[PATCH v5 0/8] Add support for the LAN966x PCI device using a DT overlay

[PATCH v5 0/8] Add support for the LAN966x PCI device using a DT overlay

[Herve Codina]

Hi,

This series adds support for the LAN966x chip when used as a PCI
device.

For reference, the LAN996x chip is a System-on-chip that integrates an
Ethernet switch and a number of other traditional hardware blocks such
as a GPIO controller, I2C controllers, SPI controllers, etc. The
LAN996x can be used in two different modes:

- With Linux running on its Linux built-in ARM cores.
  This mode is already supported by the upstream Linux kernel, with the
  LAN996x described as a standard ARM Device Tree in
  arch/arm/boot/dts/microchip/lan966x.dtsi. Thanks to this support,
  all hardware blocks in the LAN996x already have drivers in the
  upstream Linux kernel.

- As a PCI device, thanks to its built-in PCI endpoint controller.
  In this case, the LAN996x ARM cores are not used, but all peripherals
  of the LAN996x can be accessed by the PCI host using memory-mapped
  I/O through the PCI BARs.

This series aims at supporting this second use-case. As all peripherals
of the LAN996x already have drivers in the Linux kernel, our goal is to
re-use them as-is to support this second use-case.

Therefore, this patch series introduces a PCI driver that binds on the
LAN996x PCI VID/PID, and when probed, instantiates all devices that are
accessible through the PCI BAR. As the list and characteristics of such
devices are non-discoverable, this PCI driver loads a Device Tree
overlay that allows to teach the kernel about which devices are
available, and allows to probe the relevant drivers in kernel, re-using
all existing drivers with no change.

This patch series for now adds a Device Tree overlay that describes an
initial subset of the devices available over PCI in the LAN996x, and
follow-up patch series will add support for more once this initial
support has landed.

In order to add this PCI driver, a number of preparation changes are
needed:
 - Patches 1, 2 introduce the LAN996x PCI driver itself, together with
   its DT overlay and the related MAINTAINTER entry.

 - Patches 3 to 8 allow the reset driver used for the LAN996x to be
   built as a module. Indeed, in the case where Linux runs on the ARM
   cores, it is common to have the reset driver built-in. However, when
   the LAN996x is used as a PCI device, it makes sense that all its
   drivers can be loaded as modules.

Compare to the previous iteration:
  https://lore.kernel.org/lkml/20240805101725.93947-1-herve.codina@bootlin.com/
this v5 series mainly:
  - Do improvements in LAN966x PCI driver
  - Add some 'Reviewed-by'

Best regards,
Hervé

Changes v4 -> v4
  - Patch 1
    Add missing include files and keep pci_ids.h.
    Remove IRQ_RETVAL() usage.
    Use __free().
    Remove the pdev->irq check.
    Avoid local variables in devm_pci_dev_remove_intr_ctrl() and
    lan966x_pci_load_overlay().
    Use dev_err_probe().
    Sort header includes in alphabetical order in dtbs file.

  - Patch 3
    Fix a typo in commit log.
    Simplify modification done in device_node_get_syscon().
    Use devm_add_action_or_reset().

  - Patches 4, 5, 6 and 8
    Add 'Reviewed-by: Steen Hegelund <Steen.Hegelund@microchip.com>'

Changes v3 -> v4
  - Patch 1 and 2 (v3 patch 6 and 7)
    Move the driver from drivers/mfd to drivers/misc.

  - Patch 4 and 5 (v3 patch 2)
    Rework reset driver dependencies and module building support.
    Split v3 patch into two distinct patches:
      - patch 4, as suggested by Geert, add a dependency on the
        LAN966x PCI device
      - patch 5, allows to build the reset controller driver as a module

  - Other patches
    Except reordering, no changes

Changes v2 -> v3
  - Patches 1 and 5
    No changes

  - Patch 6 (v2 patch 18)
    Add a blank line in the commit log to split paragraphs
    Remove unneeded header file inclusion
    Use IRQ_RETVAL()
    Remove blank line
    Use dev_of_node()
    Use pci_{set,get}_drvdata()
    Remove unneeded pci_clear_master() call
    Move { 0, } to { }
    Remove the unneeded pci_dev member from the lan966x_pci structure
    Use PCI_VENDOR_ID_EFAR instead of the hardcoded 0x1055 PCI Vendor ID
    Add a comment related to the of_node check.

  - Patch 7 (v2 patch 19)
    No changes

  Patches removed in v3
    - Patches 6 and 7
      Extracted and sent separately
      https://lore.kernel.org/lkml/20240620120126.412323-1-herve.codina@bootlin.com/

    - Patches 9
      Already applied

    - Patches 8, 10 to 12
      Extracted, reworked and sent separately
      https://lore.kernel.org/lkml/20240614173232.1184015-1-herve.codina@bootlin.com/

    - Patches 13 to 14
      Already applied

Changes v1 -> v2
  - Patch 1
    Fix a typo in syscon.h (s/intline/inline/)

  - Patches 2..5
    No changes

  - Patch 6
    Improve the reset property description

  - Patch 7
    Fix a wrong reverse x-mass tree declaration

  - Patch 8 removed (sent alone to net)
    https://lore.kernel.org/lkml/20240513111853.58668-1-herve.codina@bootlin.com/

  - Patch 8 (v1 patch 9)
    Add 'Reviewed-by: Rob Herring (Arm) <robh@kernel.org>'

  - Patch 9 (v1 patch 10)
    Rephrase and ident parameters descriptions

  - Patch 10 (v1 patch 11)
    No changes

  - Patch 11 (v1 patch 12)
    Fix a missing ret value assignment before a goto in .probe()
    Limit lines to 80 columns
    Use indices in register offset definitions

  - Patch 13 and 14 (new patches in v2)
    Add new test cases for existing of_changeset_add_prop_*()

  - Patch 15 (v1 patch 14)
    No changes

  - Patch 16 (new patches in v2)
    Add tests for of_changeset_add_prop_bool()

  - Patch 17 (v1 patch 15)
    Update commit subject
    Rewrap a paragraph in commit log

  - Patch 18 (v1 patch 16)
    Use PCI_IRQ_INTX instead of PCI_IRQ_LEGACY

  - Patch 19 (v1 patch 17)
    No changes

Clément Léger (5):
  mfd: syscon: Add reference counting and device managed support
  reset: mchp: sparx5: Allow building as a module
  reset: mchp: sparx5: Release syscon when not use anymore
  reset: core: add get_device()/put_device on rcdev
  reset: mchp: sparx5: set the dev member of the reset controller

Herve Codina (3):
  misc: Add support for LAN966x PCI device
  MAINTAINERS: Add the Microchip LAN966x PCI driver entry
  reset: mchp: sparx5: Add MCHP_LAN966X_PCI dependency

 MAINTAINERS                            |   6 +
 drivers/mfd/syscon.c                   | 138 ++++++++++++++--
 drivers/misc/Kconfig                   |  24 +++
 drivers/misc/Makefile                  |   3 +
 drivers/misc/lan966x_pci.c             | 215 +++++++++++++++++++++++++
 drivers/misc/lan966x_pci.dtso          | 167 +++++++++++++++++++
 drivers/pci/quirks.c                   |   1 +
 drivers/reset/Kconfig                  |   4 +-
 drivers/reset/core.c                   |   2 +
 drivers/reset/reset-microchip-sparx5.c |  11 +-
 include/linux/mfd/syscon.h             |  16 ++
 11 files changed, 569 insertions(+), 18 deletions(-)
 create mode 100644 drivers/misc/lan966x_pci.c
 create mode 100644 drivers/misc/lan966x_pci.dtso

-- 
2.45.0

[PATCH v5 1/8] misc: Add support for LAN966x PCI device

[Herve Codina]

Add a PCI driver that handles the LAN966x PCI device using a device-tree
overlay. This overlay is applied to the PCI device DT node and allows to
describe components that are present in the device.

