Re: [PATCH 08/10] PCI: dwc: artpec6: add support for endpoint mode
From: Kishon Vijay Abraham I
Date: Wed Oct 18 2017 - 04:46:44 EST
Hi Niklas,
On Friday 13 October 2017 09:39 PM, Niklas Cassel wrote:
> Signed-off-by: Niklas Cassel <niklas.cassel@xxxxxxxx>
> ---
> .../devicetree/bindings/pci/axis,artpec6-pcie.txt | 3 +-
> drivers/pci/dwc/Kconfig | 41 +++--
> drivers/pci/dwc/Makefile | 4 +-
> drivers/pci/dwc/pcie-artpec6.c | 202 ++++++++++++++++++++-
> 4 files changed, 233 insertions(+), 17 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/pci/axis,artpec6-pcie.txt b/Documentation/devicetree/bindings/pci/axis,artpec6-pcie.txt
> index 4e4aee4439ea..33eef7ae5a23 100644
> --- a/Documentation/devicetree/bindings/pci/axis,artpec6-pcie.txt
> +++ b/Documentation/devicetree/bindings/pci/axis,artpec6-pcie.txt
> @@ -4,7 +4,8 @@ This PCIe host controller is based on the Synopsys DesignWare PCIe IP
> and thus inherits all the common properties defined in designware-pcie.txt.
>
> Required properties:
> -- compatible: "axis,artpec6-pcie", "snps,dw-pcie"
> +- compatible: "axis,artpec6-pcie", "snps,dw-pcie" for ARTPEC-6 in RC mode;
> + "axis,artpec6-pcie-ep", "snps,dw-pcie" for ARTPEC-6 in EP mode;
If "snps,dw-pcie" is used for both RC and EP mode, how do we differentiate
between the modes?
> - reg: base addresses and lengths of the PCIe controller (DBI),
> the PHY controller, and configuration address space.
> - reg-names: Must include the following entries:
> diff --git a/drivers/pci/dwc/Kconfig b/drivers/pci/dwc/Kconfig
> index 22ec82fcdea2..e333283fb1ed 100644
> --- a/drivers/pci/dwc/Kconfig
> +++ b/drivers/pci/dwc/Kconfig
> @@ -14,6 +14,36 @@ config PCIE_DW_EP
> depends on PCI_ENDPOINT
> select PCIE_DW
>
> +config PCIE_ARTPEC6
> + bool "Axis ARTPEC-6 PCIe controller"
> + depends on (PCI && PCI_MSI_IRQ_DOMAIN) || PCI_ENDPOINT
> + depends on MACH_ARTPEC6
> + help
> + Say Y here to enable PCIe controller support on Axis ARTPEC-6
> + SoCs. This PCIe controller uses the DesignWare core.
> +
> +if PCIE_ARTPEC6
> +
> +config PCIE_ARTPEC6_HOST
> + bool "Axis ARTPEC-6 Host Mode"
> + depends on PCI
> + depends on PCI_MSI_IRQ_DOMAIN
> + select PCIEPORTBUS
> + select PCIE_DW_HOST
> + help
> + Enables support for the PCIe controller in the ARTPEC-6 SoC to work in
> + host mode.
> +
> +config PCIE_ARTPEC6_EP
> + bool "Axis ARTPEC-6 Endpoint Mode"
> + depends on PCI_ENDPOINT
> + select PCIE_DW_EP
> + help
> + Enables support for the PCIe controller in the ARTPEC-6 SoC to work in
> + endpoint mode.
> +
> +endif
> +
> config PCI_DRA7XX
> bool "TI DRA7xx PCIe controller"
> depends on SOC_DRA7XX || COMPILE_TEST
> @@ -148,17 +178,6 @@ config PCIE_ARMADA_8K
> DesignWare hardware and therefore the driver re-uses the
> DesignWare core functions to implement the driver.
>
> -config PCIE_ARTPEC6
> - bool "Axis ARTPEC-6 PCIe controller"
> - depends on PCI
> - depends on MACH_ARTPEC6
> - depends on PCI_MSI_IRQ_DOMAIN
> - select PCIEPORTBUS
> - select PCIE_DW_HOST
> - help
> - Say Y here to enable PCIe controller support on Axis ARTPEC-6
> - SoCs. This PCIe controller uses the DesignWare core.
