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>

1 files changed, 297 insertions, 0 deletions

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);