[PATCH v9 net-next 0/7] add support for VSC7512 control over SPI

[PATCH v9 net-next 0/7] add support for VSC7512 control over SPI

[Colin Foster]

The patch set in general is to add support for the VSC7512, and
eventually the VSC7511, VSC7513 and VSC7514 devices controlled over
SPI. Specifically this patch set enables pinctrl, serial gpio expander
access, and control of an internal and an external MDIO bus.

I have mentioned previously:
The hardware setup I'm using for development is a beaglebone black, with
jumpers from SPI0 to the microchip VSC7512 dev board. The microchip dev
board has been modified to not boot from flash, but wait for SPI. An
ethernet cable is connected from the beaglebone ethernet to port 0 of
the dev board. Network functionality will be included in a future patch set.

The device tree I'm using is included in the documentation, so I'll not
include that in this cover letter. I have exported the serial GPIOs to the
LEDs, and verified functionality via
"echo heartbeat > sys/class/leds/port0led/trigger"

/ {
	vscleds {
		compatible = "gpio-leds";
		vscled@0 {
			label = "port0led";
			gpios = <&sgpio_out1 0 0 GPIO_ACTIVE_LOW>;
			default-state = "off";
		};
		vscled@1 {
			label = "port0led1";
			gpios = <&sgpio_out1 0 1 GPIO_ACTIVE_LOW>;
			default-state = "off";
		};
[ ... ]
	};
};

And I'll include the relevant dmesg prints - I don't love the "invalid
resource" prints, as they seem to be misleading. They're a byproduct of
looking for IO resources before falling back to REG, which succeeds.

[    0.000000] Booting Linux on physical CPU 0x0
[    0.000000] Linux version 5.18.0-12138-g89bf3be45d34 (colin@euler) (arm-linux-gnueabi-gcc (Ubuntu 9.4.0-1ubuntu1~20.04.1) 9.4.0, GNU ld (GNU Binutils for Ubuntu) 2.34) #702 SMP PREEMPT Fri Jun 10 10:12:20 PDT 2022
...
[    1.923330] pinctrl-ocelot ocelot-pinctrl.0.auto: DMA mask not set
[    1.923498] pinctrl-ocelot ocelot-pinctrl.0.auto: invalid resource
[    1.935102] pinctrl-ocelot ocelot-pinctrl.0.auto: driver registered
[    1.954499] pinctrl-microchip-sgpio ocelot-sgpio.1.auto: DMA mask not set
[    1.954708] pinctrl-microchip-sgpio ocelot-sgpio.1.auto: invalid resource
[    1.966000] mscc-miim ocelot-miim0.2.auto: DMA mask not set
[    1.966154] mscc-miim ocelot-miim0.2.auto: invalid resource
[    1.966307] mscc-miim ocelot-miim0.2.auto: invalid resource
[    2.995959] mscc-miim ocelot-miim1.3.auto: DMA mask not set
[    2.996118] mscc-miim ocelot-miim1.3.auto: invalid resource
[    2.996274] mscc-miim ocelot-miim1.3.auto: invalid resource
[    2.996286] mscc-miim ocelot-miim1.3.auto: error 00000000: Failed to get resource

Lastly, I removed the Kconfig tristate patches for pinctrl and ocelot-mfd.
They broke the last RFC build, so I'll probably want to add that at a
later time.


I only have hardware to test the last patch, so any testers are welcome.
I've been extra cautious about the
ocelot_platform_init_regmap_from_resource helper function, both before
and after the last patch. I accidentally broke it in the past and would
like to avoid doing so again.


RFC history:
v1 (accidentally named vN)
	* Initial architecture. Not functional
	* General concepts laid out

v2
	* Near functional. No CPU port communication, but control over all
	external ports
	* Cleaned up regmap implementation from v1

v3
	* Functional
	* Shared MDIO transactions routed through mdio-mscc-miim
	* CPU / NPI port enabled by way of vsc7512_enable_npi_port /
	felix->info->enable_npi_port
	* NPI port tagging functional - Requires a CPU port driver that supports
	frames of 1520 bytes. Verified with a patch to the cpsw driver

v4
    * Functional
    * Device tree fixes
    * Add hooks for pinctrl-ocelot - some functionality by way of sysfs
    * Add hooks for pinctrl-microsemi-sgpio - not yet fully functional
    * Remove lynx_pcs interface for a generic phylink_pcs. The goal here
    is to have an ocelot_pcs that will work for each configuration of
    every port.

v5
    * Restructured to MFD
    * Several commits were split out, submitted, and accepted
    * pinctrl-ocelot believed to be fully functional (requires commits
    from the linux-pinctrl tree)
    * External MDIO bus believed to be fully functional

v6
    * Applied several suggestions from the last RFC from Lee Jones. I
      hope I didn't miss anything.
    * Clean up MFD core - SPI interaction. They no longer use callbacks.
    * regmaps get registered to the child device, and don't attempt to
      get shared. It seems if a regmap is to be shared, that should be
      solved with syscon, not dev or mfd.

v7
    * Applied as much as I could from Lee and Vladimir's suggestions. As
      always, the feedback is greatly appreciated!
    * Remove "ocelot_spi" container complication
    * Move internal MDIO bus from ocelot_ext to MFD, with a devicetree
      change to match
    * Add initial HSIO support
    * Switch to IORESOURCE_REG for resource definitions

v8
    * Applied another round of suggestions from Lee and Vladimir
    * Utilize regmap bus reads, which speeds bulk transfers up by an
      order of magnitude
    * Add two additional patches to utilize phylink_generic_validate
    * Changed GPL V2 to GPL in licenses where applicable (checkpatch)
    * Remove initial hsio/serdes changes from the RFC

v9
    * Submitting as a PATCH instead of an RFC
    * Remove switch functionality - will be a separate patch set
    * Remove Kconfig tristate module options
    * Another round of suggestions from Lee, Vladimir, and Andy. Many
      thanks!
    * Add documentation
    * Update maintainers


Colin Foster (7):
  mfd: ocelot: add helper to get regmap from a resource
  net: mdio: mscc-miim: add ability to be used in a non-mmio
    configuration
  pinctrl: ocelot: add ability to be used in a non-mmio configuration
  pinctrl: microchip-sgpio: add ability to be used in a non-mmio
    configuration
  resource: add define macro for register address resources
  dt-bindings: mfd: ocelot: add bindings for VSC7512
  mfd: ocelot: add support for the vsc7512 chip via spi

 .../devicetree/bindings/mfd/mscc,ocelot.yaml  | 160 +++++++++
 MAINTAINERS                                   |   7 +
 drivers/mfd/Kconfig                           |  18 +
 drivers/mfd/Makefile                          |   2 +
 drivers/mfd/ocelot-core.c                     | 184 ++++++++++
 drivers/mfd/ocelot-spi.c                      | 313 ++++++++++++++++++
 drivers/mfd/ocelot.h                          |  28 ++
 drivers/net/mdio/mdio-mscc-miim.c             |  27 +-
 drivers/pinctrl/pinctrl-microchip-sgpio.c     |   9 +-
 drivers/pinctrl/pinctrl-ocelot.c              |  10 +-
 include/linux/ioport.h                        |   5 +
 include/linux/mfd/ocelot.h                    |  32 ++
 12 files changed, 763 insertions(+), 32 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/mfd/mscc,ocelot.yaml
 create mode 100644 drivers/mfd/ocelot-core.c
 create mode 100644 drivers/mfd/ocelot-spi.c
 create mode 100644 drivers/mfd/ocelot.h
 create mode 100644 include/linux/mfd/ocelot.h

-- 
2.25.1

[PATCH v9 net-next 1/7] mfd: ocelot: add helper to get regmap from a resource

[Colin Foster]

Several ocelot-related modules are designed for MMIO / regmaps. As such,
they often use a combination of devm_platform_get_and_ioremap_resource and
devm_regmap_init_mmio.

