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From:   Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>
To:     Bjorn Helgaas <bhelgaas@google.com>,
        Rob Herring <robh+dt@kernel.org>,
        Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc:     linux-pci@vger.kernel.org,
        =?UTF-8?q?Krzysztof=20Wilczy=C5=84ski?= <kw@linux.com>,
        Kishon Vijay Abraham I <kishon@ti.com>,
        devicetree@vger.kernel.org, punit1.agrawal@toshiba.co.jp,
        yuji2.ishikawa@toshiba.co.jp, linux-arm-kernel@lists.infradead.org,
        linux-kernel@vger.kernel.org,
        Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>
Subject: [PATCH v6 2/3] PCI: visconti: Add Toshiba Visconti PCIe host controller driver
Date:   Wed, 11 Aug 2021 17:38:29 +0900
Message-Id: <20210811083830.784065-3-nobuhiro1.iwamatsu@toshiba.co.jp>
In-Reply-To: <20210811083830.784065-1-nobuhiro1.iwamatsu@toshiba.co.jp>
References: <20210811083830.784065-1-nobuhiro1.iwamatsu@toshiba.co.jp>
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Add support to PCIe RC controller on Toshiba Visconti ARM SoCs. PCIe
controller is based of Synopsys DesignWare PCIe core.

Signed-off-by: Yuji Ishikawa <yuji2.ishikawa@toshiba.co.jp>
Signed-off-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>

v5 -> v6:
  - Remove unnecessary commit log.
  - Fix split line of visconti_add_pcie_port()

v4 -> v5:
  - Remove PCIE_BUS_OFFSET
  - Change link_up confirmation function of visconti_pcie_link_up().
  - Move setting event mask before dw_pcie_link_up().
  - Move the contents of visconti_pcie_power_on() to visconti_pcie_host_init().
  - Remove code for link_gen.

v3 -> v4:
  - Change variable from pci_addr to cpu_addr in visconti_pcie_cpu_addr_fixup().
  - Change the calculation method of CPU addres from subtraction to mask, and
    add comment.
  - Drop dma_set_mask_and_coherent().
  - Drop set MAX_MSI_IRQS.
  - Drop dev_dbg for Link speed.
  - Use use the dev_err_probe() to handle the devm_clk_get() failed.
  - Changed the redundant clock name.

v2 -> v3:
  - Update subject.
  - Wrap description in 75 columns.
  - Change config name to PCIE_VISCONTI_HOST.
  - Update Kconfig text.
  - Drop blank lines.
  - Adjusted to 80 columns.
  - Drop inline from functions for register access.
  - Changed function name from visconti_pcie_check_link_status to
    visconti_pcie_link_up.
  - Update to using dw_pcie_host_init().
  - Reorder these in the order of use in visconti_pcie_establish_link.
  - Rewrite visconti_pcie_host_init() without dw_pcie_setup_rc().
  - Change function name from  visconti_device_turnon() to
    visconti_pcie_power_on().
  - Unify formats such as dev_err().
  - Drop error label in visconti_add_pcie_port().

v1 -> v2:
  - Fix typo in commit message.
  - Drop "depends on OF && HAS_IOMEM" from Kconfig.
  - Stop using the pointer of struct dw_pcie.
  - Use _relaxed variant.
  - Drop dw_pcie_wait_for_link.
  - Drop dbi resource processing.
  - Drop MSI IRQ initialization processing.
---
 drivers/pci/controller/dwc/Kconfig         |   9 +
 drivers/pci/controller/dwc/Makefile        |   1 +
 drivers/pci/controller/dwc/pcie-visconti.c | 333 +++++++++++++++++++++
 3 files changed, 343 insertions(+)
 create mode 100644 drivers/pci/controller/dwc/pcie-visconti.c

diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig
index 423d35872ce4..7c3dcb86fcad 100644
--- a/drivers/pci/controller/dwc/Kconfig
+++ b/drivers/pci/controller/dwc/Kconfig
@@ -286,6 +286,15 @@ config PCIE_TEGRA194_EP
 	  in order to enable device-specific features PCIE_TEGRA194_EP must be
 	  selected. This uses the DesignWare core.
