PCI: kirin: Add HiSilicon Kirin SoC PCIe controller driver

Hisilicon PCIe driver shares the common functions for PCIe dw-host.

The poweron functions are developed on hi3660 SoC, while other functions
are common for Kirin series SoCs.

Low power mode (L1 sub-state and Suspend/Resume), hotplug and MSI feature
are not supported currently.
Signed-off-by: Xiaowei Song <songxiaowei@hisilicon.com>
[bhelgaas: fold in MAINTAINERS update from
http://lkml.kernel.org/r/20170704021516.96575-1-songxiaowei@hisilicon.com]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Jingoo Han <jingoohan1@gmail.com>
Cc: Guodong Xu <guodong.xu@linaro.org>

MAINTAINERS

@@ -9933,6 +9933,14 @@ S:	Maintained
 F:	Documentation/devicetree/bindings/pci/hisilicon-pcie.txt
 F:	drivers/pci/dwc/pcie-hisi.c
 
+PCIE DRIVER FOR HISILICON KIRIN
+M:	Xiaowei Song <songxiaowei@hisilicon.com>
+M:	Binghui Wang <wangbinghui@hisilicon.com>
+L:	linux-pci@vger.kernel.org
+S:	Maintained
+F:	Documentation/devicetree/bindings/pci/pcie-kirin.txt
+F:	drivers/pci/dwc/pcie-kirin.c
+
 PCIE DRIVER FOR ROCKCHIP
 M:	Shawn Lin <shawn.lin@rock-chips.com>
 M:	Wenrui Li <wenrui.li@rock-chips.com>

drivers/pci/dwc/Kconfig

@@ -158,4 +158,14 @@ config PCIE_ARTPEC6
 	  Say Y here to enable PCIe controller support on Axis ARTPEC-6
 	  SoCs.  This PCIe controller uses the DesignWare core.
 
+config PCIE_KIRIN
+	depends on OF && ARM64
+	bool "HiSilicon Kirin series SoCs PCIe controllers"
+	depends on PCI
+	select PCIEPORTBUS
+	select PCIE_DW_HOST
+	help
+	  Say Y here if you want PCIe controller support
+	  on HiSilicon Kirin series SoCs.
+
 endmenu

drivers/pci/dwc/Makefile

@@ -13,6 +13,7 @@ obj-$(CONFIG_PCI_LAYERSCAPE) += pci-layerscape.o
 obj-$(CONFIG_PCIE_QCOM) += pcie-qcom.o
 obj-$(CONFIG_PCIE_ARMADA_8K) += pcie-armada8k.o
 obj-$(CONFIG_PCIE_ARTPEC6) += pcie-artpec6.o
+obj-$(CONFIG_PCIE_KIRIN) += pcie-kirin.o
 
 # The following drivers are for devices that use the generic ACPI
 # pci_root.c driver but don't support standard ECAM config access.

