Message-id: <36428745-1880-b8fb-c718-530b6d3d3512@samsung.com>
Date:   Tue, 27 Dec 2016 10:43:08 +0900
From:   Jaehoon Chung <jh80.chung@...sung.com>
To:     Joao Pinto <Joao.Pinto@...opsys.com>, linux-pci@...r.kernel.org
Cc:     devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-samsung-soc@...r.kernel.org, bhelgaas@...gle.com,
        robh+dt@...nel.org, mark.rutland@....com, kgene@...nel.org,
        krzk@...nel.org, javier@....samsung.com, kishon@...com,
        will.deacon@....com, catalin.marinas@....com, cpgs@...sung.com
Subject: Re: [RFC PATCH 4/6] PCI: exynos5433: Add new exynos pci host
 controller for Exynos5433

On 12/26/2016 08:49 PM, Joao Pinto wrote:
> 
> Hello Jaehoon,
> 
> Às 5:20 AM de 12/26/2016, Jaehoon Chung escreveu:
>> Exynos5433 supports the PCIe.
>> This patch adds new pci-exynos5433.c file for Exynos ARM64.
>>
>> Signed-off-by: Jaehoon Chung <jh80.chung@...sung.com>
>> ---
>>  drivers/pci/host/Kconfig          |   9 +
>>  drivers/pci/host/Makefile         |   1 +
>>  drivers/pci/host/pci-exynos5433.c | 338 ++++++++++++++++++++++++++++++++++++++
>>  3 files changed, 348 insertions(+)
>>  create mode 100644 drivers/pci/host/pci-exynos5433.c
>>
>> diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig
>> index d7e7c0a..3d77d0b 100644
>> --- a/drivers/pci/host/Kconfig
>> +++ b/drivers/pci/host/Kconfig
>> @@ -60,6 +60,15 @@ config PCI_EXYNOS
>>  	select PCIEPORTBUS
>>  	select PCIE_DW
>>  
>> +config PCI_EXYNOS5433
>> +	bool "Samsung Exynos5433 PCIe controller"
>> +	depends on ARCH_EXYNOS && ARM64
>> +	depends on PCI_MSI_IRQ_DOMAIN
>> +	select PCIEPORTBUS
>> +	select PCIE_DW
>> +	help
>> +	  If you want support for Exynos5433 PCIe host controller, say Y.
>> +
>>  config PCI_IMX6
>>  	bool "Freescale i.MX6 PCIe controller"
>>  	depends on SOC_IMX6Q
>> diff --git a/drivers/pci/host/Makefile b/drivers/pci/host/Makefile
>> index 084cb49..2168de2 100644
>> --- a/drivers/pci/host/Makefile
>> +++ b/drivers/pci/host/Makefile
>> @@ -2,6 +2,7 @@ obj-$(CONFIG_PCIE_DW) += pcie-designware.o
>>  obj-$(CONFIG_PCIE_DW_PLAT) += pcie-designware-plat.o
>>  obj-$(CONFIG_PCI_DRA7XX) += pci-dra7xx.o
>>  obj-$(CONFIG_PCI_EXYNOS) += pci-exynos.o
>> +obj-$(CONFIG_PCI_EXYNOS5433) += pci-exynos5433.o
>>  obj-$(CONFIG_PCI_IMX6) += pci-imx6.o
>>  obj-$(CONFIG_PCI_HYPERV) += pci-hyperv.o
>>  obj-$(CONFIG_PCI_MVEBU) += pci-mvebu.o
>> diff --git a/drivers/pci/host/pci-exynos5433.c b/drivers/pci/host/pci-exynos5433.c
>> new file mode 100644
>> index 0000000..ff254ca
>> --- /dev/null
>> +++ b/drivers/pci/host/pci-exynos5433.c
>> @@ -0,0 +1,338 @@
>> +/*
>> + * PCIe host controller driver for Samsung EXYNOS5433 SoCs
>> + *
>> + * Copyright (C) 2016 Samsung Electronics Co., Ltd.