Operating in an MFD might be different, in that it could be memory mapped,
or it could be SPI, I2C... In these cases a fallback to use IORESOURCE_REG
instead of IORESOURCE_MEM becomes necessary.

When this happens, there's redundant logic that needs to be implemented in
every driver. In order to avoid this redundancy, utilize a single function
that, if the MFD scenario is enabled, will perform this fallback logic.

Signed-off-by: Colin Foster <colin.foster@in-advantage.com>
---
 MAINTAINERS                |  5 +++++
 include/linux/mfd/ocelot.h | 22 ++++++++++++++++++++++
 2 files changed, 27 insertions(+)
 create mode 100644 include/linux/mfd/ocelot.h

diff --git a/MAINTAINERS b/MAINTAINERS
index 033a01b07f8f..91b4151c5ad1 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -14352,6 +14352,11 @@ F:	net/dsa/tag_ocelot.c
 F:	net/dsa/tag_ocelot_8021q.c
 F:	tools/testing/selftests/drivers/net/ocelot/*
 
+OCELOT EXTERNAL SWITCH CONTROL
+M:	Colin Foster <colin.foster@in-advantage.com>
+S:	Supported
+F:	include/linux/mfd/ocelot.h
+
 OCXL (Open Coherent Accelerator Processor Interface OpenCAPI) DRIVER
 M:	Frederic Barrat <fbarrat@linux.ibm.com>
 M:	Andrew Donnellan <ajd@linux.ibm.com>
diff --git a/include/linux/mfd/ocelot.h b/include/linux/mfd/ocelot.h
new file mode 100644
index 000000000000..40e775f1143f
--- /dev/null
+++ b/include/linux/mfd/ocelot.h
@@ -0,0 +1,22 @@
+/* SPDX-License-Identifier: GPL-2.0 OR MIT */
+/* Copyright 2022 Innovative Advantage Inc. */
+
+#include <linux/err.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+static inline void
+ocelot_platform_init_regmap_from_resource(struct platform_device *pdev,
+					  unsigned int index,
+					  struct regmap **map,
+					  struct resource **res,
+					  const struct regmap_config *config);
+{
+	u32 __iomem *regs =
+		devm_platform_get_and_ioremap_resource(pdev, index, res);
+
+	if (!IS_ERR(regs))
+		*map = devm_regmap_init_mmio(&pdev->dev, regs, config);
+	else
+		*map = ERR_PTR(ENODEV);
+}
-- 
2.25.1

[PATCH v9 net-next 2/7] net: mdio: mscc-miim: add ability to be used in a non-mmio configuration

[Colin Foster]

There are a few Ocelot chips that contain the logic for this bus, but are
controlled externally. Specifically the VSC7511, 7512, 7513, and 7514. In
the externally controlled configurations these registers are not
memory-mapped.

Add support for these non-memory-mapped configurations.

Signed-off-by: Colin Foster <colin.foster@in-advantage.com>
---
 drivers/net/mdio/mdio-mscc-miim.c | 27 ++++++++-------------------
 1 file changed, 8 insertions(+), 19 deletions(-)

diff --git a/drivers/net/mdio/mdio-mscc-miim.c b/drivers/net/mdio/mdio-mscc-miim.c
index 08541007b18a..cd89a313cf82 100644
--- a/drivers/net/mdio/mdio-mscc-miim.c
+++ b/drivers/net/mdio/mdio-mscc-miim.c
@@ -12,6 +12,7 @@
 #include <linux/iopoll.h>
 #include <linux/kernel.h>
 #include <linux/mdio/mdio-mscc-miim.h>
+#include <linux/mfd/ocelot.h>
 #include <linux/module.h>
 #include <linux/of_mdio.h>
 #include <linux/phy.h>
@@ -270,43 +271,31 @@ static int mscc_miim_clk_set(struct mii_bus *bus)
 
 static int mscc_miim_probe(struct platform_device *pdev)
 {
-	struct regmap *mii_regmap, *phy_regmap = NULL;
 	struct device_node *np = pdev->dev.of_node;
+	struct regmap *mii_regmap, *phy_regmap;
 	struct device *dev = &pdev->dev;
-	void __iomem *regs, *phy_regs;
 	struct mscc_miim_dev *miim;
 	struct resource *res;
 	struct mii_bus *bus;
 	int ret;
 
-	regs = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
-	if (IS_ERR(regs)) {
-		dev_err(dev, "Unable to map MIIM registers\n");
-		return PTR_ERR(regs);
-	}
-
-	mii_regmap = devm_regmap_init_mmio(dev, regs, &mscc_miim_regmap_config);
-
+	ocelot_platform_init_regmap_from_resource(pdev, 0, &mii_regmap, NULL,
+						  &mscc_miim_regmap_config);
 	if (IS_ERR(mii_regmap)) {
 		dev_err(dev, "Unable to create MIIM regmap\n");
 		return PTR_ERR(mii_regmap);
 	}
 
 	/* This resource is optional */
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	ocelot_platform_init_regmap_from_resource(pdev, 1, &phy_regmap, &res,
+						  &mscc_miim_phy_regmap_config);
 	if (res) {
-		phy_regs = devm_ioremap_resource(dev, res);
-		if (IS_ERR(phy_regs)) {
-			dev_err(dev, "Unable to map internal phy registers\n");
-			return PTR_ERR(phy_regs);
-		}
-
-		phy_regmap = devm_regmap_init_mmio(dev, phy_regs,
-						   &mscc_miim_phy_regmap_config);
 		if (IS_ERR(phy_regmap)) {
 			dev_err(dev, "Unable to create phy register regmap\n");
 			return PTR_ERR(phy_regmap);
 		}
+	} else {
+		phy_regmap = NULL;
 	}
 
 	ret = mscc_miim_setup(dev, &bus, "mscc_miim", mii_regmap, 0);
-- 
2.25.1

[PATCH v9 net-next 3/7] pinctrl: ocelot: add ability to be used in a non-mmio configuration

[Colin Foster]

There are a few Ocelot chips that contain pinctrl logic, but can be
controlled externally. Specifically the VSC7511, 7512, 7513 and 7514. In
the externally controlled configurations these registers are not
memory-mapped.

Add support for these non-memory-mapped configurations.

Signed-off-by: Colin Foster <colin.foster@in-advantage.com>
---
 drivers/pinctrl/pinctrl-ocelot.c | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/drivers/pinctrl/pinctrl-ocelot.c b/drivers/pinctrl/pinctrl-ocelot.c
index 5f4a8c5c6650..7ac12102120f 100644
--- a/drivers/pinctrl/pinctrl-ocelot.c
+++ b/drivers/pinctrl/pinctrl-ocelot.c
@@ -10,6 +10,7 @@
 #include <linux/gpio/driver.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
+#include <linux/mfd/ocelot.h>
 #include <linux/of_device.h>
 #include <linux/of_irq.h>
 #include <linux/of_platform.h>
@@ -1917,7 +1918,6 @@ static int ocelot_pinctrl_probe(struct platform_device *pdev)
 	struct ocelot_pinctrl *info;
 	struct reset_control *reset;
 	struct regmap *pincfg;
-	void __iomem *base;
 	int ret;
 	struct regmap_config regmap_config = {
 		.reg_bits = 32,
@@ -1937,16 +1937,12 @@ static int ocelot_pinctrl_probe(struct platform_device *pdev)
 				     "Failed to get reset\n");
 	reset_control_reset(reset);
 
-	base = devm_ioremap_resource(dev,
-			platform_get_resource(pdev, IORESOURCE_MEM, 0));
-	if (IS_ERR(base))
-		return PTR_ERR(base);
-
 	info->stride = 1 + (info->desc->npins - 1) / 32;
 
 	regmap_config.max_register = OCELOT_GPIO_SD_MAP * info->stride + 15 * 4;
 
-	info->map = devm_regmap_init_mmio(dev, base, &regmap_config);
+	ocelot_platform_init_regmap_from_resource(pdev, 0, &info->map, NULL,
+						  &regmap_config);
 	if (IS_ERR(info->map)) {
 		dev_err(dev, "Failed to create regmap\n");
 		return PTR_ERR(info->map);
-- 
2.25.1

[PATCH v9 net-next 4/7] pinctrl: microchip-sgpio: add ability to be used in a non-mmio configuration

[Colin Foster]

There are a few Ocelot chips that can contain SGPIO logic, but can be
controlled externally. Specifically the VSC7511, 7512, 7513, and 7514. In
the externally controlled configurations these registers are not
memory-mapped.

