Merge tag 'spi-v4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi

Pull spi updates from Mark Brown:
 "There's only one big change in this release but it's a very big
  change: Geert Uytterhoeven has implemented support for SPI slave mode.

  This feature has been on the cards since the subsystem was originally
  merged back in the mists of time so it's great that Geert stepped up
  and finally implemented it.

   - SPI slave support, together with wholesale renaming of SPI
     controllers from master to controller which went surprisingly
     smoothly. This is already used with Renesas SoCs and support is in
     the works for i.MX too.

   - New drivers for Meson SPICC and ST STM32"

* tag 'spi-v4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi: (57 commits)
  spi: loopback-test: Fix kfree() NULL pointer error.
  spi: loopback-test: fix spelling mistake: "reruning" -> "rerunning"
  spi: sirf: fix spelling mistake: "registerred" -> "registered"
  spi: stm32: fix potential dereference null return value
  spi: stm32: enhance DMA error management
  spi: stm32: add runtime PM support
  spi: stm32: use normal conditional statements instead of ternary operator
  spi: stm32: replace st, spi-midi with st, spi-midi-ns to fit bindings
  spi: stm32: fix example with st, spi-midi-ns property
  spi: stm32: fix compatible to fit with new bindings
  spi: stm32: use SoC specific compatible
  spi: rockchip: Disable Runtime PM when chip select is asserted
  spi: rockchip: Set GPIO_SS flag to enable Slave Select with GPIO CS
  spi: atmel: fix corrupted data issue on SAM9 family SoCs
  spi: stm32: fix error check on mbr being -ve
  spi: add driver for STM32 SPI controller
  spi: Document the STM32 SPI bindings
  spi/bcm63xx: Fix checkpatch warnings
  spi: imx: Check for allocation failure earlier
  spi: mediatek: add spi support for mt2712 IC
  ...

6 files changed, 159 insertions, 38 deletions

diff --git a/Documentation/devicetree/bindings/spi/sh-msiof.txt b/Documentation/devicetree/bindings/spi/sh-msiof.txt
index dc975064fa27..64ee489571c4 100644
--- a/Documentation/devicetree/bindings/spi/sh-msiof.txt
+++ b/Documentation/devicetree/bindings/spi/sh-msiof.txt
@@ -38,6 +38,8 @@ Optional properties:
 			 specifiers, one for transmission, and one for
 			 reception.
 - dma-names            : Must contain a list of two DMA names, "tx" and "rx".
+- spi-slave            : Empty property indicating the SPI controller is used
+			 in slave mode.
 - renesas,dtdl         : delay sync signal (setup) in transmit mode.
 			 Must contain one of the following values:
 			 0   (no bit delay)
diff --git a/Documentation/devicetree/bindings/spi/spi-bus.txt b/Documentation/devicetree/bindings/spi/spi-bus.txt
index 4b1d6e74c744..1f6e86f787ef 100644
--- a/Documentation/devicetree/bindings/spi/spi-bus.txt
+++ b/Documentation/devicetree/bindings/spi/spi-bus.txt
@@ -1,17 +1,23 @@
 SPI (Serial Peripheral Interface) busses
 
-SPI busses can be described with a node for the SPI master device
-and a set of child nodes for each SPI slave on the bus.  For this
-discussion, it is assumed that the system's SPI controller is in
-SPI master mode.  This binding does not describe SPI controllers
-in slave mode.
+SPI busses can be described with a node for the SPI controller device
+and a set of child nodes for each SPI slave on the bus.  The system's SPI
+controller may be described for use in SPI master mode or in SPI slave mode,
+but not for both at the same time.
 
-The SPI master node requires the following properties:
+The SPI controller node requires the following properties:
+- compatible      - Name of SPI bus controller following generic names
+		    recommended practice.
+
+In master mode, the SPI controller node requires the following additional
+properties:
 - #address-cells  - number of cells required to define a chip select
 		address on the SPI bus.
 - #size-cells     - should be zero.
-- compatible      - name of SPI bus controller following generic names
-		recommended practice.
+
+In slave mode, the SPI controller node requires one additional property:
+- spi-slave       - Empty property.
+
 No other properties are required in the SPI bus node.  It is assumed
 that a driver for an SPI bus device will understand that it is an SPI bus.
 However, the binding does not attempt to define the specific method for
@@ -21,7 +27,7 @@ assumption that board specific platform code will be used to manage
 chip selects.  Individual drivers can define additional properties to
 support describing the chip select layout.
 
-Optional properties:
+Optional properties (master mode only):
 - cs-gpios	  - gpios chip select.
 - num-cs	  - total number of chipselects.
 