drivers/pci/dwc/pcie-kirin.c

+/*
+ * PCIe host controller driver for Kirin Phone SoCs
+ *
+ * Copyright (C) 2017 Hilisicon Electronics Co., Ltd.
+ *		http://www.huawei.com
+ *
+ * Author: Xiaowei Song <songxiaowei@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 <asm/compiler.h>
+#include <linux/compiler.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/gpio.h>
+#include <linux/interrupt.h>
+#include <linux/mfd/syscon.h>
+#include <linux/of_address.h>
+#include <linux/of_gpio.h>
+#include <linux/of_pci.h>
+#include <linux/pci.h>
+#include <linux/pci_regs.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/resource.h>
+#include <linux/types.h>
+#include "pcie-designware.h"
+
+#define to_kirin_pcie(x) dev_get_drvdata((x)->dev)
+
+#define REF_CLK_FREQ			100000000
+
+/* PCIe ELBI registers */
+#define SOC_PCIECTRL_CTRL0_ADDR		0x000
+#define SOC_PCIECTRL_CTRL1_ADDR		0x004
+#define SOC_PCIEPHY_CTRL2_ADDR		0x008
+#define SOC_PCIEPHY_CTRL3_ADDR		0x00c
+#define PCIE_ELBI_SLV_DBI_ENABLE	(0x1 << 21)
+
+/* info located in APB */
+#define PCIE_APP_LTSSM_ENABLE	0x01c
+#define PCIE_APB_PHY_CTRL0	0x0
+#define PCIE_APB_PHY_CTRL1	0x4
+#define PCIE_APB_PHY_STATUS0	0x400
+#define PCIE_LINKUP_ENABLE	(0x8020)
+#define PCIE_LTSSM_ENABLE_BIT	(0x1 << 11)
+#define PIPE_CLK_STABLE		(0x1 << 19)
+#define PHY_REF_PAD_BIT		(0x1 << 8)
+#define PHY_PWR_DOWN_BIT	(0x1 << 22)
+#define PHY_RST_ACK_BIT		(0x1 << 16)
+
+/* info located in sysctrl */
+#define SCTRL_PCIE_CMOS_OFFSET	0x60
+#define SCTRL_PCIE_CMOS_BIT	0x10
+#define SCTRL_PCIE_ISO_OFFSET	0x44
+#define SCTRL_PCIE_ISO_BIT	0x30
+#define SCTRL_PCIE_HPCLK_OFFSET	0x190
+#define SCTRL_PCIE_HPCLK_BIT	0x184000
+#define SCTRL_PCIE_OE_OFFSET	0x14a
+#define PCIE_DEBOUNCE_PARAM	0xF0F400
+#define PCIE_OE_BYPASS		(0x3 << 28)
+
+/* peri_crg ctrl */
+#define CRGCTRL_PCIE_ASSERT_OFFSET	0x88
+#define CRGCTRL_PCIE_ASSERT_BIT		0x8c000000
+
+/* Time for delay */
+#define REF_2_PERST_MIN		20000
+#define REF_2_PERST_MAX		25000
+#define PERST_2_ACCESS_MIN	10000
+#define PERST_2_ACCESS_MAX	12000
+#define LINK_WAIT_MIN		900
+#define LINK_WAIT_MAX		1000
+#define PIPE_CLK_WAIT_MIN	550
+#define PIPE_CLK_WAIT_MAX	600
+#define TIME_CMOS_MIN		100
+#define TIME_CMOS_MAX		105
+#define TIME_PHY_PD_MIN		10
+#define TIME_PHY_PD_MAX		11
+
+struct kirin_pcie {
+	struct dw_pcie	*pci;
+	void __iomem	*apb_base;
+	void __iomem	*phy_base;
+	struct regmap	*crgctrl;
+	struct regmap	*sysctrl;
+	struct clk	*apb_sys_clk;
+	struct clk	*apb_phy_clk;
+	struct clk	*phy_ref_clk;
+	struct clk	*pcie_aclk;
+	struct clk	*pcie_aux_clk;
+	int		gpio_id_reset;
+};
+
+/* Registers in PCIeCTRL */
+static inline void kirin_apb_ctrl_writel(struct kirin_pcie *kirin_pcie,
+					 u32 val, u32 reg)
+{
