PCI: hisi: Add HiSilicon STB SoC PCIe controller driver

Add a HiSilicon STB SoC PCIe controller driver.  This controller is based
on the DesignWare PCIe core.

Signed-off-by: Jianguo Sun <sunjianguo1@huawei.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

1 files changed, 470 insertions, 0 deletions

diff --git a/drivers/pci/dwc/pcie-histb.c b/drivers/pci/dwc/pcie-histb.c
new file mode 100644
index 000000000000..33b01b734d7d
--- /dev/null
+++ b/drivers/pci/dwc/pcie-histb.c
@@ -0,0 +1,470 @@
+/*
+ * PCIe host controller driver for HiSilicon STB SoCs
+ *
+ * Copyright (C) 2016-2017 HiSilicon Co., Ltd. http://www.hisilicon.com
+ *
+ * Authors: Ruqiang Ju <juruqiang@hisilicon.com>
+ *          Jianguo Sun <sunjianguo1@huawei.com>
+ *
+ * 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/clk.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+#include <linux/pci.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+#include <linux/resource.h>
+#include <linux/reset.h>
+
+#include "pcie-designware.h"
+
+#define to_histb_pcie(x)	dev_get_drvdata((x)->dev)
+
+#define PCIE_SYS_CTRL0			0x0000
+#define PCIE_SYS_CTRL1			0x0004
+#define PCIE_SYS_CTRL7			0x001C
+#define PCIE_SYS_CTRL13			0x0034
+#define PCIE_SYS_CTRL15			0x003C
+#define PCIE_SYS_CTRL16			0x0040
+#define PCIE_SYS_CTRL17			0x0044
+
+#define PCIE_SYS_STAT0			0x0100
+#define PCIE_SYS_STAT4			0x0110
+
+#define PCIE_RDLH_LINK_UP		BIT(5)
+#define PCIE_XMLH_LINK_UP		BIT(15)
+#define PCIE_ELBI_SLV_DBI_ENABLE	BIT(21)
+#define PCIE_APP_LTSSM_ENABLE		BIT(11)
+
+#define PCIE_DEVICE_TYPE_MASK		GENMASK(31, 28)
+#define PCIE_WM_EP			0
+#define PCIE_WM_LEGACY			BIT(1)
+#define PCIE_WM_RC			BIT(30)
+
+#define PCIE_LTSSM_STATE_MASK		GENMASK(5, 0)
+#define PCIE_LTSSM_STATE_ACTIVE		0x11
+
+struct histb_pcie {
+	struct dw_pcie *pci;
+	struct clk *aux_clk;
+	struct clk *pipe_clk;
+	struct clk *sys_clk;
+	struct clk *bus_clk;
+	struct phy *phy;
+	struct reset_control *soft_reset;
+	struct reset_control *sys_reset;
+	struct reset_control *bus_reset;
+	void __iomem *ctrl;
+	int reset_gpio;
+};
+
+static u32 histb_pcie_readl(struct histb_pcie *histb_pcie, u32 reg)
+{
+	return readl(histb_pcie->ctrl + reg);
+}
+
+static void histb_pcie_writel(struct histb_pcie *histb_pcie, u32 reg, u32 val)
+{
+	writel(val, histb_pcie->ctrl + reg);
+}
+
+static void histb_pcie_dbi_w_mode(struct pcie_port *pp, bool enable)
+{
+	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+	struct histb_pcie *hipcie = to_histb_pcie(pci);
+	u32 val;
+
+	val = histb_pcie_readl(hipcie, PCIE_SYS_CTRL0);
+	if (enable)
+		val |= PCIE_ELBI_SLV_DBI_ENABLE;
+	else
+		val &= ~PCIE_ELBI_SLV_DBI_ENABLE;
+	histb_pcie_writel(hipcie, PCIE_SYS_CTRL0, val);
+}
+
+static void histb_pcie_dbi_r_mode(struct pcie_port *pp, bool enable)
+{
+	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+	struct histb_pcie *hipcie = to_histb_pcie(pci);
+	u32 val;
+
+	val = histb_pcie_readl(hipcie, PCIE_SYS_CTRL1);
+	if (enable)
+		val |= PCIE_ELBI_SLV_DBI_ENABLE;
+	else
+		val &= ~PCIE_ELBI_SLV_DBI_ENABLE;
+	histb_pcie_writel(hipcie, PCIE_SYS_CTRL1, val);
+}
+
