Re: [PATCH v6] PCI: Layerscape: Add Layerscape PCIe driver

[Bjorn Helgaas <bhelgaas@google.com>]

On Wed, Nov 05, 2014 at 04:45:11PM +0800, Minghuan Lian wrote:
> Add support for Freescale Layerscape PCIe controller. This driver
> re-uses the designware core code.
> 
> Signed-off-by: Minghuan Lian <Minghuan.Lian@freescale.com>

Applied with Arnd's ack to pci/host-layerscape for v3.19, thanks!

> ---
> Based on pci-next branch
> 
> Change log:
> v6:
> 1. remove MSI support. MSI driver will be implemented in a separate file
> 2. remove bitrev() because SCFG is set bit reverse mode as default.
> 
> v5:
> 1. Add MAINTAINERS information
> 2. Remove unnecessary NULL pointer check
> 3. Use dev_dbg instead of dev_err in ls_pcie_msi_irq_handler() 
> 
> v4:
> 1. Add 'depends on OF' to Kconfig 
> 
> v3:
> 1. Add prefechable mem region and adjust mem region
> 2. Rename 'pcie-scfg' to 'fsl,pcie-scfg'
> 3. Change MSI interrupt handler
> 4. Use module_platform_driver_probe instead of subsys_initcall
> 
> v2:
> 1. Add pcie-scfg to link scfg device node and remove "fsl, ls-pcie" compatible
> 2. Use regmap API to access scfg.
> 3. remove ls1021 PCI device ID.
> 4. remove unused irq pme_irq and ls_pcie_list.
> 5. Do not set scfg bit reverse mode
> 
>  .../devicetree/bindings/pci/layerscape-pci.txt     |  42 +++++
>  MAINTAINERS                                        |  10 ++
>  drivers/pci/host/Kconfig                           |   8 +
>  drivers/pci/host/Makefile                          |   1 +
>  drivers/pci/host/pci-layerscape.c                  | 179 +++++++++++++++++++++
>  5 files changed, 240 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/pci/layerscape-pci.txt
>  create mode 100644 drivers/pci/host/pci-layerscape.c
> 
> diff --git a/Documentation/devicetree/bindings/pci/layerscape-pci.txt b/Documentation/devicetree/bindings/pci/layerscape-pci.txt
> new file mode 100644
> index 0000000..40749eb
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/pci/layerscape-pci.txt
> @@ -0,0 +1,42 @@
> +Freescale Layerscape PCIe controller
> +
> +This PCIe host controller is based on the Synopsis Designware PCIe IP
> +and thus inherits all the common properties defined in designware-pcie.txt.
> +
> +Required properties:
> +- compatible: should contain the platform identifier such as "fsl,ls1021a-pcie"
> +- reg: base addresses and lengths of the PCIe controller
> +- interrupts: A list of interrupt outputs of the controller. Must contain an
> +  entry for each entry in the interrupt-names property.
> +- interrupt-names: Must include the following entries:
> +  "intr": The interrupt that is asserted for controller interrupts
> +- fsl,pcie-scfg: Must include two entries.
> +  The first entry must be a link to the SCFG device node
> +  The second entry must be '0' or '1' based on physical PCIe controller index.
> +  used to get SCFG PEXN registers
> +
> +Example:
> +
> +	pcie@3400000 {
> +		compatible = "fsl,ls1021a-pcie", "snps,dw-pcie";
> +		reg = <0x00 0x03400000 0x0 0x00010000   /* controller registers */