The memory from the device-tree is remapped to the BAR memory thanks to
"ranges" properties computed at runtime by the PCI core during the PCI
enumeration.

The PCI device itself acts as an interrupt controller and is used as the
parent of the internal LAN966x interrupt controller to route the
interrupts to the assigned PCI INTx interrupt.

Signed-off-by: Herve Codina <herve.codina@bootlin.com>
---
 drivers/misc/Kconfig          |  24 ++++
 drivers/misc/Makefile         |   3 +
 drivers/misc/lan966x_pci.c    | 215 ++++++++++++++++++++++++++++++++++
 drivers/misc/lan966x_pci.dtso | 167 ++++++++++++++++++++++++++
 drivers/pci/quirks.c          |   1 +
 5 files changed, 410 insertions(+)
 create mode 100644 drivers/misc/lan966x_pci.c
 create mode 100644 drivers/misc/lan966x_pci.dtso

diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index 41c3d2821a78..6cd105a44abb 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -600,6 +600,30 @@ config MARVELL_CN10K_DPI
 	  To compile this driver as a module, choose M here: the module
 	  will be called mrvl_cn10k_dpi.
 
+config MCHP_LAN966X_PCI
+	tristate "Microchip LAN966x PCIe Support"
+	depends on PCI
+	select OF
+	select OF_OVERLAY
+	select IRQ_DOMAIN
+	help
+	  This enables the support for the LAN966x PCIe device.
+	  This is used to drive the LAN966x PCIe device from the host system
+	  to which it is connected.
+
+	  This driver uses an overlay to load other drivers to support for
+	  LAN966x internal components.
+	  Even if this driver does not depend on these other drivers, in order
+	  to have a fully functional board, the following drivers are needed:
+	    - fixed-clock (COMMON_CLK)
+	    - lan966x-oic (LAN966X_OIC)
+	    - lan966x-cpu-syscon (MFD_SYSCON)
+	    - lan966x-switch-reset (RESET_MCHP_SPARX5)
+	    - lan966x-pinctrl (PINCTRL_OCELOT)
+	    - lan966x-serdes (PHY_LAN966X_SERDES)
+	    - lan966x-miim (MDIO_MSCC_MIIM)
+	    - lan966x-switch (LAN966X_SWITCH)
+
 source "drivers/misc/c2port/Kconfig"
 source "drivers/misc/eeprom/Kconfig"
 source "drivers/misc/cb710/Kconfig"
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index c2f990862d2b..a1bdbf404f13 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -70,4 +70,7 @@ obj-$(CONFIG_TPS6594_ESM)	+= tps6594-esm.o
 obj-$(CONFIG_TPS6594_PFSM)	+= tps6594-pfsm.o
 obj-$(CONFIG_NSM)		+= nsm.o
 obj-$(CONFIG_MARVELL_CN10K_DPI)	+= mrvl_cn10k_dpi.o
+lan966x-pci-objs		:= lan966x_pci.o
+lan966x-pci-objs		+= lan966x_pci.dtbo.o
+obj-$(CONFIG_MCHP_LAN966X_PCI)	+= lan966x-pci.o
 obj-y				+= keba/
diff --git a/drivers/misc/lan966x_pci.c b/drivers/misc/lan966x_pci.c
new file mode 100644
index 000000000000..9c79b58137e5
--- /dev/null
+++ b/drivers/misc/lan966x_pci.c
@@ -0,0 +1,215 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Microchip LAN966x PCI driver
+ *
+ * Copyright (c) 2024 Microchip Technology Inc. and its subsidiaries.
+ *
+ * Authors:
+ *	Clément Léger <clement.leger@bootlin.com>
+ *	Hervé Codina <herve.codina@bootlin.com>
+ */
+
+#include <linux/device.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/pci.h>
+#include <linux/pci_ids.h>
+#include <linux/slab.h>
+
+/* Embedded dtbo symbols created by cmd_wrap_S_dtb in scripts/Makefile.lib */
+extern char __dtbo_lan966x_pci_begin[];
+extern char __dtbo_lan966x_pci_end[];
+
+struct pci_dev_intr_ctrl {
+	struct pci_dev *pci_dev;
+	struct irq_domain *irq_domain;
+	int irq;
+};
+
+static int pci_dev_irq_domain_map(struct irq_domain *d, unsigned int virq, irq_hw_number_t hw)
+{
+	irq_set_chip_and_handler(virq, &dummy_irq_chip, handle_simple_irq);
+	return 0;
+}
+
+static const struct irq_domain_ops pci_dev_irq_domain_ops = {
+	.map = pci_dev_irq_domain_map,
+	.xlate = irq_domain_xlate_onecell,
+};
+
+static irqreturn_t pci_dev_irq_handler(int irq, void *data)
+{
+	struct pci_dev_intr_ctrl *intr_ctrl = data;
+	int ret;
+
+	ret = generic_handle_domain_irq(intr_ctrl->irq_domain, 0);
+	return ret ? IRQ_NONE : IRQ_HANDLED;
+}
+
+static struct pci_dev_intr_ctrl *pci_dev_create_intr_ctrl(struct pci_dev *pdev)
+{
+	struct pci_dev_intr_ctrl *intr_ctrl __free(kfree) = NULL;
+	struct fwnode_handle *fwnode;
+	int ret;
+
+	fwnode = dev_fwnode(&pdev->dev);
+	if (!fwnode)
+		return ERR_PTR(-ENODEV);
+
+	intr_ctrl = kmalloc(sizeof(*intr_ctrl), GFP_KERNEL);
+	if (!intr_ctrl)
+		return ERR_PTR(-ENOMEM);
+
+	intr_ctrl->pci_dev = pdev;
+
+	intr_ctrl->irq_domain = irq_domain_create_linear(fwnode, 1, &pci_dev_irq_domain_ops,
+							 intr_ctrl);
+	if (!intr_ctrl->irq_domain) {
+		pci_err(pdev, "Failed to create irqdomain\n");
+		return ERR_PTR(-ENOMEM);
+	}
+
+	ret = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_INTX);
+	if (ret < 0) {
+		pci_err(pdev, "Unable alloc irq vector (%d)\n", ret);
+		goto err_remove_domain;
+	}
+	intr_ctrl->irq = pci_irq_vector(pdev, 0);
+	ret = request_irq(intr_ctrl->irq, pci_dev_irq_handler, IRQF_SHARED,
+			  pci_name(pdev), intr_ctrl);
+	if (ret) {
+		pci_err(pdev, "Unable to request irq %d (%d)\n", intr_ctrl->irq, ret);
+		goto err_free_irq_vector;
+	}
+
+	return_ptr(intr_ctrl);
+
+err_free_irq_vector:
+	pci_free_irq_vectors(pdev);
+err_remove_domain:
+	irq_domain_remove(intr_ctrl->irq_domain);
+	return ERR_PTR(ret);
+}
+
+static void pci_dev_remove_intr_ctrl(struct pci_dev_intr_ctrl *intr_ctrl)
+{
+	free_irq(intr_ctrl->irq, intr_ctrl);
+	pci_free_irq_vectors(intr_ctrl->pci_dev);
+	irq_dispose_mapping(irq_find_mapping(intr_ctrl->irq_domain, 0));
+	irq_domain_remove(intr_ctrl->irq_domain);
+	kfree(intr_ctrl);
+}
+
+static void devm_pci_dev_remove_intr_ctrl(void *intr_ctrl)
+{
+	pci_dev_remove_intr_ctrl(intr_ctrl);
+}
+
+static int devm_pci_dev_create_intr_ctrl(struct pci_dev *pdev)
+{
+	struct pci_dev_intr_ctrl *intr_ctrl;
+
+	intr_ctrl = pci_dev_create_intr_ctrl(pdev);
+	if (IS_ERR(intr_ctrl))
+		return PTR_ERR(intr_ctrl);
+
+	return devm_add_action_or_reset(&pdev->dev, devm_pci_dev_remove_intr_ctrl, intr_ctrl);
+}
+
+struct lan966x_pci {
+	struct device *dev;
+	int ovcs_id;
+};
+
+static int lan966x_pci_load_overlay(struct lan966x_pci *data)
+{
+	u32 dtbo_size = __dtbo_lan966x_pci_end - __dtbo_lan966x_pci_begin;
+	void *dtbo_start = __dtbo_lan966x_pci_begin;
+
+	return of_overlay_fdt_apply(dtbo_start, dtbo_size, &data->ovcs_id, dev_of_node(data->dev));
+}
+
+static void lan966x_pci_unload_overlay(struct lan966x_pci *data)
+{
+	of_overlay_remove(&data->ovcs_id);
+}
+
+static int lan966x_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
+{
+	struct device *dev = &pdev->dev;
+	struct lan966x_pci *data;