@@ -41,28 +47,36 @@ cs1 : native
 cs2 : &gpio1 1 0
 cs3 : &gpio1 2 0
 
-SPI slave nodes must be children of the SPI master node and can
-contain the following properties.
-- reg             - (required) chip select address of device.
-- compatible      - (required) name of SPI device following generic names
-		recommended practice.
-- spi-max-frequency - (required) Maximum SPI clocking speed of device in Hz.
-- spi-cpol        - (optional) Empty property indicating device requires
-		inverse clock polarity (CPOL) mode.
-- spi-cpha        - (optional) Empty property indicating device requires
-		shifted clock phase (CPHA) mode.
-- spi-cs-high     - (optional) Empty property indicating device requires
-		chip select active high.
-- spi-3wire       - (optional) Empty property indicating device requires
-		3-wire mode.
-- spi-lsb-first   - (optional) Empty property indicating device requires
-		LSB first mode.
-- spi-tx-bus-width - (optional) The bus width (number of data wires) that is
-                      used for MOSI. Defaults to 1 if not present.
-- spi-rx-bus-width - (optional) The bus width (number of data wires) that is
-                      used for MISO. Defaults to 1 if not present.
-- spi-rx-delay-us  - (optional) Microsecond delay after a read transfer.
-- spi-tx-delay-us  - (optional) Microsecond delay after a write transfer.
+
+SPI slave nodes must be children of the SPI controller node.
+
+In master mode, one or more slave nodes (up to the number of chip selects) can
+be present.  Required properties are:
+- compatible      - Name of SPI device following generic names recommended
+		    practice.
+- reg             - Chip select address of device.
+- spi-max-frequency - Maximum SPI clocking speed of device in Hz.
+
+In slave mode, the (single) slave node is optional.
+If present, it must be called "slave".  Required properties are:
+- compatible      - Name of SPI device following generic names recommended
+		    practice.
+
+All slave nodes can contain the following optional properties:
+- spi-cpol        - Empty property indicating device requires inverse clock
+		    polarity (CPOL) mode.
+- spi-cpha        - Empty property indicating device requires shifted clock
+		    phase (CPHA) mode.
+- spi-cs-high     - Empty property indicating device requires chip select
+		    active high.
+- spi-3wire       - Empty property indicating device requires 3-wire mode.
+- spi-lsb-first   - Empty property indicating device requires LSB first mode.
+- spi-tx-bus-width - The bus width (number of data wires) that is used for MOSI.
+		    Defaults to 1 if not present.
+- spi-rx-bus-width - The bus width (number of data wires) that is used for MISO.
+		    Defaults to 1 if not present.
+- spi-rx-delay-us - Microsecond delay after a read transfer.
+- spi-tx-delay-us - Microsecond delay after a write transfer.
 
 Some SPI controllers and devices support Dual and Quad SPI transfer mode.
 It allows data in the SPI system to be transferred using 2 wires (DUAL) or 4
diff --git a/Documentation/devicetree/bindings/spi/spi-meson.txt b/Documentation/devicetree/bindings/spi/spi-meson.txt
index dc6d0313324a..825c39cae74a 100644
--- a/Documentation/devicetree/bindings/spi/spi-meson.txt
+++ b/Documentation/devicetree/bindings/spi/spi-meson.txt
@@ -20,3 +20,34 @@ Required properties:
 		#address-cells = <1>;
 		#size-cells = <0>;
 	};
+
+* SPICC (SPI Communication Controller)
+
+The Meson SPICC is generic SPI controller for general purpose Full-Duplex
+communications with dedicated 16 words RX/TX PIO FIFOs.
+
+Required properties:
+ - compatible: should be "amlogic,meson-gx-spicc" on Amlogic GX SoCs.
+ - reg: physical base address and length of the controller registers
+ - interrupts: The interrupt specifier
+ - clock-names: Must contain "core"
+ - clocks: phandle of the input clock for the baud rate generator
+ - #address-cells: should be 1
+ - #size-cells: should be 0
+
+Optional properties:
+ - resets: phandle of the internal reset line
+
+See ../spi/spi-bus.txt for more details on SPI bus master and slave devices
+required and optional properties.
+
+Example :
+	spi@c1108d80 {
+		compatible = "amlogic,meson-gx-spicc";
+		reg = <0xc1108d80 0x80>;
+		interrupts = <GIC_SPI 112 IRQ_TYPE_LEVEL_HIGH>;
+		clock-names = "core";
+		clocks = <&clk81>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+	};
diff --git a/Documentation/devicetree/bindings/spi/spi-mt65xx.txt b/Documentation/devicetree/bindings/spi/spi-mt65xx.txt
index e43f4cf4cf35..e0318cf92d73 100644
--- a/Documentation/devicetree/bindings/spi/spi-mt65xx.txt
+++ b/Documentation/devicetree/bindings/spi/spi-mt65xx.txt
@@ -3,7 +3,9 @@ Binding for MTK SPI controller
 Required properties:
 - compatible: should be one of the following.
     - mediatek,mt2701-spi: for mt2701 platforms
+    - mediatek,mt2712-spi: for mt2712 platforms
     - mediatek,mt6589-spi: for mt6589 platforms
+    - mediatek,mt7622-spi: for mt7622 platforms
     - mediatek,mt8135-spi: for mt8135 platforms
     - mediatek,mt8173-spi: for mt8173 platforms
 
