Message-Id: <20230214121333.1837-3-shradha.t@samsung.com>
Date:   Tue, 14 Feb 2023 17:43:19 +0530
From:   Shradha Todi <shradha.t@...sung.com>
To:     lpieralisi@...nel.org, kw@...ux.com, robh@...nel.org,
        bhelgaas@...gle.com, krzysztof.kozlowski+dt@...aro.org,
        alim.akhtar@...sung.com, jingoohan1@...il.com,
        Sergey.Semin@...kalelectronics.ru, lukas.bulwahn@...il.com,
        hongxing.zhu@....com, tglx@...utronix.de, m.szyprowski@...sung.com,
        jh80.chung@...sung.co, pankaj.dubey@...sung.com
Cc:     linux-pci@...r.kernel.org, devicetree@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org,
        linux-samsung-soc@...r.kernel.org, linux-kernel@...r.kernel.org,
        Shradha Todi <shradha.t@...sung.com>
Subject: [PATCH 02/16] PCI: exynos: Rename Exynos PCIe driver to Samsung
 PCIe

The current PCIe controller driver is being used for Exynos5433
SoC only. In order to extend this driver for all SoCs manufactured
by Samsung using DWC PCIe controller, rename this driver and make
it Samsung specific instead of any Samsung SoC name.

Signed-off-by: Shradha Todi <shradha.t@...sung.com>
---
 MAINTAINERS                              |   4 +-
 drivers/pci/controller/dwc/Kconfig       |   6 +-
 drivers/pci/controller/dwc/Makefile      |   2 +-
 drivers/pci/controller/dwc/pci-samsung.c | 443 +++++++++++++++++++++++
 4 files changed, 449 insertions(+), 6 deletions(-)
 create mode 100644 drivers/pci/controller/dwc/pci-samsung.c

diff --git a/MAINTAINERS b/MAINTAINERS
index a9d38274bd4d..e61374adf193 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -16084,13 +16084,13 @@ S:	Maintained
 F:	Documentation/devicetree/bindings/pci/*rcar*
 F:	drivers/pci/controller/*rcar*
 
-PCI DRIVER FOR SAMSUNG EXYNOS
+PCI DRIVER FOR SAMSUNG
 M:	Jingoo Han <jingoohan1@...il.com>
 L:	linux-pci@...r.kernel.org
 L:	linux-arm-kernel@...ts.infradead.org (moderated for non-subscribers)
 L:	linux-samsung-soc@...r.kernel.org
 S:	Maintained
-F:	drivers/pci/controller/dwc/pci-exynos.c
+F:	drivers/pci/controller/dwc/pci-samsung.c
 
 PCI DRIVER FOR SYNOPSYS DESIGNWARE
 M:	Jingoo Han <jingoohan1@...il.com>
diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig
index 434f6a4f4041..837c7693ac6e 100644
--- a/drivers/pci/controller/dwc/Kconfig
+++ b/drivers/pci/controller/dwc/Kconfig
@@ -80,13 +80,13 @@ config PCIE_DW_PLAT_EP
 	  order to enable device-specific features PCI_DW_PLAT_EP must be
 	  selected.
 
-config PCI_EXYNOS
-	tristate "Samsung Exynos PCIe controller"
+config PCI_SAMSUNG
+	tristate "Samsung PCIe controller"
 	depends on ARCH_EXYNOS || COMPILE_TEST
 	depends on PCI_MSI
 	select PCIE_DW_HOST
 	help
-	  Enables support for the PCIe controller in the Samsung Exynos SoCs
+	  Enables support for the PCIe controller in the Samsung SoCs
 	  to work in host mode. The PCI controller is based on the DesignWare
 	  hardware and therefore the driver re-uses the DesignWare core
 	  functions to implement the driver.
