On Wed, Dec 02, 2020 at 03:31:56PM +0800, Wan Ahmad Zainie wrote:
> Add driver for Intel Keem Bay SoC PCIe controller. This controller
> is based on DesignWare PCIe core.
>
> In root complex mode, only internal reference clock is possible for
> Keem Bay A0. For Keem Bay B0, external reference clock can be used
> and will be the default configuration. Currently, keembay_pcie_of_data
> structure has one member. It will be expanded later to handle this
> difference.
>
> Endpoint mode link initialization is handled by the boot firmware.
>
> Signed-off-by: Wan Ahmad Zainie <wan.ahmad.zainie.wan.mohamad@xxxxxxxxx>
> Acked-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> ---
> drivers/pci/controller/dwc/Kconfig | 24 ++
> drivers/pci/controller/dwc/Makefile | 1 +
> drivers/pci/controller/dwc/pcie-keembay.c | 500 ++++++++++++++++++++++
> 3 files changed, 525 insertions(+)
> create mode 100644 drivers/pci/controller/dwc/pcie-keembay.c
>
> diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig
> index bc049865f8e0..2aab8f9872c7 100644
> --- a/drivers/pci/controller/dwc/Kconfig
> +++ b/drivers/pci/controller/dwc/Kconfig
> @@ -219,6 +219,30 @@ config PCIE_INTEL_GW
> The PCIe controller uses the DesignWare core plus Intel-specific
> hardware wrappers.
>
> +config PCIE_KEEMBAY
> + bool
> +
> +config PCIE_KEEMBAY_HOST
> + bool "Intel Keem Bay PCIe controller - Host mode"
> + depends on ARCH_KEEMBAY || COMPILE_TEST
> + depends on PCI && PCI_MSI_IRQ_DOMAIN
> + select PCIE_DW_HOST
> + select PCIE_KEEMBAY
> + help
> + Say Y here to enable support for the PCIe controller in Keem Bay
> + to work in host mode. This uses the DesignWare core.
> +
> +config PCIE_KEEMBAY_EP
> + bool "Intel Keem Bay PCIe controller - Endpoint mode"
> + depends on ARCH_KEEMBAY || COMPILE_TEST
> + depends on PCI && PCI_MSI_IRQ_DOMAIN
> + depends on PCI_ENDPOINT
> + select PCIE_DW_EP
> + select PCIE_KEEMBAY
> + help
> + Say Y here to enable support for the PCIe controller in Keem Bay
> + to work in endpoint mode. This uses the DesignWare core.
> +
> config PCIE_KIRIN
> depends on OF && (ARM64 || COMPILE_TEST)
> bool "HiSilicon Kirin series SoCs PCIe controllers"
> diff --git a/drivers/pci/controller/dwc/Makefile b/drivers/pci/controller/dwc/Makefile
> index a751553fa0db..95da2c62c426 100644
> --- a/drivers/pci/controller/dwc/Makefile
> +++ b/drivers/pci/controller/dwc/Makefile
> @@ -14,6 +14,7 @@ obj-$(CONFIG_PCIE_QCOM) += pcie-qcom.o
> obj-$(CONFIG_PCIE_ARMADA_8K) += pcie-armada8k.o
> obj-$(CONFIG_PCIE_ARTPEC6) += pcie-artpec6.o
> obj-$(CONFIG_PCIE_INTEL_GW) += pcie-intel-gw.o
> +obj-$(CONFIG_PCIE_KEEMBAY) += pcie-keembay.o
> obj-$(CONFIG_PCIE_KIRIN) += pcie-kirin.o
> obj-$(CONFIG_PCIE_HISI_STB) += pcie-histb.o
> obj-$(CONFIG_PCI_MESON) += pci-meson.o
> diff --git a/drivers/pci/controller/dwc/pcie-keembay.c b/drivers/pci/controller/dwc/pcie-keembay.c
> new file mode 100644
> index 000000000000..71978c8bf8c6
> --- /dev/null
