Re: [PATCH v3 2/2] PCI: uniphier: Add Socionext UniPhier Pro5 PCIe endpoint controller driver
From: Kunihiko Hayashi
Date: Fri May 08 2020 - 04:32:59 EST
Hi Rob,
Thank you for your comment.
On 2020/05/08 4:33, Rob Herring wrote:
On Mon, Mar 23, 2020 at 06:40:54PM +0900, Kunihiko Hayashi wrote:
Add driver for the Socionext UniPhier Pro5 SoC endpoint controller.
This controller is based on the DesignWare PCIe core.
Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@xxxxxxxxxxxxx>
---
MAINTAINERS | 2 +-
drivers/pci/controller/dwc/Kconfig | 13 +-
drivers/pci/controller/dwc/Makefile | 1 +
drivers/pci/controller/dwc/pcie-uniphier-ep.c | 380 ++++++++++++++++++++++++++
4 files changed, 393 insertions(+), 3 deletions(-)
create mode 100644 drivers/pci/controller/dwc/pcie-uniphier-ep.c
diff --git a/MAINTAINERS b/MAINTAINERS
index 01a4631..95d296b 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -13152,7 +13152,7 @@ M: Kunihiko Hayashi <hayashi.kunihiko@xxxxxxxxxxxxx>
L: linux-pci@xxxxxxxxxxxxxxx
S: Maintained
F: Documentation/devicetree/bindings/pci/uniphier-pcie*.txt
-F: drivers/pci/controller/dwc/pcie-uniphier.c
+F: drivers/pci/controller/dwc/pcie-uniphier*.c
PCIE DRIVER FOR ST SPEAR13XX
M: Pratyush Anand <pratyush.anand@xxxxxxxxx>
diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig
index 169cde5..4dd5ba9 100644
--- a/drivers/pci/controller/dwc/Kconfig
+++ b/drivers/pci/controller/dwc/Kconfig
@@ -282,15 +282,24 @@ config PCIE_TEGRA194_EP
selected. This uses the DesignWare core.
config PCIE_UNIPHIER
- bool "Socionext UniPhier PCIe controllers"
+ bool "Socionext UniPhier PCIe host controllers"
depends on ARCH_UNIPHIER || COMPILE_TEST
depends on OF && HAS_IOMEM
depends on PCI_MSI_IRQ_DOMAIN
select PCIE_DW_HOST
help
- Say Y here if you want PCIe controller support on UniPhier SoCs.
+ Say Y here if you want PCIe host controller support on UniPhier SoCs.
This driver supports LD20 and PXs3 SoCs.
+config PCIE_UNIPHIER_EP
+ bool "Socionext UniPhier PCIe endpoint controllers"
+ depends on ARCH_UNIPHIER || COMPILE_TEST
+ depends on OF && HAS_IOMEM
+ select PCIE_DW_EP
+ help
+ Say Y here if you want PCIe endpoint controller support on
+ UniPhier SoCs. This driver supports Pro5 SoC.
+
config PCIE_AL
bool "Amazon Annapurna Labs PCIe controller"
depends on OF && (ARM64 || COMPILE_TEST)
diff --git a/drivers/pci/controller/dwc/Makefile b/drivers/pci/controller/dwc/Makefile
index 8a637cf..a751553 100644
--- a/drivers/pci/controller/dwc/Makefile
+++ b/drivers/pci/controller/dwc/Makefile
@@ -19,6 +19,7 @@ obj-$(CONFIG_PCIE_HISI_STB) += pcie-histb.o
obj-$(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
# 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-uniphier-ep.c b/drivers/pci/controller/dwc/pcie-uniphier-ep.c
new file mode 100644
index 0000000..71db49f
--- /dev/null
+++ b/drivers/pci/controller/dwc/pcie-uniphier-ep.c
@@ -0,0 +1,380 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PCIe endpoint controller driver for UniPhier SoCs
+ * Copyright 2018 Socionext Inc.
