[PATCH 0/6] Introduce SpacemiT K1 PCIe phy and host controller

[PATCH 0/6] Introduce SpacemiT K1 PCIe phy and host controller

[Alex Elder]

This series introduces a PHY driver and a PCIe driver to support PCIe
on the SpacemiT K1 SoC.  The PCIe implementation is derived from a
Synopsys DesignWare PCIe IP.  The PHY driver supports one combination
PCIe/USB PHY as well as two PCIe-only PHYs.  The combo PHY port uses
one PCIe lane, and the other two ports each have two lanes.  All PCIe
ports operate at 5 GT/second.

The PCIe PHYs must be configured using a value that can only be
determined using the combo PHY, operating in PCIe mode.  To allow
that PHY to be used for USB, the calibration step is performed by
the PHY driver automatically at probe time.  Once this step is done,
the PHY can be used for either PCIe or USB.

					-Alex

Alex Elder (6):
  dt-bindings: phy: spacemit: add SpacemiT PCIe/combo PHY
  dt-bindings: phy: spacemit: introduce PCIe PHY
  dt-bindings: phy: spacemit: introduce PCIe root complex
  phy: spacemit: introduce PCIe/combo PHY
  PCI: spacemit: introduce SpacemiT PCIe host driver
  riscv: dts: spacemit: PCIe and PHY-related updates

 .../bindings/pci/spacemit,k1-pcie-rc.yaml     | 141 ++++
 .../bindings/phy/spacemit,k1-combo-phy.yaml   | 110 +++
 .../bindings/phy/spacemit,k1-pcie-phy.yaml    |  49 ++
 .../boot/dts/spacemit/k1-bananapi-f3.dts      |  28 +
 arch/riscv/boot/dts/spacemit/k1-pinctrl.dtsi  |  33 +
 arch/riscv/boot/dts/spacemit/k1.dtsi          | 169 +++++
 drivers/pci/controller/dwc/Kconfig            |  10 +
 drivers/pci/controller/dwc/Makefile           |   1 +
 drivers/pci/controller/dwc/pcie-k1.c          | 355 ++++++++++
 drivers/phy/Kconfig                           |  11 +
 drivers/phy/Makefile                          |   1 +
 drivers/phy/phy-spacemit-k1-pcie.c            | 639 ++++++++++++++++++
 12 files changed, 1547 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pci/spacemit,k1-pcie-rc.yaml
 create mode 100644 Documentation/devicetree/bindings/phy/spacemit,k1-combo-phy.yaml
 create mode 100644 Documentation/devicetree/bindings/phy/spacemit,k1-pcie-phy.yaml
 create mode 100644 drivers/pci/controller/dwc/pcie-k1.c
 create mode 100644 drivers/phy/phy-spacemit-k1-pcie.c


base-commit: 8f5ae30d69d7543eee0d70083daf4de8fe15d585
-- 
2.48.1

[PATCH 1/6] dt-bindings: phy: spacemit: add SpacemiT PCIe/combo PHY

[Alex Elder]

Add the Device Tree binding for the PCIe/USB 3.0 combo PHY found in
the SpacemiT K1 SoC.  This is one of three PCIe PHYs, and is unusual
in that only the combo PHY can perform a calibration step needed to
determine settings used by the other two PCIe PHYs.

Calibration must be done with the combo PHY in PCIe mode, and to allow
this to occur independent of the eventual use for the PHY (PCIe or USB)
some PCIe-related properties must be supplied: clocks; resets; and a
syscon phandle.

Signed-off-by: Alex Elder <elder@riscstar.com>
---
 .../bindings/phy/spacemit,k1-combo-phy.yaml   | 110 ++++++++++++++++++
 1 file changed, 110 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/phy/spacemit,k1-combo-phy.yaml

diff --git a/Documentation/devicetree/bindings/phy/spacemit,k1-combo-phy.yaml b/Documentation/devicetree/bindings/phy/spacemit,k1-combo-phy.yaml
new file mode 100644
index 0000000000000..ed78083a53231
--- /dev/null
+++ b/Documentation/devicetree/bindings/phy/spacemit,k1-combo-phy.yaml
@@ -0,0 +1,110 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/phy/spacemit,k1-combo-phy.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: SpacemiT K1 PCIe/USB3 Combo PHY
+
+maintainers:
+  - Alex Elder <elder@riscstar.com>
+
+description:
+  Of the three PHYs on the SpacemiT K1 SoC capable of being used for
+  PCIe, one is a combo PHY that can also be configured for use by a
+  USB 3 controller.  Using PCIe or USB 3 is a board design decision.
+
+  The combo PHY is also the only PCIe PHY that is able to determine
+  PCIe calibration values to use, and this must be determined before
+  the other two PCIe PHYs can be used.  This calibration must be
+  performed with the combo PHY in PCIe mode, and is this is done
+  when the combo PHY is probed.
+
+  During normal operation, the PCIe or USB port driver is responsible
+  for ensuring all clocks needed by a PHY are enabled, and all resets
+  affecting the PHY are deasserted.  However, for the combo PHY to
+  perform calibration independent of whether it's later used for
+  PCIe or USB, all PCIe mode clocks and resets must be defined.
+
+properties:
+  compatible:
+    const: spacemit,k1-combo-phy
+
+  reg:
+    items:
+      - description: PHY control registers
+
+  clocks:
+    items:
+      - description: DWC PCIe Data Bus Interface (DBI) clock
+      - description: DWC PCIe application AXI-bus Master interface clock
+      - description: DWC PCIe application AXI-bus Slave interface clock.
+
+  clock-names:
+    items:
+      - const: dbi
+      - const: mstr
+      - const: slv
+
+  resets:
+    items:
+      - description: DWC PCIe Data Bus Interface (DBI) reset
+      - description: DWC PCIe application AXI-bus Master interface reset
+      - description: DWC PCIe application AXI-bus Slave interface reset.
+      - description: Global reset; must be deasserted for PHY to function
+
+  reset-names:
+    items:
+      - const: dbi
+      - const: mstr
+      - const: slv
+      - const: global
+
+  spacemit,syscon-pmu:
+    description:
+      PHandle that refers to the APMU system controller, whose
+      regmap is used in setting the mode
+    $ref: /schemas/types.yaml#/definitions/phandle
+
+  "#phy-cells":
+    const: 1
+    description:
+      The argument value (PHY_TYPE_PCIE or PHY_TYPE_USB3) determines
+      whether the PHY operates in PCIe or USB3 mode.
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - clock-names
+  - resets
+  - reset-names
+  - spacemit,syscon-pmu
+  - "#phy-cells"
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/spacemit,k1-syscon.h>
+    combo_phy: phy@c0b10000 {
+        compatible = "spacemit,k1-combo-phy";
+        reg = <0xc0b10000 0x1000>;
+        clocks = <&syscon_apmu CLK_PCIE0_DBI>,
+                 <&syscon_apmu CLK_PCIE0_MASTER>,
+                 <&syscon_apmu CLK_PCIE0_SLAVE>;
+        clock-names = "dbi",
+                      "mstr",
+                      "slv";
+        resets = <&syscon_apmu RESET_PCIE0_DBI>,
+                 <&syscon_apmu RESET_PCIE0_MASTER>,
+                 <&syscon_apmu RESET_PCIE0_SLAVE>,
+                 <&syscon_apmu RESET_PCIE0_GLOBAL>;
+        reset-names = "dbi",
+                      "mstr",
+                      "slv",
+                      "global";
+        spacemit,syscon-pmu = <&syscon_apmu>;
+        #phy-cells = <1>;
+        status = "disabled";
+    };
-- 
2.48.1

[PATCH 2/6] dt-bindings: phy: spacemit: introduce PCIe PHY

[Alex Elder]

Add the Device Tree binding for two PCIe PHYs present on the SpacemiT
K1 SoC.  These PHYs are dependent on a separate combo PHY, which
determines at probe time the calibration values used by the PCIe-only
PHYs.

Signed-off-by: Alex Elder <elder@riscstar.com>
---
 .../bindings/phy/spacemit,k1-pcie-phy.yaml    | 49 +++++++++++++++++++
 1 file changed, 49 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/phy/spacemit,k1-pcie-phy.yaml

diff --git a/Documentation/devicetree/bindings/phy/spacemit,k1-pcie-phy.yaml b/Documentation/devicetree/bindings/phy/spacemit,k1-pcie-phy.yaml
new file mode 100644
index 0000000000000..b0cbd231d9378
--- /dev/null
+++ b/Documentation/devicetree/bindings/phy/spacemit,k1-pcie-phy.yaml
@@ -0,0 +1,49 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/phy/spacemit,k1-pcie-phy.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: SpacemiT K1 PCIe PHY
+
+maintainers:
+  - Alex Elder <elder@riscstar.com>
+
+description:
+  There are two PHYs on the SpacemiT K1 SoC used for PCIe (only).
+  These PHYs must be configured using calibration values that are
+  determined by a third "combo PHY".  The combo PHY determines
+  these calibration values during probe so they can be used for
+  the two PCIe-only PHYs.
+
+  During normal operation, the PCIe port driver is responsible for
+  ensuring all clocks needed by a PHY are enabled, and all resets
+  affecting the PHY are deasserted.
+
+properties:
+  compatible:
+    const: spacemit,k1-pcie-phy
+
+  reg:
+    items:
+      - description: PHY control registers
+
+  "#phy-cells":
+    const: 0
+
+required:
+  - compatible
+  - reg
+  - "#phy-cells"
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/spacemit,k1-syscon.h>
+    pcie1_phy: phy@c0c10000 {
+        compatible = "spacemit,k1-pcie-phy";
+        reg = <0xc0c10000 0x1000>;
+        #phy-cells = <0>;
+        status = "disabled";
+    };
-- 
2.48.1

[PATCH 3/6] dt-bindings: phy: spacemit: introduce PCIe root complex

[Alex Elder]

Add the Device Tree binding for the PCIe root complex found on the
SpacemiT K1 SoC.  This device is derived from the Synopsys Designware
PCIe IP.  It supports up to three PCIe ports operating at PCIe gen 2
link speeds (5 GT/sec).  One of the ports uses a combo PHY, which is
typically used to support a USB 3 port.

Signed-off-by: Alex Elder <elder@riscstar.com>
---
 .../bindings/pci/spacemit,k1-pcie-rc.yaml     | 141 ++++++++++++++++++
 1 file changed, 141 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pci/spacemit,k1-pcie-rc.yaml

diff --git a/Documentation/devicetree/bindings/pci/spacemit,k1-pcie-rc.yaml b/Documentation/devicetree/bindings/pci/spacemit,k1-pcie-rc.yaml
new file mode 100644
index 0000000000000..6bcca2f91a6fd
--- /dev/null
+++ b/Documentation/devicetree/bindings/pci/spacemit,k1-pcie-rc.yaml
@@ -0,0 +1,141 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/pci/spacemit,k1-pcie-rc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: SpacemiT K1 PCI Express Root Complex
+
+maintainers:
+  - Alex Elder <elder@riscstar.com>
+
+description:
+  The SpacemiT K1 SoC PCIe root complex controller is based on the
+  Synopsys DesignWare PCIe IP.
+
+properties:
+  compatible:
+    const: spacemit,k1-pcie-rc.yaml
+
+  reg:
+    items:
+      - description: DesignWare PCIe registers
+      - description: ATU address space
+      - description: PCIe configuration space
+      - description: Link control registers
+
+  reg-names:
+    items:
+      - const: dbi
+      - const: atu
+      - const: config
+      - const: link
+
+  clocks:
+    items:
+      - description: DWC PCIe Data Bus Interface (DBI) clock
+      - description: DWC PCIe application AXI-bus Master interface clock
+      - description: DWC PCIe application AXI-bus Slave interface clock.
+
+  clock-names:
+    items:
+      - const: dbi
+      - const: mstr
+      - const: slv
+
+  resets:
+    items:
+      - description: DWC PCIe Data Bus Interface (DBI) reset
+      - description: DWC PCIe application AXI-bus Master interface reset
+      - description: DWC PCIe application AXI-bus Slave interface reset.
+      - description: Global reset; must be deasserted for PHY to function
+
+  reset-names:
+    items:
+      - const: dbi
+      - const: mstr
+      - const: slv
+      - const: global
+
+  interrupts-extended:
+    maxItems: 1
+
+  spacemit,syscon-pmu:
+    description:
+      PHandle that refers to the APMU system controller, whose
+      regmap is used in managing resets and link state.
+    $ref: /schemas/types.yaml#/definitions/phandle
+
+  device_type:
+    const: pci
+
+  max-link-speed:
+    const: 2
+
+  num-viewport:
+    const: 8
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - clock-names
+  - resets
+  - reset-names
+  - spacemit,syscon-pmu
+  - "#address-cells"
+  - "#size-cells"
+  - device_type
+  - max-link-speed
+  - bus-range
+  - num-viewport
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/spacemit,k1-syscon.h>
+    pcie0: pcie@ca000000 {
+        compatible = "spacemit,k1-pcie-rc";
+        reg = <0x0 0xca000000 0x0 0x00001000>,
+              <0x0 0xca300000 0x0 0x0001ff24>,
+              <0x0 0x8f000000 0x0 0x00002000>,
+              <0x0 0xc0b20000 0x0 0x00001000>;
+        reg-names = "dbi",
+                    "atu",
+                    "config",
+                    "link";
+
+        ranges = <0x01000000 0x8f002000 0x0 0x8f002000 0x0 0x100000>,
+                 <0x02000000 0x80000000 0x0 0x80000000 0x0 0x0f000000>;
+
+        clocks = <&syscon_apmu CLK_PCIE0_DBI>,
+                 <&syscon_apmu CLK_PCIE0_MASTER>,
+                 <&syscon_apmu CLK_PCIE0_SLAVE>;
+        clock-names = "dbi",
+                      "mstr",
+                      "slv";
+
+        resets = <&syscon_apmu RESET_PCIE0_DBI>,
+                 <&syscon_apmu RESET_PCIE0_MASTER>,
+                 <&syscon_apmu RESET_PCIE0_SLAVE>,
+                 <&syscon_apmu RESET_PCIE0_GLOBAL>;
+        reset-names = "dbi",
+                      "mstr",
+                      "slv",
+                      "global";
+
+        interrupts-extended = <&plic 141>;
+
+        spacemit,syscon-pmu = <&syscon_apmu 0x03cc>;
+
+        #address-cells = <3>;
+        #size-cells = <2>;
+
+        device_type = "pci";
+        max-link-speed = <2>;
+        bus-range = <0x00 0xff>;
+        num-viewport = <8>;
+
+        status = "disabled";
+    };
-- 
2.48.1

[PATCH 4/6] phy: spacemit: introduce PCIe/combo PHY

[Alex Elder]

Introduce a driver that supports three PHYs found on the SpacemiT
K1 SoC.  The first PHY is a combo PHY that can be configured for
use for either USB 3 or PCIe.  The other two PHYs support PCIe
only.

All three PHYs must be programmed with an 8 bit receiver termination
value, which must be determined dynamically; only the combo PHY is
able to determine this value.  The combo PHY performs a special
calibration step at probe time to discover this, and that value is
used to program each PHY that operates in PCIe mode.  The combo
PHY must therefore be probed--first--if either of the PCIe-only
PHYs will be used.

During normal operation, the USB or PCIe driver using the PHY must
ensure clocks and resets are set up properly.  However clocks are
enabled and resets are de-asserted temporarily by this driver to
perform the calibration step on the combo PHY.

Tested-by: Junzhong Pan <panjunzhong@linux.spacemit.com>
Signed-off-by: Alex Elder <elder@riscstar.com>
---
 drivers/phy/Kconfig                |  11 +
 drivers/phy/Makefile               |   1 +
 drivers/phy/phy-spacemit-k1-pcie.c | 639 +++++++++++++++++++++++++++++
 3 files changed, 651 insertions(+)
 create mode 100644 drivers/phy/phy-spacemit-k1-pcie.c

diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
index 58c911e1b2d20..0fa343203f289 100644
--- a/drivers/phy/Kconfig
+++ b/drivers/phy/Kconfig
@@ -101,6 +101,17 @@ config PHY_NXP_PTN3222
 	  schemes. It supports all three USB 2.0 data rates: Low Speed, Full
 	  Speed and High Speed.
 