> +		       0x40 0x00000000 0x0 0x00002000>; /* configuration space */
> +		reg-names = "regs", "config";
> +		interrupts = <GIC_SPI 177 IRQ_TYPE_LEVEL_HIGH>; /* controller interrupt */
> +		interrupt-names = "intr";
> +		fsl,pcie-scfg = <&scfg 0>;
> +		#address-cells = <3>;
> +		#size-cells = <2>;
> +		device_type = "pci";
> +		num-lanes = <4>;
> +		bus-range = <0x0 0xff>;
> +		ranges = <0x81000000 0x0 0x00000000 0x40 0x00010000 0x0 0x00010000   /* downstream I/O */
> +			  0xc2000000 0x0 0x20000000 0x40 0x20000000 0x0 0x20000000   /* prefetchable memory */
> +			  0x82000000 0x0 0x40000000 0x40 0x40000000 0x0 0x40000000>; /* non-prefetchable memory */
> +		#interrupt-cells = <1>;
> +		interrupt-map-mask = <0 0 0 7>;
> +		interrupt-map = <0000 0 0 1 &gic GIC_SPI 91  IRQ_TYPE_LEVEL_HIGH>,
> +				<0000 0 0 2 &gic GIC_SPI 188 IRQ_TYPE_LEVEL_HIGH>,
> +				<0000 0 0 3 &gic GIC_SPI 190 IRQ_TYPE_LEVEL_HIGH>,
> +				<0000 0 0 4 &gic GIC_SPI 192 IRQ_TYPE_LEVEL_HIGH>;
> +	};
> diff --git a/MAINTAINERS b/MAINTAINERS
> index a20df9b..7853d1b 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -6983,6 +6983,16 @@ S:	Maintained
>  F:	Documentation/devicetree/bindings/pci/xgene-pci.txt
>  F:	drivers/pci/host/pci-xgene.c
>  
> +PCIe DRIVER FOR FREESCALE LAYERSCAPE
> +M:	Minghuan Lian <minghuan.Lian@freescale.com>
> +M:	Mingkai Hu <mingkai.hu@freescale.com>
> +M:	Roy Zang <tie-fei.zang@freescale.com>
> +L:	linuxppc-dev@lists.ozlabs.org
> +L:	linux-pci@vger.kernel.org
> +L:	linux-arm-kernel@lists.infradead.org
> +S:	Maintained
> +F:	drivers/pci/host/pci-layerscape.c
> +
>  PCI DRIVER FOR IMX6
>  M:	Richard Zhu <r65037@freescale.com>
>  M:	Lucas Stach <l.stach@pengutronix.de>
> diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig
> index 3dc25fa..8ac69aa 100644
> --- a/drivers/pci/host/Kconfig
> +++ b/drivers/pci/host/Kconfig
> @@ -91,4 +91,12 @@ config PCI_XGENE
>  	  There are 5 internal PCIe ports available. Each port is GEN3 capable
>  	  and have varied lanes from x1 to x8.
>  
> +config PCI_LAYERSCAPE
> +	bool "Freescale Layerscape PCIe controller"
> +	depends on OF
> +	select PCIE_DW
> +	select MFD_SYSCON
> +	help
> +	  Say Y here if you want PCIe controller support on Layerscape SoCs.
> +
>  endmenu
> diff --git a/drivers/pci/host/Makefile b/drivers/pci/host/Makefile
> index 26b3461..44c2699 100644
> --- a/drivers/pci/host/Makefile
> +++ b/drivers/pci/host/Makefile
> @@ -11,3 +11,4 @@ obj-$(CONFIG_PCIE_SPEAR13XX) += pcie-spear13xx.o
>  obj-$(CONFIG_PCI_KEYSTONE) += pci-keystone-dw.o pci-keystone.o
>  obj-$(CONFIG_PCIE_XILINX) += pcie-xilinx.o
>  obj-$(CONFIG_PCI_XGENE) += pci-xgene.o
> +obj-$(CONFIG_PCI_LAYERSCAPE) += pci-layerscape.o
> diff --git a/drivers/pci/host/pci-layerscape.c b/drivers/pci/host/pci-layerscape.c
> new file mode 100644
> index 0000000..6697b1a
> --- /dev/null
> +++ b/drivers/pci/host/pci-layerscape.c
> @@ -0,0 +1,179 @@
> +/*
> + * PCIe host controller driver for Freescale Layerscape SoCs
> + *
> + * Copyright (C) 2014 Freescale Semiconductor.