> +++ b/drivers/pci/controller/dwc/pcie-keembay.c
> @@ -0,0 +1,500 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * PCIe controller driver for Intel Keem Bay
> + * Copyright (C) 2020 Intel Corporation
> + */
> +
> +#include <linux/bitfield.h>
> +#include <linux/bits.h>
> +#include <linux/clk.h>
> +#include <linux/delay.h>
> +#include <linux/err.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/init.h>
> +#include <linux/iopoll.h>
> +#include <linux/kernel.h>
> +#include <linux/mod_devicetable.h>
> +#include <linux/pci.h>
> +#include <linux/platform_device.h>
> +#include <linux/property.h>
> +
> +#include "pcie-designware.h"
> +
> +/* PCIE_REGS_APB_SLV Registers */
> +#define PCIE_REGS_PCIE_CFG 0x0004
> +#define PCIE_DEVICE_TYPE BIT(8)
> +#define PCIE_RSTN BIT(0)
> +#define PCIE_REGS_PCIE_APP_CNTRL 0x0008
> +#define APP_LTSSM_ENABLE BIT(0)
> +
> +#define PCIE_REGS_PCIE_INTR_ENABLE 0x0018
> +#define LBC_CII_EVENT_EN BIT(18)
> +#define PCIE_REGS_PCIE_INTR_FLAGS 0x001c
> +#define PCIE_REGS_PCIE_ERR_INTR_ENABLE 0x0020
> +#define LINK_REQ_RST_EN BIT(15)
> +#define PCIE_REGS_PCIE_ERR_INTR_FLAGS 0x0024
> +#define PCIE_REGS_INTERRUPT_ENABLE 0x0028
> +#define MSI_CTRL_INT_EN BIT(8)
> +#define EDMA_INT_EN GENMASK(7, 0)
> +#define PCIE_REGS_INTERRUPT_STATUS 0x002c
> +#define MSI_CTRL_INT BIT(8)
> +
> +#define PCIE_REGS_PCIE_SII_PM_STATE 0x00b0
> +#define SMLH_LINK_UP BIT(19)
> +#define RDLH_LINK_UP BIT(8)
> +#define PCIE_REGS_PCIE_SII_LINK_UP (SMLH_LINK_UP | RDLH_LINK_UP)
> +#define PCIE_REGS_PCIE_PHY_CNTL 0x0164
> +#define PHY0_SRAM_BYPASS BIT(8)
> +#define PCIE_REGS_PCIE_PHY_STAT 0x0168
> +#define PHY0_MPLLA_STATE BIT(1)
> +#define PCIE_REGS_LJPLL_STA 0x016c
> +#define LJPLL_LOCK BIT(0)
> +#define PCIE_REGS_LJPLL_CNTRL_0 0x0170
> +#define LJPLL_EN BIT(29)
> +#define LJPLL_FOUT_EN GENMASK(24, 21)
> +#define PCIE_REGS_LJPLL_CNTRL_2 0x0178
> +#define LJPLL_REF_DIV GENMASK(17, 12)
> +#define LJPLL_FB_DIV GENMASK(11, 0)
> +#define PCIE_REGS_LJPLL_CNTRL_3 0x017c
> +#define LJPLL_POST_DIV3A GENMASK(24, 22)
> +#define LJPLL_POST_DIV2A GENMASK(18, 16)
> +
> +#define PCIE_REGS_MEM_ACCESS_IRQ_ENABLE 0x0184
> +#define MEM_ACCESS_IRQ_ENABLE GENMASK(31, 0)
> +
> +#define PERST_DELAY_US 1000
> +#define AUX_CLK_RATE_HZ 24000000
> +
> +struct keembay_pcie {
> + struct dw_pcie pci;
> + void __iomem *apb_base;
> + enum dw_pcie_device_mode mode;
> +
> + struct clk *clk_master;
> + struct clk *clk_aux;
> + struct gpio_desc *reset;
> +};
> +
> +struct keembay_pcie_of_data {
> + enum dw_pcie_device_mode mode;
> +};
> +
> +static inline u32 keembay_pcie_readl(struct keembay_pcie *pcie, u32 offset)
> +{
> + return readl(pcie->apb_base + offset);
> +}
> +
> +static inline void keembay_pcie_writel(struct keembay_pcie *pcie, u32 offset,
> + u32 value)
> +{
> + writel(value, pcie->apb_base + offset);
> +}
I'd prefer to get rid of these pointless wrappers. Also, if ordering WRT
to DMA is not needed, use _relaxed variants.
