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-rw-r--r--arch/mips/pci/pci-ar724x.c447
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 000000000..807558b25
--- /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);
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-26 22:47:25 +0000