@@ -0,0 +1,293 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PCIe host controller driver for Unisoc SoCs
+ *
+ * Copyright (C) 2020-2021 Unisoc, Inc.
+ *
+ * Author: Hongtao Wu <Billows.Wu@unisoc.com>
+ */
+
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/interrupt.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+
+#include "pcie-designware.h"
+
+/* aon apb syscon */
+#define IPA_ACCESS_CFG 0xcd8
+#define AON_ACCESS_PCIE_EN BIT(1)
+
+/* pmu apb syscon */
+#define SNPS_PCIE3_SLP_CTRL 0xac
+#define PERST_N_ASSERT BIT(1)
+#define PERST_N_AUTO_EN BIT(0)
+#define PD_PCIE_CFG_0 0x3e8
+#define PCIE_FORCE_SHUTDOWN BIT(25)
+
+#define PCIE_SS_REG_BASE 0xE00
+#define APB_CLKFREQ_TIMEOUT 0x4
+#define BUSERR_EN BIT(12)
+#define APB_TIMER_DIS BIT(10)
+#define APB_TIMER_LIMIT GENMASK(31, 16)
+
+#define PE0_GEN_CTRL_3 0x58
+#define LTSSM_EN BIT(0)
+
+struct sprd_pcie_soc_data {
+ u32 syscon_offset;
+};
+
+static const struct sprd_pcie_soc_data ums9520_syscon_data = {
+ .syscon_offset = 0x1000, /* The offset of set/clear register */
+};
+
+struct sprd_pcie {
+ u32 syscon_offset;
+ struct device *dev;
+ struct dw_pcie *pci;
+ struct regmap *aon_map;
+ struct regmap *pmu_map;
+ const struct sprd_pcie_soc_data *socdata;
+};
+
+enum sprd_pcie_syscon_type {
+ normal_syscon, /* it's not a set/clear register */
+ set_syscon, /* set a set/clear register */
+ clr_syscon, /* clear a set/clear register */
+};
+
+static void sprd_pcie_buserr_enable(struct dw_pcie *pci)
+{
+ u32 val;
+
+ val = dw_pcie_readl_dbi(pci, PCIE_SS_REG_BASE + APB_CLKFREQ_TIMEOUT);
+ val &= ~APB_TIMER_DIS;
+ val |= BUSERR_EN;
+ val |= APB_TIMER_LIMIT & (0x1f4 << 16);
+ dw_pcie_writel_dbi(pci, PCIE_SS_REG_BASE + APB_CLKFREQ_TIMEOUT, val);
+}
+
+static void sprd_pcie_ltssm_enable(struct dw_pcie *pci, bool enable)
+{
+ u32 val;
+
+ val = dw_pcie_readl_dbi(pci, PCIE_SS_REG_BASE + PE0_GEN_CTRL_3);
+ if (enable)
+ dw_pcie_writel_dbi(pci, PCIE_SS_REG_BASE + PE0_GEN_CTRL_3,
+ val | LTSSM_EN);
+ else
+ dw_pcie_writel_dbi(pci, PCIE_SS_REG_BASE + PE0_GEN_CTRL_3,
+ val & ~LTSSM_EN);
+}
+
+static int sprd_pcie_syscon_set(struct sprd_pcie *ctrl, struct regmap *map,
+ u32 reg, u32 mask, u32 val,
+ enum sprd_pcie_syscon_type type)
+{
+ int ret = 0;
+ u32 read_val;
+ u32 offset = ctrl->syscon_offset;
+ struct device *dev = ctrl->pci->dev;
+
+ /*
+ * Each set/clear register has three registers:
+ * reg: base register
+ * reg + offset: set register
+ * reg + offset * 2: clear register
+ */
+ switch (type) {
+ case normal_syscon:
+ ret = regmap_read(map, reg, &read_val);
+ if (ret) {
+ dev_err(dev, "failed to read register 0x%x\n", reg);
+ return ret;
+ }
+ read_val &= ~mask;
+ read_val |= (val & mask);
+ ret = regmap_write(map, reg, read_val);
+ break;
+ case set_syscon:
+ reg = reg + offset;
+ ret = regmap_write(map, reg, val);
+ break;
+ case clr_syscon:
+ reg = reg + offset * 2;
+ ret = regmap_write(map, reg, val);
+ break;
+ default:
+ break;
+ }
+
+ if (ret)
+ dev_err(dev, "failed to write register 0x%x\n", reg);
+
+ return ret;
+}
+
+static int sprd_pcie_perst_assert(struct sprd_pcie *ctrl)
+{
+ return sprd_pcie_syscon_set(ctrl, ctrl->pmu_map, SNPS_PCIE3_SLP_CTRL,
+ PERST_N_ASSERT, PERST_N_ASSERT, set_syscon);
+}
+
+static int sprd_pcie_perst_deassert(struct sprd_pcie *ctrl)
+{
+ int ret;
+
+ ret = sprd_pcie_syscon_set(ctrl, ctrl->pmu_map, SNPS_PCIE3_SLP_CTRL,
