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path: root/drivers/pci/controller/dwc/pcie-dw-rockchip.c
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Diffstat (limited to 'drivers/pci/controller/dwc/pcie-dw-rockchip.c')
-rw-r--r--drivers/pci/controller/dwc/pcie-dw-rockchip.c368
1 files changed, 368 insertions, 0 deletions
diff --git a/drivers/pci/controller/dwc/pcie-dw-rockchip.c b/drivers/pci/controller/dwc/pcie-dw-rockchip.c
new file mode 100644
index 0000000000..2fe42c7009
--- /dev/null
+++ b/drivers/pci/controller/dwc/pcie-dw-rockchip.c
@@ -0,0 +1,368 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PCIe host controller driver for Rockchip SoCs.
+ *
+ * Copyright (C) 2021 Rockchip Electronics Co., Ltd.
+ * http://www.rock-chips.com
+ *
+ * Author: Simon Xue <xxm@rock-chips.com>
+ */
+
+#include <linux/clk.h>
+#include <linux/gpio/consumer.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/irqdomain.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/reset.h>
+
+#include "pcie-designware.h"
+
+/*
+ * The upper 16 bits of PCIE_CLIENT_CONFIG are a write
+ * mask for the lower 16 bits.
+ */
+#define HIWORD_UPDATE(mask, val) (((mask) << 16) | (val))
+#define HIWORD_UPDATE_BIT(val) HIWORD_UPDATE(val, val)
+#define HIWORD_DISABLE_BIT(val) HIWORD_UPDATE(val, ~val)
+
+#define to_rockchip_pcie(x) dev_get_drvdata((x)->dev)
+
+#define PCIE_CLIENT_RC_MODE HIWORD_UPDATE_BIT(0x40)
+#define PCIE_CLIENT_ENABLE_LTSSM HIWORD_UPDATE_BIT(0xc)
+#define PCIE_SMLH_LINKUP BIT(16)
+#define PCIE_RDLH_LINKUP BIT(17)
+#define PCIE_LINKUP (PCIE_SMLH_LINKUP | PCIE_RDLH_LINKUP)
+#define PCIE_L0S_ENTRY 0x11
+#define PCIE_CLIENT_GENERAL_CONTROL 0x0
+#define PCIE_CLIENT_INTR_STATUS_LEGACY 0x8
+#define PCIE_CLIENT_INTR_MASK_LEGACY 0x1c
+#define PCIE_CLIENT_GENERAL_DEBUG 0x104
+#define PCIE_CLIENT_HOT_RESET_CTRL 0x180
+#define PCIE_CLIENT_LTSSM_STATUS 0x300
+#define PCIE_LTSSM_ENABLE_ENHANCE BIT(4)
+#define PCIE_LTSSM_STATUS_MASK GENMASK(5, 0)
+
+struct rockchip_pcie {
+ struct dw_pcie pci;
+ void __iomem *apb_base;
+ struct phy *phy;
+ struct clk_bulk_data *clks;
+ unsigned int clk_cnt;
+ struct reset_control *rst;
+ struct gpio_desc *rst_gpio;
+ struct regulator *vpcie3v3;
+ struct irq_domain *irq_domain;
+};
+
+static int rockchip_pcie_readl_apb(struct rockchip_pcie *rockchip,
+ u32 reg)
+{
+ return readl_relaxed(rockchip->apb_base + reg);
+}
+
+static void rockchip_pcie_writel_apb(struct rockchip_pcie *rockchip,
+ u32 val, u32 reg)
+{
+ writel_relaxed(val, rockchip->apb_base + reg);
+}
+
+static void rockchip_pcie_legacy_int_handler(struct irq_desc *desc)
+{
+ struct irq_chip *chip = irq_desc_get_chip(desc);
+ struct rockchip_pcie *rockchip = irq_desc_get_handler_data(desc);
+ unsigned long reg, hwirq;
+
+ chained_irq_enter(chip, desc);
+
+ reg = rockchip_pcie_readl_apb(rockchip, PCIE_CLIENT_INTR_STATUS_LEGACY);
+
+ for_each_set_bit(hwirq, &reg, 4)
+ generic_handle_domain_irq(rockchip->irq_domain, hwirq);
+
+ chained_irq_exit(chip, desc);
+}
+
+static void rockchip_intx_mask(struct irq_data *data)
+{
+ rockchip_pcie_writel_apb(irq_data_get_irq_chip_data(data),
+ HIWORD_UPDATE_BIT(BIT(data->hwirq)),
+ PCIE_CLIENT_INTR_MASK_LEGACY);
+};
+
+static void rockchip_intx_unmask(struct irq_data *data)
+{
+ rockchip_pcie_writel_apb(irq_data_get_irq_chip_data(data),
+ HIWORD_DISABLE_BIT(BIT(data->hwirq)),
+ PCIE_CLIENT_INTR_MASK_LEGACY);
+};
+
+static struct irq_chip rockchip_intx_irq_chip = {