 
+config PCIE_VISCONTI_HOST
+	bool "Toshiba Visconti PCIe controllers"
+	depends on ARCH_VISCONTI || COMPILE_TEST
+	depends on PCI_MSI_IRQ_DOMAIN
+	select PCIE_DW_HOST
+	help
+	  Say Y here if you want PCIe controller support on Toshiba Visconti SoC.
+	  This driver supports TMPV7708 SoC.
+
 config PCIE_UNIPHIER
 	bool "Socionext UniPhier PCIe host controllers"
 	depends on ARCH_UNIPHIER || COMPILE_TEST
diff --git a/drivers/pci/controller/dwc/Makefile b/drivers/pci/controller/dwc/Makefile
index eca805c1a023..0b569d54deb3 100644
--- a/drivers/pci/controller/dwc/Makefile
+++ b/drivers/pci/controller/dwc/Makefile
@@ -20,6 +20,7 @@ obj-$(CONFIG_PCIE_HISI_STB) += pcie-histb.o
 obj-$(CONFIG_PCI_MESON) += pci-meson.o
 obj-$(CONFIG_PCIE_UNIPHIER) += pcie-uniphier.o
 obj-$(CONFIG_PCIE_UNIPHIER_EP) += pcie-uniphier-ep.o
+obj-$(CONFIG_PCIE_VISCONTI_HOST) += pcie-visconti.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-visconti.c b/drivers/pci/controller/dwc/pcie-visconti.c
new file mode 100644
index 000000000000..c3fb87c5e7e1
--- /dev/null
+++ b/drivers/pci/controller/dwc/pcie-visconti.c
@@ -0,0 +1,333 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * DWC PCIe RC driver for Toshiba Visconti ARM SoC
+ *
+ * Copyright (C) 2021 Toshiba Electronic Device & Storage Corporation
+ * Copyright (C) 2021 TOSHIBA CORPORATION
+ *
+ * Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/gpio.h>
+#include <linux/interrupt.h>
+#include <linux/init.h>
+#include <linux/iopoll.h>
+#include <linux/kernel.h>
+#include <linux/of_platform.h>
+#include <linux/pci.h>
+#include <linux/platform_device.h>
+#include <linux/resource.h>
+#include <linux/types.h>
+
+#include "pcie-designware.h"
+#include "../../pci.h"
+
+struct visconti_pcie {
+	struct dw_pcie pci;
+	void __iomem *ulreg_base;
+	void __iomem *smu_base;
+	void __iomem *mpu_base;
+	struct clk *refclk;
+	struct clk *coreclk;
+	struct clk *auxclk;
+};
+
+#define PCIE_UL_REG_S_PCIE_MODE		0x00F4
+#define  PCIE_UL_REG_S_PCIE_MODE_EP	0x00
+#define  PCIE_UL_REG_S_PCIE_MODE_RC	0x04
+
+#define PCIE_UL_REG_S_PERSTN_CTRL	0x00F8
+#define  PCIE_UL_IOM_PCIE_PERSTN_I_EN	BIT(3)
+#define  PCIE_UL_DIRECT_PERSTN_EN	BIT(2)
+#define  PCIE_UL_PERSTN_OUT		BIT(1)
+#define  PCIE_UL_DIRECT_PERSTN		BIT(0)
+#define  PCIE_UL_REG_S_PERSTN_CTRL_INIT	(PCIE_UL_IOM_PCIE_PERSTN_I_EN | \
+					 PCIE_UL_DIRECT_PERSTN_EN | \
+					 PCIE_UL_DIRECT_PERSTN)
+
+#define PCIE_UL_REG_S_PHY_INIT_02	0x0104
+#define  PCIE_UL_PHY0_SRAM_EXT_LD_DONE	BIT(0)
+
+#define PCIE_UL_REG_S_PHY_INIT_03	0x0108
+#define  PCIE_UL_PHY0_SRAM_INIT_DONE	BIT(0)
+