diff --git a/drivers/pci/controller/dwc/Makefile b/drivers/pci/controller/dwc/Makefile
index bf5c311875a1..9daf9643342d 100644
--- a/drivers/pci/controller/dwc/Makefile
+++ b/drivers/pci/controller/dwc/Makefile
@@ -5,7 +5,7 @@ obj-$(CONFIG_PCIE_DW_EP) += pcie-designware-ep.o
 obj-$(CONFIG_PCIE_DW_PLAT) += pcie-designware-plat.o
 obj-$(CONFIG_PCIE_BT1) += pcie-bt1.o
 obj-$(CONFIG_PCI_DRA7XX) += pci-dra7xx.o
-obj-$(CONFIG_PCI_EXYNOS) += pci-exynos.o
+obj-$(CONFIG_PCI_SAMSUNG) += pci-samsung.o
 obj-$(CONFIG_PCIE_FU740) += pcie-fu740.o
 obj-$(CONFIG_PCI_IMX6) += pci-imx6.o
 obj-$(CONFIG_PCIE_SPEAR13XX) += pcie-spear13xx.o
diff --git a/drivers/pci/controller/dwc/pci-samsung.c b/drivers/pci/controller/dwc/pci-samsung.c
new file mode 100644
index 000000000000..cc562a8694fb
--- /dev/null
+++ b/drivers/pci/controller/dwc/pci-samsung.c
@@ -0,0 +1,443 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PCIe host controller driver for Samsung SoCs
+ *
+ * Copyright (C) 2013 Samsung Electronics Co., Ltd.
+ *		https://www.samsung.com
+ *
+ * Author: Jingoo Han <jg1.han@...sung.com>
+ *	   Jaehoon Chung <jh80.chung@...sung.com>
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/of_device.h>
+#include <linux/pci.h>
+#include <linux/platform_device.h>
+#include <linux/phy/phy.h>
+#include <linux/regulator/consumer.h>
+#include <linux/module.h>
+
+#include "pcie-designware.h"
+
+#define to_exynos_pcie(x)	dev_get_drvdata((x)->dev)
+
+/* PCIe ELBI registers */
+#define PCIE_IRQ_PULSE			0x000
+#define IRQ_INTA_ASSERT			BIT(0)
+#define IRQ_INTB_ASSERT			BIT(2)
+#define IRQ_INTC_ASSERT			BIT(4)
+#define IRQ_INTD_ASSERT			BIT(6)
+#define PCIE_IRQ_LEVEL			0x004
+#define PCIE_IRQ_SPECIAL		0x008
+#define PCIE_IRQ_EN_PULSE		0x00c
+#define PCIE_IRQ_EN_LEVEL		0x010
+#define PCIE_IRQ_EN_SPECIAL		0x014
+#define PCIE_SW_WAKE			0x018
+#define PCIE_BUS_EN			BIT(1)
+#define PCIE_CORE_RESET			0x01c
+#define PCIE_CORE_RESET_ENABLE		BIT(0)
+#define PCIE_STICKY_RESET		0x020
+#define PCIE_NONSTICKY_RESET		0x024
+#define PCIE_APP_INIT_RESET		0x028
+#define PCIE_APP_LTSSM_ENABLE		0x02c
+#define PCIE_ELBI_RDLH_LINKUP		0x074
+#define PCIE_ELBI_XMLH_LINKUP		BIT(4)
+#define PCIE_ELBI_LTSSM_ENABLE		0x1
+#define PCIE_ELBI_SLV_AWMISC		0x11c
+#define PCIE_ELBI_SLV_ARMISC		0x120
+#define PCIE_ELBI_SLV_DBI_ENABLE	BIT(21)
+
+struct exynos_pcie {
+	struct dw_pcie			pci;
+	void __iomem			*elbi_base;
+	struct clk			*clk;
+	struct clk			*bus_clk;
+	struct phy			*phy;
+	struct regulator_bulk_data	supplies[2];
+};
+
+static int exynos_pcie_init_clk_resources(struct exynos_pcie *ep)
+{
+	struct device *dev = ep->pci.dev;
+	int ret;
+
+	ret = clk_prepare_enable(ep->clk);
+	if (ret) {
+		dev_err(dev, "cannot enable pcie rc clock");
+		return ret;
+	}
+
+	ret = clk_prepare_enable(ep->bus_clk);
+	if (ret) {
+		dev_err(dev, "cannot enable pcie bus clock");
+		goto err_bus_clk;
+	}
+
+	return 0;
+
+err_bus_clk:
+	clk_disable_unprepare(ep->clk);
+
+	return ret;
+}
+
+static void exynos_pcie_deinit_clk_resources(struct exynos_pcie *ep)
+{
+	clk_disable_unprepare(ep->bus_clk);