+	int ret;
+
+	/*
+	 * On ACPI system, fwnode can point to the ACPI node.
+	 * This driver needs an of_node to be used as the device-tree overlay
+	 * target. This of_node should be set by the PCI core if it succeeds in
+	 * creating it (CONFIG_PCI_DYNAMIC_OF_NODES feature).
+	 * Check here for the validity of this of_node.
+	 */
+	if (!dev_of_node(dev))
+		return dev_err_probe(dev, -EINVAL, "Missing of_node for device\n");
+
+	/* Need to be done before devm_pci_dev_create_intr_ctrl.
+	 * It allocates an IRQ and so pdev->irq is updated.
+	 */
+	ret = pcim_enable_device(pdev);
+	if (ret)
+		return ret;
+
+	ret = devm_pci_dev_create_intr_ctrl(pdev);
+	if (ret)
+		return ret;
+
+	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	pci_set_drvdata(pdev, data);
+	data->dev = dev;
+
+	ret = lan966x_pci_load_overlay(data);
+	if (ret)
+		return ret;
+
+	pci_set_master(pdev);
+
+	ret = of_platform_default_populate(dev_of_node(dev), NULL, dev);
+	if (ret)
+		goto err_unload_overlay;
+
+	return 0;
+
+err_unload_overlay:
+	lan966x_pci_unload_overlay(data);
+	return ret;
+}
+
+static void lan966x_pci_remove(struct pci_dev *pdev)
+{
+	struct lan966x_pci *data = pci_get_drvdata(pdev);
+
+	of_platform_depopulate(data->dev);
+
+	lan966x_pci_unload_overlay(data);
+}
+
+static struct pci_device_id lan966x_pci_ids[] = {
+	{ PCI_DEVICE(PCI_VENDOR_ID_EFAR, 0x9660) },
+	{ }
+};
+MODULE_DEVICE_TABLE(pci, lan966x_pci_ids);
+
+static struct pci_driver lan966x_pci_driver = {
+	.name = "mchp_lan966x_pci",
+	.id_table = lan966x_pci_ids,
+	.probe = lan966x_pci_probe,
+	.remove = lan966x_pci_remove,
+};
+module_pci_driver(lan966x_pci_driver);
+
+MODULE_AUTHOR("Herve Codina <herve.codina@bootlin.com>");
+MODULE_DESCRIPTION("Microchip LAN966x PCI driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/misc/lan966x_pci.dtso b/drivers/misc/lan966x_pci.dtso
new file mode 100644
index 000000000000..0e615208df11
--- /dev/null
+++ b/drivers/misc/lan966x_pci.dtso
@@ -0,0 +1,167 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2022 Microchip UNG
+ */
+
+#include <dt-bindings/clock/microchip,lan966x.h>
+#include <dt-bindings/gpio/gpio.h>
+#include <dt-bindings/interrupt-controller/irq.h>
+#include <dt-bindings/mfd/atmel-flexcom.h>
+#include <dt-bindings/phy/phy-lan966x-serdes.h>
+
+/dts-v1/;
+/plugin/;
+
+/ {
+	fragment@0 {
+		target-path="";
+		__overlay__ {
+			#address-cells = <3>;
+			#size-cells = <2>;
+
+			pci-ep-bus@0 {
+				compatible = "simple-bus";
+				#address-cells = <1>;
+				#size-cells = <1>;
+
+				/*
+				 * map @0xe2000000 (32MB) to BAR0 (CPU)
+				 * map @0xe0000000 (16MB) to BAR1 (AMBA)
+				 */
+				ranges = <0xe2000000 0x00 0x00 0x00 0x2000000
+				          0xe0000000 0x01 0x00 0x00 0x1000000>;
+
+				oic: oic@e00c0120 {
+					compatible = "microchip,lan966x-oic";
+					#interrupt-cells = <2>;
+					interrupt-controller;
+					interrupts = <0>; /* PCI INTx assigned interrupt */
+					reg = <0xe00c0120 0x190>;
+				};
+
+				cpu_clk: cpu_clk {
+					compatible = "fixed-clock";
+					#clock-cells = <0>;
+					clock-frequency = <600000000>;  // CPU clock = 600MHz
+				};
+
+				ddr_clk: ddr_clk {
+					compatible = "fixed-clock";
+					#clock-cells = <0>;
+					clock-frequency = <30000000>;  // Fabric clock = 30MHz
+				};
+
+				sys_clk: sys_clk {
+					compatible = "fixed-clock";
+					#clock-cells = <0>;
+					clock-frequency = <15625000>;  // System clock = 15.625MHz
+				};
+
+				cpu_ctrl: syscon@e00c0000 {
+					compatible = "microchip,lan966x-cpu-syscon", "syscon";
+					reg = <0xe00c0000 0xa8>;
+				};
+
+				reset: reset@e200400c {
+					compatible = "microchip,lan966x-switch-reset";
+					reg = <0xe200400c 0x4>;
+					reg-names = "gcb";
+					#reset-cells = <1>;
+					cpu-syscon = <&cpu_ctrl>;
+				};
+
+				gpio: pinctrl@e2004064 {
+					compatible = "microchip,lan966x-pinctrl";
+					reg = <0xe2004064 0xb4>,
+					      <0xe2010024 0x138>;
+					resets = <&reset 0>;
+					reset-names = "switch";
+					gpio-controller;
+					#gpio-cells = <2>;
+					gpio-ranges = <&gpio 0 0 78>;
+					interrupt-parent = <&oic>;
+					interrupt-controller;
+					interrupts = <17 IRQ_TYPE_LEVEL_HIGH>;
+					#interrupt-cells = <2>;
+
+					tod_pins: tod_pins {
+						pins = "GPIO_36";
+						function = "ptpsync_1";
+					};
+
+					fc0_a_pins: fcb4-i2c-pins {
+						/* RXD, TXD */
+						pins = "GPIO_9", "GPIO_10";
+						function = "fc0_a";
+					};
+
+				};
+
+				serdes: serdes@e202c000 {
+					compatible = "microchip,lan966x-serdes";
+					reg = <0xe202c000 0x9c>,
+					      <0xe2004010 0x4>;
+					#phy-cells = <2>;
+				};
+
+				mdio1: mdio@e200413c {
+					#address-cells = <1>;
+					#size-cells = <0>;
+					compatible = "microchip,lan966x-miim";
+					reg = <0xe200413c 0x24>,
+					      <0xe2010020 0x4>;
+
+					resets = <&reset 0>;
+					reset-names = "switch";
+
+					lan966x_phy0: ethernet-lan966x_phy@1 {
+						reg = <1>;
+					};
+
+					lan966x_phy1: ethernet-lan966x_phy@2 {
+						reg = <2>;
+					};
+				};
+
+				switch: switch@e0000000 {
+					compatible = "microchip,lan966x-switch";
+					reg = <0xe0000000 0x0100000>,
+					      <0xe2000000 0x0800000>;
+					reg-names = "cpu", "gcb";
+
+					interrupt-parent = <&oic>;
+					interrupts = <12 IRQ_TYPE_LEVEL_HIGH>,
+						     <9 IRQ_TYPE_LEVEL_HIGH>;
+					interrupt-names = "xtr", "ana";
+
+					resets = <&reset 0>;
+					reset-names = "switch";
+
+					pinctrl-names = "default";
+					pinctrl-0 = <&tod_pins>;
+
+					ethernet-ports {
+						#address-cells = <1>;
+						#size-cells = <0>;
+
+						port0: port@0 {
+							phy-handle = <&lan966x_phy0>;
+
+							reg = <0>;
+							phy-mode = "gmii";
+							phys = <&serdes 0 CU(0)>;
+						};
+
+						port1: port@1 {
+							phy-handle = <&lan966x_phy1>;
+
+							reg = <1>;
+							phy-mode = "gmii";
+							phys = <&serdes 1 CU(1)>;
+						};
+					};
+				};
+			};
+		};
+	};
+};
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index a2ce4e08edf5..bae2dd99017c 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -6245,6 +6245,7 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0xa76e, dpc_log_size);
 DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_XILINX, 0x5020, of_pci_make_dev_node);
 DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_XILINX, 0x5021, of_pci_make_dev_node);
 DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_REDHAT, 0x0005, of_pci_make_dev_node);
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_EFAR, 0x9660, of_pci_make_dev_node);
 