+	writel(val, kirin_pcie->apb_base + reg);
+}
+
+static inline u32 kirin_apb_ctrl_readl(struct kirin_pcie *kirin_pcie, u32 reg)
+{
+	return readl(kirin_pcie->apb_base + reg);
+}
+
+/* Registers in PCIePHY */
+static inline void kirin_apb_phy_writel(struct kirin_pcie *kirin_pcie,
+					u32 val, u32 reg)
+{
+	writel(val, kirin_pcie->phy_base + reg);
+}
+
+static inline u32 kirin_apb_phy_readl(struct kirin_pcie *kirin_pcie, u32 reg)
+{
+	return readl(kirin_pcie->phy_base + reg);
+}
+
+static long kirin_pcie_get_clk(struct kirin_pcie *kirin_pcie,
+			       struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+
+	kirin_pcie->phy_ref_clk = devm_clk_get(dev, "pcie_phy_ref");
+	if (IS_ERR(kirin_pcie->phy_ref_clk))
+		return PTR_ERR(kirin_pcie->phy_ref_clk);
+
+	kirin_pcie->pcie_aux_clk = devm_clk_get(dev, "pcie_aux");
+	if (IS_ERR(kirin_pcie->pcie_aux_clk))
+		return PTR_ERR(kirin_pcie->pcie_aux_clk);
+
+	kirin_pcie->apb_phy_clk = devm_clk_get(dev, "pcie_apb_phy");
+	if (IS_ERR(kirin_pcie->apb_phy_clk))
+		return PTR_ERR(kirin_pcie->apb_phy_clk);
+
+	kirin_pcie->apb_sys_clk = devm_clk_get(dev, "pcie_apb_sys");
+	if (IS_ERR(kirin_pcie->apb_sys_clk))
+		return PTR_ERR(kirin_pcie->apb_sys_clk);
+
+	kirin_pcie->pcie_aclk = devm_clk_get(dev, "pcie_aclk");
+	if (IS_ERR(kirin_pcie->pcie_aclk))
+		return PTR_ERR(kirin_pcie->pcie_aclk);
+
+	return 0;
+}
+
+static long kirin_pcie_get_resource(struct kirin_pcie *kirin_pcie,
+				    struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct resource *apb;
+	struct resource *phy;
+	struct resource *dbi;
+
+	apb = platform_get_resource_byname(pdev, IORESOURCE_MEM, "apb");
+	kirin_pcie->apb_base = devm_ioremap_resource(dev, apb);
+	if (IS_ERR(kirin_pcie->apb_base))
+		return PTR_ERR(kirin_pcie->apb_base);
+
+	phy = platform_get_resource_byname(pdev, IORESOURCE_MEM, "phy");
+	kirin_pcie->phy_base = devm_ioremap_resource(dev, phy);
+	if (IS_ERR(kirin_pcie->phy_base))
+		return PTR_ERR(kirin_pcie->phy_base);
+
+	dbi = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dbi");
+	kirin_pcie->pci->dbi_base = devm_ioremap_resource(dev, dbi);
+	if (IS_ERR(kirin_pcie->pci->dbi_base))
+		return PTR_ERR(kirin_pcie->pci->dbi_base);
+
+	kirin_pcie->crgctrl =
+		syscon_regmap_lookup_by_compatible("hisilicon,hi3660-crgctrl");
+	if (IS_ERR(kirin_pcie->crgctrl))
+		return PTR_ERR(kirin_pcie->crgctrl);
+
+	kirin_pcie->sysctrl =
+		syscon_regmap_lookup_by_compatible("hisilicon,hi3660-sctrl");
+	if (IS_ERR(kirin_pcie->sysctrl))
+		return PTR_ERR(kirin_pcie->sysctrl);
+
+	return 0;
+}
+
+static int kirin_pcie_phy_init(struct kirin_pcie *kirin_pcie)
+{
+	struct device *dev = kirin_pcie->pci->dev;
+	u32 reg_val;
+
+	reg_val = kirin_apb_phy_readl(kirin_pcie, PCIE_APB_PHY_CTRL1);