Add support for these non-memory-mapped configurations.

Signed-off-by: Colin Foster <colin.foster@in-advantage.com>
---
 drivers/pinctrl/pinctrl-microchip-sgpio.c | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/drivers/pinctrl/pinctrl-microchip-sgpio.c b/drivers/pinctrl/pinctrl-microchip-sgpio.c
index 6f55bf7d5e05..25fe57a0c26e 100644
--- a/drivers/pinctrl/pinctrl-microchip-sgpio.c
+++ b/drivers/pinctrl/pinctrl-microchip-sgpio.c
@@ -12,6 +12,7 @@
 #include <linux/clk.h>
 #include <linux/gpio/driver.h>
 #include <linux/io.h>
+#include <linux/mfd/ocelot.h>
 #include <linux/mod_devicetable.h>
 #include <linux/module.h>
 #include <linux/pinctrl/pinmux.h>
@@ -904,7 +905,6 @@ static int microchip_sgpio_probe(struct platform_device *pdev)
 	struct reset_control *reset;
 	struct sgpio_priv *priv;
 	struct clk *clk;
-	u32 __iomem *regs;
 	u32 val;
 	struct regmap_config regmap_config = {
 		.reg_bits = 32,
@@ -937,11 +937,8 @@ static int microchip_sgpio_probe(struct platform_device *pdev)
 		return -EINVAL;
 	}
 
-	regs = devm_platform_ioremap_resource(pdev, 0);
-	if (IS_ERR(regs))
-		return PTR_ERR(regs);
-
-	priv->regs = devm_regmap_init_mmio(dev, regs, &regmap_config);
+	ocelot_platform_init_regmap_from_resource(pdev, 0, &priv->regs, NULL,
+						  &regmap_config);
 	if (IS_ERR(priv->regs))
 		return PTR_ERR(priv->regs);
 
-- 
2.25.1

[PATCH v9 net-next 5/7] resource: add define macro for register address resources

[Colin Foster]

DEFINE_RES_ macros have been created for the commonly used resource types,
but not IORESOURCE_REG. Add the macro so it can be used in a similar manner
to all other resource types.

Signed-off-by: Colin Foster <colin.foster@in-advantage.com>
---
 include/linux/ioport.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/include/linux/ioport.h b/include/linux/ioport.h
index ec5f71f7135b..f3b0e238c020 100644
--- a/include/linux/ioport.h
+++ b/include/linux/ioport.h
@@ -171,6 +171,11 @@ enum {
 #define DEFINE_RES_MEM(_start, _size)					\
 	DEFINE_RES_MEM_NAMED((_start), (_size), NULL)
 
+#define DEFINE_RES_REG_NAMED(_start, _size, _name)			\
+	DEFINE_RES_NAMED((_start), (_size), (_name), IORESOURCE_REG)
+#define DEFINE_RES_REG(_start, _size)					\
+	DEFINE_RES_MEM_NAMED((_start), (_size), NULL)
+
 #define DEFINE_RES_IRQ_NAMED(_irq, _name)				\
 	DEFINE_RES_NAMED((_irq), 1, (_name), IORESOURCE_IRQ)
 #define DEFINE_RES_IRQ(_irq)						\
-- 
2.25.1

[PATCH v9 net-next 6/7] dt-bindings: mfd: ocelot: add bindings for VSC7512

[Colin Foster]

Add devicetree bindings for SPI-controlled Ocelot chips, specifically the
VSC7512.

Signed-off-by: Colin Foster <colin.foster@in-advantage.com>
---
 .../devicetree/bindings/mfd/mscc,ocelot.yaml  | 160 ++++++++++++++++++
 MAINTAINERS                                   |   1 +
 2 files changed, 161 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mfd/mscc,ocelot.yaml

diff --git a/Documentation/devicetree/bindings/mfd/mscc,ocelot.yaml b/Documentation/devicetree/bindings/mfd/mscc,ocelot.yaml
new file mode 100644
index 000000000000..e298ca8d616d
--- /dev/null
+++ b/Documentation/devicetree/bindings/mfd/mscc,ocelot.yaml
@@ -0,0 +1,160 @@
+# SPDX-License-Identifier: GPL-2.0 OR BSD-2-Clause */
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mfd/mscc,ocelot.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Ocelot Externally-Controlled Ethernet Switch
+
+maintainers:
+  - Colin Foster <colin.foster@in-advantage.com>
+
+description: |
+  The Ocelot ethernet switch family contains chips that have an internal CPU
+  (VSC7513, VSC7514) and chips that don't (VSC7511, VSC7512). All switches have
+  the option to be controlled externally, which is the purpose of this driver.
+
+  The switch family is a multi-port networking switch that supports many
+  interfaces. Additionally, the device can perform pin control, MDIO buses, and
+  external GPIO expanders.
+
+properties:
+  compatible:
+    enum:
+      - mscc,vsc7512-spi
+
+  reg:
+    maxItems: 1
+
+  "#address-cells":
+    const: 1
+
+  "#size-cells":
+    const: 0
+
+  spi-max-frequency:
+    maxItems: 1
+
+patternProperties:
+  "^pinctrl@[0-9a-f]+$":
+    type: object
+    $ref: /schemas/pinctrl/mscc,ocelot-pinctrl.yaml
+
+  "^gpio@[0-9a-f]+$":
+    type: object
+    $ref: /schemas/pinctrl/microchip,sparx5-sgpio.yaml
+    properties:
+      compatible:
+        enum:
+          - mscc,ocelot-sgpio
+
+  "^mdio@[0-9a-f]+$":
+    type: object
+    $ref: /schemas/net/mscc,miim.yaml
+    properties:
+      compatible:
+        enum:
+          - mscc,ocelot-miim
+
+required:
+  - compatible
+  - reg
+  - '#address-cells'
+  - '#size-cells'
+  - spi-max-frequency
+
+additionalProperties: false
+
+examples:
+  - |
+    ocelot_clock: ocelot-clock {
+          compatible = "fixed-clock";
+          #clock-cells = <0>;
+          clock-frequency = <125000000>;
+      };
+
+    spi0 {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        ocelot-chip@0 {
+            compatible = "mscc,vsc7512-spi";
+            spi-max-frequency = <2500000>;
+            reg = <0>;
+            #address-cells = <1>;
+            #size-cells = <0>;
+
+            mdio0: mdio@7107009c {
+                compatible = "mscc,ocelot-miim";
+                #address-cells = <1>;
+                #size-cells = <0>;
+                reg = <0x7107009c>;
+
+                sw_phy0: ethernet-phy@0 {
+                    reg = <0x0>;
+                };
+            };
+
+            mdio1: mdio@710700c0 {
+                compatible = "mscc,ocelot-miim";
+                pinctrl-names = "default";
+                pinctrl-0 = <&miim1_pins>;
+                #address-cells = <1>;
+                #size-cells = <0>;
+                reg = <0x710700c0>;
+
+                sw_phy4: ethernet-phy@4 {
+                    reg = <0x4>;
+                };
+            };
+
+            gpio: pinctrl@71070034 {
+                compatible = "mscc,ocelot-pinctrl";
+                gpio-controller;
+                #gpio-cells = <2>;
+                gpio-ranges = <&gpio 0 0 22>;
+                reg = <0x71070034>;
+
+                sgpio_pins: sgpio-pins {
+                    pins = "GPIO_0", "GPIO_1", "GPIO_2", "GPIO_3";
+                    function = "sg0";
+                };
+
+                miim1_pins: miim1-pins {
+                    pins = "GPIO_14", "GPIO_15";
+                    function = "miim";
+                };
+            };
+
+            sgpio: gpio@710700f8 {
+                compatible = "mscc,ocelot-sgpio";
+                #address-cells = <1>;
+                #size-cells = <0>;
+                bus-frequency = <12500000>;
+                clocks = <&ocelot_clock>;
+                microchip,sgpio-port-ranges = <0 15>;
+                pinctrl-names = "default";
+                pinctrl-0 = <&sgpio_pins>;
+                reg = <0x710700f8>;
+
+                sgpio_in0: gpio@0 {
+                    compatible = "microchip,sparx5-sgpio-bank";
+                    reg = <0>;
+                    gpio-controller;
+                    #gpio-cells = <3>;
+                    ngpios = <64>;
+                };
+
+                sgpio_out1: gpio@1 {
+                    compatible = "microchip,sparx5-sgpio-bank";
+                    reg = <1>;
+                    gpio-controller;
+                    #gpio-cells = <3>;
+                    ngpios = <64>;
+                };
+            };
+        };
+    };
+
+...
+
diff --git a/MAINTAINERS b/MAINTAINERS
index 91b4151c5ad1..119fb4207ba3 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -14355,6 +14355,7 @@ F:	tools/testing/selftests/drivers/net/ocelot/*
 OCELOT EXTERNAL SWITCH CONTROL
 M:	Colin Foster <colin.foster@in-advantage.com>
 S:	Supported
+F:	Documentation/devicetree/bindings/mfd/mscc,ocelot.yaml
 F:	include/linux/mfd/ocelot.h
 
