--- /dev/null
+/*
+ * PCIe host controller driver for Axis ARTPEC-6 SoC
+ *
+ * Based on work done by Phil Edworthy <phil@edworthys.org>
+ *
+ * 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.
+ */
+
+#include <linux/delay.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/platform_device.h>
+#include <linux/resource.h>
+#include <linux/signal.h>
+#include <linux/types.h>
+#include <linux/interrupt.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
+
+#include "pcie-designware.h"
+
+#define to_artpec6_pcie(x) container_of(x, struct artpec6_pcie, pp)
+
+struct artpec6_pcie {
+ struct pcie_port pp;
+ struct regmap *regmap;
+ void __iomem *phy_base;
+};
+
+/* PCIe Port Logic registers (memory-mapped) */
+#define PL_OFFSET 0x700
+#define PCIE_PHY_DEBUG_R0 (PL_OFFSET + 0x28)
+#define PCIE_PHY_DEBUG_R1 (PL_OFFSET + 0x2c)
+
+#define MISC_CONTROL_1_OFF (PL_OFFSET + 0x1bc)
+#define DBI_RO_WR_EN 1
+
+/* ARTPEC-6 specific registers */
+#define PCIECFG 0x18
+#define PCIECFG_DBG_OEN (1 << 24)
+#define PCIECFG_CORE_RESET_REQ (1 << 21)
+#define PCIECFG_LTSSM_ENABLE (1 << 20)
+#define PCIECFG_CLKREQ_B (1 << 11)
+#define PCIECFG_REFCLK_ENABLE (1 << 10)
+#define PCIECFG_PLL_ENABLE (1 << 9)
+#define PCIECFG_PCLK_ENABLE (1 << 8)
+#define PCIECFG_RISRCREN (1 << 4)
+#define PCIECFG_MODE_TX_DRV_EN (1 << 3)
+#define PCIECFG_CISRREN (1 << 2)
+#define PCIECFG_MACRO_ENABLE (1 << 0)
+
+#define NOCCFG 0x40
+#define NOCCFG_ENABLE_CLK_PCIE (1 << 4)
+#define NOCCFG_POWER_PCIE_IDLEACK (1 << 3)
+#define NOCCFG_POWER_PCIE_IDLE (1 << 2)
+#define NOCCFG_POWER_PCIE_IDLEREQ (1 << 1)
+
+#define PHY_STATUS 0x118
+#define PHY_COSPLLLOCK (1 << 0)
+
+#define ARTPEC6_CPU_TO_BUS_ADDR 0x0fffffff
+
+static int artpec6_pcie_establish_link(struct pcie_port *pp)
+{
+ struct artpec6_pcie *artpec6_pcie = to_artpec6_pcie(pp);
+ u32 val;
+ unsigned int retries;
+
+ /* Hold DW core in reset */
+ regmap_read(artpec6_pcie->regmap, PCIECFG, &val);
+ val |= PCIECFG_CORE_RESET_REQ;
+ regmap_write(artpec6_pcie->regmap, PCIECFG, val);
+
+ regmap_read(artpec6_pcie->regmap, PCIECFG, &val);
+ val |= PCIECFG_RISRCREN | /* Receiver term. 50 Ohm */
+ PCIECFG_MODE_TX_DRV_EN |
+ PCIECFG_CISRREN | /* Reference clock term. 100 Ohm */
+ PCIECFG_MACRO_ENABLE;
+ val |= PCIECFG_REFCLK_ENABLE;
+ val &= ~PCIECFG_DBG_OEN;
+ val &= ~PCIECFG_CLKREQ_B;
+ regmap_write(artpec6_pcie->regmap, PCIECFG, val);
+ usleep_range(5000, 6000);
+
+ regmap_read(artpec6_pcie->regmap, NOCCFG, &val);
+ val |= NOCCFG_ENABLE_CLK_PCIE;
+ regmap_write(artpec6_pcie->regmap, NOCCFG, val);
+ usleep_range(20, 30);
+
+ regmap_read(artpec6_pcie->regmap, PCIECFG, &val);
+ val |= PCIECFG_PCLK_ENABLE | PCIECFG_PLL_ENABLE;
+ regmap_write(artpec6_pcie->regmap, PCIECFG, val);
+ usleep_range(6000, 7000);
+
+ regmap_read(artpec6_pcie->regmap, NOCCFG, &val);
+ val &= ~NOCCFG_POWER_PCIE_IDLEREQ;
+ regmap_write(artpec6_pcie->regmap, NOCCFG, val);
+
+ retries = 50;
+ do {
+ usleep_range(1000, 2000);
+ regmap_read(artpec6_pcie->regmap, NOCCFG, &val);
+ retries--;
+ } while (retries &&
+ (val & (NOCCFG_POWER_PCIE_IDLEACK | NOCCFG_POWER_PCIE_IDLE)));
+
+ retries = 50;
+ do {
+ usleep_range(1000, 2000);
+ val = readl(artpec6_pcie->phy_base + PHY_STATUS);
+ retries--;
+ } while (retries && !(val & PHY_COSPLLLOCK));
+
+ /* Take DW core out of reset */
+ regmap_read(artpec6_pcie->regmap, PCIECFG, &val);
+ val &= ~PCIECFG_CORE_RESET_REQ;
+ regmap_write(artpec6_pcie->regmap, PCIECFG, val);
+ usleep_range(100, 200);
+
+ /*
+ * Enable writing to config regs. This is required as the Synopsys
+ * driver changes the class code. That register needs DBI write enable.
