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>
diff --git a/arch/mips/pci/pci-lantiq.c b/arch/mips/pci/pci-lantiq.c
new file mode 100644
index 0000000..603d749
--- /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 = <q_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(<q_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(<q_pci_driver);
+ if (ret)
+ printk(KERN_INFO "ltq_pci: Error registering platfom driver!");
+ return ret;
+}
+
+arch_initcall(pcibios_init);