[PATCH 5/6] PCI: rockchip: add DesignWare based PCIe controller

[Shawn Lin <shawn.lin@rock-chips.com>]

From: Simon Xue <xxm@rock-chips.com>

Signed-off-by: Simon Xue <xxm@rock-chips.com>
Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
---

 drivers/pci/controller/dwc/Kconfig            |   9 +
 drivers/pci/controller/dwc/Makefile           |   1 +
 drivers/pci/controller/dwc/pcie-dw-rockchip.c | 441 ++++++++++++++++++++++++++
 3 files changed, 451 insertions(+)
 create mode 100644 drivers/pci/controller/dwc/pcie-dw-rockchip.c

diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig
index 0830dfc..9160264 100644
--- a/drivers/pci/controller/dwc/Kconfig
+++ b/drivers/pci/controller/dwc/Kconfig
@@ -82,6 +82,15 @@ config PCIE_DW_PLAT_EP
 	  order to enable device-specific features PCI_DW_PLAT_EP must be
 	  selected.
 
+config PCIE_DW_ROCKCHIP
+	bool "Rockchip DesignWare PCIe controller"
+	select PCIE_DW
+	select PCIE_DW_HOST
+	depends on ARCH_ROCKCHIP
+	depends on OF
+	help
+	  Enables support for the DW PCIe controller in the Rockchip SoC.
+
 config PCI_EXYNOS
 	bool "Samsung Exynos PCIe controller"
 	depends on SOC_EXYNOS5440 || COMPILE_TEST
diff --git a/drivers/pci/controller/dwc/Makefile b/drivers/pci/controller/dwc/Makefile
index 8a637cf..cb4857f 100644
--- a/drivers/pci/controller/dwc/Makefile
+++ b/drivers/pci/controller/dwc/Makefile
@@ -19,6 +19,7 @@ obj-$(CONFIG_PCIE_HISI_STB) += pcie-histb.o
 obj-$(CONFIG_PCI_MESON) += pci-meson.o
 obj-$(CONFIG_PCIE_TEGRA194) += pcie-tegra194.o
 obj-$(CONFIG_PCIE_UNIPHIER) += pcie-uniphier.o
+obj-$(CONFIG_PCIE_DW_ROCKCHIP) += pcie-dw-rockchip.o
 