+config PHY_SPACEMIT_K1_PCIE
+	tristate "PCIe and combo PHY driver for the SpacemiT K1 SoC"
+	depends on ARCH_SPACEMIT || COMPILE_TEST
+	depends on HAS_IOMEM
+	depends on OF
+	select GENERIC_PHY
+	default ARCH_SPACEMIT
+	help
+	  Enable support for the PCIe and USB 3 combo PHY and two
+	  PCIe-only PHYs used in the SpacemiT K1 SoC.
+
 source "drivers/phy/allwinner/Kconfig"
 source "drivers/phy/amlogic/Kconfig"
 source "drivers/phy/broadcom/Kconfig"
diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
index c670a8dac4680..20f0078e543c7 100644
--- a/drivers/phy/Makefile
+++ b/drivers/phy/Makefile
@@ -13,6 +13,7 @@ obj-$(CONFIG_PHY_SNPS_EUSB2)		+= phy-snps-eusb2.o
 obj-$(CONFIG_USB_LGM_PHY)		+= phy-lgm-usb.o
 obj-$(CONFIG_PHY_AIROHA_PCIE)		+= phy-airoha-pcie.o
 obj-$(CONFIG_PHY_NXP_PTN3222)		+= phy-nxp-ptn3222.o
+obj-$(CONFIG_PHY_SPACEMIT_K1_PCIE)	+= phy-spacemit-k1-pcie.o
 obj-y					+= allwinner/	\
 					   amlogic/	\
 					   broadcom/	\
diff --git a/drivers/phy/phy-spacemit-k1-pcie.c b/drivers/phy/phy-spacemit-k1-pcie.c
new file mode 100644
index 0000000000000..32dce53170fbb
--- /dev/null
+++ b/drivers/phy/phy-spacemit-k1-pcie.c
@@ -0,0 +1,639 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * SpacemiT K1 PCIe and PCIe/USB 3 combo PHY driver
+ *
+ * Copyright (C) 2025 by RISCstar Solutions Corporation.  All rights reserved.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/iopoll.h>
+#include <linux/kernel.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/reset.h>
+
+#include <dt-bindings/phy/phy.h>
+
+/*
+ * Three PCIe ports are supported in the SpacemiT K1 SoC, and this driver
+ * supports their PHYs.
+ *
+ * The PHY for PCIe port A is different from the PHYs for ports B and C:
+ * - It has one lane, while ports B and C have two
+ * - It is a combo PHY can be used for PCIe or USB 3
+ * - It can automatically calibrate PCIe TX and RX termination settings
+ *
+ * The PHY functionality for PCIe ports B and C is identical:
+ * - They have two PCIe lanes (but can be restricted to 1 via Device Tree)
+ * - They are used for PCIe only
+ * - They are configured using TX and RX values computed for port A
+ *
+ * A given board is designed to use the combo PHY for either PCIe or USB 3.
+ * Whether the combo PHY is configured for PCIe or USB 3 is specified in
+ * Device Tree using a phandle plus an argument.  The argument indicates
+ * the type (either PHY_TYPE_PCIE or PHY_TYPE_USB3).
+ *
+ * Each PHY depends on clocks and resets provided by the controller
+ * hardware (PCIe or USB) it is associated with.  The controller drivers
+ * are required to enable any clocks and de-assert any resets that affect
+ * PHY operation.
+ *
+ * PCIe PHYs must be programmed with RX and TX calibration values.  The
+ * combo PHY is the only one that can determine these values.  They are
+ * determined by temporarily enabling the combo PHY in PCIe mode at probe
+ * time (if necessary).  This calibration only needs to be done once, and
+ * when it has completed the TX and RX values are saved.
+ *
+ * To allow the combo PHY to be enabled for calibration, the resets and
+ * clocks it uses in PCIe mode must be supplied.
+ */
+
+struct k1_pcie_phy {
+	struct device *dev;		/* PHY provider device */
+	struct phy *phy;
+	void __iomem *regs;
+	u32 pcie_lanes;			/* Max unless limited by DT */
+	/* The remaining fields are only used for the combo PHY */
+	u32 type;			/* PHY_TYPE_PCIE or PHY_TYPE_USB3 */
+	struct regmap *pmu;
+};
+
+#define CALIBRATION_TIMEOUT		500000	/* microseconds */
+#define PLL_TIMEOUT			500000	/* microseconds */
+#define POLL_DELAY			500	/* microseconds */
+
+/* Selecting the combo PHY operating mode requires PMU regmap access */
+#define SYSCON_PMU			"spacemit,syscon-pmu"
+
+/* PMU space, for selecting between PCIe and USB3 mode on the combo PHY */
+
+#define PMUA_USB_PHY_CTRL0			0x0110
+#define COMBO_PHY_SEL			BIT(3)	/* 0: PCIe; 1: USB3 */
+
+#define PCIE_CLK_RES_CTRL			0x03cc
+#define PCIE_APP_HOLD_PHY_RST		BIT(30)
+
+/* PHY register space */
+
+/* Offset between lane 0 and lane 1 registers when there are two */
+#define PHY_LANE_OFFSET				0x0400
+
+#define PCIE_PU_ADDR_CLK_CFG			0x0008
+#define PLL_READY			BIT(0)		/* read-only */
+#define CFG_RXCLK_EN			BIT(3)
+#define CFG_TXCLK_EN			BIT(4)
+#define CFG_PCLK_EN			BIT(5)
+#define CFG_PIPE_PCLK_EN		BIT(6)
+#define CFG_INTERNAL_TIMER_ADJ		GENMASK(10, 7)
+#define TIMER_ADJ_USB		0x2
+#define TIMER_ADJ_PCIE		0x6
+#define CFG_SW_PHY_INIT_DONE		BIT(11)	/* We set after PLL config */
+
+#define PCIE_RC_DONE_STATUS			0x0018
+#define CFG_FORCE_RCV_RETRY		BIT(10)
+
+#define PCIE_RC_CAL_REG2			0x0020
+#define RC_CAL_TOGGLE			BIT(22)
+#define CLKSEL				GENMASK(31, 29)
+#define CLKSEL_24M		0x3
+
+#define PCIE_PU_PLL_1				0x0048
+#define REF_100_WSSC			BIT(12)	/* 1: input is 100MHz, SSC */
+#define FREF_SEL			GENMASK(15, 13)
+#define FREF_24M		0x1
+#define SSC_DEP_SEL			GENMASK(19, 16)
+#define SSC_DEP_NONE		0x0
+#define SSC_DEP_5000PPM		0xa
+#define SSC_MODE			GENMASK(21, 20)
+#define SSC_MODE_DOWN_SPREAD	0x3
+#define SSC_OFFSET			GENMASK(23, 22)
+#define SSC_OFFSET_0_PPM	0x0
+
+#define PCIE_PU_PLL_2				0x004c
+#define GEN_REF100			BIT(4)	/* 1: generate 100MHz clk */
+
+#define PCIE_RX_REG1				0x0050
+#define EN_RTERM			BIT(3)
+#define AFE_RTERM_REG			GENMASK(11, 8)
+
+#define PCIE_RX_REG2				0x0054
+#define RX_RTERM_SEL			BIT(5)	/* 0: use AFE_RTERM_REG value */
+
+#define PCIE_LTSSM_DIS_ENTRY			0x005c
+#define CFG_REFCLK_MODE			GENMASK(9, 8)
+#define RFCLK_MODE_DRIVER	0x1
+#define OVRD_REFCLK_MODE		BIT(10)	/* 1: use CFG_RFCLK_MODE */
+
+#define PCIE_TX_REG1				0x0064
+#define TX_RTERM_REG			GENMASK(15, 12)
+#define TX_RTERM_SEL			BIT(25)	/* 1: use TX_RTERM_REG */
+
+#define USB3_TEST_CTRL				0x0068
+
+#define PCIE_RCAL_RESULT			0x0084	/* Port A PHY only */
+#define RTERM_VALUE_RX			GENMASK(3, 0)
+#define RTERM_VALUE_TX			GENMASK(7, 4)
+#define R_TUNE_DONE			BIT(10)
+
+static u32 k1_phy_rterm = ~0;     /* Invalid initial value */
+
+/* Save the RX and TX receiver termination values */
+static void k1_phy_rterm_set(u32 val)
+{
+	k1_phy_rterm = val & (RTERM_VALUE_RX | RTERM_VALUE_TX);
+}
+
+static bool k1_phy_rterm_valid(void)
+{
+	/* Valid if no bits outside those we care about are set */
+	return !(k1_phy_rterm & ~(RTERM_VALUE_RX | RTERM_VALUE_TX));
+}
+
+static u32 k1_phy_rterm_rx(void)
+{
+	return FIELD_GET(RTERM_VALUE_RX, k1_phy_rterm);
+}
+
+static u32 k1_phy_rterm_tx(void)
+{
+	return FIELD_GET(RTERM_VALUE_TX, k1_phy_rterm);
+}
+
+/* Only the combo PHY has a PMU pointer defined */
+static bool k1_phy_port_a(struct k1_pcie_phy *k1_phy)
+{
+	return !!k1_phy->pmu;
+}
+
+/*
+ * Select PCIe or USB 3 mode for the combo PHY.  Return 1 if the bit
+ * was changed, 0 if it was not, or a negative error value otherwise.
+ */
+static int k1_combo_phy_sel(struct k1_pcie_phy *k1_phy, bool usb3)
+{
+	int ret;
+
+	ret = regmap_test_bits(k1_phy->pmu, PMUA_USB_PHY_CTRL0, COMBO_PHY_SEL);
+	if (ret < 0)
+		return ret;
+
+	/* If it's already in the desired state, we're done */
+	if (!!ret == usb3)
+		return 0;
+
+	/* Change the bit */
+	ret = regmap_assign_bits(k1_phy->pmu, PMUA_USB_PHY_CTRL0,
+				 COMBO_PHY_SEL, usb3);
+
+	return ret < 0 ? ret : 1;
+}
+
+static void k1_pcie_phy_init_pll(struct k1_pcie_phy *k1_phy,
+				 void __iomem *regs, bool pcie)
+{
+	void __iomem *virt;
+	u32 timer_adj;
+	u32 ssc_dep;
+	u32 val;
+
+	if (pcie) {
+		timer_adj = TIMER_ADJ_PCIE;
+		ssc_dep = SSC_DEP_NONE;
+	} else {
+		timer_adj = TIMER_ADJ_USB;
+		ssc_dep = SSC_DEP_5000PPM;
+	}
+
+	/*
+	 * Disable 100 MHz input reference with spread-spectrum
+	 * clocking and select the 24 MHz clock input frequency
+	 */
+	virt = k1_phy->regs + PCIE_PU_PLL_1;
+	val = readl(virt);
+	val &= ~REF_100_WSSC;
+
+	val &= ~FREF_SEL;
+	val |= FIELD_PREP(FREF_SEL, FREF_24M);
+
+	val &= ~SSC_DEP_SEL;
+	val |= FIELD_PREP(SSC_DEP_SEL, ssc_dep);
+
+	val &= ~SSC_MODE;
+	val |= FIELD_PREP(SSC_MODE, SSC_MODE_DOWN_SPREAD);
+
+	val &= ~SSC_OFFSET;
+	val |= FIELD_PREP(SSC_OFFSET, SSC_OFFSET_0_PPM);
+	writel(val, virt);
+
+	if (pcie) {
+		virt = regs + PCIE_PU_PLL_2;
+		val = readl(virt);
+		val |= GEN_REF100;	/* Enable 100 MHz PLL output clock */
+		writel(val, virt);
+	}
+
+	/* Enable clocks and mark PLL initialization done */
+	virt = regs + PCIE_PU_ADDR_CLK_CFG;
+	val = readl(virt);
+	val |= CFG_RXCLK_EN;
+	val |= CFG_TXCLK_EN;
+	val |= CFG_PCLK_EN;
+	val |= CFG_PIPE_PCLK_EN;
+
+	val &= ~CFG_INTERNAL_TIMER_ADJ;
+	val |= FIELD_PREP(CFG_INTERNAL_TIMER_ADJ, timer_adj);
+
+	val |= CFG_SW_PHY_INIT_DONE;
+	writel(val, virt);
+}
+
+static int k1_pcie_pll_lock(struct k1_pcie_phy *k1_phy, bool pcie)
+{
+	u32 val = pcie ? CFG_FORCE_RCV_RETRY : 0;
+	void __iomem *virt;
+
+	writel(val, k1_phy->regs + PCIE_RC_DONE_STATUS);
+
+	/*
+	 * Wait for indication the PHY PLL is locked.  Lanes for ports
+	 * B and C share a PLL, so it's enough to sample just lane 0.
+	 */
+	virt = k1_phy->regs + PCIE_PU_ADDR_CLK_CFG;	/* Lane 0 */
+
+	return readl_poll_timeout(virt, val, val & PLL_READY,
+				  POLL_DELAY, PLL_TIMEOUT);
+}
+
+static int k1_pcie_phy_init_pcie(struct k1_pcie_phy *k1_phy)
+{
+	u32 rx_rterm = k1_phy_rterm_rx();
+	u32 tx_rterm = k1_phy_rterm_tx();
+	void __iomem *virt;
+	void __iomem *regs;
+	u32 val;
+	int ret;
+	int i;
+
+	/* For the combo PHY, set PHY to PCIe mode */
+	if (k1_phy_port_a(k1_phy)) {
+		ret = k1_combo_phy_sel(k1_phy, false);
+		if (ret < 0)
+			return ret;
+	}
+
+	regs = k1_phy->regs;
+	for (i = 0; i < k1_phy->pcie_lanes; i++) {
+		virt = regs + PCIE_RX_REG1;
+		val = readl(virt);
+
+		/* Set RX analog front-end receiver termination value */
+		val &= ~AFE_RTERM_REG;
+		val |= FIELD_PREP(AFE_RTERM_REG, rx_rterm);
+
+		/* And enable refclock receiver termination */
+		val |= EN_RTERM;
+		writel(val, virt);
+
+		virt = regs + PCIE_RX_REG2;
+		val = readl(virt);
+		/* Use PCIE_RX_REG1 AFE_RTERM_REG value */
+		val &= ~RX_RTERM_SEL;
+		writel(val, virt);
+
+		virt = regs + PCIE_TX_REG1;
+		val = readl(virt);
+
+		/* Set TX driver termination value */
+		val &= ~TX_RTERM_REG;
+		val |= FIELD_PREP(TX_RTERM_REG, tx_rterm);
+
+		/* Use PCIE_TX_REG1 TX_RTERM_REG value */
+		val |= TX_RTERM_SEL;
+		writel(val, virt);
+
+		virt = regs + PCIE_RC_CAL_REG2;
+		val = readl(virt);
+
+		/* Set the input clock to 24 MHz, and clear RC_CAL_TOGGLE */
+		val &= CLKSEL;
+		val |= FIELD_PREP(CLKSEL, CLKSEL_24M);
+
+		val &= ~RC_CAL_TOGGLE;
+		writel(val, virt);
+		/* Trigger recalibration by setting RC_CAL_TOGGLE again */
+		val |= RC_CAL_TOGGLE;
+		writel(val, virt);
+
+		virt = regs + PCIE_LTSSM_DIS_ENTRY;
+		val = readl(virt);
+		/* Override the reference clock; set to refclk driver mode */
+		val |= OVRD_REFCLK_MODE;
+
+		val &= ~CFG_REFCLK_MODE;
+		val |= FIELD_PREP(CFG_REFCLK_MODE, RFCLK_MODE_DRIVER);
+
+		writel(val, virt);
+
+		k1_pcie_phy_init_pll(k1_phy, regs, true);
+
+		regs += PHY_LANE_OFFSET;	/* Next lane */
+	}
+
+	return k1_pcie_pll_lock(k1_phy, true);
+}
+
+/* Only called for combo PHY */
+static int k1_pcie_phy_init_usb3_host(struct k1_pcie_phy *k1_phy)
+{
+	int ret;
+
+	ret = k1_combo_phy_sel(k1_phy, true);
+	if (ret < 0)
+		return ret;
+
+	/* We're not doing any testing */
+	writel(0, k1_phy->regs + USB3_TEST_CTRL);
+
+	k1_pcie_phy_init_pll(k1_phy, k1_phy->regs, false);
+
+	return k1_pcie_pll_lock(k1_phy, false);
+}
+
+static int k1_pcie_phy_init(struct phy *phy)
+{
+	struct k1_pcie_phy *k1_phy = phy_get_drvdata(phy);
+
+	if (k1_phy_port_a(k1_phy) && k1_phy->type == PHY_TYPE_USB3)
+		return k1_pcie_phy_init_usb3_host(k1_phy);
+
+	return k1_pcie_phy_init_pcie(k1_phy);
+}
+
+static const struct phy_ops k1_pcie_phy_ops = {
+	.init		= k1_pcie_phy_init,
+	.owner		= THIS_MODULE,
+};
+
+/*
+ * Get values needed for calibrating PHYs operating in PCIe mode.  Only
+ * the combo PHY is able to do this, and its calibration values are used
+ * for configuring all PCIe PHYs.
+ *
+ * We always need to de-assert the (PCIe) global reset on the combo PHY,
+ * because the USB driver depends on it.  If used for PCIe, the driver
+ * will (also) de-assert this, but by leaving it de-asserted for the
+ * combo PHY, the USB driver doesn't have to do this.
+ * of this first.
+ *
+ * In addition, we guarantee the APP_HOLD_PHY_RESET bit is clear for the
+ * combo PHY, so the USB driver doesn't have to manage that either.  The
+ * PCIe driver is free to change this bit for normal operation.
+ *
+ * Calibration only needs to be done once.  It's possible calibration has
+ * already completed (e.g., it might have happened in the boot loader, or
+ * -EPROBE_DEFER might result in this function being called again).  So we
+ * check that early too, to avoid doing it more than once.
+ *
+ * Otherwise we temporarily power up the PHY, wait for the hardware to
+ * indicate calibration is done, grab the value, then shut the PHY down
+ * again.
+ */
+static int k1_pcie_combo_phy_calibrate(struct k1_pcie_phy *k1_phy)
+{
+	struct reset_control_bulk_data data[] = {
+		{ .id = "dbi", },
+		{ .id = "mstr", },
+		{ .id = "slv", },
+	};
+	size_t data_size = ARRAY_SIZE(data);
+	struct reset_control *global_reset;
+	struct device *dev = k1_phy->dev;
+	struct clk_bulk_data *clocks;
+	void __iomem *virt;
+	bool mode_changed;
+	u32 clock_count;
+	int ret = 0;
+	int val;
+
+	/* We always de-assert the global reset and leave it that way */
+	global_reset = devm_reset_control_get_shared_deasserted(dev, "global");
+	if (IS_ERR(global_reset))
+		return PTR_ERR(global_reset);
+
+	/*
+	 * We also guarantee the APP_HOLD_PHY_RESET bit is clear.  If an
+	 * error occurs we can't go on, but otherwise we can leave this
+	 * bit clear even if an error happens below.
+	 */
+	ret = regmap_assign_bits(k1_phy->pmu, PCIE_CLK_RES_CTRL,
+				 PCIE_APP_HOLD_PHY_RST, false);
+	if (ret < 0)
+		return ret;
+
+	/* If the receiver termination value is valid, nothing more to do */
+	if (k1_phy_rterm_valid())
+		return 0;
+
+	/* If the calibration already completed (e.g. by U-Boot), we're done */
+	virt = k1_phy->regs + PCIE_RCAL_RESULT;
+	val = readl(virt);
+	if (val & R_TUNE_DONE)
+		goto done;
+
+	/* Make sure the PHY is configured for PCIe */
+	ret = k1_combo_phy_sel(k1_phy, false);
+	if (ret < 0)
+		return ret;
+	mode_changed = ret > 0;
+
+	/* Get and enable all clocks */
+	ret = clk_bulk_get_all(dev, &clocks);
+	if (ret < 0)
+		return ret;
+	if (!ret)
+		return -ENOENT;
+	clock_count = ret;
+
+	ret = clk_bulk_prepare_enable(clock_count, clocks);
+	if (ret)
+		goto out_put_clocks;
+
+	/* Get the (not "global") PCIe application resets */
+	ret = reset_control_bulk_get_shared(dev, data_size, data);
+	if (ret)
+		goto out_disable_clocks;
+
+	/* De-assert the PCIe application resets */
+	ret = reset_control_bulk_deassert(data_size, data);
+	if (ret)
+		goto out_put_resets;
+
+	/*
+	 * This is the core activity here.  Wait for the hardware to
+	 * signal that it has completed calibration/tuning.  Once it
+	 * has, the register value will contain the values we'll
+	 * use to configure PCIe PHYs.
+	 */
+	ret = readl_poll_timeout(virt, val, val & R_TUNE_DONE,
+				 POLL_DELAY, CALIBRATION_TIMEOUT);
+
+	/* Clean up.  We're done with the resets and clocks */
+	reset_control_bulk_assert(data_size, data);
+out_put_resets:
+	reset_control_bulk_put(data_size, data);
+out_disable_clocks:
+	clk_bulk_disable_unprepare(clock_count, clocks);
+out_put_clocks:
+	clk_bulk_put_all(clock_count, clocks);
+
+	/* If we changed the mode, restore the original state */
+	if (mode_changed)
+		(void)k1_combo_phy_sel(k1_phy, true);
+done:
+	/* If we got the value without timing out, set k1_phy_rterm */
+	if (!ret)
+		k1_phy_rterm_set(val);
+
+	return ret;
+}
+
+static struct phy *
+k1_pcie_combo_phy_xlate(struct device *dev, const struct of_phandle_args *args)
+{
+	struct k1_pcie_phy *k1_phy = dev_get_drvdata(dev);
+	u32 type;
+
+	/* The argument specifying the PHY mode is required */
+	if (args->args_count != 1)
+		return ERR_PTR(-EINVAL);
+
+	/* We only support PCIe and USB3 mode */
+	type = args->args[0];
+	if (type != PHY_TYPE_PCIE && type != PHY_TYPE_USB3)
+		return ERR_PTR(-EINVAL);
+
+	/* This PHY can only be used once */
+	if (k1_phy->type != PHY_NONE)
+		return ERR_PTR(-EBUSY);
+
+	k1_phy->type = type;
+
+	return k1_phy->phy;
+}
+
+/* Use the maximum number of PCIe lanes unless limited by Device Tree */
+static u32 k1_pcie_num_lanes(struct k1_pcie_phy *k1_phy, bool port_a)
+{
+	struct device *dev = k1_phy->dev;
+	u32 count = 0;
+	u32 max;
+	int ret;
+
+	ret = of_property_read_u32(dev_of_node(dev), "num-lanes", &count);
+	if (count == 1)
+		return 1;
+
+	if (count == 2 && !port_a)
+		return 2;
+
+	max = port_a ? 1 : 2;
+	if (ret != -EINVAL)
+		dev_warn(dev, "bad lane count %u for port; using %u\n",
+			 count, max);
+
+	return max;
+}
+
+static int k1_pcie_combo_phy_probe(struct k1_pcie_phy *k1_phy)
+{
+	struct device *dev = k1_phy->dev;
+	struct regmap *regmap;
+	int ret;
+
+	/* Setting the PHY mode requires access to the PMU regmap */
+	regmap = syscon_regmap_lookup_by_phandle(dev_of_node(dev), SYSCON_PMU);
+	if (IS_ERR(regmap))
+		return dev_err_probe(dev, PTR_ERR(regmap),
+				     "error getting PMU\n");
+	k1_phy->pmu = regmap;
+
+	ret = k1_pcie_combo_phy_calibrate(k1_phy);
+	if (ret)
+		return dev_err_probe(dev, ret, "calibration failed\n");
+
+	/* Needed by k1_pcie_combo_phy_xlate(), which also sets k1_phy->type */
+	dev_set_drvdata(dev, k1_phy);
+
+	return 0;
+}
+
+static int k1_pcie_phy_probe(struct platform_device *pdev)
+{
+	struct phy *(*xlate)(struct device *, const struct of_phandle_args *);
+	struct device *dev = &pdev->dev;
+	struct phy_provider *provider;
+	struct k1_pcie_phy *k1_phy;
+	bool probing_port_a;
+	int ret;
+
+	xlate = of_device_get_match_data(dev);
+	probing_port_a = xlate == k1_pcie_combo_phy_xlate;
+
+	/* Only the combo PHY can calibrate, so it must probe first */
+	if (!k1_phy_rterm_valid() && !probing_port_a)
+		return -EPROBE_DEFER;
+
+	k1_phy = devm_kzalloc(dev, sizeof(*k1_phy), GFP_KERNEL);
+	if (!k1_phy)
+		return -ENOMEM;
+	k1_phy->dev = dev;
+
+	k1_phy->regs = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(k1_phy->regs))
+		return dev_err_probe(dev, PTR_ERR(k1_phy->regs),
+				     "error mapping registers\n");
+
+	k1_phy->pcie_lanes = k1_pcie_num_lanes(k1_phy, probing_port_a);
+
+	if (probing_port_a) {
+		ret = k1_pcie_combo_phy_probe(k1_phy);
+		if (ret)
+			return dev_err_probe(dev, ret,
+					     "error probing combo phy\n");
+	}
+
+	k1_phy->phy = devm_phy_create(dev, NULL, &k1_pcie_phy_ops);
+	if (IS_ERR(k1_phy->phy))
+		return dev_err_probe(dev, PTR_ERR(k1_phy->phy),
+				     "error creating phy\n");
+	phy_set_drvdata(k1_phy->phy, k1_phy);
+
+	provider = devm_of_phy_provider_register(dev, xlate);
+	if (IS_ERR(provider))
+		return dev_err_probe(dev, PTR_ERR(provider),
+				     "error registering provider\n");
+	return 0;
+}
+
+static const struct of_device_id k1_pcie_phy_of_match[] = {
+	{ .compatible = "spacemit,k1-combo-phy", k1_pcie_combo_phy_xlate, },
+	{ .compatible = "spacemit,k1-pcie-phy", of_phy_simple_xlate, },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, k1_pcie_phy_of_match);
+
+static struct platform_driver k1_pcie_phy_driver = {
+	.probe	= k1_pcie_phy_probe,
+	.driver = {
+		.of_match_table	= k1_pcie_phy_of_match,
+		.name = "k1-pcie-phy",
+	}
+};
+module_platform_driver(k1_pcie_phy_driver);
+
+MODULE_DESCRIPTION("SpacemiT K1 PCIe 3.0 and USB 3 PHY driver");
+MODULE_LICENSE("GPL");
-- 
2.48.1