+ .name = "INTx",
+ .irq_mask = rockchip_intx_mask,
+ .irq_unmask = rockchip_intx_unmask,
+ .flags = IRQCHIP_SKIP_SET_WAKE | IRQCHIP_MASK_ON_SUSPEND,
+};
+
+static int rockchip_pcie_intx_map(struct irq_domain *domain, unsigned int irq,
+ irq_hw_number_t hwirq)
+{
+ irq_set_chip_and_handler(irq, &rockchip_intx_irq_chip, handle_level_irq);
+ irq_set_chip_data(irq, domain->host_data);
+
+ return 0;
+}
+
+static const struct irq_domain_ops intx_domain_ops = {
+ .map = rockchip_pcie_intx_map,
+};
+
+static int rockchip_pcie_init_irq_domain(struct rockchip_pcie *rockchip)
+{
+ struct device *dev = rockchip->pci.dev;
+ struct device_node *intc;
+
+ intc = of_get_child_by_name(dev->of_node, "legacy-interrupt-controller");
+ if (!intc) {
+ dev_err(dev, "missing child interrupt-controller node\n");
+ return -EINVAL;
+ }
+
+ rockchip->irq_domain = irq_domain_add_linear(intc, PCI_NUM_INTX,
+ &intx_domain_ops, rockchip);
+ of_node_put(intc);
+ if (!rockchip->irq_domain) {
+ dev_err(dev, "failed to get a INTx IRQ domain\n");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static void rockchip_pcie_enable_ltssm(struct rockchip_pcie *rockchip)
+{
+ rockchip_pcie_writel_apb(rockchip, PCIE_CLIENT_ENABLE_LTSSM,
+ PCIE_CLIENT_GENERAL_CONTROL);
+}
+
+static int rockchip_pcie_link_up(struct dw_pcie *pci)
+{
+ struct rockchip_pcie *rockchip = to_rockchip_pcie(pci);
+ u32 val = rockchip_pcie_readl_apb(rockchip, PCIE_CLIENT_LTSSM_STATUS);
+
+ if ((val & PCIE_LINKUP) == PCIE_LINKUP &&
+ (val & PCIE_LTSSM_STATUS_MASK) == PCIE_L0S_ENTRY)
+ return 1;
+
+ return 0;
+}
+
+static int rockchip_pcie_start_link(struct dw_pcie *pci)
+{
+ struct rockchip_pcie *rockchip = to_rockchip_pcie(pci);
+
+ /* Reset device */
+ gpiod_set_value_cansleep(rockchip->rst_gpio, 0);
+
+ rockchip_pcie_enable_ltssm(rockchip);
+
+ /*
+ * PCIe requires the refclk to be stable for 100µs prior to releasing
+ * PERST. See table 2-4 in section 2.6.2 AC Specifications of the PCI
+ * Express Card Electromechanical Specification, 1.1. However, we don't
+ * know if the refclk is coming from RC's PHY or external OSC. If it's
+ * from RC, so enabling LTSSM is the just right place to release #PERST.
+ * We need more extra time as before, rather than setting just
+ * 100us as we don't know how long should the device need to reset.
+ */
+ msleep(100);
+ gpiod_set_value_cansleep(rockchip->rst_gpio, 1);
+
+ return 0;
+}
+
+static int rockchip_pcie_host_init(struct dw_pcie_rp *pp)
+{
+ struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+ struct rockchip_pcie *rockchip = to_rockchip_pcie(pci);
+ struct device *dev = rockchip->pci.dev;
+ u32 val = HIWORD_UPDATE_BIT(PCIE_LTSSM_ENABLE_ENHANCE);
+ int irq, ret;
+
+ irq = of_irq_get_byname(dev->of_node, "legacy");
+ if (irq < 0)
+ return irq;
+
+ ret = rockchip_pcie_init_irq_domain(rockchip);
+ if (ret < 0)
+ dev_err(dev, "failed to init irq domain\n");
+
+ irq_set_chained_handler_and_data(irq, rockchip_pcie_legacy_int_handler,
+ rockchip);
+
+ /* LTSSM enable control mode */
+ rockchip_pcie_writel_apb(rockchip, val, PCIE_CLIENT_HOT_RESET_CTRL);
+
+ rockchip_pcie_writel_apb(rockchip, PCIE_CLIENT_RC_MODE,
+ PCIE_CLIENT_GENERAL_CONTROL);
+
+ return 0;
+}
+
+static const struct dw_pcie_host_ops rockchip_pcie_host_ops = {
+ .host_init = rockchip_pcie_host_init,
+};
+
+static int rockchip_pcie_clk_init(struct rockchip_pcie *rockchip)
+{
+ struct device *dev = rockchip->pci.dev;
+ int ret;
+