 /*
  * Devices known to require a longer delay before first config space access
-- 
2.45.0

[PATCH v5 2/8] MAINTAINERS: Add the Microchip LAN966x PCI driver entry

[Herve Codina]

After contributing the driver, add myself as the maintainer for the
Microchip LAN966x PCI driver.

Signed-off-by: Herve Codina <herve.codina@bootlin.com>
---
 MAINTAINERS | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 42decde38320..bec67cbb9224 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -14971,6 +14971,12 @@ S:	Maintained
 F:	Documentation/devicetree/bindings/interrupt-controller/microchip,lan966x-oic.yaml
 F:	drivers/irqchip/irq-lan966x-oic.c
 
+MICROCHIP LAN966X PCI DRIVER
+M:	Herve Codina <herve.codina@bootlin.com>
+S:	Maintained
+F:	drivers/misc/lan966x_pci.c
+F:	drivers/misc/lan966x_pci.dtso
+
 MICROCHIP LCDFB DRIVER
 M:	Nicolas Ferre <nicolas.ferre@microchip.com>
 L:	linux-fbdev@vger.kernel.org
-- 
2.45.0

[PATCH v5 3/8] mfd: syscon: Add reference counting and device managed support

[Herve Codina]

From: Clément Léger <clement.leger@bootlin.com>

Syscon releasing is not supported.
Without release function, unbinding a driver that uses syscon whether
explicitly or due to a module removal left the used syscon in a in-use
state.

For instance a syscon_node_to_regmap() call from a consumer retrieves a
syscon regmap instance. Internally, syscon_node_to_regmap() can create
syscon instance and add it to the existing syscon list. No API is
available to release this syscon instance, remove it from the list and
free it when it is not used anymore.

Introduce reference counting in syscon in order to keep track of syscon
usage using syscon_{get,put}() and add a device managed version of
syscon_regmap_lookup_by_phandle(), to automatically release the syscon
instance on the consumer removal.

Signed-off-by: Clément Léger <clement.leger@bootlin.com>
Signed-off-by: Herve Codina <herve.codina@bootlin.com>
---
 drivers/mfd/syscon.c       | 138 ++++++++++++++++++++++++++++++++++---
 include/linux/mfd/syscon.h |  16 +++++
 2 files changed, 144 insertions(+), 10 deletions(-)

diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c
index 33f1e07ab24d..a0f8737b8d63 100644
--- a/drivers/mfd/syscon.c
+++ b/drivers/mfd/syscon.c
@@ -34,6 +34,7 @@ struct syscon {
 	struct regmap *regmap;
 	struct reset_control *reset;
 	struct list_head list;
+	struct kref refcount;
 };
 
 static const struct regmap_config syscon_regmap_config = {
@@ -147,6 +148,8 @@ static struct syscon *of_syscon_register(struct device_node *np, bool check_res)
 
 	syscon->regmap = regmap;
 	syscon->np = np;
+	of_node_get(syscon->np);
+	kref_init(&syscon->refcount);
 
 	spin_lock(&syscon_list_slock);
 	list_add_tail(&syscon->list, &syscon_list);
@@ -168,7 +171,31 @@ static struct syscon *of_syscon_register(struct device_node *np, bool check_res)
 	return ERR_PTR(ret);
 }
 
-static struct regmap *device_node_get_regmap(struct device_node *np,
+static void syscon_free(struct kref *kref)
+{
+	struct syscon *syscon = container_of(kref, struct syscon, refcount);
+
+	spin_lock(&syscon_list_slock);
+	list_del(&syscon->list);
+	spin_unlock(&syscon_list_slock);
+
+	regmap_exit(syscon->regmap);
+	of_node_put(syscon->np);
+	kfree(syscon);
+}
+
+static struct syscon *syscon_get(struct syscon *syscon)
+{
+	kref_get(&syscon->refcount);
+	return syscon;
+}
+
+static void syscon_put(struct syscon *syscon)
+{
+	kref_put(&syscon->refcount, syscon_free);
+}
+
+static struct syscon *device_node_get_syscon(struct device_node *np,
 					     bool check_res)
 {
 	struct syscon *entry, *syscon = NULL;
@@ -183,9 +210,18 @@ static struct regmap *device_node_get_regmap(struct device_node *np,
 
 	spin_unlock(&syscon_list_slock);
 
-	if (!syscon)
-		syscon = of_syscon_register(np, check_res);
+	if (syscon)
+		return syscon_get(syscon);
+
+	return of_syscon_register(np, check_res);
+}
+
+static struct regmap *device_node_get_regmap(struct device_node *np,
+					     bool check_res)
+{
+	struct syscon *syscon;
 
+	syscon = device_node_get_syscon(np, check_res);
 	if (IS_ERR(syscon))
 		return ERR_CAST(syscon);
 
@@ -246,12 +282,23 @@ struct regmap *device_node_to_regmap(struct device_node *np)
 }
 EXPORT_SYMBOL_GPL(device_node_to_regmap);
 
-struct regmap *syscon_node_to_regmap(struct device_node *np)
+static struct syscon *syscon_node_to_syscon(struct device_node *np)
 {
 	if (!of_device_is_compatible(np, "syscon"))
 		return ERR_PTR(-EINVAL);
 
-	return device_node_get_regmap(np, true);
+	return device_node_get_syscon(np, true);
+}
+
+struct regmap *syscon_node_to_regmap(struct device_node *np)
+{
+	struct syscon *syscon;
+
+	syscon = syscon_node_to_syscon(np);
+	if (IS_ERR(syscon))
+		return ERR_CAST(syscon);
+
+	return syscon->regmap;
 }
 EXPORT_SYMBOL_GPL(syscon_node_to_regmap);
 
@@ -271,11 +318,11 @@ struct regmap *syscon_regmap_lookup_by_compatible(const char *s)
 }
 EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_compatible);
 
-struct regmap *syscon_regmap_lookup_by_phandle(struct device_node *np,
-					const char *property)
+static struct syscon *syscon_lookup_by_phandle(struct device_node *np,
+					       const char *property)
 {
 	struct device_node *syscon_np;
-	struct regmap *regmap;
+	struct syscon *syscon;
 
 	if (property)
 		syscon_np = of_parse_phandle(np, property, 0);
@@ -285,12 +332,24 @@ struct regmap *syscon_regmap_lookup_by_phandle(struct device_node *np,
 	if (!syscon_np)
 		return ERR_PTR(-ENODEV);
 
-	regmap = syscon_node_to_regmap(syscon_np);
+	syscon = syscon_node_to_syscon(syscon_np);
 
 	if (property)
 		of_node_put(syscon_np);
 