[PATCH 5/6] PCI: spacemit: introduce SpacemiT PCIe host driver

[Alex Elder]

Introduce a driver for the PCIe root complex found in the SpacemiT
K1 SoC.  The hardware is derived from the Synopsys DesignWare PCIe IP.
The driver supports three PCIe ports that operate at PCIe v2 transfer
rates (5 GT/sec).  The first port uses a combo PHY, which may be
configured for use for USB 3 instead.

Signed-off-by: Alex Elder <elder@riscstar.com>
---
 drivers/pci/controller/dwc/Kconfig   |  10 +
 drivers/pci/controller/dwc/Makefile  |   1 +
 drivers/pci/controller/dwc/pcie-k1.c | 355 +++++++++++++++++++++++++++
 3 files changed, 366 insertions(+)
 create mode 100644 drivers/pci/controller/dwc/pcie-k1.c

diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig
index ff6b6d9e18ecf..ca5782c041ce8 100644
--- a/drivers/pci/controller/dwc/Kconfig
+++ b/drivers/pci/controller/dwc/Kconfig
@@ -492,4 +492,14 @@ config PCIE_VISCONTI_HOST
 	  Say Y here if you want PCIe controller support on Toshiba Visconti SoC.
 	  This driver supports TMPV7708 SoC.
 
+config PCIE_K1
+	bool "SpacemiT K1 host mode PCIe controller"
+	depends on ARCH_SPACEMIT || COMPILE_TEST
+	depends on PCI && OF && HAS_IOMEM
+	select PCIE_DW_HOST
+	default ARCH_SPACEMIT
+	help
+	  Enables support for the PCIe controller in the K1 SoC operating
+	  in host mode.
+
 endmenu
diff --git a/drivers/pci/controller/dwc/Makefile b/drivers/pci/controller/dwc/Makefile
index 6919d27798d13..62d9d4e7dd4d3 100644
--- a/drivers/pci/controller/dwc/Makefile
+++ b/drivers/pci/controller/dwc/Makefile
@@ -31,6 +31,7 @@ obj-$(CONFIG_PCIE_UNIPHIER) += pcie-uniphier.o
 obj-$(CONFIG_PCIE_UNIPHIER_EP) += pcie-uniphier-ep.o
 obj-$(CONFIG_PCIE_VISCONTI_HOST) += pcie-visconti.o
 obj-$(CONFIG_PCIE_RCAR_GEN4) += pcie-rcar-gen4.o
+obj-$(CONFIG_PCIE_K1) += pcie-k1.o
 