> +
> +static void keembay_ep_reset_assert(struct keembay_pcie *pcie)
> +{
> + gpiod_set_value_cansleep(pcie->reset, 1);
> + usleep_range(PERST_DELAY_US, PERST_DELAY_US + 500);
> +}
> +
> +static void keembay_ep_reset_deassert(struct keembay_pcie *pcie)
> +{
> + msleep(100);
> +
> + gpiod_set_value_cansleep(pcie->reset, 0);
> + usleep_range(PERST_DELAY_US, PERST_DELAY_US + 500);
> +}
> +
> +static void keembay_pcie_ltssm_enable(struct keembay_pcie *pcie, bool enable)
> +{
> + u32 val;
> +
> + val = keembay_pcie_readl(pcie, PCIE_REGS_PCIE_APP_CNTRL);
> + if (enable)
> + val |= APP_LTSSM_ENABLE;
> + else
> + val &= ~APP_LTSSM_ENABLE;
> + keembay_pcie_writel(pcie, PCIE_REGS_PCIE_APP_CNTRL, val);
If this is the only bit in this register, do you really need RMW?
> +}
> +
> +static int keembay_pcie_link_up(struct dw_pcie *pci)
> +{
> + struct keembay_pcie *pcie = dev_get_drvdata(pci->dev);
> + u32 val;
> +
> + val = keembay_pcie_readl(pcie, PCIE_REGS_PCIE_SII_PM_STATE);
> +
> + return (val & PCIE_REGS_PCIE_SII_LINK_UP) == PCIE_REGS_PCIE_SII_LINK_UP;
> +}
> +
> +static int keembay_pcie_start_link(struct dw_pcie *pci)
> +{
> + struct keembay_pcie *pcie = dev_get_drvdata(pci->dev);
> + u32 val;
> + int ret;
> +
> + if (pcie->mode == DW_PCIE_EP_TYPE)
> + return 0;
> +
> + keembay_pcie_ltssm_enable(pcie, false);
> +
> + ret = readl_poll_timeout(pcie->apb_base + PCIE_REGS_PCIE_PHY_STAT,
> + val, val & PHY0_MPLLA_STATE, 20,
> + 500 * USEC_PER_MSEC);
> + if (ret) {
> + dev_err(pci->dev, "MPLLA is not locked\n");
> + return ret;
> + }
> +
> + keembay_pcie_ltssm_enable(pcie, true);
> +
> + return 0;
> +}
> +
> +static void keembay_pcie_stop_link(struct dw_pcie *pci)
> +{
> + struct keembay_pcie *pcie = dev_get_drvdata(pci->dev);
> +
> + keembay_pcie_ltssm_enable(pcie, false);
> +}
> +
> +static const struct dw_pcie_ops keembay_pcie_ops = {
> + .link_up = keembay_pcie_link_up,
> + .start_link = keembay_pcie_start_link,
> + .stop_link = keembay_pcie_stop_link,
> +};
> +
> +static inline struct clk *keembay_pcie_probe_clock(struct device *dev,
> + const char *id, u64 rate)
> +{
> + struct clk *clk;
> + int ret;
> +
> + clk = devm_clk_get(dev, id);
> + if (IS_ERR(clk))
> + return clk;
> +
> + if (rate) {
> + ret = clk_set_rate(clk, rate);
> + if (ret)
> + return ERR_PTR(ret);
> + }
> +
> + ret = clk_prepare_enable(clk);
> + if (ret)
> + return ERR_PTR(ret);
> +
> + ret = devm_add_action_or_reset(dev,
> + (void(*)(void *))clk_disable_unprepare,
> + clk);
> + if (ret)
> + return ERR_PTR(ret);
> +
> + return clk;
> +}
> +
> +static int keembay_pcie_probe_clocks(struct keembay_pcie *pcie)
> +{
> + struct dw_pcie *pci = &pcie->pci;
> + struct device *dev = pci->dev;
> +
> + pcie->clk_master = keembay_pcie_probe_clock(dev, "master", 0);
> + if (IS_ERR(pcie->clk_master))
> + return dev_err_probe(dev, PTR_ERR(pcie->clk_master),
> + "Failed to enable master clock");
> +
> + pcie->clk_aux = keembay_pcie_probe_clock(dev, "aux", AUX_CLK_RATE_HZ);
> + if (IS_ERR(pcie->clk_aux))
> + return dev_err_probe(dev, PTR_ERR(pcie->clk_aux),
> + "Failed to enable auxiliary clock");
> +
> + return 0;
> +}
> +
> +/*
> + * Initialize the internal PCIe PLL in Host mode.