-	return regmap;
+	return syscon;
+}
+
+struct regmap *syscon_regmap_lookup_by_phandle(struct device_node *np,
+					       const char *property)
+{
+	struct syscon *syscon;
+
+	syscon = syscon_lookup_by_phandle(np, property);
+	if (IS_ERR(syscon))
+		return ERR_CAST(syscon);
+
+	return syscon->regmap;
 }
 EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_phandle);
 
@@ -341,6 +400,65 @@ struct regmap *syscon_regmap_lookup_by_phandle_optional(struct device_node *np,
 }
 EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_phandle_optional);
 
+static struct syscon *syscon_from_regmap(struct regmap *regmap)
+{
+	struct syscon *entry, *syscon = NULL;
+
+	spin_lock(&syscon_list_slock);
+
+	list_for_each_entry(entry, &syscon_list, list)
+		if (entry->regmap == regmap) {
+			syscon = entry;
+			break;
+		}
+
+	spin_unlock(&syscon_list_slock);
+
+	return syscon;
+}
+
+void syscon_put_regmap(struct regmap *regmap)
+{
+	struct syscon *syscon;
+
+	syscon = syscon_from_regmap(regmap);
+	if (!syscon)
+		return;
+
+	syscon_put(syscon);
+}
+EXPORT_SYMBOL_GPL(syscon_put_regmap);
+
+static void devm_syscon_release(void *syscon)
+{
+	syscon_put(syscon);
+}
+
+static struct regmap *__devm_syscon_get(struct device *dev,
+					struct syscon *syscon)
+{
+	int ret;
+
+	if (IS_ERR(syscon))
+		return ERR_CAST(syscon);
+
+	ret = devm_add_action_or_reset(dev, devm_syscon_release, syscon);
+	if (ret)
+		return ERR_PTR(ret);
+
+	return syscon->regmap;
+}
+
+struct regmap *devm_syscon_regmap_lookup_by_phandle(struct device *dev,
+						    struct device_node *np,
+						    const char *property)
+{
+	struct syscon *syscon = syscon_lookup_by_phandle(np, property);
+
+	return __devm_syscon_get(dev, syscon);
+}
+EXPORT_SYMBOL_GPL(devm_syscon_regmap_lookup_by_phandle);
+
 static int syscon_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
diff --git a/include/linux/mfd/syscon.h b/include/linux/mfd/syscon.h
index aad9c6b50463..a3025b4efb4a 100644
--- a/include/linux/mfd/syscon.h
+++ b/include/linux/mfd/syscon.h
@@ -15,6 +15,7 @@
 #include <linux/errno.h>
 
 struct device_node;
+struct device;
 
 #ifdef CONFIG_MFD_SYSCON
 struct regmap *device_node_to_regmap(struct device_node *np);
@@ -30,6 +31,10 @@ struct regmap *syscon_regmap_lookup_by_phandle_optional(struct device_node *np,
 							const char *property);
 int of_syscon_register_regmap(struct device_node *np,
 			      struct regmap *regmap);
+void syscon_put_regmap(struct regmap *regmap);
+struct regmap *devm_syscon_regmap_lookup_by_phandle(struct device *dev,
+						    struct device_node *np,
+						    const char *property);
 #else
 static inline struct regmap *device_node_to_regmap(struct device_node *np)
 {
@@ -73,6 +78,17 @@ static inline int of_syscon_register_regmap(struct device_node *np,
 					struct regmap *regmap)
 {
 	return -EOPNOTSUPP;
+
+static inline void syscon_put_regmap(struct regmap *regmap)
+{
+}
+
+static inline
+struct regmap *devm_syscon_regmap_lookup_by_phandle(struct device *dev,
+						    struct device_node *np,
+						    const char *property)
+{
+	return NULL;
 }
 
 #endif
-- 
2.45.0

[PATCH v5 4/8] reset: mchp: sparx5: Add MCHP_LAN966X_PCI dependency

[Herve Codina]

The sparx5 reset controller depends on the SPARX5 architecture or the
LAN966x SoC.

This reset controller can be used by the LAN966x PCI device and so it
needs to be available when the LAN966x PCI device is enabled.

Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Reviewed-by: Steen Hegelund <Steen.Hegelund@microchip.com>
---
 drivers/reset/Kconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
index 67bce340a87e..5b5a4d99616e 100644
--- a/drivers/reset/Kconfig
+++ b/drivers/reset/Kconfig
@@ -134,7 +134,7 @@ config RESET_LPC18XX
 
 config RESET_MCHP_SPARX5
 	bool "Microchip Sparx5 reset driver"
-	depends on ARCH_SPARX5 || SOC_LAN966 || COMPILE_TEST
+	depends on ARCH_SPARX5 || SOC_LAN966 || MCHP_LAN966X_PCI || COMPILE_TEST
 	default y if SPARX5_SWITCH
 	select MFD_SYSCON
 	help
-- 
2.45.0

[PATCH v5 5/8] reset: mchp: sparx5: Allow building as a module

[Herve Codina]

From: Clément Léger <clement.leger@bootlin.com>

This reset controller can be used by the LAN966x PCI device.

The LAN966x PCI device driver can be built as a module and this reset
controller driver has no reason to be a builtin driver in that case.

Signed-off-by: Clément Léger <clement.leger@bootlin.com>
Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Reviewed-by: Steen Hegelund <Steen.Hegelund@microchip.com>
---
 drivers/reset/Kconfig                  | 2 +-
 drivers/reset/reset-microchip-sparx5.c | 2 ++
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
index 5b5a4d99616e..88350aa8a51c 100644
--- a/drivers/reset/Kconfig
+++ b/drivers/reset/Kconfig
@@ -133,7 +133,7 @@ config RESET_LPC18XX
 	  This enables the reset controller driver for NXP LPC18xx/43xx SoCs.
 
 config RESET_MCHP_SPARX5
-	bool "Microchip Sparx5 reset driver"
+	tristate "Microchip Sparx5 reset driver"
 	depends on ARCH_SPARX5 || SOC_LAN966 || MCHP_LAN966X_PCI || COMPILE_TEST
 	default y if SPARX5_SWITCH
 	select MFD_SYSCON
diff --git a/drivers/reset/reset-microchip-sparx5.c b/drivers/reset/reset-microchip-sparx5.c
index 636e85c388b0..69915c7b4941 100644
--- a/drivers/reset/reset-microchip-sparx5.c
+++ b/drivers/reset/reset-microchip-sparx5.c
@@ -158,6 +158,7 @@ static const struct of_device_id mchp_sparx5_reset_of_match[] = {
 	},
 	{ }
 };
+MODULE_DEVICE_TABLE(of, mchp_sparx5_reset_of_match);
 
 static struct platform_driver mchp_sparx5_reset_driver = {
 	.probe = mchp_sparx5_reset_probe,
@@ -180,3 +181,4 @@ postcore_initcall(mchp_sparx5_reset_init);
 
 MODULE_DESCRIPTION("Microchip Sparx5 switch reset driver");
 MODULE_AUTHOR("Steen Hegelund <steen.hegelund@microchip.com>");
+MODULE_LICENSE("GPL");
-- 
2.45.0

[PATCH v5 6/8] reset: mchp: sparx5: Release syscon when not use anymore

[Herve Codina]

From: Clément Léger <clement.leger@bootlin.com>

The sparx5 reset controller does not release syscon when it is not used
anymore.

This reset controller is used by the LAN966x PCI device driver.
It can be removed from the system at runtime and needs to release its
consumed syscon on removal.

Use the newly introduced devm_syscon_regmap_lookup_by_phandle() in order
to get the syscon and automatically release it on removal.