 # The following drivers are for devices that use the generic ACPI
 # pci_root.c driver but don't support standard ECAM config access.
diff --git a/drivers/pci/controller/dwc/pcie-k1.c b/drivers/pci/controller/dwc/pcie-k1.c
new file mode 100644
index 0000000000000..e9b1df3428d16
--- /dev/null
+++ b/drivers/pci/controller/dwc/pcie-k1.c
@@ -0,0 +1,355 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * SpacemiT K1 PCIe host driver
+ *
+ * Copyright (C) 2025 by RISCstar Solutions Corporation.  All rights reserved.
+ * Copyright (c) 2023, spacemit Corporation.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/gfp.h>
+#include <linux/irq.h>
+#include <linux/mfd/syscon.h>
+#include <linux/mod_devicetable.h>
+#include <linux/of.h>
+#include <linux/pci.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/reset.h>
+#include <linux/types.h>
+
+#include "pcie-designware.h"
+
+#define K1_PCIE_VENDOR_ID	0x201f
+#define K1_PCIE_DEVICE_ID	0x0001
+
+/* Offsets and field definitions of link management registers */
+
+#define K1_PHY_AHB_IRQ_EN			0x0000
+#define PCIE_INTERRUPT_EN		BIT(0)
+
+#define K1_PHY_AHB_LINK_STS			0x0004
+#define SMLH_LINK_UP			BIT(1)
+#define RDLH_LINK_UP			BIT(12)
+
+#define INTR_ENABLE				0x0014
+#define MSI_CTRL_INT			BIT(11)
+
+/* Offsets and field definitions for PMU registers */
+
+#define PCIE_CLK_RESET_CONTROL			0x0000
+#define LTSSM_EN			BIT(6)
+#define PCIE_AUX_PWR_DET		BIT(9)
+#define PCIE_RC_PERST			BIT(12)	/* 0: PERST# high; 1: low */
+#define APP_HOLD_PHY_RST		BIT(30)
+#define DEVICE_TYPE_RC			BIT(31)	/* 0: endpoint; 1: RC */
+
+#define PCIE_CONTROL_LOGIC			0x0004
+#define PCIE_SOFT_RESET			BIT(0)
+
+struct k1_pcie {
+	struct dw_pcie pci;
+	void __iomem *link;
+	struct regmap *pmu;
+	u32 pmu_off;
+	struct phy *phy;
+	struct reset_control *global_reset;
+};
+
+#define to_k1_pcie(dw_pcie)	dev_get_drvdata((dw_pcie)->dev)
+
+static int k1_pcie_toggle_soft_reset(struct k1_pcie *k1)
+{
+	u32 offset = k1->pmu_off + PCIE_CONTROL_LOGIC;
+	const u32 mask = PCIE_SOFT_RESET;
+	int ret;
+
+	ret = regmap_set_bits(k1->pmu, offset, mask);
+	if (ret)
+		return ret;
+
+	mdelay(2);
+
+	return regmap_clear_bits(k1->pmu, offset, mask);
+}
+
+/* Enable app clocks, deassert app resets */
+static int k1_pcie_app_enable(struct k1_pcie *k1)
+{
+	struct dw_pcie *pci = &k1->pci;
+	u32 clock_count;
+	u32 reset_count;
+	int ret;
+
+	clock_count = ARRAY_SIZE(pci->app_clks);
+	ret = clk_bulk_prepare_enable(clock_count, pci->app_clks);
+	if (ret)
+		return ret;
+
+	reset_count = ARRAY_SIZE(pci->app_rsts);
+	ret = reset_control_bulk_deassert(reset_count, pci->app_rsts);
+	if (ret)
+		goto err_disable_clks;
+
+	ret = reset_control_deassert(k1->global_reset);
+	if (ret)
+		goto err_assert_resets;
+
+	return 0;
+
+err_assert_resets:
+	(void)reset_control_bulk_assert(reset_count, pci->app_rsts);
+err_disable_clks:
+	clk_bulk_disable_unprepare(clock_count, pci->app_clks);
+
+	return ret;
+}
+
+/* Disable app clocks, assert app resets */
+static void k1_pcie_app_disable(struct k1_pcie *k1)
+{
+	struct dw_pcie *pci = &k1->pci;
+	u32 count;
+	int ret;
+
+	(void)reset_control_assert(k1->global_reset);
+
+	count = ARRAY_SIZE(pci->app_rsts);
+	ret = reset_control_bulk_assert(count, pci->app_rsts);
+	if (ret)
+		dev_err(pci->dev, "app reset assert failed (%d)\n", ret);
+
+	count = ARRAY_SIZE(pci->app_clks);
+	clk_bulk_disable_unprepare(count, pci->app_clks);
+}
+
+static int k1_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 offset;
+	u32 mask;
+	int ret;
+
+	ret = k1_pcie_toggle_soft_reset(k1);
+	if (ret)
+		goto err_app_disable;
+
+	ret = k1_pcie_app_enable(k1);
+	if (ret)
+		return ret;
+
+	ret = phy_init(k1->phy);
+	if (ret)
+		goto err_app_disable;
+
+	/* Set the PCI vendor and device ID */
+	dw_pcie_dbi_ro_wr_en(pci);
+	dw_pcie_writew_dbi(pci, PCI_VENDOR_ID, K1_PCIE_VENDOR_ID);
+	dw_pcie_writew_dbi(pci, PCI_DEVICE_ID, K1_PCIE_DEVICE_ID);
+	dw_pcie_dbi_ro_wr_dis(pci);
+
+	/*
+	 * Put the port in root complex mode, record that Vaux is present.
+	 * Assert fundamental reset (drive PERST# low).
+	 */
+	offset = k1->pmu_off + PCIE_CLK_RESET_CONTROL;
+	mask = DEVICE_TYPE_RC | PCIE_AUX_PWR_DET;
+	mask |= PCIE_RC_PERST;
+	ret = regmap_set_bits(k1->pmu, offset, mask);
+	if (ret)
+		goto err_phy_exit;
+
+	/* Wait the PCIe-mandated 100 msec before deasserting PERST# */
+	mdelay(100);
+
+	ret = regmap_clear_bits(k1->pmu, offset, PCIE_RC_PERST);
+	if (!ret)
+		return 0;	/* Success! */
+
+err_phy_exit:
+	(void)phy_exit(k1->phy);
+err_app_disable:
+	k1_pcie_app_disable(k1);
+
+	return ret;
+}
+
+/* Silently ignore any errors */
+static void k1_pcie_deinit(struct dw_pcie_rp *pp)
+{
+	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+	struct k1_pcie *k1 = to_k1_pcie(pci);
+
+	/* Re-assert fundamental reset (drive PERST# low) */
+	(void)regmap_set_bits(k1->pmu, k1->pmu_off + PCIE_CLK_RESET_CONTROL,
+			      PCIE_RC_PERST);
+
+	(void)phy_exit(k1->phy);
+
+	k1_pcie_app_disable(k1);
+}
+
+static const struct dw_pcie_host_ops k1_pcie_host_ops = {
+	.init		= k1_pcie_init,
+	.deinit		= k1_pcie_deinit,
+};
+
+static void k1_pcie_enable_interrupts(struct k1_pcie *k1)
+{
+	void __iomem *virt;
+	u32 val;
+
+	/* Enable the MSI interrupt */
+	writel(MSI_CTRL_INT, k1->link + INTR_ENABLE);
+
+	/* Top-level interrupt enable */
+	virt = k1->link + K1_PHY_AHB_IRQ_EN;
+	val = readl(virt);
+	val |= PCIE_INTERRUPT_EN;
+	writel(val, virt);
+}
+
+static void k1_pcie_disable_interrupts(struct k1_pcie *k1)
+{
+	void __iomem *virt;
+	u32 val;
+
+	virt = k1->link + K1_PHY_AHB_IRQ_EN;
+	val = readl(virt);
+	val &= ~PCIE_INTERRUPT_EN;
+	writel(val, virt);
+
+	writel(0, k1->link + INTR_ENABLE);
+}
+
+static bool k1_pcie_link_up(struct dw_pcie *pci)
+{
+	struct k1_pcie *k1 = to_k1_pcie(pci);
+	u32 val;
+
+	val = readl(k1->link + K1_PHY_AHB_LINK_STS);
+
+	return (val & RDLH_LINK_UP) && (val & SMLH_LINK_UP);
+}
+
+static int k1_pcie_start_link(struct dw_pcie *pci)
+{
+	struct k1_pcie *k1 = to_k1_pcie(pci);
+	int ret;
+
+	/* Stop holding the PHY in reset, and enable link training */
+	ret = regmap_update_bits(k1->pmu, k1->pmu_off + PCIE_CLK_RESET_CONTROL,
+				 APP_HOLD_PHY_RST | LTSSM_EN, LTSSM_EN);
+	if (ret)
+		return ret;
+
+	k1_pcie_enable_interrupts(k1);
+
+	return 0;
+}
+
+static void k1_pcie_stop_link(struct dw_pcie *pci)
+{
+	struct k1_pcie *k1 = to_k1_pcie(pci);
+	int ret;
+
+	k1_pcie_disable_interrupts(k1);
+
+	/* Disable the link and hold the PHY in reset */
+	ret = regmap_update_bits(k1->pmu, k1->pmu_off + PCIE_CLK_RESET_CONTROL,
+				 APP_HOLD_PHY_RST | LTSSM_EN, APP_HOLD_PHY_RST);
+	if (ret)
+		dev_err(pci->dev, "disable LTSSM failed (%d)\n", ret);
+}
+
+static const struct dw_pcie_ops k1_pcie_ops = {
+	.link_up	= k1_pcie_link_up,
+	.start_link	= k1_pcie_start_link,
+	.stop_link	= k1_pcie_stop_link,
+};
+
+static int k1_pcie_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct dw_pcie_rp *pp;
+	struct dw_pcie *pci;
+	struct k1_pcie *k1;
+	int ret;
+
+	k1 = devm_kzalloc(dev, sizeof(*k1), GFP_KERNEL);
+	if (!k1)
+		return -ENOMEM;
+	dev_set_drvdata(dev, k1);
+
+	k1->pmu = syscon_regmap_lookup_by_phandle_args(dev_of_node(dev),
+						       "spacemit,syscon-pmu",
+						       1, &k1->pmu_off);
+	if (IS_ERR(k1->pmu))
+		return dev_err_probe(dev, PTR_ERR(k1->pmu),
+				     "lookup PMU regmap failed\n");
+
+	k1->link = devm_platform_ioremap_resource_byname(pdev, "link");
+	if (!k1->link)
+		return dev_err_probe(dev, -ENOMEM, "map link regs failed\n");
+
+	k1->global_reset = devm_reset_control_get_shared(dev, "global");
+	if (IS_ERR(k1->global_reset))
+		return dev_err_probe(dev, PTR_ERR(k1->global_reset),
+				     "get global reset failed\n");
+
+	/* Hold the PHY in reset until we start the link */
+	ret = regmap_set_bits(k1->pmu, k1->pmu_off + PCIE_CLK_RESET_CONTROL,
+			      APP_HOLD_PHY_RST);
+	if (ret)
+		return dev_err_probe(dev, ret, "hold PHY in reset failed\n");
+
+	k1->phy = devm_phy_get(dev, NULL);
+	if (IS_ERR(k1->phy))
+		return dev_err_probe(dev, PTR_ERR(k1->phy), "get PHY failed\n");
+
+	pci = &k1->pci;
+	dw_pcie_cap_set(pci, REQ_RES);
+	pci->dev = dev;
+	pci->ops = &k1_pcie_ops;
+
+	pp = &pci->pp;
+	pp->num_vectors = MAX_MSI_IRQS;
+	pp->ops = &k1_pcie_host_ops;
+
+	ret = dw_pcie_host_init(pp);
+	if (ret)
+		return dev_err_probe(dev, ret, "host init failed\n");
+
+	return 0;
+}
+
+static void k1_pcie_remove(struct platform_device *pdev)
+{
+	struct k1_pcie *k1 = dev_get_drvdata(&pdev->dev);
+	struct dw_pcie_rp *pp = &k1->pci.pp;
+
+	dw_pcie_host_deinit(pp);
+}
+
+static const struct of_device_id k1_pcie_of_match_table[] = {
+	{ .compatible = "spacemit,k1-pcie-rc", },
+	{ },
+};
+
+static struct platform_driver k1_pcie_driver = {
+	.probe	= k1_pcie_probe,
+	.remove	= k1_pcie_remove,
+	.driver = {
+		.name			= "k1-dwc-pcie",
+		.of_match_table		= k1_pcie_of_match_table,
+		.suppress_bind_attrs	= true,
+	},
+};
+module_platform_driver(k1_pcie_driver);
-- 
2.48.1

[PATCH 6/6] riscv: dts: spacemit: PCIe and PHY-related updates

[Alex Elder]

Define PCIe and PHY-related Device Tree nodes for the SpacemiT K1 SoC.

Enable the combo PHY and the two PCIe-only PHYs on the Banana Pi BPI-F3
board.  The combo PHY is used for USB on this board, and that will be
enabled when USB 3 support is accepted.

Signed-off-by: Alex Elder <elder@riscstar.com>
---
 .../boot/dts/spacemit/k1-bananapi-f3.dts      |  28 +++
 arch/riscv/boot/dts/spacemit/k1-pinctrl.dtsi  |  33 ++++
 arch/riscv/boot/dts/spacemit/k1.dtsi          | 169 ++++++++++++++++++
 3 files changed, 230 insertions(+)

diff --git a/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts b/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts
index fe22c747c5012..1c75e38b1fab9 100644
--- a/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts
+++ b/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts
@@ -40,6 +40,34 @@ &emmc {
 	status = "okay";
 };
 
+&combo_phy {
+	pinctrl-names = "default";
+	pinctrl-0 = <&pcie0_3_cfg>;
+	status = "okay";
+};
+
+&pcie1_phy {
+	pinctrl-names = "default";
+	pinctrl-0 = <&pcie1_3_cfg>;
+	status = "okay";
+};
+
+&pcie2_phy {
+	pinctrl-names = "default";
+	pinctrl-0 = <&pcie2_4_cfg>;
+	status = "okay";
+};
+
+&pcie1 {
+	phys = <&pcie1_phy>;
+	status = "okay";
+};
+
+&pcie2 {
+	phys = <&pcie2_phy>;
+	status = "okay";
+};
+
 &uart0 {
 	pinctrl-names = "default";
 	pinctrl-0 = <&uart0_2_cfg>;
diff --git a/arch/riscv/boot/dts/spacemit/k1-pinctrl.dtsi b/arch/riscv/boot/dts/spacemit/k1-pinctrl.dtsi
index 3810557374228..e7dbecd7389b7 100644
--- a/arch/riscv/boot/dts/spacemit/k1-pinctrl.dtsi
+++ b/arch/riscv/boot/dts/spacemit/k1-pinctrl.dtsi
@@ -21,6 +21,39 @@ uart0-2-pins {
 		};
 	};
 
+	pcie0_3_cfg: pcie0-3-cfg {
+		pcie0-3-pins {
+			pinmux = <K1_PADCONF(54, 3)>,	/* PERST# */
+				 <K1_PADCONF(55, 3)>,	/* WAKE */
+				 <K1_PADCONF(53, 3)>;	/* CLKREQ# */
+
+			bias-pull-up = <0>;
+			drive-strength = <21>;
+		};
+	};
+
+	pcie1_3_cfg: pcie1-3-cfg {
+		pcie1-3-pins {
+			pinmux = <K1_PADCONF(59, 4)>,	/* PERST# */
+				 <K1_PADCONF(60, 4)>,	/* WAKE */
+				 <K1_PADCONF(61, 4)>;	/* CLKREQ# */
+
+			bias-pull-up = <0>;
+			drive-strength = <21>;
+		};
+	};
+
+	pcie2_4_cfg: pcie2-4-cfg {
+		pcie2-4-pins {
+			pinmux = <K1_PADCONF(62, 4)>,	/* PERST# */
+				 <K1_PADCONF(112, 3)>,	/* WAKE */
+				 <K1_PADCONF(117, 4)>;	/* CLKREQ# */
+
+			bias-pull-up = <0>;
+			drive-strength = <21>;
+		};
+	};
+
 	pwm14_1_cfg: pwm14-1-cfg {
 		pwm14-1-pins {
 			pinmux = <K1_PADCONF(44, 4)>;
diff --git a/arch/riscv/boot/dts/spacemit/k1.dtsi b/arch/riscv/boot/dts/spacemit/k1.dtsi
index abde8bb07c95c..6343f6e95284d 100644
--- a/arch/riscv/boot/dts/spacemit/k1.dtsi
+++ b/arch/riscv/boot/dts/spacemit/k1.dtsi
@@ -4,6 +4,8 @@
  */
 
 #include <dt-bindings/clock/spacemit,k1-syscon.h>
+#include <dt-bindings/gpio/gpio.h>
+#include <dt-bindings/phy/phy.h>
 
 /dts-v1/;
 / {
@@ -358,6 +360,42 @@ syscon_rcpu2: system-controller@c0888000 {
 			#reset-cells = <1>;
 		};
 