+	reg_val &= ~PHY_REF_PAD_BIT;
+	kirin_apb_phy_writel(kirin_pcie, reg_val, PCIE_APB_PHY_CTRL1);
+
+	reg_val = kirin_apb_phy_readl(kirin_pcie, PCIE_APB_PHY_CTRL0);
+	reg_val &= ~PHY_PWR_DOWN_BIT;
+	kirin_apb_phy_writel(kirin_pcie, reg_val, PCIE_APB_PHY_CTRL0);
+	usleep_range(TIME_PHY_PD_MIN, TIME_PHY_PD_MAX);
+
+	reg_val = kirin_apb_phy_readl(kirin_pcie, PCIE_APB_PHY_CTRL1);
+	reg_val &= ~PHY_RST_ACK_BIT;
+	kirin_apb_phy_writel(kirin_pcie, reg_val, PCIE_APB_PHY_CTRL1);
+
+	usleep_range(PIPE_CLK_WAIT_MIN, PIPE_CLK_WAIT_MAX);
+	reg_val = kirin_apb_phy_readl(kirin_pcie, PCIE_APB_PHY_STATUS0);
+	if (reg_val & PIPE_CLK_STABLE) {
+		dev_err(dev, "PIPE clk is not stable\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static void kirin_pcie_oe_enable(struct kirin_pcie *kirin_pcie)
+{
+	u32 val;
+
+	regmap_read(kirin_pcie->sysctrl, SCTRL_PCIE_OE_OFFSET, &val);
+	val |= PCIE_DEBOUNCE_PARAM;
+	val &= ~PCIE_OE_BYPASS;
+	regmap_write(kirin_pcie->sysctrl, SCTRL_PCIE_OE_OFFSET, val);
+}
+
+static int kirin_pcie_clk_ctrl(struct kirin_pcie *kirin_pcie, bool enable)
+{
+	int ret = 0;
+
+	if (!enable)
+		goto close_clk;
+
+	ret = clk_set_rate(kirin_pcie->phy_ref_clk, REF_CLK_FREQ);
+	if (ret)
+		return ret;
+
+	ret = clk_prepare_enable(kirin_pcie->phy_ref_clk);
+	if (ret)
+		return ret;
+
+	ret = clk_prepare_enable(kirin_pcie->apb_sys_clk);
+	if (ret)
+		goto apb_sys_fail;
+
+	ret = clk_prepare_enable(kirin_pcie->apb_phy_clk);
+	if (ret)
+		goto apb_phy_fail;
+
+	ret = clk_prepare_enable(kirin_pcie->pcie_aclk);
+	if (ret)
+		goto aclk_fail;
+
+	ret = clk_prepare_enable(kirin_pcie->pcie_aux_clk);
+	if (ret)
+		goto aux_clk_fail;
+
+	return 0;
+
+close_clk:
+	clk_disable_unprepare(kirin_pcie->pcie_aux_clk);
+aux_clk_fail:
+	clk_disable_unprepare(kirin_pcie->pcie_aclk);
+aclk_fail:
+	clk_disable_unprepare(kirin_pcie->apb_phy_clk);
+apb_phy_fail:
+	clk_disable_unprepare(kirin_pcie->apb_sys_clk);
+apb_sys_fail:
+	clk_disable_unprepare(kirin_pcie->phy_ref_clk);
+
+	return ret;
+}
+
+static int kirin_pcie_power_on(struct kirin_pcie *kirin_pcie)
+{
+	int ret;
+
+	/* Power supply for Host */
+	regmap_write(kirin_pcie->sysctrl,
+		     SCTRL_PCIE_CMOS_OFFSET, SCTRL_PCIE_CMOS_BIT);
+	usleep_range(TIME_CMOS_MIN, TIME_CMOS_MAX);
+	kirin_pcie_oe_enable(kirin_pcie);
+
+	ret = kirin_pcie_clk_ctrl(kirin_pcie, true);
+	if (ret)
+		return ret;
+
+	/* ISO disable, PCIeCtrl, PHY assert and clk gate clear */
+	regmap_write(kirin_pcie->sysctrl,
+		     SCTRL_PCIE_ISO_OFFSET, SCTRL_PCIE_ISO_BIT);
+	regmap_write(kirin_pcie->crgctrl,
+		     CRGCTRL_PCIE_ASSERT_OFFSET, CRGCTRL_PCIE_ASSERT_BIT);
+	regmap_write(kirin_pcie->sysctrl,
+		     SCTRL_PCIE_HPCLK_OFFSET, SCTRL_PCIE_HPCLK_BIT);
+
+	ret = kirin_pcie_phy_init(kirin_pcie);
+	if (ret)