Signed-off-by: Clément Léger <clement.leger@bootlin.com>
Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Reviewed-by: Steen Hegelund <Steen.Hegelund@microchip.com>
---
 drivers/reset/reset-microchip-sparx5.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/drivers/reset/reset-microchip-sparx5.c b/drivers/reset/reset-microchip-sparx5.c
index 69915c7b4941..c4fe65291a43 100644
--- a/drivers/reset/reset-microchip-sparx5.c
+++ b/drivers/reset/reset-microchip-sparx5.c
@@ -65,15 +65,11 @@ static const struct reset_control_ops sparx5_reset_ops = {
 static int mchp_sparx5_map_syscon(struct platform_device *pdev, char *name,
 				  struct regmap **target)
 {
-	struct device_node *syscon_np;
+	struct device *dev = &pdev->dev;
 	struct regmap *regmap;
 	int err;
 
-	syscon_np = of_parse_phandle(pdev->dev.of_node, name, 0);
-	if (!syscon_np)
-		return -ENODEV;
-	regmap = syscon_node_to_regmap(syscon_np);
-	of_node_put(syscon_np);
+	regmap = devm_syscon_regmap_lookup_by_phandle(dev, dev->of_node, name);
 	if (IS_ERR(regmap)) {
 		err = PTR_ERR(regmap);
 		dev_err(&pdev->dev, "No '%s' map: %d\n", name, err);
-- 
2.45.0

[PATCH v5 7/8] reset: core: add get_device()/put_device on rcdev

[Herve Codina]

From: Clément Léger <clement.leger@bootlin.com>

Since the rcdev structure is allocated by the reset controller drivers
themselves, they need to exists as long as there is a consumer. A call to
module_get() is already existing but that does not work when using
device-tree overlays. In order to guarantee that the underlying reset
controller device does not vanish while using it, add a get_device() call
when retrieving a reset control from a reset controller device and a
put_device() when releasing that control.

Signed-off-by: Clément Léger <clement.leger@bootlin.com>
Signed-off-by: Herve Codina <herve.codina@bootlin.com>
---
 drivers/reset/core.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/reset/core.c b/drivers/reset/core.c
index dba74e857be6..999c3c41cf21 100644
--- a/drivers/reset/core.c
+++ b/drivers/reset/core.c
@@ -812,6 +812,7 @@ __reset_control_get_internal(struct reset_controller_dev *rcdev,
 	kref_init(&rstc->refcnt);
 	rstc->acquired = acquired;
 	rstc->shared = shared;
+	get_device(rcdev->dev);
 
 	return rstc;
 }
@@ -826,6 +827,7 @@ static void __reset_control_release(struct kref *kref)
 	module_put(rstc->rcdev->owner);
 
 	list_del(&rstc->list);
+	put_device(rstc->rcdev->dev);
 	kfree(rstc);
 }
 
-- 
2.45.0

[PATCH v5 8/8] reset: mchp: sparx5: set the dev member of the reset controller

[Herve Codina]

From: Clément Léger <clement.leger@bootlin.com>

In order to guarantee the device will not be deleted by the reset
controller consumer, set the dev member of the reset controller.

Signed-off-by: Clément Léger <clement.leger@bootlin.com>
Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Reviewed-by: Steen Hegelund <Steen.Hegelund@microchip.com>
---
 drivers/reset/reset-microchip-sparx5.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/reset/reset-microchip-sparx5.c b/drivers/reset/reset-microchip-sparx5.c
index c4fe65291a43..1ef2aa1602e3 100644
--- a/drivers/reset/reset-microchip-sparx5.c
+++ b/drivers/reset/reset-microchip-sparx5.c
@@ -117,6 +117,7 @@ static int mchp_sparx5_reset_probe(struct platform_device *pdev)
 		return err;
 
 	ctx->rcdev.owner = THIS_MODULE;
+	ctx->rcdev.dev = &pdev->dev;
 	ctx->rcdev.nr_resets = 1;
 	ctx->rcdev.ops = &sparx5_reset_ops;
 	ctx->rcdev.of_node = dn;
-- 
2.45.0

Re: [PATCH v5 1/8] misc: Add support for LAN966x PCI device

[Greg Kroah-Hartman]

On Thu, Aug 08, 2024 at 05:46:50PM +0200, Herve Codina wrote:
> Add a PCI driver that handles the LAN966x PCI device using a device-tree
> overlay. This overlay is applied to the PCI device DT node and allows to
> describe components that are present in the device.
> 
> The memory from the device-tree is remapped to the BAR memory thanks to
> "ranges" properties computed at runtime by the PCI core during the PCI
> enumeration.
> 
> The PCI device itself acts as an interrupt controller and is used as the
> parent of the internal LAN966x interrupt controller to route the
> interrupts to the assigned PCI INTx interrupt.
> 
> Signed-off-by: Herve Codina <herve.codina@bootlin.com>

misc device is fine, even if it's not really one :)

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Re: [PATCH v5 7/8] reset: core: add get_device()/put_device on rcdev

[Philipp Zabel]

On Do, 2024-08-08 at 17:46 +0200, Herve Codina wrote:
> From: Clément Léger <clement.leger@bootlin.com>
> 
> Since the rcdev structure is allocated by the reset controller drivers
> themselves, they need to exists as long as there is a consumer. A call to
> module_get() is already existing but that does not work when using
> device-tree overlays. In order to guarantee that the underlying reset
> controller device does not vanish while using it, add a get_device() call
> when retrieving a reset control from a reset controller device and a
> put_device() when releasing that control.
> 
> Signed-off-by: Clément Léger <clement.leger@bootlin.com>
> Signed-off-by: Herve Codina <herve.codina@bootlin.com>
> ---
>  drivers/reset/core.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/reset/core.c b/drivers/reset/core.c
> index dba74e857be6..999c3c41cf21 100644
> --- a/drivers/reset/core.c
> +++ b/drivers/reset/core.c
> @@ -812,6 +812,7 @@ __reset_control_get_internal(struct reset_controller_dev *rcdev,
>  	kref_init(&rstc->refcnt);
>  	rstc->acquired = acquired;
>  	rstc->shared = shared;
> +	get_device(rcdev->dev);
>  
>  	return rstc;
>  }
> @@ -826,6 +827,7 @@ static void __reset_control_release(struct kref *kref)
>  	module_put(rstc->rcdev->owner);
>  
>  	list_del(&rstc->list);
> +	put_device(rstc->rcdev->dev);
>  	kfree(rstc);
>  }

Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>

regards
Philipp

Re: [PATCH v5 0/8] Add support for the LAN966x PCI device using a DT overlay

[Philipp Zabel]

On Do, 2024-08-08 at 17:46 +0200, Herve Codina wrote:
> Hi,
> 
[...]
>  - Patches 3 to 8 allow the reset driver used for the LAN996x to be
>    built as a module. Indeed, in the case where Linux runs on the ARM
>    cores, it is common to have the reset driver built-in. However, when
>    the LAN996x is used as a PCI device, it makes sense that all its
>    drivers can be loaded as modules.

I've applied patch 7 to reset/next.

regards
Philipp

Re: [PATCH v5 0/8] Add support for the LAN966x PCI device using a DT overlay

[Herve Codina]

Hi,

On Thu,  8 Aug 2024 17:46:49 +0200
Herve Codina <herve.codina@bootlin.com> wrote:

...

> In order to add this PCI driver, a number of preparation changes are
> needed:
>  - Patches 1, 2 introduce the LAN996x PCI driver itself, together with
>    its DT overlay and the related MAINTAINTER entry.
> 
>  - Patches 3 to 8 allow the reset driver used for the LAN996x to be
>    built as a module. Indeed, in the case where Linux runs on the ARM
>    cores, it is common to have the reset driver built-in. However, when
>    the LAN996x is used as a PCI device, it makes sense that all its
>    drivers can be loaded as modules.
> 

Patch 7 was applied my Philipp and patch 1 was acked by Greg.

No feedback received on other patches.
What can I do to move forward on this series and have it applied ?