+		combo_phy: phy@c0b10000 {
+			compatible = "spacemit,k1-combo-phy";
+			reg = <0x0 0xc0b10000 0x0 0x1000>;
+			clocks = <&syscon_apmu CLK_PCIE0_DBI>,
+				 <&syscon_apmu CLK_PCIE0_MASTER>,
+				 <&syscon_apmu CLK_PCIE0_SLAVE>;
+			clock-names = "dbi",
+				      "mstr",
+				      "slv";
+			resets = <&syscon_apmu RESET_PCIE0_DBI>,
+				 <&syscon_apmu RESET_PCIE0_MASTER>,
+				 <&syscon_apmu RESET_PCIE0_SLAVE>,
+				 <&syscon_apmu RESET_PCIE0_GLOBAL>;
+			reset-names = "dbi",
+				      "mstr",
+				      "slv",
+				      "global";
+			spacemit,syscon-pmu = <&syscon_apmu>;
+			#phy-cells = <1>;
+			status = "disabled";
+		};
+
+		pcie1_phy: phy@c0c10000 {
+			compatible = "spacemit,k1-pcie-phy";
+			reg = <0x0 0xc0c10000 0x0 0x1000>;
+			#phy-cells = <0>;
+			status = "disabled";
+		};
+
+		pcie2_phy: phy@c0d10000 {
+			compatible = "spacemit,k1-pcie-phy";
+			reg = <0x0 0xc0d10000 0x0 0x1000>;
+			#phy-cells = <0>;
+			status = "disabled";
+		};
+
 		syscon_apbc: system-controller@d4015000 {
 			compatible = "spacemit,k1-syscon-apbc";
 			reg = <0x0 0xd4015000 0x0 0x1000>;
@@ -814,6 +852,137 @@ pcie-bus {
 			#size-cells = <2>;
 			dma-ranges = <0x0 0x00000000 0x0 0x00000000 0x0 0x80000000>,
 				     <0x0 0xb8000000 0x1 0x38000000 0x3 0x48000000>;
+			pcie0: pcie@ca000000 {
+				compatible = "spacemit,k1-pcie-rc";
+				reg = <0x0 0xca000000 0x0 0x00001000>,
+				      <0x0 0xca300000 0x0 0x0001ff24>,
+				      <0x0 0x8f000000 0x0 0x00002000>,
+				      <0x0 0xc0b20000 0x0 0x00001000>;
+				reg-names = "dbi",
+					    "atu",
+					    "config",
+					    "link";
+				spacemit,syscon-pmu = <&syscon_apmu 0x03cc>;
+
+				ranges = <0x01000000 0x0 0x8f002000 0 0x8f002000 0x0 0x100000>,
+					 <0x02000000 0x0 0x80000000 0 0x80000000 0x0 0x0f000000>;
+
+				clocks = <&syscon_apmu CLK_PCIE0_DBI>,
+					 <&syscon_apmu CLK_PCIE0_MASTER>,
+					 <&syscon_apmu CLK_PCIE0_SLAVE>;
+				clock-names = "dbi",
+					      "mstr",
+					      "slv";
+
+				resets = <&syscon_apmu RESET_PCIE0_DBI>,
+					 <&syscon_apmu RESET_PCIE0_MASTER>,
+					 <&syscon_apmu RESET_PCIE0_SLAVE>,
+					 <&syscon_apmu RESET_PCIE0_GLOBAL>;
+				reset-names = "dbi",
+					      "mstr",
+					      "slv",
+					      "global";
+
+				interrupts-extended = <&plic 141>;
+
+				#address-cells = <3>;
+				#size-cells = <2>;
+
+				device_type = "pci";
+				max-link-speed = <2>;
+				bus-range = <0x00 0xff>;
+				num-viewport = <8>;
+
+				status = "disabled";
+			};
+
+			pcie1: pcie@ca400000 {
+				compatible = "spacemit,k1-pcie-rc";
+				reg = <0x0 0xca400000 0x0 0x00001000>,
+				      <0x0 0xca700000 0x0 0x0001ff24>,
+				      <0x0 0x9f000000 0x0 0x00002000>,
+				      <0x0 0xc0c20000 0x0 0x00001000>;
+				reg-names = "dbi",
+					    "atu",
+					    "config",
+					    "link";
+				spacemit,syscon-pmu = <&syscon_apmu 0x3d4>;
+
+				ranges = <0x01000000 0x0 0x9f002000 0 0x9f002000 0x0 0x100000>,
+					 <0x02000000 0x0 0x90000000 0 0x90000000 0x0 0x0f000000>;
+				clocks = <&syscon_apmu CLK_PCIE1_DBI>,
+					 <&syscon_apmu CLK_PCIE1_MASTER>,
+					 <&syscon_apmu CLK_PCIE1_SLAVE>;
+				clock-names = "dbi",
+					      "mstr",
+					      "slv";
+
+				resets = <&syscon_apmu RESET_PCIE1_DBI>,
+					 <&syscon_apmu RESET_PCIE1_MASTER>,
+					 <&syscon_apmu RESET_PCIE1_SLAVE>,
+					 <&syscon_apmu RESET_PCIE1_GLOBAL>;
+				reset-names = "dbi",
+					      "mstr",
+					      "slv",
+					      "global";
+
+				interrupts-extended = <&plic 142>;
+
+				#address-cells = <3>;
+				#size-cells = <2>;
+
+				device_type = "pci";
+				max-link-speed = <2>;
+				bus-range = <0x00 0xff>;
+				num-viewport = <8>;
+
+				status = "disabled";
+			};
+
+			pcie2: pcie@ca800000 {
+				compatible = "spacemit,k1-pcie-rc";
+				reg = <0x0 0xca800000 0x0 0x00001000>,
+				      <0x0 0xcab00000 0x0 0x0001ff24>,
+				      <0x0 0xb7000000 0x0 0x00002000>,
+				      <0x0 0xc0d20000 0x0 0x00001000>;
+				reg-names = "dbi",
+					    "atu",
+					    "config",
+					    "link";
+
+				spacemit,syscon-pmu = <&syscon_apmu 0x3dc>;
+
+				ranges = <0x01000000 0x0 0xb7002000 0 0xb7002000 0x0 0x100000>,
+					 <0x42000000 0x0 0xa0000000 0 0xa0000000 0x0 0x10000000>,
+					 <0x02000000 0x0 0xb0000000 0 0xb0000000 0x0 0x7000000>;
+				clocks = <&syscon_apmu CLK_PCIE2_DBI>,
+					 <&syscon_apmu CLK_PCIE2_MASTER>,
+					 <&syscon_apmu CLK_PCIE2_SLAVE>;
+				clock-names = "dbi",
+					      "mstr",
+					      "slv";
+
+				resets = <&syscon_apmu RESET_PCIE2_DBI>,
+					 <&syscon_apmu RESET_PCIE2_MASTER>,
+					 <&syscon_apmu RESET_PCIE2_SLAVE>,
+					 <&syscon_apmu RESET_PCIE2_GLOBAL>;
+				reset-names = "dbi",
+					      "mstr",
+					      "slv",
+					      "global";
+
+				interrupts-extended = <&plic 143>;
+
+				#address-cells = <3>;
+				#size-cells = <2>;
+
+				device_type = "pci";
+				max-link-speed = <2>;
+				bus-range = <0x00 0xff>;
+				num-viewport = <8>;
+
+				status = "disabled";
+			};
 		};
 
 		storage-bus {
-- 
2.48.1

Re: [PATCH 3/6] dt-bindings: phy: spacemit: introduce PCIe root complex

[Rob Herring (Arm)]

On Wed, 13 Aug 2025 13:46:57 -0500, Alex Elder wrote:
> Add the Device Tree binding for the PCIe root complex found on the
> SpacemiT K1 SoC.  This device is derived from the Synopsys Designware
> PCIe IP.  It supports up to three PCIe ports operating at PCIe gen 2
> link speeds (5 GT/sec).  One of the ports uses a combo PHY, which is
> typically used to support a USB 3 port.
> 
> Signed-off-by: Alex Elder <elder@riscstar.com>
> ---
>  .../bindings/pci/spacemit,k1-pcie-rc.yaml     | 141 ++++++++++++++++++
>  1 file changed, 141 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/pci/spacemit,k1-pcie-rc.yaml
> 

My bot found errors running 'make dt_binding_check' on your patch:

yamllint warnings/errors:

dtschema/dtc warnings/errors:
Documentation/devicetree/bindings/pci/spacemit,k1-pcie-rc.example.dtb: /example-0/pcie@ca000000: failed to match any schema with compatible: ['spacemit,k1-pcie-rc']

doc reference errors (make refcheckdocs):

See https://patchwork.ozlabs.org/project/devicetree-bindings/patch/20250813184701.2444372-4-elder@riscstar.com

The base for the series is generally the latest rc1. A different dependency
should be noted in *this* patch.

If you already ran 'make dt_binding_check' and didn't see the above
error(s), then make sure 'yamllint' is installed and dt-schema is up to
date:

pip3 install dtschema --upgrade

Please check and re-submit after running the above command yourself. Note
that DT_SCHEMA_FILES can be set to your schema file to speed up checking
your schema. However, it must be unset to test all examples with your schema.

Re: [PATCH 3/6] dt-bindings: phy: spacemit: introduce PCIe root complex

[Alex Elder]

On 8/13/25 3:49 PM, Rob Herring (Arm) wrote:
> 
> On Wed, 13 Aug 2025 13:46:57 -0500, Alex Elder wrote:
>> Add the Device Tree binding for the PCIe root complex found on the
>> SpacemiT K1 SoC.  This device is derived from the Synopsys Designware
>> PCIe IP.  It supports up to three PCIe ports operating at PCIe gen 2
>> link speeds (5 GT/sec).  One of the ports uses a combo PHY, which is
>> typically used to support a USB 3 port.
>>
>> Signed-off-by: Alex Elder <elder@riscstar.com>
>> ---
>>   .../bindings/pci/spacemit,k1-pcie-rc.yaml     | 141 ++++++++++++++++++
>>   1 file changed, 141 insertions(+)
>>   create mode 100644 Documentation/devicetree/bindings/pci/spacemit,k1-pcie-rc.yaml
>>
> 
> My bot found errors running 'make dt_binding_check' on your patch:

Mine didn't for some reason, so I must be doing something wrong.

Simple inspection shows my compatible string contains ".yaml"!

I'll fix in a new version.  Sorry I missed this.

					-Alex

> yamllint warnings/errors:
> 
> dtschema/dtc warnings/errors:
> Documentation/devicetree/bindings/pci/spacemit,k1-pcie-rc.example.dtb: /example-0/pcie@ca000000: failed to match any schema with compatible: ['spacemit,k1-pcie-rc']
> 
> doc reference errors (make refcheckdocs):
> 
> See https://patchwork.ozlabs.org/project/devicetree-bindings/patch/20250813184701.2444372-4-elder@riscstar.com
> 
> The base for the series is generally the latest rc1. A different dependency
> should be noted in *this* patch.
> 
> If you already ran 'make dt_binding_check' and didn't see the above
> error(s), then make sure 'yamllint' is installed and dt-schema is up to
> date:
> 
> pip3 install dtschema --upgrade
> 
> Please check and re-submit after running the above command yourself. Note
> that DT_SCHEMA_FILES can be set to your schema file to speed up checking
> your schema. However, it must be unset to test all examples with your schema.
> 

Re: [PATCH 5/6] PCI: spacemit: introduce SpacemiT PCIe host driver

[Bjorn Helgaas]

On Wed, Aug 13, 2025 at 01:46:59PM -0500, Alex Elder wrote:
> Introduce a driver for the PCIe root complex found in the SpacemiT
> K1 SoC.  The hardware is derived from the Synopsys DesignWare PCIe IP.
> The driver supports three PCIe ports that operate at PCIe v2 transfer
> rates (5 GT/sec).  The first port uses a combo PHY, which may be
> configured for use for USB 3 instead.

I assume "PCIe v2" means what most people call "PCIe gen2", but the
spec encourages avoidance "genX" because it's ambiguous.

> +config PCIE_K1
> +	bool "SpacemiT K1 host mode PCIe controller"

Style of nearby entries is:

  "SpacemiT K1 PCIe controller (host mode)"

Please alphabetize by the company name ("SpacemiT") in the menu entry.

> +#define K1_PCIE_VENDOR_ID	0x201f
> +#define K1_PCIE_DEVICE_ID	0x0001

I assume this (0x201f) has been reserved by the PCI-SIG?  I don't see
it at:

  https://pcisig.com/membership/member-companies?combine=0x201f

Possibly rename this to PCI_VENDOR_ID_K1 (or maybe
PCI_VENDOR_ID_SPACEMIT?) to match the usual format in
include/linux/pci_ids.h, since it seems likely to end up there
eventually.

> +#define PCIE_RC_PERST			BIT(12)	/* 0: PERST# high; 1: low */

Maybe avoid confusion by describing as "1: assert PERST#" or similar?

> +	/* Wait the PCIe-mandated 100 msec before deasserting PERST# */
> +	mdelay(100);

I think this is PCIE_T_PVPERL_MS.  Comment is superfluous then.

> +static int k1_pcie_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct dw_pcie_rp *pp;
> +	struct dw_pcie *pci;
> +	struct k1_pcie *k1;
> +	int ret;
> +
> +	k1 = devm_kzalloc(dev, sizeof(*k1), GFP_KERNEL);
> +	if (!k1)
> +		return -ENOMEM;
> +	dev_set_drvdata(dev, k1);

Most neighboring drivers use platform_set_drvdata().  Personally, I
would set drvdata after initializing k1 because I don't like to
advertise pointers to uninitialized things.

> +static void k1_pcie_remove(struct platform_device *pdev)
> +{
> +	struct k1_pcie *k1 = dev_get_drvdata(&pdev->dev);

Neighbors use platform_get_drvdata().

> +	struct dw_pcie_rp *pp = &k1->pci.pp;
> +
> +	dw_pcie_host_deinit(pp);
> +}

Re: [PATCH 5/6] PCI: spacemit: introduce SpacemiT PCIe host driver

[Alex Elder]

On 8/13/25 4:22 PM, Bjorn Helgaas wrote:
> On Wed, Aug 13, 2025 at 01:46:59PM -0500, Alex Elder wrote:
>> Introduce a driver for the PCIe root complex found in the SpacemiT
>> K1 SoC.  The hardware is derived from the Synopsys DesignWare PCIe IP.
>> The driver supports three PCIe ports that operate at PCIe v2 transfer
>> rates (5 GT/sec).  The first port uses a combo PHY, which may be
>> configured for use for USB 3 instead.
> 
> I assume "PCIe v2" means what most people call "PCIe gen2", but the
> spec encourages avoidance "genX" because it's ambiguous.

Yes, that's what I meant, but I did try to clarify with the
transfer rate.

>> +config PCIE_K1
>> +	bool "SpacemiT K1 host mode PCIe controller"
> 
> Style of nearby entries is:
> 
>    "SpacemiT K1 PCIe controller (host mode)"

OK I'll fix that.

> Please alphabetize by the company name ("SpacemiT") in the menu entry.

OK.

>> +#define K1_PCIE_VENDOR_ID	0x201f
>> +#define K1_PCIE_DEVICE_ID	0x0001
> 
> I assume this (0x201f) has been reserved by the PCI-SIG?  I don't see
> it at:
> 
>    https://pcisig.com/membership/member-companies?combine=0x201f

I hadn't even thought to check that.  I will follow up.  Thanks
for pointing this out.

> Possibly rename this to PCI_VENDOR_ID_K1 (or maybe
> PCI_VENDOR_ID_SPACEMIT?) to match the usual format in
> include/linux/pci_ids.h, since it seems likely to end up there
> eventually.

OK.

>> +#define PCIE_RC_PERST			BIT(12)	/* 0: PERST# high; 1: low */
> 
> Maybe avoid confusion by describing as "1: assert PERST#" or similar?

OK.  I struggled with how to express this to avoid confusion.
But I do think "assert PERST#" is better.

>> +	/* Wait the PCIe-mandated 100 msec before deasserting PERST# */
>> +	mdelay(100);
> 
> I think this is PCIE_T_PVPERL_MS.  Comment is superfluous then.

Excellent, thank you, I'll use that.

>> +static int k1_pcie_probe(struct platform_device *pdev)
>> +{
>> +	struct device *dev = &pdev->dev;
>> +	struct dw_pcie_rp *pp;
>> +	struct dw_pcie *pci;
>> +	struct k1_pcie *k1;
>> +	int ret;
>> +
>> +	k1 = devm_kzalloc(dev, sizeof(*k1), GFP_KERNEL);
>> +	if (!k1)
>> +		return -ENOMEM;
>> +	dev_set_drvdata(dev, k1);
> 
> Most neighboring drivers use platform_set_drvdata().  Personally, I
> would set drvdata after initializing k1 because I don't like to
> advertise pointers to uninitialized things.

OK, I understand that and will do it the way you suggest.

>> +static void k1_pcie_remove(struct platform_device *pdev)
>> +{
>> +	struct k1_pcie *k1 = dev_get_drvdata(&pdev->dev);
> 
> Neighbors use platform_get_drvdata().

Yes, that goes with platform_set_drvdata().

>> +	struct dw_pcie_rp *pp = &k1->pci.pp;
>> +
>> +	dw_pcie_host_deinit(pp);
>> +}

Thank you very much for your review.