 # The following drivers are for devices that use the generic ACPI
 # pci_root.c driver but don't support standard ECAM config access.
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 0000000..dbc2667
--- /dev/null
+++ b/drivers/pci/controller/dwc/pcie-dw-rockchip.c
@@ -0,0 +1,441 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PCIe host controller driver for Rockchip SoCs
+ *
+ * Copyright (C) 2018 Rockchip Electronics Co., Ltd.
+ *		http://www.rock-chips.com
+ *
+ * Author: Simon Xue <xxm@rock-chips.com>
+ */
+
+#include <linux/clk.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/of_gpio.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.  This allows atomic updates
+ * of the register without locking.
+ */
+#define HIWORD_UPDATE(mask, val) (((mask) << 16) | (val))
+#define HIWORD_UPDATE_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_PHY_LINKUP			BIT(0)
+#define PCIE_DATA_LINKUP		BIT(1)
+#define PCIE_LTSSM_STATE_MASK		GENMASK(15, 10)
+#define PCIE_LTSSM_STATE_SHIFT		10
+#define PCIE_L0S_ENTRY			0x11
+#define PCIE_CLIENT_GENERAL_CONTROL	0x0
+#define PCIE_CLIENT_GENERAL_DEBUG	0x104
+#define SUB_PHY_MODE_PCIE_RC		0x0
+#define SUB_PHY_MODE_PCIE_EP		0x1
+
+
+struct reset_bulk_data	{
+	const char *id;
+	struct reset_control *rst;
+};
+
+struct rockchip_pcie {
+	struct dw_pcie			*pci;
+	void __iomem			*dbi_base;
+	void __iomem			*apb_base;
+	struct phy			*phy;
+	struct clk_bulk_data		*clks;
+	unsigned int			clk_cnt;
+	struct reset_bulk_data		*rsts;
+	struct gpio_desc		*rst_gpio;
+	struct pcie_port		pp;
+	struct regmap			*usb_pcie_grf;
+	enum dw_pcie_device_mode	mode;
+	int				sub_phy_mode;
+};
+
+struct rockchip_pcie_of_data {
+	enum dw_pcie_device_mode	mode;
+};
+
+static inline int rockchip_pcie_readl_apb(struct rockchip_pcie *rockchip,
+					  u32 reg)
+{
+	return readl(rockchip->apb_base + reg);
+}
+
+static inline void rockchip_pcie_writel_apb(struct rockchip_pcie *rockchip,
+					    u32 reg, u32 val)
+{
+	writel(val, rockchip->apb_base + reg);
+}
+
+static inline void rockchip_pcie_set_mode(struct rockchip_pcie *rockchip)
+{
+	rockchip_pcie_writel_apb(rockchip, PCIE_CLIENT_GENERAL_CONTROL,
+				 PCIE_CLIENT_RC_MODE);
+}
+
+static inline void rockchip_pcie_enable_ltssm(struct rockchip_pcie *rockchip)
+{
+	rockchip_pcie_writel_apb(rockchip, PCIE_CLIENT_GENERAL_CONTROL,
+				 PCIE_CLIENT_ENABLE_LTSSM);
+}
+
+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_GENERAL_DEBUG);
+	u32 state = (val & PCIE_LTSSM_STATE_MASK) >> PCIE_LTSSM_STATE_SHIFT;
+
+	if ((val & PCIE_PHY_LINKUP) &&
+	    (val & PCIE_DATA_LINKUP) &&
+	    state == PCIE_L0S_ENTRY)
+		return 1;
+
+	return 0;
+}
+
+static void rockchip_pcie_establish_link(struct dw_pcie *pci)
+{
+	struct rockchip_pcie *rockchip = to_rockchip_pcie(pci);
+
+	if (dw_pcie_link_up(pci)) {
+		dev_err(pci->dev, "link already up\n");
+		return;
+	}
+
+	/* Reset device */
+	gpiod_set_value_cansleep(rockchip->rst_gpio, 0);
+	msleep(100);
+	gpiod_set_value_cansleep(rockchip->rst_gpio, 1);
+
+	rockchip_pcie_enable_ltssm(rockchip);
+}
+
+static int rockchip_pcie_host_init(struct pcie_port *pp)
+{
+	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+
+	dw_pcie_setup_rc(pp);
+
+	rockchip_pcie_establish_link(pci);
+	dw_pcie_wait_for_link(pci);
+
+	return 0;
+}
+
+static const struct dw_pcie_host_ops rockchip_pcie_host_ops = {
+	.host_init = rockchip_pcie_host_init,
+};
+
