1 files changed, 447 insertions, 0 deletions
diff --git a/arch/mips/pci/pci-ar724x.c b/arch/mips/pci/pci-ar724x.c
new file mode 100644
index 0000000000..807558b251
--- /dev/null
+++ b/arch/mips/pci/pci-ar724x.c
@@ -0,0 +1,447 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  Atheros AR724X PCI host controller driver
+ *
+ *  Copyright (C) 2011 René Bolldorf <xsecute@googlemail.com>
+ *  Copyright (C) 2009-2011 Gabor Juhos <juhosg@openwrt.org>
+ */
+
+#include <linux/irq.h>
+#include <linux/pci.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/platform_device.h>
+#include <asm/mach-ath79/ath79.h>
+#include <asm/mach-ath79/ar71xx_regs.h>
+
+#define AR724X_PCI_REG_APP		0x00
+#define AR724X_PCI_REG_RESET		0x18
+#define AR724X_PCI_REG_INT_STATUS	0x4c
+#define AR724X_PCI_REG_INT_MASK		0x50
+
+#define AR724X_PCI_APP_LTSSM_ENABLE	BIT(0)
+
+#define AR724X_PCI_RESET_LINK_UP	BIT(0)
+
+#define AR724X_PCI_INT_DEV0		BIT(14)
+
+#define AR724X_PCI_IRQ_COUNT		1
+
+#define AR7240_BAR0_WAR_VALUE	0xffff
+
+#define AR724X_PCI_CMD_INIT	(PCI_COMMAND_MEMORY |		\
+				 PCI_COMMAND_MASTER |		\
+				 PCI_COMMAND_INVALIDATE |	\
+				 PCI_COMMAND_PARITY |		\
+				 PCI_COMMAND_SERR |		\
+				 PCI_COMMAND_FAST_BACK)
+
+struct ar724x_pci_controller {
+	void __iomem *devcfg_base;
+	void __iomem *ctrl_base;
+	void __iomem *crp_base;
+
+	int irq;
+	int irq_base;
+
+	bool link_up;
+	bool bar0_is_cached;
+	u32  bar0_value;
+
+	struct pci_controller pci_controller;
+	struct resource io_res;
+	struct resource mem_res;
+};
+
+static inline bool ar724x_pci_check_link(struct ar724x_pci_controller *apc)
+{
+	u32 reset;
+
+	reset = __raw_readl(apc->ctrl_base + AR724X_PCI_REG_RESET);
+	return reset & AR724X_PCI_RESET_LINK_UP;
+}
+
+static inline struct ar724x_pci_controller *
+pci_bus_to_ar724x_controller(struct pci_bus *bus)
+{
+	struct pci_controller *hose;
+
+	hose = (struct pci_controller *) bus->sysdata;
+	return container_of(hose, struct ar724x_pci_controller, pci_controller);
+}
+
+static int ar724x_pci_local_write(struct ar724x_pci_controller *apc,
+				  int where, int size, u32 value)
+{
+	void __iomem *base;
+	u32 data;
+	int s;
+
+	WARN_ON(where & (size - 1));
+
+	if (!apc->link_up)
+		return PCIBIOS_DEVICE_NOT_FOUND;
+
+	base = apc->crp_base;
+	data = __raw_readl(base + (where & ~3));
+
+	switch (size) {
+	case 1:
+		s = ((where & 3) * 8);
+		data &= ~(0xff << s);
+		data |= ((value & 0xff) << s);
+		break;
+	case 2:
+		s = ((where & 2) * 8);
+		data &= ~(0xffff << s);
+		data |= ((value & 0xffff) << s);
+		break;
+	case 4:
+		data = value;
+		break;
+	default:
+		return PCIBIOS_BAD_REGISTER_NUMBER;
+	}
+
+	__raw_writel(data, base + (where & ~3));
+	/* flush write */
+	__raw_readl(base + (where & ~3));
+