> -
> config PCIE_KIRIN
> depends on OF && ARM64
> bool "HiSilicon Kirin series SoCs PCIe controllers"
> diff --git a/drivers/pci/dwc/Makefile b/drivers/pci/dwc/Makefile
> index c61be9738cce..ac98242b83a9 100644
> --- a/drivers/pci/dwc/Makefile
> +++ b/drivers/pci/dwc/Makefile
> @@ -2,6 +2,9 @@ obj-$(CONFIG_PCIE_DW) += pcie-designware.o
> obj-$(CONFIG_PCIE_DW_HOST) += pcie-designware-host.o
> obj-$(CONFIG_PCIE_DW_EP) += pcie-designware-ep.o
> obj-$(CONFIG_PCIE_DW_PLAT) += pcie-designware-plat.o
> +ifneq ($(filter y,$(CONFIG_PCIE_ARTPEC6_HOST) $(CONFIG_PCIE_ARTPEC6_EP)),)
> + obj-$(CONFIG_PCIE_ARTPEC6) += pcie-artpec6.o
> +endif
> ifneq ($(filter y,$(CONFIG_PCI_DRA7XX_HOST) $(CONFIG_PCI_DRA7XX_EP)),)
> obj-$(CONFIG_PCI_DRA7XX) += pci-dra7xx.o
> endif
> @@ -12,7 +15,6 @@ obj-$(CONFIG_PCI_KEYSTONE) += pci-keystone-dw.o pci-keystone.o
> obj-$(CONFIG_PCI_LAYERSCAPE) += pci-layerscape.o
> 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_KIRIN) += pcie-kirin.o
>
> # The following drivers are for devices that use the generic ACPI
> diff --git a/drivers/pci/dwc/pcie-artpec6.c b/drivers/pci/dwc/pcie-artpec6.c
> index c5d7f98dc6b2..21ea9ffef784 100644
> --- a/drivers/pci/dwc/pcie-artpec6.c
> +++ b/drivers/pci/dwc/pcie-artpec6.c
> @@ -13,6 +13,7 @@
> #include <linux/delay.h>
> #include <linux/kernel.h>
> #include <linux/init.h>
> +#include <linux/of_device.h>
> #include <linux/pci.h>
> #include <linux/platform_device.h>
> #include <linux/resource.h>
> @@ -30,8 +31,15 @@ struct artpec6_pcie {
> struct dw_pcie *pci;
> struct regmap *regmap; /* DT axis,syscon-pcie */
> void __iomem *phy_base; /* DT phy */
> + enum dw_pcie_device_mode mode;
> };
>
> +struct artpec_pcie_of_data {
> + enum dw_pcie_device_mode mode;
> +};
> +
> +static const struct of_device_id artpec6_pcie_of_match[];
> +
> /* PCIe Port Logic registers (memory-mapped) */
> #define PL_OFFSET 0x700
> #define PCIE_PHY_DEBUG_R0 (PL_OFFSET + 0x28)
> @@ -42,6 +50,7 @@ struct artpec6_pcie {
> #define PCIECFG_DBG_OEN BIT(24)
> #define PCIECFG_CORE_RESET_REQ BIT(21)
> #define PCIECFG_LTSSM_ENABLE BIT(20)
> +#define PCIECFG_DEVICE_TYPE_MASK GENMASK(19, 16)
> #define PCIECFG_CLKREQ_B BIT(11)
> #define PCIECFG_REFCLK_ENABLE BIT(10)
> #define PCIECFG_PLL_ENABLE BIT(9)
> @@ -126,6 +135,16 @@ static void artpec6_pcie_init_phy(struct artpec6_pcie *artpec6_pcie)
> } while (retries && !(val & PHY_COSPLLLOCK));
> }
>
> +static void artpec6_pcie_stop_link(struct dw_pcie *pci)
> +{
> + struct artpec6_pcie *artpec6_pcie = to_artpec6_pcie(pci);
> + u32 val;
> +
> + val = artpec6_pcie_readl(artpec6_pcie, PCIECFG);
> + val &= ~PCIECFG_LTSSM_ENABLE;
> + artpec6_pcie_writel(artpec6_pcie, PCIECFG, val);
> +}
> +
> static int artpec6_pcie_establish_link(struct dw_pcie *pci)
> {
