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Message-ID: <20191219224749.GA4225@google.com>
Date: Thu, 19 Dec 2019 16:47:49 -0600
From: Bjorn Helgaas <helgaas@...nel.org>
To: Kishon Vijay Abraham I <kishon@...com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@....com>,
Rob Herring <robh+dt@...nel.org>,
Arnd Bergmann <arnd@...db.de>,
Andrew Murray <andrew.murray@....com>,
linux-pci@...r.kernel.org, devicetree@...r.kernel.org,
linux-kernel@...r.kernel.org, linux-omap@...r.kernel.org
Subject: Re: [PATCH 11/13] PCI: j721e: Add TI J721E PCIe driver
On Mon, Dec 09, 2019 at 02:51:45PM +0530, Kishon Vijay Abraham I wrote:
> Add support for PCIe controller in J721E SoC. The controller uses the
> Cadence PCIe core programmed by pcie-cadence*.c. The PCIe controller
> will work in both host mode and device mode.
> Some of the features of the controller are:
> *) Supports both RC mode and EP mode
> *) Supports MSI and MSI-X support
> *) Supports upto GEN3 speed mode
> *) Supports SR-IOV capability
> *) Ability to route all transactions via SMMU (support will be added
> in a later patch).
>
> Signed-off-by: Kishon Vijay Abraham I <kishon@...com>
> ---
> drivers/pci/controller/cadence/Kconfig | 23 ++
> drivers/pci/controller/cadence/Makefile | 1 +
> drivers/pci/controller/cadence/pci-j721e.c | 430 +++++++++++++++++++++
> 3 files changed, 454 insertions(+)
> create mode 100644 drivers/pci/controller/cadence/pci-j721e.c
>
> diff --git a/drivers/pci/controller/cadence/Kconfig b/drivers/pci/controller/cadence/Kconfig
> index b76b3cf55ce5..5d30564190e1 100644
> --- a/drivers/pci/controller/cadence/Kconfig
> +++ b/drivers/pci/controller/cadence/Kconfig
> @@ -42,4 +42,27 @@ config PCIE_CADENCE_PLAT_EP
> endpoint mode. This PCIe controller may be embedded into many
> different vendors SoCs.
>
> +config PCI_J721E
> + bool
> +
> +config PCI_J721E_HOST
> + bool "TI J721E PCIe platform host controller"
> + depends on OF
> + select PCIE_CADENCE_HOST
> + select PCI_J721E
> + help
> + Say Y here if you want to support the TI J721E PCIe platform
> + controller in host mode. TI J721E PCIe controller uses Cadence PCIe
> + core.
> +
> +config PCI_J721E_EP
> + bool "TI J721E PCIe platform endpoint controller"
Most drivers call these "PCIe host controller" and "PCIe endpoint
controller" or similar. Does adding "platform" indicate something
useful?
> + depends on OF
> + depends on PCI_ENDPOINT
> + select PCIE_CADENCE_EP
> + select PCI_J721E
> + help
> + Say Y here if you want to support the TI J721E PCIe platform
> + controller in endpoint mode. TI J721E PCIe controller uses Cadence PCIe
> + core.