 OCXL (Open Coherent Accelerator Processor Interface OpenCAPI) DRIVER
-- 
2.25.1

[PATCH v9 net-next 7/7] mfd: ocelot: add support for the vsc7512 chip via spi

[Colin Foster]

The VSC7512 is a networking chip that contains several peripherals. Many of
these peripherals are currently supported by the VSC7513 and VSC7514 chips,
but those run on an internal CPU. The VSC7512 lacks this CPU, and must be
controlled externally.

Utilize the existing drivers by referencing the chip as an MFD. Add support
for the two MDIO buses, the internal phys, pinctrl, and serial GPIO.

Signed-off-by: Colin Foster <colin.foster@in-advantage.com>
---
 MAINTAINERS                |   1 +
 drivers/mfd/Kconfig        |  18 +++
 drivers/mfd/Makefile       |   2 +
 drivers/mfd/ocelot-core.c  | 184 ++++++++++++++++++++++
 drivers/mfd/ocelot-spi.c   | 313 +++++++++++++++++++++++++++++++++++++
 drivers/mfd/ocelot.h       |  28 ++++
 include/linux/mfd/ocelot.h |  10 ++
 7 files changed, 556 insertions(+)
 create mode 100644 drivers/mfd/ocelot-core.c
 create mode 100644 drivers/mfd/ocelot-spi.c
 create mode 100644 drivers/mfd/ocelot.h

diff --git a/MAINTAINERS b/MAINTAINERS
index 119fb4207ba3..d24ec7c591a6 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -14356,6 +14356,7 @@ OCELOT EXTERNAL SWITCH CONTROL
 M:	Colin Foster <colin.foster@in-advantage.com>
 S:	Supported
 F:	Documentation/devicetree/bindings/mfd/mscc,ocelot.yaml
+F:	drivers/mfd/ocelot*
 F:	include/linux/mfd/ocelot.h
 
 OCXL (Open Coherent Accelerator Processor Interface OpenCAPI) DRIVER
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 3b59456f5545..6887b513b3fb 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -962,6 +962,24 @@ config MFD_MENF21BMC
 	  This driver can also be built as a module. If so the module
 	  will be called menf21bmc.
 
+config MFD_OCELOT
+	bool "Microsemi Ocelot External Control Support"
+	depends on SPI_MASTER
+	select MFD_CORE
+	select REGMAP_SPI
+	help
+	  Ocelot is a family of networking chips that support multiple ethernet
+	  and fibre interfaces. In addition to networking, they contain several
+	  other functions, including pictrl, MDIO, and communication with
+	  external chips. While some chips have an internal processor capable of
+	  running an OS, others don't. All chips can be controlled externally
+	  through different interfaces, including SPI, I2C, and PCIe.
+
+	  Say yes here to add support for Ocelot chips (VSC7511, VSC7512,
+	  VSC7513, VSC7514) controlled externally.
+
+	  If unsure, say N.
+
 config EZX_PCAP
 	bool "Motorola EZXPCAP Support"
 	depends on SPI_MASTER
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 858cacf659d6..bc517632ba5f 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -120,6 +120,8 @@ obj-$(CONFIG_MFD_MC13XXX_I2C)	+= mc13xxx-i2c.o
 
 obj-$(CONFIG_MFD_CORE)		+= mfd-core.o
 
+obj-$(CONFIG_MFD_OCELOT)	+= ocelot-core.o ocelot-spi.o
+
 obj-$(CONFIG_EZX_PCAP)		+= ezx-pcap.o
 obj-$(CONFIG_MFD_CPCAP)		+= motorola-cpcap.o
 