+		goto close_clk;
+
+	/* perst assert Endpoint */
+	if (!gpio_request(kirin_pcie->gpio_id_reset, "pcie_perst")) {
+		usleep_range(REF_2_PERST_MIN, REF_2_PERST_MAX);
+		ret = gpio_direction_output(kirin_pcie->gpio_id_reset, 1);
+		if (ret)
+			goto close_clk;
+		usleep_range(PERST_2_ACCESS_MIN, PERST_2_ACCESS_MAX);
+
+		return 0;
+	}
+
+close_clk:
+	kirin_pcie_clk_ctrl(kirin_pcie, false);
+	return ret;
+}
+
+static void kirin_pcie_sideband_dbi_w_mode(struct kirin_pcie *kirin_pcie,
+					   bool on)
+{
+	u32 val;
+
+	val = kirin_apb_ctrl_readl(kirin_pcie, SOC_PCIECTRL_CTRL0_ADDR);
+	if (on)
+		val = val | PCIE_ELBI_SLV_DBI_ENABLE;
+	else
+		val = val & ~PCIE_ELBI_SLV_DBI_ENABLE;
+
+	kirin_apb_ctrl_writel(kirin_pcie, val, SOC_PCIECTRL_CTRL0_ADDR);
+}
+
+static void kirin_pcie_sideband_dbi_r_mode(struct kirin_pcie *kirin_pcie,
+					   bool on)
+{
+	u32 val;
+
+	val = kirin_apb_ctrl_readl(kirin_pcie, SOC_PCIECTRL_CTRL1_ADDR);
+	if (on)
+		val = val | PCIE_ELBI_SLV_DBI_ENABLE;
+	else
+		val = val & ~PCIE_ELBI_SLV_DBI_ENABLE;
+
+	kirin_apb_ctrl_writel(kirin_pcie, val, SOC_PCIECTRL_CTRL1_ADDR);
+}
+
+static int kirin_pcie_rd_own_conf(struct pcie_port *pp,
+				  int where, int size, u32 *val)
+{
+	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+	struct kirin_pcie *kirin_pcie = to_kirin_pcie(pci);
+	int ret;
+
+	kirin_pcie_sideband_dbi_r_mode(kirin_pcie, true);
+	ret = dw_pcie_read(pci->dbi_base + where, size, val);
+	kirin_pcie_sideband_dbi_r_mode(kirin_pcie, false);
+
+	return ret;
+}
+
+static int kirin_pcie_wr_own_conf(struct pcie_port *pp,
+				  int where, int size, u32 val)
+{
+	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+	struct kirin_pcie *kirin_pcie = to_kirin_pcie(pci);
+	int ret;
+
+	kirin_pcie_sideband_dbi_w_mode(kirin_pcie, true);
+	ret = dw_pcie_write(pci->dbi_base + where, size, val);
+	kirin_pcie_sideband_dbi_w_mode(kirin_pcie, false);
+
+	return ret;
+}
+
+static u32 kirin_pcie_read_dbi(struct dw_pcie *pci, void __iomem *base,
+			       u32 reg, size_t size)
+{
+	struct kirin_pcie *kirin_pcie = to_kirin_pcie(pci);
+	u32 ret;
+
+	kirin_pcie_sideband_dbi_r_mode(kirin_pcie, true);
+	dw_pcie_read(base + reg, size, &ret);
+	kirin_pcie_sideband_dbi_r_mode(kirin_pcie, false);
+
+	return ret;
+}
+
+static void kirin_pcie_write_dbi(struct dw_pcie *pci, void __iomem *base,
+				 u32 reg, size_t size, u32 val)
+{
+	struct kirin_pcie *kirin_pcie = to_kirin_pcie(pci);
+
+	kirin_pcie_sideband_dbi_w_mode(kirin_pcie, true);
+	dw_pcie_write(base + reg, size, val);
+	kirin_pcie_sideband_dbi_w_mode(kirin_pcie, false);
+}
+
+static int kirin_pcie_link_up(struct dw_pcie *pci)
+{
+	struct kirin_pcie *kirin_pcie = to_kirin_pcie(pci);
+	u32 val = kirin_apb_ctrl_readl(kirin_pcie, PCIE_APB_PHY_STATUS0);