+	clk_disable_unprepare(ep->clk);
+}
+
+static void exynos_pcie_writel(void __iomem *base, u32 val, u32 reg)
+{
+	writel(val, base + reg);
+}
+
+static u32 exynos_pcie_readl(void __iomem *base, u32 reg)
+{
+	return readl(base + reg);
+}
+
+static void exynos_pcie_sideband_dbi_w_mode(struct exynos_pcie *ep, bool on)
+{
+	u32 val;
+
+	val = exynos_pcie_readl(ep->elbi_base, PCIE_ELBI_SLV_AWMISC);
+	if (on)
+		val |= PCIE_ELBI_SLV_DBI_ENABLE;
+	else
+		val &= ~PCIE_ELBI_SLV_DBI_ENABLE;
+	exynos_pcie_writel(ep->elbi_base, val, PCIE_ELBI_SLV_AWMISC);
+}
+
+static void exynos_pcie_sideband_dbi_r_mode(struct exynos_pcie *ep, bool on)
+{
+	u32 val;
+
+	val = exynos_pcie_readl(ep->elbi_base, PCIE_ELBI_SLV_ARMISC);
+	if (on)
+		val |= PCIE_ELBI_SLV_DBI_ENABLE;
+	else
+		val &= ~PCIE_ELBI_SLV_DBI_ENABLE;
+	exynos_pcie_writel(ep->elbi_base, val, PCIE_ELBI_SLV_ARMISC);
+}
+
+static void exynos_pcie_assert_core_reset(struct exynos_pcie *ep)
+{
+	u32 val;
+
+	val = exynos_pcie_readl(ep->elbi_base, PCIE_CORE_RESET);
+	val &= ~PCIE_CORE_RESET_ENABLE;
+	exynos_pcie_writel(ep->elbi_base, val, PCIE_CORE_RESET);
+	exynos_pcie_writel(ep->elbi_base, 0, PCIE_STICKY_RESET);
+	exynos_pcie_writel(ep->elbi_base, 0, PCIE_NONSTICKY_RESET);
+}
+
+static void exynos_pcie_deassert_core_reset(struct exynos_pcie *ep)
+{
+	u32 val;
+
+	val = exynos_pcie_readl(ep->elbi_base, PCIE_CORE_RESET);
+	val |= PCIE_CORE_RESET_ENABLE;
+
+	exynos_pcie_writel(ep->elbi_base, val, PCIE_CORE_RESET);
+	exynos_pcie_writel(ep->elbi_base, 1, PCIE_STICKY_RESET);
+	exynos_pcie_writel(ep->elbi_base, 1, PCIE_NONSTICKY_RESET);
+	exynos_pcie_writel(ep->elbi_base, 1, PCIE_APP_INIT_RESET);
+	exynos_pcie_writel(ep->elbi_base, 0, PCIE_APP_INIT_RESET);
+}
+
+static int exynos_pcie_start_link(struct dw_pcie *pci)
+{
+	struct exynos_pcie *ep = to_exynos_pcie(pci);
+	u32 val;
+
+	val = exynos_pcie_readl(ep->elbi_base, PCIE_SW_WAKE);
+	val &= ~PCIE_BUS_EN;
+	exynos_pcie_writel(ep->elbi_base, val, PCIE_SW_WAKE);
+
+	/* assert LTSSM enable */
+	exynos_pcie_writel(ep->elbi_base, PCIE_ELBI_LTSSM_ENABLE,
+			  PCIE_APP_LTSSM_ENABLE);
+	return 0;
+}
+
+static void exynos_pcie_clear_irq_pulse(struct exynos_pcie *ep)
+{
+	u32 val = exynos_pcie_readl(ep->elbi_base, PCIE_IRQ_PULSE);
+
+	exynos_pcie_writel(ep->elbi_base, val, PCIE_IRQ_PULSE);
+}
+
+static irqreturn_t exynos_pcie_irq_handler(int irq, void *arg)
+{
+	struct exynos_pcie *ep = arg;
+
+	exynos_pcie_clear_irq_pulse(ep);
+	return IRQ_HANDLED;
+}
+
+static void exynos_pcie_enable_irq_pulse(struct exynos_pcie *ep)
+{
+	u32 val = IRQ_INTA_ASSERT | IRQ_INTB_ASSERT |
+		  IRQ_INTC_ASSERT | IRQ_INTD_ASSERT;
+
+	exynos_pcie_writel(ep->elbi_base, val, PCIE_IRQ_EN_PULSE);
+	exynos_pcie_writel(ep->elbi_base, 0, PCIE_IRQ_EN_LEVEL);
+	exynos_pcie_writel(ep->elbi_base, 0, PCIE_IRQ_EN_SPECIAL);
+}
+
+static u32 exynos_pcie_read_dbi(struct dw_pcie *pci, void __iomem *base,
+				u32 reg, size_t size)
+{
+	struct exynos_pcie *ep = to_exynos_pcie(pci);
+	u32 val;
+
+	exynos_pcie_sideband_dbi_r_mode(ep, true);
+	dw_pcie_read(base + reg, size, &val);