+static u32 histb_pcie_read_dbi(struct dw_pcie *pci, void __iomem *base,
+			       u32 reg, size_t size)
+{
+	u32 val;
+
+	histb_pcie_dbi_r_mode(&pci->pp, true);
+	dw_pcie_read(base + reg, size, &val);
+	histb_pcie_dbi_r_mode(&pci->pp, false);
+
+	return val;
+}
+
+static void histb_pcie_write_dbi(struct dw_pcie *pci, void __iomem *base,
+				 u32 reg, size_t size, u32 val)
+{
+	histb_pcie_dbi_w_mode(&pci->pp, true);
+	dw_pcie_write(base + reg, size, val);
+	histb_pcie_dbi_w_mode(&pci->pp, false);
+}
+
+static int histb_pcie_rd_own_conf(struct pcie_port *pp, int where,
+				  int size, u32 *val)
+{
+	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+	int ret;
+
+	histb_pcie_dbi_r_mode(pp, true);
+	ret = dw_pcie_read(pci->dbi_base + where, size, val);
+	histb_pcie_dbi_r_mode(pp, false);
+
+	return ret;
+}
+
+static int histb_pcie_wr_own_conf(struct pcie_port *pp, int where,
+				  int size, u32 val)
+{
+	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+	int ret;
+
+	histb_pcie_dbi_w_mode(pp, true);
+	ret = dw_pcie_write(pci->dbi_base + where, size, val);
+	histb_pcie_dbi_w_mode(pp, false);
+
+	return ret;
+}
+
+static int histb_pcie_link_up(struct dw_pcie *pci)
+{
+	struct histb_pcie *hipcie = to_histb_pcie(pci);
+	u32 regval;
+	u32 status;
+
+	regval = histb_pcie_readl(hipcie, PCIE_SYS_STAT0);
+	status = histb_pcie_readl(hipcie, PCIE_SYS_STAT4);
+	status &= PCIE_LTSSM_STATE_MASK;
+	if ((regval & PCIE_XMLH_LINK_UP) && (regval & PCIE_RDLH_LINK_UP) &&
+	    (status == PCIE_LTSSM_STATE_ACTIVE))
+		return 1;
+
+	return 0;
+}
+
+static int histb_pcie_establish_link(struct pcie_port *pp)
+{
+	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+	struct histb_pcie *hipcie = to_histb_pcie(pci);
+	u32 regval;
+
+	if (dw_pcie_link_up(pci)) {
+		dev_info(pci->dev, "Link already up\n");
+		return 0;
+	}
+
+	/* PCIe RC work mode */
+	regval = histb_pcie_readl(hipcie, PCIE_SYS_CTRL0);
+	regval &= ~PCIE_DEVICE_TYPE_MASK;
+	regval |= PCIE_WM_RC;
+	histb_pcie_writel(hipcie, PCIE_SYS_CTRL0, regval);
+
+	/* setup root complex */
+	dw_pcie_setup_rc(pp);
+
+	/* assert LTSSM enable */
+	regval = histb_pcie_readl(hipcie, PCIE_SYS_CTRL7);
+	regval |= PCIE_APP_LTSSM_ENABLE;
+	histb_pcie_writel(hipcie, PCIE_SYS_CTRL7, regval);
+
+	return dw_pcie_wait_for_link(pci);
+}
+
+static int histb_pcie_host_init(struct pcie_port *pp)
+{
+	histb_pcie_establish_link(pp);
+
+	if (IS_ENABLED(CONFIG_PCI_MSI))
+		dw_pcie_msi_init(pp);
+
+	return 0;
+}
+
+static struct dw_pcie_host_ops histb_pcie_host_ops = {
+	.rd_own_conf = histb_pcie_rd_own_conf,
+	.wr_own_conf = histb_pcie_wr_own_conf,
+	.host_init = histb_pcie_host_init,
+};
+
+static irqreturn_t histb_pcie_msi_irq_handler(int irq, void *arg)
+{
+	struct pcie_port *pp = arg;
+
+	return dw_handle_msi_irq(pp);
+}
+
+static void histb_pcie_host_disable(struct histb_pcie *hipcie)
+{
+	reset_control_assert(hipcie->soft_reset);
+	reset_control_assert(hipcie->sys_reset);
+	reset_control_assert(hipcie->bus_reset);
+
+	clk_disable_unprepare(hipcie->aux_clk);
+	clk_disable_unprepare(hipcie->pipe_clk);
+	clk_disable_unprepare(hipcie->sys_clk);
