probe(struct platform_device *pdev)
+{
+        struct ltq_pci_data *ltq_pci_data =
+                (struct ltq_pci_data *) pdev->dev.platform_data;
+        pci_probe_only = 0;
+        ltq_pci_irq_map = ltq_pci_data->irq;
+        ltq_pci_membase = ioremap_nocache(PCI_CR_BASE_ADDR, PCI_CR_SIZE);
+        ltq_pci_mapped_cfg =
+                ioremap_nocache(LTQ_PCI_CFG_BASE, LTQ_PCI_CFG_BASE);
+        ltq_pci_controller.io_map_base =
+                (unsigned long)ioremap(LTQ_PCI_IO_BASE, LTQ_PCI_IO_SIZE - 1);
+        ltq_pci_startup(ltq_pci_data);
+        register_pci_controller(&ltq_pci_controller);
+
+        return 0;
+}
+
+static struct platform_driver
+ltq_pci_driver = {
+        .probe = ltq_pci_probe,
+        .driver = {
+                .name = "ltq_pci",
+                .owner = THIS_MODULE,
+        },
+};
+
+int __init pcibios_init(void)
+{
+        int ret = platform_driver_register(&ltq_pci_driver);
+        if (ret)
+                printk(KERN_INFO "ltq_pci: Error registering platfom driver!");
+        return ret;
+}
+
+arch_initcall(pcibios_init);
diff --git a/arch/mips/pci/pci-lantiq.h b/arch/mips/pci/pci-lantiq.h
new file mode 100644
index 000000000000..66bf6cd6be3c
--- /dev/null
+++ b/arch/mips/pci/pci-lantiq.h
@@ -0,0 +1,18 @@
+/*
+ *  This program is free software; you can redistribute it and/or modify it
+ *  under the terms of the GNU General Public License version 2 as published
+ *  by the Free Software Foundation.
+ *
+ *  Copyright (C) 2010 John Crispin <blogic@openwrt.org>
+ */
+
+#ifndef _LTQ_PCI_H__
+#define _LTQ_PCI_H__
+
+extern __iomem void *ltq_pci_mapped_cfg;
+extern int ltq_pci_read_config_dword(struct pci_bus *bus,
+        unsigned int devfn, int where, int size, u32 *val);
+extern int ltq_pci_write_config_dword(struct pci_bus *bus,
+        unsigned int devfn, int where, int size, u32 val);
+
+#endif