diff --git a/drivers/mfd/ocelot-core.c b/drivers/mfd/ocelot-core.c
new file mode 100644
index 000000000000..edc7698b6b1d
--- /dev/null
+++ b/drivers/mfd/ocelot-core.c
@@ -0,0 +1,184 @@
+// SPDX-License-Identifier: (GPL-2.0 OR MIT)
+/*
+ * Core driver for the Ocelot chip family.
+ *
+ * The VSC7511, 7512, 7513, and 7514 can be controlled internally via an
+ * on-chip MIPS processor, or externally via SPI, I2C, PCIe. This core driver is
+ * intended to be the bus-agnostic glue between, for example, the SPI bus and
+ * the child devices.
+ *
+ * Copyright 2021, 2022 Innovative Advantage Inc.
+ *
+ * Author: Colin Foster <colin.foster@in-advantage.com>
+ */
+
+#include <linux/mfd/core.h>
+#include <linux/mfd/ocelot.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <soc/mscc/ocelot.h>
+
+#include "ocelot.h"
+
+#define GCB_SOFT_RST			0x0008
+
+#define SOFT_CHIP_RST			0x1
+
+#define VSC7512_MIIM0_RES_START		0x7107009c
+#define VSC7512_MIIM0_RES_SIZE		0x24
+
+#define VSC7512_MIIM1_RES_START		0x710700c0
+#define VSC7512_MIIM1_RES_SIZE		0x24
+
+#define VSC7512_PHY_RES_START		0x710700f0
+#define VSC7512_PHY_RES_SIZE		0x4
+
+#define VSC7512_GPIO_RES_START		0x71070034
+#define VSC7512_GPIO_RES_SIZE		0x6c
+
+#define VSC7512_SIO_CTRL_RES_START	0x710700f8
+#define VSC7512_SIO_CTRL_RES_SIZE	0x100
+
+#define VSC7512_GCB_RST_SLEEP		100
+#define VSC7512_GCB_RST_TIMEOUT		100000
+
+static int ocelot_gcb_chip_rst_status(struct ocelot_ddata *ddata)
+{
+	int val, err;
+
+	err = regmap_read(ddata->gcb_regmap, GCB_SOFT_RST, &val);
+	if (err)
+		val = -1;
+
+	return val;
+}
+
+int ocelot_chip_reset(struct device *dev)
+{
+	struct ocelot_ddata *ddata = dev_get_drvdata(dev);
+	int ret, val;
+
+	/*
+	 * Reset the entire chip here to put it into a completely known state.
+	 * Other drivers may want to reset their own subsystems. The register
+	 * self-clears, so one write is all that is needed and wait for it to
+	 * clear.
+	 */
+	ret = regmap_write(ddata->gcb_regmap, GCB_SOFT_RST, SOFT_CHIP_RST);
+	if (ret)
+		return ret;
+
+	ret = readx_poll_timeout(ocelot_gcb_chip_rst_status, ddata, val, !val,
+				 VSC7512_GCB_RST_SLEEP,
+				 VSC7512_GCB_RST_TIMEOUT);
+	if (ret)
+		return dev_err_probe(ddata->dev, ret, "timeout: chip reset\n");
+
+	return 0;
+}
+EXPORT_SYMBOL_NS(ocelot_chip_reset, MFD_OCELOT);
+
+struct regmap *ocelot_init_regmap_from_resource(struct device *child,
+						const struct resource *res)
+{
+	struct device *dev = child->parent;
+
+	return ocelot_spi_init_regmap(dev, child, res);
+}
+EXPORT_SYMBOL_NS(ocelot_init_regmap_from_resource, MFD_OCELOT);
+
+static const struct resource vsc7512_miim0_resources[] = {
+	DEFINE_RES_REG_NAMED(VSC7512_MIIM0_RES_START, VSC7512_MIIM0_RES_SIZE,
+			     "gcb_miim0"),
+	DEFINE_RES_REG_NAMED(VSC7512_PHY_RES_START, VSC7512_PHY_RES_SIZE,
+			     "gcb_phy"),
+};
+
+static const struct resource vsc7512_miim1_resources[] = {
+	DEFINE_RES_REG_NAMED(VSC7512_MIIM1_RES_START, VSC7512_MIIM1_RES_SIZE,
+			     "gcb_miim1"),
+};
+
+static const struct resource vsc7512_pinctrl_resources[] = {
+	DEFINE_RES_REG_NAMED(VSC7512_GPIO_RES_START, VSC7512_GPIO_RES_SIZE,
+			     "gcb_gpio"),
+};
+
+static const struct resource vsc7512_sgpio_resources[] = {
+	DEFINE_RES_REG_NAMED(VSC7512_SIO_CTRL_RES_START,
+			     VSC7512_SIO_CTRL_RES_SIZE,
+			     "gcb_sio"),
+};
+
+static const struct mfd_cell vsc7512_devs[] = {
+	{
+		.name = "ocelot-pinctrl",
+		.of_compatible = "mscc,ocelot-pinctrl",
+		.num_resources = ARRAY_SIZE(vsc7512_pinctrl_resources),
+		.resources = vsc7512_pinctrl_resources,
+	}, {
+		.name = "ocelot-sgpio",
+		.of_compatible = "mscc,ocelot-sgpio",
+		.num_resources = ARRAY_SIZE(vsc7512_sgpio_resources),
+		.resources = vsc7512_sgpio_resources,
+	}, {
+		.name = "ocelot-miim0",
+		.of_compatible = "mscc,ocelot-miim",
+		.of_reg = vsc7512_miim0_resources[0].start,
+		.use_of_reg = true,
+		.num_resources = ARRAY_SIZE(vsc7512_miim0_resources),
+		.resources = vsc7512_miim0_resources,
+	}, {
+		.name = "ocelot-miim1",
+		.of_compatible = "mscc,ocelot-miim",
+		.num_resources = ARRAY_SIZE(vsc7512_miim1_resources),
+		.of_reg = vsc7512_miim1_resources[0].start,
+		.use_of_reg = true,
+		.resources = vsc7512_miim1_resources,
+	},
+};
+
+void
+ocelot_platform_init_regmap_from_resource(struct platform_device *pdev,
+					  unsigned int index,
+					  struct regmap **map,
+					  struct resource **res,
+					  const struct regmap_config *config)
+{
+	struct device *dev = &pdev->dev;
+	struct resource *resource;
+	struct resource **pres;
+	u32 __iomem *regs;
+
+	*map = ERR_PTR(ENODEV);
+	pres = res ? res : &resource;
+
+	regs = devm_platform_get_and_ioremap_resource(pdev, index, res);
+	if (IS_ERR(regs)) {
+		/*
+		 * Fall back to using IORESOURCE_REG, which is possible in an
+		 * MFD configuration
+		 */
+		*pres = platform_get_resource(pdev, IORESOURCE_REG, index);
+		if (!*pres) {
+			dev_err_probe(dev, PTR_ERR(*pres),
+				      "Failed to get resource\n");
+			return;
+		}
+
+		*map = ocelot_spi_init_regmap(dev->parent, dev, *pres);
+	} else {
+		*map = devm_regmap_init_mmio(dev, regs, config);
+	}
+}
+
+int ocelot_core_init(struct device *dev)
+{
+	return devm_mfd_add_devices(dev, PLATFORM_DEVID_AUTO, vsc7512_devs,
+				    ARRAY_SIZE(vsc7512_devs), NULL, 0, NULL);
+}
+EXPORT_SYMBOL_NS(ocelot_core_init, MFD_OCELOT);
+
+MODULE_DESCRIPTION("Externally Controlled Ocelot Chip Driver");
+MODULE_AUTHOR("Colin Foster <colin.foster@in-advantage.com>");
+MODULE_LICENSE("GPL");
diff --git a/drivers/mfd/ocelot-spi.c b/drivers/mfd/ocelot-spi.c
new file mode 100644
index 000000000000..e07dc1d040a8
--- /dev/null
+++ b/drivers/mfd/ocelot-spi.c
@@ -0,0 +1,313 @@
+// SPDX-License-Identifier: (GPL-2.0 OR MIT)
+/*
+ * SPI core driver for the Ocelot chip family.
+ *
+ * This driver will handle everything necessary to allow for communication over
+ * SPI to the VSC7511, VSC7512, VSC7513 and VSC7514 chips. The main functions
+ * are to prepare the chip's SPI interface for a specific bus speed, and a host
+ * processor's endianness. This will create and distribute regmaps for any
+ * children.
+ *
+ * Copyright 2021, 2022 Innovative Advantage Inc.
+ *
+ * Author: Colin Foster <colin.foster@in-advantage.com>
+ */
+
+#include <linux/iopoll.h>
+#include <linux/kconfig.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/spi/spi.h>
+
+#include <asm/byteorder.h>
+
+#include "ocelot.h"
+
+#define DEV_CPUORG_IF_CTRL		0x0000
+#define DEV_CPUORG_IF_CFGSTAT		0x0004
+
+#define CFGSTAT_IF_NUM_VCORE		(0 << 24)
+#define CFGSTAT_IF_NUM_VRAP		(1 << 24)
+#define CFGSTAT_IF_NUM_SI		(2 << 24)
+#define CFGSTAT_IF_NUM_MIIM		(3 << 24)
+
+#define VSC7512_DEVCPU_ORG_RES_START	0x71000000
+#define VSC7512_DEVCPU_ORG_RES_SIZE	0x38
+
+#define VSC7512_CHIP_REGS_RES_START	0x71070000
+#define VSC7512_CHIP_REGS_RES_SIZE	0x14
+
+static const struct resource vsc7512_dev_cpuorg_resource =
+	DEFINE_RES_REG_NAMED(VSC7512_DEVCPU_ORG_RES_START,
+			     VSC7512_DEVCPU_ORG_RES_SIZE,
+			     "devcpu_org");
+
+static const struct resource vsc7512_gcb_resource =
+	DEFINE_RES_REG_NAMED(VSC7512_CHIP_REGS_RES_START,
+			     VSC7512_CHIP_REGS_RES_SIZE,
+			     "devcpu_gcb_chip_regs");
+
+static int ocelot_spi_initialize(struct device *dev)
+{
+	struct ocelot_ddata *ddata = dev_get_drvdata(dev);
+	u32 val, check;
+	int err;
+
+	val = OCELOT_SPI_BYTE_ORDER;
+
+	/*
+	 * The SPI address must be big-endian, but we want the payload to match
+	 * our CPU. These are two bits (0 and 1) but they're repeated such that
+	 * the write from any configuration will be valid. The four
+	 * configurations are:
+	 *
+	 * 0b00: little-endian, MSB first
+	 * |            111111   | 22221111 | 33222222 |
+	 * | 76543210 | 54321098 | 32109876 | 10987654 |
+	 *
+	 * 0b01: big-endian, MSB first