> + * See the following sections in Keem Bay data book,
> + * (1) 6.4.6.1 PCIe Subsystem Example Initialization,
> + * (2) 6.8 PCIe Low Jitter PLL for Ref Clk Generation.
> + */
> +static int keembay_pcie_pll_init(struct keembay_pcie *pcie)
> +{
> + struct dw_pcie *pci = &pcie->pci;
> + u32 val;
> + int ret;
> +
> + val = FIELD_PREP(LJPLL_REF_DIV, 0) | FIELD_PREP(LJPLL_FB_DIV, 0x32);
> + keembay_pcie_writel(pcie, PCIE_REGS_LJPLL_CNTRL_2, val);
> +
> + val = FIELD_PREP(LJPLL_POST_DIV3A, 0x2) |
> + FIELD_PREP(LJPLL_POST_DIV2A, 0x2);
> + keembay_pcie_writel(pcie, PCIE_REGS_LJPLL_CNTRL_3, val);
> +
> + val = FIELD_PREP(LJPLL_EN, 0x1) | FIELD_PREP(LJPLL_FOUT_EN, 0xc);
> + keembay_pcie_writel(pcie, PCIE_REGS_LJPLL_CNTRL_0, val);
> +
> + ret = readl_poll_timeout(pcie->apb_base + PCIE_REGS_LJPLL_STA,
> + val, val & LJPLL_LOCK, 20,
> + 500 * USEC_PER_MSEC);
> + if (ret)
> + dev_err(pci->dev, "Low jitter PLL is not locked\n");
> +
> + return ret;
> +}
> +
> +static irqreturn_t keembay_pcie_irq_handler(int irq, void *arg)
> +{
> + struct keembay_pcie *pcie = arg;
> + struct dw_pcie *pci = &pcie->pci;
> + struct pcie_port *pp = &pci->pp;
> + u32 val, mask, status;
> +
> + val = keembay_pcie_readl(pcie, PCIE_REGS_INTERRUPT_STATUS);
> + mask = keembay_pcie_readl(pcie, PCIE_REGS_INTERRUPT_ENABLE);
> +
> + status = val & mask;
> + if (!status)
> + return IRQ_NONE;
> +
> + if (status & MSI_CTRL_INT)
> + dw_handle_msi_irq(pp);
> +
> + keembay_pcie_writel(pcie, PCIE_REGS_INTERRUPT_STATUS, status);
> +
> + return IRQ_HANDLED;
> +}
> +
> +static int keembay_pcie_setup_irq(struct keembay_pcie *pcie)
> +{
> +
> + struct dw_pcie *pci = &pcie->pci;
> + struct device *dev = pci->dev;
> + struct platform_device *pdev = to_platform_device(dev);
> + int irq, ret;
> +
> + irq = platform_get_irq_byname(pdev, "pcie");
> + if (irq < 0)
> + return irq;
> +
> + ret = devm_request_irq(dev, irq, keembay_pcie_irq_handler,
> + IRQF_SHARED | IRQF_NO_THREAD, "pcie", pcie);
> + if (ret) {
> + dev_err(dev, "Failed to request IRQ: %d\n", ret);
> + return ret;
> + }
> +
> + irq = platform_get_irq_byname(pdev, "pcie_ev");
> + if (irq < 0)
> + return irq;
> +
> + irq = platform_get_irq_byname(pdev, "pcie_err");
> + if (irq < 0)
> + return irq;
> +
> + if (pcie->mode == DW_PCIE_EP_TYPE) {
> + irq = platform_get_irq_byname(pdev, "pcie_mem_access");
> + if (irq < 0)
> + return irq;
> + }
This is all dead code as you don't do anything with the irqs.