>> + *		https://urldefense.proofpoint.com/v2/url?u=http-3A__www.samsung.com&d=DgIBAg&c=DPL6_X_6JkXFx7AXWqB0tg&r=s2fO0hii0OGNOv9qQy_HRXy-xAJUD1NNoEcc3io_kx0&m=fUwnZks1U2AwaOxMkLdSnE700sfQXpB3WAg_EJw7NaE&s=IwRYD8maTuXG57Q0qlAmFNh3_TSfUTE27xq8p13FFKI&e= 
>> + *
>> + * 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/gpio.h>
>> +#include <linux/delay.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/kernel.h>
>> +#include <linux/module.h>
>> +#include <linux/of_gpio.h>
>> +#include <linux/pci.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/regmap.h>
>> +#include <linux/resource.h>
>> +#include <linux/signal.h>
>> +#include <linux/types.h>
>> +#include <linux/mfd/syscon.h>
>> +#include <linux/phy/phy.h>
>> +
>> +#include "pcie-designware.h"
>> +
>> +#define to_exynos_pcie(x)	container_of(x, struct exynos_pcie, pp)
>> +
>> +/* Pcie structure for Exynos specific data */
>> +struct exynos_pcie {
>> +	void __iomem		*elbi_base;
>> +	struct clk		*clk;
>> +	struct clk		*bus_clk;
>> +	struct pcie_port	pp;
>> +	struct phy		*phy;
>> +};
>> +
>> +/* 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 IRQ_INTX_ASSERT	(IRQ_INTA_ASSERT | IRQ_INTB_ASSERT | \
>> +			IRQ_INTC_ASSERT | IRQ_INTD_ASSERT)
>> +#define PCIE_IRQ_EN_PULSE		0x00c
>> +#define PCIE_IRQ_EN_LEVEL		0x010
>> +#define PCIE_SW_WAKE			0x018
>> +#define PCIE_BUS_EN			BIT(1)
>> +#define PCIE_APP_LTSSM_ENABLE		0x02c
>> +#define PCIE_ELBI_LTSSM_ENABLE		0x1
>> +#define PCIE_ELBI_DEBUG_L		0x074
>> +#define PCIE_ELBI_XMLH_LINK_UP		BIT(4)
>> +#define PCIE_ELBI_SLV_AWMISC		0x11c
>> +#define PCIE_ELBI_SLV_ARMISC		0x120
>> +#define PCIE_ELBI_SLV_DBI_ENABLE	BIT(21)
>> +
>> +/* DBI register */
>> +#define PCIE_MISC_CONTROL_1_OFF		0x8BC
>> +#define DBI_RO_WR_EN			BIT(0)
>> +
>> +static inline void exynos_pcie_writel(void __iomem *base, u32 val, u32 offset)
>> +{
>> +	writel(val, base + offset);
>> +}
>> +
>> +static inline u32 exynos_pcie_readl(void __iomem *base, u32 offset)
>> +{
>> +	return readl(base + offset);
>> +}
>> +
>> +static void exynos_pcie_clear_irq_pulse(struct exynos_pcie *ep)
>> +{
>> +	u32 val;
>> +
>> +	val = exynos_pcie_readl(ep->elbi_base, PCIE_IRQ_PULSE);
>> +	val &= ~IRQ_INTX_ASSERT;
>> +	exynos_pcie_writel(ep->elbi_base, val, PCIE_IRQ_PULSE);
>> +}
>> +
>> +static void exynos_pcie_enable_irq_pulse(struct exynos_pcie *ep)
>> +{
>> +	exynos_pcie_writel(ep->elbi_base, IRQ_INTX_ASSERT, PCIE_IRQ_EN_PULSE);
>> +
>> +	/* Clear PCIE_IRQ_EN_LEVEL register */
>> +	exynos_pcie_writel(ep->elbi_base, 0, PCIE_IRQ_EN_LEVEL);
>> +}
>> +
>> +static irqreturn_t exynos_pcie_irq_handler(int irq, void *arg)
>> +{
>> +	struct pcie_port *pp = arg;
>> +	struct exynos_pcie *ep = to_exynos_pcie(pp);
>> +
>> +	exynos_pcie_clear_irq_pulse(ep);
>> +
>> +	return IRQ_HANDLED;
>> +}
>> +
>> +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 int exynos_pcie_establish_link(struct exynos_pcie *ep)
>> +{
>> +	struct pcie_port *pp = &ep->pp;
>> +	u32 val;
>> +
>> +	if (dw_pcie_link_up(pp)) {
>> +		dev_info(pp->dev, "Link already up\n");
>> +		return 0;
>> +	}
>> +
>> +	phy_power_on(ep->phy);
>> +
>> +	/* Exynos Pcie assert PHY reset  and init */
>> +	phy_init(ep->phy);
>> +
>> +	val = exynos_pcie_readl(ep->elbi_base, PCIE_SW_WAKE);
>> +	val &= ~PCIE_BUS_EN;
>> +	exynos_pcie_writel(ep->elbi_base, val, PCIE_SW_WAKE);
>> +
>> +	/*
>> +	 * Enable DBI_RO_WR_EN bit.
>> +	 * - When set to 1, some RO and HWinit bits are wriatble from
>> +	 *   the local application through the DBI.