+	 * | 33222222 | 22221111 | 111111   |          |
+	 * | 10987654 | 32109876 | 54321098 | 76543210 |
+	 *
+	 * 0b10: little-endian, LSB first
+	 * |              111111 | 11112222 | 22222233 |
+	 * | 01234567 | 89012345 | 67890123 | 45678901 |
+	 *
+	 * 0b11: big-endian, LSB first
+	 * | 22222233 | 11112222 |   111111 |          |
+	 * | 45678901 | 67890123 | 89012345 | 01234567 |
+	 */
+	err = regmap_write(ddata->cpuorg_regmap, DEV_CPUORG_IF_CTRL, val);
+	if (err)
+		return err;
+
+	/*
+	 * Apply the number of padding bytes between a read request and the data
+	 * payload. Some registers have access times of up to 1us, so if the
+	 * first payload bit is shifted out too quickly, the read will fail.
+	 */
+	val = ddata->spi_padding_bytes;
+	err = regmap_write(ddata->cpuorg_regmap, DEV_CPUORG_IF_CFGSTAT, val);
+	if (err)
+		return err;
+
+	/*
+	 * After we write the interface configuration, read it back here. This
+	 * will verify several different things. The first is that the number of
+	 * padding bytes actually got written correctly. These are found in bits
+	 * 0:3.
+	 *
+	 * The second is that bit 16 is cleared. Bit 16 is IF_CFGSTAT:IF_STAT,
+	 * and will be set if the register access is too fast. This would be in
+	 * the condition that the number of padding bytes is insufficient for
+	 * the SPI bus frequency.
+	 *
+	 * The last check is for bits 31:24, which define the interface by which
+	 * the registers are being accessed. Since we're accessing them via the
+	 * serial interface, it must return IF_NUM_SI.
+	 */
+	check = val | CFGSTAT_IF_NUM_SI;
+
+	err = regmap_read(ddata->cpuorg_regmap, DEV_CPUORG_IF_CFGSTAT, &val);
+	if (err)
+		return err;
+
+	if (check != val)
+		return -ENODEV;
+
+	return 0;
+}
+
+static const struct regmap_config ocelot_spi_regmap_config = {
+	.reg_bits = 24,
+	.reg_stride = 4,
+	.reg_downshift = 2,
+	.val_bits = 32,
+
+	.write_flag_mask = 0x80,
+
+	.use_single_write = true,
+	.can_multi_write = false,
+
+	.reg_format_endian = REGMAP_ENDIAN_BIG,
+	.val_format_endian = REGMAP_ENDIAN_NATIVE,
+};
+
+static int ocelot_spi_regmap_bus_read(void *context,
+				      const void *reg, size_t reg_size,
+				      void *val, size_t val_size)
+{
+	struct ocelot_ddata *ddata = context;
+	static const u8 dummy_buf[16] = {0};
+	struct spi_transfer tx, padding, rx;
+	struct spi_device *spi = ddata->spi;
+	struct spi_message msg;
+
+	spi = ddata->spi;
+
+	spi_message_init(&msg);
+
+	memset(&tx, 0, sizeof(tx));
+
+	tx.tx_buf = reg;
+	tx.len = reg_size;
+
+	spi_message_add_tail(&tx, &msg);
+
+	if (ddata->spi_padding_bytes) {
+		memset(&padding, 0, sizeof(padding));
+
+		padding.len = ddata->spi_padding_bytes;
+		padding.tx_buf = dummy_buf;
+		padding.dummy_data = 1;
+
+		spi_message_add_tail(&padding, &msg);
+	}
+
+	memset(&rx, 0, sizeof(rx));
+	rx.rx_buf = val;
+	rx.len = val_size;
+
+	spi_message_add_tail(&rx, &msg);
+
+	return spi_sync(spi, &msg);
+}
+
+static int ocelot_spi_regmap_bus_write(void *context, const void *data,
+				       size_t count)
+{
+	struct ocelot_ddata *ddata = context;
+	struct spi_device *spi = ddata->spi;
+
+	return spi_write(spi, data, count);
+}
+
+static const struct regmap_bus ocelot_spi_regmap_bus = {
+	.write = ocelot_spi_regmap_bus_write,
+	.read = ocelot_spi_regmap_bus_read,
+};
+
+struct regmap *
+ocelot_spi_init_regmap(struct device *dev, struct device *child,
+		       const struct resource *res)
+{
+	struct ocelot_ddata *ddata = dev_get_drvdata(dev);
+	struct regmap_config regmap_config;
+
+	memcpy(&regmap_config, &ocelot_spi_regmap_config,
+	       sizeof(regmap_config));
+
+	regmap_config.name = res->name;
+	regmap_config.max_register = res->end - res->start;
+	regmap_config.reg_base = res->start;
+
+	return devm_regmap_init(child, &ocelot_spi_regmap_bus, ddata,
+				&regmap_config);
+}
+
+static int ocelot_spi_probe(struct spi_device *spi)
+{
+	struct device *dev = &spi->dev;
+	struct ocelot_ddata *ddata;
+	struct regmap *r;
+	int err;
+
+	ddata = devm_kzalloc(dev, sizeof(*ddata), GFP_KERNEL);
+	if (!ddata)
+		return -ENOMEM;
+
+	ddata->dev = dev;
+	dev_set_drvdata(dev, ddata);
+
+	if (spi->max_speed_hz <= 500000) {
+		ddata->spi_padding_bytes = 0;
+	} else {
+		/*
+		 * Calculation taken from the manual for IF_CFGSTAT:IF_CFG.
+		 * Register access time is 1us, so we need to configure and send
+		 * out enough padding bytes between the read request and data
+		 * transmission that lasts at least 1 microsecond.
+		 */
+		ddata->spi_padding_bytes = 1 +
+			(spi->max_speed_hz / 1000000 + 2) / 8;
+	}
+
+	ddata->spi = spi;
+
+	spi->bits_per_word = 8;
+
+	err = spi_setup(spi);
+	if (err < 0) {
+		return dev_err_probe(&spi->dev, err,
+				     "Error performing SPI setup\n");
+	}
+
+	r = ocelot_spi_init_regmap(dev, dev, &vsc7512_dev_cpuorg_resource);
+	if (IS_ERR(r))
+		return PTR_ERR(r);
+
+	ddata->cpuorg_regmap = r;
+
+	r = ocelot_spi_init_regmap(dev, dev, &vsc7512_gcb_resource);
+	if (IS_ERR(r))
+		return PTR_ERR(r);
+
+	ddata->gcb_regmap = r;
+
+	/*
+	 * The chip must be set up for SPI before it gets initialized and reset.
+	 * This must be done before calling init, and after a chip reset is
+	 * performed.
+	 */
+	err = ocelot_spi_initialize(dev);
+	if (err)
+		return dev_err_probe(dev, err, "Error initializing SPI bus\n");
+
+	err = ocelot_chip_reset(dev);
+	if (err)
+		return dev_err_probe(dev, err, "Error resetting device\n");
+
+	/*
+	 * A chip reset will clear the SPI configuration, so it needs to be done
+	 * again before we can access any registers
+	 */
+	err = ocelot_spi_initialize(dev);
+	if (err) {
+		return dev_err_probe(dev, err,
+				     "Error initializing SPI bus after reset\n");
+	}
+
+	err = ocelot_core_init(dev);
+	if (err < 0) {
+		return dev_err_probe(dev, err,
+				     "Error initializing Ocelot core\n");
+		return err;
+	}
+
+	return 0;
+}
+
+static const struct spi_device_id ocelot_spi_ids[] = {
+	{ "vsc7512", 0 },
+	{ }
+};
+
+static const struct of_device_id ocelot_spi_of_match[] = {
+	{ .compatible = "mscc,vsc7512-spi" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ocelot_spi_of_match);
+
+static struct spi_driver ocelot_spi_driver = {
+	.driver = {
+		.name = "ocelot_spi",
+		.of_match_table = ocelot_spi_of_match,
+	},
+	.id_table = ocelot_spi_ids,
+	.probe = ocelot_spi_probe,
+};
+module_spi_driver(ocelot_spi_driver);
+
+MODULE_DESCRIPTION("SPI Controlled Ocelot Chip Driver");
+MODULE_AUTHOR("Colin Foster <colin.foster@in-advantage.com>");
+MODULE_LICENSE("Dual MIT/GPL");
diff --git a/drivers/mfd/ocelot.h b/drivers/mfd/ocelot.h
new file mode 100644
index 000000000000..cf33c3ab89c2
--- /dev/null
+++ b/drivers/mfd/ocelot.h
@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: GPL-2.0 OR MIT */
+/* Copyright 2021, 2022 Innovative Advantage Inc. */
+
+#include <asm/byteorder.h>
+
+struct ocelot_ddata {
+	struct device *dev;
+	struct regmap *gcb_regmap;
+	struct regmap *cpuorg_regmap;
+	int spi_padding_bytes;
+	struct spi_device *spi;
+};
+
+int ocelot_chip_reset(struct device *dev);
+int ocelot_core_init(struct device *dev);
+
+/* SPI-specific routines that won't be necessary for other interfaces */
+struct regmap *ocelot_spi_init_regmap(struct device *dev, struct device *child,
+				      const struct resource *res);
+
+#define OCELOT_SPI_BYTE_ORDER_LE 0x00000000
+#define OCELOT_SPI_BYTE_ORDER_BE 0x81818181
+
+#ifdef __LITTLE_ENDIAN
+#define OCELOT_SPI_BYTE_ORDER OCELOT_SPI_BYTE_ORDER_LE
+#else
+#define OCELOT_SPI_BYTE_ORDER OCELOT_SPI_BYTE_ORDER_BE
+#endif
diff --git a/include/linux/mfd/ocelot.h b/include/linux/mfd/ocelot.h
index 40e775f1143f..624879e89f5a 100644
--- a/include/linux/mfd/ocelot.h
+++ b/include/linux/mfd/ocelot.h
@@ -2,9 +2,18 @@
 /* Copyright 2022 Innovative Advantage Inc. */
 
