Re: [PATCH v3 2/2] PCI: sprd: Add support for Unisoc SoCs' PCIe controller

From: Hongtao Wu
Date: Thu Sep 17 2020 - 22:00:54 EST


Hi Bob,
Thanks for the review.

On Wed, Sep 16, 2020 at 1:31 AM Rob Herring <robh@xxxxxxxxxx> wrote:
>
> On Wed, Sep 09, 2020 at 05:48:32PM +0800, Hongtao Wu wrote:
> > From: Hongtao Wu <billows.wu@xxxxxxxxxx>
> >
> > This series adds PCIe controller driver for Unisoc SoCs.
> > This controller is based on DesignWare PCIe IP.
> >
> > Signed-off-by: Hongtao Wu <billows.wu@xxxxxxxxxx>
> > ---
> > drivers/pci/controller/dwc/Kconfig | 13 ++
> > drivers/pci/controller/dwc/Makefile | 1 +
> > drivers/pci/controller/dwc/pcie-sprd.c | 231 +++++++++++++++++++++++++++++++++
> > 3 files changed, 245 insertions(+)
> > create mode 100644 drivers/pci/controller/dwc/pcie-sprd.c
> >
> > diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig
> > index 044a376..0553010 100644
> > --- a/drivers/pci/controller/dwc/Kconfig
> > +++ b/drivers/pci/controller/dwc/Kconfig
> > @@ -311,4 +311,17 @@ config PCIE_AL
> > required only for DT-based platforms. ACPI platforms with the
> > Annapurna Labs PCIe controller don't need to enable this.
> >
> > +
> > +config PCIE_SPRD
> > + tristate "Unisoc PCIe controller - Host Mode"
> > + depends on ARCH_SPRD || COMPILE_TEST
> > + depends on PCI_MSI_IRQ_DOMAIN
> > + select PCIE_DW_HOST
> > + help
> > + Unisoc PCIe controller uses the DesignWare core. It can be configured
> > + as an Endpoint (EP) or a Root complex (RC). In order to enable host
> > + mode (the controller works as RC), PCIE_SPRD must be selected.
> > + Say Y or M here if you want to PCIe RC controller support on Unisoc
> > + SoCs.
> > +
> > endmenu
> > diff --git a/drivers/pci/controller/dwc/Makefile b/drivers/pci/controller/dwc/Makefile
> > index a751553..eb546e9 100644
> > --- a/drivers/pci/controller/dwc/Makefile
> > +++ b/drivers/pci/controller/dwc/Makefile
> > @@ -20,6 +20,7 @@ obj-$(CONFIG_PCI_MESON) += pci-meson.o
> > obj-$(CONFIG_PCIE_TEGRA194) += pcie-tegra194.o
> > obj-$(CONFIG_PCIE_UNIPHIER) += pcie-uniphier.o
> > obj-$(CONFIG_PCIE_UNIPHIER_EP) += pcie-uniphier-ep.o
> > +obj-$(CONFIG_PCIE_SPRD) += pcie-sprd.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-sprd.c b/drivers/pci/controller/dwc/pcie-sprd.c
> > new file mode 100644
> > index 0000000..cec4f34
> > --- /dev/null
> > +++ b/drivers/pci/controller/dwc/pcie-sprd.c
> > @@ -0,0 +1,231 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * PCIe host controller driver for Unisoc SoCs