+ * Author: Kunihiko Hayashi <hayashi.kunihiko@xxxxxxxxxxxxx>
+ */
+
+#include <linux/bitops.h>
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/of_device.h>
+#include <linux/pci.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+#include <linux/reset.h>
+
+#include "pcie-designware.h"
+
+/* Link Glue registers */
+#define PCL_RSTCTRL0 0x0010
+#define PCL_RSTCTRL_AXI_REG BIT(3)
+#define PCL_RSTCTRL_AXI_SLAVE BIT(2)
+#define PCL_RSTCTRL_AXI_MASTER BIT(1)
+#define PCL_RSTCTRL_PIPE3 BIT(0)
+
+#define PCL_RSTCTRL1 0x0020
+#define PCL_RSTCTRL_PERST BIT(0)
+
+#define PCL_RSTCTRL2 0x0024
+#define PCL_RSTCTRL_PHY_RESET BIT(0)
+
+#define PCL_MODE 0x8000
+#define PCL_MODE_REGEN BIT(8)
+#define PCL_MODE_REGVAL BIT(0)
+
+#define PCL_APP_CLK_CTRL 0x8004
+#define PCL_APP_CLK_REQ BIT(0)
+
+#define PCL_APP_READY_CTRL 0x8008
+#define PCL_APP_LTSSM_ENABLE BIT(0)
+
+#define PCL_APP_MSI0 0x8040
+#define PCL_APP_VEN_MSI_TC_MASK GENMASK(10, 8)
+#define PCL_APP_VEN_MSI_VECTOR_MASK GENMASK(4, 0)
+
+#define PCL_APP_MSI1 0x8044
+#define PCL_APP_MSI_REQ BIT(0)
+
+#define PCL_APP_INTX 0x8074
+#define PCL_APP_INTX_SYS_INT BIT(0)
+
+/* assertion time of INTx in usec */
+#define PCL_INTX_WIDTH_USEC 30
+
+struct uniphier_pcie_ep_priv {
+ void __iomem *base;
+ struct dw_pcie pci;
+ struct clk *clk, *clk_gio;
+ struct reset_control *rst, *rst_gio;
+ struct phy *phy;
+ const struct pci_epc_features *features;
+};
+
+#define to_uniphier_pcie(x) dev_get_drvdata((x)->dev)
+
+static void uniphier_pcie_ltssm_enable(struct uniphier_pcie_ep_priv *priv,
+ bool enable)
+{
+ u32 val;
+
+ val = readl(priv->base + PCL_APP_READY_CTRL);
+ if (enable)
+ val |= PCL_APP_LTSSM_ENABLE;
+ else
+ val &= ~PCL_APP_LTSSM_ENABLE;
+ writel(val, priv->base + PCL_APP_READY_CTRL);
+}
+
+static void uniphier_pcie_phy_reset(struct uniphier_pcie_ep_priv *priv,
+ bool assert)
+{
+ u32 val;
+
+ val = readl(priv->base + PCL_RSTCTRL2);
+ if (assert)
+ val |= PCL_RSTCTRL_PHY_RESET;
+ else
+ val &= ~PCL_RSTCTRL_PHY_RESET;
+ writel(val, priv->base + PCL_RSTCTRL2);
+}
+
+static void uniphier_pcie_init_ep(struct uniphier_pcie_ep_priv *priv)
+{
+ u32 val;
+
+ /* set EP mode */
+ val = readl(priv->base + PCL_MODE);
+ val |= PCL_MODE_REGEN | PCL_MODE_REGVAL;
+ writel(val, priv->base + PCL_MODE);
+
+ /* clock request */
+ val = readl(priv->base + PCL_APP_CLK_CTRL);
+ val &= ~PCL_APP_CLK_REQ;
+ writel(val, priv->base + PCL_APP_CLK_CTRL);
+
+ /* deassert PIPE3 and AXI reset */
+ val = readl(priv->base + PCL_RSTCTRL0);
+ val |= PCL_RSTCTRL_AXI_REG | PCL_RSTCTRL_AXI_SLAVE
+ | PCL_RSTCTRL_AXI_MASTER | PCL_RSTCTRL_PIPE3;
+ writel(val, priv->base + PCL_RSTCTRL0);
+
+ uniphier_pcie_ltssm_enable(priv, false);
+
+ msleep(100);
+}
+
+static int uniphier_pcie_start_link(struct dw_pcie *pci)
+{
+ struct uniphier_pcie_ep_priv *priv = to_uniphier_pcie(pci);
+
+ uniphier_pcie_ltssm_enable(priv, true);
+
+ return 0;
+}
+
+static void uniphier_pcie_stop_link(struct dw_pcie *pci)
+{
+ struct uniphier_pcie_ep_priv *priv = to_uniphier_pcie(pci);
+
+ uniphier_pcie_ltssm_enable(priv, false);
+}
+
+static void uniphier_pcie_ep_init(struct dw_pcie_ep *ep)
+{
+ struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
+ enum pci_barno bar;
+
+ for (bar = BAR_0; bar <= BAR_5; bar++)
+ dw_pcie_ep_reset_bar(pci, bar);
+}
+
+static int uniphier_pcie_ep_raise_legacy_irq(struct dw_pcie_ep *ep)
+{
+ struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
+ struct uniphier_pcie_ep_priv *priv = to_uniphier_pcie(pci);
+ u32 val;
+
+ /* assert INTx */
+ val = readl(priv->base + PCL_APP_INTX);
+ val |= PCL_APP_INTX_SYS_INT;
+ writel(val, priv->base + PCL_APP_INTX);
+
+ udelay(PCL_INTX_WIDTH_USEC);
What happens if you are preempted here?