>> +	 */
>> +	dw_pcie_writel_rc(pp, PCIE_MISC_CONTROL_1_OFF, DBI_RO_WR_EN);
>> +
>> +	/* Setup root complex */
>> +	dw_pcie_setup_rc(pp);
>> +
>> +	/* assert LTSSM enable */
>> +	exynos_pcie_writel(ep->elbi_base, PCIE_ELBI_LTSSM_ENABLE,
>> +			PCIE_APP_LTSSM_ENABLE);
>> +
>> +	return dw_pcie_wait_for_link(pp);
>> +}
>> +
>> +
>> +static int exynos_pcie_link_up(struct pcie_port *pp)
>> +{
>> +	struct exynos_pcie *ep = to_exynos_pcie(pp);
>> +	u32 val;
>> +
>> +	/* Check the Receive Transaction Layer Handler */
>> +	val = exynos_pcie_readl(ep->elbi_base, PCIE_ELBI_DEBUG_L);
>> +
>> +	return (val & PCIE_ELBI_XMLH_LINK_UP);
>> +}
>> +
>> +static void exynos_pcie_host_init(struct pcie_port *pp)
>> +{
>> +	struct exynos_pcie *ep = to_exynos_pcie(pp);
>> +
>> +	exynos_pcie_enable_irq_pulse(ep);
>> +	exynos_pcie_establish_link(ep);
>> +}
> 
> Your *_host_init callback should return to pci-designware its error/success
> status. There is a recent patch that added this capability to all vendor
> specific drivers that use pcie-designware. Please check it out and follow the
> same approach:
> https://patchwork.kernel.org/patch/9464223/

Ok, I will check it. Thanks for noticing it.

Best Regards,
Jaehoon Chung

> 
> Thanks,
> Joao
> 
>> +
>> +static u32 exynos_pcie_readl_rc(struct pcie_port *pp, u32 reg)
>> +{
>> +	struct exynos_pcie *exynos_pcie = to_exynos_pcie(pp);
>> +	u32 val;
>> +
>> +	exynos_pcie_sideband_dbi_r_mode(exynos_pcie, true);
>> +	val = readl(pp->dbi_base + reg);
>> +	exynos_pcie_sideband_dbi_r_mode(exynos_pcie, false);
>> +	return val;
>> +}
>> +
>> +static void exynos_pcie_writel_rc(struct pcie_port *pp, u32 reg, u32 val)
>> +{
>> +	struct exynos_pcie *exynos_pcie = to_exynos_pcie(pp);
>> +
>> +	exynos_pcie_sideband_dbi_w_mode(exynos_pcie, true);
>> +	writel(val, pp->dbi_base + reg);
>> +	exynos_pcie_sideband_dbi_w_mode(exynos_pcie, false);
>> +}
>> +
>> +static int exynos_pcie_rd_own_conf(struct pcie_port *pp, int where, int size,
>> +				u32 *val)
>> +{
>> +	struct exynos_pcie *exynos_pcie = to_exynos_pcie(pp);
>> +	int ret;
>> +
>> +	exynos_pcie_sideband_dbi_r_mode(exynos_pcie, true);
>> +	ret = dw_pcie_cfg_read(pp->dbi_base + where, size, val);
>> +	exynos_pcie_sideband_dbi_r_mode(exynos_pcie, false);
>> +	return ret;
>> +}
>> +
>> +static int exynos_pcie_wr_own_conf(struct pcie_port *pp, int where, int size,
>> +				u32 val)
>> +{
>> +	struct exynos_pcie *exynos_pcie = to_exynos_pcie(pp);
>> +	int ret;
>> +
>> +	exynos_pcie_sideband_dbi_w_mode(exynos_pcie, true);
>> +	ret = dw_pcie_cfg_write(pp->dbi_base + where, size, val);
>> +	exynos_pcie_sideband_dbi_w_mode(exynos_pcie, false);
>> +	return ret;
>> +}
>> +
>> +static struct pcie_host_ops exynos_pcie_host_ops = {
>> +	.readl_rc = exynos_pcie_readl_rc,
>> +	.writel_rc = exynos_pcie_writel_rc,
>> +	.rd_own_conf = exynos_pcie_rd_own_conf,
>> +	.wr_own_conf = exynos_pcie_wr_own_conf,
>> +	.host_init = exynos_pcie_host_init,
>> +	.link_up = exynos_pcie_link_up,
>> +};
>> +
>> +static int __init exynos_pcie_probe(struct platform_device *pdev)
>> +{
>> +	struct exynos_pcie *exynos_pcie;
