Merge tag 'gpio-v5.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio

Pull GPIO updates from Linus Walleij:
 "This is the bulk of GPIO changes for the v5.8 kernel cycle.

  Core changes:

   - A new GPIO aggregator driver has been merged: this can join a few
     select GPIO lines into a new aggregated GPIO chip. This can be used
     for security: a process can be granted access to only these lines,
     for example for industrial control. Another way to use this is to
     reexpose certain select lines to a virtual machine or container.

   - Warn if the gpio-line-names is too long in he DT parser core.

   - GPIO lines can now be looked up by line name in addition to being
     looked up by offset.

  New drivers:

   - A new generic regmap GPIO driver has been merged. Too many regmap
     drivers are starting to look like each other so we need to create
     some common ground and try to move drivers over to using that.

   - The F7188X driver now supports F81865.

  Driver improvements:

   - Large improvements to the PCA953x expander, get multiple lines and
     several cleanups.

   - Large improvements to the DesignWare DWAPB driver, and Sergey Semin
     has volunteered to maintain it.

   - PL061 can now be built as a module, this is part of a bigger effort
     to make the ARM platforms more modular"

* tag 'gpio-v5.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (77 commits)
  gpio: pca953x: Drop unneeded ACPI_PTR()
  MAINTAINERS: Add gpio regmap section
  gpio: add a reusable generic gpio_chip using regmap
  gpiolib: Introduce gpiochip_irqchip_add_domain()
  gpio: gpiolib: Allow GPIO IRQs to lazy disable
  gpiolib: Separate GPIO_GET_LINEINFO_WATCH_IOCTL conditional
  gpio: rcar: Fix runtime PM imbalance on error
  gpio: pca935x: Allow IRQ support for driver built as a module
  gpio: pxa: Add COMPILE_TEST support
  dt-bindings: gpio: Add renesas,em-gio bindings
  MAINTAINERS: Fix file name for DesignWare GPIO DT schema
  gpio: dwapb: Remove unneeded has_irq member in struct dwapb_port_property
  gpio: dwapb: Don't use IRQ 0 as valid Linux interrupt
  gpio: dwapb: avoid error message for optional IRQ
  gpio: dwapb: Call acpi_gpiochip_free_interrupts() on GPIO chip de-registration
  gpio: max730x: bring gpiochip_add_data after port config
  MAINTAINERS: Add GPIO Aggregator section
  docs: gpio: Add GPIO Aggregator documentation
  gpio: Add GPIO Aggregator
  gpiolib: Add support for GPIO lookup by line name
  ...