Best regards,
Hervé

Re: [PATCH v5 0/8] Add support for the LAN966x PCI device using a DT overlay

[Lee Jones]

On Tue, 03 Sep 2024, Herve Codina wrote:

> Hi,
> 
> On Thu,  8 Aug 2024 17:46:49 +0200
> Herve Codina <herve.codina@bootlin.com> wrote:
> 
> ...
> 
> > In order to add this PCI driver, a number of preparation changes are
> > needed:
> >  - Patches 1, 2 introduce the LAN996x PCI driver itself, together with
> >    its DT overlay and the related MAINTAINTER entry.
> > 
> >  - Patches 3 to 8 allow the reset driver used for the LAN996x to be
> >    built as a module. Indeed, in the case where Linux runs on the ARM
> >    cores, it is common to have the reset driver built-in. However, when
> >    the LAN996x is used as a PCI device, it makes sense that all its
> >    drivers can be loaded as modules.
> > 
> 
> Patch 7 was applied my Philipp and patch 1 was acked by Greg.
> 
> No feedback received on other patches.
> What can I do to move forward on this series and have it applied ?

Arnd needs to be okay with the syscon ref-counting idea.

-- 
Lee Jones [李琼斯]

Re: [PATCH v5 3/8] mfd: syscon: Add reference counting and device managed support

[Lee Jones]

On Thu, 08 Aug 2024, Herve Codina wrote:

> From: Clément Léger <clement.leger@bootlin.com>
> 
> Syscon releasing is not supported.
> Without release function, unbinding a driver that uses syscon whether
> explicitly or due to a module removal left the used syscon in a in-use
> state.
> 
> For instance a syscon_node_to_regmap() call from a consumer retrieves a
> syscon regmap instance. Internally, syscon_node_to_regmap() can create
> syscon instance and add it to the existing syscon list. No API is
> available to release this syscon instance, remove it from the list and
> free it when it is not used anymore.
> 
> Introduce reference counting in syscon in order to keep track of syscon
> usage using syscon_{get,put}() and add a device managed version of
> syscon_regmap_lookup_by_phandle(), to automatically release the syscon
> instance on the consumer removal.
> 
> Signed-off-by: Clément Léger <clement.leger@bootlin.com>
> Signed-off-by: Herve Codina <herve.codina@bootlin.com>
> ---
>  drivers/mfd/syscon.c       | 138 ++++++++++++++++++++++++++++++++++---
>  include/linux/mfd/syscon.h |  16 +++++
>  2 files changed, 144 insertions(+), 10 deletions(-)

This doesn't look very popular.

What are the potential ramifications for existing users?

-- 
Lee Jones [李琼斯]

Re: [PATCH v5 3/8] mfd: syscon: Add reference counting and device managed support

[Herve Codina]

Hi Lee,

On Tue, 3 Sep 2024 16:38:39 +0100
Lee Jones <lee@kernel.org> wrote:

> On Thu, 08 Aug 2024, Herve Codina wrote:
> 
> > From: Clément Léger <clement.leger@bootlin.com>
> > 
> > Syscon releasing is not supported.
> > Without release function, unbinding a driver that uses syscon whether
> > explicitly or due to a module removal left the used syscon in a in-use
> > state.
> > 
> > For instance a syscon_node_to_regmap() call from a consumer retrieves a
> > syscon regmap instance. Internally, syscon_node_to_regmap() can create
> > syscon instance and add it to the existing syscon list. No API is
> > available to release this syscon instance, remove it from the list and
> > free it when it is not used anymore.
> > 
> > Introduce reference counting in syscon in order to keep track of syscon
> > usage using syscon_{get,put}() and add a device managed version of
> > syscon_regmap_lookup_by_phandle(), to automatically release the syscon
> > instance on the consumer removal.
> > 
> > Signed-off-by: Clément Léger <clement.leger@bootlin.com>
> > Signed-off-by: Herve Codina <herve.codina@bootlin.com>
> > ---
> >  drivers/mfd/syscon.c       | 138 ++++++++++++++++++++++++++++++++++---
> >  include/linux/mfd/syscon.h |  16 +++++
> >  2 files changed, 144 insertions(+), 10 deletions(-)  
> 
> This doesn't look very popular.
> 
> What are the potential ramifications for existing users?
> 

Existing user don't use devm_syscon_regmap_lookup_by_phandle() nor
syscon_put_regmap().

So refcount is incremented but never decremented. syscon is never
released. Exactly the same as current implementation.
Nothing change for existing users.

Best regards,
Hervé

Re: [PATCH v5 1/8] misc: Add support for LAN966x PCI device

[Herve Codina]

Hi Greg, Rob,

On Tue, 13 Aug 2024 11:57:15 +0200
Greg Kroah-Hartman <gregkh@linuxfoundation.org> wrote:

> On Thu, Aug 08, 2024 at 05:46:50PM +0200, Herve Codina wrote:
> > Add a PCI driver that handles the LAN966x PCI device using a device-tree
> > overlay. This overlay is applied to the PCI device DT node and allows to
> > describe components that are present in the device.
> > 
> > The memory from the device-tree is remapped to the BAR memory thanks to
> > "ranges" properties computed at runtime by the PCI core during the PCI
> > enumeration.
> > 
> > The PCI device itself acts as an interrupt controller and is used as the
> > parent of the internal LAN966x interrupt controller to route the
> > interrupts to the assigned PCI INTx interrupt.
> > 
> > Signed-off-by: Herve Codina <herve.codina@bootlin.com>  
> 
> misc device is fine, even if it's not really one :)
> 
> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

I didn't receive other feedback on this patch.

Is there anything blocking to have it applied?

Best regards,
Hervé

Re: [PATCH v5 3/8] mfd: syscon: Add reference counting and device managed support

[Herve Codina]

Hi Lee, Arnd,

On Tue, 3 Sep 2024 18:01:16 +0200
Herve Codina <herve.codina@bootlin.com> wrote:

> Hi Lee,
> 
> On Tue, 3 Sep 2024 16:38:39 +0100
> Lee Jones <lee@kernel.org> wrote:
> 
> > On Thu, 08 Aug 2024, Herve Codina wrote:
> >   
> > > From: Clément Léger <clement.leger@bootlin.com>
> > > 
> > > Syscon releasing is not supported.
> > > Without release function, unbinding a driver that uses syscon whether
> > > explicitly or due to a module removal left the used syscon in a in-use
> > > state.
> > > 
> > > For instance a syscon_node_to_regmap() call from a consumer retrieves a
> > > syscon regmap instance. Internally, syscon_node_to_regmap() can create
> > > syscon instance and add it to the existing syscon list. No API is
> > > available to release this syscon instance, remove it from the list and
> > > free it when it is not used anymore.
> > > 
> > > Introduce reference counting in syscon in order to keep track of syscon
> > > usage using syscon_{get,put}() and add a device managed version of
> > > syscon_regmap_lookup_by_phandle(), to automatically release the syscon
> > > instance on the consumer removal.
> > > 
> > > Signed-off-by: Clément Léger <clement.leger@bootlin.com>
> > > Signed-off-by: Herve Codina <herve.codina@bootlin.com>
> > > ---
> > >  drivers/mfd/syscon.c       | 138 ++++++++++++++++++++++++++++++++++---
> > >  include/linux/mfd/syscon.h |  16 +++++
> > >  2 files changed, 144 insertions(+), 10 deletions(-)    
> > 
> > This doesn't look very popular.
> > 
> > What are the potential ramifications for existing users?
> >   
> 
> Existing user don't use devm_syscon_regmap_lookup_by_phandle() nor
> syscon_put_regmap().
> 
> So refcount is incremented but never decremented. syscon is never
> released. Exactly the same as current implementation.
> Nothing change for existing users.
> 
> Best regards,
> Hervé

I hope I answered to Lee's question related to possible impacts on
existing drivers.

Is there anything else that blocks this patch from being applied ?