+	exynos_pcie_sideband_dbi_r_mode(ep, false);
+	return val;
+}
+
+static void exynos_pcie_write_dbi(struct dw_pcie *pci, void __iomem *base,
+				  u32 reg, size_t size, u32 val)
+{
+	struct exynos_pcie *ep = to_exynos_pcie(pci);
+
+	exynos_pcie_sideband_dbi_w_mode(ep, true);
+	dw_pcie_write(base + reg, size, val);
+	exynos_pcie_sideband_dbi_w_mode(ep, false);
+}
+
+static int exynos_pcie_rd_own_conf(struct pci_bus *bus, unsigned int devfn,
+				   int where, int size, u32 *val)
+{
+	struct dw_pcie *pci = to_dw_pcie_from_pp(bus->sysdata);
+
+	if (PCI_SLOT(devfn))
+		return PCIBIOS_DEVICE_NOT_FOUND;
+
+	*val = dw_pcie_read_dbi(pci, where, size);
+	return PCIBIOS_SUCCESSFUL;
+}
+
+static int exynos_pcie_wr_own_conf(struct pci_bus *bus, unsigned int devfn,
+				   int where, int size, u32 val)
+{
+	struct dw_pcie *pci = to_dw_pcie_from_pp(bus->sysdata);
+
+	if (PCI_SLOT(devfn))
+		return PCIBIOS_DEVICE_NOT_FOUND;
+
+	dw_pcie_write_dbi(pci, where, size, val);
+	return PCIBIOS_SUCCESSFUL;
+}
+
+static struct pci_ops exynos_pci_ops = {
+	.read = exynos_pcie_rd_own_conf,
+	.write = exynos_pcie_wr_own_conf,
+};
+
+static int exynos_pcie_link_up(struct dw_pcie *pci)
+{
+	struct exynos_pcie *ep = to_exynos_pcie(pci);
+	u32 val = exynos_pcie_readl(ep->elbi_base, PCIE_ELBI_RDLH_LINKUP);
+
+	return (val & PCIE_ELBI_XMLH_LINKUP);
+}
+
+static int exynos_pcie_host_init(struct dw_pcie_rp *pp)
+{
+	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+	struct exynos_pcie *ep = to_exynos_pcie(pci);
+
+	pp->bridge->ops = &exynos_pci_ops;
+
+	exynos_pcie_assert_core_reset(ep);
+
+	phy_init(ep->phy);
+	phy_power_on(ep->phy);
+
+	exynos_pcie_deassert_core_reset(ep);
+	exynos_pcie_enable_irq_pulse(ep);
+
+	return 0;
+}
+
+static const struct dw_pcie_host_ops exynos_pcie_host_ops = {
+	.host_init = exynos_pcie_host_init,
+};
+
+static int exynos_add_pcie_port(struct exynos_pcie *ep,
+				       struct platform_device *pdev)
+{
+	struct dw_pcie *pci = &ep->pci;
+	struct dw_pcie_rp *pp = &pci->pp;
+	struct device *dev = &pdev->dev;
+	int ret;
+
+	pp->irq = platform_get_irq(pdev, 0);
+	if (pp->irq < 0)
+		return pp->irq;
+
+	ret = devm_request_irq(dev, pp->irq, exynos_pcie_irq_handler,
+			       IRQF_SHARED, "exynos-pcie", ep);
+	if (ret) {
+		dev_err(dev, "failed to request irq\n");
+		return ret;
+	}
+
+	pp->ops = &exynos_pcie_host_ops;
+	pp->msi_irq[0] = -ENODEV;
+
+	ret = dw_pcie_host_init(pp);
+	if (ret) {
+		dev_err(dev, "failed to initialize host\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static const struct dw_pcie_ops dw_pcie_ops = {
+	.read_dbi = exynos_pcie_read_dbi,
+	.write_dbi = exynos_pcie_write_dbi,
+	.link_up = exynos_pcie_link_up,
+	.start_link = exynos_pcie_start_link,
+};
+
+static int exynos_pcie_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct exynos_pcie *ep;
+	struct device_node *np = dev->of_node;
+	int ret;
+
+	ep = devm_kzalloc(dev, sizeof(*ep), GFP_KERNEL);
+	if (!ep)
+		return -ENOMEM;
+
+	ep->pci.dev = dev;
+	ep->pci.ops = &dw_pcie_ops;
+
+	ep->phy = devm_of_phy_get(dev, np, NULL);