> > + *
> > + * Copyright (C) 2020 Unisoc, Inc.
> > + *
> > + * Author: Hongtao Wu <Billows.Wu@xxxxxxxxxx>
> > + */
> > +
> > +#include <linux/delay.h>
> > +#include <linux/gpio/consumer.h>
> > +#include <linux/interrupt.h>
> > +#include <linux/mfd/syscon.h>
> > +#include <linux/module.h>
> > +#include <linux/of_device.h>
> > +#include <linux/of_irq.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/property.h>
> > +#include <linux/regmap.h>
> > +
> > +#include "pcie-designware.h"
> > +
> > +#define NUM_OF_ARGS 5
> > +
> > +struct sprd_pcie {
> > + struct dw_pcie pci;
> > +};
> > +
> > +static int sprd_pcie_syscon_setting(struct platform_device *pdev, char *env)
> > +{
> > + struct device_node *np = pdev->dev.of_node;
> > + int i, count, err;
> > + u32 type, delay, reg, mask, val, tmp_val;
> > + struct of_phandle_args out_args;
> > + struct regmap *iomap;
> > + struct device *dev = &pdev->dev;
> > +
> > + if (!of_find_property(np, env, NULL)) {
> > + dev_info(dev, "There isn't property %s in dts\n", env);
> > + return 0;
> > + }
> > +
> > + count = of_property_count_elems_of_size(np, env,
> > + (NUM_OF_ARGS + 1) * sizeof(u32));
> > + dev_info(dev, "Property (%s) reg count is %d :\n", env, count);
> > +
> > + for (i = 0; i < count; i++) {
> > + err = of_parse_phandle_with_fixed_args(np, env, NUM_OF_ARGS,
> > + i, &out_args);
> > + if (err < 0)
> > + return err;
> > +
> > + type = out_args.args[0];
> > + delay = out_args.args[1];
> > + reg = out_args.args[2];
> > + mask = out_args.args[3];
> > + val = out_args.args[4];
> > +
> > + iomap = syscon_node_to_regmap(out_args.np);
> > +
> > + switch (type) {
> > + case 0:
> > + regmap_update_bits(iomap, reg, mask, val);
> > + break;
> > +
> > + case 1:
> > + regmap_read(iomap, reg, &tmp_val);
> > + tmp_val &= (~mask);
> > + tmp_val |= (val & mask);
> > + regmap_write(iomap, reg, tmp_val);
> > + break;
> > + default:
> > + break;
> > + }
> > +
> > + if (delay)
> > + usleep_range(delay, delay + 10);
> > +
> > + regmap_read(iomap, reg, &tmp_val);
> > + dev_dbg(dev,
> > + "%2d:reg[0x%8x] mask[0x%8x] val[0x%8x] result[0x%8x]\n",
> > + i, reg, mask, val, tmp_val);
> > + }
> > +
> > + return i;
> > +}
> > +
> > +static int sprd_pcie_perst_assert(struct platform_device *pdev)
> > +{
> > + return sprd_pcie_syscon_setting(pdev, "sprd,pcie-perst-assert");
>
> Not documented. This should probably use the reset binding.
>