+#define PCIE_UL_REG_S_INT_EVENT_MASK1	0x0138
+#define  PCIE_UL_CFG_PME_INT		BIT(0)
+#define  PCIE_UL_CFG_LINK_EQ_REQ_INT	BIT(1)
+#define  PCIE_UL_EDMA_INT0		BIT(2)
+#define  PCIE_UL_EDMA_INT1		BIT(3)
+#define  PCIE_UL_EDMA_INT2		BIT(4)
+#define  PCIE_UL_EDMA_INT3		BIT(5)
+#define  PCIE_UL_S_INT_EVENT_MASK1_ALL  (PCIE_UL_CFG_PME_INT | \
+					 PCIE_UL_CFG_LINK_EQ_REQ_INT | \
+					 PCIE_UL_EDMA_INT0 | \
+					 PCIE_UL_EDMA_INT1 | \
+					 PCIE_UL_EDMA_INT2 | \
+					 PCIE_UL_EDMA_INT3)
+
+#define PCIE_UL_REG_S_SB_MON		0x0198
+#define PCIE_UL_REG_S_SIG_MON		0x019C
+#define  PCIE_UL_CORE_RST_N_MON		BIT(0)
+
+#define PCIE_UL_REG_V_SII_DBG_00	0x0844
+#define PCIE_UL_REG_V_SII_GEN_CTRL_01	0x0860
+#define  PCIE_UL_APP_LTSSM_ENABLE	BIT(0)
+
+#define PCIE_UL_REG_V_PHY_ST_00		0x0864
+#define  PCIE_UL_SMLH_LINK_UP		BIT(0)
+
+#define PCIE_UL_REG_V_PHY_ST_02		0x0868
+#define  PCIE_UL_S_DETECT_ACT		0x01
+#define  PCIE_UL_S_L0			0x11
+
+#define PISMU_CKON_PCIE			0x0038
+#define  PISMU_CKON_PCIE_AUX_CLK	BIT(1)
+#define  PISMU_CKON_PCIE_MSTR_ACLK	BIT(0)
+
+#define PISMU_RSOFF_PCIE		0x0538
+#define  PISMU_RSOFF_PCIE_ULREG_RST_N	BIT(1)
+#define  PISMU_RSOFF_PCIE_PWR_UP_RST_N	BIT(0)
+
+#define PCIE_MPU_REG_MP_EN		0x0
+#define  MPU_MP_EN_DISABLE		BIT(0)
+
+/* Access registers in PCIe ulreg */
+static void visconti_ulreg_writel(struct visconti_pcie *pcie, u32 val, u32 reg)
+{
+	writel_relaxed(val, pcie->ulreg_base + reg);
+}
+
+static u32 visconti_ulreg_readl(struct visconti_pcie *pcie, u32 reg)
+{
+	return readl_relaxed(pcie->ulreg_base + reg);
+}
+
+/* Access registers in PCIe smu */
+static void visconti_smu_writel(struct visconti_pcie *pcie, u32 val, u32 reg)
+{
+	writel_relaxed(val, pcie->smu_base + reg);
+}
+
+/* Access registers in PCIe mpu */
+static void visconti_mpu_writel(struct visconti_pcie *pcie, u32 val, u32 reg)
+{
+	writel_relaxed(val, pcie->mpu_base + reg);
+}
+
+static u32 visconti_mpu_readl(struct visconti_pcie *pcie, u32 reg)
+{
+	return readl_relaxed(pcie->mpu_base + reg);
+}
+
+static int visconti_pcie_link_up(struct dw_pcie *pci)
+{
+	struct visconti_pcie *pcie = dev_get_drvdata(pci->dev);
+	void __iomem *addr = pcie->ulreg_base;
+	u32 val = readl_relaxed(addr + PCIE_UL_REG_V_PHY_ST_02);
+
+	return !!(val & PCIE_UL_S_L0);
+}
+
+static int visconti_pcie_start_link(struct dw_pcie *pci)
+{
+	struct visconti_pcie *pcie = dev_get_drvdata(pci->dev);
+	void __iomem *addr = pcie->ulreg_base;
+	u32 val;
+	int ret;
+
+	visconti_ulreg_writel(pcie, PCIE_UL_APP_LTSSM_ENABLE,
+			      PCIE_UL_REG_V_SII_GEN_CTRL_01);
+
+	ret = readl_relaxed_poll_timeout(addr + PCIE_UL_REG_V_PHY_ST_02,