+	return PCIBIOS_SUCCESSFUL;
+}
+
+static int ar724x_pci_read(struct pci_bus *bus, unsigned int devfn, int where,
+			    int size, uint32_t *value)
+{
+	struct ar724x_pci_controller *apc;
+	void __iomem *base;
+	u32 data;
+
+	apc = pci_bus_to_ar724x_controller(bus);
+	if (!apc->link_up)
+		return PCIBIOS_DEVICE_NOT_FOUND;
+
+	if (devfn)
+		return PCIBIOS_DEVICE_NOT_FOUND;
+
+	base = apc->devcfg_base;
+	data = __raw_readl(base + (where & ~3));
+
+	switch (size) {
+	case 1:
+		if (where & 1)
+			data >>= 8;
+		if (where & 2)
+			data >>= 16;
+		data &= 0xff;
+		break;
+	case 2:
+		if (where & 2)
+			data >>= 16;
+		data &= 0xffff;
+		break;
+	case 4:
+		break;
+	default:
+		return PCIBIOS_BAD_REGISTER_NUMBER;
+	}
+
+	if (where == PCI_BASE_ADDRESS_0 && size == 4 &&
+	    apc->bar0_is_cached) {
+		/* use the cached value */
+		*value = apc->bar0_value;
+	} else {
+		*value = data;
+	}
+
+	return PCIBIOS_SUCCESSFUL;
+}
+
+static int ar724x_pci_write(struct pci_bus *bus, unsigned int devfn, int where,
+			     int size, uint32_t value)
+{
+	struct ar724x_pci_controller *apc;
+	void __iomem *base;
+	u32 data;
+	int s;
+
+	apc = pci_bus_to_ar724x_controller(bus);
+	if (!apc->link_up)
+		return PCIBIOS_DEVICE_NOT_FOUND;
+
+	if (devfn)
+		return PCIBIOS_DEVICE_NOT_FOUND;
+
+	if (soc_is_ar7240() && where == PCI_BASE_ADDRESS_0 && size == 4) {
+		if (value != 0xffffffff) {
+			/*
+			 * WAR for a hw issue. If the BAR0 register of the
+			 * device is set to the proper base address, the
+			 * memory space of the device is not accessible.
+			 *
+			 * Cache the intended value so it can be read back,
+			 * and write a SoC specific constant value to the
+			 * BAR0 register in order to make the device memory
+			 * accessible.
+			 */
+			apc->bar0_is_cached = true;
+			apc->bar0_value = value;
+
+			value = AR7240_BAR0_WAR_VALUE;
+		} else {
+			apc->bar0_is_cached = false;
+		}
+	}
+
+	base = apc->devcfg_base;
+	data = __raw_readl(base + (where & ~3));
+
+	switch (size) {
+	case 1:
+		s = ((where & 3) * 8);
+		data &= ~(0xff << s);
+		data |= ((value & 0xff) << s);
+		break;
+	case 2:
+		s = ((where & 2) * 8);
+		data &= ~(0xffff << s);
+		data |= ((value & 0xffff) << s);
+		break;
+	case 4:
+		data = value;
+		break;
+	default:
+		return PCIBIOS_BAD_REGISTER_NUMBER;
+	}
+
+	__raw_writel(data, base + (where & ~3));
+	/* flush write */
+	__raw_readl(base + (where & ~3));
+
+	return PCIBIOS_SUCCESSFUL;
+}
+
+static struct pci_ops ar724x_pci_ops = {
+	.read	= ar724x_pci_read,
+	.write	= ar724x_pci_write,
+};
+
+static void ar724x_pci_irq_handler(struct irq_desc *desc)
+{
+	struct ar724x_pci_controller *apc;
+	void __iomem *base;
+	u32 pending;
+
+	apc = irq_desc_get_handler_data(desc);
+	base = apc->ctrl_base;
+