> struct artpec6_pcie *artpec6_pcie = to_artpec6_pcie(pci);
> @@ -195,6 +214,136 @@ static irqreturn_t artpec6_pcie_msi_handler(int irq, void *arg)
> return dw_handle_msi_irq(pp);
> }
>
> +static void dw_pcie_ep_reset_bar(struct dw_pcie *pci, enum pci_barno bar)
> +{
> + u32 reg;
> +
> + reg = PCI_BASE_ADDRESS_0 + (4 * bar);
> + dw_pcie_dbi_ro_wr_en(pci);
> + dw_pcie_writel_dbi2(pci, reg, 0x0);
> + dw_pcie_writel_dbi(pci, reg, 0x0);
> + dw_pcie_dbi_ro_wr_dis(pci);
> +}
> +
> +static void artpec6_pcie_ep_init(struct dw_pcie_ep *ep)
> +{
> + struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
> + struct artpec6_pcie *artpec6_pcie = to_artpec6_pcie(pci);
> + enum pci_barno bar;
> +
> + artpec6_pcie_assert_core_reset(artpec6_pcie);
> + artpec6_pcie_init_phy(artpec6_pcie);
> + artpec6_pcie_deassert_core_reset(artpec6_pcie);
> +
> + for (bar = BAR_0; bar <= BAR_5; bar++)
> + dw_pcie_ep_reset_bar(pci, bar);
> +}
> +
> +static int artpec6_pcie_raise_msi_irq(struct dw_pcie_ep *ep,
> + u8 interrupt_num)
> +{
> + struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
> + struct pci_epc *epc = ep->epc;
> + u32 cap_addr, cap_value, cap_id, next_ptr, msg_ctrl, msg_data;
> + u32 msg_addr_lower, msg_addr_upper;
> + u64 msg_addr;
> + bool has_upper;
> + int ret;
> +
> + /* Raise MSI per the PCI Local Bus Specification Revision 3.0, 6.8.1. */
> + cap_addr = dw_pcie_readl_dbi(pci, PCI_CAPABILITY_LIST);
> + while (1) {
> + cap_value = dw_pcie_readl_dbi(pci, cap_addr);
> + cap_id = cap_value & GENMASK(7, 0);
> + if (cap_id == PCI_CAP_ID_MSI)
> + break;
> + next_ptr = (cap_value & GENMASK(15, 8)) >> 8;
> + if (next_ptr == 0) {
> + dev_err(pci->dev, "No MSI cap found!\n");
> + return -EINVAL;
> + }
> + cap_addr = next_ptr;
> + }
The MSI capability always points to fixed offset in DesingWare. So I don't
think this is necessary unless we move it to the generic endpoint layer.
> + msg_ctrl = (cap_value & GENMASK(31, 16)) >> 16;
> + has_upper = !!(msg_ctrl & BIT(7));
> + msg_addr_lower = dw_pcie_readl_dbi(pci, cap_addr + 0x4);
> + if (has_upper) {
> + msg_addr_upper = dw_pcie_readl_dbi(pci, cap_addr + 0x8);
> + msg_data = dw_pcie_readl_dbi(pci, cap_addr + 0xc) &
> + GENMASK(15, 0);
> + } else {
> + msg_addr_upper = 0;
> + msg_data = dw_pcie_readl_dbi(pci, cap_addr + 0x8) &
> + GENMASK(15, 0);
> + }
> + msg_addr = ((u64) msg_addr_upper) << 32 | msg_addr_lower;
> + ret = epc->ops->map_addr(epc, ep->msi_mem_phys, msg_addr, PAGE_SIZE);
> + if (ret)
> + return ret;
> +
> + writel(msg_data | (interrupt_num - 1), ep->msi_mem);
> +
> + epc->ops->unmap_addr(epc, ep->msi_mem_phys);
> +
> + return 0;
> +}
I think this entire function can also be made as a library function to be used
by other drivers. (looks like only dra7xx has a shortcut to raise MSI irq).
Thanks
Kishon