+static int rk_add_pcie_port(struct rockchip_pcie *rockchip)
+{
+	int ret;
+	struct dw_pcie *pci = rockchip->pci;
+	struct pcie_port *pp = &pci->pp;
+	struct device *dev = pci->dev;
+
+	pp->ops = &rockchip_pcie_host_ops;
+
+	if (device_property_read_bool(dev, "msi-map"))
+		pp->msi_ext = 1;
+
+	rockchip_pcie_set_mode(rockchip);
+
+	ret = dw_pcie_host_init(pp);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static void rockchip_pcie_clk_deinit(struct rockchip_pcie *rockchip)
+{
+	clk_bulk_disable(rockchip->clk_cnt, rockchip->clks);
+	clk_bulk_unprepare(rockchip->clk_cnt, rockchip->clks);
+}
+
+static int rockchip_pcie_clk_init(struct rockchip_pcie *rockchip)
+{
+	struct device *dev = rockchip->pci->dev;
+	struct property *prop;
+	const char *name;
+	int i = 0, ret, count;
+
+	count = of_property_count_strings(dev->of_node, "clock-names");
+	if (count < 1)
+		return -ENODEV;
+
+	rockchip->clks = devm_kcalloc(dev, count,
+				     sizeof(struct clk_bulk_data),
+				     GFP_KERNEL);
+	if (!rockchip->clks)
+		return -ENOMEM;
+
+	rockchip->clk_cnt = count;
+
+	of_property_for_each_string(dev->of_node, "clock-names",
+				    prop, name) {
+		rockchip->clks[i].id = name;
+		if (!rockchip->clks[i].id)
+			return -ENOMEM;
+		i++;
+	}
+
+	ret = devm_clk_bulk_get(dev, count, rockchip->clks);
+	if (ret)
+		return ret;
+
+	ret = clk_bulk_prepare(count, rockchip->clks);
+	if (ret)
+		return ret;
+
+	ret = clk_bulk_enable(count, rockchip->clks);
+	if (ret) {
+		clk_bulk_unprepare(count, rockchip->clks);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int rockchip_pcie_resource_get(struct platform_device *pdev,
+				      struct rockchip_pcie *rockchip)
+{
+	struct resource *dbi_base;
+	struct resource *apb_base;
+
+	dbi_base = platform_get_resource_byname(pdev, IORESOURCE_MEM,
+						"pcie-dbi");
+	if (!dbi_base)
+		return -ENODEV;
+
+	rockchip->dbi_base = devm_ioremap_resource(&pdev->dev, dbi_base);
+	if (IS_ERR(rockchip->dbi_base))
+		return PTR_ERR(rockchip->dbi_base);
+
+	rockchip->pci->dbi_base = rockchip->dbi_base;
+
+	apb_base = platform_get_resource_byname(pdev, IORESOURCE_MEM,
+						"pcie-apb");
+	if (!apb_base)
+		return -ENODEV;
+
+	rockchip->apb_base = devm_ioremap_resource(&pdev->dev, apb_base);
+	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);
+
+	return 0;
+}
+
+static int rockchip_pcie_phy_init(struct rockchip_pcie *rockchip)
+{
+	int ret;
+	struct device *dev = rockchip->pci->dev;
+
+	rockchip->phy = devm_phy_get(dev, "pcie-phy");
+	if (IS_ERR(rockchip->phy)) {
+		if (PTR_ERR(rockchip->phy) != -EPROBE_DEFER)
+			dev_info(dev, "missing phy\n");
+		return PTR_ERR(rockchip->phy);
+	}
+
+	rockchip->sub_phy_mode = rockchip->mode == DW_PCIE_RC_TYPE ?
+			SUB_PHY_MODE_PCIE_RC : SUB_PHY_MODE_PCIE_EP;
+
+	ret = phy_set_mode_ext(rockchip->phy, PHY_MODE_PCIE,
+			       rockchip->sub_phy_mode);
+	if (ret)
+		return ret;
+
+	ret = phy_init(rockchip->phy);
+	if (ret < 0)
+		return ret;
+
+	phy_power_on(rockchip->phy);
+
+	return 0;
+}
+
+static int rockchip_pcie_reset_control_release(struct rockchip_pcie *rockchip)
+{
+	struct device *dev = rockchip->pci->dev;
+	struct property *prop;
+	const char *name;
+	int ret, count, i = 0;
+
+	count = of_property_count_strings(dev->of_node, "reset-names");
+	if (count < 1)
+		return -ENODEV;
+
+	rockchip->rsts = devm_kcalloc(dev, count,
+				     sizeof(struct reset_bulk_data),
+				     GFP_KERNEL);
+	if (!rockchip->rsts)
+		return -ENOMEM;