> + *
> +  * Author: Minghuan Lian <Minghuan.Lian@freescale.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 <linux/kernel.h>
> +#include <linux/delay.h>
> +#include <linux/interrupt.h>
> +#include <linux/module.h>
> +#include <linux/of_pci.h>
> +#include <linux/of_platform.h>
> +#include <linux/of_irq.h>
> +#include <linux/of_address.h>
> +#include <linux/pci.h>
> +#include <linux/platform_device.h>
> +#include <linux/resource.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/regmap.h>
> +
> +#include "pcie-designware.h"
> +
> +/* PEX1/2 Misc Ports Status Register */
> +#define SCFG_PEXMSCPORTSR(pex_idx)	(0x94 + (pex_idx) * 4)
> +#define LTSSM_STATE_SHIFT	20
> +#define LTSSM_STATE_MASK	0x3f
> +#define LTSSM_PCIE_L0		0x11 /* L0 state */
> +
> +/* Symbol Timer Register and Filter Mask Register 1 */
> +#define PCIE_STRFMR1 0x71c
> +
> +struct ls_pcie {
> +	struct list_head node;
> +	struct device *dev;
> +	struct pci_bus *bus;
> +	void __iomem *dbi;
> +	struct regmap *scfg;
> +	struct pcie_port pp;
> +	int index;
> +	int msi_irq;
> +};
> +
> +#define to_ls_pcie(x)	container_of(x, struct ls_pcie, pp)
> +
> +static int ls_pcie_link_up(struct pcie_port *pp)
> +{
> +	u32 state;
> +	struct ls_pcie *pcie = to_ls_pcie(pp);
> +
> +	regmap_read(pcie->scfg, SCFG_PEXMSCPORTSR(pcie->index), &state);
> +	state = (state >> LTSSM_STATE_SHIFT) & LTSSM_STATE_MASK;
> +
> +	if (state < LTSSM_PCIE_L0)
> +		return 0;
> +
> +	return 1;
> +}
> +
> +static void ls_pcie_host_init(struct pcie_port *pp)
> +{
> +	struct ls_pcie *pcie = to_ls_pcie(pp);
> +	int count = 0;
> +	u32 val;
> +
> +	dw_pcie_setup_rc(pp);
> +
> +	while (!ls_pcie_link_up(pp)) {
> +		usleep_range(100, 1000);
> +		count++;
> +		if (count >= 200) {
> +			dev_err(pp->dev, "phy link never came up\n");
> +			return;
> +		}
> +	}
> +
> +	/*
> +	 * LS1021A Workaround for internal TKT228622
> +	 * to fix the INTx hang issue
> +	 */
> +	val = ioread32(pcie->dbi + PCIE_STRFMR1);
> +	val &= 0xffff;
> +	iowrite32(val, pcie->dbi + PCIE_STRFMR1);
> +}
> +
> +static struct pcie_host_ops ls_pcie_host_ops = {
> +	.link_up = ls_pcie_link_up,
> +	.host_init = ls_pcie_host_init,
> +};
> +
> +static int ls_add_pcie_port(struct ls_pcie *pcie)
> +{
> +	struct pcie_port *pp;
> +	int ret;
> +
> +	pp = &pcie->pp;
> +	pp->dev = pcie->dev;
> +	pp->dbi_base = pcie->dbi;
> +	pp->root_bus_nr = -1;
> +	pp->ops = &ls_pcie_host_ops;
> +
> +	ret = dw_pcie_host_init(pp);
> +	if (ret) {
> +		dev_err(pp->dev, "failed to initialize host\n");
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static int __init ls_pcie_probe(struct platform_device *pdev)
> +{
> +	struct ls_pcie *pcie;
> +	struct resource *dbi_base;
> +	u32 index[2];
> +	int ret;
> +
> +	pcie = devm_kzalloc(&pdev->dev, sizeof(*pcie), GFP_KERNEL);
> +	if (!pcie)
> +		return -ENOMEM;
> +
> +	pcie->dev = &pdev->dev;
> +
> +	dbi_base = platform_get_resource_byname(pdev, IORESOURCE_MEM, "regs");
> +	if (!dbi_base) {
> +		dev_err(&pdev->dev, "missing *regs* space\n");
> +		return -ENODEV;
> +	}
> +
> +	pcie->dbi = devm_ioremap_resource(&pdev->dev, dbi_base);
> +	if (IS_ERR(pcie->dbi))
> +		return PTR_ERR(pcie->dbi);
> +
> +	pcie->scfg = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
> +						     "fsl,pcie-scfg");
> +	if (IS_ERR(pcie->scfg)) {
> +		dev_err(&pdev->dev, "No syscfg phandle specified\n");
> +		return PTR_ERR(pcie->scfg);
> +	}
> +
> +	ret = of_property_read_u32_array(pdev->dev.of_node,
> +					 "fsl,pcie-scfg", index, 2);
> +	if (ret)
> +		return ret;
> +	pcie->index = index[1];
> +
> +	ret = ls_add_pcie_port(pcie);
> +	if (ret < 0)
> +		return ret;
> +
> +	platform_set_drvdata(pdev, pcie);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id ls_pcie_of_match[] = {
> +	{ .compatible = "fsl,ls1021a-pcie" },
> +	{ },
> +};
> +MODULE_DEVICE_TABLE(of, ls_pcie_of_match);
> +
> +static struct platform_driver ls_pcie_driver = {
> +	.driver = {
> +		.name = "layerscape-pcie",
> +		.owner = THIS_MODULE,
> +		.of_match_table = ls_pcie_of_match,
> +	},
> +};
> +
> +module_platform_driver_probe(ls_pcie_driver, ls_pcie_probe);
> +
> +MODULE_AUTHOR("Minghuan Lian <Minghuan.Lian@freescale.com>");
> +MODULE_DESCRIPTION("Freescale Layerscape PCIe host controller driver");
> +MODULE_LICENSE("GPL v2");
> -- 
> 1.9.1
>