6 files changed, 326 insertions, 70 deletions

diff --git a/Documentation/admin-guide/gpio/gpio-aggregator.rst b/Documentation/admin-guide/gpio/gpio-aggregator.rst
new file mode 100644
index 000000000000..5cd1e7221756
--- /dev/null
+++ b/Documentation/admin-guide/gpio/gpio-aggregator.rst
@@ -0,0 +1,111 @@
+.. SPDX-License-Identifier: GPL-2.0-only
+
+GPIO Aggregator
+===============
+
+The GPIO Aggregator provides a mechanism to aggregate GPIOs, and expose them as
+a new gpio_chip.  This supports the following use cases.
+
+
+Aggregating GPIOs using Sysfs
+-----------------------------
+
+GPIO controllers are exported to userspace using /dev/gpiochip* character
+devices.  Access control to these devices is provided by standard UNIX file
+system permissions, on an all-or-nothing basis: either a GPIO controller is
+accessible for a user, or it is not.
+
+The GPIO Aggregator provides access control for a set of one or more GPIOs, by
+aggregating them into a new gpio_chip, which can be assigned to a group or user
+using standard UNIX file ownership and permissions.  Furthermore, this
+simplifies and hardens exporting GPIOs to a virtual machine, as the VM can just
+grab the full GPIO controller, and no longer needs to care about which GPIOs to
+grab and which not, reducing the attack surface.
+
+Aggregated GPIO controllers are instantiated and destroyed by writing to
+write-only attribute files in sysfs.
+
+    /sys/bus/platform/drivers/gpio-aggregator/
+
+	"new_device" ...
+		Userspace may ask the kernel to instantiate an aggregated GPIO
+		controller by writing a string describing the GPIOs to
+		aggregate to the "new_device" file, using the format
+
+		.. code-block:: none
+
+		    [<gpioA>] [<gpiochipB> <offsets>] ...
+
+		Where:
+
+		    "<gpioA>" ...
+			    is a GPIO line name,
+
+		    "<gpiochipB>" ...
+			    is a GPIO chip label, and
+
+		    "<offsets>" ...
+			    is a comma-separated list of GPIO offsets and/or
+			    GPIO offset ranges denoted by dashes.
+
+		Example: Instantiate a new GPIO aggregator by aggregating GPIO
+		line 19 of "e6052000.gpio" and GPIO lines 20-21 of
+		"e6050000.gpio" into a new gpio_chip:
+
+		.. code-block:: sh
+
+		    $ echo 'e6052000.gpio 19 e6050000.gpio 20-21' > new_device
+
+	"delete_device" ...
+		Userspace may ask the kernel to destroy an aggregated GPIO
+		controller after use by writing its device name to the
+		"delete_device" file.
+
+		Example: Destroy the previously-created aggregated GPIO
+		controller, assumed to be "gpio-aggregator.0":
+
+		.. code-block:: sh
+
+		    $ echo gpio-aggregator.0 > delete_device
+
+
+Generic GPIO Driver
+-------------------
+
+The GPIO Aggregator can also be used as a generic driver for a simple
+GPIO-operated device described in DT, without a dedicated in-kernel driver.
+This is useful in industrial control, and is not unlike e.g. spidev, which
+allows the user to communicate with an SPI device from userspace.
+
+Binding a device to the GPIO Aggregator is performed either by modifying the
+gpio-aggregator driver, or by writing to the "driver_override" file in Sysfs.
+
+Example: If "door" is a GPIO-operated device described in DT, using its own
+compatible value::
+
+	door {
+		compatible = "myvendor,mydoor";
+
+		gpios = <&gpio2 19 GPIO_ACTIVE_HIGH>,
+			<&gpio2 20 GPIO_ACTIVE_LOW>;
+		gpio-line-names = "open", "lock";
+	};
+
+it can be bound to the GPIO Aggregator by either:
+
+1. Adding its compatible value to ``gpio_aggregator_dt_ids[]``,
+2. Binding manually using "driver_override":
+
+.. code-block:: sh
+
+    $ echo gpio-aggregator > /sys/bus/platform/devices/door/driver_override
+    $ echo door > /sys/bus/platform/drivers/gpio-aggregator/bind
+
+After that, a new gpiochip "door" has been created:
+
+.. code-block:: sh
+
+    $ gpioinfo door
+    gpiochip12 - 2 lines:
+	    line   0:       "open"       unused   input  active-high
+	    line   1:       "lock"       unused   input  active-high
diff --git a/Documentation/admin-guide/gpio/index.rst b/Documentation/admin-guide/gpio/index.rst
index a244ba4e87d5..ef2838638e96 100644
--- a/Documentation/admin-guide/gpio/index.rst
+++ b/Documentation/admin-guide/gpio/index.rst
@@ -7,6 +7,7 @@ gpio
 .. toctree::
     :maxdepth: 1
 