					-Alex

Re: [PATCH 4/6] phy: spacemit: introduce PCIe/combo PHY

[Inochi Amaoto]

On Wed, Aug 13, 2025 at 01:46:58PM -0500, Alex Elder wrote:
> Introduce a driver that supports three PHYs found on the SpacemiT
> K1 SoC.  The first PHY is a combo PHY that can be configured for
> use for either USB 3 or PCIe.  The other two PHYs support PCIe
> only.
> 
> All three PHYs must be programmed with an 8 bit receiver termination
> value, which must be determined dynamically; only the combo PHY is
> able to determine this value.  The combo PHY performs a special
> calibration step at probe time to discover this, and that value is
> used to program each PHY that operates in PCIe mode.  The combo
> PHY must therefore be probed--first--if either of the PCIe-only
> PHYs will be used.
> 
> During normal operation, the USB or PCIe driver using the PHY must
> ensure clocks and resets are set up properly.  However clocks are
> enabled and resets are de-asserted temporarily by this driver to
> perform the calibration step on the combo PHY.
> 
> Tested-by: Junzhong Pan <panjunzhong@linux.spacemit.com>
> Signed-off-by: Alex Elder <elder@riscstar.com>
> ---
>  drivers/phy/Kconfig                |  11 +
>  drivers/phy/Makefile               |   1 +
>  drivers/phy/phy-spacemit-k1-pcie.c | 639 +++++++++++++++++++++++++++++
>  3 files changed, 651 insertions(+)
>  create mode 100644 drivers/phy/phy-spacemit-k1-pcie.c
> 
> diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
> index 58c911e1b2d20..0fa343203f289 100644
> --- a/drivers/phy/Kconfig
> +++ b/drivers/phy/Kconfig
> @@ -101,6 +101,17 @@ config PHY_NXP_PTN3222
>  	  schemes. It supports all three USB 2.0 data rates: Low Speed, Full
>  	  Speed and High Speed.
>  
> +config PHY_SPACEMIT_K1_PCIE
> +	tristate "PCIe and combo PHY driver for the SpacemiT K1 SoC"
> +	depends on ARCH_SPACEMIT || COMPILE_TEST
> +	depends on HAS_IOMEM
> +	depends on OF
> +	select GENERIC_PHY
> +	default ARCH_SPACEMIT
> +	help
> +	  Enable support for the PCIe and USB 3 combo PHY and two
> +	  PCIe-only PHYs used in the SpacemiT K1 SoC.
> +
>  source "drivers/phy/allwinner/Kconfig"
>  source "drivers/phy/amlogic/Kconfig"
>  source "drivers/phy/broadcom/Kconfig"
> diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
> index c670a8dac4680..20f0078e543c7 100644
> --- a/drivers/phy/Makefile
> +++ b/drivers/phy/Makefile
> @@ -13,6 +13,7 @@ obj-$(CONFIG_PHY_SNPS_EUSB2)		+= phy-snps-eusb2.o
>  obj-$(CONFIG_USB_LGM_PHY)		+= phy-lgm-usb.o
>  obj-$(CONFIG_PHY_AIROHA_PCIE)		+= phy-airoha-pcie.o
>  obj-$(CONFIG_PHY_NXP_PTN3222)		+= phy-nxp-ptn3222.o
> +obj-$(CONFIG_PHY_SPACEMIT_K1_PCIE)	+= phy-spacemit-k1-pcie.o
>  obj-y					+= allwinner/	\
>  					   amlogic/	\
>  					   broadcom/	\
> diff --git a/drivers/phy/phy-spacemit-k1-pcie.c b/drivers/phy/phy-spacemit-k1-pcie.c
> new file mode 100644
> index 0000000000000..32dce53170fbb
> --- /dev/null
> +++ b/drivers/phy/phy-spacemit-k1-pcie.c
> @@ -0,0 +1,639 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * SpacemiT K1 PCIe and PCIe/USB 3 combo PHY driver
> + *
> + * Copyright (C) 2025 by RISCstar Solutions Corporation.  All rights reserved.
> + */
> +
> +#include <linux/bitfield.h>
> +#include <linux/clk.h>
> +#include <linux/iopoll.h>
> +#include <linux/kernel.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/module.h>
> +#include <linux/phy/phy.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +#include <linux/reset.h>
> +
> +#include <dt-bindings/phy/phy.h>
> +
> +/*
> + * Three PCIe ports are supported in the SpacemiT K1 SoC, and this driver
> + * supports their PHYs.
> + *
> + * The PHY for PCIe port A is different from the PHYs for ports B and C:
> + * - It has one lane, while ports B and C have two
> + * - It is a combo PHY can be used for PCIe or USB 3
> + * - It can automatically calibrate PCIe TX and RX termination settings
> + *
> + * The PHY functionality for PCIe ports B and C is identical:
> + * - They have two PCIe lanes (but can be restricted to 1 via Device Tree)
> + * - They are used for PCIe only
> + * - They are configured using TX and RX values computed for port A
> + *
> + * A given board is designed to use the combo PHY for either PCIe or USB 3.
> + * Whether the combo PHY is configured for PCIe or USB 3 is specified in
> + * Device Tree using a phandle plus an argument.  The argument indicates
> + * the type (either PHY_TYPE_PCIE or PHY_TYPE_USB3).
> + *
> + * Each PHY depends on clocks and resets provided by the controller
> + * hardware (PCIe or USB) it is associated with.  The controller drivers
> + * are required to enable any clocks and de-assert any resets that affect
> + * PHY operation.
> + *
> + * PCIe PHYs must be programmed with RX and TX calibration values.  The
> + * combo PHY is the only one that can determine these values.  They are
> + * determined by temporarily enabling the combo PHY in PCIe mode at probe
> + * time (if necessary).  This calibration only needs to be done once, and
> + * when it has completed the TX and RX values are saved.
> + *
> + * To allow the combo PHY to be enabled for calibration, the resets and
> + * clocks it uses in PCIe mode must be supplied.
> + */
> +
> +struct k1_pcie_phy {
> +	struct device *dev;		/* PHY provider device */
> +	struct phy *phy;
> +	void __iomem *regs;
> +	u32 pcie_lanes;			/* Max unless limited by DT */
> +	/* The remaining fields are only used for the combo PHY */
> +	u32 type;			/* PHY_TYPE_PCIE or PHY_TYPE_USB3 */
> +	struct regmap *pmu;
> +};
> +
> +#define CALIBRATION_TIMEOUT		500000	/* microseconds */
> +#define PLL_TIMEOUT			500000	/* microseconds */
> +#define POLL_DELAY			500	/* microseconds */
> +
> +/* Selecting the combo PHY operating mode requires PMU regmap access */
> +#define SYSCON_PMU			"spacemit,syscon-pmu"
> +
> +/* PMU space, for selecting between PCIe and USB3 mode on the combo PHY */
> +
> +#define PMUA_USB_PHY_CTRL0			0x0110
> +#define COMBO_PHY_SEL			BIT(3)	/* 0: PCIe; 1: USB3 */
> +
> +#define PCIE_CLK_RES_CTRL			0x03cc
> +#define PCIE_APP_HOLD_PHY_RST		BIT(30)
> +
> +/* PHY register space */
> +
> +/* Offset between lane 0 and lane 1 registers when there are two */
> +#define PHY_LANE_OFFSET				0x0400
> +
> +#define PCIE_PU_ADDR_CLK_CFG			0x0008
> +#define PLL_READY			BIT(0)		/* read-only */
> +#define CFG_RXCLK_EN			BIT(3)
> +#define CFG_TXCLK_EN			BIT(4)
> +#define CFG_PCLK_EN			BIT(5)
> +#define CFG_PIPE_PCLK_EN		BIT(6)
> +#define CFG_INTERNAL_TIMER_ADJ		GENMASK(10, 7)
> +#define TIMER_ADJ_USB		0x2
> +#define TIMER_ADJ_PCIE		0x6
> +#define CFG_SW_PHY_INIT_DONE		BIT(11)	/* We set after PLL config */
> +
> +#define PCIE_RC_DONE_STATUS			0x0018
> +#define CFG_FORCE_RCV_RETRY		BIT(10)
> +
> +#define PCIE_RC_CAL_REG2			0x0020
> +#define RC_CAL_TOGGLE			BIT(22)
> +#define CLKSEL				GENMASK(31, 29)
> +#define CLKSEL_24M		0x3
> +
> +#define PCIE_PU_PLL_1				0x0048
> +#define REF_100_WSSC			BIT(12)	/* 1: input is 100MHz, SSC */
> +#define FREF_SEL			GENMASK(15, 13)
> +#define FREF_24M		0x1
> +#define SSC_DEP_SEL			GENMASK(19, 16)
> +#define SSC_DEP_NONE		0x0
> +#define SSC_DEP_5000PPM		0xa
> +#define SSC_MODE			GENMASK(21, 20)
> +#define SSC_MODE_DOWN_SPREAD	0x3
> +#define SSC_OFFSET			GENMASK(23, 22)
> +#define SSC_OFFSET_0_PPM	0x0
> +
> +#define PCIE_PU_PLL_2				0x004c
> +#define GEN_REF100			BIT(4)	/* 1: generate 100MHz clk */
> +
> +#define PCIE_RX_REG1				0x0050
> +#define EN_RTERM			BIT(3)
> +#define AFE_RTERM_REG			GENMASK(11, 8)
> +
> +#define PCIE_RX_REG2				0x0054
> +#define RX_RTERM_SEL			BIT(5)	/* 0: use AFE_RTERM_REG value */
> +
> +#define PCIE_LTSSM_DIS_ENTRY			0x005c
> +#define CFG_REFCLK_MODE			GENMASK(9, 8)
> +#define RFCLK_MODE_DRIVER	0x1
> +#define OVRD_REFCLK_MODE		BIT(10)	/* 1: use CFG_RFCLK_MODE */
> +
> +#define PCIE_TX_REG1				0x0064
> +#define TX_RTERM_REG			GENMASK(15, 12)
> +#define TX_RTERM_SEL			BIT(25)	/* 1: use TX_RTERM_REG */
> +
> +#define USB3_TEST_CTRL				0x0068
> +
> +#define PCIE_RCAL_RESULT			0x0084	/* Port A PHY only */
> +#define RTERM_VALUE_RX			GENMASK(3, 0)
> +#define RTERM_VALUE_TX			GENMASK(7, 4)
> +#define R_TUNE_DONE			BIT(10)
> +
> +static u32 k1_phy_rterm = ~0;     /* Invalid initial value */
> +
> +/* Save the RX and TX receiver termination values */
> +static void k1_phy_rterm_set(u32 val)
> +{
> +	k1_phy_rterm = val & (RTERM_VALUE_RX | RTERM_VALUE_TX);
> +}
> +
> +static bool k1_phy_rterm_valid(void)
> +{
> +	/* Valid if no bits outside those we care about are set */
> +	return !(k1_phy_rterm & ~(RTERM_VALUE_RX | RTERM_VALUE_TX));
> +}
> +
> +static u32 k1_phy_rterm_rx(void)
> +{
> +	return FIELD_GET(RTERM_VALUE_RX, k1_phy_rterm);
> +}
> +
> +static u32 k1_phy_rterm_tx(void)
> +{
> +	return FIELD_GET(RTERM_VALUE_TX, k1_phy_rterm);
> +}
> +
> +/* Only the combo PHY has a PMU pointer defined */
> +static bool k1_phy_port_a(struct k1_pcie_phy *k1_phy)
> +{
> +	return !!k1_phy->pmu;
> +}
> +
> +/*
> + * Select PCIe or USB 3 mode for the combo PHY.  Return 1 if the bit
> + * was changed, 0 if it was not, or a negative error value otherwise.
> + */
> +static int k1_combo_phy_sel(struct k1_pcie_phy *k1_phy, bool usb3)
> +{
> +	int ret;
> +
> +	ret = regmap_test_bits(k1_phy->pmu, PMUA_USB_PHY_CTRL0, COMBO_PHY_SEL);
> +	if (ret < 0)
> +		return ret;
> +
> +	/* If it's already in the desired state, we're done */
> +	if (!!ret == usb3)
> +		return 0;
> +
> +	/* Change the bit */
> +	ret = regmap_assign_bits(k1_phy->pmu, PMUA_USB_PHY_CTRL0,
> +				 COMBO_PHY_SEL, usb3);
> +
> +	return ret < 0 ? ret : 1;
> +}
> +

> +static void k1_pcie_phy_init_pll(struct k1_pcie_phy *k1_phy,
> +				 void __iomem *regs, bool pcie)
> +{
> +	void __iomem *virt;
> +	u32 timer_adj;
> +	u32 ssc_dep;
> +	u32 val;
> +
> +	if (pcie) {
> +		timer_adj = TIMER_ADJ_PCIE;
> +		ssc_dep = SSC_DEP_NONE;
> +	} else {
> +		timer_adj = TIMER_ADJ_USB;
> +		ssc_dep = SSC_DEP_5000PPM;
> +	}
> +
> +	/*
> +	 * Disable 100 MHz input reference with spread-spectrum
> +	 * clocking and select the 24 MHz clock input frequency
> +	 */
> +	virt = k1_phy->regs + PCIE_PU_PLL_1;
> +	val = readl(virt);
> +	val &= ~REF_100_WSSC;
> +
> +	val &= ~FREF_SEL;
> +	val |= FIELD_PREP(FREF_SEL, FREF_24M);
> +
> +	val &= ~SSC_DEP_SEL;
> +	val |= FIELD_PREP(SSC_DEP_SEL, ssc_dep);
> +
> +	val &= ~SSC_MODE;
> +	val |= FIELD_PREP(SSC_MODE, SSC_MODE_DOWN_SPREAD);
> +
> +	val &= ~SSC_OFFSET;
> +	val |= FIELD_PREP(SSC_OFFSET, SSC_OFFSET_0_PPM);
> +	writel(val, virt);
> +
> +	if (pcie) {
> +		virt = regs + PCIE_PU_PLL_2;
> +		val = readl(virt);
> +		val |= GEN_REF100;	/* Enable 100 MHz PLL output clock */
> +		writel(val, virt);
> +	}
> +
> +	/* Enable clocks and mark PLL initialization done */
> +	virt = regs + PCIE_PU_ADDR_CLK_CFG;
> +	val = readl(virt);
> +	val |= CFG_RXCLK_EN;
> +	val |= CFG_TXCLK_EN;
> +	val |= CFG_PCLK_EN;
> +	val |= CFG_PIPE_PCLK_EN;
> +
> +	val &= ~CFG_INTERNAL_TIMER_ADJ;
> +	val |= FIELD_PREP(CFG_INTERNAL_TIMER_ADJ, timer_adj);
> +
> +	val |= CFG_SW_PHY_INIT_DONE;
> +	writel(val, virt);
> +}
> +
> +static int k1_pcie_pll_lock(struct k1_pcie_phy *k1_phy, bool pcie)
> +{
> +	u32 val = pcie ? CFG_FORCE_RCV_RETRY : 0;
> +	void __iomem *virt;
> +
> +	writel(val, k1_phy->regs + PCIE_RC_DONE_STATUS);
> +
> +	/*
> +	 * Wait for indication the PHY PLL is locked.  Lanes for ports
> +	 * B and C share a PLL, so it's enough to sample just lane 0.
> +	 */
> +	virt = k1_phy->regs + PCIE_PU_ADDR_CLK_CFG;	/* Lane 0 */
> +
> +	return readl_poll_timeout(virt, val, val & PLL_READY,
> +				  POLL_DELAY, PLL_TIMEOUT);
> +}
> +

Can we use standard clk_ops and clk_mux to normalize this process?