If deasserting INTx is postponed, the RC might receive more interrupts
from EP depending on the interrupt setting.
+
+ /* deassert INTx */
+ val &= ~PCL_APP_INTX_SYS_INT;
+ writel(val, priv->base + PCL_APP_INTX);
Any locking needed around this RMWW?
This function is called from pci_epc_raise_irq() via dw_pcie_ep_raise_irq().
In pci_epc_raise_irq(), this is covered with mutex.
Aren't PCI legacy interrupts level triggered and this should only be
cleared when the cause is masked?
This function makes one-shot pulse signal to send INTx to the RC, so this
should be cleared as soon as possible.
+
+ return 0;
+}
+
+static int uniphier_pcie_ep_raise_msi_irq(struct dw_pcie_ep *ep,
+ u8 func_no, u16 interrupt_num)
+{
+ struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
+ struct uniphier_pcie_ep_priv *priv = to_uniphier_pcie(pci);
+ u32 val;
+
+ val = FIELD_PREP(PCL_APP_VEN_MSI_TC_MASK, func_no)
+ | FIELD_PREP(PCL_APP_VEN_MSI_VECTOR_MASK, interrupt_num - 1);
+ writel(val, priv->base + PCL_APP_MSI0);
+
+ val = readl(priv->base + PCL_APP_MSI1);
+ val |= PCL_APP_MSI_REQ;
+ writel(val, priv->base + PCL_APP_MSI1);
+
+ return 0;
+}
+
+static int uniphier_pcie_ep_raise_irq(struct dw_pcie_ep *ep, u8 func_no,
+ enum pci_epc_irq_type type,
+ u16 interrupt_num)
+{
+ struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
+
+ switch (type) {
+ case PCI_EPC_IRQ_LEGACY:
+ return uniphier_pcie_ep_raise_legacy_irq(ep);
+ case PCI_EPC_IRQ_MSI:
+ return uniphier_pcie_ep_raise_msi_irq(ep, func_no,
+ interrupt_num);
+ default:
+ dev_err(pci->dev, "UNKNOWN IRQ type (%d)\n", type);
+ }
+
+ return 0;
+}
+
+static const struct pci_epc_features*
+uniphier_pcie_get_features(struct dw_pcie_ep *ep)
+{
+ struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
+ struct uniphier_pcie_ep_priv *priv = to_uniphier_pcie(pci);
+
+ return priv->features;
+}
+
+static const struct dw_pcie_ep_ops uniphier_pcie_ep_ops = {
+ .ep_init = uniphier_pcie_ep_init,
+ .raise_irq = uniphier_pcie_ep_raise_irq,
+ .get_features = uniphier_pcie_get_features,
+};
+
+static int uniphier_add_pcie_ep(struct uniphier_pcie_ep_priv *priv,
+ struct platform_device *pdev)
+{
+ struct dw_pcie *pci = &priv->pci;
+ struct dw_pcie_ep *ep = &pci->ep;
+ struct device *dev = &pdev->dev;
+ struct resource *res;
+ int ret;
+
+ ep->ops = &uniphier_pcie_ep_ops;
+
+ res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dbi2");
+ pci->dbi_base2 = devm_ioremap_resource(dev, res);
devm_ioremap_resource_byname
Okay, I'll replace with it.