+
+	of_property_for_each_string(dev->of_node, "reset-names",
+				    prop, name) {
+		rockchip->rsts[i].id = name;
+		if (!rockchip->rsts[i].id)
+			return -ENOMEM;
+		i++;
+	}
+
+	for (i = 0; i < count; i++) {
+		rockchip->rsts[i].rst = devm_reset_control_get_exclusive(dev,
+						rockchip->rsts[i].id);
+		if (IS_ERR_OR_NULL(rockchip->rsts[i].rst)) {
+			dev_err(dev, "failed to get %s\n",
+				rockchip->clks[i].id);
+			return -PTR_ERR(rockchip->rsts[i].rst);
+		}
+	}
+
+	for (i = 0; i < count; i++) {
+		ret = reset_control_deassert(rockchip->rsts[i].rst);
+		if (ret) {
+			dev_err(dev, "failed to release %s\n",
+				rockchip->rsts[i].id);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static int rockchip_pcie_reset_grant_ctrl(struct rockchip_pcie *rockchip,
+					  bool enable)
+{
+	int ret;
+	u32 val = HIWORD_UPDATE(BIT(2), 0); /* Write mask bit */
+
+	if (enable)
+		val |= BIT(2);
+
+	ret = regmap_write(rockchip->usb_pcie_grf, 0x0, val);
+	return ret;
+}
+
+static const struct rockchip_pcie_of_data rockchip_rc_of_data = {
+	.mode = DW_PCIE_RC_TYPE,
+};
+
+static const struct of_device_id rockchip_pcie_of_match[] = {
+	{
+		.compatible = "rockchip,rk1808-pcie",
+		.data = &rockchip_rc_of_data,
+	},
+	{ /* sentinel */ },
+};
+
+static const struct dw_pcie_ops dw_pcie_ops = {
+	.link_up = rockchip_pcie_link_up,
+};
+
+static int rockchip_pcie_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct rockchip_pcie *rockchip;
+	struct dw_pcie *pci;
+	int ret;
+	const struct of_device_id *match;
+	const struct rockchip_pcie_of_data *data;
+	enum dw_pcie_device_mode mode;
+
+	match = of_match_device(rockchip_pcie_of_match, dev);
+	if (!match)
+		return -EINVAL;
+
+	data = (struct rockchip_pcie_of_data *)match->data;
+	mode = (enum dw_pcie_device_mode)data->mode;
+
+	rockchip = devm_kzalloc(dev, sizeof(*rockchip), GFP_KERNEL);
+	if (!rockchip)
+		return -ENOMEM;
+
+	pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL);
+	if (!pci)
+		return -ENOMEM;
+
+	pci->dev = dev;
+	pci->ops = &dw_pcie_ops;
+
+	rockchip->mode = mode;
+	rockchip->pci = pci;
+
+	ret = rockchip_pcie_resource_get(pdev, rockchip);
+	if (ret)
+		return ret;
+
+	ret = rockchip_pcie_phy_init(rockchip);
+	if (ret)
+		return ret;
+
+	ret = rockchip_pcie_reset_control_release(rockchip);
+	if (ret)
+		return ret;
+
+	rockchip->usb_pcie_grf =
+		syscon_regmap_lookup_by_phandle(dev->of_node,
+						"rockchip,usbpciegrf");
+	if (IS_ERR(rockchip->usb_pcie_grf))
+		return PTR_ERR(rockchip->usb_pcie_grf);
+
+	ret = rockchip_pcie_clk_init(rockchip);
+	if (ret)
+		return ret;
+
+	platform_set_drvdata(pdev, rockchip);
+
+	ret = rockchip_pcie_reset_grant_ctrl(rockchip, true);
+	if (ret)
+		goto deinit_clk;
+
+//	if (rockchip->mode == DW_PCIE_RC_TYPE)
+//		ret = rk_add_pcie_port(rockchip);
+	ret = rockchip->mode == DW_PCIE_RC_TYPE ?
+		rk_add_pcie_port(rockchip) : -EINVAL;
+
+	if (ret)
+		goto deinit_clk;
+
+	ret = rockchip_pcie_reset_grant_ctrl(rockchip, false);
+	if (ret)
+		goto deinit_clk;
+
+	return 0;
+
+deinit_clk:
+	rockchip_pcie_clk_deinit(rockchip);
+
+	return ret;
+}
+
+MODULE_DEVICE_TABLE(of, rockchip_pcie_of_match);
+
+static struct platform_driver rockchip_pcie_driver = {
+	.driver = {
+		.name	= "rk-pcie",
+		.of_match_table = rockchip_pcie_of_match,
+		.suppress_bind_attrs = true,
+	},
+	.probe = rockchip_pcie_probe,
+};
+
+builtin_platform_driver(rockchip_pcie_driver);
-- 
1.9.1