Regards,
Inochi

Re: [PATCH 1/6] dt-bindings: phy: spacemit: add SpacemiT PCIe/combo PHY

[Yao Zi]

On Wed, Aug 13, 2025 at 01:46:55PM -0500, Alex Elder wrote:
> Add the Device Tree binding for the PCIe/USB 3.0 combo PHY found in
> the SpacemiT K1 SoC.  This is one of three PCIe PHYs, and is unusual
> in that only the combo PHY can perform a calibration step needed to
> determine settings used by the other two PCIe PHYs.
> 
> Calibration must be done with the combo PHY in PCIe mode, and to allow
> this to occur independent of the eventual use for the PHY (PCIe or USB)
> some PCIe-related properties must be supplied: clocks; resets; and a
> syscon phandle.
> 
> Signed-off-by: Alex Elder <elder@riscstar.com>
> ---
>  .../bindings/phy/spacemit,k1-combo-phy.yaml   | 110 ++++++++++++++++++
>  1 file changed, 110 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/phy/spacemit,k1-combo-phy.yaml
> 
> diff --git a/Documentation/devicetree/bindings/phy/spacemit,k1-combo-phy.yaml b/Documentation/devicetree/bindings/phy/spacemit,k1-combo-phy.yaml
> new file mode 100644
> index 0000000000000..ed78083a53231
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/phy/spacemit,k1-combo-phy.yaml

...

> +  spacemit,syscon-pmu:
> +    description:
> +      PHandle that refers to the APMU system controller, whose
> +      regmap is used in setting the mode
> +    $ref: /schemas/types.yaml#/definitions/phandle

Clock controllers and ethernet controllers all use spacemit,apmu to
refer the APMU system controller. Do you think it's better to keep them
aligned?

...

> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/clock/spacemit,k1-syscon.h>
> +    combo_phy: phy@c0b10000 {

This label is unnecessary.

> +        compatible = "spacemit,k1-combo-phy";
> +        reg = <0xc0b10000 0x1000>;
> +        clocks = <&syscon_apmu CLK_PCIE0_DBI>,
> +                 <&syscon_apmu CLK_PCIE0_MASTER>,
> +                 <&syscon_apmu CLK_PCIE0_SLAVE>;
> +        clock-names = "dbi",
> +                      "mstr",
> +                      "slv";
> +        resets = <&syscon_apmu RESET_PCIE0_DBI>,
> +                 <&syscon_apmu RESET_PCIE0_MASTER>,
> +                 <&syscon_apmu RESET_PCIE0_SLAVE>,
> +                 <&syscon_apmu RESET_PCIE0_GLOBAL>;
> +        reset-names = "dbi",
> +                      "mstr",
> +                      "slv",
> +                      "global";
> +        spacemit,syscon-pmu = <&syscon_apmu>;
> +        #phy-cells = <1>;
> +        status = "disabled";
> +    };

Best regards,
Yao Zi

Re: [PATCH 1/6] dt-bindings: phy: spacemit: add SpacemiT PCIe/combo PHY

[Krzysztof Kozlowski]

On 13/08/2025 20:46, Alex Elder wrote:
> +                      "mstr",
> +                      "slv",
> +                      "global";
> +        spacemit,syscon-pmu = <&syscon_apmu>;
> +        #phy-cells = <1>;
> +        status = "disabled";

You cannot have disabled examples. This also means it could not be
checked/tested.

> +    };


Best regards,
Krzysztof

Re: [PATCH 2/6] dt-bindings: phy: spacemit: introduce PCIe PHY

[Krzysztof Kozlowski]

On 13/08/2025 20:46, Alex Elder wrote:
> +
> +required:
> +  - compatible
> +  - reg
> +  - "#phy-cells"
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/clock/spacemit,k1-syscon.h>
> +    pcie1_phy: phy@c0c10000 {
> +        compatible = "spacemit,k1-pcie-phy";
> +        reg = <0xc0c10000 0x1000>;
> +        #phy-cells = <0>;
> +        status = "disabled";
Same problem here.

Best regards,
Krzysztof

Re: [PATCH 1/6] dt-bindings: phy: spacemit: add SpacemiT PCIe/combo PHY

[Alex Elder]

On 8/14/25 1:11 AM, Krzysztof Kozlowski wrote:
> On 13/08/2025 20:46, Alex Elder wrote:
>> +                      "mstr",
>> +                      "slv",
>> +                      "global";
>> +        spacemit,syscon-pmu = <&syscon_apmu>;
>> +        #phy-cells = <1>;
>> +        status = "disabled";
> 
> You cannot have disabled examples. This also means it could not be
> checked/tested.
> 
>> +    };
> 
> 
> Best regards,
> Krzysztof

OK I'll fix that in both places.  I think I just copied in the
actual DTS content, but I now understand the problem.

Thanks.

					-Alex

Re: [PATCH 4/6] phy: spacemit: introduce PCIe/combo PHY

[Alex Elder]

On 8/13/25 6:42 PM, Inochi Amaoto wrote:
> On Wed, Aug 13, 2025 at 01:46:58PM -0500, Alex Elder wrote:
>> Introduce a driver that supports three PHYs found on the SpacemiT
>> K1 SoC.  The first PHY is a combo PHY that can be configured for
>> use for either USB 3 or PCIe.  The other two PHYs support PCIe
>> only.
>>
>> All three PHYs must be programmed with an 8 bit receiver termination
>> value, which must be determined dynamically; only the combo PHY is
>> able to determine this value.  The combo PHY performs a special
>> calibration step at probe time to discover this, and that value is
>> used to program each PHY that operates in PCIe mode.  The combo
>> PHY must therefore be probed--first--if either of the PCIe-only
>> PHYs will be used.
>>
>> During normal operation, the USB or PCIe driver using the PHY must
>> ensure clocks and resets are set up properly.  However clocks are
>> enabled and resets are de-asserted temporarily by this driver to
>> perform the calibration step on the combo PHY.
>>
>> Tested-by: Junzhong Pan <panjunzhong@linux.spacemit.com>
>> Signed-off-by: Alex Elder <elder@riscstar.com>
>> ---
>>   drivers/phy/Kconfig                |  11 +
>>   drivers/phy/Makefile               |   1 +
>>   drivers/phy/phy-spacemit-k1-pcie.c | 639 +++++++++++++++++++++++++++++
>>   3 files changed, 651 insertions(+)
>>   create mode 100644 drivers/phy/phy-spacemit-k1-pcie.c

. . .

>> diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
>> index c670a8dac4680..20f0078e543c7 100644
>> --- a/drivers/phy/Makefile
>> +++ b/drivers/phy/Makefile

. . .

>> +static int k1_pcie_pll_lock(struct k1_pcie_phy *k1_phy, bool pcie)
>> +{
>> +	u32 val = pcie ? CFG_FORCE_RCV_RETRY : 0;
>> +	void __iomem *virt;
>> +
>> +	writel(val, k1_phy->regs + PCIE_RC_DONE_STATUS);
>> +
>> +	/*
>> +	 * Wait for indication the PHY PLL is locked.  Lanes for ports
>> +	 * B and C share a PLL, so it's enough to sample just lane 0.
>> +	 */
>> +	virt = k1_phy->regs + PCIE_PU_ADDR_CLK_CFG;	/* Lane 0 */
>> +
>> +	return readl_poll_timeout(virt, val, val & PLL_READY,
>> +				  POLL_DELAY, PLL_TIMEOUT);
>> +}
>> +
> 
> Can we use standard clk_ops and clk_mux to normalize this process?

I understand you're suggesting that we represent this as a clock.

Can you be more specific about how you suggest I do that?

For example, are you suggesting I create a separate clock driver
for this one PLL (in each PCIe register space)?

Or do you mean use clock structures and callbacks within this
driver to represent this?

I'm just not sure what you have in mind, and the two options I
mention seem a lot more complicated than this one function.

Thanks.

					-Alex

> Regards,
> Inochi

Re: [PATCH 1/6] dt-bindings: phy: spacemit: add SpacemiT PCIe/combo PHY

[Alex Elder]

On 8/13/25 9:52 PM, Yao Zi wrote:
> On Wed, Aug 13, 2025 at 01:46:55PM -0500, Alex Elder wrote:
>> Add the Device Tree binding for the PCIe/USB 3.0 combo PHY found in
>> the SpacemiT K1 SoC.  This is one of three PCIe PHYs, and is unusual
>> in that only the combo PHY can perform a calibration step needed to
>> determine settings used by the other two PCIe PHYs.
>>
>> Calibration must be done with the combo PHY in PCIe mode, and to allow
>> this to occur independent of the eventual use for the PHY (PCIe or USB)
>> some PCIe-related properties must be supplied: clocks; resets; and a
>> syscon phandle.
>>
>> Signed-off-by: Alex Elder <elder@riscstar.com>
>> ---
>>   .../bindings/phy/spacemit,k1-combo-phy.yaml   | 110 ++++++++++++++++++
>>   1 file changed, 110 insertions(+)
>>   create mode 100644 Documentation/devicetree/bindings/phy/spacemit,k1-combo-phy.yaml
>>
>> diff --git a/Documentation/devicetree/bindings/phy/spacemit,k1-combo-phy.yaml b/Documentation/devicetree/bindings/phy/spacemit,k1-combo-phy.yaml
>> new file mode 100644
>> index 0000000000000..ed78083a53231
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/phy/spacemit,k1-combo-phy.yaml
> 
> ...
> 
>> +  spacemit,syscon-pmu:
>> +    description:
>> +      PHandle that refers to the APMU system controller, whose
>> +      regmap is used in setting the mode
>> +    $ref: /schemas/types.yaml#/definitions/phandle
> 
> Clock controllers and ethernet controllers all use spacemit,apmu to
> refer the APMU system controller. Do you think it's better to keep them
> aligned?

I do think it's better to keep them aligned.

And I appreciate your noticing this.  I don't see anything
that's accepted upstream that defines properties like this,
but I now see this:
  
https://lore.kernel.org/lkml/20250812-net-k1-emac-v5-2-dd17c4905f49@iscas.ac.cn/

I did a quick scan for what others do when a property's
value is a phandle, and other than just "syscon" it seems
that word is omitted.

So unless someone else suggests otherwise, I'll use
"spacemit,apmu" for this property in my next version.

> ...
> 
>> +
>> +additionalProperties: false
>> +
>> +examples:
>> +  - |
>> +    #include <dt-bindings/clock/spacemit,k1-syscon.h>
>> +    combo_phy: phy@c0b10000 {
> 
> This label is unnecessary.

OK.  I used it when testing USB but we can add the label
back when that driver gets reviewed.

>> +        compatible = "spacemit,k1-combo-phy";
>> +        reg = <0xc0b10000 0x1000>;
>> +        clocks = <&syscon_apmu CLK_PCIE0_DBI>,
>> +                 <&syscon_apmu CLK_PCIE0_MASTER>,
>> +                 <&syscon_apmu CLK_PCIE0_SLAVE>;
>> +        clock-names = "dbi",
>> +                      "mstr",
>> +                      "slv";
>> +        resets = <&syscon_apmu RESET_PCIE0_DBI>,
>> +                 <&syscon_apmu RESET_PCIE0_MASTER>,
>> +                 <&syscon_apmu RESET_PCIE0_SLAVE>,
>> +                 <&syscon_apmu RESET_PCIE0_GLOBAL>;
>> +        reset-names = "dbi",
>> +                      "mstr",
>> +                      "slv",
>> +                      "global";
>> +        spacemit,syscon-pmu = <&syscon_apmu>;
>> +        #phy-cells = <1>;
>> +        status = "disabled";
>> +    };
> 
> Best regards,
> Yao Zi

Thanks a lot.

					-Alex

Re: [PATCH 1/6] dt-bindings: phy: spacemit: add SpacemiT PCIe/combo PHY

[Rob Herring]

On Wed, Aug 13, 2025 at 01:46:55PM -0500, Alex Elder wrote:
> Add the Device Tree binding for the PCIe/USB 3.0 combo PHY found in
> the SpacemiT K1 SoC.  This is one of three PCIe PHYs, and is unusual
> in that only the combo PHY can perform a calibration step needed to
> determine settings used by the other two PCIe PHYs.
> 
> Calibration must be done with the combo PHY in PCIe mode, and to allow
> this to occur independent of the eventual use for the PHY (PCIe or USB)
> some PCIe-related properties must be supplied: clocks; resets; and a
> syscon phandle.
> 
> Signed-off-by: Alex Elder <elder@riscstar.com>
> ---
>  .../bindings/phy/spacemit,k1-combo-phy.yaml   | 110 ++++++++++++++++++
>  1 file changed, 110 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/phy/spacemit,k1-combo-phy.yaml
> 
> diff --git a/Documentation/devicetree/bindings/phy/spacemit,k1-combo-phy.yaml b/Documentation/devicetree/bindings/phy/spacemit,k1-combo-phy.yaml
> new file mode 100644
> index 0000000000000..ed78083a53231
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/phy/spacemit,k1-combo-phy.yaml
> @@ -0,0 +1,110 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/phy/spacemit,k1-combo-phy.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: SpacemiT K1 PCIe/USB3 Combo PHY
> +
> +maintainers:
> +  - Alex Elder <elder@riscstar.com>
> +
> +description:

You need a '>' or the paragraphs formatting will not be maintained 
(should we ever render docs from this).

> +  Of the three PHYs on the SpacemiT K1 SoC capable of being used for
> +  PCIe, one is a combo PHY that can also be configured for use by a
> +  USB 3 controller.  Using PCIe or USB 3 is a board design decision.
> +
> +  The combo PHY is also the only PCIe PHY that is able to determine
> +  PCIe calibration values to use, and this must be determined before
> +  the other two PCIe PHYs can be used.  This calibration must be
> +  performed with the combo PHY in PCIe mode, and is this is done
> +  when the combo PHY is probed.
> +
> +  During normal operation, the PCIe or USB port driver is responsible
> +  for ensuring all clocks needed by a PHY are enabled, and all resets
> +  affecting the PHY are deasserted.  However, for the combo PHY to
> +  perform calibration independent of whether it's later used for
> +  PCIe or USB, all PCIe mode clocks and resets must be defined.
> +
> +properties:
> +  compatible:
> +    const: spacemit,k1-combo-phy
> +
> +  reg:
> +    items:
> +      - description: PHY control registers
> +
> +  clocks:
> +    items:
> +      - description: DWC PCIe Data Bus Interface (DBI) clock
> +      - description: DWC PCIe application AXI-bus Master interface clock
> +      - description: DWC PCIe application AXI-bus Slave interface clock.

End with a period or don't. Just be consistent.

You need DWC PCIe clocks for your PHY? A ref clock would make sense, but 
these? I've never seen a PHY with a AXI master interface.

> +
> +  clock-names:
> +    items:
> +      - const: dbi
> +      - const: mstr
> +      - const: slv
> +
> +  resets:
> +    items:
> +      - description: DWC PCIe Data Bus Interface (DBI) reset
> +      - description: DWC PCIe application AXI-bus Master interface reset
> +      - description: DWC PCIe application AXI-bus Slave interface reset.

Same here (on both points).

> +      - description: Global reset; must be deasserted for PHY to function
> +
> +  reset-names:
> +    items:
> +      - const: dbi
> +      - const: mstr
> +      - const: slv
> +      - const: global
> +
> +  spacemit,syscon-pmu:
> +    description:
> +      PHandle that refers to the APMU system controller, whose
> +      regmap is used in setting the mode
> +    $ref: /schemas/types.yaml#/definitions/phandle
> +
> +  "#phy-cells":
> +    const: 1
> +    description:
> +      The argument value (PHY_TYPE_PCIE or PHY_TYPE_USB3) determines
> +      whether the PHY operates in PCIe or USB3 mode.
> +
> +required:
> +  - compatible
> +  - reg
> +  - clocks
> +  - clock-names
> +  - resets
> +  - reset-names
> +  - spacemit,syscon-pmu
> +  - "#phy-cells"
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/clock/spacemit,k1-syscon.h>
> +    combo_phy: phy@c0b10000 {

Drop unused labels.