+	clk_disable_unprepare(hipcie->bus_clk);
+
+	if (gpio_is_valid(hipcie->reset_gpio))
+		gpio_set_value_cansleep(hipcie->reset_gpio, 0);
+}
+
+static int histb_pcie_host_enable(struct pcie_port *pp)
+{
+	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+	struct histb_pcie *hipcie = to_histb_pcie(pci);
+	struct device *dev = pci->dev;
+	int ret;
+
+	/* power on PCIe device if have */
+	if (gpio_is_valid(hipcie->reset_gpio))
+		gpio_set_value_cansleep(hipcie->reset_gpio, 1);
+
+	ret = clk_prepare_enable(hipcie->bus_clk);
+	if (ret) {
+		dev_err(dev, "cannot prepare/enable bus clk\n");
+		goto err_bus_clk;
+	}
+
+	ret = clk_prepare_enable(hipcie->sys_clk);
+	if (ret) {
+		dev_err(dev, "cannot prepare/enable sys clk\n");
+		goto err_sys_clk;
+	}
+
+	ret = clk_prepare_enable(hipcie->pipe_clk);
+	if (ret) {
+		dev_err(dev, "cannot prepare/enable pipe clk\n");
+		goto err_pipe_clk;
+	}
+
+	ret = clk_prepare_enable(hipcie->aux_clk);
+	if (ret) {
+		dev_err(dev, "cannot prepare/enable aux clk\n");
+		goto err_aux_clk;
+	}
+
+	reset_control_assert(hipcie->soft_reset);
+	reset_control_deassert(hipcie->soft_reset);
+
+	reset_control_assert(hipcie->sys_reset);
+	reset_control_deassert(hipcie->sys_reset);
+
+	reset_control_assert(hipcie->bus_reset);
+	reset_control_deassert(hipcie->bus_reset);
+
+	return 0;
+
+err_aux_clk:
+	clk_disable_unprepare(hipcie->aux_clk);
+err_pipe_clk:
+	clk_disable_unprepare(hipcie->pipe_clk);
+err_sys_clk:
+	clk_disable_unprepare(hipcie->sys_clk);
+err_bus_clk:
+	clk_disable_unprepare(hipcie->bus_clk);
+
+	return ret;
+}
+
+static const struct dw_pcie_ops dw_pcie_ops = {
+	.read_dbi = histb_pcie_read_dbi,
+	.write_dbi = histb_pcie_write_dbi,
+	.link_up = histb_pcie_link_up,
+};
+
+static int histb_pcie_probe(struct platform_device *pdev)
+{
+	struct histb_pcie *hipcie;
+	struct dw_pcie *pci;
+	struct pcie_port *pp;
+	struct resource *res;
+	struct device_node *np = pdev->dev.of_node;
+	struct device *dev = &pdev->dev;
+	enum of_gpio_flags of_flags;
+	unsigned long flag = GPIOF_DIR_OUT;
+	int ret;
+
+	hipcie = devm_kzalloc(dev, sizeof(*hipcie), GFP_KERNEL);
+	if (!hipcie)
+		return -ENOMEM;
+
+	pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL);
+	if (!pci)
+		return -ENOMEM;
+
+	hipcie->pci = pci;
+	pp = &pci->pp;
+	pci->dev = dev;
+	pci->ops = &dw_pcie_ops;
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "control");
+	hipcie->ctrl = devm_ioremap_resource(dev, res);
+	if (IS_ERR(hipcie->ctrl)) {
+		dev_err(dev, "cannot get control reg base\n");
+		return PTR_ERR(hipcie->ctrl);
+	}
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "rc-dbi");
+	pci->dbi_base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(pci->dbi_base)) {
+		dev_err(dev, "cannot get rc-dbi base\n");
+		return PTR_ERR(pci->dbi_base);
+	}
+
+	hipcie->reset_gpio = of_get_named_gpio_flags(np,
+				"reset-gpios", 0, &of_flags);
+	if (of_flags & OF_GPIO_ACTIVE_LOW)
+		flag |= GPIOF_ACTIVE_LOW;
+	if (gpio_is_valid(hipcie->reset_gpio)) {
+		ret = devm_gpio_request_one(dev, hipcie->reset_gpio,
+				flag, "PCIe device power control");
+		if (ret) {