 #include <linux/err.h>
+#include <linux/kconfig.h>
 #include <linux/platform_device.h>
 #include <linux/regmap.h>
 
+#if IS_ENABLED(CONFIG_MFD_OCELOT)
+void
+ocelot_platform_init_regmap_from_resource(struct platform_device *pdev,
+					  unsigned int index,
+					  struct regmap **map,
+					  struct resource **res,
+					  const struct regmap_config *config);
+#else
 static inline void
 ocelot_platform_init_regmap_from_resource(struct platform_device *pdev,
 					  unsigned int index,
@@ -20,3 +29,4 @@ ocelot_platform_init_regmap_from_resource(struct platform_device *pdev,
 	else
 		*map = ERR_PTR(ENODEV);
 }
+#endif
-- 
2.25.1

Re: [PATCH v9 net-next 7/7] mfd: ocelot: add support for the vsc7512 chip via spi

[kernel test robot]

Hi Colin,

I love your patch! Perhaps something to improve:

[auto build test WARNING on net-next/master]

url:    https://github.com/intel-lab-lkp/linux/commits/Colin-Foster/add-support-for-VSC7512-control-over-SPI/20220611-015854
base:   https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git 7defbc9aed2b1fdf21586b78e085c468fd95a2d1
config: arc-allyesconfig (https://download.01.org/0day-ci/archive/20220611/202206110358.2hO4gzbU-lkp@intel.com/config)
compiler: arceb-elf-gcc (GCC) 11.3.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/intel-lab-lkp/linux/commit/be13bccb3f0b376d8d189aa8d14e5b461701f4db
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Colin-Foster/add-support-for-VSC7512-control-over-SPI/20220611-015854
        git checkout be13bccb3f0b376d8d189aa8d14e5b461701f4db
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.3.0 make.cross W=1 O=build_dir ARCH=arc SHELL=/bin/bash drivers/mfd/

If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

>> drivers/mfd/ocelot-core.c:81:16: warning: no previous prototype for 'ocelot_init_regmap_from_resource' [-Wmissing-prototypes]
      81 | struct regmap *ocelot_init_regmap_from_resource(struct device *child,
         |                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


vim +/ocelot_init_regmap_from_resource +81 drivers/mfd/ocelot-core.c

    80	
  > 81	struct regmap *ocelot_init_regmap_from_resource(struct device *child,
    82							const struct resource *res)
    83	{
    84		struct device *dev = child->parent;
    85	
    86		return ocelot_spi_init_regmap(dev, child, res);
    87	}
    88	EXPORT_SYMBOL_NS(ocelot_init_regmap_from_resource, MFD_OCELOT);
    89	

-- 
0-DAY CI Kernel Test Service
https://01.org/lkp

Re: [PATCH v9 net-next 1/7] mfd: ocelot: add helper to get regmap from a resource

[Andy Shevchenko]

On Fri, Jun 10, 2022 at 7:57 PM Colin Foster
<colin.foster@in-advantage.com> wrote:
>
> Several ocelot-related modules are designed for MMIO / regmaps. As such,
> they often use a combination of devm_platform_get_and_ioremap_resource and
> devm_regmap_init_mmio.
>
> Operating in an MFD might be different, in that it could be memory mapped,
> or it could be SPI, I2C... In these cases a fallback to use IORESOURCE_REG
> instead of IORESOURCE_MEM becomes necessary.
>
> When this happens, there's redundant logic that needs to be implemented in
> every driver. In order to avoid this redundancy, utilize a single function
> that, if the MFD scenario is enabled, will perform this fallback logic.