+					 val, (val & PCIE_UL_S_L0),
+					 90000, 100000);
+	if (ret)
+		return ret;
+
+	visconti_ulreg_writel(pcie, PCIE_UL_S_INT_EVENT_MASK1_ALL,
+			      PCIE_UL_REG_S_INT_EVENT_MASK1);
+
+	if (dw_pcie_link_up(pci)) {
+		val = visconti_mpu_readl(pcie, PCIE_MPU_REG_MP_EN);
+		visconti_mpu_writel(pcie, val & ~MPU_MP_EN_DISABLE,
+				    PCIE_MPU_REG_MP_EN);
+	}
+
+	return 0;
+}
+
+static void visconti_pcie_stop_link(struct dw_pcie *pci)
+{
+	struct visconti_pcie *pcie = dev_get_drvdata(pci->dev);
+	u32 val;
+
+	val = visconti_ulreg_readl(pcie, PCIE_UL_REG_V_SII_GEN_CTRL_01);
+	val &= ~PCIE_UL_APP_LTSSM_ENABLE;
+	visconti_ulreg_writel(pcie, val, PCIE_UL_REG_V_SII_GEN_CTRL_01);
+
+	val = visconti_mpu_readl(pcie, PCIE_MPU_REG_MP_EN);
+	visconti_mpu_writel(pcie, val | MPU_MP_EN_DISABLE, PCIE_MPU_REG_MP_EN);
+}
+
+/*
+ * In this SoC specification, the CPU bus outputs the offset value from
+ * 0x40000000 to the PCIE bus, so 0x40000000 is subtracted from the CPU
+ * bus address. This 0x40000000 is also based on io_base from DT.
+ */
+static u64 visconti_pcie_cpu_addr_fixup(struct dw_pcie *pci, u64 cpu_addr)
+{
+	struct pcie_port *pp = &pci->pp;
+
+	return cpu_addr & ~pp->io_base;
+}
+
+static const struct dw_pcie_ops dw_pcie_ops = {
+	.cpu_addr_fixup = visconti_pcie_cpu_addr_fixup,
+	.link_up = visconti_pcie_link_up,
+	.start_link = visconti_pcie_start_link,
+	.stop_link = visconti_pcie_stop_link,
+};
+
+static int visconti_pcie_host_init(struct pcie_port *pp)
+{
+	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+	struct visconti_pcie *pcie = dev_get_drvdata(pci->dev);
+	void __iomem *addr;
+	int err;
+	u32 val;
+
+	visconti_smu_writel(pcie,
+			    PISMU_CKON_PCIE_AUX_CLK | PISMU_CKON_PCIE_MSTR_ACLK,
+			    PISMU_CKON_PCIE);
+	ndelay(250);
+
+	visconti_smu_writel(pcie, PISMU_RSOFF_PCIE_ULREG_RST_N,
+			    PISMU_RSOFF_PCIE);
+	visconti_ulreg_writel(pcie, PCIE_UL_REG_S_PCIE_MODE_RC,
+			      PCIE_UL_REG_S_PCIE_MODE);
+
+	val = PCIE_UL_REG_S_PERSTN_CTRL_INIT;
+	visconti_ulreg_writel(pcie, val, PCIE_UL_REG_S_PERSTN_CTRL);
+	udelay(100);
+
+	val |= PCIE_UL_PERSTN_OUT;
+	visconti_ulreg_writel(pcie, val, PCIE_UL_REG_S_PERSTN_CTRL);
+	udelay(100);
+
+	visconti_smu_writel(pcie, PISMU_RSOFF_PCIE_PWR_UP_RST_N,
+			    PISMU_RSOFF_PCIE);
+
+	addr = pcie->ulreg_base + PCIE_UL_REG_S_PHY_INIT_03;
+	err = readl_relaxed_poll_timeout(addr, val,
+					 (val & PCIE_UL_PHY0_SRAM_INIT_DONE),
+					 100, 1000);
+	if (err)
+		return err;
+
+	visconti_ulreg_writel(pcie, PCIE_UL_PHY0_SRAM_EXT_LD_DONE,
+			      PCIE_UL_REG_S_PHY_INIT_02);
+
+	addr = pcie->ulreg_base + PCIE_UL_REG_S_SIG_MON;