> +
> + return 0;
> +}
> +
> +static void keembay_pcie_ep_init(struct dw_pcie_ep *ep)
> +{
> + struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
> + struct keembay_pcie *pcie = dev_get_drvdata(pci->dev);
> + u32 val;
> +
> + val = keembay_pcie_readl(pcie, PCIE_REGS_INTERRUPT_ENABLE);
> + keembay_pcie_writel(pcie, PCIE_REGS_INTERRUPT_ENABLE,
> + val | EDMA_INT_EN);
So you leave any other interrupts enabled which might already be
enabled? Better to initialize to known state.
> +
> + val = keembay_pcie_readl(pcie, PCIE_REGS_PCIE_INTR_ENABLE);
> + keembay_pcie_writel(pcie, PCIE_REGS_PCIE_INTR_ENABLE,
> + val | LBC_CII_EVENT_EN);
> +
> + val = keembay_pcie_readl(pcie, PCIE_REGS_PCIE_ERR_INTR_ENABLE);
> + keembay_pcie_writel(pcie, PCIE_REGS_PCIE_ERR_INTR_ENABLE,
> + val | LINK_REQ_RST_EN);
> +
> + keembay_pcie_writel(pcie, PCIE_REGS_MEM_ACCESS_IRQ_ENABLE,
> + MEM_ACCESS_IRQ_ENABLE);
> +}
> +
> +static int keembay_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:
> + /* Legacy interrupts are not supported in Keem Bay */
> + dev_err(pci->dev, "Legacy IRQ is not supported\n");
> + return -EINVAL;
> + case PCI_EPC_IRQ_MSI:
> + return dw_pcie_ep_raise_msi_irq(ep, func_no, interrupt_num);
> + case PCI_EPC_IRQ_MSIX:
> + return dw_pcie_ep_raise_msix_irq(ep, func_no, interrupt_num);
> + default:
> + dev_err(pci->dev, "Unknown IRQ type %d\n", type);
> + return -EINVAL;
> + }
Doesn't the lack of a 'return' give a warning?
> +}
> +
> +static const struct pci_epc_features keembay_pcie_epc_features = {
> + .linkup_notifier = false,
> + .msi_capable = true,
> + .msix_capable = true,
> + .reserved_bar = BIT(BAR_1) | BIT(BAR_3) | BIT(BAR_5),
> + .bar_fixed_64bit = BIT(BAR_0) | BIT(BAR_2) | BIT(BAR_4),
> + .align = SZ_16K,
> +};
> +
> +static const struct pci_epc_features *
> +keembay_pcie_get_features(struct dw_pcie_ep *ep)
> +{
> + return &keembay_pcie_epc_features;
> +}
> +
> +static const struct dw_pcie_ep_ops keembay_pcie_ep_ops = {
> + .ep_init = keembay_pcie_ep_init,
> + .raise_irq = keembay_pcie_ep_raise_irq,
> + .get_features = keembay_pcie_get_features,
> +};
> +
> +static const struct dw_pcie_host_ops keembay_pcie_host_ops = {
> +};
> +
> +static int keembay_pcie_add_pcie_port(struct keembay_pcie *pcie,
> + struct platform_device *pdev)
> +{
> + struct dw_pcie *pci = &pcie->pci;
> + struct pcie_port *pp = &pci->pp;
> + struct device *dev = &pdev->dev;
> + u32 val;
> + int ret;
> +
> + pp->ops = &keembay_pcie_host_ops;
> + pp->msi_irq = -ENODEV;
> +
> + pcie->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
> + if (IS_ERR(pcie->reset))
> + return PTR_ERR(pcie->reset);
> +
> + ret = keembay_pcie_probe_clocks(pcie);
> + if (ret)
> + return ret;
> +
> + val = keembay_pcie_readl(pcie, PCIE_REGS_PCIE_PHY_CNTL);
> + val |= PHY0_SRAM_BYPASS;
