Re: [PATCH v7 6/6] PCI: spacemit-k1: Add Spacemit K3 PCIe host controller support
From: Manivannan Sadhasivam
Date: Tue Oct 27 2026 - 04:01:19 EST
On 2026-10-21 13:56 +0530, Siddharth Vadapalli wrote:
> On 10/21/26 1:26 PM, Inochi Amaoto wrote:
> > On Sun, Oct 18, 2026 at 06:05:39PM +0530, Manivannan Sadhasivam wrote:
> >> On 2026-09-29 16:37 +0800, Inochi Amaoto wrote:
> >>> The PCIe controller on Spacemit K3 is almost a standard Synopsys
> >>> DesignWare PCIe IP with extra link and reset control. Unlike
> >>> the PCIe controller on K1, this controller supports external MSI
> >>> interrupt controller and can use multiple PHYs at the same time.
> >>>
> >>> Add driver to support PCIe controller on Spacemit K3 PCIe.
> >>>
> >>> Signed-off-by: Inochi Amaoto <inochiama@xxxxxxxxx>
> >>> ---
> >>> drivers/pci/controller/dwc/Kconfig | 4 +-
> >>> drivers/pci/controller/dwc/pcie-spacemit-k1.c | 139 ++++++++++++++++++
> >>> 2 files changed, 141 insertions(+), 2 deletions(-)
> >>>
> >>> diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig
> >>> index dcfbe7e229fd..f9c27165260e 100644
> >>> --- a/drivers/pci/controller/dwc/Kconfig
> >>> +++ b/drivers/pci/controller/dwc/Kconfig
> >>> @@ -443,7 +443,7 @@ config PCIE_SOPHGO_DW
> >>> Sophgo SoCs.
> >>>
> >>> config PCIE_SPACEMIT_K1
> >>> - tristate "SpacemiT K1 PCIe controller (host mode)"
> >>> + tristate "SpacemiT PCIe controller (host mode)"
> >>> depends on ARCH_SPACEMIT || COMPILE_TEST
> >>> depends on HAS_IOMEM
> >>> select PCIE_DW_HOST
> >>> @@ -451,7 +451,7 @@ config PCIE_SPACEMIT_K1
> >>> default ARCH_SPACEMIT
> >>> help
> >>> Enables support for the DesignWare based PCIe controller in
> >>> - the SpacemiT K1 SoC operating in host mode. Three controllers
> >>> + the SpacemiT SoC operating in host mode. Three controllers
> >>> are available on the K1 SoC; the first of these shares a PHY
> >>> with a USB 3.0 host controller (one or the other can be used).
> >>>
> >>> diff --git a/drivers/pci/controller/dwc/pcie-spacemit-k1.c b/drivers/pci/controller/dwc/pcie-spacemit-k1.c
> >>> index ec59ccb710ec..61b430f2294a 100644
> >>> --- a/drivers/pci/controller/dwc/pcie-spacemit-k1.c
> >>> +++ b/drivers/pci/controller/dwc/pcie-spacemit-k1.c
> >>> @@ -28,8 +28,18 @@
> >>> #define SMLH_LINK_UP BIT(1)
> >>> #define RDLH_LINK_UP BIT(12)
> >>>
> >>> +#define INTR_STATUS 0x0010
> >>> +
> >>> #define INTR_ENABLE 0x0014
> >>> #define MSI_CTRL_INT BIT(11)
> >>> +#define RDLH_LINK_UP_INT BIT(20)
> >>> +
> >>> +#define K3_PHY_AHB_IRQSTATUS_INTX 0x0008
> >>> +
> >>> +#define K3_ADDR_INTR_STATUS1 0x0018
> >>> +
> >>> +#define K3_CACHE_MSTR_AWCACHE_MODE GENMASK(14, 11)
> >>> +#define K3_CACHE_MSTR_AWCACHE_BEHAVIOR 0xf
> >>>
> >>> /* Some controls require APMU regmap access */
> >>> #define SYSCON_APMU "spacemit,apmu"
> >>> @@ -44,6 +54,9 @@
> >>>
> >>> #define PCIE_CONTROL_LOGIC 0x0004
> >>> #define PCIE_SOFT_RESET BIT(0)
> >>> +#define PCIE_PERSTN_OE BIT(24)
> >>> +#define PCIE_PERSTN_OUT BIT(25)
> >>> +#define PCIE_IGNORE_PERSTN BIT(31)
> >>>