Thanks! I'll Document it in the next version.

> > +}
> > +
> > +static int sprd_pcie_perst_deassert(struct platform_device *pdev)
> > +{
> > + return sprd_pcie_syscon_setting(pdev, "sprd,pcie-perst-deassert");
> > +}
> > +
> > +static int sprd_pcie_power_on(struct platform_device *pdev)
> > +{
> > + int ret;
> > + struct device *dev = &pdev->dev;
> > +
> > + ret = sprd_pcie_syscon_setting(pdev, "sprd,pcie-poweron-syscons");
> > + if (ret < 0)
> > + dev_err(dev,
> > + "failed to set pcie poweroff syscons, return %d\n",
> > + ret);
> > +
> > + sprd_pcie_perst_deassert(pdev);
> > +
> > + return ret;
> > +}
> > +
> > +static int sprd_pcie_power_off(struct platform_device *pdev)
> > +{
> > + int ret;
> > + struct device *dev = &pdev->dev;
> > +
> > + sprd_pcie_perst_assert(pdev);
> > +
> > + ret = sprd_pcie_syscon_setting(pdev, "sprd,pcie-poweroff-syscons");
> > + if (ret < 0)
> > + dev_err(dev,
> > + "failed to set pcie poweroff syscons, return %d\n",
> > + ret);
> > +
> > + return ret;
> > +}
> > +
> > +static int sprd_pcie_host_init(struct pcie_port *pp)
> > +{
> > + int ret;
> > + struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
> > +
> > + dw_pcie_setup_rc(pp);
> > + dw_pcie_msi_init(pp);
> > +
> > + ret = dw_pcie_wait_for_link(pci);
> > + if (ret)
> > + dev_err(pci->dev, "pcie ep may has not been powered on yet\n");
> > +
> > + return ret;
> > +}
> > +
> > +static const struct dw_pcie_host_ops sprd_pcie_host_ops = {
> > + .host_init = sprd_pcie_host_init,
> > +};
> > +
> > +static int sprd_add_pcie_port(struct platform_device *pdev)
> > +{
> > + struct device *dev = &pdev->dev;
> > + struct sprd_pcie *ctrl = platform_get_drvdata(pdev);
> > + struct dw_pcie *pci = &ctrl->pci;
> > + struct pcie_port *pp = &pci->pp;
> > +
> > + pci->dbi_base = devm_platform_ioremap_resource_byname(pdev, "dbi");
> > + if (IS_ERR(pci->dbi_base)) {
> > + dev_err(dev, "failed to get rc dbi base\n");
> > + return PTR_ERR(pci->dbi_base);
> > + }
> > +
> > + pp->ops = &sprd_pcie_host_ops;
> > +
> > + if (IS_ENABLED(CONFIG_PCI_MSI)) {
>
> I don't think this check is needed. The DW core won't setup the MSI if
> not enabled, so doesn't matter if msi_irq is initialized.
>

Thanks!
I'll delete it in the next version.

> > + pp->msi_irq = platform_get_irq_byname(pdev, "msi");
> > + if (pp->msi_irq < 0) {
> > + dev_err(dev, "failed to get msi, return %d\n",
> > + pp->msi_irq);
>
> No need to print an error, the core does this.
>

Thanks!
I'll delete it in the next version.

> > + return pp->msi_irq;
> > + }
> > + }
> > +
> > + return dw_pcie_host_init(pp);
> > +}
> > +
> > +static int sprd_pcie_probe(struct platform_device *pdev)
> > +{
> > + struct device *dev = &pdev->dev;
> > + struct sprd_pcie *ctrl;
> > + struct dw_pcie *pci;
> > + int ret;
> > +
> > + ctrl = devm_kzalloc(dev, sizeof(*ctrl), GFP_KERNEL);
> > + if (!ctrl)
> > + return -ENOMEM;
> > +
> > + pci = &ctrl->pci;
> > + pci->dev = dev;
> > +
> > + platform_set_drvdata(pdev, ctrl);
> > +
> > + ret = sprd_pcie_power_on(pdev);
> > + if (ret < 0) {
> > + dev_err(dev, "failed to get pcie poweron syscons, return %d\n",
> > + ret);
> > + goto err_power_off;
> > + }
> > +
> > + ret = sprd_add_pcie_port(pdev);
> > + if (ret) {
> > + dev_warn(dev, "failed to initialize RC controller\n");
> > + return ret;
> > + }
> > +
> > + return 0;
> > +
> > +err_power_off:
> > + sprd_pcie_power_off(pdev);
> > +
> > + return ret;
> > +}
> > +
> > +static const struct of_device_id sprd_pcie_of_match[] = {
> > + {
> > + .compatible = "sprd,pcie-rc",
> > + },
> > + {},
> > +};
> > +
> > +static struct platform_driver sprd_pcie_driver = {
> > + .probe = sprd_pcie_probe,
>
> You need a .remove hook.
>

Yes! I'll fix it.

> > + .driver = {
> > + .name = "sprd-pcie",
> > + .of_match_table = sprd_pcie_of_match,
> > + },
> > +};
> > +
> > +module_platform_driver(sprd_pcie_driver);
> > +
> > +MODULE_DESCRIPTION("Unisoc PCIe host controller driver");
> > +MODULE_LICENSE("GPL v2");
> > --
> > 2.7.4
> >