> +        compatible = "spacemit,k1-combo-phy";
> +        reg = <0xc0b10000 0x1000>;
> +        clocks = <&syscon_apmu CLK_PCIE0_DBI>,
> +                 <&syscon_apmu CLK_PCIE0_MASTER>,
> +                 <&syscon_apmu CLK_PCIE0_SLAVE>;
> +        clock-names = "dbi",
> +                      "mstr",
> +                      "slv";
> +        resets = <&syscon_apmu RESET_PCIE0_DBI>,
> +                 <&syscon_apmu RESET_PCIE0_MASTER>,
> +                 <&syscon_apmu RESET_PCIE0_SLAVE>,
> +                 <&syscon_apmu RESET_PCIE0_GLOBAL>;
> +        reset-names = "dbi",
> +                      "mstr",
> +                      "slv",
> +                      "global";
> +        spacemit,syscon-pmu = <&syscon_apmu>;
> +        #phy-cells = <1>;
> +        status = "disabled";
> +    };
> -- 
> 2.48.1
> 

Re: [PATCH 1/6] dt-bindings: phy: spacemit: add SpacemiT PCIe/combo PHY

[Alex Elder]

On 8/14/25 3:51 PM, Rob Herring wrote:
> On Wed, Aug 13, 2025 at 01:46:55PM -0500, Alex Elder wrote:
>> Add the Device Tree binding for the PCIe/USB 3.0 combo PHY found in
>> the SpacemiT K1 SoC.  This is one of three PCIe PHYs, and is unusual
>> in that only the combo PHY can perform a calibration step needed to
>> determine settings used by the other two PCIe PHYs.
>>
>> Calibration must be done with the combo PHY in PCIe mode, and to allow
>> this to occur independent of the eventual use for the PHY (PCIe or USB)
>> some PCIe-related properties must be supplied: clocks; resets; and a
>> syscon phandle.
>>
>> Signed-off-by: Alex Elder <elder@riscstar.com>
>> ---
>>   .../bindings/phy/spacemit,k1-combo-phy.yaml   | 110 ++++++++++++++++++
>>   1 file changed, 110 insertions(+)
>>   create mode 100644 Documentation/devicetree/bindings/phy/spacemit,k1-combo-phy.yaml
>>
>> diff --git a/Documentation/devicetree/bindings/phy/spacemit,k1-combo-phy.yaml b/Documentation/devicetree/bindings/phy/spacemit,k1-combo-phy.yaml
>> new file mode 100644
>> index 0000000000000..ed78083a53231
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/phy/spacemit,k1-combo-phy.yaml
>> @@ -0,0 +1,110 @@
>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
>> +%YAML 1.2
>> +---
>> +$id: http://devicetree.org/schemas/phy/spacemit,k1-combo-phy.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: SpacemiT K1 PCIe/USB3 Combo PHY
>> +
>> +maintainers:
>> +  - Alex Elder <elder@riscstar.com>
>> +
>> +description:
> 
> You need a '>' or the paragraphs formatting will not be maintained
> (should we ever render docs from this).

OK.

>> +  Of the three PHYs on the SpacemiT K1 SoC capable of being used for
>> +  PCIe, one is a combo PHY that can also be configured for use by a
>> +  USB 3 controller.  Using PCIe or USB 3 is a board design decision.
>> +
>> +  The combo PHY is also the only PCIe PHY that is able to determine
>> +  PCIe calibration values to use, and this must be determined before
>> +  the other two PCIe PHYs can be used.  This calibration must be
>> +  performed with the combo PHY in PCIe mode, and is this is done
>> +  when the combo PHY is probed.
>> +
>> +  During normal operation, the PCIe or USB port driver is responsible
>> +  for ensuring all clocks needed by a PHY are enabled, and all resets
>> +  affecting the PHY are deasserted.  However, for the combo PHY to
>> +  perform calibration independent of whether it's later used for
>> +  PCIe or USB, all PCIe mode clocks and resets must be defined.
>> +
>> +properties:
>> +  compatible:
>> +    const: spacemit,k1-combo-phy
>> +
>> +  reg:
>> +    items:
>> +      - description: PHY control registers
>> +
>> +  clocks:
>> +    items:
>> +      - description: DWC PCIe Data Bus Interface (DBI) clock
>> +      - description: DWC PCIe application AXI-bus Master interface clock
>> +      - description: DWC PCIe application AXI-bus Slave interface clock.
> 
> End with a period or don't. Just be consistent.

OK.

> You need DWC PCIe clocks for your PHY? A ref clock would make sense, but
> these? I've never seen a PHY with a AXI master interface.

*This* is what I was waiting for.  I explained it briefly in
the patch headers and elsewhere but I expected questions.

This is needed to support USB mode, while also supporting the other
PCIe interfaces.

The SpacemiT IP requires its PCIe interfaces to have 4-bit RX and TX
receiver termination values be configured during initialization.  The
values to use must be determined dynamically by doing a calibration
step, then reading a (PCIe) register that contains the values to use.

Only the combo PHY is able to perform this calibration. and the
configuration values it determines must then be used to configure
the other two PCIe (only) PHYs.

This means that to calibrate, the combo PHY must be started (clocks
enabled, resets de-asserted) in PCIe mode.

If the combo PHY were going to be used for PCIe, this could be done
when it is initialized, because the PCIe driver would ensure the
clocks and resets were set up properly.

But if the combo PHY is going to be used for USB, the PCIe
calibration step would (otherwise) never be done, and that
means the other two PCIe interfaces could not be used.

So my solution is to move this calibration step into the PHY.
The combo PHY performs the calibration step when it is probed,
and to do that the driver needs to use its PCIe clocks and resets.
Once the calibration values are known, the clocks and resets
are essentially forgotten, and the PHY is available for use (by
either PCIe or USB 3).

The other two PCIe interfaces cannot probe (-EPROBE_DEFER) until
the calibration values are known, which means they might have to
wait until after the combo PHY has probed successfully.

I asked SpacemiT about this a lot, but their answer is that the
combo PHY is the only one that can determine these values, and
they must be determined each time the hardware is powered up.

I think this approach is less ugly than some alternatives.

Is this clear?  Can you think of a different way of handling it?

>> +
>> +  clock-names:
>> +    items:
>> +      - const: dbi
>> +      - const: mstr
>> +      - const: slv
>> +
>> +  resets:
>> +    items:
>> +      - description: DWC PCIe Data Bus Interface (DBI) reset
>> +      - description: DWC PCIe application AXI-bus Master interface reset
>> +      - description: DWC PCIe application AXI-bus Slave interface reset.
> 
> Same here (on both points).

I will remove the period on the third one.

> 
>> +      - description: Global reset; must be deasserted for PHY to function
>> +
>> +  reset-names:
>> +    items:
>> +      - const: dbi
>> +      - const: mstr
>> +      - const: slv
>> +      - const: global
>> +
>> +  spacemit,syscon-pmu:
>> +    description:
>> +      PHandle that refers to the APMU system controller, whose
>> +      regmap is used in setting the mode
>> +    $ref: /schemas/types.yaml#/definitions/phandle
>> +
>> +  "#phy-cells":
>> +    const: 1
>> +    description:
>> +      The argument value (PHY_TYPE_PCIE or PHY_TYPE_USB3) determines
>> +      whether the PHY operates in PCIe or USB3 mode.
>> +
>> +required:
>> +  - compatible
>> +  - reg
>> +  - clocks
>> +  - clock-names
>> +  - resets
>> +  - reset-names
>> +  - spacemit,syscon-pmu
>> +  - "#phy-cells"
>> +
>> +additionalProperties: false
>> +
>> +examples:
>> +  - |
>> +    #include <dt-bindings/clock/spacemit,k1-syscon.h>
>> +    combo_phy: phy@c0b10000 {
> 
> Drop unused labels.

OK.

>> +        compatible = "spacemit,k1-combo-phy";
>> +        reg = <0xc0b10000 0x1000>;
>> +        clocks = <&syscon_apmu CLK_PCIE0_DBI>,
>> +                 <&syscon_apmu CLK_PCIE0_MASTER>,
>> +                 <&syscon_apmu CLK_PCIE0_SLAVE>;
>> +        clock-names = "dbi",
>> +                      "mstr",
>> +                      "slv";
>> +        resets = <&syscon_apmu RESET_PCIE0_DBI>,
>> +                 <&syscon_apmu RESET_PCIE0_MASTER>,
>> +                 <&syscon_apmu RESET_PCIE0_SLAVE>,
>> +                 <&syscon_apmu RESET_PCIE0_GLOBAL>;
>> +        reset-names = "dbi",
>> +                      "mstr",
>> +                      "slv",
>> +                      "global";
>> +        spacemit,syscon-pmu = <&syscon_apmu>;
>> +        #phy-cells = <1>;
>> +        status = "disabled";

Krzysztof also pointed out that I can't disable it so I'll drop
the above line as well.

Thanks for the review.

					-Alex

>> +    };
>> -- 
>> 2.48.1
>>

Re: [PATCH 4/6] phy: spacemit: introduce PCIe/combo PHY

[Inochi Amaoto]

On Thu, Aug 14, 2025 at 07:15:43AM -0500, Alex Elder wrote:
> On 8/13/25 6:42 PM, Inochi Amaoto wrote:
> > On Wed, Aug 13, 2025 at 01:46:58PM -0500, Alex Elder wrote:
> > > Introduce a driver that supports three PHYs found on the SpacemiT
> > > K1 SoC.  The first PHY is a combo PHY that can be configured for
> > > use for either USB 3 or PCIe.  The other two PHYs support PCIe
> > > only.
> > > 
> > > All three PHYs must be programmed with an 8 bit receiver termination
> > > value, which must be determined dynamically; only the combo PHY is
> > > able to determine this value.  The combo PHY performs a special
> > > calibration step at probe time to discover this, and that value is
> > > used to program each PHY that operates in PCIe mode.  The combo
> > > PHY must therefore be probed--first--if either of the PCIe-only
> > > PHYs will be used.
> > > 
> > > During normal operation, the USB or PCIe driver using the PHY must
> > > ensure clocks and resets are set up properly.  However clocks are
> > > enabled and resets are de-asserted temporarily by this driver to
> > > perform the calibration step on the combo PHY.
> > > 
> > > Tested-by: Junzhong Pan <panjunzhong@linux.spacemit.com>
> > > Signed-off-by: Alex Elder <elder@riscstar.com>
> > > ---
> > >   drivers/phy/Kconfig                |  11 +
> > >   drivers/phy/Makefile               |   1 +
> > >   drivers/phy/phy-spacemit-k1-pcie.c | 639 +++++++++++++++++++++++++++++
> > >   3 files changed, 651 insertions(+)
> > >   create mode 100644 drivers/phy/phy-spacemit-k1-pcie.c
> 
> . . .
> 
> > > diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
> > > index c670a8dac4680..20f0078e543c7 100644
> > > --- a/drivers/phy/Makefile
> > > +++ b/drivers/phy/Makefile
> 
> . . .
> 
> > > +static int k1_pcie_pll_lock(struct k1_pcie_phy *k1_phy, bool pcie)
> > > +{
> > > +	u32 val = pcie ? CFG_FORCE_RCV_RETRY : 0;
> > > +	void __iomem *virt;
> > > +
> > > +	writel(val, k1_phy->regs + PCIE_RC_DONE_STATUS);
> > > +
> > > +	/*
> > > +	 * Wait for indication the PHY PLL is locked.  Lanes for ports
> > > +	 * B and C share a PLL, so it's enough to sample just lane 0.
> > > +	 */
> > > +	virt = k1_phy->regs + PCIE_PU_ADDR_CLK_CFG;	/* Lane 0 */
> > > +
> > > +	return readl_poll_timeout(virt, val, val & PLL_READY,
> > > +				  POLL_DELAY, PLL_TIMEOUT);
> > > +}
> > > +
> > 
> > Can we use standard clk_ops and clk_mux to normalize this process?
> 
> I understand you're suggesting that we represent this as a clock.
> 
> Can you be more specific about how you suggest I do that?
> 
> For example, are you suggesting I create a separate clock driver
> for this one PLL (in each PCIe register space)?
> 
> Or do you mean use clock structures and callbacks within this
> driver to represent this?
> 

I think using clock structures and registering them is just fine, 
there are many phy drivers already do this.

> I'm just not sure what you have in mind, and the two options I
> mention seem a lot more complicated than this one function.
> 

Yes, it is more complex than just adding one function, but it 
make the code clean and easy to understand as the clock looks
complex. Also, register this clock allow us to know the state
of internal clock by looking clk_summary.

Regards,
Inochi

Re: [PATCH 4/6] phy: spacemit: introduce PCIe/combo PHY

[Yixun Lan]

Hi Alex,

On 07:15 Thu 14 Aug     , Alex Elder wrote:
> On 8/13/25 6:42 PM, Inochi Amaoto wrote:
> > On Wed, Aug 13, 2025 at 01:46:58PM -0500, Alex Elder wrote:
> >> Introduce a driver that supports three PHYs found on the SpacemiT
> >> K1 SoC.  The first PHY is a combo PHY that can be configured for
> >> use for either USB 3 or PCIe.  The other two PHYs support PCIe
> >> only.
> >>
> >> All three PHYs must be programmed with an 8 bit receiver termination
> >> value, which must be determined dynamically; only the combo PHY is
> >> able to determine this value.  The combo PHY performs a special
> >> calibration step at probe time to discover this, and that value is
> >> used to program each PHY that operates in PCIe mode.  The combo
> >> PHY must therefore be probed--first--if either of the PCIe-only
> >> PHYs will be used.
> >>
> >> During normal operation, the USB or PCIe driver using the PHY must
> >> ensure clocks and resets are set up properly.  However clocks are
> >> enabled and resets are de-asserted temporarily by this driver to
> >> perform the calibration step on the combo PHY.
> >>
> >> Tested-by: Junzhong Pan <panjunzhong@linux.spacemit.com>
> >> Signed-off-by: Alex Elder <elder@riscstar.com>
> >> ---
> >>   drivers/phy/Kconfig                |  11 +
> >>   drivers/phy/Makefile               |   1 +
> >>   drivers/phy/phy-spacemit-k1-pcie.c | 639 +++++++++++++++++++++++++++++
> >>   3 files changed, 651 insertions(+)
> >>   create mode 100644 drivers/phy/phy-spacemit-k1-pcie.c
> 
> . . .
> 
> >> diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
> >> index c670a8dac4680..20f0078e543c7 100644
> >> --- a/drivers/phy/Makefile
> >> +++ b/drivers/phy/Makefile
> 
> . . .
> 
> >> +static int k1_pcie_pll_lock(struct k1_pcie_phy *k1_phy, bool pcie)
> >> +{
> >> +	u32 val = pcie ? CFG_FORCE_RCV_RETRY : 0;
> >> +	void __iomem *virt;
> >> +
> >> +	writel(val, k1_phy->regs + PCIE_RC_DONE_STATUS);
> >> +
> >> +	/*
> >> +	 * Wait for indication the PHY PLL is locked.  Lanes for ports
> >> +	 * B and C share a PLL, so it's enough to sample just lane 0.
> >> +	 */
> >> +	virt = k1_phy->regs + PCIE_PU_ADDR_CLK_CFG;	/* Lane 0 */
> >> +
> >> +	return readl_poll_timeout(virt, val, val & PLL_READY,
> >> +				  POLL_DELAY, PLL_TIMEOUT);
> >> +}
> >> +
> > 
> > Can we use standard clk_ops and clk_mux to normalize this process?
> 
> I understand you're suggesting that we represent this as a clock.
> 
> Can you be more specific about how you suggest I do that?
> 
> For example, are you suggesting I create a separate clock driver
> for this one PLL (in each PCIe register space)?
> 
> Or do you mean use clock structures and callbacks within this
> driver to represent this?
> 
> I'm just not sure what you have in mind, and the two options I
> mention seem a lot more complicated than this one function.
> 
> Thanks.
you can take a look at k1's i2c patch that Troy just sent which has similar case

https://lore.kernel.org/all/20250814-k1-i2c-ilcr-v3-1-317723e74bcd@linux.spacemit.com/

> 
> 					-Alex
> 
> > Regards,
> > Inochi
> 

-- 
Yixun Lan (dlan)