+			dev_err(dev, "unable to request gpio\n");
+			return ret;
+		}
+	}
+
+	hipcie->aux_clk = devm_clk_get(dev, "aux");
+	if (IS_ERR(hipcie->aux_clk)) {
+		dev_err(dev, "Failed to get PCIe aux clk\n");
+		return PTR_ERR(hipcie->aux_clk);
+	}
+
+	hipcie->pipe_clk = devm_clk_get(dev, "pipe");
+	if (IS_ERR(hipcie->pipe_clk)) {
+		dev_err(dev, "Failed to get PCIe pipe clk\n");
+		return PTR_ERR(hipcie->pipe_clk);
+	}
+
+	hipcie->sys_clk = devm_clk_get(dev, "sys");
+	if (IS_ERR(hipcie->sys_clk)) {
+		dev_err(dev, "Failed to get PCIEe sys clk\n");
+		return PTR_ERR(hipcie->sys_clk);
+	}
+
+	hipcie->bus_clk = devm_clk_get(dev, "bus");
+	if (IS_ERR(hipcie->bus_clk)) {
+		dev_err(dev, "Failed to get PCIe bus clk\n");
+		return PTR_ERR(hipcie->bus_clk);
+	}
+
+	hipcie->soft_reset = devm_reset_control_get(dev, "soft");
+	if (IS_ERR(hipcie->soft_reset)) {
+		dev_err(dev, "couldn't get soft reset\n");
+		return PTR_ERR(hipcie->soft_reset);
+	}
+
+	hipcie->sys_reset = devm_reset_control_get(dev, "sys");
+	if (IS_ERR(hipcie->sys_reset)) {
+		dev_err(dev, "couldn't get sys reset\n");
+		return PTR_ERR(hipcie->sys_reset);
+	}
+
+	hipcie->bus_reset = devm_reset_control_get(dev, "bus");
+	if (IS_ERR(hipcie->bus_reset)) {
+		dev_err(dev, "couldn't get bus reset\n");
+		return PTR_ERR(hipcie->bus_reset);
+	}
+
+	if (IS_ENABLED(CONFIG_PCI_MSI)) {
+		pp->msi_irq = platform_get_irq_byname(pdev, "msi");
+		if (pp->msi_irq < 0) {
+			dev_err(dev, "Failed to get MSI IRQ\n");
+			return pp->msi_irq;
+		}
+
+		ret = devm_request_irq(dev, pp->msi_irq,
+				       histb_pcie_msi_irq_handler,
+				       IRQF_SHARED, "histb-pcie-msi", pp);
+		if (ret) {
+			dev_err(dev, "cannot request MSI IRQ\n");
+			return ret;
+		}
+	}
+
+	hipcie->phy = devm_phy_get(dev, "phy");
+	if (IS_ERR(hipcie->phy)) {
+		dev_info(dev, "no pcie-phy found\n");
+		hipcie->phy = NULL;
+		/* fall through here!
+		 * if no pcie-phy found, phy init
+		 * should be done under boot!
+		 */
+	} else {
+		phy_init(hipcie->phy);
+	}
+
+	pp->root_bus_nr = -1;
+	pp->ops = &histb_pcie_host_ops;
+
+	platform_set_drvdata(pdev, hipcie);
+
+	ret = histb_pcie_host_enable(pp);
+	if (ret) {
+		dev_err(dev, "failed to enable host\n");
+		return ret;
+	}
+
+	ret = dw_pcie_host_init(pp);
+	if (ret) {
+		dev_err(dev, "failed to initialize host\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static int histb_pcie_remove(struct platform_device *pdev)
+{
+	struct histb_pcie *hipcie = platform_get_drvdata(pdev);
+
+	histb_pcie_host_disable(hipcie);
+
+	if (hipcie->phy)
+		phy_exit(hipcie->phy);
+
+	return 0;
+}
+
+static const struct of_device_id histb_pcie_of_match[] = {
+	{ .compatible = "hisilicon,hi3798cv200-pcie", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, histb_pcie_of_match);
+
+static struct platform_driver histb_pcie_platform_driver = {
+	.probe	= histb_pcie_probe,
+	.remove	= histb_pcie_remove,
+	.driver = {
+		.name = "histb-pcie",
+		.of_match_table = histb_pcie_of_match,
+	},
+};
+module_platform_driver(histb_pcie_platform_driver);
+
+MODULE_DESCRIPTION("HiSilicon STB PCIe host controller driver");
+MODULE_LICENSE("GPL v2");