+ if (IS_ERR(pci->dbi_base2))
+ return PTR_ERR(pci->dbi_base2);
+
+ res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "addr_space");
+ if (!res)
+ return -EINVAL;
+
+ ep->phys_base = res->start;
+ ep->addr_size = resource_size(res);
+
+ ret = dw_pcie_ep_init(ep);
+ if (ret)
+ dev_err(dev, "Failed to initialize endpoint (%d)\n", ret);
+
+ return ret;
+}
+
+static int uniphier_pcie_ep_enable(struct uniphier_pcie_ep_priv *priv)
+{
+ int ret;
+
+ ret = clk_prepare_enable(priv->clk);
+ if (ret)
+ return ret;
+
+ ret = clk_prepare_enable(priv->clk_gio);
+ if (ret)
+ goto out_clk_disable;
+
+ ret = reset_control_deassert(priv->rst);
+ if (ret)
+ goto out_clk_gio_disable;
+
+ ret = reset_control_deassert(priv->rst_gio);
+ if (ret)
+ goto out_rst_assert;
+
+ uniphier_pcie_init_ep(priv);
+
+ uniphier_pcie_phy_reset(priv, true);
+
+ ret = phy_init(priv->phy);
+ if (ret)
+ goto out_rst_gio_assert;
+
+ uniphier_pcie_phy_reset(priv, false);
+
+ return 0;
+
+out_rst_gio_assert:
+ reset_control_assert(priv->rst_gio);
+out_rst_assert:
+ reset_control_assert(priv->rst);
+out_clk_gio_disable:
+ clk_disable_unprepare(priv->clk_gio);
+out_clk_disable:
+ clk_disable_unprepare(priv->clk);
+
+ return ret;
+}
+
+static const struct dw_pcie_ops dw_pcie_ops = {
+ .start_link = uniphier_pcie_start_link,
+ .stop_link = uniphier_pcie_stop_link,
+};
+
+static int uniphier_pcie_ep_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct uniphier_pcie_ep_priv *priv;
+ struct resource *res;
+ int ret;
+
+ priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->features = of_device_get_match_data(dev);
+ if (WARN_ON(!priv->features))
+ return -EINVAL;
+
+ priv->pci.dev = dev;
+ priv->pci.ops = &dw_pcie_ops;
+
+ res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dbi");
+ priv->pci.dbi_base = devm_pci_remap_cfg_resource(dev, res);
+ if (IS_ERR(priv->pci.dbi_base))
+ return PTR_ERR(priv->pci.dbi_base);
+
+ res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "link");
+ priv->base = devm_ioremap_resource(dev, res);
devm_ioremap_resource_byname()
Ditto.
+ if (IS_ERR(priv->base))
+ return PTR_ERR(priv->base);
+
+ priv->clk_gio = devm_clk_get(dev, "gio");
+ if (IS_ERR(priv->clk))
+ return PTR_ERR(priv->clk);
+
+ priv->rst_gio = devm_reset_control_get_shared(dev, "gio");
+ if (IS_ERR(priv->rst_gio))
+ return PTR_ERR(priv->rst_gio);
+
+ priv->clk = devm_clk_get(dev, "link");
+ if (IS_ERR(priv->clk))
+ return PTR_ERR(priv->clk);
+
+ priv->rst = devm_reset_control_get_shared(dev, "link");
+ if (IS_ERR(priv->rst))
+ return PTR_ERR(priv->rst);
+
+ priv->phy = devm_phy_optional_get(dev, "pcie-phy");
+ if (IS_ERR(priv->phy)) {
+ ret = PTR_ERR(priv->phy);
+ dev_err(dev, "Failed to get phy (%d)\n", ret);
+ return ret;
+ }
+
+ platform_set_drvdata(pdev, priv);
+
+ ret = uniphier_pcie_ep_enable(priv);
+ if (ret)
+ return ret;
+
+ return uniphier_add_pcie_ep(priv, pdev);
+}
+
+static const struct pci_epc_features uniphier_pro5_data = {
+ .linkup_notifier = false,
+ .msi_capable = true,
+ .msix_capable = false,
+ .align = 1 << 16,
+ .bar_fixed_64bit = BIT(BAR_0) | BIT(BAR_2) | BIT(BAR_4),
+ .reserved_bar = BIT(BAR_4),
+};
+
+static const struct of_device_id uniphier_pcie_ep_match[] = {
+ {
+ .compatible = "socionext,uniphier-pro5-pcie-ep",
+ .data = &uniphier_pro5_data,
+ },
+ { /* sentinel */ },
+};
+
+static struct platform_driver uniphier_pcie_ep_driver = {
+ .probe = uniphier_pcie_ep_probe,
+ .driver = {
+ .name = "uniphier-pcie-ep",
+ .of_match_table = uniphier_pcie_ep_match,
+ .suppress_bind_attrs = true,
+ },
+};
+builtin_platform_driver(uniphier_pcie_ep_driver);
Why not a module?
This controller is based on DesignWare Core IP, and this driver is also
based on pcie-designware-ep.c. Since this dwc driver doesn't have a remove
function, like the UniPhier PCIe host drivers, I think it's hard to finalize
the controller safely.
Thank you,
---
Best Regards
Kunihiko Hayashi