diff --git a/Documentation/devicetree/bindings/spi/spi-stm32.txt b/Documentation/devicetree/bindings/spi/spi-stm32.txt
new file mode 100644
index 000000000000..1b3fa2c119d5
--- /dev/null
+++ b/Documentation/devicetree/bindings/spi/spi-stm32.txt
@@ -0,0 +1,59 @@
+STMicroelectronics STM32 SPI Controller
+
+The STM32 SPI controller is used to communicate with external devices using
+the Serial Peripheral Interface. It supports full-duplex, half-duplex and
+simplex synchronous serial communication with external devices. It supports
+from 4 to 32-bit data size. Although it can be configured as master or slave,
+only master is supported by the driver.
+
+Required properties:
+- compatible: Must be "st,stm32h7-spi".
+- reg: Offset and length of the device's register set.
+- interrupts: Must contain the interrupt id.
+- clocks: Must contain an entry for spiclk (which feeds the internal clock
+	  generator).
+- #address-cells:  Number of cells required to define a chip select address.
+- #size-cells: Should be zero.
+
+Optional properties:
+- resets: Must contain the phandle to the reset controller.
+- A pinctrl state named "default" may be defined to set pins in mode of
+  operation for SPI transfer.
+- dmas: DMA specifiers for tx and rx dma. DMA fifo mode must be used. See the
+  STM32 DMA bindings, Documentation/devicetree/bindings/dma/stm32-dma.txt.
+- dma-names: DMA request names should include "tx" and "rx" if present.
+- cs-gpios: list of GPIO chip selects. See the SPI bus bindings,
+  Documentation/devicetree/bindings/spi/spi-bus.txt
+
+
+Child nodes represent devices on the SPI bus
+  See ../spi/spi-bus.txt
+
+Optional properties:
+- st,spi-midi-ns: (Master Inter-Data Idleness) minimum time delay in
+		  nanoseconds inserted between two consecutive data frames.
+
+
+Example:
+	spi2: spi@40003800 {
+		#address-cells = <1>;
+		#size-cells = <0>;
+		compatible = "st,stm32h7-spi";
+		reg = <0x40003800 0x400>;
+		interrupts = <36>;
+		clocks = <&rcc SPI2_CK>;
+		resets = <&rcc 1166>;
+		dmas = <&dmamux1 0 39 0x400 0x01>,
+		       <&dmamux1 1 40 0x400 0x01>;
+		dma-names = "rx", "tx";
+		pinctrl-0 = <&spi2_pins_b>;
+		pinctrl-names = "default";
+		cs-gpios = <&gpioa 11 0>;
+
+		aardvark@0 {
+			compatible = "totalphase,aardvark";
+			reg = <0>;
+			spi-max-frequency = <4000000>;
+			st,spi-midi-ns = <4000>;
+		};
+	};
diff --git a/Documentation/spi/spi-summary b/Documentation/spi/spi-summary
index d1824b399b2d..1721c1b570c3 100644
--- a/Documentation/spi/spi-summary
+++ b/Documentation/spi/spi-summary
@@ -62,8 +62,8 @@ chips described as using "three wire" signaling: SCK, data, nCSx.
 (That data line is sometimes called MOMI or SISO.)
 
 Microcontrollers often support both master and slave sides of the SPI
-protocol.  This document (and Linux) currently only supports the master
-side of SPI interactions.
+protocol.  This document (and Linux) supports both the master and slave
+sides of SPI interactions.
 
 
 Who uses it?  On what kinds of systems?
@@ -154,9 +154,8 @@ control audio interfaces, present touchscreen sensors as input interfaces,
 or monitor temperature and voltage levels during industrial processing.
 And those might all be sharing the same controller driver.
 
-A "struct spi_device" encapsulates the master-side interface between
-those two types of driver.  At this writing, Linux has no slave side
-programming interface.
+A "struct spi_device" encapsulates the controller-side interface between
+those two types of drivers.
 
 There is a minimal core of SPI programming interfaces, focussing on
 using the driver model to connect controller and protocol drivers using
@@ -177,10 +176,24 @@ shows up in sysfs in several locations:
    /sys/bus/spi/drivers/D ... driver for one or more spi*.* devices
 
    /sys/class/spi_master/spiB ... symlink (or actual device node) to
-	a logical node which could hold class related state for the
-	controller managing bus "B".  All spiB.* devices share one
+	a logical node which could hold class related state for the SPI
+	master controller managing bus "B".  All spiB.* devices share one
 	physical SPI bus segment, with SCLK, MOSI, and MISO.
 
+   /sys/devices/.../CTLR/slave ... virtual file for (un)registering the
+	slave device for an SPI slave controller.
+	Writing the driver name of an SPI slave handler to this file
+	registers the slave device; writing "(null)" unregisters the slave
+	device.
+	Reading from this file shows the name of the slave device ("(null)"
+	if not registered).
+
+   /sys/class/spi_slave/spiB ... symlink (or actual device node) to
+	a logical node which could hold class related state for the SPI
+	slave controller on bus "B".  When registered, a single spiB.*
+	device is present here, possible sharing the physical SPI bus
+	segment with other SPI slave devices.
+
 Note that the actual location of the controller's class state depends
 on whether you enabled CONFIG_SYSFS_DEPRECATED or not.  At this time,
 the only class-specific state is the bus number ("B" in "spiB"), so