+    gpio-aggregator
     sysfs
 
 .. only::  subproject and html
diff --git a/Documentation/devicetree/bindings/gpio/renesas,em-gio.yaml b/Documentation/devicetree/bindings/gpio/renesas,em-gio.yaml
new file mode 100644
index 000000000000..8bdef812c87c
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/renesas,em-gio.yaml
@@ -0,0 +1,70 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/gpio/renesas,em-gio.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Renesas EMMA Mobile General Purpose I/O Interface
+
+maintainers:
+  - Magnus Damm <magnus.damm@gmail.com>
+
+properties:
+  compatible:
+    const: renesas,em-gio
+
+  reg:
+    items:
+      - description: First set of contiguous registers
+      - description: Second set of contiguous registers
+
+  interrupts:
+    items:
+      - description: Interrupt for the first set of 16 GPIO ports
+      - description: Interrupt for the second set of 16 GPIO ports
+
+  gpio-controller: true
+
+  '#gpio-cells':
+    const: 2
+
+  gpio-ranges:
+    maxItems: 1
+
+  ngpios:
+    minimum: 1
+    maximum: 32
+
+  interrupt-controller: true
+
+  '#interrupt-cells':
+    const: 2
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - gpio-controller
+  - '#gpio-cells'
+  - gpio-ranges
+  - ngpios
+  - interrupt-controller
+  - '#interrupt-cells'
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    gpio0: gpio@e0050000 {
+            compatible = "renesas,em-gio";
+            reg = <0xe0050000 0x2c>, <0xe0050040 0x20>;
+            interrupts = <GIC_SPI 67 IRQ_TYPE_LEVEL_HIGH>,
+                         <GIC_SPI 68 IRQ_TYPE_LEVEL_HIGH>;
+            gpio-controller;
+            #gpio-cells = <2>;
+            gpio-ranges = <&pfc 0 0 32>;
+            ngpios = <32>;
+            interrupt-controller;
+            #interrupt-cells = <2>;
+    };
diff --git a/Documentation/devicetree/bindings/gpio/snps,dw-apb-gpio.yaml b/Documentation/devicetree/bindings/gpio/snps,dw-apb-gpio.yaml
new file mode 100644
index 000000000000..04a3c51e1dc1
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/snps,dw-apb-gpio.yaml
@@ -0,0 +1,134 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/gpio/snps,dw-apb-gpio.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Synopsys DesignWare APB GPIO controller
+
+description: |
+  Synopsys DesignWare GPIO controllers have a configurable number of ports,
+  each of which are intended to be represented as child nodes with the generic
+  GPIO-controller properties as desribed in this bindings file.
+
+maintainers:
+  - Hoan Tran <hoan@os.amperecomputing.com>
+  - Serge Semin <fancer.lancer@gmail.com>
+
+properties:
+  $nodename:
+    pattern: "^gpio@[0-9a-f]+$"
+
+  compatible:
+    const: snps,dw-apb-gpio
+
+  "#address-cells":
+    const: 1
+
+  "#size-cells":
+    const: 0
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    minItems: 1
+    items:
+      - description: APB interface clock source
+      - description: DW GPIO debounce reference clock source
+
+  clock-names:
+    minItems: 1
+    items:
+      - const: bus
+      - const: db
+
+  resets:
+    maxItems: 1
+
+patternProperties:
+  "^gpio-(port|controller)@[0-9a-f]+$":
+    type: object
+    properties:
+      compatible:
+        const: snps,dw-apb-gpio-port
+
+      reg:
+        maxItems: 1
+
+      gpio-controller: true
+
+      '#gpio-cells':
+        const: 2
+
+      snps,nr-gpios:
+        description: The number of GPIO pins exported by the port.
+        default: 32
+        allOf:
+          - $ref: /schemas/types.yaml#/definitions/uint32
+          - minimum: 1
+            maximum: 32
+
+      interrupts:
+        description: |
+          The interrupts to the parent controller raised when GPIOs generate
+          the interrupts. If the controller provides one combined interrupt
+          for all GPIOs, specify a single interrupt. If the controller provides
+          one interrupt for each GPIO, provide a list of interrupts that
+          correspond to each of the GPIO pins.
+        minItems: 1
+        maxItems: 32
+
+      interrupt-controller: true
+
+      '#interrupt-cells':
+        const: 2
+
+    required:
+      - compatible
+      - reg
+      - gpio-controller
+      - '#gpio-cells'
+
+    dependencies:
+      interrupt-controller: [ interrupts ]
+
+    additionalProperties: false
+
+additionalProperties: false
+
+required:
+  - compatible
+  - reg
+  - "#address-cells"
+  - "#size-cells"
+
+examples:
+  - |
+    gpio: gpio@20000 {
+      compatible = "snps,dw-apb-gpio";
+      reg = <0x20000 0x1000>;
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      porta: gpio-port@0 {
+        compatible = "snps,dw-apb-gpio-port";
+        reg = <0>;
+        gpio-controller;
+        #gpio-cells = <2>;
+        snps,nr-gpios = <8>;
+        interrupt-controller;
+        #interrupt-cells = <2>;
+        interrupt-parent = <&vic1>;
+        interrupts = <0>;
+      };
+
+      portb: gpio-port@1 {
+        compatible = "snps,dw-apb-gpio-port";
+        reg = <1>;
+        gpio-controller;
+        #gpio-cells = <2>;
+        snps,nr-gpios = <8>;
+      };
+    };
+...
diff --git a/Documentation/devicetree/bindings/gpio/snps-dwapb-gpio.txt b/Documentation/devicetree/bindings/gpio/snps-dwapb-gpio.txt
deleted file mode 100644
index 839dd32ffe11..000000000000
--- a/Documentation/devicetree/bindings/gpio/snps-dwapb-gpio.txt
+++ /dev/null
@@ -1,65 +0,0 @@
-* Synopsys DesignWare APB GPIO controller
-
-Required properties:
-- compatible : Should contain "snps,dw-apb-gpio"
-- reg : Address and length of the register set for the device.
-- #address-cells : should be 1 (for addressing port subnodes).
-- #size-cells : should be 0 (port subnodes).
-
-The GPIO controller has a configurable number of ports, each of which are
-represented as child nodes with the following properties:
-
-Required properties:
-- compatible : "snps,dw-apb-gpio-port"
-- gpio-controller : Marks the device node as a gpio controller.
-- #gpio-cells : Should be two.  The first cell is the pin number and
-  the second cell is used to specify the gpio polarity:
-      0 = active high
-      1 = active low
-- reg : The integer port index of the port, a single cell.
-
-Optional properties:
-- interrupt-controller : The first port may be configured to be an interrupt
-controller.
-- #interrupt-cells : Specifies the number of cells needed to encode an
-  interrupt.  Shall be set to 2.  The first cell defines the interrupt number,
-  the second encodes the triger flags encoded as described in
-  Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
-- interrupts : The interrupts to the parent controller raised when GPIOs
-  generate the interrupts. If the controller provides one combined interrupt
-  for all GPIOs, specify a single interrupt. If the controller provides one
-  interrupt for each GPIO, provide a list of interrupts that correspond to each
-  of the GPIO pins. When specifying multiple interrupts, if any are unconnected,
-  use the interrupts-extended property to specify the interrupts and set the
-  interrupt controller handle for unused interrupts to 0.
-- snps,nr-gpios : The number of pins in the port, a single cell.
-- resets : Reset line for the controller.
-
-Example:
-
-gpio: gpio@20000 {
-	compatible = "snps,dw-apb-gpio";
-	reg = <0x20000 0x1000>;
-	#address-cells = <1>;
-	#size-cells = <0>;
-
-	porta: gpio@0 {
-		compatible = "snps,dw-apb-gpio-port";
-		gpio-controller;
-		#gpio-cells = <2>;
-		snps,nr-gpios = <8>;
-		reg = <0>;
-		interrupt-controller;
-		#interrupt-cells = <2>;
-		interrupt-parent = <&vic1>;
-		interrupts = <0>;
-	};
-
-	portb: gpio@1 {
-		compatible = "snps,dw-apb-gpio-port";
-		gpio-controller;
-		#gpio-cells = <2>;
-		snps,nr-gpios = <8>;
-		reg = <1>;
-	};
-};
diff --git a/Documentation/driver-api/gpio/board.rst b/Documentation/driver-api/gpio/board.rst
index ce91518bf9f4..191fa867826a 100644
--- a/Documentation/driver-api/gpio/board.rst
+++ b/Documentation/driver-api/gpio/board.rst
@@ -113,13 +113,15 @@ files that desire to do so need to include the following header::
 GPIOs are mapped by the means of tables of lookups, containing instances of the
 gpiod_lookup structure. Two macros are defined to help declaring such mappings::
 