+	pending = __raw_readl(base + AR724X_PCI_REG_INT_STATUS) &
+		  __raw_readl(base + AR724X_PCI_REG_INT_MASK);
+
+	if (pending & AR724X_PCI_INT_DEV0)
+		generic_handle_irq(apc->irq_base + 0);
+
+	else
+		spurious_interrupt();
+}
+
+static void ar724x_pci_irq_unmask(struct irq_data *d)
+{
+	struct ar724x_pci_controller *apc;
+	void __iomem *base;
+	int offset;
+	u32 t;
+
+	apc = irq_data_get_irq_chip_data(d);
+	base = apc->ctrl_base;
+	offset = apc->irq_base - d->irq;
+
+	switch (offset) {
+	case 0:
+		t = __raw_readl(base + AR724X_PCI_REG_INT_MASK);
+		__raw_writel(t | AR724X_PCI_INT_DEV0,
+			     base + AR724X_PCI_REG_INT_MASK);
+		/* flush write */
+		__raw_readl(base + AR724X_PCI_REG_INT_MASK);
+	}
+}
+
+static void ar724x_pci_irq_mask(struct irq_data *d)
+{
+	struct ar724x_pci_controller *apc;
+	void __iomem *base;
+	int offset;
+	u32 t;
+
+	apc = irq_data_get_irq_chip_data(d);
+	base = apc->ctrl_base;
+	offset = apc->irq_base - d->irq;
+
+	switch (offset) {
+	case 0:
+		t = __raw_readl(base + AR724X_PCI_REG_INT_MASK);
+		__raw_writel(t & ~AR724X_PCI_INT_DEV0,
+			     base + AR724X_PCI_REG_INT_MASK);
+
+		/* flush write */
+		__raw_readl(base + AR724X_PCI_REG_INT_MASK);
+
+		t = __raw_readl(base + AR724X_PCI_REG_INT_STATUS);
+		__raw_writel(t | AR724X_PCI_INT_DEV0,
+			     base + AR724X_PCI_REG_INT_STATUS);
+
+		/* flush write */
+		__raw_readl(base + AR724X_PCI_REG_INT_STATUS);
+	}
+}
+
+static struct irq_chip ar724x_pci_irq_chip = {
+	.name		= "AR724X PCI ",
+	.irq_mask	= ar724x_pci_irq_mask,
+	.irq_unmask	= ar724x_pci_irq_unmask,
+	.irq_mask_ack	= ar724x_pci_irq_mask,
+};
+
+static void ar724x_pci_irq_init(struct ar724x_pci_controller *apc,
+				int id)
+{
+	void __iomem *base;
+	int i;
+
+	base = apc->ctrl_base;
+
+	__raw_writel(0, base + AR724X_PCI_REG_INT_MASK);
+	__raw_writel(0, base + AR724X_PCI_REG_INT_STATUS);
+
+	apc->irq_base = ATH79_PCI_IRQ_BASE + (id * AR724X_PCI_IRQ_COUNT);
+
+	for (i = apc->irq_base;
+	     i < apc->irq_base + AR724X_PCI_IRQ_COUNT; i++) {
+		irq_set_chip_and_handler(i, &ar724x_pci_irq_chip,
+					 handle_level_irq);
+		irq_set_chip_data(i, apc);
+	}
+
+	irq_set_chained_handler_and_data(apc->irq, ar724x_pci_irq_handler,
+					 apc);
+}
+
+static void ar724x_pci_hw_init(struct ar724x_pci_controller *apc)
+{
+	u32 ppl, app;
+	int wait = 0;
+
+	/* deassert PCIe host controller and PCIe PHY reset */
+	ath79_device_reset_clear(AR724X_RESET_PCIE);
+	ath79_device_reset_clear(AR724X_RESET_PCIE_PHY);
+
+	/* remove the reset of the PCIE PLL */
+	ppl = ath79_pll_rr(AR724X_PLL_REG_PCIE_CONFIG);
+	ppl &= ~AR724X_PLL_REG_PCIE_CONFIG_PPL_RESET;
+	ath79_pll_wr(AR724X_PLL_REG_PCIE_CONFIG, ppl);
+
+	/* deassert bypass for the PCIE PLL */
+	ppl = ath79_pll_rr(AR724X_PLL_REG_PCIE_CONFIG);