+ */
+ writel(DBI_RO_WR_EN, pp->dbi_base + MISC_CONTROL_1_OFF);
+
+ pp->io_base &= ARTPEC6_CPU_TO_BUS_ADDR;
+ pp->mem_base &= ARTPEC6_CPU_TO_BUS_ADDR;
+ pp->cfg0_base &= ARTPEC6_CPU_TO_BUS_ADDR;
+ pp->cfg1_base &= ARTPEC6_CPU_TO_BUS_ADDR;
+
+ /* setup root complex */
+ dw_pcie_setup_rc(pp);
+
+ /* assert LTSSM enable */
+ regmap_read(artpec6_pcie->regmap, PCIECFG, &val);
+ val |= PCIECFG_LTSSM_ENABLE;
+ regmap_write(artpec6_pcie->regmap, PCIECFG, val);
+
+ /* check if the link is up or not */
+ if (!dw_pcie_wait_for_link(pp))
+ return 0;
+
+ dev_dbg(pp->dev, "DEBUG_R0: 0x%08x, DEBUG_R1: 0x%08x\n",
+ readl(pp->dbi_base + PCIE_PHY_DEBUG_R0),
+ readl(pp->dbi_base + PCIE_PHY_DEBUG_R1));
+
+ return -ETIMEDOUT;
+}
+
+static void artpec6_pcie_enable_interrupts(struct pcie_port *pp)
+{
+ if (IS_ENABLED(CONFIG_PCI_MSI))
+ dw_pcie_msi_init(pp);
+}
+
+static void artpec6_pcie_host_init(struct pcie_port *pp)
+{
+ artpec6_pcie_establish_link(pp);
+ artpec6_pcie_enable_interrupts(pp);
+}
+
+static int artpec6_pcie_link_up(struct pcie_port *pp)
+{
+ u32 rc;
+
+ /*
+ * Get status from Synopsys IP
+ * link is debug bit 36, debug register 1 starts at bit 32
+ */
+ rc = readl(pp->dbi_base + PCIE_PHY_DEBUG_R1) & (0x1 << (36 - 32));
+ if (rc)
+ return 1;
+
+ return 0;
+}
+
+static struct pcie_host_ops artpec6_pcie_host_ops = {
+ .link_up = artpec6_pcie_link_up,
+ .host_init = artpec6_pcie_host_init,
+};
+
+static irqreturn_t artpec6_pcie_msi_handler(int irq, void *arg)
+{
+ struct pcie_port *pp = arg;
+
+ return dw_handle_msi_irq(pp);
+}
+
+static int __init artpec6_add_pcie_port(struct pcie_port *pp,
+ struct platform_device *pdev)
+{
+ int ret;
+
+ if (IS_ENABLED(CONFIG_PCI_MSI)) {
+ pp->msi_irq = platform_get_irq_byname(pdev, "msi");
+ if (pp->msi_irq <= 0) {
+ dev_err(&pdev->dev, "failed to get MSI irq\n");
+ return -ENODEV;
+ }
+
+ ret = devm_request_irq(&pdev->dev, pp->msi_irq,
+ artpec6_pcie_msi_handler,
+ IRQF_SHARED | IRQF_NO_THREAD,
+ "artpec6-pcie-msi", pp);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to request MSI irq\n");
+ return ret;
+ }
+ }
+
+ pp->root_bus_nr = -1;
+ pp->ops = &artpec6_pcie_host_ops;
+
+ ret = dw_pcie_host_init(pp);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to initialize host\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+static int artpec6_pcie_probe(struct platform_device *pdev)
+{
+ struct artpec6_pcie *artpec6_pcie;
+ struct pcie_port *pp;
+ struct resource *dbi_base;
+ struct resource *phy_base;
+ int ret;
+
+ artpec6_pcie = devm_kzalloc(&pdev->dev, sizeof(*artpec6_pcie),
+ GFP_KERNEL);
+ if (!artpec6_pcie)
+ return -ENOMEM;
+
+ pp = &artpec6_pcie->pp;
+ pp->dev = &pdev->dev;
+
+ dbi_base = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dbi");
+ pp->dbi_base = devm_ioremap_resource(&pdev->dev, dbi_base);
+ if (IS_ERR(pp->dbi_base))
+ return PTR_ERR(pp->dbi_base);
+
+ phy_base = platform_get_resource_byname(pdev, IORESOURCE_MEM, "phy");
+ artpec6_pcie->phy_base = devm_ioremap_resource(&pdev->dev, phy_base);
+ if (IS_ERR(artpec6_pcie->phy_base))
+ return PTR_ERR(artpec6_pcie->phy_base);
+
+ artpec6_pcie->regmap =
+ syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
+ "axis,syscon-pcie");
+ if (IS_ERR(artpec6_pcie->regmap))
+ return PTR_ERR(artpec6_pcie->regmap);
+
+ ret = artpec6_add_pcie_port(pp, pdev);
+ if (ret < 0)
+ return ret;
+
+ platform_set_drvdata(pdev, artpec6_pcie);
+ return 0;
+}
+
+static const struct of_device_id artpec6_pcie_of_match[] = {
+ { .compatible = "axis,artpec6-pcie", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, artpec6_pcie_of_match);
+
+static struct platform_driver artpec6_pcie_driver = {
+ .probe = artpec6_pcie_probe,
+ .driver = {
+ .name = "artpec6-pcie",
+ .of_match_table = artpec6_pcie_of_match,
+ },
+};
+
+module_platform_driver(artpec6_pcie_driver);
+
+MODULE_AUTHOR("Niklas Cassel <niklas.cassel@axis.com>");
+MODULE_DESCRIPTION("Axis ARTPEC-6 PCIe host controller driver");
+MODULE_LICENSE("GPL v2");
projects / cascardo / linux.git / commitdiff