Re: [PATCH v7 6/6] PCI: spacemit-k1: Add Spacemit K3 PCIe host controller support

[Inochi Amaoto <inochiama@gmail.com>]

On Tue, Oct 27, 2026 at 01:30:45PM +0530, Manivannan Sadhasivam wrote:
> 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@gmail.com>
> > >>> ---
> > >>>   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
> 

OK, I will include that, thanks.

Regards,
Inochi