+	ppl &= ~AR724X_PLL_REG_PCIE_CONFIG_PPL_BYPASS;
+	ath79_pll_wr(AR724X_PLL_REG_PCIE_CONFIG, ppl);
+
+	/* set PCIE Application Control to ready */
+	app = __raw_readl(apc->ctrl_base + AR724X_PCI_REG_APP);
+	app |= AR724X_PCI_APP_LTSSM_ENABLE;
+	__raw_writel(app, apc->ctrl_base + AR724X_PCI_REG_APP);
+
+	/* wait up to 100ms for PHY link up */
+	do {
+		mdelay(10);
+		wait++;
+	} while (wait < 10 && !ar724x_pci_check_link(apc));
+}
+
+static int ar724x_pci_probe(struct platform_device *pdev)
+{
+	struct ar724x_pci_controller *apc;
+	struct resource *res;
+	int id;
+
+	id = pdev->id;
+	if (id == -1)
+		id = 0;
+
+	apc = devm_kzalloc(&pdev->dev, sizeof(struct ar724x_pci_controller),
+			    GFP_KERNEL);
+	if (!apc)
+		return -ENOMEM;
+
+	apc->ctrl_base = devm_platform_ioremap_resource_byname(pdev, "ctrl_base");
+	if (IS_ERR(apc->ctrl_base))
+		return PTR_ERR(apc->ctrl_base);
+
+	apc->devcfg_base = devm_platform_ioremap_resource_byname(pdev, "cfg_base");
+	if (IS_ERR(apc->devcfg_base))
+		return PTR_ERR(apc->devcfg_base);
+
+	apc->crp_base = devm_platform_ioremap_resource_byname(pdev, "crp_base");
+	if (IS_ERR(apc->crp_base))
+		return PTR_ERR(apc->crp_base);
+
+	apc->irq = platform_get_irq(pdev, 0);
+	if (apc->irq < 0)
+		return -EINVAL;
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_IO, "io_base");
+	if (!res)
+		return -EINVAL;
+
+	apc->io_res.parent = res;
+	apc->io_res.name = "PCI IO space";
+	apc->io_res.start = res->start;
+	apc->io_res.end = res->end;
+	apc->io_res.flags = IORESOURCE_IO;
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mem_base");
+	if (!res)
+		return -EINVAL;
+
+	apc->mem_res.parent = res;
+	apc->mem_res.name = "PCI memory space";
+	apc->mem_res.start = res->start;
+	apc->mem_res.end = res->end;
+	apc->mem_res.flags = IORESOURCE_MEM;
+
+	apc->pci_controller.pci_ops = &ar724x_pci_ops;
+	apc->pci_controller.io_resource = &apc->io_res;
+	apc->pci_controller.mem_resource = &apc->mem_res;
+
+	/*
+	 * Do the full PCIE Root Complex Initialization Sequence if the PCIe
+	 * host controller is in reset.
+	 */
+	if (ath79_reset_rr(AR724X_RESET_REG_RESET_MODULE) & AR724X_RESET_PCIE)
+		ar724x_pci_hw_init(apc);
+
+	apc->link_up = ar724x_pci_check_link(apc);
+	if (!apc->link_up)
+		dev_warn(&pdev->dev, "PCIe link is down\n");
+
+	ar724x_pci_irq_init(apc, id);
+
+	ar724x_pci_local_write(apc, PCI_COMMAND, 4, AR724X_PCI_CMD_INIT);
+
+	register_pci_controller(&apc->pci_controller);
+
+	return 0;
+}
+
+static struct platform_driver ar724x_pci_driver = {
+	.probe = ar724x_pci_probe,
+	.driver = {
+		.name = "ar724x-pci",
+	},
+};
+
+static int __init ar724x_pci_init(void)
+{
+	return platform_driver_register(&ar724x_pci_driver);
+}
+
+postcore_initcall(ar724x_pci_init);