...

> +#include <linux/err.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>

Since it's header the rule of thumb is to include headers this one is
a direct user of. Here I see missed
types.h

Also missed forward declarations

struct resource;

...

> +       if (!IS_ERR(regs))

Why not positive conditional?

> +               *map = devm_regmap_init_mmio(&pdev->dev, regs, config);
> +       else
> +               *map = ERR_PTR(ENODEV);

Missed -.

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v9 net-next 2/7] net: mdio: mscc-miim: add ability to be used in a non-mmio configuration

[Andy Shevchenko]

On Fri, Jun 10, 2022 at 7:57 PM Colin Foster
<colin.foster@in-advantage.com> wrote:
>
> There are a few Ocelot chips that contain the logic for this bus, but are
> controlled externally. Specifically the VSC7511, 7512, 7513, and 7514. In
> the externally controlled configurations these registers are not
> memory-mapped.
>
> Add support for these non-memory-mapped configurations.

...

> +       ocelot_platform_init_regmap_from_resource(pdev, 0, &mii_regmap, NULL,
> +                                                 &mscc_miim_regmap_config);

This is a bit non-standard, why not to follow the previously used API
design, i.e.

mii_regmap.map = ...

?

...

> +       ocelot_platform_init_regmap_from_resource(pdev, 1, &phy_regmap, &res,
> +                                                 &mscc_miim_phy_regmap_config);

Ditto.

Also here is the question how '_from_'  is aligned with '&res'. If
it's _from_ a resource then the resource is already a pointer.

...

>         if (res) {
> -               phy_regs = devm_ioremap_resource(dev, res);
> -               if (IS_ERR(phy_regs)) {
> -                       dev_err(dev, "Unable to map internal phy registers\n");
> -                       return PTR_ERR(phy_regs);
> -               }
> -
> -               phy_regmap = devm_regmap_init_mmio(dev, phy_regs,
> -                                                  &mscc_miim_phy_regmap_config);
>                 if (IS_ERR(phy_regmap)) {
>                         dev_err(dev, "Unable to create phy register regmap\n");
>                         return PTR_ERR(phy_regmap);
>                 }

This looks weird. You check an error here instead of the API you
called. It's a weird design, the rationale of which is doubtful and
has to be at least explained.

> +       } else {
> +               phy_regmap = NULL;
>         }

--
With Best Regards,
Andy Shevchenko

Re: [PATCH v9 net-next 1/7] mfd: ocelot: add helper to get regmap from a resource

[Colin Foster]

On Sat, Jun 11, 2022 at 12:26:31PM +0200, Andy Shevchenko wrote:
> On Fri, Jun 10, 2022 at 7:57 PM Colin Foster
> <colin.foster@in-advantage.com> wrote:
> >
> > Several ocelot-related modules are designed for MMIO / regmaps. As such,
> > they often use a combination of devm_platform_get_and_ioremap_resource and
> > devm_regmap_init_mmio.
> >
> > Operating in an MFD might be different, in that it could be memory mapped,
> > or it could be SPI, I2C... In these cases a fallback to use IORESOURCE_REG
> > instead of IORESOURCE_MEM becomes necessary.
> >
> > When this happens, there's redundant logic that needs to be implemented in
> > every driver. In order to avoid this redundancy, utilize a single function
> > that, if the MFD scenario is enabled, will perform this fallback logic.
> 
> ...
> 
> > +#include <linux/err.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/regmap.h>
> 
> Since it's header the rule of thumb is to include headers this one is
> a direct user of. Here I see missed
> types.h
> 
> Also missed forward declarations
> 
> struct resource;

Ahh, thank you. Yes, you mentioned this in v8 but I misuderstood what
you were saying. I'll also include types.h.

> 
> ...
> 
> > +       if (!IS_ERR(regs))
> 
> Why not positive conditional?
> 
> > +               *map = devm_regmap_init_mmio(&pdev->dev, regs, config);
> > +       else
> > +               *map = ERR_PTR(ENODEV);
> 
> Missed -.

Fixed. Thanks.

> 
> -- 
> With Best Regards,
> Andy Shevchenko

Re: [PATCH v9 net-next 2/7] net: mdio: mscc-miim: add ability to be used in a non-mmio configuration

[Colin Foster]

Hi Andy,

On Sat, Jun 11, 2022 at 12:34:59PM +0200, Andy Shevchenko wrote:
> On Fri, Jun 10, 2022 at 7:57 PM Colin Foster
> <colin.foster@in-advantage.com> wrote:
> >
> > There are a few Ocelot chips that contain the logic for this bus, but are
> > controlled externally. Specifically the VSC7511, 7512, 7513, and 7514. In
> > the externally controlled configurations these registers are not
> > memory-mapped.
> >
> > Add support for these non-memory-mapped configurations.
> 
> ...
> 
> > +       ocelot_platform_init_regmap_from_resource(pdev, 0, &mii_regmap, NULL,
> > +                                                 &mscc_miim_regmap_config);
> 
> This is a bit non-standard, why not to follow the previously used API
> design, i.e.
> 
> mii_regmap.map = ...
> 
> ?

I see your point. It looks like there's no reason to pass in &mii_regmap
and it can just be returned.

> 
> ...
> 
> > +       ocelot_platform_init_regmap_from_resource(pdev, 1, &phy_regmap, &res,
> > +                                                 &mscc_miim_phy_regmap_config);
> 
> Ditto.
> 
> Also here is the question how '_from_'  is aligned with '&res'. If
> it's _from_ a resource then the resource is already a pointer.

Yes, this is probably worth a second look. During v8 you noted that I
was repeating a lot of the same logic across several files, so I created
ocelot_platform_init_regmap_from_resource.

The "gotcha" is while most of those scenarios have a required resource,
the phy_regmap is optional - so a scenario where the resource doesn't
exist could be considered valid.

Would it make sense to make the init_regmap_from_resource function
return ERR_PTR(-ENOENT) if regs doesn't exist? That would clean up the
API quite a bit:

phy_regmap = ocelot_platform_init_regmap_from_resource(pdev, 1,
                                                       &map_config);
if (IS_ERR(phy_regmap) && phy_regmap != -ENOENT) {
        dev_err(); ...
}

It looks like none of the two functions that would get returned
otherwise (devm_regmap_init or devm_regmap_init_mmio) would return that
value...

> 
> ...
> 
> >         if (res) {
> > -               phy_regs = devm_ioremap_resource(dev, res);
> > -               if (IS_ERR(phy_regs)) {
> > -                       dev_err(dev, "Unable to map internal phy registers\n");
> > -                       return PTR_ERR(phy_regs);
> > -               }
> > -
> > -               phy_regmap = devm_regmap_init_mmio(dev, phy_regs,
> > -                                                  &mscc_miim_phy_regmap_config);
> >                 if (IS_ERR(phy_regmap)) {
> >                         dev_err(dev, "Unable to create phy register regmap\n");
> >                         return PTR_ERR(phy_regmap);
> >                 }
> 
> This looks weird. You check an error here instead of the API you
> called. It's a weird design, the rationale of which is doubtful and
> has to be at least explained.

I agree. With the changes I'm suggesting above this block of code would
become:

if (IS_ERR(phy_regmap)) {
        if (phy_regmap == -ENOENT) {
                phy_regmap = NULL;
        } else {
                dev_err(dev, "...");
                return PTR_ERR(phy_regmap);
        }
}

That seems easier to follow than the if(res) block...


Thanks for the feedback!

> 
> > +       } else {
> > +               phy_regmap = NULL;
> >         }
> 
> --
> With Best Regards,
> Andy Shevchenko