-	GPIO_LOOKUP(chip_label, chip_hwnum, con_id, flags)
-	GPIO_LOOKUP_IDX(chip_label, chip_hwnum, con_id, idx, flags)
+	GPIO_LOOKUP(key, chip_hwnum, con_id, flags)
+	GPIO_LOOKUP_IDX(key, chip_hwnum, con_id, idx, flags)
 
 where
 
-  - chip_label is the label of the gpiod_chip instance providing the GPIO
-  - chip_hwnum is the hardware number of the GPIO within the chip
+  - key is either the label of the gpiod_chip instance providing the GPIO, or
+    the GPIO line name
+  - chip_hwnum is the hardware number of the GPIO within the chip, or U16_MAX
+    to indicate that key is a GPIO line name
   - con_id is the name of the GPIO function from the device point of view. It
 	can be NULL, in which case it will match any function.
   - idx is the index of the GPIO within the function.
@@ -135,7 +137,10 @@ where
 
 In the future, these flags might be extended to support more properties.
 
-Note that GPIO_LOOKUP() is just a shortcut to GPIO_LOOKUP_IDX() where idx = 0.
+Note that:
+  1. GPIO line names are not guaranteed to be globally unique, so the first
+     match found will be used.
+  2. GPIO_LOOKUP() is just a shortcut to GPIO_LOOKUP_IDX() where idx = 0.
 
 A lookup table can then be defined as follows, with an empty entry defining its
 end. The 'dev_id' field of the table is the identifier of the device that will