> >>> struct k1_pcie;
> >>>
> >>> @@ -315,6 +328,123 @@ static int k1_pcie_parse_port(struct k1_pcie *k1)
> >>> return ret;
> >>> }
> >>>
> >>> +static int k3_pcie_init(struct dw_pcie_rp *pp)
> >>> +{
> >>> + struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
> >>> + struct k1_pcie *k1 = to_k1_pcie(pci);
> >>> + u32 reset_ctrl = k1->pmu_off + PCIE_CLK_RESET_CONTROL;
> >>> + u32 val;
> >>> + int ret;
> >>> +
> >>> + regmap_clear_bits(k1->pmu, reset_ctrl, LTSSM_EN);
> >>> +
> >>> + k1_pcie_toggle_soft_reset(k1);
> >>> +
> >>> + /* K3: Set IGNORE_PERSTN and drive PERSTN_OE high (assert reset) */
> >>> + regmap_update_bits(k1->pmu, k1->pmu_off + PCIE_CONTROL_LOGIC,
> >>> + PCIE_IGNORE_PERSTN | PCIE_PERSTN_OE | PCIE_PERSTN_OUT,
> >>> + PCIE_IGNORE_PERSTN | PCIE_PERSTN_OE);
> >>> +
> >>> + ret = k1_pcie_enable_resources(k1);
> >>> + if (ret)
> >>> + goto failed_resources;
> >>> +
> >>> + regmap_set_bits(k1->pmu, reset_ctrl, PCIE_AUX_PWR_DET);
> >>> + regmap_clear_bits(k1->pmu, reset_ctrl, APP_HOLD_PHY_RST);
> >>> +
> >>> + ret = phy_bulk_init(k1->phy_count, k1->phys);
> >>> + if (ret)
> >>> + goto failed_phy_init;
> >>
> >> You got me confused with this PHY bulk API for a moment. I think you are trying
> >> to control all the PHYs of the multi-port RC setup at once. But I believe
> >> that's not what we want mostly. Each port is an independent entity with its own
> >> PHY, PERST# etc... So the RC driver controlling all the PHYs at once, doesn't
> >> seem logical.
> >>
> >
> > In fact this thing is different. Accoring to statement from spacemit,
> > for software, it does not need to care about how the phy topology,
> > and which phy/phys is/are attached to the RC. It just needs to enable
> > all the phy and configure the APMU, which is the one that give some
> > control on PERST# and others. The phy itself does nothing on this.
> According to section "14.1.4 PHY Configuration Block Diagram" in the User
> Manual for the Spacemit K3 SoC [0],the x8 Lane PCIe Controller namely 'PCIe
> A' requires multiple PHYs (ranging from PHY0 to PHY5) to be
> initialized/enabled simultaneously for a single Root-Port configuration. So
> the phy_bulk_init() API here seems to be used in that sense. Mani's concern
> is that the PHYs for all PCIe Controller instances are being configured in
> a single invocation to phy_bulk_init() rather than the potentially multiple
> PHY instances of a single PCIe Controller instance. Since k3_pcie_init is
> invoked per Root-Port instance (i.e. per PCIe Controller instance), the
> phy_bulk_init() API should configure 'all' PHY instances _strictly_
> associated with the corresponding PCIe instance. This might already be the
> case.
>
> [0]:
> https://spacemit.com/community/document/info?lang=en&nodepath=hardware/key_stone/k3/k3_docs/k3_usermanual/14_connectivity/pcie.md
>
Thanks for sharing the link to the doc. I didn't know this SoC allows muxing
multiple PHYs for a single RP. Now the bulk API makes sense!
For the next iteration, please include a link to this page.
- Mani