> + keembay_pcie_writel(pcie, PCIE_REGS_PCIE_PHY_CNTL, val);
> +
> + keembay_pcie_writel(pcie, PCIE_REGS_PCIE_CFG, PCIE_DEVICE_TYPE);
> +
> + ret = keembay_pcie_pll_init(pcie);
> + if (ret)
> + return ret;
> +
> + val = keembay_pcie_readl(pcie, PCIE_REGS_PCIE_CFG);
> + keembay_pcie_writel(pcie, PCIE_REGS_PCIE_CFG, val | PCIE_RSTN);
> +
> + keembay_ep_reset_deassert(pcie);
> +
> + ret = dw_pcie_host_init(pp);
> + if (ret) {
> + keembay_ep_reset_assert(pcie);
> + dev_err(dev, "Failed to initialize host: %d\n", ret);
> + return ret;
> + }
> +
> + val = keembay_pcie_readl(pcie, PCIE_REGS_INTERRUPT_ENABLE);
> + if (IS_ENABLED(CONFIG_PCI_MSI))
> + val |= MSI_CTRL_INT_EN;
> + keembay_pcie_writel(pcie, PCIE_REGS_INTERRUPT_ENABLE, val);
> +
> + return 0;
> +}
> +
> +static int keembay_pcie_probe(struct platform_device *pdev)
> +{
> + const struct keembay_pcie_of_data *data;
> + struct device *dev = &pdev->dev;
> + struct keembay_pcie *pcie;
> + struct dw_pcie *pci;
> + enum dw_pcie_device_mode mode;
> + int ret;
> +
> + data = device_get_match_data(dev);
> + if (!data)
> + return -ENODEV;
> +
> + mode = (enum dw_pcie_device_mode)data->mode;
> +
> + pcie = devm_kzalloc(dev, sizeof(*pcie), GFP_KERNEL);
> + if (!pcie)
> + return -ENOMEM;
> +
> + pci = &pcie->pci;
> + pci->dev = dev;
> + pci->ops = &keembay_pcie_ops;
> +
> + pcie->mode = mode;
> +
> + pcie->apb_base = devm_platform_ioremap_resource_byname(pdev, "apb");
> + if (IS_ERR(pcie->apb_base))
> + return PTR_ERR(pcie->apb_base);
> +
> + ret = keembay_pcie_setup_irq(pcie);
> + if (ret)
> + return ret;
> +
> + platform_set_drvdata(pdev, pcie);
> +
> + switch (pcie->mode) {
> + case DW_PCIE_RC_TYPE:
> + if (!IS_ENABLED(CONFIG_PCIE_KEEMBAY_HOST))
> + return -ENODEV;
> +
> + return keembay_pcie_add_pcie_port(pcie, pdev);
> + case DW_PCIE_EP_TYPE:
> + if (!IS_ENABLED(CONFIG_PCIE_KEEMBAY_EP))
> + return -ENODEV;
> +
> + pci->ep.ops = &keembay_pcie_ep_ops;
> + return dw_pcie_ep_init(&pci->ep);
> + default:
> + dev_err(dev, "Invalid device type %d\n", pcie->mode);
> + return -ENODEV;
> + }
> +}
> +
> +static const struct keembay_pcie_of_data keembay_pcie_rc_of_data = {
> + .mode = DW_PCIE_RC_TYPE,
> +};
> +
> +static const struct keembay_pcie_of_data keembay_pcie_ep_of_data = {
> + .mode = DW_PCIE_EP_TYPE,
> +};
> +
> +static const struct of_device_id keembay_pcie_of_match[] = {
> + {
> + .compatible = "intel,keembay-pcie",
> + .data = &keembay_pcie_rc_of_data,
> + },
> + {
> + .compatible = "intel,keembay-pcie-ep",
> + .data = &keembay_pcie_ep_of_data,
> + },
> + {}
> +};
> +
> +static struct platform_driver keembay_pcie_driver = {
> + .driver = {
> + .name = "keembay-pcie",
> + .of_match_table = keembay_pcie_of_match,
> + .suppress_bind_attrs = true,
> + },
> + .probe = keembay_pcie_probe,
> +};
> +builtin_platform_driver(keembay_pcie_driver);
> --
> 2.17.1
>