+ PERST_N_ASSERT, 0, clr_syscon);
+ usleep_range(2000, 3000);
+
+ return ret;
+}
+
+static int sprd_pcie_power_on(struct platform_device *pdev)
+{
+ int ret;
+ struct sprd_pcie *ctrl = platform_get_drvdata(pdev);
+ struct dw_pcie *pci = ctrl->pci;
+
+ ret = sprd_pcie_syscon_set(ctrl, ctrl->aon_map, PD_PCIE_CFG_0,
+ PCIE_FORCE_SHUTDOWN, 0, clr_syscon);
+ if (ret)
+ return ret;
+
+ ret = sprd_pcie_syscon_set(ctrl, ctrl->aon_map, IPA_ACCESS_CFG,
+ AON_ACCESS_PCIE_EN, AON_ACCESS_PCIE_EN,
+ set_syscon);
+ if (ret)
+ return ret;
+
+ ret = sprd_pcie_perst_deassert(ctrl);
+ if (ret)
+ return ret;
+
+ sprd_pcie_buserr_enable(pci);
+ sprd_pcie_ltssm_enable(pci, true);
+
+ return ret;
+}
+
+static int sprd_pcie_power_off(struct platform_device *pdev)
+{
+ struct sprd_pcie *ctrl = platform_get_drvdata(pdev);
+ struct dw_pcie *pci = ctrl->pci;
+
+ sprd_pcie_ltssm_enable(pci, false);
+
+ sprd_pcie_perst_assert(ctrl);
+ sprd_pcie_syscon_set(ctrl, ctrl->aon_map, PD_PCIE_CFG_0,
+ PCIE_FORCE_SHUTDOWN, PCIE_FORCE_SHUTDOWN,
+ set_syscon);
+ sprd_pcie_syscon_set(ctrl, ctrl->aon_map, IPA_ACCESS_CFG,
+ AON_ACCESS_PCIE_EN, 0, clr_syscon);
+
+ return 0;
+}
+
+static int sprd_add_pcie_port(struct platform_device *pdev)
+{
+ struct sprd_pcie *ctrl = platform_get_drvdata(pdev);
+ struct dw_pcie *pci = ctrl->pci;
+ struct pcie_port *pp = &pci->pp;
+
+ return dw_pcie_host_init(pp);
+}
+
+static int sprd_pcie_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct sprd_pcie *ctrl;
+ struct dw_pcie *pci;
+ int ret;
+
+ ctrl = devm_kzalloc(dev, sizeof(*ctrl), GFP_KERNEL);
+ if (!ctrl)
+ return -ENOMEM;
+
+ ctrl->socdata =
+ (struct sprd_pcie_soc_data *)of_device_get_match_data(dev);
+ if (!ctrl->socdata) {
+ dev_warn(dev,
+ "using the default set/clear register offset address");
+ ctrl->syscon_offset = 0x1000;
+ }
+ ctrl->syscon_offset = ctrl->socdata->syscon_offset;
+
+ ctrl->aon_map = syscon_regmap_lookup_by_phandle(dev->of_node,
+ "sprd, regmap-aon");
+ if (IS_ERR(ctrl->aon_map)) {
+ dev_err(dev, "failed to get syscon regmap aon\n");
+ ret = PTR_ERR(ctrl->aon_map);
+ goto err;
+ }
+
+ ctrl->pmu_map = syscon_regmap_lookup_by_phandle(dev->of_node,
+ "sprd, regmap-pmu");
+ if (IS_ERR(ctrl->pmu_map)) {
+ dev_err(dev, "failed to get syscon regmap pmu\n");
+ ret = PTR_ERR(ctrl->pmu_map);
+ goto err;
+ }
+
+ pci = ctrl->pci;
+ pci->dev = dev;
+
+ platform_set_drvdata(pdev, ctrl);
+
+ ret = sprd_pcie_power_on(pdev);
+ if (ret < 0) {
+ dev_err(dev, "failed to power on, return %d\n",
+ ret);
+ goto err_power_off;
+ }
+
+ ret = sprd_add_pcie_port(pdev);
+ if (ret) {
+ dev_warn(dev, "failed to initialize RC controller\n");
+ return ret;
+ }
+
+ return 0;
+
+err_power_off:
+ sprd_pcie_power_off(pdev);
+err:
+ return ret;
+}
+
+static int sprd_pcie_remove(struct platform_device *pdev)
+{
+ sprd_pcie_power_off(pdev);
+
+ return 0;
+}
+
+static const struct of_device_id sprd_pcie_of_match[] = {
+ {
+ .compatible = "sprd,ums9520-pcie",
+ .data = &ums9520_syscon_data,
+ },
+ {},
+};
+
+static struct platform_driver sprd_pcie_driver = {
+ .probe = sprd_pcie_probe,
+ .remove = __exit_p(sprd_pcie_remove),
+ .driver = {
+ .name = "sprd-pcie",
+ .of_match_table = sprd_pcie_of_match,
+ },
+};
+
+module_platform_driver(sprd_pcie_driver);
+
+MODULE_DESCRIPTION("Unisoc PCIe host controller driver");
+MODULE_LICENSE("GPL v2");
--