> endmenu
> diff --git a/drivers/pci/controller/cadence/Makefile b/drivers/pci/controller/cadence/Makefile
> index 232a3f20876a..9bac5fb2f13d 100644
> --- a/drivers/pci/controller/cadence/Makefile
> +++ b/drivers/pci/controller/cadence/Makefile
> @@ -3,3 +3,4 @@ obj-$(CONFIG_PCIE_CADENCE) += pcie-cadence.o
> obj-$(CONFIG_PCIE_CADENCE_HOST) += pcie-cadence-host.o
> obj-$(CONFIG_PCIE_CADENCE_EP) += pcie-cadence-ep.o
> obj-$(CONFIG_PCIE_CADENCE_PLAT) += pcie-cadence-plat.o
> +obj-$(CONFIG_PCI_J721E) += pci-j721e.o
> diff --git a/drivers/pci/controller/cadence/pci-j721e.c b/drivers/pci/controller/cadence/pci-j721e.c
> new file mode 100644
> index 000000000000..9ffb7e88c739
> --- /dev/null
> +++ b/drivers/pci/controller/cadence/pci-j721e.c
> @@ -0,0 +1,430 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/**
> + * pci-j721e - PCIe controller driver for TI's J721E SoCs
> + *
> + * Copyright (C) 2019 Texas Instruments Incorporated - http://www.ti.com
> + * Author: Kishon Vijay Abraham I <kishon@...com>
> + */
> +
> +#include <linux/delay.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/io.h>
> +#include <linux/irqchip/chained_irq.h>
> +#include <linux/irqdomain.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/of_device.h>
> +#include <linux/of_irq.h>
> +#include <linux/pci.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/regmap.h>
> +
> +#include "../../pci.h"
> +#include "pcie-cadence.h"
> +
> +#define J721E_PCIE_USER_CMD_STATUS 0x4
> +#define LINK_TRAINING_ENABLE BIT(0)
> +
> +#define J721E_PCIE_USER_LINKSTATUS 0x14
> +#define LINK_STATUS GENMASK(1, 0)
> +
> +enum link_status {
> + NO_RECIEVERS_DETECTED,
s/NO_RECIEVERS_DETECTED/NO_RECEIVERS_DETECTED/
> + LINK_TRAINING_IN_PROGRESS,
> + LINK_UP_DL_IN_PROGRESS,
> + LINK_UP_DL_COMPLETED,
> +};
> +
> +#define J721E_MODE_RC BIT(7)
> +#define LANE_COUNT_MASK BIT(8)
> +#define LANE_COUNT(n) ((n) << 8)
> +
> +#define GENERATION_SEL_MASK GENMASK(1, 0)
> +
> +#define MAX_LANES 2
> +
> +struct j721e_pcie {
> + struct device *dev;
> + struct device_node *node;
> + u32 mode;
> + u32 num_lanes;
> + struct cdns_pcie *cdns_pcie;
> + void __iomem *user_cfg_base;
> +};
> +
> +enum j721e_pcie_mode {
> + PCI_MODE_RC,
> + PCI_MODE_EP,
> +};
> +
> +struct j721e_pcie_data {
> + enum j721e_pcie_mode mode;
> +};
> +
> +static inline u32 j721e_pcie_user_readl(struct j721e_pcie *pcie, u32 offset)
> +{
> + return readl(pcie->user_cfg_base + offset);
> +}
> +
> +static inline void j721e_pcie_user_writel(struct j721e_pcie *pcie, u32 offset,
> + u32 value)
> +{
> + writel(value, pcie->user_cfg_base + offset);
> +}
> +
> +static int j721e_pcie_start_link(struct cdns_pcie *cdns_pcie, bool start)
> +{
> + struct j721e_pcie *pcie = dev_get_drvdata(cdns_pcie->dev);
> + u32 reg;
> +
> + reg = j721e_pcie_user_readl(pcie, J721E_PCIE_USER_CMD_STATUS);
> + if (start)
> + reg |= LINK_TRAINING_ENABLE;
> + else
> + reg &= ~LINK_TRAINING_ENABLE;
> + j721e_pcie_user_writel(pcie, J721E_PCIE_USER_CMD_STATUS, reg);
> +
> + return 0;
> +}
> +
> +static bool j721e_pcie_is_link_up(struct cdns_pcie *cdns_pcie)
There are many *_pcie_link_up() definitions that looks essentially
like this; maybe this could be simply j721e_pcie_link_up() to match?
> +{
> + struct j721e_pcie *pcie = dev_get_drvdata(cdns_pcie->dev);
> + u32 reg;
> +
> + reg = j721e_pcie_user_readl(pcie, J721E_PCIE_USER_LINKSTATUS);
> + reg &= LINK_STATUS;
> + if (reg == LINK_UP_DL_COMPLETED)
> + return true;
> +
> + return false;
> +}
> +
> +static const struct cdns_pcie_ops j721e_ops_ops = {
> + .read = cdns_pcie_read32,
> + .write = cdns_pcie_write32,
> + .start_link = j721e_pcie_start_link,
> + .is_link_up = j721e_pcie_is_link_up,
> +};
Can these match struct dw_pcie_ops more closely, e.g., ".link_up"
instead of ".is_link_up", ".start_link" and ".stop_link" instead of
".start_link(..., bool)"?
Bjorn
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