+	return readl_relaxed_poll_timeout(addr, val,
+					  (val & PCIE_UL_CORE_RST_N_MON), 100,
+					  1000);
+}
+
+static const struct dw_pcie_host_ops visconti_pcie_host_ops = {
+	.host_init = visconti_pcie_host_init,
+};
+
+static int visconti_get_resources(struct platform_device *pdev,
+				  struct visconti_pcie *pcie)
+{
+	struct device *dev = &pdev->dev;
+
+	pcie->ulreg_base = devm_platform_ioremap_resource_byname(pdev, "ulreg");
+	if (IS_ERR(pcie->ulreg_base))
+		return PTR_ERR(pcie->ulreg_base);
+
+	pcie->smu_base = devm_platform_ioremap_resource_byname(pdev, "smu");
+	if (IS_ERR(pcie->smu_base))
+		return PTR_ERR(pcie->smu_base);
+
+	pcie->mpu_base = devm_platform_ioremap_resource_byname(pdev, "mpu");
+	if (IS_ERR(pcie->mpu_base))
+		return PTR_ERR(pcie->mpu_base);
+
+	pcie->refclk = devm_clk_get(dev, "ref");
+	if (IS_ERR(pcie->refclk))
+		return dev_err_probe(dev, PTR_ERR(pcie->refclk),
+				     "Failed to get ref clock\n");
+
+	pcie->coreclk = devm_clk_get(dev, "core");
+	if (IS_ERR(pcie->coreclk))
+		return dev_err_probe(dev, PTR_ERR(pcie->coreclk),
+				     "Failed to get core clock\n");
+
+	pcie->auxclk = devm_clk_get(dev, "aux");
+	if (IS_ERR(pcie->auxclk))
+		return dev_err_probe(dev, PTR_ERR(pcie->auxclk),
+				     "Failed to get aux clock\n");
+
+	return 0;
+}
+
+static int visconti_add_pcie_port(struct visconti_pcie *pcie,
+				  struct platform_device *pdev)
+{
+	struct dw_pcie *pci = &pcie->pci;
+	struct pcie_port *pp = &pci->pp;
+	struct device *dev = &pdev->dev;
+
+	pp->irq = platform_get_irq_byname(pdev, "intr");
+	if (pp->irq < 0) {
+		dev_err(dev, "Interrupt intr is missing");
+		return pp->irq;
+	}
+
+	pp->ops = &visconti_pcie_host_ops;
+
+	return dw_pcie_host_init(pp);
+}
+
+static int visconti_pcie_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct visconti_pcie *pcie;
+	struct dw_pcie *pci;
+	int ret;
+
+	pcie = devm_kzalloc(dev, sizeof(*pcie), GFP_KERNEL);
+	if (!pcie)
+		return -ENOMEM;
+
+	pci = &pcie->pci;
+	pci->dev = dev;
+	pci->ops = &dw_pcie_ops;
+
+	ret = visconti_get_resources(pdev, pcie);
+	if (ret)
+		return ret;
+
+	platform_set_drvdata(pdev, pcie);
+
+	return visconti_add_pcie_port(pcie, pdev);
+}
+
+static const struct of_device_id visconti_pcie_match[] = {
+	{ .compatible = "toshiba,visconti-pcie" },
+	{},
+};
+
+static struct platform_driver visconti_pcie_driver = {
+	.probe = visconti_pcie_probe,
+	.driver = {
+		.name = "visconti-pcie",
+		.of_match_table = visconti_pcie_match,
+		.suppress_bind_attrs = true,
+	},
+};
+
+builtin_platform_driver(visconti_pcie_driver);
-- 
2.32.0