Best regards,
Hervé

Re: [PATCH v5 3/8] mfd: syscon: Add reference counting and device managed support

[Lee Jones]

On Mon, 09 Sep 2024, Herve Codina wrote:

> Hi Lee, Arnd,
> 
> On Tue, 3 Sep 2024 18:01:16 +0200
> Herve Codina <herve.codina@bootlin.com> wrote:
> 
> > Hi Lee,
> > 
> > On Tue, 3 Sep 2024 16:38:39 +0100
> > Lee Jones <lee@kernel.org> wrote:
> > 
> > > On Thu, 08 Aug 2024, Herve Codina wrote:
> > >   
> > > > From: Clément Léger <clement.leger@bootlin.com>
> > > > 
> > > > Syscon releasing is not supported.
> > > > Without release function, unbinding a driver that uses syscon whether
> > > > explicitly or due to a module removal left the used syscon in a in-use
> > > > state.
> > > > 
> > > > For instance a syscon_node_to_regmap() call from a consumer retrieves a
> > > > syscon regmap instance. Internally, syscon_node_to_regmap() can create
> > > > syscon instance and add it to the existing syscon list. No API is
> > > > available to release this syscon instance, remove it from the list and
> > > > free it when it is not used anymore.
> > > > 
> > > > Introduce reference counting in syscon in order to keep track of syscon
> > > > usage using syscon_{get,put}() and add a device managed version of
> > > > syscon_regmap_lookup_by_phandle(), to automatically release the syscon
> > > > instance on the consumer removal.
> > > > 
> > > > Signed-off-by: Clément Léger <clement.leger@bootlin.com>
> > > > Signed-off-by: Herve Codina <herve.codina@bootlin.com>
> > > > ---
> > > >  drivers/mfd/syscon.c       | 138 ++++++++++++++++++++++++++++++++++---
> > > >  include/linux/mfd/syscon.h |  16 +++++
> > > >  2 files changed, 144 insertions(+), 10 deletions(-)    
> > > 
> > > This doesn't look very popular.
> > > 
> > > What are the potential ramifications for existing users?
> > >   
> > 
> > Existing user don't use devm_syscon_regmap_lookup_by_phandle() nor
> > syscon_put_regmap().
> > 
> > So refcount is incremented but never decremented. syscon is never
> > released. Exactly the same as current implementation.
> > Nothing change for existing users.
> > 
> > Best regards,
> > Hervé
> 
> I hope I answered to Lee's question related to possible impacts on
> existing drivers.
> 
> Is there anything else that blocks this patch from being applied ?

Arnd usually takes care of Syscon reviews.

Perhaps he's out on vacation.

Let's wait a little longer, since it's too late for this cycle anyway.

-- 
Lee Jones [李琼斯]

Re: [PATCH v5 1/8] misc: Add support for LAN966x PCI device

[Bjorn Helgaas]

On Thu, Aug 08, 2024 at 05:46:50PM +0200, Herve Codina wrote:
> Add a PCI driver that handles the LAN966x PCI device using a device-tree
> overlay. This overlay is applied to the PCI device DT node and allows to
> describe components that are present in the device.
> 
> The memory from the device-tree is remapped to the BAR memory thanks to
> "ranges" properties computed at runtime by the PCI core during the PCI
> enumeration.
> 
> The PCI device itself acts as an interrupt controller and is used as the
> parent of the internal LAN966x interrupt controller to route the
> interrupts to the assigned PCI INTx interrupt.
> 
> Signed-off-by: Herve Codina <herve.codina@bootlin.com>
> ---
>  drivers/misc/Kconfig          |  24 ++++
>  drivers/misc/Makefile         |   3 +
>  drivers/misc/lan966x_pci.c    | 215 ++++++++++++++++++++++++++++++++++
>  drivers/misc/lan966x_pci.dtso | 167 ++++++++++++++++++++++++++
>  drivers/pci/quirks.c          |   1 +

Acked-by: Bjorn Helgaas <bhelgaas@google.com> # drivers/pci/quirks.c

> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
> index a2ce4e08edf5..bae2dd99017c 100644
> --- a/drivers/pci/quirks.c
> +++ b/drivers/pci/quirks.c
> @@ -6245,6 +6245,7 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0xa76e, dpc_log_size);
>  DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_XILINX, 0x5020, of_pci_make_dev_node);
>  DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_XILINX, 0x5021, of_pci_make_dev_node);
>  DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_REDHAT, 0x0005, of_pci_make_dev_node);
> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_EFAR, 0x9660, of_pci_make_dev_node);
>  
>  /*
>   * Devices known to require a longer delay before first config space access
> -- 
> 2.45.0
> 

Re: [PATCH v5 3/8] mfd: syscon: Add reference counting and device managed support

[Herve Codina]

Hi,

On Thu, 12 Sep 2024 15:37:40 +0100
Lee Jones <lee@kernel.org> wrote:

> On Mon, 09 Sep 2024, Herve Codina wrote:
> 
> > Hi Lee, Arnd,
> > 
> > On Tue, 3 Sep 2024 18:01:16 +0200
> > Herve Codina <herve.codina@bootlin.com> wrote:
> >   
> > > Hi Lee,
> > > 
> > > On Tue, 3 Sep 2024 16:38:39 +0100
> > > Lee Jones <lee@kernel.org> wrote:
> > >   
> > > > On Thu, 08 Aug 2024, Herve Codina wrote:
> > > >     
> > > > > From: Clément Léger <clement.leger@bootlin.com>
> > > > > 
> > > > > Syscon releasing is not supported.
> > > > > Without release function, unbinding a driver that uses syscon whether
> > > > > explicitly or due to a module removal left the used syscon in a in-use
> > > > > state.
> > > > > 
> > > > > For instance a syscon_node_to_regmap() call from a consumer retrieves a
> > > > > syscon regmap instance. Internally, syscon_node_to_regmap() can create
> > > > > syscon instance and add it to the existing syscon list. No API is
> > > > > available to release this syscon instance, remove it from the list and
> > > > > free it when it is not used anymore.
> > > > > 
> > > > > Introduce reference counting in syscon in order to keep track of syscon
> > > > > usage using syscon_{get,put}() and add a device managed version of
> > > > > syscon_regmap_lookup_by_phandle(), to automatically release the syscon
> > > > > instance on the consumer removal.
> > > > > 
> > > > > Signed-off-by: Clément Léger <clement.leger@bootlin.com>
> > > > > Signed-off-by: Herve Codina <herve.codina@bootlin.com>
> > > > > ---
> > > > >  drivers/mfd/syscon.c       | 138 ++++++++++++++++++++++++++++++++++---
> > > > >  include/linux/mfd/syscon.h |  16 +++++
> > > > >  2 files changed, 144 insertions(+), 10 deletions(-)      
> > > > 
> > > > This doesn't look very popular.
> > > > 
> > > > What are the potential ramifications for existing users?
> > > >     
> > > 
> > > Existing user don't use devm_syscon_regmap_lookup_by_phandle() nor
> > > syscon_put_regmap().
> > > 
> > > So refcount is incremented but never decremented. syscon is never
> > > released. Exactly the same as current implementation.
> > > Nothing change for existing users.
> > > 
> > > Best regards,
> > > Hervé  
> > 
> > I hope I answered to Lee's question related to possible impacts on
> > existing drivers.
> > 
> > Is there anything else that blocks this patch from being applied ?  
> 
> Arnd usually takes care of Syscon reviews.
> 
> Perhaps he's out on vacation.
> 
> Let's wait a little longer, since it's too late for this cycle anyway.
> 

Discussed the topic with Arnd Bergmann at Linux Plumbers Conference.
Adding ref-counting and support for removal in syscon is rejected by Arnd.

For my LAN966x use case (syscon is used only by the reset controller), the
solution is to remove the syscon device and handle directly the reset protect
register in the reset controller itself.

I will propose modifications in that way in the next iteration.

Regards,
Hervé