+ ret = devm_clk_bulk_get_all(dev, &rockchip->clks);
+ if (ret < 0)
+ return ret;
+
+ rockchip->clk_cnt = ret;
+
+ return clk_bulk_prepare_enable(rockchip->clk_cnt, rockchip->clks);
+}
+
+static int rockchip_pcie_resource_get(struct platform_device *pdev,
+ struct rockchip_pcie *rockchip)
+{
+ rockchip->apb_base = devm_platform_ioremap_resource_byname(pdev, "apb");
+ if (IS_ERR(rockchip->apb_base))
+ return PTR_ERR(rockchip->apb_base);
+
+ rockchip->rst_gpio = devm_gpiod_get_optional(&pdev->dev, "reset",
+ GPIOD_OUT_HIGH);
+ if (IS_ERR(rockchip->rst_gpio))
+ return PTR_ERR(rockchip->rst_gpio);
+
+ rockchip->rst = devm_reset_control_array_get_exclusive(&pdev->dev);
+ if (IS_ERR(rockchip->rst))
+ return dev_err_probe(&pdev->dev, PTR_ERR(rockchip->rst),
+ "failed to get reset lines\n");
+
+ return 0;
+}
+
+static int rockchip_pcie_phy_init(struct rockchip_pcie *rockchip)
+{
+ struct device *dev = rockchip->pci.dev;
+ int ret;
+
+ rockchip->phy = devm_phy_get(dev, "pcie-phy");
+ if (IS_ERR(rockchip->phy))
+ return dev_err_probe(dev, PTR_ERR(rockchip->phy),
+ "missing PHY\n");
+
+ ret = phy_init(rockchip->phy);
+ if (ret < 0)
+ return ret;
+
+ ret = phy_power_on(rockchip->phy);
+ if (ret)
+ phy_exit(rockchip->phy);
+
+ return ret;
+}
+
+static void rockchip_pcie_phy_deinit(struct rockchip_pcie *rockchip)
+{
+ phy_exit(rockchip->phy);
+ phy_power_off(rockchip->phy);
+}
+
+static const struct dw_pcie_ops dw_pcie_ops = {
+ .link_up = rockchip_pcie_link_up,
+ .start_link = rockchip_pcie_start_link,
+};
+
+static int rockchip_pcie_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct rockchip_pcie *rockchip;
+ struct dw_pcie_rp *pp;
+ int ret;
+
+ rockchip = devm_kzalloc(dev, sizeof(*rockchip), GFP_KERNEL);
+ if (!rockchip)
+ return -ENOMEM;
+
+ platform_set_drvdata(pdev, rockchip);
+
+ rockchip->pci.dev = dev;
+ rockchip->pci.ops = &dw_pcie_ops;
+
+ pp = &rockchip->pci.pp;
+ pp->ops = &rockchip_pcie_host_ops;
+
+ ret = rockchip_pcie_resource_get(pdev, rockchip);
+ if (ret)
+ return ret;
+
+ ret = reset_control_assert(rockchip->rst);
+ if (ret)
+ return ret;
+
+ /* DON'T MOVE ME: must be enable before PHY init */
+ rockchip->vpcie3v3 = devm_regulator_get_optional(dev, "vpcie3v3");
+ if (IS_ERR(rockchip->vpcie3v3)) {
+ if (PTR_ERR(rockchip->vpcie3v3) != -ENODEV)
+ return dev_err_probe(dev, PTR_ERR(rockchip->vpcie3v3),
+ "failed to get vpcie3v3 regulator\n");
+ rockchip->vpcie3v3 = NULL;
+ } else {
+ ret = regulator_enable(rockchip->vpcie3v3);
+ if (ret) {
+ dev_err(dev, "failed to enable vpcie3v3 regulator\n");
+ return ret;
+ }
+ }
+
+ ret = rockchip_pcie_phy_init(rockchip);
+ if (ret)
+ goto disable_regulator;
+
+ ret = reset_control_deassert(rockchip->rst);
+ if (ret)
+ goto deinit_phy;
+
+ ret = rockchip_pcie_clk_init(rockchip);
+ if (ret)
+ goto deinit_phy;
+
+ ret = dw_pcie_host_init(pp);
+ if (!ret)
+ return 0;
+
+ clk_bulk_disable_unprepare(rockchip->clk_cnt, rockchip->clks);
+deinit_phy:
+ rockchip_pcie_phy_deinit(rockchip);
+disable_regulator:
+ if (rockchip->vpcie3v3)
+ regulator_disable(rockchip->vpcie3v3);
+
+ return ret;
+}
+
+static const struct of_device_id rockchip_pcie_of_match[] = {
+ { .compatible = "rockchip,rk3568-pcie", },
+ {},
+};
+
+static struct platform_driver rockchip_pcie_driver = {
+ .driver = {
+ .name = "rockchip-dw-pcie",
+ .of_match_table = rockchip_pcie_of_match,
+ .suppress_bind_attrs = true,
+ },
+ .probe = rockchip_pcie_probe,
+};
+builtin_platform_driver(rockchip_pcie_driver);