diff mbox series

[v5,2/3] PCI: visconti: Add Toshiba Visconti PCIe host controller driver

Message ID 20210723221421.113575-3-nobuhiro1.iwamatsu@toshiba.co.jp (mailing list archive)
State New, archived
Headers show
Series Visconti: Add Toshiba Visconti PCIe host controller driver | expand

Commit Message

Nobuhiro Iwamatsu July 23, 2021, 10:14 p.m. UTC 
Add support to PCIe RC controller on Toshiba Visconti ARM SoCs. PCIe
controller is based of Synopsys DesignWare PCIe core.

This patch does not yet use the clock framework to control the clock.
This will be replaced in the future.

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

---
 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

Comments

Lorenzo Pieralisi Aug. 5, 2021, 10:59 a.m. UTC | #1 
On Sat, Jul 24, 2021 at 07:14:20AM +0900, Nobuhiro Iwamatsu wrote:
> Add support to PCIe RC controller on Toshiba Visconti ARM SoCs. PCIe
> controller is based of Synopsys DesignWare PCIe core.
> 
> This patch does not yet use the clock framework to control the clock.
> This will be replaced in the future.

This is not relevant information. I expect the commit log to describe
the change and the reasons behind the choices.

Speaking of which, I'd like to understand what

> This patch does not yet use the clock framework to control the clock.

means and why it can't be done within this series.

> Signed-off-by: Yuji Ishikawa <yuji2.ishikawa@toshiba.co.jp>
> Signed-off-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>
> 
> ---
>  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..f01a670cdf5d
> --- /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)

Nit: don't split lines like this, it is better to keep return value
type and function name in one single line.

Do it like this:

static int visconti_add_pcie_port(struct visconti_pcie *pcie,
 				  struct platform_device *pdev)

Lorenzo

> +{
> +	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
> 
>
Nobuhiro Iwamatsu Aug. 6, 2021, 2:30 a.m. UTC | #2 
Hi,

Thank you for your review.

On Thu, Aug 05, 2021 at 11:59:08AM +0100, Lorenzo Pieralisi wrote:
> On Sat, Jul 24, 2021 at 07:14:20AM +0900, Nobuhiro Iwamatsu wrote:
> > Add support to PCIe RC controller on Toshiba Visconti ARM SoCs. PCIe
> > controller is based of Synopsys DesignWare PCIe core.
> > 
> > This patch does not yet use the clock framework to control the clock.
> > This will be replaced in the future.
> 
> This is not relevant information. I expect the commit log to describe
> the change and the reasons behind the choices.

OK, I will drop this sentence.

> 
> Speaking of which, I'd like to understand what
> 
> > This patch does not yet use the clock framework to control the clock.
> 
> means and why it can't be done within this series.

Visconti5 has a clock control IP, but the driver for this is still under
development and has not been applied into mainline. Instead, the clock
for this driver is running using DT's fixed-clock. This will be
replaced by a clock driver.

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

<snip>

> > +
> > +static int
> > +visconti_add_pcie_port(struct visconti_pcie *pcie, struct platform_device *pdev)
> 
> Nit: don't split lines like this, it is better to keep return value
> type and function name in one single line.
> 
> Do it like this:
> 
> static int visconti_add_pcie_port(struct visconti_pcie *pcie,
>  				  struct platform_device *pdev)
> 

OK, I will fix in v6.

> Lorenzo
> 


Best regards,
  Nobuhiro
diff mbox series

Patch

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..f01a670cdf5d
--- /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);