+	if (IS_ERR(ep->phy))
+		return PTR_ERR(ep->phy);
+
+	/* External Local Bus interface (ELBI) registers */
+	ep->elbi_base = devm_platform_ioremap_resource_byname(pdev, "elbi");
+	if (IS_ERR(ep->elbi_base))
+		return PTR_ERR(ep->elbi_base);
+
+	ep->clk = devm_clk_get(dev, "pcie");
+	if (IS_ERR(ep->clk)) {
+		dev_err(dev, "Failed to get pcie rc clock\n");
+		return PTR_ERR(ep->clk);
+	}
+
+	ep->bus_clk = devm_clk_get(dev, "pcie_bus");
+	if (IS_ERR(ep->bus_clk)) {
+		dev_err(dev, "Failed to get pcie bus clock\n");
+		return PTR_ERR(ep->bus_clk);
+	}
+
+	ep->supplies[0].supply = "vdd18";
+	ep->supplies[1].supply = "vdd10";
+	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(ep->supplies),
+				      ep->supplies);
+	if (ret)
+		return ret;
+
+	ret = exynos_pcie_init_clk_resources(ep);
+	if (ret)
+		return ret;
+
+	ret = regulator_bulk_enable(ARRAY_SIZE(ep->supplies), ep->supplies);
+	if (ret)
+		return ret;
+
+	platform_set_drvdata(pdev, ep);
+
+	ret = exynos_add_pcie_port(ep, pdev);
+	if (ret < 0)
+		goto fail_probe;
+
+	return 0;
+
+fail_probe:
+	phy_exit(ep->phy);
+	exynos_pcie_deinit_clk_resources(ep);
+	regulator_bulk_disable(ARRAY_SIZE(ep->supplies), ep->supplies);
+
+	return ret;
+}
+
+static int __exit exynos_pcie_remove(struct platform_device *pdev)
+{
+	struct exynos_pcie *ep = platform_get_drvdata(pdev);
+
+	dw_pcie_host_deinit(&ep->pci.pp);
+	exynos_pcie_assert_core_reset(ep);
+	phy_power_off(ep->phy);
+	phy_exit(ep->phy);
+	exynos_pcie_deinit_clk_resources(ep);
+	regulator_bulk_disable(ARRAY_SIZE(ep->supplies), ep->supplies);
+
+	return 0;
+}
+
+static int exynos_pcie_suspend_noirq(struct device *dev)
+{
+	struct exynos_pcie *ep = dev_get_drvdata(dev);
+
+	exynos_pcie_assert_core_reset(ep);
+	phy_power_off(ep->phy);
+	phy_exit(ep->phy);
+	regulator_bulk_disable(ARRAY_SIZE(ep->supplies), ep->supplies);
+
+	return 0;
+}
+
+static int exynos_pcie_resume_noirq(struct device *dev)
+{
+	struct exynos_pcie *ep = dev_get_drvdata(dev);
+	struct dw_pcie *pci = &ep->pci;
+	struct dw_pcie_rp *pp = &pci->pp;
+	int ret;
+
+	ret = regulator_bulk_enable(ARRAY_SIZE(ep->supplies), ep->supplies);
+	if (ret)
+		return ret;
+
+	/* exynos_pcie_host_init controls ep->phy */
+	exynos_pcie_host_init(pp);
+	dw_pcie_setup_rc(pp);
+	exynos_pcie_start_link(pci);
+	return dw_pcie_wait_for_link(pci);
+}
+
+static const struct dev_pm_ops exynos_pcie_pm_ops = {
+	NOIRQ_SYSTEM_SLEEP_PM_OPS(exynos_pcie_suspend_noirq,
+				  exynos_pcie_resume_noirq)
+};
+
+static const struct of_device_id exynos_pcie_of_match[] = {
+	{ .compatible = "samsung,exynos5433-pcie", },
+	{ },
+};
+
+static struct platform_driver exynos_pcie_driver = {
+	.probe		= exynos_pcie_probe,
+	.remove		= __exit_p(exynos_pcie_remove),
+	.driver = {
+		.name	= "exynos-pcie",
+		.of_match_table = exynos_pcie_of_match,
+		.pm		= &exynos_pcie_pm_ops,
+	},
+};
+module_platform_driver(exynos_pcie_driver);
+MODULE_LICENSE("GPL v2");
+MODULE_DEVICE_TABLE(of, exynos_pcie_of_match);
-- 
2.17.1

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