+
+	if ((val & PCIE_LINKUP_ENABLE) == PCIE_LINKUP_ENABLE)
+		return 1;
+
+	return 0;
+}
+
+static int kirin_pcie_establish_link(struct pcie_port *pp)
+{
+	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+	struct kirin_pcie *kirin_pcie = to_kirin_pcie(pci);
+	struct device *dev = kirin_pcie->pci->dev;
+	int count = 0;
+
+	if (kirin_pcie_link_up(pci))
+		return 0;
+
+	dw_pcie_setup_rc(pp);
+
+	/* assert LTSSM enable */
+	kirin_apb_ctrl_writel(kirin_pcie, PCIE_LTSSM_ENABLE_BIT,
+			      PCIE_APP_LTSSM_ENABLE);
+
+	/* check if the link is up or not */
+	while (!kirin_pcie_link_up(pci)) {
+		usleep_range(LINK_WAIT_MIN, LINK_WAIT_MAX);
+		count++;
+		if (count == 1000) {
+			dev_err(dev, "Link Fail\n");
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+static void kirin_pcie_host_init(struct pcie_port *pp)
+{
+	kirin_pcie_establish_link(pp);
+}
+
+static struct dw_pcie_ops kirin_dw_pcie_ops = {
+	.read_dbi = kirin_pcie_read_dbi,
+	.write_dbi = kirin_pcie_write_dbi,
+	.link_up = kirin_pcie_link_up,
+};
+
+static struct dw_pcie_host_ops kirin_pcie_host_ops = {
+	.rd_own_conf = kirin_pcie_rd_own_conf,
+	.wr_own_conf = kirin_pcie_wr_own_conf,
+	.host_init = kirin_pcie_host_init,
+};
+
+static int __init kirin_add_pcie_port(struct dw_pcie *pci,
+				      struct platform_device *pdev)
+{
+	pci->pp.ops = &kirin_pcie_host_ops;
+
+	return dw_pcie_host_init(&pci->pp);
+}
+
+static int kirin_pcie_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct kirin_pcie *kirin_pcie;
+	struct dw_pcie *pci;
+	int ret;
+
+	if (!dev->of_node) {
+		dev_err(dev, "NULL node\n");
+		return -EINVAL;
+	}
+
+	kirin_pcie = devm_kzalloc(dev, sizeof(struct kirin_pcie), GFP_KERNEL);
+	if (!kirin_pcie)
+		return -ENOMEM;
+
+	pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL);
+	if (!pci)
+		return -ENOMEM;
+
+	pci->dev = dev;
+	pci->ops = &kirin_dw_pcie_ops;
+	kirin_pcie->pci = pci;
+
+	ret = kirin_pcie_get_clk(kirin_pcie, pdev);
+	if (ret)
+		return ret;
+
+	ret = kirin_pcie_get_resource(kirin_pcie, pdev);
+	if (ret)
+		return ret;
+
+	kirin_pcie->gpio_id_reset = of_get_named_gpio(dev->of_node,
+						      "reset-gpio", 0);
+	if (kirin_pcie->gpio_id_reset < 0)
+		return -ENODEV;
+
+	ret = kirin_pcie_power_on(kirin_pcie);
+	if (ret)
+		return ret;
+
+	platform_set_drvdata(pdev, kirin_pcie);
+
+	return kirin_add_pcie_port(pci, pdev);
+}
+
+static const struct of_device_id kirin_pcie_match[] = {
+	{ .compatible = "hisilicon,kirin960-pcie" },
+	{},
+};
+
+struct platform_driver kirin_pcie_driver = {
+	.probe			= kirin_pcie_probe,
+	.driver			= {
+		.name			= "kirin-pcie",
+		.of_match_table = kirin_pcie_match,
+		.suppress_bind_attrs = true,
+	},
+};
+builtin_platform_driver(kirin_pcie_driver);