>> +	struct pcie_port *pp;
>> +	struct resource *res;
>> +	int ret;
>> +
>> +	exynos_pcie = devm_kzalloc(&pdev->dev, sizeof(*exynos_pcie),
>> +			GFP_KERNEL);
>> +	if (!exynos_pcie)
>> +		return -ENOMEM;
>> +
>> +	pp = &exynos_pcie->pp;
>> +	pp->dev = &pdev->dev;
>> +
>> +	exynos_pcie->clk = devm_clk_get(&pdev->dev, "pcie");
>> +	if (IS_ERR(exynos_pcie->clk)) {
>> +		dev_err(&pdev->dev, "Failed to get pcie rc clock\n");
>> +		return PTR_ERR(exynos_pcie->clk);
>> +	}
>> +	ret = clk_prepare_enable(exynos_pcie->clk);
>> +	if (ret)
>> +		return ret;
>> +
>> +	exynos_pcie->bus_clk = devm_clk_get(&pdev->dev, "pcie_bus");
>> +	if (IS_ERR(exynos_pcie->bus_clk)) {
>> +		dev_err(&pdev->dev, "Failed to get pcie bus clock\n");
>> +		ret = PTR_ERR(exynos_pcie->bus_clk);
>> +		goto fail_clk;
>> +	}
>> +	ret = clk_prepare_enable(exynos_pcie->bus_clk);
>> +	if (ret)
>> +		goto fail_clk;
>> +
>> +	/* External Local Bus interface(ELBI) Register */
>> +	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "elbi");
>> +	exynos_pcie->elbi_base = devm_ioremap_resource(&pdev->dev, res);
>> +	if (IS_ERR(exynos_pcie->elbi_base)) {
>> +		ret = PTR_ERR(exynos_pcie->elbi_base);
>> +		goto fail_bus_clk;
>> +	}
>> +
>> +	/* Data Bus Interface(DBI) Register */
>> +	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dbi");
>> +	pp->dbi_base = devm_ioremap_resource(&pdev->dev, res);
>> +	if (IS_ERR(pp->dbi_base)) {
>> +		ret = PTR_ERR(pp->dbi_base);
>> +		goto fail_bus_clk;
>> +	}
>> +
>> +	exynos_pcie->phy = devm_phy_get(&pdev->dev, "pcie-phy");
>> +	if (IS_ERR(exynos_pcie->phy)) {
>> +		if (PTR_ERR(exynos_pcie->phy) != -EPROBE_DEFER)
>> +			dev_err(&pdev->dev, "Can't find the pcie-phy\n");
>> +		return PTR_ERR(exynos_pcie->phy);
>> +	}
>> +
>> +	pp->irq = platform_get_irq_byname(pdev, "intr");
>> +	if (!pp->irq) {
>> +		dev_err(&pdev->dev, "failed to get irq\n");
>> +		ret = -ENODEV;
>> +		goto fail_bus_clk;
>> +	}
>> +	ret = devm_request_irq(&pdev->dev, pp->irq, exynos_pcie_irq_handler,
>> +				IRQF_SHARED, "exynos-pcie", exynos_pcie);
>> +	if (ret) {
>> +		dev_err(&pdev->dev, "failed to request irq\n");
>> +		goto fail_bus_clk;
>> +	}
>> +
>> +	pp->root_bus_nr = -1;
>> +	pp->ops = &exynos_pcie_host_ops;
>> +
>> +	ret = dw_pcie_host_init(pp);
>> +	if (ret) {
>> +		dev_err(&pdev->dev, "failed to initialize host\n");
>> +		goto fail_bus_clk;
>> +	}
>> +
>> +	platform_set_drvdata(pdev, exynos_pcie);
>> +
>> +	return 0;
>> +
>> +fail_bus_clk:
>> +	clk_disable_unprepare(exynos_pcie->bus_clk);
>> +fail_clk:
>> +	clk_disable_unprepare(exynos_pcie->clk);
>> +	return ret;
>> +}
>> +
>> +static const struct of_device_id exynos_pcie_of_match[] = {
>> +	{ .compatible = "samsung,exynos5433-pcie", },
>> +	{},
>> +};
>> +MODULE_DEVICE_TABLE(of, exynos_pcie_of_match);
>> +
>> +static struct platform_driver exynos_pcie_driver = {
>> +	.probe		= exynos_pcie_probe,
>> +	.driver		= {
>> +		.name		= "exynos5433-pcie",
>> +		.of_match_table = exynos_pcie_of_match,
>> +	},
>> +};
>> +builtin_platform_driver(exynos_pcie_driver);
>>
> 
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